Dissertations / Theses: 'High-energy nuclear physic'

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Szabo, Anthony Paul. "High energy emissions for astrophysical objects." Title page, contents and abstract only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phs996.pdf.

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Frederiksen, Joorgen Segerlund. "Theoretical studies in high energy physics and atmospheric dynamics /." Title page, introduction and contents only, 1987. http://web4.library.adelaide.edu.au/theses/09SD/09sdf852.pdf.

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Kvasnikova, Ioulia. "Mesonic sources of dileptons in ultrarelativistic nuclear collisions." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37753.

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In this work thermal dilepton production from a hot medium created in heavy ion collision is studied. Using an effective Lagrangian technique for particle decays and annihilations, a complete method for calculation of the lepton pair production rate is developed. The importance of axial vector meson contributions to the dilepton spectrum is analyzed. Different effective Lagrangians for the a1rhopi interaction are considered, and a new form of b1o(&phis;)pi effective Lagrangian is introduced.
A systematic study of light meson contributions is performed. The most significant decay and reaction contributions are calculated and summed for low and intermediate invariant mass dileptons. The calculated dilepton rate is compared to that obtained using spectral functions extracted from data, and it is shown that the chosen set of mesonic reactions and decays accounts for all significant contributions to the thermal dilepton emission.
A hydrodynamic approach to the space-time evolution of the hot medium formed as a result of a central heavy ion collision at ultra-relativistic energies is considered. A theoretical curve of intermediate invariant mass dilepton spectrum is computed and compared to the NA50 data from central Pb(158 AGeV)+Pb collisions. Experimental acceptance cuts are accounted for. Drell-Yan processes are considered as well. We find that our thermal dileptons account for the intermediate mass excess observed by the NA50 Collaboration. We see no need to invoke charm enhancement. Predictions for the future experiments at RHIC and are made.

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Eggers, Hans Christoph. "Intermittency, moments and correlations in distributions of particles created in high-energy collisions." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185422.

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Intermittency, as introduced into multiparticle production by Bialas and Peschanski, has become a fruitful and rapidly growing industry. The original concept of intermittency in the form of the Alpha model is discussed in detail and suggestions for extensions are made. We analyze the factorial moments measured by different experimental collaborations in terms of their nontrivial many-particle correlations, the cumulants. A large fraction of measured moments is shown to originate in two-particle correlations. The validity of the Linked Pair ansatz is tested and found to be acceptable to fourth order for hadronic collisions but uncertain for nuclear collisions. A cumulant decomposition for bin-bin correlations is derived, and a general formalism is developed for treating correlations of particle distributions consisting of several distinct populations, such as particles of different charge.

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Bourque, François-Alex. "Electromagnetic signature of early gluon populations in ultrarelativistic nuclear collisions." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=78326.

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We first present a brief overview of the quark-gluon plasma (QGP) and its possible production in a heavy ion collision. Equilibrium quantum field theory is then outlined as a tool to study QGP. With this, we investigate the consequence of a finite charge density plasma through the breaking of Furry's theorem. In particular, we calculate the dilepton differential production rate for one of the simplest medium-induced processes: 2g → ll¯. We show that this effect is sub-dominant to the leading tree-level qq¯ → ll¯.

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Wang, Yongjiang. "Aspects of pion propagation in hot and dense nuclear matter." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60494.

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Some important aspects of pion propagation in hot and dense nuclear matter are investigated by considering the dominant p-wave pion nucleon interaction including the $ Delta$-isobar channel. We find that for zero temperature nuclear mater, the static approximation in the computation of the pion branch dispersion relation is not adequate in general. In the finite temperature nuclear matter up to T = 50MeV, the pion propagation does not change much comparing to that in the zero temperature medium, but the pion absorption through the first order pion-nucleon interaction, on the other hand, increases significantly as the temperature goes up. We also give a formula to determine the critical nuclear matter density $ rho sb{c}$ and when $ rho > rho sb{c}$ is satisfied, a minimum exists in the corresponding pion branch.

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Abrahamyan, Tigran. "High energy three-body breakup of three-nucleon systems." FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/1107.

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The main goal of this dissertation was to study two- and three-nucleon Short Range Correlations (SRCs) in high energy three-body breakup of 3He nucleus in 3He(e, e'NN)N reaction. SRCs are characterized by quantum fluctuations in nuclei during which constituent nucleons partially overlap with each other. A theoretical framework is developed within the Generalized Eikonal Approximation (GEA) which upgrades existing medium-energy methods that are inapplicable for high momentum and energy transfer reactions. High momentum and energy transfer is required to provide sufficient resolution for probing SRCs. GEA is a covariant theory which is formulated through the effective Feynman diagrammatic rules. It allows self-consistent calculation of single and double re-scatterings amplitudes which are present in three-body breakup processes. The calculations were carried out in detail and the analytical result for the differential cross section of 3He(e, e'NN)Nreaction was derived in a form applicable for programming and numerical calculations. The corresponding computer code has been developed and the results of computation were compared to the published experimental data, showing satisfactory agreement for a wide range of values of missing momenta. In addition to the high energy approximation this study exploited the exclusive nature of the process under investigation to gain more information about the SRCs. The description of the exclusive 3He(e, e'NN)N reaction has been done using the formalism of the nuclear decay function, which is a practically unexplored quantity and is related to the conventional spectral function through the integration of the phase space of the recoil nucleons. Detailed investigation showed that the decay function clearly exhibits the main features of two- and three-nucleon correlations. Four highly practical types of SRCs in 3He nucleus were discussed in great detail for different orders of the final state re-interactions using the decay function as an unique identifying tool. The overall conclusion in this dissertation suggests that the investigation of the decay function opens up a completely new venue in studies of short range nuclear properties.

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Biehl, Daniel. "Nuclear Cascades and Neutrino Production in the Sources of Ultra-High Energy Cosmic Ray Nuclei." Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/20448.

