22-27 September 2016
East Lake International Conference Center
Asia/Chongqing timezone
<a href="http://hp2016.ccnu.edu.cn">http://hp2016.ccnu.edu.cn</a>

Upsilon production in Au+Au collisions at √(s_NN )= 200 GeV with the STAR experiment

25 Sep 2016, 08:50
Jing-Zhou Hall (East Lake International Conference Center)

Jing-Zhou Hall

East Lake International Conference Center

Donghu Road 142, Wuchang District, Wuhan, Hubei, China




Quark-Gluon Plasma (QGP), a new state of matter where quarks and gluons are de-confined, is believed to have existed up to a few milliseconds after the Big Bang. Quarkonia could dissociate in the QGP due to color screening of quark-antiquark potential by the surrounding partons in the medium, which was suggested as a signature of QGP formation in heavy-ion collisions. Moreover, different quarkonium states may dissociate at different temperatures depending on their binding energies. This so-called sequential melting phenomenon could be used to deduce the temperature of the QGP. However, other effects, such as regeneration from uncorrelated heavy quark-antiquark pairs, shadowing and antishadowing of nuclear structure functions, co-mover absorption, need to be taken into account when interpreting experimental results. Compared to charmonia, bottomonia is much less affected by regeneration contribution and co-mover absorption at RHIC energies, making them a cleaner probe to the QGP.

Measurements of Upsilon production have been traditionally studied via the di-electron channel at STAR. Since 2014, a new detector, the Muon Telescope Detector (MTD), has been fully installed and taking data, allowing measurements of Upsilon production via the di-muon channel. Compared to the di-electron channel, the di-muon channel has better sensitivity to different Upsilon states due to the reduced bremsstrahlung radiation. In this talk, we will present new results on Upsilon suppression in both the di-electron and di-muon decay channels in Au+Au collisions at √(s_NN )= 200 GeV based on the full data sample taken in 2014. The measured results will be compared to those at the LHC and to theoretical calculations.

Presentation type Oral

Primary author


Presentation Materials