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1. Quarkonium dynamics in the quantum Brownian regime with non-abelian quantum master equations

Author

Stéphane Delorme, Roland Katz, Thierry Gousset, Pol Bernard Gossiaux, and Jean-Paul Blaizot

Subjects
Finite Temperature or Finite Density, Quarkonium, Effective Field Theories of QCD, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We present numerical solutions in a one-dimensional setting of quantum master equations that have been recently derived. We focus on the dynamics of a single heavy quark-antiquark pair in a Quark-Gluon Plasma in thermal equilibrium, in the so-called quantum Brownian regime where the temperature of the plasma is large in comparison with the spacing between the energy levels of the Q Q ¯ $$ Q\overline{Q} $$ system. The one-dimensional potential used in the calculations has been adjusted so as to produce numbers that are relevant for the phenomenology of the charmonium. The equations are solved using different initial states and medium configurations. Various temperature regimes are studied and the effects of screening and collisions thoroughly analyzed. Technical features of the equations are analyzed. The contributions of the different operators that control the evolution are discussed as a function of the temperature. Some phenomenological consequences are addressed.

Published
2024
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2. Approach to the time development of parton fragmentation

Author

Martin, Rohrmoser, Pol-Bernard, Gossiaux, Thierry, Gousset, and Jörg, Aichelin

Subjects
High Energy Physics - Phenomenology
Abstract

It is the central goal of our studies to describe parton fragmentation in the hot and dense medium of a quark gluon plasma (QGP). Under the assumption that the medium is not static and homogeneous, knowledge about the temporal evolution of the processes involved can be of essential importance. Therefore, parton fragmentation has been studied with a Monte-Carlo algorithm that approximates the DGLAP-evolution of fragmentation functions via a set of parton cascades. The presented work consists mainly of implementations of this kind of algorithm and the application of a simple approximation, which gives the time development of partonic cascades. As approximations to the parton-splitting processes of gluons and massless quarks in the vacuum two different schemes with the same leading-log contributions are investigated. Furthermore, the temporal evolutions of quantities related to partonic cascades have been examined: To our understanding, especially variables (like, e.g.: parton multiplicities or virtualities) that give insight, when parton splittings take place, are of great interest, as they allow identifying the parts of the fragmentation process that will be most affected by medium interactions., Comment: part of the proceedings of the EPS-HEP 2015 conference in Vienna, 6 pages

Published
2015

3. Quarkonia dynamics in the QGP with open quantum systems

Author

Stéphane Delorme, Thierry Gousset, Roland Katz, Pol-Bernard Gossiaux, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Institut Mines-Télécom [Paris] (IMT)

Subjects
[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Physics, QC1-999, High Energy Physics::Phenomenology, 0103 physical sciences, 010306 general physics, 01 natural sciences, ComputingMilieux_MISCELLANEOUS
Abstract

We investigate the real-time dynamics of a correlated heavy quarkantiquark pair inside the Quark-Gluon Plasma using new quantum master equations derived from first QCD principles and based on the work of Blaizot & Escobedo [4]. The full equations are directly numerically solved in one-dimension to reduce computing costs and is used to gain insight on the dynamics in both a static and evolving medium following a Björken-like temperature evolution. The effect of the initial state on the dynamics is also studied.

Published
2022

4. Quarkonium dynamics inside the Quark-Gluon Plasma using open quantum systems

Author

Stéphane Delorme, Thierry Gousset, Roland Katz, Pol-Bernard Gossiaux, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Institut Mines-Télécom [Paris] (IMT)

Subjects
[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Physics, QC1-999, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS
Abstract

In recent years, a significant theoretical effort has been made towards a dynamical description of quarkonia inside the Quark-Gluon Plasma (QGP), using the open quantum systems formalism. In this framework, one can get a real-time description of a quantum system (here the quarkonium) in interaction with a thermal bath (the QGP) by integrating out the bath degrees of freedom and studying the system reduced density matrix. We investigate the real-time dynamics of a correlated heavy quark-antiquark pair inside the QGP using a quantum master equation previously derived from first QCD principles in [4]. The full equation is directly resolved in 1D to lessen computing costs and is used for the first time to gain insight on the dynamics in both a static and evolving medium following a Björken-like temperature evolution.

Published
2022

5. Effects of jet-medium interactions on angular correlations of jet-particle pairs at different energy scales

Author

Thierry Gousset, Martin Rohrmoser, P. B. Gossiaux, Joerg Aichelin, Iurii Karpenko, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST)

Subjects
Physics, correlation: two-particle, Jet (fluid), matter: interaction, jet: interaction, Radiant energy, FOS: Physical sciences, Observable, quantum chromodynamics: plasma, Nuclear physics, High Energy Physics - Phenomenology, jet: broadening, High Energy Physics - Phenomenology (hep-ph), jet: energy loss, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quark–gluon plasma, Radiative transfer, Particle, jet: angular correlation, Energy (signal processing), quark gluon: plasma, quantum chromodynamics: matter
Abstract

The energy-loss of hard probes within the hot and dense medium of a quark gluon plasma (QGP) can be described by theoretical models based on radiative energy loss as well as combinations of collisional and radiative energy loss. In a search for observables that allow to disentangle these energy-loss mechanisms, we introduced a set of effective models that allows to investigate the consequences on jets of both types of jet-medium interactions within a consistent framework. We particularly studied angular jet-broadening via angular two-particle correlations. Distinguishing contributions from pairs at different scales of particle momenta, we found qualitative differences between radiative and collisional approaches., Comment: proceedings for a seminar talk at the "Hard Probes 2018" conference in Aix Les Bains, 4 pages, 1 figure

Published
2018

6. Discrimination of effective radiative and collisional in-medium energy-loss models by their effects on angular jet structure

Author

Thierry Gousset, Jörg Aichelin, Pol Bernard Gossiaux, Martin Rohrmoser, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Laboratoire de physique subatomique et des technologies associées ( SUBATECH ), and IMT Atlantique Bretagne-Pays de la Loire ( IMT Atlantique ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Nantes ( UN )

Subjects
heavy ion: scattering, energy loss, FOS: Physical sciences, General Physics and Astronomy, Jet (particle physics), 01 natural sciences, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Radiative transfer, structure, 010306 general physics, Nuclear Experiment, quark gluon: plasma, Physics, particle: energy, 010308 nuclear & particles physics, Plasma, Computational physics, angular dependence, Automatic Keywords, High Energy Physics - Phenomenology, Medium energy, jet: production, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Particle, [ PHYS.HPHE ] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Heavy ion
Abstract

International audience; Energy-loss studies of hard particle probes produced in heavy ion collisions have often been used to get information on the interactions within the medium of a quark-gluon plasma (QGP). However, with the study of in-medium energy-loss of individual particles alone, it remains still ambiguous, whether the occured decrease in particle energy is caused by predominantly radiative or collisional energy-loss mechanisms. Focusing on the in-medium energy-loss of hard jet-partons, we propose additional studies of the angular jet-structure as a means to further constrain the energy-loss mechanisms.

