Skip to content

B2OC: Tbc & Xibc decays with similar final states

Ivan Polyakov requested to merge Xibc-Tbc-decays into b2oc_upgrade

adding Tbc (bcu~d~ tetraquark) and Xibc decay lines to HLT2 aiming to make them similar between each other and to already existing Xibc lines. While reducing rates to bring down to <200Hz had adjusted selection for existing Xibc and Ombc lines using created make_xibc2cx, make_xibc2ccx, make_tbc2cx, make_tbc2ccx with tighter cuts

  • PT(Xibc/Tbc) > 6 GeV [was 5 GeV]
  • PIDk(K) > -2, PIDp(p) > -2 [was -5]
  • vtx(Charm)_Z - vtx(Xibc/Tbc)_Z > -0.5mm
  • in Xibc/Tbc -> Charm + hadrons: PT(p/k/pi) > 500 MeV [was mainly 250 MeV]
  • in Xibc/Tbc -> Charm1 + Charm2 + hadrons: PT(p/k) > 500 MeV, PT(pi) > 350 MeV
  • in Xibc/Tbc -> Charm + hh: sumPT(hh) > 2.25 GeV
  • in Xibc/Tbc -> Charm1 + CHarm2 + hh: sumPT(hh) > 1.25 GeV

Plus created dedicated tighter versions of D0, D+, Lc, Xic selectors named _for_xibc with

  • PIDk(K) > -2, PIDp(p) > -2 [was -5]
  • PIDk(pi) < 2 [was 5]
  • vchi2pdof < 7, [was 10]
  • tighter mass windows:
    • +-50MeV for D0->Kpi
    • +-40MeV for D+->Kpipi, D0->K3pi, Lc->pKpi, Xic+->pKpi, Xic0->ppKpi
  • and for D0->K3pi increased FD_chi2>49 [while keep 36 for all others]. Logic is that more tracks give better FD resolution, plus more pions in final state means larger background from PV.

All lines with D0 are in two variants - D0ToKPi and D0ToKPiPiPi. Merged versions D0ToKPiOrKPiPiPi are also prepared and can be included in hlt2 or sprucing at any moment.

Edited by Ivan Polyakov

Merge request reports