Abstract

ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision sNN=8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03<ycms<3.53 and −4.46<ycms<−2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at sNN=5.02 TeV and with theoretical calculations.

Highlights

  • Quarkonium resonances, i.e. bound states of a heavy quark (Q)and anti-quark (Q), are well-known probes of the formation of a quark–gluon plasma (QGP) which can occur in heavy-ions collisions

  • Anti-quark (Q), are well-known probes of the formation of a quark–gluon plasma (QGP) which can occur in heavy-ions collisions

  • All the Υ resonances show a reduction in their production yields compared to pp interactions at the same centre-of-mass energy, scaled by the number of nucleon

Read more

Summary

Introduction

Anti-quark (Q), are well-known probes of the formation of a quark–gluon plasma (QGP) which can occur in heavy-ions collisions. (nPDFs) [8,9,10,11] or through a Color Glass Condensate effective theory [12], or the coherent energy loss of the QQ pair during its path through the cold nuclear medium [13] are examples of CNM effects which can influence quarkonium production [14] The size of these effects is usually assessed in proton–nucleus collisions. These interactions allow for the investigation of additional final state mechanisms, which can modify the production in particular of the more loosely bound resonances [15,16,17]. It should be noted that all the presented results refer to the Υ inclusive production, i.e. to Υ either produced directly or coming from the feed-down of higher-mass excited states

Experimental apparatus and data sample
Data analysis
Results
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call