Heavy Flavour Production at HERA-B

1. J/ e+ preliminary 2002/2003 data (di-muon sample) p e- -0.35 < xF< 0.1 0 < pT < 6 GeV pA bb X bJ/ψ Y e+e-/+- Y (×10-4) E789 (Au) (×10-3) background: mixed events (×10-2) E771 (p-Si) NRQCD after background subtraction (×10-1) HERA-B (W) W Au Be C Si Ti CEM fit results at s = 41.6 GeV: [GeV-2] <pT>[GeV/c] E369/ 610/ 673 (p-Be) entries/(10 MeV/c2) (×10) E771 (Si) HERA-B (Ti) π-A HERA-B (C) E672/E706 (Be) CDF (p-p) ISR (p-p) 2000 A expected final precision 2002/3 prelim. pT[GeV] E705 (p-Li) m(μ+μ-γ)-m(μ+μ-) [GeV/c2] HERA-B Heavy Flavour Production at HERA-B Presented by Andrey Bogatyrev (bogatyr@mail.desy.de) for the HERA-B collaboraton Introduction Hera-B was a fixed target spectrometer operating at the HERA proton beam at DESY (Hamburg). The main fields of interest of the experiment are the study of charm and beauty production in pA interactions at √s = 41.6 GeV. During the data taking period 2002/3, huge samples of high quality data were recorded with different target nuclei (C, Ti, W). The Hera-B detector 2002/3 data taking: • High rate forward spectrometer (10 MHz interaction rate) • Angular coverage: 15 - 220 mrad in bending plane, • 15 - 160 mrad in vertical plane • Designed for high interaction rates • Particle identification (e, m, p, K, p) • Hardware track-trigger for lepton pairs (ee, mm) • Multiple trigger levels: electron and muon pretriggers, hardware first level trigger, software second level trigger. • On-line event reconstruction with PC-farm • Interaction of 920 GeV/c protons with nuclei of target wires (C, Ti, W) • Running time ~480 h • Minimum bias events ~210 Mio • Dilepton trigger evens ~150 Mio • “Glueball” trigger events ~60 Mio • Hard photon trigger events ~10 Mio • Peak DAQ rate (MinBias) ~1kHz • J/ rate (events/time) ~1000/hour Open charm in minimum bias data J/ cross section in minimum bias data J/  + - 100  12 J/  e+ e- 57  13 PHYS. LETT. B 638, 407 (2006) Test of universality of non-perturbative matrix elements of quarkonia • Fit the existing experimental data using function based on NRQCD calculations at NLO • Scale parameter: 0 = 2mc with mc = 1.5 GeV 0 = F(factorization)= R(renormalization) • PDF sets: MRST2002nlo and CTEQ6m • Color-singlet matrix elements from potential model calculations • Color-octet matrix elements extracted from CDF data • Introduce free scaling parameters for S-wave matrix elements J/ and (2S) = fraction of color-octet contribution required relative to CDF results F. Maltoni et al. PHYS. LETT. B 638, 202 (2006) Conclusions 0.01 < J/ < 0.31 and 0.02 < (2S) < 0.14 Required color-octet contribution about 10% of that for Tevatron data. Supports HERA ep data which do not need large octet contributions. c J/  production J/ production in pA collisions Mass difference M=M(l+ l- ) - M(l+ l- ) Reconstructed mass spectra <pT> grows logarithmically with A: <pT> grows with s: <pT>  0.8 + 0.01·s A-dependence Differential distributions in xF and pT  = 0.969 ± 0.003stat± 0.021sys Cronin effect R(c)  production (2S) production Open beauty production (2S) / J/ ratio Mass spectra after detachment cuts Fit: A· ((1S) + (2S) + (3S)) + B· Drell-Yan + combinatorial (1S):(2S):(3S) fixed to E605 From MC From like-sign pairs improvement of B‘(): R = 0.032  0.005stat  0.004sys better than current PDG value PHYS. LETT. B 638 (2006) Submitted to EPJC PHYS. REV. D 73, 052005 (2006)