Bottomonium measurements in pp, pPb and PbPb using the CMS detector

Hot Quarks 2014: Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions

Filipovic, Nicolas^1

Laboratoire Leprince-Ringuet, École Polytechnique, Palaiseau cedex

91128, France^1

关键词: Bottomonium;    CMS detectors;    Compact Muon solenoids;    Experimental apparatus;    Pb-Pb collisions;    Quark-gluon plasma;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/612/1/012021/pdf
DOI  :  10.1088/1742-6596/612/1/012021

来源: IOP

【 摘 要 】

Bottomonia are important probes of the quark-gluon plasma since they are produced at early times and propagate through the medium, mapping its evolution. The three Υ states (1S, 2S, 3S) were measured separately using the Compact Muon Solenoid (CMS) experimental apparatus and observed to disappear sequentially in PbPb collisions at 2.76 TeV. However, recent measurements in pp and pPb collisions, at 2.76 and 5.02 TeV respectively, show a surprising dependence of the excited state (2S or 3S) over the ground (1S) state ratio, as a function of event activity. The three Υ states are also observed to be individually more produced in events with more activity. We review the latest results from pp, pPb and PbPb collisions and highlight their possible interpretations.