Journal articles: 'Hadronic decay study'

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Sadhu, Samrangy. "Study of in-Medium Energy Loss with Heavy-Flavour Correlations in pp and Pb-Pb Collisions with ALICE at the LHC." Proceedings 10, no. 1 (April 29, 2019): 43. http://dx.doi.org/10.3390/proceedings2019010043.

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The azimuthal correlations between heavy-flavour hadrons or heavy-flavour decay electrons with charged particles in Pb-Pb collisions give insight on the modification of charm-jet properties in nucleus-nucleus collisions and the mechanisms through which heavy quarks in-medium energy-loss takes place. Studies in pp collisions, besides constituting the necessary baseline for nucleus-nucleus measurements, are important for testing expectations from pQCD-inspired Monte Carlo generators. In ALICE heavy-flavour hadrons are studied via their fully reconstructed hadronic decays (D mesons and Λ c baryon), via semileptonic decays of charmed baryons ( Λ c , Ξ c ) and via leptons coming from heavy-flavour hadron decays. In particular in the central barrel, η < | 0 . 8 | , the electrons from heavy-flavour hadron decays are investigated. This proceeding will include the study of azimuthal correlations of D mesons with charged particles in pp collisions and heavy-flavour decay electrons with charged particles in pp and Pb-Pb collisions at different energies available at the LHC. The Experimental results will also be compared with the expectations from POWHEG and PYTHIA event generators.

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DOCE, OTON VAZQUEZ. "KAONIC CLUSTERS AT DAFNE: THE AMADEUS EXPERIMENT." International Journal of Modern Physics A 24, no. 02n03 (January 30, 2009): 594–98. http://dx.doi.org/10.1142/s0217751x09044152.

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The AMADEUS experiment will perform the first complete experimental study of the case of the so-called Deeply Bound Kaonic Nuclear States or simply Kaonic Clusters. Such a study has deep consequences in a still open sector of the strangeness hadronic/nuclear physics: how the hadron masses and hadron interactions change in the nuclear medium with consequences on the structure of cold dense hadronic matter. AMADEUS will perform exclusive - full acceptance - measurements, all particles in the formation and decay processes will be detected.

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Aleshko, A., E. Boos, and V. Bunichev. "Study of the Drell-Yan process with the pair-production of polarized tau leptons in collisions of polarized proton beams." EPJ Web of Conferences 222 (2019): 03021. http://dx.doi.org/10.1051/epjconf/201922203021.

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The new method for studying polarized parton distribution functions via the Drell-Yan process with tau production is proposed. The hadronic decay of tau to single charged pi-meson and neutrino is utilised for determination of the polarization state of the tau-lepton. The key feature of our approach is that we do not sum over the polarizations states of tau, but preserve this information through energies ofpions produced in corresponding decays. The new method in addition to existing ones should improve the accuracy of measurements of polarized structure functions of hadrons. In the current work, the feasibility of such an approach is assessed through numerical simulations.

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Qin, Qin, Hsiang-Nan Li, Cai-Dian Lü, and Fu-Sheng Yu. "Study on branching ratios and direct CP asymmetries of D → PV decays." International Journal of Modern Physics: Conference Series 29 (January 2014): 1460209. http://dx.doi.org/10.1142/s2010194514602099.

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We study the non-leptonic two-body decays of D mesons decaying into one pseudoscalar meson (P) and one vector meson (V) in the factorization-asisted topological-amplitude approach. In this approach, the decay amplitudes are factorized into two parts, the short-distance contribution (Wilson coefficients) and the long-distance contribution (hadronic matrix elements). We predict the branching ratios of D → PV decays using a global fit with the non-perturbative parameters. Our results agree well with the experimental data. We also predict the direct CP asymmetries by combining short-distance dynamics associated with penguin operators and long-distance hadronic matrix elements determined by branching ratios. The large asymmetries in D+ → π+ρ0 and [Formula: see text] may be measurable in the LHCb and future Belle II experiments.

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DE ANGELIS, ALESSANDRO. "STUDY OF INTERMITTENCY IN HADRONIC Z0 DECAYS." Modern Physics Letters A 05, no. 29 (November 20, 1990): 2395–401. http://dx.doi.org/10.1142/s0217732390002754.

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The study of the factorial moments of the rapidity distribution and of the (y, ϕ) distribution for hadrons produced in the decay of the Z0, by means of the DELPHI detector at LEP, has shown no deviations from the predictions of Parton-Shower models. Intermittent behavior observed in the latter case has been found to be compatible with jet cascading mechanism.

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LÜ, CAI-DIAN. "CHARMLESS HADRONIC B AND Bs DECAYS IN PERTURBATIVE QCD APPROACH." International Journal of Modern Physics A 23, no. 21 (August 20, 2008): 3250–54. http://dx.doi.org/10.1142/s0217751x08041918.

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We review the perturbative QCD approach study of hadronic B decays. Utilizing the constrained parameters in these well measured decay channels, we study most of the possible charmless Bs → PP, PV and VV decay channels in the perturbative QCD approach. In addition to the branching ratios and CP asymmetries, we also give predictions to the polarization fractions of the vector meson final states. The size of SU (3) breaking effect is also discussed. These predictions can be tested by the future LHCb experiment.

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Golubev, Vladimir. "Study of the B → Xcℓν Decays and Determination of |Vcb|." International Journal of Modern Physics A 20, no. 16 (June 30, 2005): 3644–47. http://dx.doi.org/10.1142/s0217751x05027187.

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We report studies of semileptonic decays, B → Xcℓν, based on a sample of 88 million [Formula: see text] events recorded with the BABAR detector. We have measured four moments of the electron energy and hadronic mass distributions and determined the inclusive branching fraction, the CKM matrix element |Vcb|, and other heavy quark parameters, using Heavy Quark Expansions in the kinetic mass scheme. In addition, we have studied a large sample of B0 → D*-ℓ+ν decays and extracted the decay form factors and |Vcb|.

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MOHANTA, RUKMANI. "STUDY OF TWO-BODY HADRONIC DECAYS OF Λb BARYON IN THE HEAVY QUARK EFFECTIVE THEORY." International Journal of Modern Physics A 14, no. 30 (December 10, 1999): 4735–47. http://dx.doi.org/10.1142/s0217751x99002220.

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We investigate the two-body nonleptonic weak decays of Λb baryon into a Λc baryon and a pseudoscalar or vector meson in the framework of HQET. With the additional assumption of factorization the branching ratios and asymmetry parameters for various decay processes [Formula: see text] are obtained. Treating the s quark as heavy we have also applied HQET to study the decay process Λb→ΛJ/ψ and the estimated branching ratio for this process is lying within the present experimental limits.

