Quarikonia Study

1. Motivation of Quarkonia (qqbar -> +mu -mu, J/psi, Upsilon family) Study at CMS (Fig. 1)

- Quarkonia's step-wise suppression at high pt region is the one of most direct probes of QGP (Quark-gluon-plasma)

- J/Psi's suppression is already observed in SPS and RHIC.

- So, how about it in CMS ? (there could be more huge suppression or enhanced regeneration ?) and how about Upsilon ?

What is more benefits of CMS than other experiments ?

- It can make plasma hotter, longer-lived than RHIC (it can be easy to dissolute the particles which has large binding energy)

- provide good circumstances to produce Quarkonia highly

- high luminosities : 5*10^26 cm^-2 s^-1 (increase events rate)

- high gluon density at low-x, (the almost particles of heavy-flavor quarks is made by gluon-gluon fusion)

- New possibility of Upsilon family (Y, Y', Y'')

2. Quarkonia Generation with CMSSW

Introduction to CMSSW (making full events of quarkonia generation)

quarkonia generation with CMSSW at CMSSW_1_6_0

- used 'CSA07Charmonium_Pt_20_inf_GEN_SIM.cfg' and generated 500 events (for J/Psi)

3. Analysis of Quarkonia

- using module "PhysicsTools/CandExamples"

Analysis of J/Psi generation

- Invariant Mass of J/Psi

- Eta distribution of J/Psi

- Phi distribution of J/Psi

- Pt distribution of J/Psi

Analysis of Upsilon generation

- Invariant Mass of Upsilon

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- Eta distribution of Upsilon

- Phi distribution of Upsilon

- Pt distribution of Upsilon

-- DongHoMoon - 26 Oct 2007