Publications (35)
Non-universality of transverse Coulomb exchange at small x
J. Aichelin, F. Arleo, P. -B. Gossiaux +3
Within an explicit scalar QED model we compare, at fixed x << 1, the leading-twist K_T-dependent `quark' distribution f_q(x, K_T) probed in deep inelastic scattering and Drell-Yan…
Energy loss of a heavy quark produced in a finite-size quark-gluon plasma
P. B. Gossiaux, J. Aichelin, C. Brandt +2
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 ret…
Radioelectric Field Features of Extensive Air Showers Observed with CODALEMA
D. Ardouin, A. Belletoile, D. Charrier +12
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…
Exclusive electroproduction and off-diagonal parton distributions
M. Diehl, T. Gousset, B. Pire
Off-diagonal parton distributions occur in several hard exclusive reactions. They extend the study of hadron structure beyond what can be learned from ordinary distributions and ha…
Radio-Detection Signature of High Energy Cosmic Rays by the CODALEMA Experiment
D. Ardouin, A. Bellétoile, D. Charrier +11
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…
QCD et les processus exclusifs durs (QCD and hard exclusive processes)
T. Gousset, B. Pire
We review the theory of hard exclusive reactions in QCD.
Features of radio-detected Extensive Air Shower with CODALEMA
D. Ardouin, A. Belletoile, D. Charrier +9
Some performances of the present CODALEMA experiment, set up to analyse radio-detected Extensive Air Shower (EAS) events, are presented. Characteristics of the EAS electric field d…
Energy loss and scaling breakdown in nuclear production
F. Arleo, P. -B. Gossiaux, T. Gousset +1
In addition to the final-state interactions, nuclear production might also be affected by parton energy loss. Using the upper limits from Drell-Yan data at SPS and Fermilab…
The Ratio of Gluon Distributions in Sn and C
T. Gousset, H. J. Pirner
We calculate the ratio of gluon densities, G^Sn(x)/G^C(x), for 0.01<x<0.1, from the new high statistics data on F_2^Sn/F_2^C taken by the NM Collaboration. For small x, the shadowi…
Deeply Virtual Compton Scattering: How to Test Handbag Dominance?
M. Diehl, T. Gousset, B. Pire +1
We propose detailed tests of the handbag approximation in exclusive deeply virtual Compton scattering. Those tests make no use of any prejudice about parton correlations in the pro…
Timelike form factors at high energy
T. Gousset, B. Pire
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 sin…
QCD factorization in gamma* gamma -> pi pi and gamma* N -> pi pi N
M. Diehl, T. Gousset, B. Pire +1
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 exp…
Hadron Helicity Violation in Exclusive Processes: Quantitative Calculations in Leading Order QCD
T. Gousset, B. Pire, J. P. Ralston
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…
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
Colas Riviere, D. Ardouin, A. Belletoile +38
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…
Testing the handbag contribution to exclusive virtual Compton scattering
M. Diehl, T. Gousset, B. Pire +1
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…
Probing partonic structure in gamma* gamma -> pi pi near threshold
M. Diehl, T. Gousset, B. Pire +1
Hadron pair production gamma* gamma -> h hbar in the region where the c.m. energy is much smaller than the photon virtuality can be described in a factorized form, as the convoluti…
Heavy-quarkonium hadron cross section in QCD at leading twist
F. Arleo, P. -B. Gossiaux, T. Gousset +1
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 continuatio…
Vector meson leptoproduction and nonperturbative gluon fluctuations in QCD
H. G. Dosch, T. Gousset, G. Kulzinger +1
We present a nonperturbative QCD calculation of diffractive vector meson production in virtual photon nucleon scattering at high energy. We use the nonperturbative model of the sto…
Radiodetection of Cosmic Ray Extensive Air Showers
D. Ardouin, A. Belletoile, D. Charrier +12
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 radiodetectio…
Are vertical cosmic rays the most suitable to radio detection ?
T. Gousset, O. Ravel, C. Roy
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 sh…
Charmonium suppression in p-A collisions
F. Arleo, P. -B. Gossiaux, T. Gousset +1
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 - t…
Radio Detection of Cosmic Ray Air Showers with Codalema
D. Ardouin, A. Belletoile, D. Charrier +10
Studies of the radio detection of Extensive Air Showers is the goal of the demonstrative experiment CODALEMA. Previous analysis have demonstrated that detection around …
Geomagnetic origin of the radio emission from cosmic ray induced air showers observed by CODALEMA
D. Ardouin, A. Belletoile, C. Berat +37
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 upgrad…
Radio Detection of Cosmic Ray Extensive Air Showers: present status of the CODALEMA experiment
A. Belletoile, D. Ardouin, D. Charrier +10
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 sa…
Non-diagonal parton distribution functions
M. Diehl, T. Gousset
We explain why the time ordering in the definition of non-diagonal parton distributions can be omitted and discuss the physics implications.
Radio Detection of Extensive Air Showers with CODALEMA
D. Ardouin, A. Belletoile, D. Charrier +10
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 signa…
Competition of Heavy Quark Radiative and Collisional Energy Loss in Deconfined Matter
P. B. Gossiaux, J. Aichelin, T. Gousset +1
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 prese…
Polarisation in deeply virtual meson production
M. Diehl, T. Gousset, B. Pire
We discuss two aspects of polarisation in hard exclusive meson production: the leading-twist selection rule for the meson helicity, and the different partial waves of a (pi pi)-pai…
Time ordering in off-diagonal parton distributions
M. Diehl, T. Gousset
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 o…
Evidence for Radio Detection of Extensive Air Showers Induced by Ultra High Energy Cosmic Rays
D. Ardouin, A. Bellétoile, D. Charrier +10
Firm evidence for a radio emission counterpart of cosmic ray air showers is presented. By the use of an antenna array set up in coincidence with ground particle detectors, we find…
Exclusive hadronization in gamma* gamma -> pi pi
M. Diehl, T. Gousset, B. Pire
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^…
Nonperturbative γ^* p Interaction in the Diffractive Regime
H. G. Dosch, T. Gousset, H. J. Pirner
One of the challenging aspects of electroproduction at high-energy is the understanding of the transition from real photons to virtual photons in the GeV^2 region. We study inclusi…
Retardation Effect for Collisional Energy Loss of Hard Partons Produced in a QGP
S. Peigne, P. -B. Gossiaux, T. Gousset
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 fin…
Radio Detection of Cosmic Ray Air Shower by the CODALEMA Experiment
O. Ravel, R. Dallier, L. Denis +7
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 th…
Radiative and Collisional Energy Loss of Heavy Quarks in Deconfined Matter
J. Aichelin, P. B. Gossiaux, T. Gousset
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 prese…