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1
Fry, Charles Alan. "Measurement of the Lamb shift in muonium." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25785.
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This thesis describes the first measurement of the Lamb shift in n=2 muonium. The muonium atom is a hydrogen-like bound state of two leptons (µ⁺e⁻), both of which are believed to be point-like particles. The point-like nature of the constituent particles simplifies and reduces the uncertainty of the application of quantum electrodynamics (QED) to the calculation of the Lamb shift in the muonium atom. Measurements of the Lamb shift in hydrogen disagree with the predictions of theory by a few standard deviations; however, theoretical predictions also disagree with each other, partly because of difficulties associated with the treatment of the proton structure. Thus a measurement in the muonium system of similar precision to those already made in the hydrogen system will be a valuable test of QED. The present experiment is not intended to test QED. It is an investigation of the methods and techniques necessary to
surmount the difficulties presented by the nature of muonium. The available number of muonium atoms is about 10⁺¹º times less than that of hydrogen used by Lamb in his first measurement. The value obtained for the n=2 muonium Lamb shift 1070⁺¹²₋₁₅ MHz. The uncertainty quoted is statistical at the 68% confidence level. Systematic effects were found to contribute to a further 2 MHz uncertainty.Science, Faculty of
Physics and Astronomy, Department of
Graduate
2
Spencer, David Philip. "Muonium in some insulating oxides and diamond." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25972.
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Muonium can be regarded as an isotopic analogue of the hydrogen atom, with a positive muon replacing the proton. This thesis is concerned with searches for muonium in weak transverse and zero magnetic fields in a variety of non-magnetic oxide insulators with few nuclear moments, and in diamond, a semiconductor. The technique of Muon Spin Rotation (µSR) was used, which can be thought of in analogy with NMR and EPR. It relies on measuring the direction of the muon spin with time via the unique signature of the parity violating decay of the muon, in which its decay positron is emitted preferentially along the muon spin direction. This can provide a sensitive measure of the interaction of the muon spin with its environment.
Muonium has been searched for successfully in ɑ-quartz, fused quartz., hexagonal and fused germanium dioxide, magnesium oxide, and diamond; and unsuccessfully in tetragonal germanium dioxide, rutile, strontium titanate, zircon, and beryl. All the samples save the quartzes showed a large "missing fraction"; that is, not all the initial muon polarization could be accounted for. This indicates that muonium was formed but rapidly depolarized. The missing fractions were found to be very strongly temperature dependent in strontium titanate but only weakly in rutile. At room temperature, the observed muonium fractions were: ɑ-quartz and fused quartz (65±5)%, hexagonal germanium dioxide <2%, fused germanium dioxide (10±4)%, magnesium oxide (30±10)%, and diamond (33± 4)%. It is noteworthy that the fractions are very different in quartz and germanium dioxide, despite their structural analogy. The observation of muonium in diamond represents the first time that muonium has been seen in a room temperature semiconductor.
A spin-Hamiltonian new to µSR was found in low-temperature ɑ-quartz and hexagonal germanium dioxide, in which the hyperfine interaction is completely anisotropic. In low-temperature ɑ-quartz in zero magnetic field this interaction gives rise to three signals whose frequencies are orientation independent, but whose amplitudes are strongly orientation dependent By studying the orientation dependence it was determined that muonium occupies a site which is identical with that seen for hydrogen in EPR studies. This was the first time that muonium was shown to behave just like an isotope of hydrogen in a solid. In hexagonal GeO₂, eight frequencies were observed at 6K, in marked contrast to the observation of only three frequencies in structurally analogous ɑ-quartz. The interpretation of this is that there are three or four different sites, the exact nature of which has not been determined.Science, Faculty of
Chemistry, Department of
Graduate
3
Morris, Gerald D. "Muonium formation and diffusion in cryocrystals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq27205.pdf.
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4
Barnabas, Mary Vijayarani. "Reactions of muonium and positronium in solution." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29007.
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Positive muons are produced at TRIUMF as pion decay products and form muo-nium atoms in media such as water during their two microsecond lifetime. Muo-nium is a hydrogen-like atom with virtually the same Bohr radius and ionization energy as ¹H, ²H and ³H, but with a mass one-ninth that of ¹H. Its reactions toward solutes are studied by μSR (the muon spin rotation technique) and the muonated free radicals it forms are studied by μLCR (muon level crossing resonance spectroscopy).
In this thesis, rate constants for muonium reactions were determined for a range of solutes from simple amides to DNA bases. Their values ranged from <10⁵ M⁻¹s⁻¹ to >10¹⁰M⁻¹s⁻¹. Kinetic isotope effects (relative to-¹H) varied from 100 to 0.01 depending on the reaction-type. In the presence of added micelles the rates of some abstraction reactions were very greatly enhanced, whereas most addition reactions were unaffected by the micellar microenvironment. Muonium was seen by LCR spectroscopy to add at a diffusion-limited rate across thiocarbonyl groups, with muonium attached to the carbon and thus yielding thiyl radicals. Uracil and thymine were studied by both μSR and LCR and their relative addition probabilities at C(5) and C(6) were determined.
Ortho-positronium (the atom consisting of an electron-positron pair with parallel spins) was studied by the positron annihilation lifetime technique for comparison with muonium in most of these same solutions. Its reactions are different, not 'adding' or 'abstracting' for instance, and it shows none of the properties of a hydrogen isotope.Science, Faculty of
Chemistry, Department of
Graduate
5
Harshman, Dale Richard. "The interactions of muonium with silica surfaces." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27108.
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The behavior of muonium on the surface of fine (35 Å mean radius) SiO₂ powders has been studied using the techniques of muon spin rotation (μSR). Results indicate diffusion and trapping behavior of the muonium atoms on the silica surface, which is strongly influenced by the concentration of surface hydroxyl groups. Specifically, the presence of the surface hydroxyl groups has been shown to inhibit the motion of muonium on the silica surface.
These studies have also provided information regarding the origin of the relaxation of the muon spin polarization for muonium on the silica surface. Specifically, a random anisotropic distortion of the muonium hyperfine interaction, induced by the local surface environment of the muonium atom, has been shown to be a principal contributor to the relaxation of the muon ensemble spin polarization, whereas the random local magnetic fields due to the neighboring hydroxyl protons were found to play only a minor role. From this result, the observed strong dependence of the relaxation on the surface hydroxyl concentration has been attributed to an associated hyperfine distortion, induced by the neighboring hydroxyls. A new spin relaxation theory, for the case of random anisotropic hyperfine distortions, has also been developed to explain the data.
Gas adsorption isotherm studies were also performed, with ⁴He at 6 K, which show the muonium asymmetry to be strongly influenced by the fractional surface coverage. These results clearly indicate that the muonium formation probability decreases with increasing surface coverage, suggesting that the charge exchange cross section at the silica surface is significant. The implication of these results with regard to the origins of muonium formation (i.e., surface or bulk formation) is as yet unclear, however, since the precise role played by the adsorbed helium atoms is not known.
These investigations have also been extended to platinum loaded silica, where the first surface reaction of muonium has been observed; the reaction rate of muonium with the surface of oxygen-covered platinum microcrystals was found to be 3.5 ± 0.15 μs⁻¹.Science, Faculty of
Physics and Astronomy, Department of
Graduate
6
Tempelmann, Alexandra. "Reaction kinetics of muonium with hydrogen bromide." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30385.
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The rate constants of the abstraction reaction Mu + HBr —• MuH + Br were measured using the well established μSR technique at TRIUMF. Measurements were made at various temperatures between 170 and 480 K, and fit to the Arrhenius equation both with and without an additional T½ dependence. The rate constants obtained were k(T) = (5.101 ± 0.106) x 10⁻¹¹ exp{-(0.560 ± 0.110) kcal mol⁻¹/RT} and k(T) = (0.183 ± 0.005) x 10⁻¹¹T½exp{-(0.286± 0.014) kcal mol⁻¹/RT} cm³ molecule⁻¹ s⁻¹. The low activation energy for such an exothermic reaction indicates that the barrier on the Mu + HBr surface is early. Kinetic isotope effects of the H/Mu + HBr reactions along with a lack of curvature in the Mu + HBr Arrhenius plot suggest that tunneling is relatively unimportant down to 170 K.Science, Faculty of
Chemistry, Department of
Graduate
7
Yen, Hon Kit. "Theoretical spin dynamics on muonium level-crossing resonance." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28531.