Published
2018

7. Radiative energy loss in absorptive medium

Author

P. B. Gossiaux, Thierry Gousset, Alexandre Parent du Chatelet, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST)

Subjects
Quark, heavy ion: scattering, Nuclear Theory, emission: spectrum, energy spectrum, Parton, gluon: bremsstrahlung, Nuclear physics, Radiative transfer, Landau-Pomeranchuk-Migdal effect, Nuclear Experiment, Gluon field, quark gluon: plasma, Physics, High Energy Physics::Phenomenology, Bremsstrahlung, Radiant energy, parton: propagation, Gluon, particle: interaction, gluon: correlation function, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], State of matter, High Energy Physics::Experiment, parton: energy loss, formation: time
Abstract

International audience; Understanding the energy loss of strongly interacting particles is of utmost importance for studying the quark-gluon plasma (QGP). This very hot and dense state of matter is created during heavy-ion collisions, like the ones performed at the LHC. As the lifetime of the QGP is very brief, special probes are necessary to study it. One of them consists in focusing on the energy loss of energetic quarks or gluons (so-called partons) created in the early stages of the collision. These partons go through the QGP and are sensitive to all its development. One can then compare the energy spectrum of this kind of particles after going through the QGP or after going through usual nuclei and learn features of the QGP by comparison. For this it is important to master theoretically the energy loss of these partons. A particle can loose energy either by collisional processes (diffusion in the medium) or by radiative mechanisms (bremsstrahlung). The emission of a gluon takes a certain amount of time called the formation time. In the medium, this time can be longer than the mean free path of the particle leading to the LPM effect and a modification of the emission spectrum. But what if during its formation the gluon emits other gluons in turn. One phenomenological way to deal with this effect is to associate a damping rate to the first emitted gluon, and then investigate the consequences on its parent parton energy loss. In this presentation, we use the formalism developed in [6] to study the in-medium radiation by energetic quarks or gluons. In this formalism the propagation of a parton and its elastic scatterings with the medium is driven by a two-point correlator of the gluon field in the medium. We examine the modification of the two-point correlator for collisions that are accompanied by bremsstrahlung gluons that are sufficiently soft so as to be formed before the next interaction, and study whether this leads to a damping scenario.

Published
2017

9. Radio-detection signature of high-energy cosmic rays by the CODALEMA experiment

Author

Alain Lecacheux, Didier Charrier, Ferid Haddad, Thierry Gousset, Pascal Lautridou, P. Eschstruth, Olivier Ravel, D. Ardouin, Richard Dallier, D. Monnier-Ragaigne, A. Rahmani, A. Belletoile, J. Lamblin, L. Denis, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and CODALEMA

Subjects
Nuclear and High Energy Physics, Ultra-high-energy cosmic rays, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Data acquisition, 0103 physical sciences, Coherence (signal processing), Ultra-high-energy cosmic ray, Radio detection, 010306 general physics, Instrumentation, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Signature (logic), 95.55.Jz, 29.90.+r, 96.40-z, Microwave, Counting rate
Abstract

Taking advantage of recent technical progress which has overcome some of the difficulties encountered in the 1960's in the radio detection of extensive air showers induced by ultra high energy cosmic rays (UHECR), a new experimental apparatus (CODALEMA) has been built and operated. We will present the characteristics of this device and the analysis techniques that have been developed for observing electrical transients associated with cosmic rays. We find a collection of events for which both time and arrival direction coincidences between particle and radio signals are observed. The counting rate corresponds to shower energies $\geq 5\times 10^{16}$ eV. The performance level which has been reached considerably enlarges the perspectives for studying UHECR events using radio detection., merge of astro-ph/0504240 and astro-ph/0504297 into one paper

Published
2005

10. J/Ψproduction

Author

Thierry Gousset, François Arleo, Jörg Aichelin, and Pol Bernard Gossiaux

Subjects
Physics, Quantum chromodynamics, Particle physics, Proton, General Physics and Astronomy, Current (fluid)
Abstract

For more than 25 years J/ψ production has helped to sharpen our understanding of QCD. In proton induced reaction some observations are rather well understood while others are still unclear. The current status of the theory of J/ψ production will be sketched, paying special attention to the issues of formation time and J/ψre-interaction in a nuclear medium.

Published
2003

11. Heavy-quarkonium hadron interaction from a leading twist QCD analysis

Author

Jörg Aichelin, Pol Bernard Gossiaux, F. Arleo, Thierry Gousset, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, High energy, Particle physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Hadron, Quarkonium, 01 natural sciences, Nuclear physics, Cross section (physics), 0103 physical sciences, High Energy Physics::Experiment, Twist, Nuclear Experiment, 010306 general physics, Energy (signal processing)
Abstract

We discuss the leading twist QCD prediction of the heavy-quarkonium hadron cross section. The energy dependence of the J/ψ–proton cross section is computed. It turns out to be small in the vicinity of the threshold and smoothly increases at high energy.

Published
2002

12. Exclusive hadronization in

Author

Markus Diehl, Thierry Gousset, and Bernard Pire

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Photon, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, Atomic and Molecular Physics, and Optics, Hadronization, Matrix (mathematics), Amplitude, Pi, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment
Abstract

We perform a QCD analysis of exclusive two-meson production in gamma* gamma collisions in the kinematical domain of large photon virtuality Q^2 and small hadronic invariant mass W^2. In these kinematics the amplitude factorizes into a perturbative subprocess gamma* gamma -> q qbar and a two-meson distribution amplitude. This opens the way to study new hadronic matrix elements related with the physics of hadronization and confinement.