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Der Ursprung ultra-hochenergetischer kosmischer Strahlung (UHECRs) ist eine der wichtigsten offenen Fragen der Astrophysik. Gammastrahlenblitze (GRBs) galten als potentielle Quellen, da sie zu den energetischsten Ereignissen im Universum zählen. Konventionelle Szenarien sind jedoch durch Neutrinodaten stark eingeschränkt. Außerdem weisen Messungen der chemischen Zusammensetzung kosmischer Strahlen auf schwere Kerne hin, welche in zu dichten Strahlungsfeldern disintegrieren würden. Um dieses Dilemma zu umgehen deuten neue Studien auf versteckte Beschleuniger hin, welche schwer zu detektieren sind. In dieser Dissertation präsentieren wir neue Ansätze um nukleare Prozesse in astrophysikalischen Quellen effizient und selbstkonsistent zu berechnen. Wir quantifizieren diese Wechselwirkungen anhand der nuklearen Kaskade, welche die Disintegration schwerer Kerne in leichtere Fragmente beschreibt. Auch in umfassenden Modellen, wie sie in dieser Arbeit entwickelt werden, sind GRBs durch Neutrinodaten unter Druck. Dennoch zeigen wir, dass eine Population von GRBs niedriger Luminosität konsistent mit derzeitigen Messungen ist und zugleich auch das Spektrum und die Zusammensetzung kosmischer Strahlung über den Knöchel hinweg sowie Neutrinodaten beschreiben kann. Aus unserer Prozedur können wir zusätzlich weitere Quelleneigenschaften wie die baryonische Ladung oder die Ereignisrate bestimmen. Wir zeigen weiter, dass auch von schwarzen Löchern zerrissene Sterne mögliche Kandidaten eines gemeinsamen Ursprungs der gemessenen kosmischen Strahlung und PeV-Neutrinos sind. Sie können jedoch durch kosmogenische Neutrinos von LLGRBs abgegrenzt werden. Schließlich wenden wir unser Modell auf das Gravitationswellenereignis GW170817 an. Wir zeigen für verschiedene Jet-Szenarien, dass der erwartete Neutrinofluss weit unter der Sensitivität derzeitiger Instrumente liegt. Dennoch könnten verschmelzende Neutronensterne die kosmische Strahlung unterhalb des Knöchels erklären.
The origin of Ultra-High Energy Cosmic Rays (UHECRs) is still one of the most important open questions in astrophysics. Gamma-Ray Bursts (GRBs) were considered as potential sources as they are among the most energetic events known in the Universe. However, conventional GRB scenarios are strongly constrained by astrophysical neutrino data. In addition, cosmic ray composition measurements indicate the presence of heavy nuclei, which would disintegrate if the radiation fields in the source were too dense. In order to circumvent this dilemma, recent studies point towards hidden accelerators, which are intrinsically hard to detect. In this dissertation, we present novel approaches to efficiently and self-consistently calculate the nuclear processes in astrophysical sources. We quantify these interactions by means of the nuclear cascade, which describes the subsequent disintegration of heavy nuclei into lighter fragments. Even in sophisticated source-propagation models, as the ones developed in this thesis, conventional GRBs are in tension with neutrino data. However, we demonstrate that a population of low-luminosity GRBs is not only consistent with current constraints, but can even describe the UHECR spectrum and composition across the ankle as well as neutrino data simultaneously. From our fitting procedure we can further constrain certain source properties, such as the baryonic loading and the event rate. Furthermore, we show that stars disrupted by black holes are viable candidates for a simultaneous description of cosmic ray and PeV neutrino data too. However, they can be discriminated from LLGRBs by cosmogenic neutrinos. Finally, we apply our model to GW170817. We show for different jet scenarios that the expected neutrino flux is orders of magnitude below the sensitivity of current instruments. Nevertheless, binary neutron star mergers could in principle support cosmic rays below the ankle.

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Zarkadoula, Evangelia. "Modelling of high-energy radiation damage in materials relevant to nuclear and fusion energy." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8607.

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The objective through my PhD has been to investigate radiation damage effects in materials related to fusion and to safe encapsulation of nuclear waste, using Molecular Dynamics (MD) methods. Particularly, using MD, we acquire essential information about the multi-scale phenomena that take place during irradiation of materials, and gain access at length and time-scales not possible to access experimentally. Computer simulations provide information at the microscopic level, acting as a bridge to the experimental observations and giving insights into processes that take place at small time and length-scales. The increasing computer capabilities in combination with recently developed scalable codes, and the availability of realistic potentials set the stage to perform large scale simulations, approaching phenomena that take place at the atomistic and mesoscopic scale (fractions of m for the first time) in a more realistic way. High-energy radiation damage effects have not been studied previously, yet it is important to simulate and reveal information about the properties of the materials under extreme irradiation conditions. Large scale MD simulations provide a detailed description of microstructural changes. Understanding of the primary stage of damage and short term annealing (scale of tens of picoseconds) will lead to better understanding of the materials properties, best possible long-term use of the materials and, importantly, new routes of optimization of their use. Systems of interest in my research are candidate fusion reactor structural materials (iron and tungsten) and materials related to the radioactive waste management (zirconia). High-energy events require large simulation box length in order for the damage to be contained in the system. This was a limitation for previous simulations, which was recently shifted with my radiation damage MD simulations. For the first time high-energy radiation damage effects were simulated, approaching new energy and length scales, giving a more realistic view of processes related to fusion and to high-energy ion irradiation of material.

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Allport, P. P. "High energy neutrino scattering at low Q'2." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376865.

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Kvasnikova, Ioulia. "A classical molecular dynamics study of thermodynamic variables for finite nuclear systems." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24017.

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The classical molecular dynamics model is used for a study of the possible nuclear phase transition in heavy ion collisions at intermediate energies. We implemented this model through Monte Carlo techniques. Different kinds of initial configurations are considered, as well as different methods of particles propagation. In order to simulate the canonical ensemble dynamic evolution we investigate two methods of keeping the temperature constant.
We consider a system of 85 nucleons interacting through two-body nucleon-nucleon potential. The calculations are first carried out ignoring Coulomb interaction and then including it. Data on various thermodynamic quantities are obtained and the question of the existence of the phase transition is investigated.
To estimate the effect of a finite particle number on critical parameters we go to a system of 200 nucleons.