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Redfield's theory and the theory of master equations have been reviewed and their applications to muonium spin dynamics discussed. It was found that both theories
are equivalent in the Markov limit. In some cases, analytical expressions for relaxation rates are found. In addition, Redfield's theory was applied to describe spin relaxation of muonium-substituted free radicals near level-crossing resonances. Theoretical predictions were compared with experimental data for the C₆F₆-Mu radical and the results suggest there are several relaxation mechanisms involved.Science, Faculty of
Physics and Astronomy, Department of
Graduate
8
Hubbard, Penny Louise. "Molecular and electron dynamics with muon spectroscopy." Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268573.
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9
Bakule, Pavel. "A solid state laser system for Doppler-free spectroscopy of muonium." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365885.
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10
Kerridge, Andrew. "Quantum behaviour of hydrogen and muonium in solid-state and biological systems." Thesis, University College London (University of London), 2004. http://discovery.ucl.ac.uk/1446780/.
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For hydrogen-like nuclei (HLN) such as the proton or muon, the quantum zero point energy cannot be ignored. The main objectives of this thesis were to identify practical ways to model this quantatively, and hence i) to gain an understanding of interactions between the HLN and its environment, and ii) to use this understanding to evaluate the wavefunction of such a nucleus within an electronic structure calculation. Several features of the HLN-electron interactions were studied analytically by assuming their interaction to be harmonic in nature. It was shown that the accurate modelling of the HLN-electron correlation was extremely important in the evaluation of the HLN wavefunction. A parametrised correlation model (PCM) was developed, and was shown to accurately reproduce the effective potential energy surface experienced by the HLN when HLN-electron correlation was included. The required parameters showed a simple HLN mass dependence. The PCM was used to study DNA base molecule adducts formed by addition of a single HLN. The relative stability of these adducts was shown to be dependent on the mass of the HLN, and the inclusion of HLN-electron correlation was shown to lead to a stabilisation of the C-X bonds relative to the N-X and O-X bonds. The PCM was used to study the interaction of H and Mu with the diamond dopants sulphur and phosphorus. The PCM correctly predicted differences between the HLN wavefunctions in crystalline and molecular environments. The HLN-electron correlation energy was shown to be large enough to cause the phosphorus-muonium defect complex formation energy to become positive. HLN-impurity-vacancy complexes in diamond were studied using the PCM, and it was found that the lowest energy state was obtained by the HLN saturating a carbon dangling bond, irrespective of the impurity species. It was concluded that the HLN would be effectively localised at a single site.
11
Cornish, Simon Lee. "A solid state laser system for high resolution spectroscopy of the 1S-2S transition in muonium." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297937.
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12
Liu, Yi-Wei. "Optical studies using tunable solid state lasers." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299523.
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13
Souiri, Moncef. "Correlation entre les paramètres de résonance paramagnétique et de la liaison chimique ions des métaux de transition et muonium /." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37601312f.
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14
Souiri, Moncef. "Correlation entre les parametres de resonance paramagnetiques et de la liaison chimique : ions des metaux de transition et muonium." Strasbourg 1, 1986. http://www.theses.fr/1987STR13213.
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Recherche de relations entre parametres de l'hamiltonien de spin en rpe de defauts ponctuels (decomposition par le champ cristallin, constante de couplage hyperfin) et les parametres de la liaison chimique du reseau hote (ionicite, electronegativites de l'anion et du cation, longueur de liaison). Bonne correlation dans le cas de l'ionicite et de l'electronegativite de l'anion; absence de correlation avec la longueur de liaison, explicable par une relaxation locale, et mise en evidence dans les matrices ternaires. Application de l'analyse au muonium: la constante de couplage hyperfin est correlee a l'electronegativite du cation dans le cas du muonium normal, qui serait localise seulement dans les cristaux covalents; cette constante est tres faible pour le muonium anormal qui serait engage dans une liaison covalente avec le voisin le plus proche
15
Dupays, Arnaud. "Transfert de charge muonique." Phd thesis, Université Paul Sabatier - Toulouse III, 2004. http://tel.archives-ouvertes.fr/tel-00006442.
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Cette thèse traite du transfert du muon entre l'hydrogène muonique et d'autres atomes et molécules. Récemment, Adamczak et al. ont proposé une méthode de mesure de la structure hyperfine de l'état fondamental de l'hydrogène muonique basée sur la dépendance énergétique du taux de transfert muonique sur l'oxygène. Réalisées dans les années 90 au Paul Scherrer Institut, des expériences ont en effet indiqué que le taux de transfert sur l'oxygène semblait augmenter d'un facteur 4 entre des énergies de collision thermiques (0.04 eV) et épithermiques (0.12 eV). Nos calculs avaient pour première motivation de vérifier ce comportement. Pour étudier cette dépendance du taux de transfert, nous avons utilisé une méthode de résolution de l'équation de Schrödinger indépendante du temps du type close-coupling. Nous avons ainsi mis en oeuvre un formalisme utilisant les coordonnées hypersphériques elliptiques étendu pour traiter le cas d'un moment angulaire total différent de zéro. Nous avons utilisé ce formalisme pour calculer le processus de transfert sur l'oxygène et le néon. Dans ces deux cas, l'accord avec les résultats expérimentaux est excellent. Finalement, la dépendance énergétique du taux de transfert sur le néon suggère de préférer plutôt le néon à l'oxygène pour réaliser l'expérience de mesure de la structure hyperfine de l'hydrogène muonique. Les effets isotopiques (lorsque l'hydrogène muonique est remplacé par le deutérium muonique) sont aussi parfaitement reproduits et expliqués pour l'azote, l'oxygène et le néon.
16
Komu, T. (Teresa). "Retoriikkaa vai sosiaalista kestävyyttä?:poronhoitoyhteisöjen osallistaminen kaivostoiminnan suunnitteluprosesseissa Muonion Lapinkylässä ja Muonion paliskunnassa 2011–2012." Master's thesis, University of Oulu, 2013. http://urn.fi/URN:NBN:fi:oulu-201304251209.
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Tutkimuksen aiheena on poronhoitoyhteisöjen osallistaminen kaivostoiminnan suunnitteluprosesseissa. Tutkimuskohteena on kansainvälisen kaivosyhtiön Ruotsin Pajalaan ja Suomen Kolariin suunnittelema hankekokonaisuus. Hankkeet sijoittuvat Muonion lapinkylän ja Muonion paliskunnan laidunmaille. Suomessa on parasta aikaa vireillä useita kaivosprojekteja, joista valtaosa sijoittuu poronhoitoalueelle. Sekä kaivosalalla että poronhoitoyhteisöillä on tarve saada tietoa kyseisten elinkeinojen yhteensovittamisesta.
Tutkimusta varten haastateltiin osallistamisprosessissa keskeisessä roolissa olevia poronhoitajia sekä kaivosyhtiön edustajia. Haastatteluja tehtiin yhteensä kymmenen. Keskeisenä osana vuosien 2011–2012 aikana kerättyä aineistoa on kolme Kolariin tehtyä kenttätyömatkaa. Kenttätöiden aikana tehtiin osallistuvaa havainnointia yhteensä kuudessa Kolarin kaivoshankkeeseen liittyvässä kokouksessa.
Tapaustutkimuksen teoreettisena näkökulmana on poliittinen ekologia. Työssä selvitetään, mitä valittu tapaustutkimus kertoo osallistamiseen linkittyvästä vallankäytöstä ja sosiaalisen toimiluvan käsitteen soveltuvuudesta osallistavan suunnittelun tutkimukseen. Poronhoitoyhteisöjen kokemusten avulla määritetään, kuinka poronhoitajat voitaisiin osallistaa kaivoshankkeiden suunnitteluprosessiin näille toimivimmalla tavalla. Lisäksi pohditaan, kuinka osallistaminen tulisi määritellä, jotta sillä edistettäisiin sosiaalista kestävyyttä.
