Clean up T-track combiners and define standard builders

The aim of this MR is to clean up some of the existing T-track builders, and define standard builders to use across WGs.

Currently, the T-track combiners are defined in bandq, but these are being used across multiple WGs, with some MRs duplicating the code.

Given the complexities of selections with T tracks (extrapolation, large combinatorics, decreased resolution, etc), it makes sense to minimise the number of builders where possible.

There are currently two reconstruction sequences, depending on whether or not the T track combination can be "gated" by a rare process. If it can't, a two step MVA filtering is applied to the tracks before running the full reco sequence to improve throughput.

This would imply four builders:

• MVA filtered (should be default)
  • \Lambda
  • K_S^0
• Unfiltered (for "gated" control flows only)
  • \Lambda
  • K_S^0

To-do:

• Decide best location (decided to be standard_particles)
• Copy to standard_particles
• Clean up existing code

Hlt/Hlt2Conf/python/Hlt2Conf/lines/bandq/builders/b_to_jpsiX_TT_lines.py

@@ -14,7 +14,7 @@ Define a set of B -> dimuon X combinations, where X is reconstructed using T-tra
 from Hlt2Conf.algorithms_thor import ParticleCombiner
 from Functors.math import in_range
 from Hlt2Conf.lines.charmonium_to_dimuon_detached import make_detached_jpsi
-from .V0_to_TT_builders import make_LambdaRKTT, make_KsRKTT, make_ttrack_pions_for_V0, make_ttrack_protons_for_V0
+from Hlt2Conf.standard_particles import make_LambdaTT_gated, make_KsTT_gated
 from RecoConf.reconstruction_objects import make_pvs
 from GaudiKernel.SystemOfUnits import GeV, MeV
 import Functors as F
@@ -23,7 +23,7 @@ from PyConf import configurable
 
 @configurable
 def make_Lb2JpsiLambdaTT(make_jpsi=make_detached_jpsi,
-                         make_lambda=make_LambdaRKTT,
+                         make_lambda=make_LambdaTT_gated,
                          make_pvs=make_pvs,
                          mass_combination_min=3 * GeV,
                          mass_combination_max=10 * GeV,
@@ -44,10 +44,7 @@ def make_Lb2JpsiLambdaTT(make_jpsi=make_detached_jpsi,
 
     pvs = make_pvs()
     Jpsi = make_jpsi()
-    lambdas = make_lambda(
-        pions=make_ttrack_pions_for_V0(),
-        protons=make_ttrack_protons_for_V0(),
-        pvs=pvs)  # to do -- is this best style?
+    lambdas = make_lambda()
 
     combination_cuts = F.require_all(
         in_range(mass_combination_min, F.MASS, mass_combination_max),
@@ -76,7 +73,7 @@ def make_Lb2JpsiLambdaTT(make_jpsi=make_detached_jpsi,
 
 @configurable
 def make_Bd2JpsiKsTT(make_jpsi=make_detached_jpsi,
-                     make_ks=make_KsRKTT,
+                     make_ks=make_KsTT_gated,
                      make_pvs=make_pvs,
                      mass_combination_min=2.6 * GeV,
                      mass_combination_max=9.6 * GeV,
@@ -97,9 +94,7 @@ def make_Bd2JpsiKsTT(make_jpsi=make_detached_jpsi,
 
     pvs = make_pvs()
     Jpsi = make_jpsi()
-    ks = make_ks(
-        pions=make_ttrack_pions_for_V0(),
-        pvs=pvs)  # to do -- is this best style?
+    ks = make_ks()
 
     combination_cuts = F.require_all(
         in_range(mass_combination_min, F.MASS, mass_combination_max),