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Tune BdsToKsKs lines

Christina Agapopoulourequested to merge
ca_bds2ksks_tune2025 into bnoc_run3

This MR attempts to lower the BW of BdsToKSKS lines.

It was noticed that a loose max ipchi2 cut on the B candidate has less than 5% reduction of 2024 MC reprocessed* signal, while it reduces the rate by 50% on 2025 data that were produced here

*2024 data and HLT2 MC was heavily affected by the decay time bug for these lines. To study the 2024 MC I reran the full hlt1 & hlt2 chain from 2025-patches .

It would be good to verify the rates/efficiencies on 2025 MC. But the ipchi2_max cut seems harmless on the studies done so far.

The reduction in bandwidth also allows us to extend the upper limit of the Bds mass from 5700 MeV to 6000 MeV. It may potentially help us stabilize the background in Run 3 analysis fits.

TODO:

  • Run MR on the bnoc snippet and put results here
  • Verify rates/efficiencies with 2025 MC. Verified with 2024 MC on 2025 stack.

Summary of changes:

  • Add a cut on Bds Own PV IP chi^2 < 50
  • Extend the Bds mass limit from 5700 MeV to 6000 MeV

The combined effect of the changes is a reduction of 43% in bandwidth

=== Before the proposed update ===
LAZY_AND: Hlt2BnoC_BdsToKSKS_DDDD    #=100002  Sum=3   Eff=|(0.002999940 +- 0.00173199)%|
LAZY_AND: Hlt2BnoC_BdsToKSKS_LLDD    #=100002  Sum=13  Eff=|(0.01299974 +- 0.00360524)%|
LAZY_AND: Hlt2BnoC_BdsToKSKS_LLLL    #=100002  Sum=2   Eff=|(0.001999960 +- 0.00141417)%|
Bandwidth: 26.1015 MB/s

=== After the proposed update ===
LAZY_AND: Hlt2BnoC_BdsToKSKS_DDDD    #=100002  Sum=4   Eff=|(0.003999920 +- 0.00199992)%|
LAZY_AND: Hlt2BnoC_BdsToKSKS_LLDD    #=100002  Sum=8   Eff=|(0.007999840 +- 0.00282826)%|
LAZY_AND: Hlt2BnoC_BdsToKSKS_LLLL    #=100002  Sum=2   Eff=|(0.001999960 +- 0.00141417)%|
Bandwidth: 14.8057 MB/s

@yamhis

Edited by Kerim Guseinov

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