Sosiaalisen toimiluvan käsite on liian retorinen ja näkökulmaltaan yhtiö-keskeinen soveltuakseen osallistavan suunnittelun tarkasteluun paikallisnäkökulmasta. Osallistaminen tulisi määritellä sisältämään sekä neuvottelun hankkeen vaikutuksista ja toteuttamisesta että hankkeen negatiivisten vaikutusten korvaamisen ja lieventämisen. Poronhoitajien osallistamisessa tulisi huomioida elinkeinon erityispiirteet ja kiireiset työsesongit. Yhteydenpidon poronhoitoyhteisöjen kanssa ja hankkeen vaikutusten seurannan tulee jatkua virallisen ympäristövaikutusten arviointiprosessin päättymisen jälkeenkin.
17
Rusjan, Edmond. "Transport of muonic atoms." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/81032.
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Transport of muonic hydrogen and deuterium atoms in gaseous hydrogen and deuterium is studied in the diffusion approximation and by means of the multiple collision expansion. The diffusion coefficient is derived. Scattering kernels are computed from the kinematics of an inelastic binary collision. The effect of rotations of the target molecules is treated by defining and computing an effective inelastic energy transfer Qeff. The Doppler effect is taken into account by averaging the cross sections over the Maxwellian velocity distribution of the target molecules. Numerical results of the time-dependent problem in slab geometry are presented.
In part two we construct a candidate for a realistic four generation Calabi-Yau manifold by dividing an algebraic variety in CP₄ x CP₄ with the Z₂ x Z₂ symmetry. A nontrivial embedding of Z₂ x Z₂ in E(6) allows the physically interesting intermediate symmetry, based on Pati-Salam SU(2)L x SU(2)R x SU(4)C group. The group of honest symmetries GH of the manifold is identified and the transformations properties of quark and lepton fields under GH are given.Ph. D.
18
Tolonen, S. (Siiri). "Uhraamisen sijoittuminen seidoilla:geokemiallisia ja -fysikaalisia havaintoja ja tilallista tulkintaa Enontekiön Näkkälän, Utsjoen Sieiddakeädgin, Muonion Kirkkopahdan ja Muonion Porviniemen seitakohteilta." Master's thesis, University of Oulu, 2013. http://urn.fi/URN:NBN:fi:oulu-201305131227.
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Tutkielma käsittelee uhraamisen sijoittumista seidoilla. Aineistona on neljältä seidalta, Enontekiön Näkkälästä, Utsjoen Sieiddakeädgiltä, Muonion Kirkkopahdalta ja Muonion Porviniemeltä, kerätyt maaperänäytteet. Tutkimuksessa selvitetään, onko kohteilla uhrattu, ja mihin uhrit on asetettu. Lisäksi pohditaan, miksi uhraaminen näyttää sijoittuvan kohteiden tietyille alueille, ja onko kohteiden välillä havaittavissa samankaltaisuuksia vai eroja. Näytteistä analysoidaan fosforipitoisuus sitruunahappomenetelmällä, magneettinen suskeptibiliteetti ennen ja jälkeen näytteiden polton, pH sekä orgaanisen aineksen pitoisuus kuivapolttomenetelmällä. Tulostenkäsittelyssä käytetään tilastollisia ja GIS-analyyseja. Tulosten tulkinnassa analogian lähteenä käytetään saamelaisia koskevia etnografisia lähteitä ja tuloksia verrataan kaivausaineistoon. Tulkinnassa sovelletaan myös Yi-Fu Tuanin esittämiä tulkintoja tilan hahmottamisesta. Tulosten perusteella Näkkälässä, Sieiddakeädgillä ja Kirkkopahdalla on merkkejä eläinperäisten tuotteiden uhraamisesta. Porviniemen tulos on epäselvä. Analyyseista fosforianalyysi osoittautui hyödyllisimmäksi. Muilla analyyseilla ei voitu havaita mitään ihmistoimintaan viittaavaa. Näkkälässä uhraaminen keskittyy seitakiven ympärille kummun päälle. Sieiddakeädgillä ja Kirkkopahdalla uhraaminen sijoittuu tietylle puolelle seitaa. Näkkälässä ja Kirkkopahdalla uhrausalue rajautuu hyvin lähelle seitaa, kun taas Sieiddakeädgillä on merkkejä laajemmasta toiminnasta, mikä voi liittyä uhrien siirtämiseen. Sieiddakeädgin maaperäanalyysien tulokset tukevat kaivaustuloksia, Näkkälässä taas toiminta on luultua laaja-alaisempaa. Kirkkopahdalta ei ole vanhoja uhrilöytöjä, joten maaperäanalyysit antavat uuttaa tietoa paikan käytöstä. Uhrien sijoittamista on ohjannut seidan ulkomuoto, lähiympäristön pinnanmuodot ja kasvillisuus. Vanhojen uhrien näkyminen on voinut ohjata uhraajia asettamaan uhrinsa samoille paikoille. Uhrien näkyville asettaminen viittaa siihen, että tietynlaisen uhrin antaminen on ollut tapa korostaa omaa asemaa yhteisössä. Seidat on nähty ihmismäisinä olentoina, joiden tapa hahmottaa ympäröivää tilaa perustuu siten samoihin käsitteisiin kuin ihmisellä; näitä ovat ylä- ja alapuoli, vasen ja oikea puoli, sekä etu- ja takapuoli. Eri puolille on voitu antaa symbolisia merkityksiä, jotka perustuvat ihmisruumiin ominaisuuksiin ja toimintaan. Nämä merkitykset ovat voineet vaikuttaa uhrien asetteluun. Kohteilla vasemman ja oikean puolen välillä ei ole arkeologisesti havaittavia eroja. Näkkälässä uhraaminen sijoittuu kummun päälle, mikä voi liittyä ylä- ja alapuolelle annettuihin merkityksiin. Kirkkopahdalla ja Sieiddakeädgillä uhraaminen tietylle puolelle seitaa voi liittyä siihen, että näitä on pidetty seitojen etupuolina. Vastaavanlaisissa tutkimuksissa näytteenotto olisi hyvä suorittaa ensin laajemmalta alueelta pidemmällä näytteenottovälillä, minkä jälkeen alue rajataan pienemmäksi ja näytteitä otetaan tiheämmin. Seitojen tunnistamiseen näytteitä voidaan ottaa pienemmältä alueelta ja jonkin verran pidemmällä näytteenottovälillä.
19
Nebel, Tobias. "The Lamb Shift in Muonic Hydrogen." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-120947.
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Antognini, Aldo. "The Lamb Shift Experiment in Muonic Hydrogen." Diss., lmu, 2005. http://nbn-resolving.de/urn:nbn:de:bvb:19-50441.
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21
Viel, David William. "Muon transfer from muonic deuterium to carbon." W&M ScholarWorks, 1994. https://scholarworks.wm.edu/etd/1539623853.
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Negative muons were brought to rest in a gas mixture of 30 torr CH$\sb4$ and 570 torr D$\sb2$, using the cyclotron trap at PSI. The muons formed muonic deuterium atoms which diffused through the mixture and transferred their muons to the carbon of the CH$\sb4$ molecules. A planar germanium detector and a silicon detector were used to observe x-rays from the initial muon cascade in the deuterium, and from subsequent cascade in the muonic carbon after transfer. A transfer rate of (4.5 $\pm$ 1.8) $\times$ 10$\sp{10}$/sec was found which agrees well with a previous result measured at 50 bar of (5.1 $\pm$ 1.0) $\times$ 10$\sp{10}$/sec. Transfer was found to occur predominantly to the n = 4 state in $\mu$C. The initial angular momentum state distribution in the $\mu$C was constructed using the cascade program of V. Markushin, and found to be consistent with any combination of two possible initial distributions (I 0.252 (4s) + 0.409 (4f) + 0.339 (4p)) and (II 0.284 (4d)+ 0.377 (4f) + 0.339 (4p)). The transfer theories of Gershtein and that of Holtzwarth and Pfeifer both agree well with the measured transfer rate and initial energy state, but not with the initial angular momentum distributions. The 2S population in $\mu$C was also determined to lie between 5% and 11%, which is higher than the 3% population in direct capture.
