Skip to Main content Skip to Navigation
Theses

Etude de l'effet d'écrantage de couleur dans un plasma de quarks et de gluons sur les taux de production des quarkonia dans les collisions d'ions lourds auprès de l'expérience PHENIX.

Abstract : Relativistic heavy ion collisions may be used as a tool to produce the quark-gluon plasma (QGP), which is predicted to be the state of hadronic matter for temperatures larger than about 200~GeV. The $J/\psi$, a~$c\bar{c}$ bound state, is foreseen to be a sensitive probe of the QGP formation, which effects on the $J/\psi$ yield should compete with the cold nuclear matter (CNM) effects. An abnormal $J/\psi$ suppression (well in excess of the expected CNM effects) was previously seen by the NA50 (SPS) experiment in the most central Pb~+~Pb collisions. The PHENIX (RHIC) experiment carries on this study but with approximately ten times more energy. We studied the $J/\psi\to\mu^+\mu^-$ production in Cu~+~Cu collisions achieved in 2005 at 200~GeV energy per binary nucleon-nucleon collision. The obtained results bring sizeable information on the CNM effets: they significantly improve the measurement accuracy for a small number of participating nucleons per collision, for which the QGP can not be produced. They confirm the similarity of the suppression previously seen at RHIC in Au~+~Au and at SPS, this observation being still dependent of any future improvement of the CNM effects knowledge at RHIC. The combined Au~+~Au and Cu~+~Cu results can not be described by most theoretical predictions. They may favour the hypothesis of a secondary in-medium $J/\psi$ production (recombination models).
Document type :
Theses
Complete list of metadatas

Cited literature [117 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/pastel-00003165
Contributor : Ecole Polytechnique <>
Submitted on : Friday, July 23, 2010 - 2:44:30 PM
Last modification on : Wednesday, March 27, 2019 - 4:40:11 PM
Long-term archiving on: : Monday, October 25, 2010 - 11:11:36 AM

Identifiers

  • HAL Id : pastel-00003165, version 1

Collections

Citation

Andry Rakotozafindrabe. Etude de l'effet d'écrantage de couleur dans un plasma de quarks et de gluons sur les taux de production des quarkonia dans les collisions d'ions lourds auprès de l'expérience PHENIX.. Physique [physics]. Ecole Polytechnique X, 2007. Français. ⟨pastel-00003165⟩

Share

Metrics

Record views

301

Files downloads

577