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KUPSC, ANDRZEJ. "DECAYS OF η AND η' MESONS–AN INTRODUCTION." International Journal of Modern Physics E 18, no. 05n06 (June 2009): 1255–70. http://dx.doi.org/10.1142/s0218301309013488.

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Decays of η and η' mesons are a laboratory for low energy strong interactions. The rate of isospin breaking decays into three pions constrain ratios of the light quark masses. Particle distributions from hadronic decays allow to study the elementary processes of the low energy Quantum Chromodynamics: π - π and π - η interactions. Radiative and conversion decays of the η and η' mesons provide information about internal structure of the mesons and the decay mechanism is strongly influenced by vector meson resonances. The lecture gives an introduction to the common decays of η and η' mesons. The main theme of the lecture are three body decays: hadronic decays, radiative decays into π+π-γ, π0γγ and Dalitz decays into ℓ+ℓ-γ.

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ONYISI, PETER. "CHARM HADRONIC DECAY BRANCHING FRACTIONS FROM CLEO-C." International Journal of Modern Physics A 21, no. 27 (October 30, 2006): 5423–29. http://dx.doi.org/10.1142/s0217751x06034550.

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The CLEO-c experiment at the CESR e+e- storage ring has collected data with E cm = 3.77 GeV and E cm ~ 4.17 GeV to study the decays of charmed mesons. This paper discusses results on the hadronic branching fractions of the D0, D+, and [Formula: see text].

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Gupta, Pallavi, and A. Upadhyay. "Study of1DStrange Charmed Meson Family Using HQET." Advances in High Energy Physics 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/4957236.

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Recently LHCb predicted spin 1 and spin 3 statesDs1⁎(2860)andDs3⁎(2860)which are studied through their strong decays and are assigned to fit the13D1and13D3states in the charm spectroscopy. In this paper, using the heavy quark effective theory, we state that assigningDs1⁎(2860)as the mixing of13D1-23S1states is rather a better justification to its observed experimental values than a pure state. We study its decay modes variation with hadronic coupling constantgxhand the mixing angleθ. We appoint spin 3 stateDs3⁎(2860)as the missing1D 3-JPstate and also study its decay channel behavior with coupling constantgyh. To appreciate the above results, we check the variation of decay modes for their spin partners states, that is,1D2and1D2′, with their masses and strong coupling constant, that is,gxhandgyh. Our calculation using HQET approach gives mixing angle of the13D1-23S1state forDs1⁎(2860)to lie in the range (-1.6radians≤θ≤-1.2radians). Our calculation for coupling constant values givesgxhto lie within value range of0.17–0.20andgyhto be 0.40. We expect from experiments to observe this mixing angle to verify our results.

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LI, DE-MIN, HONG YU, and QI-XING SHEN. "STUDY ON HADRONIC DECAY OF THE LOWEST LYING GLUEBALLS WITH JPC=even++ TO TWO PSEUDOSCALAR MESONS." Modern Physics Letters A 15, no. 10 (March 28, 2000): 723–29. http://dx.doi.org/10.1142/s0217732300000700.

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Taking into account the possible glueball component in the final state mesons, we investigate the hadronic decay modes of the lowest lying glueballs (G) with J PC = even ++ to two pseudoscalar mesons (PP). The naive estimations of [Formula: see text] for scalar and tensor glueballs are given.

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Abreu, P., W. Adam, T. Adye, P. Adzic, G. D. Alekseev, R. Alemany, P. P. Allport, et al. "A study of the hadronic resonance structure in the decay τ→3πντ." Physics Letters B 426, no. 3-4 (May 1998): 411–27. http://dx.doi.org/10.1016/s0370-2693(98)00347-5.

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Bala, Renu. "Study of D-mesons using hadronic decay channels with the ALICE detector." Nuclear Physics B - Proceedings Supplements 210-211 (January 2011): 33–36. http://dx.doi.org/10.1016/j.nuclphysbps.2010.12.040.

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Singha, Subhash, Bedangadas Mohanty, and Zi-Wei Lin. "Studying re-scattering effect in heavy-ion collision through K* production." International Journal of Modern Physics E 24, no. 05 (May 2015): 1550041. http://dx.doi.org/10.1142/s021830131550041x.

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We have studied the K* production within a multi-phase transport model (AMPT) for Au + Au collisions at [Formula: see text] to understand the hadronic re-scattering effect on the measured yields of the resonance. The hadronic re-scattering of the K* decay daughter particles (π and K) will alter their momentum distribution thereby making it difficult to reconstruct the K* signal through the invariant mass method. An increased hadronic re-scattering effect thus leads to a decrease in the reconstructed yield of K* in the heavy-ion collisions. Through this simulation study, we argue that a decrease in K*/K ratio with the increase in collision centrality necessarily reflects the hadronic re-scattering effect. Since the re-scattering occurs in the hadronic phase and K* has a lifetime of 4 fm/c, we present a toy model-based discussion on using measured K*/K to put a lower limit on the hadronic phase lifetime in high energy nuclear collisions.

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SHEN, P. N., H. C. CHIANG, B. S. ZOU, W. H. LIANG, R. G. PING, F. Q. GUO, Z. Q. ZENG, Y. B. DING, and X. Q. LI. "SOME THEORETICAL ISSUES OF HADRON PRODUCTIONS AND PROPERTIES FROM J/ψ DECAYS." International Journal of Modern Physics A 20, no. 08n09 (April 10, 2005): 1712–19. http://dx.doi.org/10.1142/s0217751x05023220.

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J/ψ strong decay is one of the best places to study the hadronic structure and the strong interaction. In this talk, as the background contribution, the proton pole diagram contribution to the branching ratio and the angular distribution in [Formula: see text] decays is analyzed. The applicability of quark models is explored via [Formula: see text] process. The structures of N* s , especially Roper resonance, are discussed by studying J/ψ decays. The productions of possible multi-quark systems via charmonium and bottomonium strong/radiative decays are also investigated.

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FUJITA, Y., B. RUBIO, W. GELLETLY, B. BLANK, T. ADACHI, A. ALGORA, P. ASCHER, et al. "NUCLEAR WEAK RESPONSE FROM THE COMBINED STUDY OF β-DECAY AND CHARGE-EXCHANGE REACTION." International Journal of Modern Physics E 18, no. 10 (November 2009): 2134–39. http://dx.doi.org/10.1142/s0218301309014433.

