Heavy Flavor

Depending on the energy scale, there are two mechanisms that generate quark masses with different degrees of importance: current quark masses are generated by the electroweak symmetry breaking mechanism (Higgs mass) and spontaneous chiral symmetry breaking leads to the constituent quark masses in QCD (QCD mass). The QCD interaction strongly affects the light quarks (u, d, s) while the heavy quark masses (c, b, t) are mainly determined by the Higgs mechanism. In high-energy nuclear collisions at RHIC, heavy quarks are produced through gluon fusion and qq¯ annihilation. Heavy quark production is also sensitive to the parton distribution function. Unlike the light quarks, heavy quark masses are not modified by the surrounding QCD medium (or the excitations of the QCD medium) and the value of their masses is much higher than the initial excitation of the system. It is these differences between light and heavy quarks in a medium that make heavy quarks an ideal probe to study the properties of the hot and dense medium created in high-energy nuclear collisions.

 

Heavy flavor analyses at STAR can be separated into quarkonia, open heavy flavor and heavy flavor leptons.


 

Upsilon Analysis in d+Au 2008

Upsilon yield and nuclear modification factor in d+Au collisions at sqrt(s)=200 GeV.

PAs: Anthony Kesich, and Manuel Calderon de la Barca Sanchez.

 

Upsilon Analysis in p+p 2009

Upsilon cross-section in p+p collisions at sqrt(sNN) = 200 GeV, 2009 data.

Update on J/psi polarization study

Speaker : Barbara Trzeciak ( WUT )


Talk time : 14:00, Duration : 00:45

Response to PRD referee comments on Upsilon Paper

First Round of Referee Responses

Click here for second round.

e-h correlation in Run9 500 GeV

Speaker : Wei Li ( SINAP/UCLA )


Talk time : 16:15, Duration : 00:30

Embedding Discussion

NPE analysis in run 2008 d+Au

Speaker : Wenqin Xu ( UCLA )


Talk time : 16:15, Duration : 00:30

Varying the Continuum Contribution to the Dielectron Mass Spectrum

Initial Normalization

Estimating Drell-Yan contribution from NLO calculation.

Ramona calculated the cross section for DY at NLO and sent the data points to us.  These were first shown in the RHIC II Science Workshop, April 2005, in her Quarkonium

Code to run Pythia and produce b-bbar -> e+ e- events

// main00.cc
// Modified from the main01.cc
// which is a part of the PYTHIA event generator.
// Copyright (C) 2008 Torbjorn Sjostrand.

Using Pythia 8 to get b-bbar -> e+e-

We used Pythia 8 to produce b-bbar events. First we used the default Pythia 8.

Upsilon Analysis

Links related to Upsilon Analysis.

Summary

Speaker : Manuel Calderon


Talk time : 17:00, Duration : 00:20

Hard Probes 2008 Discussion

Speaker : All


Talk time : 16:15, Duration : 00:45

J/psi in 200 GeV Cu+Cu

Speaker : Daniel Kikola


Talk time : 15:30, Duration : 00:45

Upsilons in Run7 200 GeV Au+Au

Speaker : Debasish Das


Talk time : 14:45, Duration : 00:45

2007 AuAu Upsilon background and Preshower

LInk to my webpage about Upsilon and Preshower can be found here

www4.rcf.bnl.gov/~rfc/

Email:

Speaker : Rory Clark


Talk time : 14:00, Duration : 00:45

Lunch

e-h Correlations in CuCu 200GeV

Speaker : Jaroslav Bielcik


Talk time : 11:15, Duration : 00:45

Discussion on long paper on e-h, e-D, D* in jets