120 likes | 270 Views
Muon simulation for p+A system Preliminary studies with HSD. Partha Pratim Bhaduri Subhasis Chattopadhyay VECC, Kolkata. Motivation.
E N D
Muon simulation for p+A systemPreliminary studies with HSD ParthaPratimBhaduri SubhasisChattopadhyay VECC, Kolkata
Motivation • The aim of the relativistic heavy-ion collisions is to study the onset of de-confinement and the properties of the de-confined media in the laboratory. Hence it is necessary to define unambiguous and experimentally viable probes for de-confinement. • In this respect proton-nucleus (p+A) collisions must be a fundamental component of any heavy-ion physics program • Defines the reference baseline relative to which we recognize HI specific phenomena • p+A collisions provide a measure of the nuclear effects – helps in disentangling the “QGP” effect from the “non-QGP” effects. Here there is no formation time for the “secondary” medium , hence such collisions provide as essential tool to correctly account for the effect of the nuclear medium initially present.
System • The specifications of the system chosen are: • Target : Au , Cu, S, O, C • Projectile : p (1, 1) • Beam energy : 30 GeV • Event generator used : HSD – 2.5 • Events : 5,000 (ISUBS = 50, NUM = 100)
Results with HSD J/Psi pseudo-rapidity distribution pC pO pS pCu pAu pC pO pS pCu pAu CMS Frame Laboratory Frame
J/Psi transverse momentum spectra pC pO pS pCu pAu
Laboratory Frame CMS Frame Muons decayed from J/Psi Isotropic decay in J/Psi rest frame Laboratory Frame
Simulation • CbmRoot Version: Trunk version • Number of events : 4000 • Much geometry : Standard Geometry • 2 layers in 5 stations • Distance between layers 10 cm. • Gap between absorbers 20 cm • 3 layers at the last trigger station • Total 13 layers • Total length of Much 350 cm • Signal : J/y decayed muons from HSD for p+Au system for 30 GeV p beam • Background : central UrQMD events for p+ Au at 30 GeV/n • Much Hit producer w/o cluster & avalanche • L1(STS) & Lit (Much) tracking with branching Absorber thickness (cm): 20 20 20 30 35 100
Analysis • Use the reconstructed data after the full tracking through the detector set-up. • Reconstructed global tracks have to satisfy : • Fraction of true hits (truehits/(true hits+ wrong hits+fake hits) >= 0.7 • No. of STS Hits associated with the global track >=4 • No. of Much Hits associated with the global track >=10 • Chi2 primary <=2 3rd CBM-India Collaboration Meet
Detector Acceptance Raw HSD Layer # 1 Layer # 3 Layer # 5 Layer # 7 Layer # 9 Layer # 11
Invariant mass spectra Pure HSD Reconstruction efficiency : 25 % Embedded Reconstruction efficiency : 23.8 % Negligible background effect
Thank You 3rd CBM-India Collaboration Meet