Published
2000

13. QCD factorization in γ*γ → ππ and γ*N → ππN

Author

Markus Diehl, Bernard Pire, Thierry Gousset, and O. V. Terayev

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, Virtual particle, Parton, 01 natural sciences, Pion, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, Perturbation theory (quantum mechanics), Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Exclusive two-pion production near threshold in the collision of a highly virtual photon with a real one offers a new possibility to unravel the partonic content of hadrons. We explain the dynamics of this regime, i.e. the separation of the amplitude in terms of partonic diagrams computable in QCD perturbation theory and generalized distribution amplitudes, which are nonperturbative functions describing the exclusive transition of a parton pair into two hadrons. The same quantities also appear in gamma* N -> pi pi N in the kinematical regime where the momentum transfer of the nucleon and the invariant mass of the pion pair are both small; this allows to extend the QCD analysis of exclusive rho electroproduction outside the resonance region of the two produced pions.

Published
1999

14. High-energy exclusive leptoproduction of vector mesons

Author

Thierry Gousset

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, FOS: Physical sciences, Virtual particle, Observable, HERA, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics::Experiment, Vector meson, Nuclear Experiment, Wave function, Nucleon
Abstract

The physics of diffractive vector meson production in virtual photon nucleon scattering at NMC energies is reviewed. A particular attention is paid to the physical aspects of the reaction and how they influence the observables. The reaction is a good probe to investigate both soft exchange mechanisms and hadronic wave functions. Extension to either HERA or ELFE kinematics is sketched out., Comment: Contribution to the workshop "ELFE at DESY" (St-Malo, Sep. 96), 15 pages, LaTeX file, 8 figures, uses epsf

Published
1997

15. Gluon radiation by heavy quarks

Author

P. B. Gossiaux, Thierry Gousset, Joerg Aichelin, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Quark, History, Particle physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, Parton, Radiation, 7. Clean energy, 01 natural sciences, Education, Nuclear physics, Cross section (physics), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Physics, Range (particle radiation), 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Plasma, Computer Science Applications, Gluon, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment
Abstract

The gluon emission cross section of a heavy quark colliding a light parton from the plasma is computed in pQCD at leading order. It is possible to compute the complete energy dependence of the result and therefore to assess the range of applicability in energy of standard high-energy approximation.

Published
2013

16. Gluon radiation by heavy quarks at intermediate energies

Author

Joerg Aichelin, Thierry Gousset, Pol Bernard Gossiaux, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), and Mines Nantes (Mines Nantes)

Subjects
Quark, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Strangeness production, FOS: Physical sciences, Omega baryon, 7. Clean energy, Gluon, Hadronization, Charm quark, Nuclear physics, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quark–gluon plasma, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Employing scalar QCD we study the gluon emission of heavy quarks created by the interaction with light quarks considered as dynamical scattering centers. We develop approximation formulas for the high-energy limit and study when the full calculation reaches this high-energy limit. For zero quark masses and in the high-energy limit our model reproduces the Gunion-Bertsch results. We justify why scalar QCD represents a good approximation to the full QCD approach for the energy loss of heavy quarks. In the regime of accessible phenomenology we observe that the emission at small transverse momentum (dead cone effect) is less suppressed than originally suggested. We also investigate the influence of a finite gluon mass on the discussed results.

Published
2013
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17. Radio detection of cosmic ray air showers by the CODALEMA experiment

Author

E. Morteau, L. Denis, O. Ravel, Alain Lecacheux, Ferid Haddad, Pascal Lautridou, C. Roy, Thierry Gousset, Richard Dallier, Carlo Rosolen, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and CODALEMA

Subjects
Electromagnetic field, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Radio equipment, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Radio telescope, Atmosphere, Air shower, 0103 physical sciences, Ultra-high-energy cosmic ray, 010306 general physics, Instrumentation, Electromagnetic pulse
Abstract

The possibilities of measuring Extremely High Energy Cosmic Rays (EHECR) by radio detection of electromagnetic pulses radiated during the development of extensive air showers in the atmosphere are investigated. We present the demonstrative CODALEMA experiment, set up at Nancay Radio-Observatory (France). The radio-decametric array has been adapted to measure radio transients in time coincidence between antennas., Comment: 4 pages, 4 figures, Proceedings of the 9th Pisa Meeting on Advanced Detectors, Isola d'Elba 2003, to be published in NIM A

Published
2004

18. Heavy quark quenching from RHIC to LHC and the consequences of gluon damping

Author

Pol Bernard Gossiaux, Thierry Gousset, Marlene Nahrgang, Marcus Bluhm, Joerg Aichelin, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Quark, Nuclear and High Energy Physics, Particle physics, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], High Energy Physics::Lattice, FOS: Physical sciences, 01 natural sciences, 7. Clean energy, Nuclear physics, Nuclear Theory (nucl-th), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, 010306 general physics, Nuclear Experiment, Quenching, Physics, Range (particle radiation), Large Hadron Collider, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Observable, Modification factor, Gluon, High Energy Physics - Phenomenology, Strange matter, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment
Abstract

In this contribution to the Quark Matter 2012 conference, we study whether energy loss models established for RHIC energies to describe the quenching of heavy quarks can be applied at LHC with the same success. We also benefit from the larger $p_T$-range accessible at this accelerator to test the impact of gluon damping on observables such as the nuclear modification factor., Comment: Proceedings of Quark Matter 2012 conference

Published
2012

19. Theory of heavy quark energy loss

Author

Joerg Aichelin, Thierry Gousset, P. B. Gossiaux, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
High Energy Physics - Theory, Quark, Physics, Quenching, Energy loss, Large Hadron Collider, Physics and Astronomy (miscellaneous), [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Ion, Nuclear physics, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment
Abstract

We briefly review some of the models and theoretical schemes established to describe heavy quark quenching in ultrarelativistic heavy ions collisions. Some lessons are derived from RHIC and early LHC data, especially as for the contraints they impose on those models., Comment: Proceeding from ISMD 2011 Conference, accepted for publication

Published
2012
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20. Geomagnetic origin of the radio emission from cosmic ray induced air showers observed by CODALEMA

