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.

• Dataset QA
  • Trigger ID, runs
    
    • Trigger ID = 210601
      • ZDC East signal + BEMC HT at 18 (Et>4.3 GeV) + L2 Upsilon
      • Total Sampled Luminosity: 32.66 nb^-1; 1.216 Mevents
        • http://www.star.bnl.gov/protected/common/common2008/trigger2008/lum_pertriggerid_dau2008.txt
    •  
  • Run by Run QA
  • Integrated Luminosity estimate
  • Systematic Uncertainty
• Acceptance (Check with Kurt Hill)
  • Raw pT, y distribution of Upsilon
  • Accepted pT, y distribution of Upsilons
  • Acceptance
  • Raw pT, eta distribution of e+,e- daughters
  • Accepted pT, eta distribution of e+,e- daughters
  • Comparison plots between single-electron embedding, Upsilon embedding
• L0 Trigger
  • DSM-ADC Distribution (data, i.e. mainly background)
  • DSM-ADC Distribution (Embedding) For accepted Upsilons, before and after L0 trigger selection
  • Systematic Uncertainty (Estimate of possible calibration and resolution systematic offsets).
  • "highest electron/positron Et" distribution from embedding (Accepted Upsilons, before and after L0 trigger selection)
• L2 Trigger
  • E1 Cluster Et distribution (data, i.e. mainly background)
  • E1 Cluster Et distribution (embedding, L0 triggered, before and after all L2 trigger cuts)
  • L2 pair opening angle (cos theta) data (i.e.  mainly background)
  • L2 pair opening angle (cos theta) embedding. Needs map of (phi,eta)_MC to (phi,eta)_L2 from single electron embedding. Then a map from r1=(phi,eta, R_emc) to r1=(x,y,z) so that one can do cos(theta^L2) = r1.dot(r2)/(r1.mag()*r2.mag()). Plot cos theta distribution for L0 triggered events, before and after all L2 trigger cuts. (Kurt)
  • L2 pair invariant mass from data (i.e. mainly background)
  • L2 pair invariant mass from embedding. Needs simulation as for cos(theta), so that one can do m^2 = 2 * E1 * E2 * (1 - cos(theta)) where E1 and E2 are the L2 cluster energies. Plot the invariant mass distribution fro L0 triggered events, before and after all L2 trigger cuts. (Check with Kurt)
• PID
  • dE/dx
    • dE/dx vs p for the Upsilon triggered data
    • nsigma_dE/dx calibration of means and sigmas (done by C. Powell for his J/Psi work)
    • Cut optimization (Maximization of electron effective signal)
    • Final cuts for use in data analysis
  • E/p
    • E/p distributions for various p bins
    • Study of E calibration and resolution between data and embedding (for L0 Trigger systematic uncertainty)
    • Resolution and comparison with embedding (for cut efficiency estimation)
• Yield extraction
  • Invariant mass distributions
    • Unlike-sign and Like-sign inv. mass
    • Like-sign subtracted inv. mass
    • Crystal-Ball shapes from embedding/simulation. Crystal-ball parameters to be used in fit
  • Fit to Like-sign subtracted inv. mass, using CB, DY, b-bbar
    • Contour plot (1sigma and 2sigma) of b-bbar cross section vs. DY cross section
    • Upsilon yield estimation and stat. + fit error
• Cross section calculation.
  • Yield, dN/dy
  • Integrated luminosity (for 1/N_events, where N_events were the total events sampled by the L0 trigger)
  • Efficiency (Numbers for each state, and cross-section-branching-ratio-weighted average)
  • Uncertainty
  • pt Distribution (invariant, i.e. 1/N_event 1/2pi, 1/pt dN/dpt dy) in |y|<0.5 vs pt) This might need one to do the CB, DY, bbbar fit in pt bins.
• Nuclear Modification Factor
  • Estimation of <Npart> for the dataset, and uncertainty.
  • Putting it all together: dN/dy in dAu, Npart, Luminosity (N_events), divided by the pp numbers (dsigma/dy, sigma_pp)
  • Plot of R_dAu vs y, comparison with theory
  • Plot of R_dAu vs Npart, together with Au+Au
  • Plot of R_dAu vs pt.  Try to do together with Au+Au (minbias, maybe in centrality bins, but maybe not enough stats)