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Kabir, Al Amin. "DETERMINATION OF THE CHARGE RADII OF SEVERAL LIGHT NUCLEI FROM PRECISION, HIGH-ENERGY ELECTRON ELASTIC SCATTERING." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1448878891.

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Tripp, Robert D. "Elastic scattering of high-energy polarized protons by complex nuclei." Berkeley, Ca. : Lawrence Radiation Laboratory, 2975. http://catalog.hathitrust.org/api/volumes/oclc/549450172.html.

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Argante, Erco. "CoCa a model for parallelization of high energy physics software /." Eindhoven : Eindhoven University of Technology, 1998. http://catalog.hathitrust.org/api/volumes/oclc/41892351.html.

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McMillan, John Eric. "Nuclear instrumentation for a superheavy-element search and for cosmic-ray studies." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237079.

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Koshchii, Oleksandr. "Effects beyond the Born Approximation for the Elastic Scattering of Leptons by a Nucleon." Thesis, The George Washington University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10846809.

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Elastic lepton scattering off of a nucleon has proven to be an efficient tool to study the structure of the hadron. In particular, the spatial distributions of the nucleon's charge and magnetization can be accessed through measurements of its electric (G_E) and magnetic (G_M) form factors. These form factors can be extracted from unpolarized cross sections measurements by using the Rosenbluth separation technique. At the current level of accuracy, a determination of G_E and G_M from an analysis of elastic lepton-nucleon scattering data requires effects beyond the leading-order (Born) approximation to be taken into account.

In this work, I study higher-order QED corrections to elastic lepton-nucleon scattering. First of all, I perform a model-independent calculation of conventional charge-dependent contributions in unpolarized lepton-proton scattering without making use of ultra-relativistic approximations. Second, in a connection to the future MUSE experiment in Switzerland, I estimate helicity-flip meson exchanges that make a difference in a comparison of ultra-relativistic vs non-ultra-relativistic lepton-proton scattering. Finally, I present a model calculation of the target-normal single-spin asymmetry in elastic electron-nucleon scattering. Such an asymmetry gives us a direct tool to studies of the imaginary part of the two-photon exchange amplitude.

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Lund, Kasey Roy. "Van de Graaff based positron source production." Thesis, Washington State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3732705.

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The anti-matter counterpart to the electron, the positron, can be used for a myriad of different scientific research projects to include materials research, energy storage, and deep space flight propulsion. Currently there is a demand for large numbers of positrons to aid in these mentioned research projects. There are different methods of producing and harvesting positrons but all require radioactive sources or large facilities. Positron beams produced by relatively small accelerators are attractive because they are easily shut down, and small accelerators are readily available.

A 4MV Van de Graaff accelerator was used to induce the nuclear reaction ¹²C(d,n)¹³N in order to produce an intense beam of positrons. 13N is an isotope of nitrogen that decays with a 10 minute half life into ¹³C, a positron, and an electron neutrino. This radioactive gas is frozen onto a cryogenic freezer where it is then channeled to form an antimatter beam. The beam is then guided using axial magnetic fields into a superconducting magnet with a field strength up to 7 Tesla where it will be stored in a newly designed Micro-Penning-Malmberg trap.

Several source geometries have been experimented on and found that a maximum antimatter beam with a positron flux of greater than 0.55×10⁶ e+s^-1 was achieved. This beam was produced using a solid rare gas moderator composed of krypton. Due to geometric restrictions on this set up, only 0.1-1.0% of the antimatter was being frozen to the desired locations. Simulations and preliminary experiments suggest that a new geometry, currently under testing, will produce a beam of 107 e+s^-1 or more.

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Beaumier, Michael John. "Probing the Spin Structure of the Proton Using Polarized Proton-Proton Collisions and the Production of W Bosons." Thesis, University of California, Riverside, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10181454.

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This thesis discusses the process of extracting the longitudinal asymmetry, $A_L

{W\pm}$, describing $W\rightarrow\mu$ production in forward kinematic regimes. This asymmetry is used to constrain our understanding of the polarized parton distribution functions characterizing $\bar{u}$ and $\bar{d}$ sea quarks in the proton. This asymmetry will be used to constrain the overall contribution of the sea-quarks to the total proton spin. The asymmetry is evaluated over the pseudorapidity range of the PHENIX Muon Arms, $2.1 < |\eta|2.6$, for longitudinally polarized proton-proton collisions at 510 GeV $\sqrt{s}$. In particular, I will discuss the statistical methods used to characterize real muonic $W$ decays and the various background processes is presented, including a discussion of likelihood event selection and the Extended Unbinned Maximum Likelihood fit. These statistical methods serve estimate the yields of $W$ muonic decays, which are used to calculate the longitudinal asymmetry.

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Morejon, Leonel. "New Interaction Models of Ultra-high-energy Cosmic Rays from a Nuclear Physics Approach." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22585.

