L2 multi-track SA
A new function of HLTMuon, L2 multi-tarck SA is developed to recover inefficiency against close-by muon events at L2 level. It is new L2MuonSA that can reconstruct multiple muons from a single RoI. The performance of L2 multi-track SA is discussed in ATR-22537 . I confirmed the new function works as expected; dimuon trigger efficiencies for close-by muons are improved, and there are few events that L2 multi-track SA misreconstructed more than two candidates in spite of single muon passed through in a RoI.
L2 multi-track SA can be called when muon trigger chains contains “l2mt” in these names (mt represents “m”ulti-“t”rack SA) . It does not affect the other chains, nor add any variables into existing xAOD HLTMuon objects. It creates new dedicated containers of xAOD HLTMuon objects. When no “l2mt” chain in menu, empty containers are created.
This MR includes adding a test chain “HLT_2mu10_l2mt_L1MU10” in LS2_v1.py in order to validate L2 multi-track SA . The thresholds will be adjusted later and L1_MU10 is tentatively used instead of a proper L1 item with RPC isMoreCand flag (discussed in JIRA ticket above and ATR-22243 ).