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Studying the weak nuclear response, especially the Gamow-Teller (GT) transitions, of stable as well as unstable pf-shell nuclei, is one of the key issues in nuclear and astro-nuclear physics. We study the decay half-lives and the GT transitions starting from Tz = ±1 and ±2 mirror nuclei, respectively, by means of β decays and complementary hadronic (3 He , t) charge-exchange reactions. Under the assumption that isospin is a good quantum number, symmetry is expected for mirror nuclei and the GT transitions starting from the mirror nuclei. The half-lives and branching ratios and the measured strength distributions of GT transitions are compared and also combined for the understanding of the nuclear structure of pf-shell nuclei far-from-stability.

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on behalf of ALICE collaboration, Preeti Dhankher. "Multiplicity Dependence of Heavy-Flavour Hadron Decay Electron Production in Collisions at √sNN = 8.16 Measured with ALICE at the LHC." Proceedings 10, no. 1 (April 15, 2019): 28. http://dx.doi.org/10.3390/proceedings2019010028.

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A Large Ion Collider Experiment (ALICE) at the Large Hadron collider (LHC) is a heavy-ion dedicated experiment designed to study nuclear matter at extreme condition of high temperature and high density at which quarks are deconfined and give rise to a new state of matter known as Quark Gluon Plasma (QGP). Heavy flavours (charm and beauty), are produced in the initial stages of hadronic collisions in hard scattering processes and therefore are effective probes to study the QGP. In this contribution, recent measurements of the production of electrons from heavy-flavour hadron decays, their nuclear modification factor and the self-normalised yield measured up to 14 in collisions at √sNN = 8.16 TeV collected in LHC Run2 in 2016 are presented.

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Hesari, Hoda, Hamzeh Khanpour, Morteza Khatiri Yanehsari, and Mojtaba Mohammadi Najafabadi. "Probing the Top Quark Flavour-Changing Neutral Current at a Future Electron-Positron Collider." Advances in High Energy Physics 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/476490.

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We present a study to examine the sensitivity of a futuree-e+collider to the anomalous top flavour-changing neutral current (FCNC) to the gluon. To separate signal from background a multivariate analysis is performed on top quark pair and background events, where one top quark is considered to follow the dominant standard model (SM) decay,t→Wb, and the other top decays through FCNC,t→qg, whereqis au- or ac-quark. The analysis of fully hadronic FCNC decay of thett-pair is also presented. The 95% confidence level limits on the top quark anomalous couplings are obtained for different values of the center-of-mass energies and integrated luminosities.

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Cao, Jun, and Yao-Bei Liu. "Search for doubly-charged Higgs bosons through the diboson decay channel at the ILC." Modern Physics Letters A 31, no. 32 (October 5, 2016): 1650182. http://dx.doi.org/10.1142/s0217732316501820.

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The doubly-charged Higgs bosons [Formula: see text] are the typical particles predicted in the Georgi–Machacek (GM) model and their decay modes depend on the magnitude of the triplet vacuum expectation value (VEV) [Formula: see text]. In this paper, we focus on the study of their pair production process at the International Linear Collider (ILC): [Formula: see text], with the subsequent decay of two like-sign [Formula: see text] bosons through a pair of like-sign dileptons and the remaining two in their hadronic decays. The 5[Formula: see text] confidence level discovery reach at the ILC is also studied with two collision energies of 1.0 TeV and 1.5 TeV.

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Dhir, Rohit, C. S. Kim, and Sechul Oh. "Model-independent analysis of CP violation in charmed meson decays." International Journal of Modern Physics A 30, no. 17 (June 20, 2015): 1550104. http://dx.doi.org/10.1142/s0217751x15501043.

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We present a model-independent analysis of CP violation, inspired by recent experimental observations, in charmed meson decays. The topological diagram approach is used to study direct CP asymmetries for singly Cabibbo-suppressed two-body hadronic decays of charmed mesons. We extract the magnitudes and relative phases of the corresponding topological amplitudes from available experimental information. In order to get more precise and reliable estimates of direct CP asymmetries, we take into account contributions from all possible strong penguin amplitudes, including the internal [Formula: see text]-quark penguin contributions. We also study flavor SU(3) symmetry breaking effects in these decay modes and consequently predict direct CP asymmetries of unmeasured modes.

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Soldin, Dennis. "Atmospheric Muons Measured with IceCube." EPJ Web of Conferences 208 (2019): 08007. http://dx.doi.org/10.1051/epjconf/201920808007.

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IceCube is a cubic-kilometer Cherenkov detector in the deep ice at the geographic South Pole. The dominant event yield is produced by penetrating atmospheric muons with energies above several 100 GeV. Due to its large detector volume, IceCube provides unique opportunities to study atmospheric muons with large statistics in detail. Measurements of the energy spectrum and the lateral separation distribution of muons offer insights into hadronic interactions during the air shower development and can be used to test hadronic models. We will present an overview of various measurements of atmospheric muons in IceCube, including the energy spectrum of muons between 10 TeV and 1 PeV. This is used to derive an estimate of the prompt contribution of muons, originating from the decay of heavy (mainly charmed) hadrons and unflavored mesons. We will also present measurements of the lateral separation distributions of TeV muons between 150m and 450m for several initial cosmic ray energies between 1 PeV and 16 PeV. Finally, the angular distribution of atmospheric muons in IceCube will be discussed.

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ZMESKAL, JOHANN. "SEARCH FOR KAONIC NUCLEI AT DAΦNE2: THE AMADEUS PROJECT." International Journal of Modern Physics A 22, no. 02n03 (January 30, 2007): 374–79. http://dx.doi.org/10.1142/s0217751x07035550.

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The planned upgrade of DAΦNE at LNF with a peak luminosity in the order of L = 1033 cm -2 s -1 will be the ideal machine to search for and prove the existence of antikaon-mediated deeply bound nuclear cluster. Antikaon-mediated deeply bound nuclear clusters will allow the study of most important problems in hadron physics today, namely, how the hadron masses and hadron interactions change in the nuclear medium and what is the structure of cold dense hadronic matter. AMADEUS will use the KLOE detector with an additional dedicated target and detector system around the interaction zone to perform exclusive measurements – all particles in the formation and decay processes of deeply bound nuclear clusters will be detected. These measurements will prove beyond doubt the anticipated formation production of antikaon-mediated deeply bound nuclear clusters.

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ADLARSON, PATRIK, and MARCIN ZIELIŃSKI. "MEASUREMENT OF THE η → π+π-π0 DECAY WITH WASA-at-COSY DETECTOR." International Journal of Modern Physics A 26, no. 03n04 (February 10, 2011): 622–24. http://dx.doi.org/10.1142/s0217751x11052232.

