Charmonium + neutral lines with vertex cuts

Lines selecting JpsiKst[KPi0] and Chic[JpsiGamma]K. Compared to previous branch (b2cc_chefdevi_neutrals-2), now has:

• vertex cuts applied;
• lower PT threshold on the pi0;
• removed overlapping JpsiK line;
• lower rates by factor of 3.5 and 1.2 for ChicK and JpsiKst.

Hlt/Hlt2Conf/python/Hlt2Conf/lines/b_to_charmonia/builders/x0_builder.py

+###############################################################################
+# (c) Copyright 2019 CERN for the benefit of the LHCb Collaboration           #
+#                                                                             #
+# This software is distributed under the terms of the GNU General Public      #
+# Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   #
+#                                                                             #
+# In applying this licence, CERN does not waive the privileges and immunities #
+# granted to it by virtue of its status as an Intergovernmental Organization  #
+# or submit itself to any jurisdiction.                                       #
+###############################################################################
+"""Definition of B2CC neutral objects: pi0, eta, eta' ...
+"""
+
+from __future__ import absolute_import, division, print_function
+from GaudiKernel.SystemOfUnits import GeV, MeV
+from Hlt2Conf.algorithms_thor import require_all, ParticleCombiner, ParticleFilter
+from Hlt2Conf.lines.b_to_charmonia.builders import basic_builder
+from Hlt2Conf.standard_particles import make_photons, make_resolved_pi0s
+import Functors as F
+from Functors.math import in_range
+
+
+def filter_pi0s(particles, pi0pt_min=1.5 * GeV):
+    code = require_all(F.PT > pi0pt_min)
+    return ParticleFilter(particles, F.FILTER(code))
+
+
+def filter_gammas(particles, gpt_min=0.5 * GeV):
+    code = require_all(F.PT > gpt_min)
+    return ParticleFilter(particles, F.FILTER(code))
+
+
+####################################
+# 1-body+GammaGamma combiners      #
+####################################
+
+
+def make_onebodygg(particles,
+                   descriptor,
+                   comb_m_min,
+                   comb_m_max,
+                   name="B2CC_OneBodyGG_Combiner",
+                   pt=2000. * MeV):
+    """
+    Combine a track and two photons
+    """
+
+    combination_code = require_all(
+        in_range(comb_m_min, F.MASS, comb_m_max), F.PT > pt)
+
+    vertex_code = require_all(F.PT > pt)
+
+    return ParticleCombiner(
+        name=name,
+        Inputs=particles,
+        DecayDescriptor=descriptor,
+        CombinationCut=combination_code,
+        CompositeCut=vertex_code)
+
+
+####################################
+# 2-body+Gamma combiners           #
+####################################
+
+
+def make_twobodyg(particles,
+                  descriptor,
+                  comb_m_min,
+                  comb_m_max,
+                  name="B2CC_TwoBodyG_Combiner",
+                  pt=1000. * MeV):
+    """
+    Combine two tracks and one photon
+    """
+
+    combination_code = require_all(
+        in_range(comb_m_min, F.MASS, comb_m_max), F.PT > pt)
+
+    vertex_code = require_all(F.PT > pt)
+
+    return ParticleCombiner(
+        name=name,
+        Inputs=particles,
+        DecayDescriptor=descriptor,
+        CombinationCut=combination_code,
+        CompositeCut=vertex_code)
+
+
+####################################
+# K*+ -> K+ Pi0(resolved) decays   #
+####################################
+
+
+def make_selected_kst2kpi0r(name="B2CC_Kst2KPi0R_Filter",
+                            descriptor='[K*(892)+ -> K+ pi0]cc',
+                            comb_m_min=792. * MeV,
+                            comb_m_max=992. * MeV,
+                            pi0pt_min=1000. * MeV,
+                            pt=1500. * MeV,
+                            pid_k=0,
+                            pt_k=500. * MeV):
+
+    kaon = basic_builder.make_kaons(pid=pid_k, pt=pt_k)
+
+    pi0 = filter_pi0s(make_resolved_pi0s(), pi0pt_min=pi0pt_min)
+
+    return make_onebodygg(
+        particles=[kaon, pi0],
+        descriptor=descriptor,
+        name=name,
+        comb_m_min=comb_m_min,
+        comb_m_max=comb_m_max,
+        pt=pt)
+
+
+####################################
+# Chi_c -> Jpsi[MuMu] Gamma decays #
+####################################
+
+
+def make_selected_chic2jpsig(name="B2CC_Chic2JpsiG_Filter",
+                             descriptor='chi_c1(1P) -> J/psi(1S) gamma',
+                             comb_m_min=3410 * MeV,
+                             comb_m_max=3610 * MeV,
+                             gpt_min=500. * MeV,
+                             pt=1000. * MeV):
+
+    jpsi = basic_builder.make_selected_jpsi2mumu()
+
+    gamma = filter_gammas(make_photons(), gpt_min=gpt_min)
+
+    return make_twobodyg(
+        particles=[jpsi, gamma],
+        descriptor=descriptor,
+        name=name,
+        comb_m_min=comb_m_min,
+        comb_m_max=comb_m_max,
+        pt=pt)