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Der Ursprung der ultrahochenergetischen kosmischen Strahlung (UHECRs) benötigt Modelle der photonuklearen kosmischen Strahlungsinteraktionen. In dieser Arbeit stelle ich Modelle vor, die drei Aspekte der Modellierung der Hochenergie-Astronuklearphysik verbessern: die Photomesonenproduktion durch Kerne der kosmischen Strahlung, die schwerer als Protonen sind, die Gammastrahlenemission von instabilen Kernen, die durch den Photodisintegrationsprozess der kosmischen Strahlung erzeugt werden, und die Simulation der extragalaktischen Ausbreitung von Kernen, die schwerer als Eisen sind (sogenannte superschwere Isotope). Das Photomesonenmodell ist das erste in der Literatur, das über das einfache Prinzip der Nukleonen-Superposition hinausgeht. Es liefert eine detailliertere Beschreibung der inelastischen Wirkungsquerschnitte und des emittierten Spektrums von Sekundärteilchen, einschließlich Isotopen und Pionen, die zu Photonen und Neutrinos führen. Die Auswirkungen des Modells werden in Simulationen von Gammastrahlenausbrüchen und Gezeitenstörungsereignissen gezeigt, und es beeinflusst signifikant die hochenergetische Neutrinoemission, die chemische Zusammensetzung und das Spektrum der emittierten UHECRs. Das zweite Modell beschreibt die Photoproduktion aus den De-Exzitationen und Zerfällen instabiler Kerne, die aus dem Photozerfall der kosmischen Strahlung in Wechselwirkung mit astrophysikalischen Photonen resultieren sollen. Ihre Wirkung wird am Photoemissionsspektrum des Kerns von Centaurus A veranschaulicht und mit ähnlichen Arbeiten verglichen, mit denen es Unstimmigkeiten gibt. Schließlich wird der Photodesintegration von UHECR überschweren Kernen diskutiert. Eine Wechselwirkungstabelle wird unter Verwendung von Querschnitten aus TALYS konstruiert, und die Wechselwirkungsraten werden im Zusammenhang mit der extragalaktischen Ausbreitung berechnet. Überschwere Kerne breiten sich in bestimmten Energiebereichen weiter aus als leichtere Kerne.
The origin of the ultra-high-energy cosmic rays (UHECRs) is still unknown. Photonuclear interactions of cosmic rays are key to understanding this problem in a multimessenger context. Nuclear physics insights are crucial in building accurate models to interpret the data that indicates UHECR can be heavier than protons. This thesis presents models that improve three aspects of high-energy astronuclear physics modelling: photomeson production by cosmic-ray nuclei heavier than protons, gamma-ray emission from unstable nuclei created by the photodisintegration of cosmic rays, and the simulation of extragalactic propagation of nuclei heavier than iron (so-called superheavy isotopes). The photomeson model is the first in the literature to go beyond the simple principle of nucleon superposition. It provides a more accurate description of the inelastic cross sections, and the emitted spectrum of secondary particles, including isotopes and pions which lead to photons and neutrinos.The model’s impact is shown in simulations of gamma-ray bursts and tidal disruption events, and it affects significantly the high-energy neutrino emission, the chemical composition and the spectrum of the emitted UHECRs. The second model describes photoproduction from de-excitations and decay of unstable nuclei, which are expected to be produced in photo-disintegration of cosmic rays interacting with astrophysical photons. Its impact is illustrated in the photo-emission from the core of the Centaurus A and compared to similar works with which is in disagreement. This supports the need for sufficiently accurate models. Lastly, the photodisintegration of UHECR superheavy nuclei is discussed. An interaction table is produced with cross sections obtained from TALYS and the interaction rates computed in the context of extragalactic propagation. Superheavy nuclei propagate further than lighter nuclei in certain energy ranges. The models developed are publicly available as open-source software.

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Lester, G. A. "A computing structure for data acquisition in high energy physics." Thesis, University of Salford, 1988. http://usir.salford.ac.uk/2168/.

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A review of the development of parallel computing is presented, followed by a summary of currently recognised types of parallel computer and a brief summary of some applications of parallel computing in the field of high energy physics. The computing requirement at the data acquisition stage of a particular set of high energy physics experiments is detailed, with reference to the computing system currently in use. The requirement for a parallel processor to process the data from these experiments is established and a possible computing structure put forward. The topology proposed consists of a set of rings of processors stacked to give a cylindrical arrangement, an analytical approach is used to verify the suitability and extensibility of the suggested scheme. Using simulation results the behaviour of rings and cylinders of processors using different algorithms for the movement of data within the system and different patterns of data input is presented and discussed. Practical hardware and software details for processing equipment capable of supporting such a structure as presented here is given, various algorithms for use with this equipment, e. g. program distribution, are developed and the software for the implementation of the cylindrical structure is presented. Appendices of constructional information and all program listings are included.

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Alvarez, del Castillo Astiazarán Ricardo Ignacio. "The Kemmer equation for pion-nucleus scattering." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59958.

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A relativistic equation, known as the Kemmer-Duffin-Petiau (KDP) equation, for spin-0 particles is used to study low energy pion-nucleus scattering. This equation is linear and the optical potential is completely local in contrast to the quadratic Klein-Gordon equation which contains gradient terms in the p-wave part of the potential when applied to pion-nucleus scattering. Specifically, if we use an almost minimal coupling scheme (scalar and vector potentials), then this equation is equivalent to the Klein-Gordon equation with a Kisslinger potential and an effective Ericson-Ericson-Lorentz-Lorenz parameter $ lambda$ = 3. Experimentally, the $ lambda$ parameter is subject to uncertainty and no agreement has been reached about its value, though it must be greater than 1.6. The full KDP optical potential is obtained by taking the impulse terms from $ pi$-N scattering data and folding this with the nuclear density and then adding a true absorption contribution which is quadratic in the densities. It is shown that good agreement can be obtained for elastic scattering on light nuclei at low energies.

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Sirois, Yves. "Probes of quark matter formation in high energy 16O-nucleus collisions." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75666.

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I present the measurements, analysis and results obtained with the NA34 experiment at the CERN European laboratory, on the global characteristics of particle production in ultra-relativistic oxygen-nucleus collisions, at incident energies of 60 and 200 GeV/nucleon. The observed properties of the particle flow are analysed in the framework of phenomenological models inspired by quantum chromodynamics. From this analysis, novel information emerges concerning the mechanisms and space-time evolution of the soft-hadronic processes in short-lived extended volumes of matter at extreme densities and temperature. We consequently study the parameters and critical conditions under which nuclear collisions could allow the observation of a phase transition from hadronic matter towards a new state of deconfined quark-gluon plasma matter.

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Oliveira, Renato Aparecido Negrão de. "Estudo da energia transversal em colisões Au+Au para energias entre 7.7 e 200 GeV." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-20012015-112105/.