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One of the objectives of the physics programme of the WASA-at-COSY facility is to study the isospin violating η hadronic decays into π+π-π0 systems driven by the term of QCD Lagrangian which depends on the d and u quark mass difference. These studies can be made in terms of the Dalitz plot parameters describing the density population which is proportional to the square of the amplitude |A(x, y)|2. This contribution describes the current status of the analysis of the η → π+π-π0 decay in the pd →3 Heη and as well in the pp → ppη reaction with WASA-at-COSY.

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Köksal, M., A. A. Billur, A. Gutiérrez-Rodríguez, and M. A. Hernández-Ruíz. "Sensitivity measuring expected on the electromagnetic anomalous couplings in the tt̄γ vertex at the FCC-he." International Journal of Modern Physics A 35, no. 28 (October 9, 2020): 2050178. http://dx.doi.org/10.1142/s0217751x2050178x.

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Starting from an effective Lagrangian for the [Formula: see text] interaction of the top-quark, we consider the electroweak production cross-section via charged current and through the [Formula: see text] signal. Further, we derive the sensitivity expected for the magnetic dipole moment [Formula: see text] and the electric dipole moment [Formula: see text] of the top-quark at the Future Circular Collider-hadron electron (FCC-he). We present our study for [Formula: see text], 10 TeV, [Formula: see text], 100, 300, 500, 1000 fb[Formula: see text], [Formula: see text] and [Formula: see text], 80%, [Formula: see text], respectively. We find that the sensitivity estimated on dipole moments of the top-quark is of the order of magnitude [Formula: see text] for both hadronic and leptonic decay modes of [Formula: see text]: [Formula: see text] and [Formula: see text] at 95% C.L. in the hadronic channel with unpolarized electron beam [Formula: see text]. Our results regarding the polarized electron beam for [Formula: see text] and [Formula: see text] are [Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text] at 95% C.L. in the hadronic channel. The corresponding results for the leptonic channel with [Formula: see text], 80% [Formula: see text] are [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text], respectively. The results for [Formula: see text] and [Formula: see text] in the leptonic channel are weaker than those corresponding to the hadronic channel by a factor of 0.75. Given these prospective sensitivities, the FCC-he is an alternative to study the anomalous couplings of the quark-top that would complement the studies of the LHC with cleaner environments.

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PAVLUNIN, VICTOR, and IAN SHIPSEY. "From factor ratio measurement in the decay Λc→Λ e+ ν." International Journal of Modern Physics A 16, supp01b (September 2001): 511–13. http://dx.doi.org/10.1142/s0217751x01007352.

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The hadronic current of the matrix element for the transition Λc→Λ e+ ν within the framework of HQET is parameterized in terms of two form factors. By studying the decay rate distribution in the space of the decay kinematic variables one can extract the ratio [Formula: see text] of the form factors. The first measurement1 of R was made by the CLEO collaboration in 1995. In this note we describe the study of the statistical and systematic errors for a 4.5 times larger data sample. The central value for R will be presented shortly.

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Yang, Rui-zhi, Ervin Kafexhiu, and Felix Aharonian. "Exploring the shape of the γ-ray spectrum around the “π0-bump”." Astronomy & Astrophysics 615 (July 2018): A108. http://dx.doi.org/10.1051/0004-6361/201730908.

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The “pion-decay” bump is a distinct signature of the differential energy spectrum of γ-rays between 100 MeV and 1 GeV produced in hadronic interactions of accelerated particles (cosmic rays) with the ambient gas. We use recent parametrisations of relevant cross-sections to study the formation of the “pion-decay” bump. The γ-ray spectrum below the maximum of this spectral feature can be distorted because of contributions of additional radiation components, in particular, due to the bremsstrahlung of secondary electrons and positrons, the products of decays of π±-mesons, accompanying the π0-production. At energies below 100 MeV, a non-negligible fraction of γ-ray flux could originate from interactions of sub-relativistic heavy ions. We study the impact of these radiation channels on the formation of the overall γ-ray spectrum based on a time-dependent treatment of evolution of energy distributions of the primary and secondary particles in the γ-ray production region.

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Vanek, Jan. "Production of Open-Charm Hadrons in AuAu Collisions at sNN=200GeV Mesured by the STAR Experiment +†." Proceedings 10, no. 1 (April 10, 2019): 10. http://dx.doi.org/10.3390/proceedings2019010010.

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Charm quarks are primarily produced at the early stages of ultra-relativistic heavy-ion collisions and can therefore probe the quark-gluon plasma throughout its whole evolution. Final-state open-charm hadrons are commonly used to experimentally study the charm quark interaction with the medium. Thanks to the excellent secondary vertex resolution provided by the Heavy Flavor Tracker, STAR is able to directly reconstruct D ± , D 0 , D s , and Λ c ± via their hadronic decay channels. The topological cuts for signal extraction are optimized using supervised machine learning techniques. In these proceedings, we present an overview of recent open charm results from the STAR experiment. The nuclear modification factors of open-charm mesons and Λ c ± /D 0 ratio are shown as functions of transverse momentum and collision centrality.

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CAMPANELLI, MARIO. "PHYSICS OF W BOSONS AT LEP2." International Journal of Modern Physics A 14, no. 21 (August 20, 1999): 3277–312. http://dx.doi.org/10.1142/s0217751x99001548.

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After the first observations of W bosons in leptonic interactions, about 4000 WW candidate events per experiment have been collected at LEP2. This data allows the measurement of the WW production cross section at different center-of-mass energies, as well as W decay branching fractions. The W hadronic branching fraction can be converted into a test of the unitarity of the CKM matrix, or into an indirect determination of the matrix element |V cs |. A more direct measurement coming from charm tagging is also performed. The W mass has been measured via the cross section (in the threshold region) and the direct reconstruction of the W decay products, using different techniques to account for the distortions due to experimental effects. The main systematic error to the mass reconstruction in the fully hadronic channel comes from QCD effects like Color reconnections and Bose–Einstein correlations, extensively studied in WW events. In e+e- collisions W pairs can be produced in s-channel via a three-vector boson vertex, so a direct study of the trilinear gauge boson couplings is possible. Modification of WW cross section and distributions of W production and decay angles would be an indication of nonstandard couplings, thus a first hint for the presence of new physics.

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QUIROGA-ARIAS, PALOMA, and SEBASTIAN SAPETA. "A COMPARATIVE STUDY OF JET SUBSTRUCTURE TAGGERS." International Journal of Modern Physics A 28, no. 18 (July 20, 2013): 1350087. http://dx.doi.org/10.1142/s0217751x13500875.