22
Bach, Bernard Wilhelm. "Search for metastability of 2S muonic neon." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539623869.
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An experiment was performed at the Paul Scherrer Institut (PSI) to establish the conditions for the metastability of the 2S-state of muonic neon. The muonic atoms were formed by stopping negative muons in the neon-filled target chamber of the PSI cyclotron trap. A pair of intrinsic germanium detectors were used in coincidence to search for the two photon decay of the 2S-state. Both energy and time information from two photon events were written to disk for off-line analysis. Data were accumulated for neon pressures of 40 and 400 Torr. The data were then searched for evidence of two photon transitions from the 2S-state.;The germanium detectors were sensitive to the K-, L- and M- series x-ray photons (with energies between 10 and 300 keV) emitted during the cascade of the muonic neon ion. The detectors were also used alone to record single photon events of the K- and L-series x rays. The observed intensity ratios of the K-series x rays provided a lower limit on the initial population of the 2S-state.;For the pressure condition of 40 Torr of neon, the 2S population was found to be 1.75% {dollar}\pm{dollar}.15% of the total cascade. The number of events at 40 Torr that could be attributed to two photon decays of the 2S-state was found to be 30 {dollar}\pm{dollar} 52 corresponding to a 2S population of 3.8% {dollar}\pm{dollar} 6.5%. at 400 Torr of neon the observed number of 2S two photon decays was 7 {dollar}\pm{dollar} 41, placing an upper limit on the 2S population at 0.9% {dollar}\pm{dollar} 5.1% of the total cascade. These results, to within the experimental uncertainties, can neither establish nor exclude the metastability of 2S muonic neon.
23
Lunerti, Leonardo. "Misura di efficienza del trigger muonico dell'esperimento CMS a LHC." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14093/.
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In questo lavoro è stata studiata l'efficienza del trigger muonico dell'esprimento CMS (Compact
Muon Solenoid) a LHC (Large Hadron Collider ), e, per la realizzazione di questo lavoro, è stato
sviluppato un programma in C++ che sfrutta il pacchetto software di analisi dati ROOT.
La misura dell'efficienza è stata ottenuta con il metodo detto del data-set ortogonale, utilizzando
i dati raccolti nel 2016. I risultati sono stati trovati in accordo con quelle provenienti
da misure dell'efficienza realizzate con il metodo del Tag & Probe.
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Clark, Jessica Higgins Deseret. "The ortho to para transition in muonic molecular hydrogen." W&M ScholarWorks, 2002. https://scholarworks.wm.edu/etd/1539623408.
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A precise measurement of the induced weak pseudoscalar coupling constant of the proton, gp, is of interest as a basic test of chiral symmetry breaking. This is the least well-known weak form factor of the nucleon. Muon capture experiments [Jonkmans et al., Phys. Rev. Lett. 77(1996)4512] have been used to measure gp. However, the interpretation of these muon capture experiments requires knowledge of the relative population of the muonic atomic and molecular states for muons in liquid hydrogen. In particular, lambda op, the transition rate between the ortho- and para-molecular states of the pmup molecule, needs to be known with precision. The only previous measurement [Bardin et al., Phys. Lett. 104B(1981)320.] of lambda op yielded a value of (4.1 +/- 1.4) x 10 4 s-1, significantly different than the theoretical prediction [Bakalov et al., Nucl. Phys. A384(1982)302.] of 7.1 x 104 s-1. A measurement of lambdaop using the time distribution of neutrons from muon capture was performed at TRIUMF during June--July 1999 and November 1999. The lambdaop measured in this experiment is (13.8 +/- 1.6) x 104 s-1 . The uncertainty is dominated by the statistical precision of the fit and the background due to the deuterium contamination in the protium target. The implications of this result for gp are discussed.
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Kraiman, James Brian. "The diffusion of muonic deuterium atoms in deuterium gas." W&M ScholarWorks, 1989. https://scholarworks.wm.edu/etd/1539623780.
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Negative muons were brought to rest in a target array consisting of 30-50 parallel plastic foils coated with Au which were separated by a few mm. The interstitial volumes between the foils were filled with deuterium gas at pressures from 0.094 bar to 1.52 bar. Muons which stopped in the deuterium formed {dollar}\mu{dollar}d atoms, which subsequently diffused through the gas until either the muon decayed or the {dollar}\mu{dollar}d atom struck a foil surface. For {dollar}\mu{dollar}d atoms impinging upon the Au layer, the muon would transfer to an Au atom, resulting in the formation of a {dollar}\mu{dollar}Au atom in a highly excited state. De-excitation to the 1S ground state resulted in emission of characteristic muonic Au x rays, and after the muon was absorbed by the Au nucleus, the emission of Pt {dollar}\gamma{dollar} rays. These transfer photons were detected by one of four germanium x-ray detectors adjacent to the target vessel. Analysis of the time distributions formed by collecting delayed transfer events for several sets of experimental conditions yielded information on the diffusion process of {dollar}\mu{dollar}d atoms in deuterium gas.;The initial speed distribution of the {dollar}\mu{dollar}d atoms upon reaching the 1S state is described reasonably well by a Maxwellian speed distribution of mean energy 3KT/2 = 1.8 {dollar}\pm{dollar} 0.1 eV. The theoretical scattering cross sections for the reaction {dollar}\mu{dollar}d + d {dollar}\to{dollar} {dollar}\mu{dollar}d + d calculated by Bubak and Faifman agree well with this experiment when the effects of molecular scattering are approximated by multiplying the nuclear cross sections by a factor of about two. It was found that a factor of 2.10 for center of mass collision energies greater than 0.30 eV, and 2.30 for collision energies less than 0.30 eV provided a good fit to the experimental data.
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Chen, Guo Fu. "The diffusion of muonic hydrogen atoms in hydrogen gas." W&M ScholarWorks, 1990. https://scholarworks.wm.edu/etd/1539623790.
Full textAbstract:
This experiment measured the time distribution of muonic hydrogen atoms which were formed when negative muons were brought to rest in H{dollar}\sb2{dollar} gas, containing Au target foils, at five pressures (750 mbar, 375 mbar, 188 mbar, 94 mbar and 47 mbar at 4.6 mm foil spacing). A Monte Carlo method is applied for deducing the initial velocity distribution, and preliminary results are obtained. The initial velocity distribution of {dollar}\mu{dollar}H atoms is reasonably well described as a 'Maxwellian' velocity distribution with a mean energy E = 3.4 eV. The corresponding muon mean capture energy is obtained: E{dollar}\sb{lcub}\rm c{rcub}{dollar} {dollar}\approx{dollar} 34 eV for {dollar}\mu{dollar}H atom and E{dollar}\sb{lcub}\rm c{rcub}{dollar} {dollar}\approx{dollar} 68 eV for {dollar}\mu{dollar}H{dollar}\sb2{dollar} molecules. We also find the negative muon capture energy distribution is exponential.;In addition, a significant improvement of the negative muon mean life {dollar}\tau{dollar} in Au is abtained in this experiment.: {dollar}\tau\sb{lcub}\rm Au{rcub}{dollar} = 69.716 {dollar}\pm{dollar} 0.144 ns. The "full decay curve fitting method" which we use in this experiment has an advantage over the previous method in three aspects: (1) We have measured the mean life and determined the time resolution {dollar}\sigma{dollar}(E) of a detector at a particular energy level; (2) We have determined the effective zero time of the decay curve; (3) We have provided a possible way to measure the mean life {dollar}\tau{dollar} when {dollar}\tau{dollar} is less than the time resolution {dollar}\sigma{dollar}(E) of the detector ({dollar}\tau{dollar} {dollar}<{dollar} {dollar}\sigma{dollar}(E)).