Author

C. Fabrice, L. Denis, Benoît Revenu, X. Garrido, D. Breton, C. Dumez-Viou, A. Sourice, Pascal Lautridou, F. Meyer, K. Payet, F. Haddad, D.H. Koang, Nicole Meyer-Vernet, M. Chendeb, Didier Charrier, J. Chauvin, D. Monnier-Ragaigne, Thierry Gousset, François Lefeuvre, E. Meyer, S. Valcares, Lilian Martin, S. Dagoret-Campagne, O. Ravel, T. Saugrin, G. Plantier, A. Stutz, N. Gautherot, D. Lebrun, Corinne Berat, A. Cordier, Alain Lecacheux, F. Montanet, C. Riviere, T. Garcon, Richard Dallier, J. Lamblin, A. Bellétoile, P. Stassi, D. Ardouin, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), ESEO-GSII (GSII), ESEO-Tech, Université Bretagne Loire (UBL)-Université Bretagne Loire (UBL), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), CODALEMA, Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO)-Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
96.40.-z, Physics::Instrumentation and Detectors, 95.85.Ry, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, 01 natural sciences, Asymmetry, Particle detector, Ultra-High-Energy Cosmic Rays, Extensive Air showers, Observatory, 0103 physical sciences, Radio detection, 010306 general physics, media_common, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Air shower, Earth's magnetic field, 95.55.Jz, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Radio wave
Abstract

The new setup of the CODALEMA experiment installed at the Radio Observatory in Nancay, France, is described. It includes broadband active dipole antennas and an extended and upgraded particle detector array. The latter gives access to the air shower energy, allowing us to compute the efficiency of the radio array as a function of energy. We also observe a large asymmetry in counting rates between showers coming from the North and the South in spite of the symmetry of the detector. The observed asymmetry can be interpreted as a signature of the geomagnetic origin of the air shower radio emission. A simple linear dependence of the electric field with respect to vxB is used which reproduces the angular dependencies of the number of radio events and their electric polarity., Comment: 9 pages, 15 figures, 1 table

Published
2010

21. Radioelectric fields from cosmic-ray air showers at large impact parameters

Author

J. Lamblin, S. Valcares, Thierry Gousset, Laboratoire SUBATECH Nantes (SUBATECH), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astronomy and Astrophysics, Cosmic ray, Astrophysics, 01 natural sciences, Pulse (physics), Computational physics, Coherent radio emission:Radio detection:Extensive air showers:Cosmic-rays, Transverse plane, Electric field, 0103 physical sciences, Physical Sciences, Cutoff, Impact parameter, Current (fluid), 010303 astronomy & astrophysics, Radio detection, ComputingMilieux_MISCELLANEOUS
Abstract

We discuss electric fields generated by cosmic-ray air showers at large impact parameters b. An approximation relevant to this situation is given. The formulation makes explicit the relationship between the shower profile and the radio pulse shapes at large b, putting forward one important observational consequence, namely the decrease of the high-frequency cutoff ν c ∝ 1 / b 2 when the impact parameter increases. The approximation is also used to give a detailed comparison between two emission models, the geosynchrotron model and the transverse current model.

Published
2009

22. Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector

Author

Riviere, Colas, Ardouin, D., Belletoile, A., Berat, C., Breton, D., Charrier, D., Chauvin, J., Chendeb, M., Cordier, A., Dagoret-Campagne, S., Dallier, R., Denis, L., Dumez-Viou, C., Fabrice, C., Garcon, T., Garrido, X., Gautherot, N., Thierry Gousset, Haddad, F., Koang, D. H., Lamblin, J., Lautridou, P., Lebrun, D., Lecacheux, A., Lefeuvre, F., Martin, L., Meyer, E., Meyer, F., Meyer-Vernet, N., Monnier-Ragaigne, D., Montanet, F., Payet, K., Plantier, G., Ravel, O., Revenu, B., Riviere, C., Saugrin, T., Sourice, A., Stassi, P., Stutz, A., Valcares, S., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), CODALEMA, and Vernay, Emmanuelle

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), polarization, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], [SDU.ASTR.HE] Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, radio detection, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], [SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], CODALEMA, [PHYS.ASTR.IM] Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR.HE] Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]
Abstract

Cosmic rays extensive air showers (EAS) are associated with transient radio emission, which could provide an efficient new detection method of high energy cosmic rays, combining a calorimetric measurement with a high duty cycle. The CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is investigating this phenomenon in the 10^17 eV region. One challenging point is the understanding of the radio emission mechanism. A first observation indicating a linear relation between the electric field produced and the cross product of the shower axis with the geomagnetic field direction has been presented (B. Revenu, this conference). We will present here other strong evidences for this linear relationship, and some hints on its physical origin., Comment: Contribution to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009. 4 pages, 8 figures. v2: Typo fixed, arxiv references added

Published
2009
Full Text
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23. Prompt Photon Production in p-A Collisions at LHC and the Extraction of Gluon Shadowing

Author

Thierry Gousset, François Arleo, European Organization for Nuclear Research (CERN), Laboratoire SUBATECH Nantes (SUBATECH), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Particle physics, Large Hadron Collider, Photon, prompt photons, Physics::Instrumentation and Detectors, Nuclear shadowing, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Phenomenology, Extraction (chemistry), proton-nucleus collisions, Gluon
Abstract

International audience; A report is given on the study of using prompt photon production at the LHC to probe the gluon nuclear density, and more specifically the shadowing ratio GA/Gp that one could access in foreseen p-A runs.