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We explicitly study how jet substructure taggers act on a set of signal and background events. We focus on two-pronged hadronic decay of a boosted Z-boson. The background to this process comes from QCD jets with masses of the order of mZ. We find a way to compare various taggers within a single framework by applying them to the most relevant splitting in a jet. We develop a tool, TOY-TAG, which allows one to get insight into what happens when a particular tagger is applied to a set of signal or background events. It also provides estimates for significance and purity. We use our tool to analyze differences between various taggers and potential ways to improve the performance by combining several of them.

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Radhakrishnan, Sooraj. "Measurements of charm hadron production and anisotropic flow in Au+Au collisions at 200 GeV with the STAR experiment at RHIC." EPJ Web of Conferences 171 (2018): 18006. http://dx.doi.org/10.1051/epjconf/201817118006.

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Heavy flavor quarks, owing to their large masses, are predominantly produced through initial hard parton scatterings in heavy-ion collisions, and thus are excellent probes to study properties of the strongly coupled Quark Gluon Plasma (sQGP) medium produced in these collisions. Measurements of anisotropic flow harmonics of heavy flavor hadrons can provide information on the properties of the medium, including the heavy flavor transport coefficient. Charm quark hadronization mechanism in the sQGP medium can be studied through measurements of yields of different charm hadrons. In these proceedings we report on the measurements of elliptic and triangular flow harmonics of D0 mesons as well as the yield ratios of D±s/D0 and Λ±c/D0 in Au+Au collisions at [see formula in PDF] = 200 GeV at RHIC with the STAR detector. These measurements use the STAR Heavy Flavor Tracker (HFT) to reconstruct charm hadrons via their hadronic decay channels. Results are compared to model calculations and the implications on the understanding of charm quark dynamics in the medium are discussed.

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Korobov, A. A., R. R. Akhmetshin, A. N. Amirkhanov, A. V. Anisenkov, V. M. Aulchenko, V. Sh Banzarov, N. S. Bashtovoy, et al. "Study of π+π−π+π− production with CMD-3 detector at the VEPP-2000 collider." EPJ Web of Conferences 212 (2019): 04009. http://dx.doi.org/10.1051/epjconf/201921204009.

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The cross section of the process e+e−→ π+π−π+π− has been measured using an integrated luminosity of 17 pb−1 collected with the CMD-3 detector in the center-of-mass energy range 650-1000 MeV. High-precision measurements of various hadronic cross sections are of great interest in relation with the problem of the muon anomalous magnetic moment g-2. This measurement can be also used to test the relation between the cross section of e+e−→ π+ π−π+ π− and the spectral function for the τ−→ π−π0π0π0 decay predicted by the conservation of vector current (CVC).

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LIU, JIE, QIANG YUAN, XIAOJUN BI, HONG LI, and XINMIN ZHANG. "NEUTRINO EMISSION FROM DARK MATTER ANNIHILATION/DECAY IN LIGHT OF COSMIC e± AND $\bar{p}$ DATA." International Journal of Modern Physics A 27, no. 06 (March 10, 2012): 1250024. http://dx.doi.org/10.1142/s0217751x12500248.

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A self-consistent global fitting method based on the Markov Chain Monte Carlo technique to study the dark matter (DM) property associated with the cosmic ray electron/positron excesses was developed in our previous work. In this work we further improve the previous study to include the hadronic branching ratio of DM annihilation/decay. The PAMELA [Formula: see text] data are employed to constrain the hadronic branching ratio. We find that the 95% (2σ) upper limits of the quark branching ratio allowed by the PAMELA [Formula: see text] data is ~0.032 for DM annihilation and ~0.044 for DM decay, respectively. This result shows that the DM coupling to pure leptons is indeed favored by the current data. Based on the global fitting results, we further study the neutrino emission from DM in the galactic center. Our predicted neutrino flux is some smaller than previous works since the constraint from γ-rays is involved. However, it is still capable to be detected by the forthcoming neutrino detector such as IceCube. The improved points of the present study compared with previous works include: (1) the DM parameters, both the particle physical ones and astrophysical ones, are derived in a global fitting way, (2) constraints from various species of data sets, including γ-rays and antiprotons are included, and (3) the expectation of neutrino emission is fully self-consistent.

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Ikeda, Yoichi. "Tetraquark candidate Zc(3900) from coupled-channel scattering - how to extract hadronic interactions? -." EPJ Web of Conferences 175 (2018): 01023. http://dx.doi.org/10.1051/epjconf/201817501023.

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We present recent progress of lattice QCD studies on hadronic interactions which play a crucial role to understand the properties of atomic nuclei and hadron resonances. There are two methods, the plateau method (or the direct method) and the HAL QCD method, to study the hadronic interactions. In the plateau method, the determination of a ground state energy from the temporal correlation functions of multi-hadron systems is a key to reliably extract the physical observables. It turns out that, due to the contamination of excited elastic scattering states nearby, one can easily be misled by a fake plateau into extracting the ground state energy. We introduce a consistency check (sanity check) which can rule out obviously false results obtained from a fake plateau, and find that none of the results obtained at the moment for two-baryon systems in the plateau method pass the test. On the other hand, the HAL QCD method is free from the fake-plateau problem. We investigate the systematic uncertainties of the HAL QCD method, which are found to be well controlled. On the basis of the HAL QCD method, the structure of the tetraquark candidate Zc(3900), which was experimentally reported in e+e- collisions, is studied by the s-wave two-meson coupled-channel scattering. The results show that the Zc(3900) is not a conventional resonance but a threshold cusp. A semi-phenomenological analysis with the coupled-channel interaction to the experimentally observed decay mode is also presented to confirm the conclusion.

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Lee, Yen-Jie. "Production of D0 meson in pp and PbPb Collisions at √SNN = 5.02 TeV with CMS." EPJ Web of Conferences 171 (2018): 17003. http://dx.doi.org/10.1051/epjconf/201817117003.

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Heavy flavour mesons are used as powerful tools for the study of the strongly interacting medium in heavy ion collisions as heavy quarks are sensitive to the transport properties of the medium. In these proceedings, D0 nuclear modification factors, comparing the yields in PbPb and pp collisions, and azimuthal anisotropies in PbPb collisions are reported. Prompt D0 mesons and their antiparticles have been measured with the CMS detector via the hadronic decay channels D0 → K−π+ and D0 → K+π− in PbPb and pp collisions at a centre-of-mass energy of 5.02 TeV. Nonprompt D0 from b quark decays are subtracted. The D0 results are compared to inclusive charged particles, non-prompt J/ψ mesons from b decays and B+ mesons in order to reveal possible meson mass dependence of the observables.