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O objetivo de investigar colisões de íons pesados no regime relativístico é de estudar os quarks e glúons em condições extremas de pressão, densidade e temperatura, reproduzindo as condições da matéria nos instantes iniciais da formação do universo. Nesse trabalho, a energia transversal ET foi investigada para colisões Au+Au no experimento STAR no RHIC a energias de feixe no intervalo de 7.7 à 200 GeV. A dependência do ET normalizado pelo número de participantes em função da centralidade e energia de colisão foi medida, bem como a dependência do ET dividido pela densidade de partículas carregadas em função da energia de colisão para colisões centrais. Os resultados desse estudo indicam que para energias menores do que 7.7 GeV, a energia transversal média por unidade de carga produzida varia significativamente com o aumento da energia de colisão, atingindo o limite de saturação para o intervalo de energias maiores do que 7.7 GeV, onde essa razão passa a ser praticamente constante em função da energia de colisão. Por fim, a componente eletromagnética da energia transversal também foi medida, e os resultados indicam que para as energias mais baixas o estado final é dominado por bárions, ao passo que para altas energias o mesmo é dominado por mésons.
The goal of relativistic heavy-ion collisions is to study the behavior of quarks and gluons under extreme conditions of pressure, density and temperature, such as those expected to have existed in the the beginning of the universe. In this work, the transverse energy ET was investigated for Au+Au collisions measured with the STAR experiment at RHIC with beam energies from 7.7 to 200 GeV. The centrality and collision energy dependence of ET per number of participants was measured, as well as the energy dependence for the ET per charged particles in central collisions. The results indicate that for collision energies less than 7.7 GeV the average transverse energy per unit charge varies significantly with increasing collision energy, reaching the saturation limit for energies higher than 7.7 GeV, where this ratio becomes almost constant. The electromagnetic fraction of the total ET was estimated, and the results are in agreement with a final state dominated by baryons, for lower energies, and a meson dominated state for higher energies.

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Williams, Megan L. (Megan Louise). "An investigation of GaAs as a particle detector material for high energy physics applications." Thesis, The University of Sydney, 1997. https://hdl.handle.net/2123/27617.

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This thesis describes the examination of some of the properties of Gallium Arsenide (GaAs), primarily semi-insulating (SI) GaAs, in an effort to assess their impact on the performance of high energy physics (HEP) detectors fabricated from this material. Of particular interest was the shape of the electric field across such devices and its progression with increasing reverse bias, and the impurities and defect levels in the material. These combine to dictate the charge transport properties of the material which in turn determine the quality of the signal from SI GaAs devices. Chapter 1 discusses the relevance of SI GaAs devices to the Large Hadron Collider and ATLAS, and introduces the primary concerns regarding the properties of the material including the growth methods. The fabrication of the devices investigated here is described in Chapter 2 as are routine measurements such as current-density vs voltage, capacitance—voltage (CV) and (x—spectroscopy measurements. Chapter 3 details the use of the transient current technique to study the current pulses which result due to the motion of charge carriers in the material. These current pulses are directly related to the shape and strength of the electric field across the devices, and an investigation into whether Ramo’s Theory correctly predicts the current pulses in SI GaAs was undertaken. The investigation included the effects of circuit parameters and the electron lifetime, resulting in a better understanding of the field shape as well as the sensitivity of the current pulses to these effects. Chapter 4 describes the application of charge transient spectroscopy (QTS) and optical QTS to SI GaAs. It is demonstrated that these techniques are ideal for investigating the majority and minority carrier traps in both conducting and high resistivity GaAs. Chapter 5 details the low—frequency CV measurements for SI GaAs devices, and shows that it is a promising way of obtaining information about the electron lifetime in the material and the concentration of deep level donors. Chapter 6 summarises the main findings of the thesis and describes further experiments for and improvements to the techniques presented here.

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Cox, David Christopher. "A measurement of the neutral current neutrino-nucleon elastic cross section at MiniBooNE." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3297941.

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Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008.
Title from dissertation home page (viewed Sept. 30, 2008). Source: Dissertation Abstracts International, Volume: 69-03, Section: B, page: 1710. Adviser: Rex Tayloe.

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26

Tabti, Rahma. "Soft dilepton production in ultrarelativistic heavy-ion collisions." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23428.

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We investigate and compare two field theoretical formalisms, namely, the former state-of-the-art but noncovariant Ruckl formula-based formalism developed by K. Haglin and C. Gale, and a more recent covariant formalism developed by P. Lichard, for lepton pair production via soft virtual bremsstrahlung in hadronic reactions. A quantitative study of the discrepancy between both formalisms with regard to rates and total yields of $e sp{+}e sp{-}$ and $ mu sp{+} mu sp{-}$ pair production from radiative pion and quark (antiquark) scattering in ultrarelativistic heavy-ion collisions is made. Dilepton production rates are calculated using the independent particle approximation from kinetic theory, and total dilepton yields are obtained by integrating these rates over the space-time evolution of the heavy-ion collision as dictated by Bjorken's longitudinal hydrodynamic model. All rates and total yields of $e sp{+}e sp{-}$ and $ mu sp{+} mu sp{-}$ pair production with invariant masses less than 300 MeV turn out to be overestimated in the Ruckl formula-based formalism.

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Teodorescu, Octavian. "Hadron properties and meson mixing effects in hot and dense strongly interacting matter." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38423.

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In the present thesis, the properties of hadrons in a dense medium are studied. The collective excitations related to the propagation of scalar and vector mesons in dense nuclear matter are discussed in a relativistic mean field model. Finite temperature effects on the meson properties in nuclear matter are also considered. One of the main concerns of the present thesis is the evaluation of symmetry-breaking effects induced by the dense matter. Special emphasis is put on the study of scalar-vector meson mixing effect, a pure density-dependent effect forbidden in vacuum on account of the Lorentz symmetry. In this direction, a new symmetry-breaking effect---the rho-a 0 meson mixing---is revealed and studied in detail along with a similar effect induced by the o-sigma mixing. The possibility of a new dilepton channel, arising from pi-eta collisions and mediated by rho-a 0 mixing, is further discussed in a relativistic kinetic model. The effects of o-sigma mixing on the amplitude of the dilepton production process from pion annihilation is also evaluated in a similar manner. The possibility of observing such symmetry-breaking effects in nucleus-nucleus collision experiments is investigated. For the space-time evolution of the matter formed during the collision, a thermal model is employed and the equation of state is determined from the interacting nuclear matter within the scope of a mean field model. We argue that such processes can be observed in the dilepton spectra at GSI/SIS energies, while they are not so evident at higher energy experiments performed at CERN/SPS.

