Exclusive D02KsHH HLT1 line

Edward Brendan Shields requested to merge eshields-d02kshh into master

An exclusive HLT1 line for selecting D⁰→Kₛ⁰π⁺π⁻ decays.

The line is based on the combination of two CompositeParticle objects (V) and the following requirements are made:

  1. Each of the CompositeParticle vertex χ² should be 0 < χ² < maxVChi2 (20.)
  2. The DOCA of the two vertices is DOCA(V₁V₂) < maxDOCA (3 mm)
  3. The invariant mass of the combination should be |m(V₁V₂)-m(D⁰)| < massWindow (100 MeV)
  4. The transverse momentum of the combination should be Pₜ(V₁V₂) > minComboPt_D0 (1500 MeV)
  5. The proper time of the combination should be cτ(V₁V₂) > minCTau_D0 (0.5 * 0.1229 mm)

The V with the largest z is then assumed as the Kₛ⁰ candidate and further requirements are made

  1. m(Kₛ⁰) mass window [455,545] MeV
  2. minimum Pₜ (200 MeV) of the Kₛ⁰
  3. minimum P (1500 MeV), Pₜ (200 MeV) and IP (0.2mm) among the Kₛ⁰ components
  4. the Kₛ⁰ η in [2,5]

The other V is considered as the hh and provides the D⁰ vertex, therefore

  1. minP(h₁,h₂) > 1500 MeV;
  2. 2 < η(V₁V₂) < 5;
  3. minPₜ(h₁,h₂) > 250 MeV;
  4. minIP(h₁,h₂) > 0.06 mm

The line also includes a monitoring tuple with the following information:

  • m(V₁V₂)
  • Pₜ(V₁V₂)
  • P(V₁V₂)
  • DOCA(V₁V₂)
  • cτ(V₁V₂)
  • m²(Kₛ⁰h⁺)
  • m²(Kₛ⁰h⁻)
  • minIPχ²(Kₛ⁰)
  • minIPχ²(hh)
  • minIP(Kₛ⁰)
  • minIP(hh)

Rate

Calculated with $HLTEFFICIENCYCHECKERROOT/scripts/hlt_calculate_rates.py

Line:	 Hlt1D2KshhDecision   Incl:   120.6 +/-  26.3 kHz,	Excl:    9.2 +/-  6.6 kHz

Efficiency

3.2% (1.0% exclusive) on a sample of D⁰→Kₛ⁰π⁺π⁻ decays with denominator the events where all the pions are Long reconstructable tracks with 2 < η < 5.

Talks

Edited by Maurizio Martinelli

Merge request reports