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BADALÀ, A., R. BARBERA, F. BLANCO, A. PULVIRENTI, F. RIGGI, G. LO RE, and G. S. PAPPALARDO. "SHORT LIVED RESONANCES IN ALICE." International Journal of Modern Physics E 16, no. 07n08 (August 2007): 2463–69. http://dx.doi.org/10.1142/s0218301307008100.

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The ability of the ALICE detector to reconstruct the K*(892)0 resonance in p – p and Pb – Pb collisions at LHC energies has been investigated, by means of a detailed study of simulated events. PYTHIA events for p – p collisions and HIJING events for Pb – Pb collisions have been generated and fully reconstructed. The K*(892)0 was identified by its hadronic decay into Kπ through invariant mass analysis. The combinatorial background has been estimated using an event-mixing technique for p – p events and a like-sign technique for the Pb – Pb ones. The role of the particle identification of the decay product is also discussed.

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BOITO, DIOGO. "PERTURBATIVE EXPANSION OF τ HADRONIC SPECTRAL FUNCTION MOMENTS." International Journal of Modern Physics: Conference Series 35 (January 2014): 1460442. http://dx.doi.org/10.1142/s2010194514604426.

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In the extraction of αs from hadronic τ decay data several moments of the spectral functions have been employed. Furthermore, different renormalization group improvement (RGI) frameworks have been advocated, leading to conflicting values of αs. Recently, we performed a systematic study of the perturbative behavior of these moments in the context of the two main-stream RGI frameworks: Fixed Order Perturbation Theory (FOPT) and Contour Improved Perturbation Theory (CIPT). The yet unknown higher order coefficients of the perturbative series were modelled using the available knowledge of the renormalon singularities of the QCD Adler function. We were able to show that within these RGI frameworks some of the commonly employed moments should be avoided due to their poor perturbative behavior. Furthermore, under reasonable assumptions about the higher order behavior of the perturbative series FOPT provides the preferred RGI framework.

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Šefčík, Michal. "Strangeness production in Pb-Pb collisions at LHC energies with ALICE." EPJ Web of Conferences 171 (2018): 13007. http://dx.doi.org/10.1051/epjconf/201817113007.

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The results on the production of strange and multi-strange hadrons (K0S, Λ, Ξ and Ω) measured with ALICE in Pb-Pb collisions at the top LHC energy of [see formula in PDF] = 5.02 TeV are reported. Thanks to its excellent tracking and particle identification capabilities, ALICE is able to measure weakly decaying particles through the topological reconstruction of the identified hadronic decay products. Results are presented as a function of centrality and include transverse momentum spectra measured at central rapidity, pT-dependent Λ/K0S ratios and integrated yields. A systematic study of strangeness production is of fundamental importance for determining the thermal properties of the system created in ultrarelativistic heavy ion collisions. In order to study strangeness enhancement, the yields of studied particles are normalised to the corresponding measurement of pion production in the various centrality classes. The results are compared to measurements performed at lower energies, as well as to different systems and to predictions from statistical hadronization models.

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Bashir, Inam-ul, Rameez Ahmad Parra, Riyaz Ahmed Bhat, and Saeed Uddin. "Particle Transverse Momentum Distributions in p-p Collisions at √sNN=0.9 TeV." Advances in High Energy Physics 2019 (April 8, 2019): 1–7. http://dx.doi.org/10.1155/2019/8219567.

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The midrapidity transverse momentum spectra of hadrons (p, K+, Ks0, ϕ, Λ, and (Ξ-+Ξ--)) and the available rapidity distributions of the strange hadrons (Ks0, (Λ+Λ-), (Ξ-+Ξ--)) produced in p-p collisions at LHC energy √sNN = 0.9 TeV have been studied using a Unified Statistical Thermal Freeze-out Model (USTFM). The calculated results are found to be in good agreement with the experimental data. The theoretical fits of the transverse momentum spectra using the model calculations provide the thermal freeze-out conditions in terms of the temperature and collective flow parameters for different hadronic species. The study reveals the presence of a significant collective flow and a well-defined temperature in the system thus indicating the formation of a thermally equilibrated hydrodynamic system in p-p collisions at LHC. Moreover, the fits to the available experimental rapidity distributions data of strange hadrons show the effect of almost complete transparency in p-p collisions at LHC. The model incorporates longitudinal as well as a transverse hydrodynamic flow. The contributions from heavier decay resonances have also been taken into account. We have also imposed the criteria of exact strangeness conservation in the system.

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Kaloskamis, N. I., C. N. Papanicolas, and And the OOPS Collaboration. "Study of the proton deformation using the Out-Of-Plane Spectrometers." HNPS Proceedings 9 (February 11, 2020): 244. http://dx.doi.org/10.12681/hnps.2785.

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Nucleon deformation can be studied through electro-excitation to the first nucleon resonance, the Δ+(1232), and quantified through the quadrupole amplitudes in the γ*Ν --> Δ transition. A search for these small amplitudes has been the fo cus of a series of measurements undertaken at Bates-MIT. A first set of in-plane data show evidence for strong resonant and non-resonant ("background") ampli tudes in the longitudinal-transverse interference, which is sensitive to leading order to quadrupole contributions. Using beams of polarized electrons and the technique of out-of-plane detection, a second data set was collected on the two hadronic decay channels. It contains the first measurement of the fifth structure function on the nucléon, which provides an important theoretical constraint on the "background" amplitudes. Planned future measurements will focus on refining the resonance- background decomposition which is absolutely necessary before conclusions on the issue of nucléon deformation can be drawn.

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CHEN, CHUAN-REN, SOURAV K. MANDAL, and FUMINOBU TAKAHASHI. "GAMMA-RAY CONSTRAINTS ON DECAYING DARK MATTER." Modern Physics Letters A 25, no. 11n12 (April 20, 2010): 969–75. http://dx.doi.org/10.1142/s0217732310000125.

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The anomalies in positron fraction observed in PAMELA and total flux of electrons and positron reported by Fermi can be explained by a decaying dark matter. The agreement between astrophysical background and observed data in anti-proton indicates a lep-tophilic dark matter and constrains the hadronic decay branching ratios. In this work, we study the constrains on decaying rates of a dark matter to various 2-body final states using the Fermi and HESS gamma-ray data. We find that µ+µ- or τ+τ- final state is preferred to simultaneously explain the excesses and meet the gamma-ray constrains.