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Wang, Gang 1958 Nov 28. "Transverse energy and charged particle multiplicity in 14.6 GeVc proton-nucleus collisions." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28956.

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Transverse energy and charged particle multiplicity produced in 14.6 GeV/c p + Al and p + Pb collisions have been studied using the E814 set-up at the BNL-AGS. Measurements of d$ sigma$/d$E sb{T}$, d$E sb{T}$/d$ eta$,d$ sigma$/d$N sb{c}$, and d$N sb{c}$/d$ eta$ are presented. From the present data the mean transverse energy per particle is obtained and it is compared to values observed in Si induced collisions at the same energy. In contrast to what is observed in nucleus-nucleus collisions, a very weak correlation is found between the transverse energy and the charged particle multiplicity. These results are compared to the predictions of various theoretical models used to describe heavy-ion collisions. The event generators RQMD and HIJET reproduce well the pseudorapidity distribution of both the transverse energy and charged particle multiplicity, whereas FRITIOF fails to reproduce the measured distributions. Contrary to what had been suggested previously in a Si + A study, the present study shows that the pseudorapidity dependence of charged particle multiplicity distributions do not follow KNO scaling.

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29

He, Weihong. "Double spin asymmetry in inclusive neutral pion production for longitudinally polarized proton proton collisions at center of mass energy = 200GeV at the Endcap Electromagnetic Calorimeter at STAR." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3331320.

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Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008.
Title from PDF t.p. (viewed on Jul 27, 2009). Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6881. Adviser: Scott W. Wissink.

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Katori, Teppei. "A measurement of the muon neutrino charged current quasielastic interaction and a test of Lorentz violation with the MiniBooNE experiment." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3344580.

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Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008.
Title from PDF t.p. (viewed on Oct. 7, 2009). Source: Dissertation Abstracts International, Volume: 70-02, Section: B, page: 1094. Adviser: Rex Tayloe.

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31

Torrieri, Giorgio. "Statistical hadronization phenomenology in heavy ion collisions at SPS and RHIC energies." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280537.

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This dissertation examines the phenomenology of statistical hadronization at ultrarelativistic energies. We start with an overview of current experimental and theoretical issues in Relativistic heavy ion physics. We then introduce statistical hadronization, and show how it gives a description of particle abundances and spectra through relativistic covariance and entropy maximization. We argue that several statistical hadronization models are possible; In particular, a distinction can be made between equilibrated staged freeze-out in which post-formation hadron interactions play an important role in determining final-state observables, and non-equilibrium sudden freeze-out where spectra and abundances get determined at the same time and further interactions are negligible. We attempt to falsify sudden freeze-out by examining whether particle abundances and spectra can be described using the same formation temperature. This is done both in the chemical equilibrium framework, and using a chemical non-equilibrium ansatz. Our fits to experimental data suggest that the sudden freeze-out model explains both the particle abundances and spectra. We then try to extract the particle formation temperature, and quantify post-freeze-out hadronic interactions using experimentally observable resonances. We discuss observed resonances and suggest further measurements that have the potential to distinguish between the possible freeze-out scenarios experimentally. Finally, we infer from experimental data how particle formation proceeds in spacetime, in particular whether freeze-out dynamics agrees with the sudden freeze-out expectation. We examine particle spectra, and show that they are not sensitive enough to pick the right freeze-out dynamics. We suggest resonances and azimuthal anisotropy as experimental probes for this task.

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Babukhadia, Levan. "Rapidity dependence of the single inclusive jet cross section in proton-antiproton collisions at the center-of-mass energy of 1.8 TeV with the Dzero detector." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/284340.

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We have made a precise measurement of the rapidity dependence of inclusive single jet production cross section d²s/dE(T)dη in pp̄ collisions at √s=1.8 TeV. The measurement is based on integrated luminosity of 92 pb⁻¹ data collected by the D⊘ detector at the Tevatron Collider, Fermi National Accelerator Laboratory. The cross sections are reported as a function of jet transverse energy in five pseudorapidity (η) intervals up to η = 3.0. The experimental results are in good agreement with the theoretical predictions from next-to-leading order perturbative quantum chromodynamics.

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Valerio, Peter Michael 1968. "Heavy quark production in heavy-ion collisions." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/288922.

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The results of the full next-to-leading-order calculation of open charm production cross section, via hard parton scattering, for both hadronic and heavy-ion collisions at RHIC and LHC energies are presented. In addition to the total cross section, the transverse momentum and rapidity distributions are included. An effective K-factor which encapsulates the next-to-leading-order corrections and the nuclear effects is presented. The open charm yield will be measured through the correlated dileptons produced when the charm decays. An important background comes from the decay of bottom quarks. Therefore, the open bottom yield from hard parton scatterings is presented. The first next-to-leading-order calculation of the thermal heavy quark production is presented, as well as the dimuon spectrum from both the thermal and the initial fusion charm and bottom production at RHIC energies.

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Lima, Caio Eduardo Ferreira. "Estudo da energia transversal eletromagnética em colisões Pb-Pb a √SNN = 2.76 TeV com o experimento ALICE." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-04072017-154951/.

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A física de altas energias, mais especificamente o estudo de colisões entre de íons pesados relativísticos tem como objetivo o estudo do comportamento de quarks e glúons em condições extremas de temperatura, pressão e densidade. Tais condições levam à formação de um novo estado da matéria chamado Plasma de Quarks e Glúons (QGP, do inglês Quark-Gluon Plasma). Medidas de observáveis globais tem sido usadas como uma importante ferramenta para a caracterização desse novo estado. Entre esses observáveis, a energia transversal por unidade de rapidez (dET/dy) das partículas emitidas em uma colisão entre íons pesados pode ser usada como evidência da formação do QGP. Este trabalho propõe um procedimento para obtenção da energia transversal eletromagnética, que é um importante componente da energia transversal total, em colisões Pb-Pb no experimento ALICE no LHC. O estudo foi feito através de simulações de Monte Carlo e validou o procedimento proposto com uma diferença sistemática em função da centralidade em torno de 2%.
High energy physics with heavy ion collisions studies quarks and gluons under extreme conditions of temperature, pressure and density. Such conditions lead to the formation of a new state of matter called the Quark-Gluon Plasma (QGP). The measurement of global observables have been used as an important tool for the characterization of this new state. Among these observables, the transverse energy per unit of rapidity (dET/dy) from particles emitted in a heavy ion collision can be used as evidence of QGP formation. The work proposes a procedure to obtain the transverse electromagnetic energy, an important component of total transverse energy, in Pb-Pb collisions measured by the LHC-ALICE experiment. The study was done using Monte Carlo simulations, and validated the proposed procedure with a systematic difference as function of the centrality around 2%.

