Skip to content

Modify the etac mass window in StrippingBandQ/StrippingLb2EtacKp.py

Mengzhen Wang requested to merge mengzhen-Lb2etacpK_etacMassWindow into 2018-patches

We would like to modify the mass window cut of etac in the stripping lines of StrippingLb2EtacKp.py for the 2018 restripping.

The current mass window of etac is (2.8, 3.2)GeV, and will lead to a tight restriction when determining the fit region of m(etac) with a Lambda_b0 mass constrain. We propose to change the mass window to (2.7, 3.3) GeV.

The rate and CPU time have been tested using 50,000 test events. The result is:

  1. The existing stripping line, with m(etac) in (2.8, 3.2)GeV:
StrippingReport                                                INFO Event 50000, Good event 50000
 |                                              *Decision name*|*Rate,%*|*Accepted*| *Mult*|*ms/evt*|
 |_StrippingGlobal_                                            |  0.1860|        93|       |  10.143|
 |_StrippingSequenceStreamBhadron_                             |  0.1860|        93|       |  10.133|
 |!StrippingLb2EtacKp_KsKPiLine                                |  0.0340|        17|  2.059|   8.362|
 |!StrippingLb2EtacKp_PPbarLine                                |  0.0040|         2|  1.500|   0.047|
 |!StrippingLb2EtacKp_4hLine                                   |  0.1620|        81|  4.790|   0.372|
 |!StrippingLb2EtacKp_KsKPiLine_TIMING                         |  0.0340|        17|  2.059|   0.037|
 |!StrippingLb2EtacKp_PPbarLine_TIMING                         |  0.0040|         2|  1.500|   0.026|
 |!StrippingLb2EtacKp_4hLine_TIMING                            |  0.1620|        81|  4.790|   0.051|

(Full log file in lxplus: /afs/cern.ch/user/m/mengzhen/public/StrippingTest/Lb2etacpK_old.log)

  1. If change m(etac) cut to be within (2.7, 3.3)GeV:
StrippingReport                                                INFO Event 50000, Good event 50000
 |                                              *Decision name*|*Rate,%*|*Accepted*| *Mult*|*ms/evt*|
 |_StrippingGlobal_                                            |  0.2360|       118|       |  12.036|
 |_StrippingSequenceStreamBhadron_                             |  0.2360|       118|       |  12.023|
 |!StrippingLb2EtacKp_KsKPiLine                                |  0.0480|        24|  2.333|   9.783|
 |!StrippingLb2EtacKp_PPbarLine                                |  0.0100|         5|  1.200|   0.063|
 |!StrippingLb2EtacKp_4hLine                                   |  0.2020|       101|  5.683|   0.489|
 |!StrippingLb2EtacKp_KsKPiLine_TIMING                         |  0.0480|        24|  2.333|   0.043|
 |!StrippingLb2EtacKp_PPbarLine_TIMING                         |  0.0100|         5|  1.200|   0.037|
 |!StrippingLb2EtacKp_4hLine_TIMING                            |  0.2020|       101|  5.683|   0.064|

(Full log file in lxplus: /afs/cern.ch/user/m/mengzhen/public/StrippingTest/Lb2etacpK_new.log)

The increase of rate and CPU time/event is around 25% and 20%, respectively.

Edited by Mengzhen Wang

Merge request reports