Published
2007

24. Energy loss of a heavy quark produced in a finite-size quark-gluon plasma

Author

Stéphane Peigné, Christina Brandt, Pol Bernard Gossiaux, Thierry Gousset, Jörg Aichelin, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Physics, Quark, Nuclear and High Energy Physics, Particle physics, Energy loss, Opacity, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, Plasma, 01 natural sciences, Zeroth order, Nuclear physics, symbols.namesake, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Transition radiation, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Quark–gluon plasma, symbols, 010306 general physics, Debye length
Abstract

We study the energy loss of an energetic heavy quark produced in a high temperature quark-gluon plasma and travelling a finite distance before emerging in the vacuum. While the retardation time of purely collisional energy loss is found to be of the order of the Debye screening length, we find that the contributions from transition radiation and the Ter-Mikayelian effect do not compensate, leading to a reduction of the zeroth order (in an opacity expansion) energy loss., QM2006 Proceedings; caption of fig 1 and ref [7] modified in v2

Published
2006

25. An active dipole for cosmic ray radiodetection with CODALEMA

Author

Pascal Lautridou, S. Valcares, Alain Lecacheux, Richard Dallier, O. Ravel, Thierry Gousset, Didier Charrier, Ferid Haddad, D. Ardouin, A. Belletoile, L. Denis, T. Saugrin, J. Lamblin, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Franco Cervelli, Francesco Forti, Riccardo Paoletti and Angelo Scribano, CODALEMA, Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], 010308 nuclear & particles physics, Broad bandwidth, business.industry, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Astrophysics, 01 natural sciences, Dipole, Optics, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Spiral (railway), Electric pulse, 010306 general physics, business, Instrumentation, Radio detection, Electromagnetic pulse
Abstract

A paraître dans NIM A; International audience; The CODALEMA experiment detects the electromagnetic pulses radiated during the development of Extensive Air Showers (EAS). Since 2005, in addition to spiral log-periodic antennas, ultra broad bandwidth active dipoles have been designed to detect the full electric pulse shape of these signals. A few performances of these new detectors are presented.

Published
2006

26. Radioelectric Field Features of Extensive Air Showers Observed with CODALEMA

Author

O. Ravel, Ferid Haddad, Didier Charrier, S. Valcares, Thierry Gousset, Pascal Lautridou, T. Saugrin, J. Lamblin, D. Ardouin, Alain Lecacheux, A. Belletoile, D. Monnier-Ragaigne, L. Denis, Richard Dallier, P. Eschstruth, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), CODALEMA, Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Field (physics), Ultra-high-energy cosmic rays, FOS: Physical sciences, Magnitude (mathematics), Cosmic ray, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Electric field, 0103 physical sciences, Ultra-high-energy cosmic ray, Radio detection, 010306 general physics, Physics, 9640-z, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Ultra High Energy Cosmic Rays PACS: 9555Jz, Astrophysics (astro-ph), Astronomy and Astrophysics, 9585Ry, Computational physics, Core (optical fiber), 13. Climate action, Event (particle physics), Energy (signal processing)
Abstract

Based on a new approach to the detection of radio transients associated with extensive air showers induced by ultra high energy cosmic rays, the experimental apparatus CODALEMA is in operation, measuring about 1 event per day corresponding to an energy threshold ~ 5. 10^16 eV. Its performance makes possible for the first time the study of radio-signal features on an event-by-event basis. The sampling of the magnitude of the electric field along a 600 meters axis is analyzed. It shows that the electric field lateral spread is around 250 m (FWHM). The possibility to determine with radio both arrival directions and shower core positions is discussed., Accepted for publication in Astroparticle Physics

Published
2006

27. Retardation Effect for Collisional Energy Loss of Hard Partons Produced in a QGP

Author

Pol Bernard Gossiaux, Thierry Gousset, Stéphane Peigné, Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Physics, Nuclear and High Energy Physics, Energy loss, Particle physics, 010308 nuclear & particles physics, Electromagnetic spectrum, High Energy Physics::Phenomenology, Bremsstrahlung, FOS: Physical sciences, Parton, Plasma, 01 natural sciences, Gluon, Nuclear physics, Acceleration, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Physics::Plasma Physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Plasmon
Abstract

We study the collisional energy loss suffered by an energetic parton travelling the distance L in a high temperature quark-gluon plasma and initially produced in the medium. We find that the medium-induced collisional loss -Delta E(L) is strongly suppressed compared to previous estimates which assumed the collisional energy loss rate -dE/dx to be constant. The large L linear asymptotic behaviour of -Delta E(L) sets in only after a quite large retardation time. The suppression of -Delta E(L) is partly due to the fact that gluon bremsstrahlung arising from the initial acceleration of the energetic parton is reduced in the medium compared to vacuum. The latter radiation spectrum is sensitive to the plasmon modes of the quark-gluon plasma and has a rich angular structure., 19 pages, 4 figures. Substantial changes have been made in version 2, especially in section 3. In particular, in section 3.2 the dependence on a spurious ultraviolet cut-off has been removed. As a consequence numerical results are quantitatively modified, but the retardation effect is qualitatively unchanged. The physical origin of the largeness of the retardation time is also emphasized, and two Appendices have been added

Published
2005

28. Radio Detection of Extensive Air Showers with CODALEMA

Author

Ardouin, D., Belletoile, A., Didier Charrier, Richard Dallier, Loic Denis, Eschstruth, P., Thierry Gousset, Fayrouz. Haddad, Lamblin, J., Pascal Lautridou, Lecacheux, A., Monnier-Ragaigne, D., Ravel, O., Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Girod, Dominique

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics
Abstract

The principle and performances of the CODALEMA experimental device, set up to study the possibility of high energy cosmic rays radio detection, are presented. Radio transient signals associated to cosmic rays have been identified, for which arrival directions and shower's electric field topologies have been extracted from the antenna signals. The measured rate, about 1 event per day, corresponds to an energy threshold around 5.10^16 eV. These results allow to determine the perspectives offered by the present experimental design for radiodetection of UHECR at a larger scale., 4 pages and 3 figures. To appear in the Proceedings of the 29th ICRC, Pune (2005)

Published
2005

29. CODALEMA: a cosmic ray air shower radio detection experiment

Author

Pascal Lautridou, J. Lamblin, P. Eschstruth, A. Belletoile, D. Monnier-Ragaigne, Olivier Ravel, Didier Charrier, L. Denis, D. Ardouin, Alain Lecacheux, Thierry Gousset, Ferid Haddad, Richard Dallier, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and CODALEMA

Subjects
Physics, Nuclear and High Energy Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Atomic and Molecular Physics, and Optics, 030218 nuclear medicine & medical imaging, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 03 medical and health sciences, 0302 clinical medicine, Air shower, Electric field, 0103 physical sciences, Ultra-high-energy cosmic ray, Antenna (radio), 010306 general physics, Event (particle physics), Radio detection, Energy (signal processing)
Abstract

The CODALEMA experimental device currently detects and characterizes the radio contribution of cosmic ray air showers : arrival directions and electric field topologies of radio transient signals associated to cosmic rays are extracted from the antenna signals. The measured rate, about 1 event per day, corresponds to an energy threshold around 5.1016eV. These results allow to determine the perspectives offered by the present experimental design for radiodetection of Ultra High Energy Cosmic Rays at a larger scale.