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Filosa, Christopher. "Tomographie muonique : du développement de détecteurs à la résolution du problème inverse." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS506.
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Cette thèse porte sur le développement des détecteurs gazeux Micromegas pour la tomographie muonique. Cette technique permet d’utiliser les muons cosmiques issus des interactions entre des rayons cosmiques et l’atmosphère, afin d’imager des objets de grandes dimensions et de grande opacité tels que des bâtiments, des dalles de béton, des volcans ou encore des pyramides comme la pyramide de Khéops en Égypte. En étudiant l’atténuation du flux de muons à travers un objet, nous pouvons obtenir des informations sur sa structure interne. Pour imager de telles structures et détecter les muons qui les traversent, des télescopes muoniques utilisant des détecteurs Micromegas sont utilisés. Les travaux effectués pendant cette thèse ont eu pour but d'améliorer les performances en résolution spatiale et en gaz de ces détecteurs.Un des objectifs de cette thèse a été d’imager une dalle de béton de 2 m de longueur, 1 m de largeur et 50 cm d’épaisseur. Dans un premier temps, nous avons réalisé une étude sur la détection de défauts dans cette dalle. Grâce à un algorithme développé pendant cette thèse, un trou de 15 cm de côté peut être détecté avec un niveau de confiance de 98% à partir de 4h de prise de données. Par la suite, nous avons réalisé une étude de faisabilité en deux dimensions, dans le plan de la longueur de la dalle, afin de pouvoir reconstruire la carte de densité de la dalle de béton. Pour ce faire, nous avons dû résoudre ce qu'on appelle le problème inverse : l’estimation des paramètres d’un objet en fonction des données collectées. Ici la densité de la dalle de béton joue le rôle de paramètres à estimer et le flux de muons ayant traversés la dalle et collectés par nos détecteurs celui de données. Après analyses des différentes systématiques du problème, nous pouvons reconstruire la densité d’une dalle de béton, avec une résolution en épaisseur de 125 mm et une résolution en longueur de 437.5 mm, avec une erreur relative maximale de 12%This thesis presents the development of Micromegas gaseous detectors for muon tomography. This technique use cosmic muons, resulting from interactions between cosmic rays and the atmosphere to image objects of large dimensions and opacity such as buildings, concrete slabs, volcanoes or pyramids such as the Khufu's pyramid in Egypt. By studying the attenuation of the muon flux through objects, we can access their internal structure. To image such structures and detect muons passing through them, muon telescopes using Micromegas detectors are used. Many efforts have been developed during this thesis to improve the spatial resolution and gas performance of the latter.One of the main goal of this thesis is to image a concrete slab, which dimensions were 2000 mm x 1000 mm x 500 mm. Firstly, a study on the detection of defects in this slab was carried out. Thanks to an algorithm developed during this thesis, a 15cm wide default can be detected with a 98% confidence level from 4h of data collection. Subsequently, a two-dimensional feasibility study, in the plan of the slab length, was carried out in order to reconstruct the density map of the concrete slab. To do this, we need to solve what is commonly referred to as the inverse problem: estimating the parameters of an object based on the data collected. Here the density of the concrete slab will play the role of parameters to be estimated and the flux of muons that have passed through the slab and collected by our detectors will play the role of data. After analysing the different systematic problem analyses, we can reconstruct the density of a concrete slab, with a thickness resolution of 125mm and a length resolution of 437.5mm, with a maximum relative error of 12%
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Prado, Raul Ribeiro. "Experimental studies of the muonic component of extensive air showers." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-21062018-150629/.
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Ultra-High Energy Cosmic Rays (UHECR) can only be measured by the detection of Extensive Air Showers (EAS) created by the interaction of the cosmic ray particle with an atmospheric nuclei. The inference of some of the properties of UHECR, like their mass composition, is only possible by the comparison of measurements of EAS observables to predictions from Monte Carlo simulations. The most important source of uncertainties on the description of EAS by the simulations is the modeling of hadronic interactions. For many years it has been known that the hadronic interaction models fail on predicting the EAS observables related to their muonic component. The most evident manifestation of that is called muon deficit problem due to the fact that the number of muons in EAS with energies above 1018 eV predicted by simulations is smaller than the observed ones. The aim of this thesis is to approach this problem in three distinct fronts. First, a method is developed to interpret measurements of number of muons in terms of cosmic rays composition in despite of the muon deficit problem. Second, an EAS observable which is sensitive to the muon energy spectrum at ground and, consequently, can be used to constrain hadronic interaction models is proposed and tested. Third and final, the muon production in air showers is studied through measurements of hadron production spectra in pion-carbon interactions.Raios Cósmicos Ultra Energéticos (Ultra-High Energy Cosmic Rays, UHECR) somente podem ser medidos através da detecção dos Chuveiros Atmosféricos Extensos (Extensive Air Showers, EAS) criados pela interação do raio cósmico primário com núcleos atmoféricos. A inferência de algumas propriedados dos UHECRs, como a composição de massa, é possível somente através da comparação entre medidas de observáveis dos EASs com predições geradas por simulações de Monte Carlo. A fonte de incerteza mais importante na descrição de EAS por simulações é a modelagem das interações hadrônicas. Por muitos anos é sabido que os modelos de interação hadrônica falham na predição de observáveis dos EASs relacionados a sua componente muônica. A manifestação mais evidente disso é chamada problema do déficit de múons devido ao fato que o número de múons em chuveiros com energias acima de 1018 eV predito por simulações é menor que os observados. O objetivo desta tese é abordar este problema através de três frentes. Primeiramente, um método é desenvolvido para interpretar as medidas do número de múons em termos de composição de raios cósmicos considerando o problema do déficit de múons. Segundo, a proposta e o teste de um observável que é sensível ao espectro de energia dos múons na superfície e, consequentemente, pode ser usado para discriminar entre os modelos de interação hadrônica. Por último, a produção de múons em chuveiros é estudada através de medidas do espectro de produção de hádrons em interações do tipo píon-carbono.
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Bouteille, Simon. "Développement et applications de détecteurs gazeux à micro-pistes pour la tomographie muonique." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS210/document.
Full textAbstract:
Cette thèse décrit les premiers essais de tomographie muonique par absorption et par déviation en utilisant des détecteurs Micromegas à haute granularité. Cette technique d'imagerie utilisant les rayons cosmiques gratuits, sans dangers et disponibles partout a démontré sa capacité à imager des objets de tailles variées. Afin de construire des outils compacts, précis, et portables, utiliser une voie d'électronique pour lire chaque motif de lecture est impossible. Pour éviter ce problème, des détecteurs multiplexés ont été conçus, testés et mis en situation dans différentes conditions. Il a été tiré parti des dernières améliorations concernant le détecteur Micromegas telles que le multiplexage génétique ou la lecture 2D par pistes sous une couche résistive. Les prototypes qui ont été fabriqués ont atteint une résolution de 300µm sur une surface d'un quart de mètre carré en ne nécessitant que 61 voies d'électronique. Grâce à ces détecteurs, des campagnes de prise de données ont été faites, à la fois dans l'environnement semi-contrôlé du centre CEA de Saclay et sur le plateau de Gizeh en Egypte. Ces deux campagnes ont permis d'imager avec succès le château d'eau du CEA Saclay ainsi que la pyramide de Khéops et ce malgré les conditions extrêmes que les télescopes à muon ont endurées. Des variations de température de plusieurs dizaines de Kelvin ont été enregistrées alors que l'acquisition de données se déroulait de manière stable, c'est-à-dire que les variations du gain n'impactaient pas le système d'auto déclenchement. Cette stabilité a été rendue possible grâce à un ajustement des hautes tensions vis à vis des conditions environnementales. Cela constitue la première mondiale concernant le fonctionnement d'un dispositif de reconstruction de trace à base de Micromégas en extérieur. En parallèle des expériences de muographie par déviation ont été menées. Un dispositif imageant des objets de petite taille est capable de distinguer divers matériaux sur une échelle de temps de l'ordre d'une journée. Une plus grande installation a permis d'imager un conteneur entier. La résolution du problème inverse a été faite en utilisant à la fois l'algorithme simple dit du PoCA ainsi que celui de maximisation de vraisemblance proposé par Schultz et son équipeThis thesis describes the first attempts to perform both absorption and scattering muon tomography using high granularity Micromegas detectors. This imaging technique using the free, available and harmless cosmic ray muons radiation shows great possibilities to study various sized objects. In order to make compact and precise portable devices, using one channel of electronics per readout pattern is not possible. To avoid this problem multiplexed detectors have been designed, extensively tested and used in numerous conditions. Latest developments in Micromegas design have been used such as the genetic multiplexing and the 2D strip readout using a resistive layer. The prototypes made were able to achieve a 300µm resolution at the scale of 50cm while using only 61 channels of electronics. Using these detectors, muography data taking campaigns have been performed both in the semi-controlled environment of the Saclay site of CEA and in the wild of the Giza plateau in Egypt. These two campaigns succeeded in imaging the CEA Saclay water tower and the Khufu's pyramid despite the extreme conditions endured by the Micromegas muon telescopes. Large temperature variations of a few tens of Kelvin have been recorded together with a stable operation i.e. an even gain ensuring a steady self triggering system. This stability was achieved using high voltage variations with respect to the environmental conditions. Together with this very first worldwide operation of a Micromegas-based tracker outside a laboratory, scattering muographies have also been done. A small setup imaging handheld objects performed well in separating various materials in time scales of the order of the day while a bigger 1m² setup allowing the scan of a full container was successfully operated. The inversion of the ill-posed problem of the muon scattering was performed using the crude PoCA method and the maximum likelihood one described by Schultz et al
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Lewis, David M. "A theoretical study of the autoionization of the muonic quasi-molecule." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291971.
