The observation of an anomalous J/psi suppression in Pb-Pb collisions by the NA50 Collaboration can be considered as the most striking indication for the deconfinement of quarks and gluons at SPS energies. In this Letter, we determine the J/psi suppression pattern as a function of the forward hadronic energy E-ZDC measured in a Zero Degree Calorimeter (ZDC). The direct connection between EZDC and the geometry of the collision allows us to calculate, within a Glauber approach, the precise relation between the number of participant nucleons N-part and E-ZDC. Then, we check if the experimental data can be better explained by a sudden or a smooth onset of the anomalous J/psi suppression as a function of the number of participants. (C) 2001 Elsevier Science B.V. All rights reserved. RI Santos, Helena/B-9141-2011; Alexa, Calin/F-6345-2010; Rato Mendes, Pedro/F-8827-2010; Cortese, Pietro/G-6754-2012; beole', stefania/G-9353-2012
The dependence of the anomalous J/psi suppression on the number of participant nucleons
DE FALCO, ALESSANDRO;PUDDU, GIOVANNA;USAI, GIANLUCA;
2001-01-01
Abstract
The observation of an anomalous J/psi suppression in Pb-Pb collisions by the NA50 Collaboration can be considered as the most striking indication for the deconfinement of quarks and gluons at SPS energies. In this Letter, we determine the J/psi suppression pattern as a function of the forward hadronic energy E-ZDC measured in a Zero Degree Calorimeter (ZDC). The direct connection between EZDC and the geometry of the collision allows us to calculate, within a Glauber approach, the precise relation between the number of participant nucleons N-part and E-ZDC. Then, we check if the experimental data can be better explained by a sudden or a smooth onset of the anomalous J/psi suppression as a function of the number of participants. (C) 2001 Elsevier Science B.V. All rights reserved. RI Santos, Helena/B-9141-2011; Alexa, Calin/F-6345-2010; Rato Mendes, Pedro/F-8827-2010; Cortese, Pietro/G-6754-2012; beole', stefania/G-9353-2012
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