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Woods, P. J. "Mass measurements of light neutron rich nuclei." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374579.

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36

Morejon, Leonel [Verfasser]. "New Interaction Models of Ultra-high-energy Cosmic Rays from a Nuclear Physics Approach / Leonel Morejon." Berlin : Humboldt-Universität zu Berlin, 2021. http://d-nb.info/1230406751/34.

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37

Guez, David. "Modélisation et simulation de paramètres critiques de la première station du spectromètre dimuons d'ALICE." Phd thesis, Université Paris Sud - Paris XI, 2003. http://tel.archives-ouvertes.fr/tel-00006047.

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38

Rapp, Benjamin. "Production de dimuons en reactions p-p et Pb-Pb avec ALICE: le détecteur V0 et les résonances de basse masse." Phd thesis, Université Claude Bernard - Lyon I, 2004. http://tel.archives-ouvertes.fr/tel-00007147.

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Les collisions d'ions lourds ultra relativistes permettent, grâce à la haute densité d'énergie atteinte, de produire un nouvel état de la matière où les quarks ne sont plus confinés à l'intérieur des nucléons. Cet état, appelé Plasma de Quarks et de Gluons sera étudié par l'expérience ALICE située auprès du collisionneur LHC du CERN. Dans cette thèse est décrit le détecteur V0, hodoscopes de scintillateurs situés de part et d'autre du point de collision des faisceaux au centre de l'expérience ALICE. Il joue un rôle essentiel dans ALICE. Il fournit le déclenchement de niveau 0 de l'expérience, filtre une grande partie du bruit de fond instrumental et permet de mesurer la luminosité en collisions proton-proton. Le développement de ce détecteur ainsi que ses performances sont détaillés. La physique des dimuons est aussi abordée dans le cas plus particulier de l'étude des résonances de basse masse. La région de masse invariante inférieure à 3 GeV/c$^2$ contient une importante information sur le milieu chaud et/ou dense créé lors des collisions d'ions lourds. La modification des propriétés des résonances $\rho^0$, $\omega$ et $\phi^0$ est un signal potentiel de la restauration de la symétrie chirale. La possibilité d'observer ces résonances dans leur voie de désintégration en paires de muons est évaluée en collisions p-p et Pb-Pb avec le spectromètre dimuon d'ALICE.

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39

Turbide, Simon. "Electromagnetic radiation from matter under extreme conditions." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102221.

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The subject of this thesis is the production of electromagnetic radiations during relativistic heavy ions collisions. Since they constitute one of the major ways to probe the presence of a quark-gluon plasma (QGP), their evaluation through theoretical models is very important. The photon production at low-to intermediate transverse momentum (pT) is first studied. The photon production rate in a mesonic gas is evaluated within a massive Yang-Mills (MYM) approach. Earlier calculations are reexamined with additional constraints, including new production channels and with the inclusion of form-factors. Adding primordial N-N contribution and existing baryonic and QGP production rates, we can reproduce the photon spectra observed at the Super Proton Synchrotron (SPS). The intermediate to high-p T region is dominated by the physics of jets. A treatment, complete to leading-order in the strong coupling, is used to calculate energy loss in the strongly interacting medium. This approach is convolved with a physical description of the initial spatial distribution of jets and with an expansion of the emission zone. The role played by jet-plasma interactions is highlighted, showing that they dominate in the range 2 < p T < 4 GeV, at the Relativistic Heavy Ion Collider (RHIC). This mechanism has an important impact on both the total photon yield and the photon azimuthal asymmetry, turning the coefficient v 2 negative. Finally, the dilepton production at high p T is calculated with hard-thermal loops (HTL) effects, showing, that in perfect analogy with real photons, jet-plasma interactions also dominate the dilepton yield around pT = 4 GeV.

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40

Marsh, James W. "High resolution measurements of neutron energy spectra from Am-Be and Am-B neutron sources." Thesis, Kingston University, 1990. http://eprints.kingston.ac.uk/20540/.

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A modelling methodology, consisting of tools and techniques, has been developed to achieve quality improvement in any area of a manufacturing organisation. A 3 step approach was piloted within the Test Department at ICL Kidsgrove which tests printed circuit boards manufactured at the factory. The first step was to produce a full process model and to use this to highlight non-conformances. The next step was to develop a cost of quality model. The information from this model is used to take cost prioritised and cost justified corrective actions. The final step is to prepare a procedure which defines to the customers how to use the cost of quality information effectively. This 3 step pilot methodology was then applied to indirect functions such as Finance and Maintenance through an implementation team. The process modelling step was also developed in other quality applications such as auditing and procedure preparation. The final methodology is currently being considered for adoption as a problem solving approach throughout ICL. The process modelling step is being incorporated into auditor training. The modelling methodology, developed through this research, provides a structured, disciplined approach to quality improvement.

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Damrongkijudom, Nyanpen. "Analysis of lepton contamination in high energy x-ray beams." Access electronically, 2007. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20080121.120415/index.html.

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42

Everett, Derek S. "Quantifying the Quark Gluon Plasma." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619097453787371.

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43

Bock, Nicolas. "Femtoscopy of proton-proton collisions in the ALICE experiment." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316184643.

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44

Quinn, Bruce David 1955. "Dose rate measurements in the cobalt-60 gamma irradiation facility using thermoluminescent dosimeters." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277923.