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Ziat, Djamel. "Étude de systèmes magnétiques par rotations de spins de muons et chaleur spécifique." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10159.
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Ce manuscrit décrit les projets de recherche qui ont porté sur l’étude de deux familles
de matériaux magnétiques frustrés. La première partie traite de la réalisation d’expériences
de chaleur spécifique sur le pyrochlore Sm2Ti2O7. Ces expériences ont eu lieu dans un
réfrigérateur à dilution 3He-4He, à l’Université de Sherbrooke, dont le fonctionnement
est décrit en amont. Ces expériences ont notamment permis l’étude de ce matériau aux
températures inédites de 160 mK, où une transition magnétique du second ordre a été
mise en évidence. La deuxième partie de ce mémoire porte sur l’étude des perovskites 6H,
Ba3MRu2O9, à l’aide de la technique de rotation de spins de muons (mSR). Un chapitre de ce
manuscrit est consacré à la description de cette technique, et les expériences ont eu lieu au
centre de recherche TRIUMF, à Vancouver. Cette technique consiste à sonder le magnétisme
local des matériaux placés dans un cryostat, afin de pouvoir remonter à la configuration
magnétique de leur état fondamental. Contrairement à laRMN, la techinque de mSR présente
le grand avantage de pouvoir sonder des matériaux avec des moments nucléaires nuls, et
des expériences pouvant être réalisées sans l’application de champ externe, garantissant la
conservation de l’état fondamental des matériaux étudiés. Nos expériences ont été réalisées
sur quatre échantillons, avec M = La, Lu, In et Y, et bien que de précédentes études par
diffraction de neutrons n’ont révélé aucune ordre magnétique à longue portée dans deux de
ces composés, nos expériences ont pu mettre en évidence l’existence d’un état fondamental
avec un faible moment magnétique. Enfin, l’importance des résultats de ces deux projets
réside dans le fait d’avoir observé un état fondamental ordonné même si ces états n’ont pas
pu être sondé à l’aide d’autres techniques, du fait des faibles moments magnétiques des
matériaux étudiés.
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Diepold, Marc [Verfasser], and Theodor W. [Akademischer Betreuer] Hänsch. "The Lamb shift in muonic Helium ions / Marc Diepold ; Betreuer: Theodor W. Hänsch." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2015. http://d-nb.info/1122435770/34.
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Stocki, Trevor J. "Measurement of muonic hyperfine transition rates and muon capture yields in light nuclei." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0024/NQ38983.pdf.
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Fujiwara, Makoto C. "Time-of-flight studies of muon catalyzed fusion with a muonic tritium beam." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0008/NQ38888.pdf.
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Williams, Grayson L. "W Boson Charge Asymmetry in the Muonic Decay Channel at the CMS Experiment." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1321594806.
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Zhu, Jianhui. "W boson measurement in the muonic decay channel at forward rapidity with ALICE." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0014/document.
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La haute densité d’énergie atteinte au Large Hadron Collider (LHC) au CERN permet une production abondante de sondes dures, telles que quarkonia, jets à haute impulsion transverse (pT) et bosons vecteurs (W, Z), qui sont produits lors de la collision partonique initiale. Les bosons vecteur se désintègrent avant la formation du Plasma de Quark et de Gluons (PQG), une phase déconfinée de la matière, qui peut être produite lors de collisions d’ions lourds ultra-relativistes. Les leptons issus de la désintégration des bosons électrofaibles ne sont pas sensibles à l’interaction forte avec le PQG. Pour ces raisons les bosons électrofaibles fournissent une référence pour l’étude des modifications induites par le milieu sur les sondes colorées.La production de bosons W en collisions pp à √s=8 TeV et en collisions p-Pb à √sNN=5.02 TeV est mesurée dans le canal de désintégration muonique au LHC avec le détecteur ALICE. En collision pp, la gamme de rapidité couverte par la mesure est -4cms<-2.5. En collision p-Pb, la différence d’énergie entre le proton et l’ ion plomb donne lieu à un décalage en rapidité. En inversant la direction des faisceaux, il est possible de couvrir les régions de rapidité -4.46cms<-2.96 et 2.03cms<3.53. Les résultats présentés dans cette thèse consistent dans la mesure de la section efficace de la production de muons avec pT>10GeV/c issus de la désintégration des bosons W+ et W-. La mesure de l’asymétrie de charge, définie comme la différence des taux de production des muons positifs et négatifs divisée par leur somme, est également effectuée. Les résultats sont comparés avec des calculs théoriques obtenus avec ou sans tenir compte des modifications des fonctions de distribution partonique dans les noyaux. La production du boson W est aussi étudiée en fonction de la centralité des collisions : nous observons que, dans les erreurs expérimentales, la section efficace des muons issus de la désintégration du boson W est proportionnelle aux nombre de collisions binaires entre les nucléonsThe high collision energies available at the LHC allow for an abundant production of hard probes, such as quarkonia, high-pT jets and vector bosons (W, Z), which are produced in initial hard parton scattering processes. The latter decay before the formation of the Quark-Gluon Plasma (QGP), which is a deconfined phase of QCD matter produced in high-energy heavy-ion collisions. Their leptonic decay products do not interact strongly with the QGP. Thus electroweak bosons introduce a way for benchmarking in-medium modifications to coloured probes. The production of W-boson in pp collisions at √s=8 TeV and p-Pb collisions at √sNN=5.02 TeV are measured via the muonic decay channel at the LHC with the ALICE detector. In pp collisions the rapidity covered by the measurement is -4cms<-2.5. In p-Pb collisions, on the other hand, the different energies of the proton and lead ion give rise to a rapidity shift. By exchanging the direction of the beams, it is possible to cover the rapidity ranges -4.46cms<-2.96 and 2.03cms<3.53. The production cross section and charge asymmetry of muons from W-boson decays with pμT>10 GeV/c are determined. The results are compared to theoretical calculations both with and without including the nPDFs. The W-boson production is also studied as a function of the collision centrality: the cross section of muons from W-boson decays is found to scale with the average number of binary nucleon-nucleon collisions with uncertainties
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Senosi, Kgotlaesele Johnson. "Production of W± bosons in the semi-muonic channel at forward rapidity in ALICE." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/6649.