Published
2005

30. Radiodetection of Cosmic Ray Extensive Air Showers: upgrade of the CODALEMA experiment

Author

Didier Charrier, P. Eschstruth, F. Haddad, D. Monnier-Ragaiggne, Richard Dallier, Thierry Gousset, Pascal Lautridou, Alain Lecacheux, O. Ravel, D. Ardouin, L. Denis, J. Lamblin, A. Rahmani, A. Belletoile, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), CODALEMA, Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Cosmic ray, Astrophysics, ultra high energy cosmic rays, 01 natural sciences, Atomic and Molecular Physics, and Optics, Coincidence, Antenna array, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Sky, 0103 physical sciences, Transient (oscillation), Antenna (radio), 010303 astronomy & astrophysics, Energy (signal processing), radiodetection, media_common
Abstract

International audience; We present the characteristics and performance of a demonstration experiment devoted to the observation of ultra high- energy cosmic ray extensive air showers using a radiodetection technique. In a first step, one antenna narrowed band filtered acting as trigger, with a 4 sigma threshold above sky background-level, was used to tag any radio transient in coincidence on the antenna array. Recently, the addition of 4 particle detectors has allowed us to observe cosmic ray events in coincidence with antennas.

Published
2004

31. Radio Detection of Cosmic Ray Extensive Air Showers: present status of the CODALEMA experiment

Author

Ardouin, D., Belletoile, A., Charrier, D., Dallier, Richard, Denis, L., Eschstruth, P., Thierry Gousset, Haddad, F., Lautridou, P., Lecacheux, A., Monnier-Ragaigne, D., Rahmani, A., Ravel, O., Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], radiodetection of cosmic ray air showers, CODALEMA, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics, cosmic ray
Abstract

Data acquisition and analysis for the CODALEMA experiment, in operation for more than one year, has provided improved knowledge of the characteristics of this new device. At the same time, an important effort has been made to develop processing techniques for extracting transient signals from data containing interference., Comment: september 2004

Published
2004
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32. Are vertical cosmic rays the most suitable to radio detection ?

Author

Christelle Roy, Thierry Gousset, Olivier Ravel, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and CODALEMA

Subjects
Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, radio telescopes and instrumentation, Cosmic ray, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Shower, cosmic rays, Electric field, 0103 physical sciences, Observation point, Radiation mechanisms, extensive air showers, Ultra-high-energy cosmic ray, 010303 astronomy & astrophysics, Physics, 95.30.Gv, 95.55.Jz, 96.40.Pq, 98.70.Sa, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Polarization (waves), High Energy Physics::Experiment, Impact parameter, Radio detection
Abstract

The electric field induced by extensive air showers generated by high energy cosmic rays is considered and, more specifically, its dependence on the shower incident angle. It is shown that for distances between the shower axis and the observation point larger than a few hundred meters, non-vertical showers produce larger fields than vertical ones. This may open up new prospects since, to some extent, the consideration of non-vertical showers modifies the scope of the radio-detection domain., Comment: 8 pages, 4 figures

Published
2004

33. Radio Detection of Cosmic Ray Extensive Air Showers

Author

Richard Dallier, Loic Denis, Thierry Gousset, Fayrouz. Haddad, Pascal Lautridou, Lecacheux, A., Morteau, E., Ravel, O., Rosolen, C., Roy, C., Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), F. Combes, D. Barret and T. Contini, CODALEMA, Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Dallier, Richard

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph]
Abstract

International audience; At the Radio Observatory of Nancay we study the possibility of detecting extremely high energy cosmic rays by radio detection of the electromagnetic pulse radiated during the development of extensive air showers in the atmosphere. Details on the experimental setup and present results on the demonstrative experiment CODALEMA are given.

Published
2003

34. Heavy-quarkonium hadron cross section in QCD at leading twist

Author

François Arleo, Jörg Aichelin, Thierry Gousset, Pol Bernard Gossiaux, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Hadron, High Energy Physics::Phenomenology, FOS: Physical sciences, Quarkonium, 01 natural sciences, Nuclear physics, Scattering amplitude, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Pion, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, Sum rule in quantum mechanics, Operator product expansion, Twist, 010306 general physics, Nuclear Experiment
Abstract

We compute the total cross section of a heavy quarkonium on a hadron target in leading twist QCD, including target mass corrections. Our method relies on the analytical continuation of the operator product expansion of the scattering amplitude, obtained long ago by Bhanot and Peskin. The cross section has a simple partonic form, which allows us to investigate the phenomenology of J/psi and Upsilon dissociation by both pions and protons., 21 pages, 4 figures, REVTeX4. Discussion of the scale dependence extended

Published
2002

35. γ[sup ∗]γ→ππ at large Q[sup 2]

Author

Markus Diehl, Thierry Gousset, and Bernard Pire

Subjects
Quantum chromodynamics, Physics, Particle physics, Photon, Meson, High Energy Physics::Phenomenology, Hadron, Observable, symbols.namesake, Pion, symbols, Feynman diagram, High Energy Physics::Experiment, Perturbation theory (quantum mechanics)
Abstract

The QCD analysis of the process γ*γ→ππ at large Q2 and small center-of-mass energy allows one to access a new hadronic observable describing the exclusive transition from a qq or gg state to a pair of mesons. A fruitful study may be envisaged at existing machines.

Published
2001

36. Exclusive production of pion pairs in γ*γ collisions at large Q2

Author

M. Diehl, Thierry Gousset, and Bernard Pire

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Partial wave analysis, High Energy Physics::Phenomenology, Hadron, Photon structure function, B-factory, Nuclear physics, Pion, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment
Abstract

We perform a QCD analysis of the exclusive production of two mesons in ${\mathrm{\ensuremath{\gamma}}}^{\mathrm{*}}$\ensuremath{\gamma} collisions in the kinematical domain of large photon virtuality Q and small hadronic invariant mass W. This reaction is dominated by a scale invariant mechanism which factorizes into a perturbative subprocess ${\ensuremath{\gamma}}^{*}\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}q\overline{q}$ or ${\ensuremath{\gamma}}^{*}\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}\mathrm{gg}$ and a generalized two-meson distribution amplitude. We develop in detail the phenomenology of this process at ${e}^{+}{e}^{\ensuremath{-}}$ colliders. Using a simple model for the two-pion distribution amplitude, based on its general properties, we estimate the cross section for the kinematics accessible at BABAR, BELLE, CLEO, and CERN LEP.