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A dose rate measurement survey was performed at various locations inside the radiation chamber of the Cobalt-60 gamma irradiation facility located in Room 130, Building 20 at the University of Arizona. TLDs were used for the dose rate measurements. It was observed that the dose rates decrease rapidly with increasing distance from the source. Also, dose rates decreased with increased distance away from the centerline of the radiation chamber which is indicative of the position of the effective center of the source. Percent dose rates with respect to the dose rate of the calibration position were tabulated.

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45

Penn, Gregory Evan 1969. "Evolution of the distribution of high energy nuclei and induced collective modes in plasmas." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/46596.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1998.
Includes bibliographical references (p. 177-181).
Recent experiments in plasmas undergoing fusion have shown evidence of novel processes which are correlated with the onset of fusion reactions. In view of such evidence and observed effects of the injection of high energy neutral beams in laboratory plasmas, as well as the existence of subpopulations of high energy particles in astrophysical plasmas, there is a rich variety in the possible interactions of energetic nuclei within a plasma. This thesis examines the effects of the He nuclei produced by fusion in a magnetically confined plasma. Both single-particle effects and interactions with collective modes in the plasma will be considered. Part of this research will focus on the distribution of high energy nuclei undergoing motion in unperturbed orbits. This work utilizes appropriate symmetry properties and conservation laws, including the conservation of angular momentum in a toroidally symmetric configuration. Considering the various time scales involved in the evolution of the distribution function, a reasonable form for the distribution function of fusion products is derived. With this distribution function, basic properties such as the first-orbit losses out of the plasma chamber and geometric effects on the distribution function can be deduced. A major role is played by magnetically trapped particles, which can undergo wide excursions away from magnetic field surfaces due to their high energy. The resulting distribution function displays a strong contrast between the central region of the plasma, where the fusion reaction rate for the production of a-particles is greatest, and the outermost regions of the plasma. In particular, at the outer edge particles are concentrated furthest away from the symmetry axis of the toroidal configuration, where the magnetic field is at its lowest. The velocity-space distribution function is dominated by trapped particles which undergo large radial excursions; these particles are not deeply trapped and have pitch angles close to those of passing particles. Another topic examined is the resonant interactions of fusion products with an internal mode of the plasma referred to as the "contained mode", whose local properties are analogous to those of a magnetosonic-whistler wave. The resonance occurs for modes whose frequency lies at multiples of the cyclotron frequency of the energetic particles. The contained mode has been shown to be localized in a thin radial shell towards the edge of the plasma column. Key features examined are the mode frequency, localization and radial extent of the mode, and how these properties are affected by the direction of mode propagation. As these modes can have frequencies larger than the fusion product cyclotron frequency, they can undergo resonant interactions with the small population of particles formed by fusion processes. Such interactions can lead to an instability of the collective mode which draws energy from the fusion products. The induced growth rates are calculated for parameters typical of recent experiments in burning plasmas resulting in the formation of a-particles. These experiments have observed enhanced radiation emission at harmonics of the fusion product cyclotron frequencies and it is argued that this anomalous ion cyclotron emission (ICE) is associated with the excitation of the contained modes by a-particles. According to this model, this emission can yield information about the a-particle distribution. In addition, these modes will modify the distribution of a-particles, offering an alternative to collisional processes for the exchange of energy with the background plasma of which slowing down of a-particles on electrons predominates. Such a mechanism would impart energy from fusion to the plasma ions without having to first heat the electron population. The effects of the eventual loss of energy of a-particles to this collective mode are illustrated and compared to collisions.
by Gregory Evan Penn.
Ph.D.

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46

Burgugi, Rogerio Gregorio. "Fragmentação nuclear em colisões de íons pesados a energias relativísticas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-23102009-093957/.

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Foi investigada a correlação entre a energia transversa (ET) produzida e a energia de partículas neutras (En) emitidas em colisões de íons de 28Si (plab=14.6 GeV/c por nucleon) com alvos de Al, Cu e Pb, estudadas pelo Experimento 814 no acelerador AGS do Laboratório Nacional de Brookhaven. A correlação entre a energia transversa e a energia dianteira produzida em colisões com emissão dos fragmentos 2H, 3H, 3He, 4He, 6He, 5Li e 6Li também foi investigada. Foi observado que a energia En dianteira produzida pelas partículas neutras tem uma forte dependência com a energia transversa ET produzida na colisão. Uma parametrização eficiente dos dados é obtida utilizando um modelo estatístico que relaciona o numero de espectadores da colisão com o numero de nêutrons detectados na região dianteira. As distribuições de momento desses fragmentos foram investigadas através do modelo de Goldhaber e os seus respectivos parâmetros 0 foram calculados para os eventos referentes as colisões de 28Si com alvos de Al, Cu e Pb.
We carried out a study of the forward neutral energy (En) and its correlation with the produced transverse energy (ET ) in collisions of 28Si ions (plab=14.6 GeV/c per nucleon) with Al, Cu, and Pb targets, investigated by Experiment 814 at the Brookhaven AGS. The correlation of the produced transverse energy with forward neutral energy from fragments 2H, 3H, 3He, 4He, 6He, 5Li and 6Li was also investigated. We find that the forward neutral energy En has a strong dependence on transverse energy ET produced in the collision. An efficient parametrization of this data set is accomplished through the use of a statistical model which relates the number of spectators in the collision to the number of neutrons detected in the forward direction. Momentum distributions of the fragments were investigated through the use of the Goldhaber model and the 0 parameter was calculated to each of the fragments in reactions of 28Si with Al, Cu and Pb targets.

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Wilson, Anna Naomi. "Dipole transitions in superdeformed nuclei in the A=190 region." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307632.

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Arms, Kregg E. "Study of tau lepton decays to three charged hadrons and one neutral pion." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1112803154.

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Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xv, 81 p.; also includes graphics (some col.) Includes bibliographical references (p. 79-81). Available online via OhioLINK's ETD Center

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Padro, Daniel. "Solid state NMR study of quadrupolar nuclei at high magnetic fields." Thesis, University of Warwick, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248866.

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Matthews, M. T. "A study of nucleon spin structure through polarised muon polarised proton deep inelastic scattering." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233868.

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Dissertations / Theses on the topic 'High-energy nuclear physic'

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