# The dependence of the anomalous $J/\psi$ suppression on the number of participant nucleons

6 ALICE
IP2I Lyon - Institut de Physique des 2 Infinis de Lyon
Abstract : The observation of an anomalous \jpsi\ suppression in \mbox{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 \jpsi\ suppression pattern as a function of the forward hadronic energy \ezdc\ 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 \npart\ and \ezdc. Then, we check if the experimental data can be better explained by a sudden or a smooth onset of the anomalous \jpsi\ suppression as a function of the number of participants.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00010537
Contributor : Sylvie Flores Connect in order to contact the contributor
Submitted on : Tuesday, December 4, 2001 - 8:45:15 AM
Last modification on : Friday, September 10, 2021 - 1:50:06 PM
Long-term archiving on: : Tuesday, June 2, 2015 - 12:12:05 PM

### Identifiers

• HAL Id : in2p3-00010537, version 1

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### Citation

M C. Abreu, B. Alessandro, C. Alexa, R. Arnaldi, M. Atayan, et al.. The dependence of the anomalous $J/\psi$ suppression on the number of participant nucleons. Physics Letters B, Elsevier, 2001, 521, pp.195-203. ⟨in2p3-00010537⟩

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