Published
2000

37. Charmonium suppression in p-A collisions

Author

F. Arleo, Jörg Aichelin, Pol Bernard Gossiaux, Thierry Gousset, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Octet, 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, State (functional analysis), Radius, 7. Clean energy, 01 natural sciences, Gluon, Nuclear physics, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, High Energy Physics::Experiment, Absorption (logic), Fermilab, Singlet state, 010306 general physics, Nuclear Experiment, Scaling
Abstract

The new high precision data on charmonium production in proton-nucleus collisions by the E866/NuSea collaboration at Fermilab allow - together with older data at lower energies - to fix a unique set of parameters for the standard production and absorption scenario of charmonium in a proton-nucleus reaction. In this scenario the c-cbar pair is formed in an octet state, emits a gluon and continues its radial expansion in a singlet state until it has reached the charmonium radius. In all three phases it can interact with the nuclear environment. We find that the lifetime of the octet state is much shorter than acceptable on physical grounds. This challenges the physical reality of the first phase in the standard scenario., Comment: 8 pages, 10 figures

Published
1999
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38. Exclusive electroproduction of vector mesons and transversity distributions

Author

Thierry Gousset, Markus Diehl, Bernard Pire, Laboratoire SUBATECH Nantes (SUBATECH), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, 01 natural sciences, High Energy Physics - Phenomenology, Distribution (mathematics), High Energy Physics - Phenomenology (hep-ph), Factorization, 0103 physical sciences, High Energy Physics::Experiment, Vector meson, Perturbation theory (quantum mechanics), Twist, 010306 general physics, Nucleon, Nuclear Experiment
Abstract

We show that the leading twist contribution to exclusive electroproduction of transversely polarized vector mesons vanishes at all orders in perturbation theory. Therefore one cannot extract information on the quark transversity distribution of the nucleon from this reaction. In turn one has that the produced vector meson is purely longitudinal in the large-Q^2 limit, which provides a new test of the dominance of leading twist at finite Q^2., Comment: 8 pages, 2 figures

Published
1998
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39. Time ordering in off-diagonal parton distributions

Author

Markus Diehl, Thierry Gousset, Laboratoire SUBATECH Nantes (SUBATECH), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Diagonal, High Energy Physics::Phenomenology, FOS: Physical sciences, Parton, 01 natural sciences, Interpretation (model theory), High Energy Physics - Phenomenology, Distribution (mathematics), High Energy Physics - Phenomenology (hep-ph), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Point (geometry), High Energy Physics::Experiment, 010306 general physics, Link (knot theory), Nuclear Experiment
Abstract

We investigate the relevance of time ordering in the definition of off-diagonal parton distributions in terms of products of fields. The method we use easily allows determination of their support properties and provides a link to their interpretation from a parton point of view. It can also readily be applied to meson distribution amplitudes.}, Comment: 15 pages with 3 figures

Published
1998
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40. Collisional and Radiative Energy Loss of Heavy Quarks

Author

Thierry Gousset, Pol Bernard Gossiaux, J Aichelin, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Physics, Quark, Quantum chromodynamics, History, Energy loss, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Scalar (mathematics), Radiant energy, Context (language use), Plasma, 01 natural sciences, Computer Science Applications, Education, Nuclear physics, Physics::Plasma Physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Radiative transfer, Nuclear Experiment, 010306 general physics, ComputingMilieux_MISCELLANEOUS
Abstract

Heavy quarks are one of the key tools to study the properties of the expanding plasma created in ultrarelativistic heavy ion collisions. In this context we develop a framework to study the Qq → Qqg collsions in scalar QCD and provide the results for different key quantities. We investigate the radiative energy loss and compare the results to the the collisional energy loss. We conclude that radiative and collisional energy loss together allow for a description of the recently published ALICE data.

Published
2013

41. Hadron helicity violation in exclusive processes: Quantitative calculations in leading order QCD

Author

John P. Ralston, Bernard Pire, and Thierry Gousset

Subjects
Quantum chromodynamics, Quark, Physics, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Angular momentum, Momentum transfer, Hadron, FOS: Physical sciences, Helicity, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Symmetry breaking
Abstract

We study a new mechanism for hadronic helicity flip in high energy hard exclusive reactions. The mechanism proceeds in the limit of perfect chiral symmetry, namely without any need to flip a quark helicity. The fundamental feature of the new mechanism is the breaking of rotational symmetry of the hard collision by a scattering plane in processes involving independent quark scattering. We show that in the impulse approximation there is no evidence for of the helicity violating process as the energy or momentum transfer $Q^2$ is increased over the region 1 GeV^2 < Q^2 < 100 GeV^2. In the asymptotic region Q^2> 1000 GeV^2, a saddle point approximation with doubly logarithmic accuracy yields suppression by a fraction of power of Q^2. ``Chirally--odd" exclusive wave functions which carry non--zero orbital angular momentum and yet are leading order in the high energy limit, play an important role., uuencoded LaTeX file (21 pages) and PostScript figures

Published
1996

42. [Untitled]

Author

Marcus Bluhm, Thierry Gousset, Joerg Aichelin, and Pol Bernard Gossiaux

Subjects
Quark, Physics, 010308 nuclear & particles physics, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Bremsstrahlung, General Physics and Astronomy, Radiant energy, Plasma, Radiation, 01 natural sciences, 7. Clean energy, Spectral line, Gluon, Nuclear physics, 0103 physical sciences, Quark–gluon plasma, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract

In an absorptive plasma, damping of radiation mechanisms can influence the bremsstrahlung formation in case of large radiation formation lengths. We study qualitatively the influence of this effect on the gluon bremsstrahlung spectrum off heavy quarks in the quark-gluon plasma. Independent of the heavy-quark mass, the spectrum is found to be strongly suppressed in an intermediate gluon energy region which grows with increasing gluon damping rate and increasing energy of the heavy quark. Thus, just as polarization effects in the plasma render the bremsstrahlung spectra independent of the quark mass in the soft gluon regime, damping effects tend to have a similar impact for larger gluon energies.

