Implementation of RD isolation tool

TO BE TESTED WITH Rec!3444 (merged)

This MR aims at implement a common framework to persist in the extra_output selections of particle associated to isolation, useful in several physics analysis to suppress offline the partial reconstructed background.

The goal is to have a common configurable tool to be implemented in different lines to persist a reduced amount of information, necessary to make offline studies with the isolation. This supports the idea of saving space for HLT2 BW in Turbo lines.

ATM, these are the persisted TES locations:

To get these object persisted, we can use the method select_parts_for_isolation in isolation.py as follows:

• set a list of names of particles wrt we want to calculate isolations,
• set a list of containers of particles wrt we want to calculate isolations,
• set the predicate that will filter the selection of extra particles,
• set to True the flags correspondent to the kind of isolation that we want to evaluate

The following list of extra particles are accessible to be persisted and to compute offline isolation:

• make_long_pions for long track isolation (by default: True)
• make_ttrack_pions for t-track isolation (by default: False)
• make_down_pions for downstream track isolation (by default: False)
• make_up_pions for upstream track isolation (by default: False)
• make_photons for neutral isolation (by default: True)
• make_merged_pi0s for neutral isolation with pi0s (by default: False)

Furthermore, the MR implements the method find_in_decay in isolation.py, which returns a selection of particles in the decay tree a particle container matching a given id, passed as string parameter. In this way it could be possible to save extra information only for signal children candidate and limit the space for the HLT2 BW.

Example of application could be found in b_to_xtaul_hlt2.py file.

Further developments and improvements are discussed in #494

TODO:

• Add the possibility to save merged pi0 and set by default to False
• Change ~ with not when excluding signal candidates
• Check what happen when empty array is saved in extra_outputs
• Have a rough estimation of HLT2 BW saved by implementing isolation
• Have a look at isolation variables on persisted selections on MC and data

cc: @cagapopo, @msaur, @alobosal, @htilquin, @rquaglia, @elsmith

Hlt/Hlt2Conf/python/Hlt2Conf/lines/rd/builders/rd_isolation.py

+###############################################################################
+# (c) Copyright 2023 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.                                       #
+###############################################################################
+
+#RD isolation algorithm
+from PyConf import configurable
+from PyConf.Algorithms import ThOrParticleSelection
+from Hlt2Conf.standard_particles import make_long_pions, make_up_pions, make_down_pions, make_ttrack_pions, make_photons, make_merged_pi0s
+from Hlt2Conf.isolation import extra_outputs_for_isolation
+
+from Hlt2Conf.lines.rd.builders.rdbuilder_thor import make_rd_tauons_hadronic_decay
+
+import Functors as F
+
+
+@configurable
+def find_in_decay(input=make_rd_tauons_hadronic_decay, id="pi+"):
+    """
+    Retrieve the selection of particles matching 'id' argument from 'input' decay tree
+    Args:
+        input: Composite particle
+        id: String representation of the ParticleProperty to get
+    """
+    code = (F.FILTER(F.IS_ABS_ID(id)) @ F.GET_ALL_DESCENDANTS())
+
+    return ThOrParticleSelection(
+        InputParticles=input, Functor=code).OutputSelection
+
+
+@configurable
+def select_parts_for_isolation(names=[],
+                               candidates=[],
+                               cut=(F.DR2 < 1.),
+                               LongTrackIso=True,
+                               TTrackIso=False,
+                               DownstreamTrackIso=False,
+                               UpstreamTrackIso=False,
+                               NeutralIso=True,
+                               PiZerosIso=False):
+    """
+    Add to the extra_outputs different kind of isolations by properly setting the given flag 
+    Args:
+        names: List of strings with prefix of the TES location for extra selection 
+        candidates: List of containers of reference particles to relate extra particles
+        cut: Predicate to select extra information to persist. By default: cone geometry with max dr2=1
+        LongTrackIso: Boolean flag to make isolation with long tracks. By default True.
+        TTrackIso: Boolean flag to make isolation with tt tracks. By default False.
+        DownstreamTrackIso: Boolean flag to make isolation with downstream tracks. By default False.
+        UpstreamTrackIso: Boolean flag to make isolation with upstream tracks. By default False.
+        NeutralIso: Boolean flag to make isolation with neutral particles. By default True.
+    """
+    extra_outputs = []
+
+    for name, cand in zip(names, candidates):
+        if LongTrackIso:
+            extra_outputs += extra_outputs_for_isolation(
+                name=name + "_LongTrackIsolation",
+                extra_particles=make_long_pions,
+                ref_particles=cand,
+                selection=cut)
+        if TTrackIso:
+            extra_outputs += extra_outputs_for_isolation(
+                name=name + "_TTrackIsolation",
+                extra_particles=make_ttrack_pions,
+                ref_particles=cand,
+                selection=cut)
+        if DownstreamTrackIso:
+            extra_outputs += extra_outputs_for_isolation(
+                name=name + "_DownstreamTrackIsolation",
+                extra_particles=make_down_pions,
+                ref_particles=cand,
+                selection=cut)
+        if UpstreamTrackIso:
+            extra_outputs += extra_outputs_for_isolation(
+                name=name + "_UpstreamTrackIsolation",
+                extra_particles=make_up_pions,
+                ref_particles=cand,
+                selection=cut)
+        if NeutralIso:
+            extra_outputs += extra_outputs_for_isolation(
+                name=name + "_NeutralIsolation",
+                extra_particles=make_photons,
+                ref_particles=cand,
+                selection=cut)
+        if PiZerosIso:
+            extra_outputs += extra_outputs_for_isolation(
+                name=name + "_PiZerosIsolation",
+                extra_particles=make_merged_pi0s,
+                ref_particles=cand,
+                selection=cut)
+    return extra_outputs