# FCPPL Quarkonium Production Workshop

March 30, 2017 to April 1, 2017
Peking University
Asia/Shanghai timezone

## On the Psi(2S) over J/psi production yield in pp and pA collisions

Mar 31, 2017, 10:45 AM
30m
Peking University

#### Peking University

B105, West Building of School of Physics (Next to the Metro Station "PKU East Gate", across the street from the main PKU entrance)
Talk Proton-nucleus collisions

### Speaker

Dr Gines Martinez-Garcia (Subatech CNRS)

### Description

Proton nucleus collisions are expected to be unique tool to probe the physics of the initial state of ultra relativistic heavy ion collisions, without the presence of thermalisation and collective evolution of high energy density QCD matter. However, many observations related to the production of light and strange hadrons at low transverse momentum (pT) in p-Pb collisions at the LHC surprisingly exhibit a qualitative similarity to measurements in nucleus-nucleus collisions and are in qualitative agreement with hydrodynamical model
8 calculations. Similar observations have been performed in high multiplicity proton-proton collisions at the LHC. On the other hand, the experimental results of high pT hadrons, jet, heavy quarks production in p-Pb collisions at the LHC can be explained as binary scaling with respect to pp collisions with a moderate shadowing effect as expected in the absence of collective phenomena. In the case of J/ψ and Υ(1S) production an additional energy loss mechanism has to be considered to explain their production. Among the hard probes, only the Ψ(2S), Υ(2S) and Υ(3S) exhibit a puzzling behaviour in proton-nucleus collisions at the LHC, also observed for the Ψ(2S) in central d-Au collisions at RHIC, and which violate the binary scaling. A priori, the observed relative suppression of theses quarkonium resonances in p-A collisions, ravels the interpretation of the experimental results obtained in A-A collisions.

### Primary author

Dr Gines Martinez-Garcia (Subatech CNRS)

### Presentation materials

 GinesMartinez_QuarkoniumWorkshop2017.pdf GinesMartinez_QuarkoniumWorkshop2017.pptx