Published
2012

43. Timelike form factors at high energy

Author

Bernard Pire and Thierry Gousset

Subjects
Quantum chromodynamics, Physics, Particle physics, Meson, High Energy Physics::Phenomenology, Perturbative QCD, FOS: Physical sciences, Elementary particle, High Energy Physics - Phenomenology, General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology (hep-ph), Gravitational singularity, Perturbation theory (quantum mechanics), Mathematics::Differential Geometry, Constant (mathematics), Boson, Mathematical physics
Abstract

The difference between the timelike and spacelike meson form factors is analysed in the framework of perturbative QCD with Sudakov effects included. It is found that integrable singularities appear but that the asymptotic behavior is the same in the timelike and spacelike regions. The approach to asymptotia is quite slow and a rather constant enhancement of the timelike value is expected at measurable large \(Q^{2}\). This is in agreement with the trend shown by experimental data., Comment: 17 pages, report DAPNIA/SPhN 94 09

Published
1994
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44. Competition of heavy quark radiative and collisional energy loss in deconfined matter

Author

Vincent Guiho, Pol Bernard Gossiaux, Thierry Gousset, Jörg Aichelin, Laboratoire SUBATECH Nantes (SUBATECH), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes)

Subjects
Physics, Quark, Nuclear and High Energy Physics, Particle physics, Energy loss, 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, Radiant energy, Modification factor, Electron, 01 natural sciences, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Quark–gluon plasma, Radiative transfer, Nuclear Experiment, 010306 general physics
Abstract

We extend our recently advanced model on collisional energy loss of heavy quarks in a quark gluon plasma (QGP) by including radiative energy loss. We discuss the approach and present first preliminary results. We show that present data on nuclear modification factor of non photonic single electrons hardly permit to distinguish between those 2 energy loss mechanisms., 8 pages, extended to 11 pages for v2; accepted for publication in Journal of Physics G

Published
2010

45. Measuring gluon shadowing with prompt photons at RHIC and LHC

Author

François Arleo, Thierry Gousset, European Organization for Nuclear Research (CERN), Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire SUBATECH Nantes (SUBATECH), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Particle physics, Proton, Nuclear shadowing, Nuclear Theory, FOS: Physical sciences, Parton, Prompt photons, 7. Clean energy, 01 natural sciences, Nuclear physics, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Rapidity, 010306 general physics, Nuclear Experiment, Particle Physics - Phenomenology, Physics, Quantum chromodynamics, 010308 nuclear & particles physics, Proton–nucleus collisions, High Energy Physics::Phenomenology, Perturbative QCD, Gluon, High Energy Physics - Phenomenology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, Nucleon, Nuclear density
Abstract

The possibility to observe the nuclear modification of the gluon distribution at small-x (gluon shadowing) using high-p_T prompt photon production at RHIC and at LHC is discussed. The per-nucleon ratio, sigma(p+A -> gamma+X) / A sigma(p+p -> gamma+X), is computed for both inclusive and isolated prompt photons in perturbative QCD at NLO using different parametrizations of nuclear parton densities, in order to assess the visibility of the shadowing signal. The production of isolated photons turns out to be a promising channel which allows for a reliable extraction of the gluon density, G^A/G^p, and the structure function, F_2^A/F_2^p, in a nucleus over that in a proton. Moreover, the production ratio of prompt photons at forward-over-backward rapidity in p-A collisions provides an estimate of G^A/G^p (at small x) over F_2^A/F_2^p (at large x), without the need of p-p reference data at the same energy., 14 pages, 6 figures. Typo corrected in Eq. (4)

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46. Testing the handbag contribution to exclusive virtual Compton scattering

Author

Markus Diehl, Thierry Gousset, Bernard Pire, and John P. Ralston

Subjects
Physics, Nuclear and High Energy Physics, Angular momentum, Particle physics, Nuclear Theory, Hadron, Compton scattering, FOS: Physical sciences, Measure (mathematics), Nuclear Theory (nucl-th), Cross section (physics), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Focus (optics), Event (particle physics), Lepton
Abstract

We discuss the handbag approximation to exclusive deep virtual Compton scattering. After defining the kinematical region where this approximation can be valid, we propose tests for its relevance in planned electroproduction experiments, e + p -> e + p + gamma. We focus on scaling laws in the cross section, and the distribution in the angle between the lepton and hadron planes, which contains valuable information on the angular momentum structure of the Compton process. We advocate to measure weighted cross sections, which make use of the data in the full range of this angle and do not require very high event statistics., 14 pages, LaTeX, 3 figures included using epsf.sty

47. Probing gluon shadowing with forward photons at RHIC

Author

Arleo, Francois, Thierry Gousset, Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire SUBATECH Nantes (SUBATECH), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear Theory (nucl-th), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Nuclear Theory, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

There is a major need to better constrain nuclear parton densities in order to provide reliable perturbative QCD predictions at the LHC as well as to probe possible non-linear evolution at small values of x. In these proceedings, we discuss how the production of prompt photons at large rapidity in p-p and d-Au collisions at RHIC (sqrt(s_NN)=200 GeV) is sensitive to the nuclear modifications of gluon distributions at x~0.001 and at rather low scales, Q^2~10 GeV^2. The nuclear production ratio, R_dAu=sigma(d+A->gamma+X)/(2A sigma(p+p->gamma X), is computed for isolated prompt photons at NLO using the nDSg nuclear parton densities, in order to assess the visibility of the signal. We also emphasise that the expected counting rates in a year of running at RHIC are large, indicating that R_dAu could be measured with a high statistical accuracy., 4 pages. Talk given at Quark Matter 2008, Jaipur (India), February 4-10, 2008. Figure 2 replaced

49. QCD et les processus exclusifs durs (QCD and hard exclusive processes)

Author

Thierry Gousset and Pire, Bernard

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics::Lattice, High Energy Physics::Phenomenology, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract

We review the theory of hard exclusive reactions in QCD., Comment: in french , no figures attached, lecture given at the 27th summer school on particle physics, Clermont-Ferrand, France, 17-21 september 1995

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