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Facchini, Leonardo. "Misure di tempo di volo di muoni con l'elettronica dell'esperimento FOOT." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19396/.
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L'esperimento FOOT (FragmentatiOn On Target) nasce con lo scopo di misurare la sezione d'urto differenziale per processi di frammentazione nucleare per potere descrivere
con precisione l'interazione tra i fasci di ioni impiegati in adroterapia e i tessuti del paziente. Una misura necessaria per calcolare le sezioni d'urto e il tempo di volo dei frammenti. In laboratorio è stato ricreato un setup sperimentale attraverso l'utilizzo di tre scintillatori e del sistema di acquisizione dell'esperimento FOOT. Le particelle rivelate sono muoni di origine cosmica. Il tempo di volo dei muoni è ottenuto tramite un
fit delle distribuzioni combinando le misure ottenute a diverse angolazioni. Utilizzando questo apparato è stato possibile effettuare misure di tempo di volo e di flusso di muoni cosmici.
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Guerin, F. "Sonde muonique et instrumentation associée pour l'étude du plasma de quarks et de gluons dans l'expérience ALICE." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00132781.
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ALICE est le détecteur du LHC dédié à l'étude des collisions d'ions lourds ultra-relativistes. Le principal objectif de cette expérience est la mise en évidence et l'étude d'une nouvelle phase de la matière nucléaire prédite par la théorie de la chromodynamique quantique (QCD) : le Plasma de Quarks et de Gluons (PQG). Une des signatures possibles est la suppression des taux de production des quarkonia par écrantage de couleur dans les collisions d'ions lourds, dans lesquelles la formation d'un plasma est attendue. Le spectromètre à muons permettra de mesurer les taux de production des quarkonia (J/Psi, Upsilon) dans les collisions d'ions lourds via leur canal de désintégration dimuonique. Un système de déclenchement rapide, associé au spectromètre à muons, est chargé de sélectionner les événements contenant au minimum un muon ou un dimuon à l'aide d'un algorithme de recherche de traces. L'étude des performances du système de déclenchement du spectromètre à muons, réalisée à l'aide de simulations Monte-Carlo, sera présentée dans ce mémoire en mettant l'accent sur l'efficacité et la fréquence de déclenchement du système dans le cas des collisions Pb-Pb et Ar-Ar. Nous présenterons également la reconstruction du spectre en masse des dimuons de signes opposé avec le spectromètre à muons d'ALICE. A partir de ce spectre, les taux de production des états Upsilon seront extraits pour un mois de collisions Pb-Pb au LHC et pour diverses tranches en centralité.
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Tran, Ngoc Tiem. "Recherche des oscillations de neutrinos par apparition du τ avec désintégration muonique du vτ dans l'expérience OPERA." Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00534753.
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La physique des oscillations de neutrinos occupe une place majeure dans les études s'intéressant à cetteparticule. Le mécanisme des oscillations, basé sur un changement d'état de saveur d'un neutrino durant sapropagation, permet d'élucider les déficits observés de neutrinos solaires et atmosphériques et apporte des indicationsintéressantes de physique au delà du Modèle Standard par l'étude des angles de mélanges et du schéma de masse desneutrinos.OPERA est un détecteur hybride combinant à la fois latechnique d'une détection électronique en temps réel et la technique de la chambre à brouillard à émulsion ou ECC(EmulsionCloud Chamber). Le détecteur ECC est un détecteur massif (cible) composé de 150000 briques dontchacune est constituée de feuilles de plombs, utilisées comme cible, alternées avec des émulsions nucléaires dont laprécision de reconstruction des traces est de l'ordre du micron. Le détecteur comprend également deux spectromètresavec des plaques de fer magnétisé de 5 cm d'épaisseur alternées avec les détecteurs RPC (Resistive Plate Chamber)associés à six ensembles de drift tubes (PT) pour la mesure de la charge et de l'impulsion du muon, et un plan de vetoservant à la rejection des particules extérieures à la cible.
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Tran, Ngoc Tiem. "Recherche des oscillations de neutrinos par apparition du τ avec désintégration muonique du vτ dans l’expérience OPERA." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10203/document.
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La physique des oscillations de neutrinos occupe une place majeure dans les études s’intéressant à cetteparticule. Le mécanisme des oscillations, basé sur un changement d’état de saveur d’un neutrino durant sapropagation, permet d’élucider les déficits observés de neutrinos solaires et atmosphériques et apporte des indicationsintéressantes de physique au delà du Modèle Standard par l'étude des angles de mélanges et du schéma de masse desneutrinos.OPERA est un détecteur hybride combinant à la fois latechnique d'une détection électronique en temps réel et la technique de la chambre à brouillard à émulsion ou ECC(EmulsionCloud Chamber). Le détecteur ECC est un détecteur massif (cible) composé de 150000 briques dontchacune est constituée de feuilles de plombs, utilisées comme cible, alternées avec des émulsions nucléaires dont laprécision de reconstruction des traces est de l'ordre du micron. Le détecteur comprend également deux spectromètresavec des plaques de fer magnétisé de 5 cm d'épaisseur alternées avec les détecteurs RPC (Resistive Plate Chamber)associés à six ensembles de drift tubes (PT) pour la mesure de la charge et de l'impulsion du muon, et un plan de vetoservant à la rejection des particules extérieures à la cibleThe physics of neutrino oscillations plays a major role in studies concerned with cetteparticule. The mechanism of oscillations, based on a change of state of a neutrino flavor during sapropagation, elucidates the deficits observed solar and atmospheric neutrinos and provides indicationsintéressantes of physics beyond the Standard Model by studying the angles mixtures and mass desneutrinos.OPERA scheme is a hybrid sensor combining both latechnique an electronic real-time detection technology and the cloud chamber emulsion or ECC (EmulsionCloud chamber). The ECC is a solid detector detector (target) consisting of bricks dontchacune 150000 consists of sheets of lead, used as a target, with alternate nuclear emulsion whose traces laprécision reconstruction is of the order of one micron. The detector also includes two spectromètresavec magnetized iron plates 5 cm alternating with RPC (Resistive Plate Chamber) detectors associated with six sets of drift tubes (PT) to measure the charge and momentum of the muon thickness and plan vetoservant the rejection of foreign particles to the target
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Guérin, Fabien. "Sonde muonique et instrumentation associée pour l'étude du plasma de quarks et de gluons dans l'expérience ALICE." Clermont-Ferrand 2, 2006. http://195.221.120.247/simclient/consultation/binaries/stream.asp?INSTANCE=UCFRSIM&eidmpa=DOCUMENTS_THESES_215.
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ALICE est le détecteur du LHC dédié à l'étude des collisions d'ions lourds ultra-relativistes. Le principal objectif de cette expérience est l'étude d'une nouvelle phase de la matière nucléaire : le plasma de Quarks et de Gluons (PQG). Le spectromètre à muons d'ALICE permettra de mesurer les taux de production des quarkonia (J/psi, signe) dans les collisions d'ions lourds via leur canal de désintégration dimuonique. Le système de déclenchement rapide du spectromètre à muons est chargé de sélectionner les événements contenant au minimum un muon ou un dimuon. L'étude des performances du système de déclenchement du spectromètre à muons, réalisée à l'aide de simulations Monte-Carlo, sera présenté dans ce mémoire. Nous présenterons également la reconstruction du spectre en masse des dimuons de signes opposés avec le spectromètre à muons d'ALICE et l'extraction des taux de production des états Upsilon pour un mois de collisions Pb-Pb au LHC et pour diverses tranches en centralité
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Freund, Kai Lorenz [Verfasser], and Peter [Akademischer Betreuer] Grabmayr. "Muonic Background in the GERDA Neutrinoless Double-Beta Experiment / Kai Lorenz Freund ; Betreuer: Peter Grabmayr." Tübingen : Universitätsbibliothek Tübingen, 2014. http://d-nb.info/1163237019/34.
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Barbano, Eleonora. "Studio della risoluzione in impulso dei muoni nel Near Detector di DUNE." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19392/.