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Acciari, V. A., S. Ansoldi, L. A. Antonelli, A. Arbet Engels, K. Asano, D. Baack, A. Babić, et al. "Studying the nature of the unidentified gamma-ray source HESS J1841−055 with the MAGIC telescopes." Monthly Notices of the Royal Astronomical Society 497, no. 3 (July 24, 2020): 3734–45. http://dx.doi.org/10.1093/mnras/staa2135.

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ABSTRACT We investigate the physical nature and origin of the gamma-ray emission from the extended source HESS J1841−055 observed at TeV and GeV energies. We observed HESS J1841−055 at TeV energies for a total effective time of 43 h with the MAGIC telescopes, in 2012 and 2013. Additionally, we analysed the GeV counterpart making use of about 10 yr of Fermi-LAT data. Using both Fermi-LAT and MAGIC, we study both the spectral and energy-dependent morphology of the source for almost four decades of energy. The origin of the gamma-ray emission from this region is investigated using multiwaveband information on sources present in this region, suggested to be associated with this unidentified gamma-ray source. We find that the extended emission at GeV–TeV energies is best described by more than one source model. We also perform the first energy-dependent analysis of the HESS J1841−055 region at GeV–TeV. We find that the emission at lower energies comes from a diffuse or extended component, while the major contribution of gamma rays above 1 TeV arises from the southern part of the source. Moreover, we find that a significant curvature is present in the combined observed spectrum of MAGIC and Fermi-LAT. The first multiwavelength spectral energy distribution of this unidentified source shows that the emission at GeV–TeV energies can be well explained with both leptonic and hadronic models. For the leptonic scenario, bremsstrahlung is the dominant emission compared to inverse Compton. On the other hand, for the hadronic model, gamma-ray resulting from the decay of neutral pions (π0) can explain the observed spectrum. The presence of dense molecular clouds overlapping with HESS J1841−055 makes both bremsstrahlung and π0-decay processes the dominant emission mechanisms for the source.

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SANUKI, TOMOYUKI. "REVIEW OF BALLOONS MUON MEASUREMENT IN THE ATMOSPHERE." International Journal of Modern Physics A 17, no. 12n13 (May 20, 2002): 1635–44. http://dx.doi.org/10.1142/s0217751x02011138.

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In order to study neutrino oscillation phenomena using atmospheric neutrinos, it is crucially important to calculate their absolute fluxes and spectral shapes accurately. Since production and decay processes of muons are accompanied by neutrino production, observations of atmospheric muons give fundamental information about atmospheric neutrinos. Atmospheric muons have been measured at various sites; from a ground level to a balloon floating altitude. Very precise measurement has been carried out on the ground. Muon growth curves are measured during balloon ascending periods. These data can be used to investigate hadronic interaction models. Investigations of atmospheric muons will improve accuracy of the neutrino calculations. Statistics in the muon measurement during balloon experiments are still insufficient. In order to improve the statistics drastically, dedicated muon experiments are very important.

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GIACOSA, FRANCESCO, and THOMAS WOLKANOWSKI. "PROPAGATOR POLES AND AN EMERGENT STABLE STATE BELOW THRESHOLD: GENERAL DISCUSSION AND THE E(38) STATE." Modern Physics Letters A 27, no. 39 (December 13, 2012): 1250229. http://dx.doi.org/10.1142/s021773231250229x.

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In the framework of a simple quantum field theory describing the decay of a scalar state into two (pseudo)scalar ones we study the pole(s) motion(s) of its propagator: besides the expected pole on the second Riemann sheet, we find — for a large enough coupling constant — a second, additional pole on the first Riemann sheet below threshold, which corresponds to a stable state. We then perform a numerical study for a hadronic system in which a scalar particle couples to pions. We investigate under which conditions a stable state below the two-pion threshold can emerge. In particular, we study the case in which this stable state has a mass of 38 MeV, which corresponds to the recently claimed novel scalar state E(38). Moreover, we also show that the resonance f0(500) and the stable state E(38) could be two different manifestations of the same "object". Finally, we also estimate the order of magnitude of its coupling to photons.

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Ambrogi, L., R. Zanin, S. Casanova, E. De Oña Wilhelmi, G. Peron, and F. Aharonian. "Spectral and morphological study of the gamma radiation of the middle-aged supernova remnant HB 21." Astronomy & Astrophysics 623 (March 2019): A86. http://dx.doi.org/10.1051/0004-6361/201833985.

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Aims. We investigate the nature of the accelerated particles responsible for the production of the gamma-ray emission observed from the middle-aged supernova remnant (SNR) HB 21. Methods. We present the analysis of more than nine years of Fermi LAT data from the SNR HB 21. We performed morphological and spectral analysis of the SNR by means of a three-dimensional binned likelihood analysis. To assess the intrinsic properties of the parent particle models, we fit the obtained gamma-ray spectral energy distribution of the SNR by both hadronic- and leptonic-induced gamma-ray spectrum. Results. We observe an extended emission positionally in agreement with the SNR HB 21. The bulk of this gamma-ray emission is detected from the remnant; photons up to ~10 GeV show clear evidence of curvature at the lower energies. The remnant is characterized by an extension of 0°.83, that is, 30% smaller than claimed in previous studies. The increased statistics allowed us also to resolve a point-like source at the edge of the remnant, in proximity to a molecular cloud of the Cyg OB7 complex. In the southern part of the remnant, a hint of an additional gamma-ray excess in correspondence to shocked molecular clouds is observed. Conclusions. The spectral energy distribution of the SNR shows evidence of a break around 400 MeV, which can be properly fitted within both the hadronic and leptonic scenario. The pion-decay mechanism reproduces well the gamma rays, postulating a proton spectrum with a slope ~2.5 and with a steepening around tens of GeV, which could be explained by the energy-dependent escape of particles from the remnant. In the leptonic scenario the electron spectrum within the SNR matches closely the locally measured spectrum. This remarkable and novel result shows that SNR HB 21 could be a direct contributor to the population of Galactic electrons. In the leptonic scenario, we find that the local electron spectrum with a break around 2 GeV, closely evokes the best-fitting parental spectrum within this SNR. If such a scenario is confirmed, this would indicate that the SNR might be a source of Galactic background electrons.

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Sepehri, A., M. E. Zomorrodian, A. Moradi Marjaneh, P. Eslami, and S. Shoorvazi. "The effect of Higgs boson radiation from TeV black holes on the hadronic cross section at the LHC." Canadian Journal of Physics 90, no. 1 (January 2012): 25–37. http://dx.doi.org/10.1139/p11-134.

