Speaker
Description
Quarkonia are produced in the initial hard scatterings and are useful probes to study the microscopic properties of the matter produced in the ultra relativistic heavy-ion collisions. The experimental results show that in nucleus-nucleus collisions, the charmonium yields are modified compared to the expectations based on the yields measured in proton proton interactions, scaled by the number of binary collisions. In proton-nucleus collisions this yield modification is due to the so-called Cold Nuclear Matter (CNM) effects such as shadowing, gluon saturation, parton energy loss, comover absorption. This information can be obtained from p-Pb collisions.
At LHC energies ($\sqrt{s_{\rm{NN}}}$ = 5.02 and 8.16 TeV), ALICE has observed a modification of the J/$\rm{\psi}$ yields in p-Pb collisions which can be understood assuming shadowing to be the dominant contribution. On the other hand, the $\rm{\psi}$(2S) was found to have a similar suppression as the J/$\rm{\psi}$ at forward rapidity, but it shows a much stronger suppression in the backward rapidity region. So, this behavior cannot be explained by the shadowing or energy loss only unlike J/$\rm{\psi}$. Final state mechanisms, as the comover absorption, should be playing a role in this region.
ALICE results on the measurement of $\rm{\psi}$(2S) yields and nuclear modification factor as a function of transverse momentum, rapidity and collision centrality in p-Pb $\sqrt{s_{\rm{NN}}}$ = 8.16 TeV collisions will be presented in the poster.
| Content type | Experiment |
|---|---|
| Collaboration | ALICE |
| Centralised submission by Collaboration | Presenter name already specified |