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Lo studio delle proprietà del neutrino ha conseguito notevoli risultati negli ultimi decenni, tuttavia esistono domande alle quali, al momento, non si è in grado di dare una risposta. Alcuni quesiti aperti riguardano la violazione di CP nel settore leptonico e la gerarchia di massa.
L'esperimento DUNE sarà un progetto internazionale finalizzato allo studio delle oscillazioni di neutrino su un fascio di 1300 km dal Fermilab al South Dakota, con l'obiettivo di migliorare le nostre conoscenze sui processi che coinvolgono queste particelle.
L'oggetto di questa tesi è stato lo studio delle prestazioni di un rivelatore, proposto come Near Detector nell'esperimento DUNE, che riutilizzi il magnete e il calorimetro del rivelatore KLOE, impiegato fino al 2019 presso i laboratori di Frascati.
In particolare è stata condotta un'analisi utilizzando dati simulati di interazioni di neutrini muonici nel rivelatore. Sono mostrati e discussi, infine, i risultati ottenuti sulla risoluzione in impulso dei muoni prodotti.
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Kirnosov, Nikita. "Advances in Modeling of Physical Systems Using Explicitly Correlated Gaussian Functions." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/594645.
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In this dissertation recent advances in modeling various atomic and molecular systems with quantum mechanical calculations employing explicitly correlated Gaussian functions are presented. The author has utilized multiple approaches and considered a number of approximations to develop optimal calculation frameworks. Electronic and muonic molecules and atoms have been considered. A number of unique calculations have been performed and some novel and interesting results, including high accuracy description of the charge asymmetry in the heteronuclear systems and lifetimes of rotationless vibrational levels of diatomic molecules, have been generated.
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Sartini, Simone. "Misure di tempo di volo di muoni cosmici con strumentazione disponibile in laboratorio." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17633/.
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La misura del tempo di volo (TOF) delle particelle cariche da sempre gioca un ruolo importante in fisica nucleare e subnucleare, in particolare per l'identificazione di particelle a lunga vita media; l'affinarsi delle tecniche sperimentali e il conseguente miglioramento della precisione delle misure ha portato nuovo interesse alle misure di TOF. In questa tesi è presentata una misura del tempo di volo dei muoni della radiazione cosmica, eseguita con la strumentazione disponibile in laboratorio. L'accento non è posto sulla ricerca del miglior risultato possibile date le tecniche di rivelazione e l'elettronica disponibili oggigiorno, che avrebbe richiesto l'impiego di rivelatori più performanti, quanto piuttosto sull'analisi delle sistematiche legate alla misura stessa, così che quanto appreso abbia validità generale. Le diverse fasi della misura, che comprendono la scelta dei rivelatori, la loro disposizione, il sistema di raccolta dei dati e la loro analisi, si presentano infatti in qualunque esperimento.
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Pacelli, Francesco. "Studio di un luminometro basato sui Drift Tubes di CMS." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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In questo lavoro di tesi si verifica la possibilità di utilizzare i conteggi del trigger di muoni basato sui Drift Tubes del rivelatore CMS per ricavare la luminosità del fascio. Si valutano tre algoritmi di trigger utilizzando dati raccolti durante il run protone-protone del 2018. Sono stati analizzati sia run in cui il rivelatore era in condizioni ideali, sia run in cui alcune parti non erano funzionanti, al fine di valutare la stabilità del luminometro realizzato. Quest’ultimo risulta stabile nei run considerati, tanto da fornire una stima della luminosità confrontabile o addirittura migliore di quella misurata online
durante la presa dati.
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Mollica, Davide. "Simulazioni Geant4 di muografie vulcaniche con telescopi Cherenkov." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/17093/.
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Negli ultimi anni sono stati fatti grandi passi in avanti nel campo della muografia vulcanica. Questa tecnica sfrutta l'elevato potere penetrante dei muoni prodotti dall'interazione dei raggi cosmici primari con l'atmosfera terrestre per ricavare informazioni sulla struttura interna degli edifici vulcanici. La muografia permette di monitorare variazioni di densità utili a determinare lo stato di attività di un vulcano e ridurre il rischio associato. La principale difficoltà nell'applicazione della tecnica è data dal rumore di fondo di cui soffrono i rivelatori comunemente utilizzati. Per migliorare il rapporto segnale-rumore sono necessarie diverse lastre schermanti di piombo e ferro che rendono il rivelatore costoso e difficile da trasportare.
Per far fronte a questi problemi, recentemente è stato proposto l'utilizzo di telescopi Cherenkov dedicati alla muografia. Questi non soffrono del rumore di fondo degli altri rivelatori e possono essere progettati con una struttura di supporto leggera e facilmente trasportabile.
Questo lavoro di tesi si propone come uno studio preliminare di fattibilità necessario per lo sviluppo dell'ottica e dell'elettronica di un telescopio Cherenkov per la muografia vulcanica. A tal fine, ho sviluppato un software di simulazione basato su Geant4, un framework dedicato all'interazione delle particelle con la materia, che simula il passaggio dei muoni atmosferici attraverso un modello di edificio vulcanico e lo strato di atmosfera che lo separa dal telescopio, e la produzione di fotoni Cherenkov. Per studiare la rivelazione di questi, ho utilizzato il simulatore del prototipo di telescopio Cherenkov di piccola dimensione ASTRI SST-2M progettato per CTA e ho implementato un metodo per ricostruire la direzione dei muoni a partire dalle immagini ottenute con il simulatore. Il modello vulcanico utilizzato si basa sulle caratteristiche del Cratere Sud-Est del Monte Etna, il quale è visibile dal sito di installazione di ASTRI.
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Agostini, Federica. "Caratterizzazione e calibrazione dei fotomoltiplicatori del sistema di veto di muoni per l'esperimento xenon1t." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5955/.
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Alcune osservazioni sperimentali portano ad affermare che la maggior parte della massa dell'universo è costituita da un tipo di materia definita oscura, cioè materia che interagisce solo gravitazionalmente e debolmente. I candidati più promettenti sono tipicamente identificati con le WIMP (Weakly Interacting Massive Particle).
L'esperimento XENON1T per la rivelazione di materia oscura, in fase di costruzione nei Laboratori Nazionali del Gran Sasso, sfrutta uno spessore di 1.4 km di roccia schermante. Il rivelatore è una Time Projection Chamber contenente circa 2 tonnellate di xeno e avrà sensibilità per sezioni d’urto WIMP-nucleo spin-indipendent pari a circa 2x10-47 cm2 (per WIMP di massa 50 GeV/c2), due ordini di grandezza al di sotto degli attuali limiti. Per raggiungere tale sensibilità la TPC sarà inserita in una tank cilindrica riempita di acqua ultrapura, che fungerà sia da schermo passivo contro la radiazione esterna (gamma e neutroni di bassa energia), sia da veto per i muoni cosmici. I muoni possono infatti produrre neutroni di energia tale da raggiungere la TPC e simulare segnali tipici delle WIMP. Essi sono identificati per via della radiazione Cherenkov, emessa in seguito al loro passaggio in acqua, rivelata per mezzo di 84 fotomoltiplicatori (PMT) 8'' Hamamatsu R5912ASSY HQE.
Lo studio delle prestazioni e delle caratteristiche dei PMT utilizzati nel sistema di veto di muoni sono lo scopo di questo lavoro di tesi. In particolare è stato preparato un opportuno setup per i test dei fotomoltiplicatori e sono state effettuate misure di guadagno, dark rate ed afterpulse. In una prima fase sono stati testati in aria 50 PMT presso la Sezione INFN di Bologna, nel periodo compreso tra Novembre 2012 e Marzo 2013 ed in una seconda fase sono stati testati in acqua 90 PMT presso i Laboratori Nazionali del Gran Sasso, nel periodo compreso tra Aprile e Settembre 2013.
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Krauth, Julian [Verfasser], and Theodor W. [Akademischer Betreuer] Hänsch. "The Lamb shift of the muonic helium-3 ion and the helion charge radius / Julian Krauth ; Betreuer: Theodor W. Hänsch." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1132061083/34.
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