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In curved space–time near TeV black holes many gluons and quarks produced by the Unruh effect interact with each other and create Higgs bosons. We study the Unruh effect and show that, for gluons and quarks, the internal stationary state of a Schwarzschild black hole can be represented by a maximally entangled two-mode squeezed state of outgoing and infalling Hawking radiation. We consider different channels for Higgs boson production near event horizons of mini black holes at the Large Hadron Collider (LHC) and obtain the cross section in each channel. We observe that the cross section of a Higgs boson produced via gluon fusion near a single black hole is much larger for smaller black hole masses. This is because the temperature of the black hole becomes larger as the mass becomes smaller and the thermal radiation of the gluons is enhanced. At lower mass, MBH < 4 TeV, the black hole will not be able to emit Higgs, but will still be able to produce a quark; for MBH < 3 TeV the black hole can only emit massless gluons. We show that as the black hole mass at the LHC increases (4 TeV < MBH < 8 TeV) most of the Higgs boson production is due to the Unruh effect near the event horizon of the black hole. Comparing these Higgs boson cross sections with Higgs boson cross sections in perturbative quantum chromodynamics, we find that micro black holes can be a source of Higgs production at the LHC. Finally, we calculate the effects of Higgs boson radiation due to mini black holes on the hadronic cross section at the LHC. We observe that as the order of perturbation theory increases this effect becomes systematically more significant because at higher orders there exist more channels for Higgs production and, in our calculations, Higgs decay into massive quark–antiquark pairs. At smaller masses, MBH < 2 TeV, the hadronic cross section at leading order is large while the cross sections at next-to-leading order and at next-to-next-to-leading order are rising at MBH ∼ 2 and 3 TeV, respectively, and exhibit a turn-over at moderate values of black hole mass.

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Del Grande, R., M. Bazzi, G. Belloti, A. M. Bragadireanu, D. Bosnar, A. D. Butt, M. Cargnelli, et al. "Studies of low-energy K- nuclear interactions by AMADEUS." EPJ Web of Conferences 182 (2018): 02035. http://dx.doi.org/10.1051/epjconf/201818202035.

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The goal of the AMADEUS experiment is to shed light on unsolved fundamental issues in the non-perturbative strangeness QCD sector through the study of lowenergy K- hadronic interactions with light nuclear targets. The main open questions are the controversial nature of the Δ(1405) state, which is investigated in hyperon-pion correlation studies, and the possible existence of exotic antikaon multi-nucleon clusters, whose search in K- induced reactions is intimately related to the studies of the K- multi-nucleon absorption processes in hyperon-nucleon/nucleus channels. The DAΦNE collider at the INFN-LNF provides unique monochromatic low-momentum kaons from the φ meson decay almost at-rest, suitable for the AMADEUS studies. The KLOE detector is exploited as an active target, in order to obtain excellent acceptance and resolution data for K- nuclear capture on H, 4He, 9Be and 12C, both at-rest and in-flight.

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Singh, Soram Robertson, and Barilang MAWLONG. "331-Z′ mediated FCNC effects on b → dμ+μ− transitions." International Journal of Modern Physics A 33, no. 36 (December 30, 2018): 1850225. http://dx.doi.org/10.1142/s0217751x18502251.

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We study the rare semileptonic [Formula: see text] and [Formula: see text] decay modes mediated by the quark level [Formula: see text] transition in this paper. We analyze observables such as the differential branching ratio, lepton polarization asymmetry and forward–backward asymmetry within the standard model in the large hadronic recoil region. We then analyze these observables within the 331 or [Formula: see text] model in which a new heavy [Formula: see text] boson contributes. The effects of the [Formula: see text]-mediated flavor changing neutral current (FCNC) transitions on these modes are examined by varying the mass [Formula: see text] and the model parameter [Formula: see text]. The new [Formula: see text] couplings are constrained by flavor observables of [Formula: see text] mixing. For the obtained parameter space, we observe [Formula: see text] sensitivities of our observables of interest and deviations from standard model can range from moderate to large depending on the [Formula: see text] value.

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Bailas, Gabriela, Benoît Blossier, Jochen Heitger, Vincent Morénas, and Matthias Post. "On the D*s and charmonia leptonic decays." EPJ Web of Conferences 175 (2018): 13002. http://dx.doi.org/10.1051/epjconf/201817513002.

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Among the different scenarios of New Physics, those with an extended Higgs sector are examined with a lot of attention. Recent experimental observations of several anomalies in flavour physics with respect to expectations of the Standard Model further motivate the effort of phenomenologists. First, informations about the RDs ratio, a test of lepton flavour universality equivalent to RD, already measured, but with the s quark as spectator, are awaited in coming years to constrain the corner of an extended Higgs sector with charged doublets. On another side, leptonic widths of pseudoscalar quarkonia are particularly interesting to test an extended Higgs sector with a light CP-odd Higgs boson singlet, through the study of its mixing with quarkonia states. Hadronic parameters entering those processes have to be determined from lattice QCD with enough confidence on the control of systematic errors. We report on the very first step of a long-term program tackled with Nf = 2 Wilson-Clover fermions to put relevant constraints on extensions of the Higgs sector: extraction of decay constants of D*s, ƞc, ƞc (2S), J/Ψ and Ψ(2S) with lattice ensembles provided by the CLS effort, considering 2 lattice spacings and a large range of pion masses to estimate cut-off effects and extrapolate results to the chiral limit.

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Schramm, Steven. "ATLAS Jet Reconstruction, Calibration, and Tagging of Lorentzboosted Objects." EPJ Web of Conferences 182 (2018): 02113. http://dx.doi.org/10.1051/epjconf/201818202113.

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Jet reconstruction in the ATLAS detector takes multiple forms, as motivated by the intended usage of the jet. Different jet definitions are used in particular for the study of QCD jets and jets containing the hadronic decay of boosted massive particles. These different types of jets are calibrated through a series of mostly sequential steps, providing excellent uncertainties, including a first in situ calibration of the jet mass scale. Jet tagging is investigated, including both not-top-quark vs gluon discrimination as well as W/Z boson, H → bb, and top-quark identification. This includes a first look at the use of Boosted Decision Trees and Deep Neural Networks built from jet substructure variables, as well as Convolutional Neural Networks built from jet images. In all cases, these advanced techniques are seen to provide gains over the standard approaches, with the magnitude of the gain depending on the use case. Future methods for improving jet tagging are briefly discussed, including jet substructure-oriented particle flow primarily for W/Z tagging and new subjet reconstruction strategies for H → bb tagging.

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Journal articles on the topic 'Hadronic decay study'

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