RJPsi analysis - Pisa

This page presents general information pertinent to the Pisa group regarding the R(J/psi) analysis in the leptonic channel performed by ETH and Pisa groups.

Organization and activity

The people involved in the analysis are: Shubhi Parolia, Alberto Messineo, Franco Ligabue, Fabrizio Palla, Gabriel Ramirez.

• The weekly working meeting is held every Friday at 9:30hrs (GMT+1), hosted in the indico category https://agenda.infn.it/category/455/
• ETH + Pisa weekly report meeting is held every Friday at 16:00hrs (GMT+1), hosted in the indico category https://indico.cern.ch/category/7491/
• Biweekly Hadronic meeting is held on Monday at 11:00hrs (GMT+1), hosted in the indico category https://indico.cern.ch/category/7491/

Other related meetings:

• VFS (Violation of Fundamental Symmetries) - Wednesday 13:00hrs (GMT+1) - hosted in the indico category https://indico.cern.ch/category/10949/

Topic related presentations:

• Federica Riti (ETH) - R(J/psi) analysis status. Leptonic channel - 4.May.2021 - here
• Federica Riti (ETH) - R(J/psi) analysis. Leptonic channel - BPH Jamboree - 15.12.2020 - here
• Gino Isidori - Theoretical form factor uncertainty - 6.7.2020 - https://indico.cern.ch/event/935680/
• Pisa group - Q^2 resolution studies - 6.7.2020 - here
• Gino Isidori - Notes on LFU tests in Bc -> J/psi l nu decays - 22.6.2020 - here
• Pisa group - R(J/Psi) studies at Pisa - R(J/psi) WG meeting - 9.6.2020 - here
• Pisa group - Muon Identification studies - 27.7.2020 - here

MC generation status

Jira ticket to increase 2018 sample priority https://its.cern.ch/jira/browse/HIGHPRIOREQ-209

• inclusive Bc (this consists of three separate batches because of purely technical reasons)

https://dmytro.web.cern.ch/dmytro/cmsprodmon/workflows.php?prep_id=task_BPH-RunIISummer20UL18pLHEGEN-00080

https://dmytro.web.cern.ch/dmytro/cmsprodmon/workflows.php?prep_id=task_BPH-RunIISummer20UL18pLHEGEN-00081

https://dmytro.web.cern.ch/dmytro/cmsprodmon/workflows.php?prep_id=task_BPH-RunIISummer20UL18pLHEGEN-00082

• inclusive Jpsi(mm) + X

https://dmytro.web.cern.ch/dmytro/cmsprodmon/workflows.php?prep_id=task_BPH-RunIISummer20UL18GEN-00016

• Jpsi(mm) + mu

https://dmytro.web.cern.ch/dmytro/cmsprodmon/workflows.php?prep_id=task_BPH-RunIISummer20UL18GEN-00017

Tasks:

GDoc of ongoing task for the Pisa group:

https://docs.google.com/document/d/13agcEwFtP2z7gg2I0pDFbdLflo89cY4hqa6G1HCuAS8/edit?usp=sharing

Task	Group	Priority	Status	Details
Preselection cuts optimisation	Pisa	High	Ongoing	Shubhi is studing the implementation of a genetic algorithm to perform the optimisation
Event selection using NN (2 vs 3 classes)	Both	Medium	Pending
Regression I	Pisa	High	Ongoing	Plug into the new reconstruction
Regression II	Pisa	High	Ongoing	Check effect on backgrounds / discrimination (simple plots / roc curves?)
Background Studies: combinatorial background 1	Pisa	High	Pending	Produce the distribution of the uncorrelated muon forming a Jpsi using SB distributions and comparison between them
Background Studies: combinatorial background 2	ETH	High	Pending	Jpsi(mm) + mu -> from MC, use EvtGen to force decays; 3 mu → hard? Event mixing? But small?
Background Studies: fakes	Pisa	High	Pending	Check pi/K fake rates, Use Bc -> Jpsi pi to get a pure sample of pions in data, B+ -> jpsi K+ to get a pure sample kaons in data (maybe something different now?)
Muon id studies (soft, medium...)	Pisa	Medium	Done	To be redone to include: New reconstruction, full source of simulated background available and produce improved plots
Muon id efficiency computation	Pisa	Medium	Pending?
Studies on the vertex probability and 3D impact parameter	Pisa	Medium	Ongoing	Fabrizio worked on this and point out the utility of these variable for discrimination between the different contributions. Complement with samples reconstructed with the new code.
Definition of control regions	ETH	Medium		Possibly derive corrections
Form factor MC reweighing	ETH	Medium	Ongoing	Detailed info. Needs miniAOD inputs. May end up being an additional producer in the nanoAOD sequence. Riccardo working on the implementation at the moment
MC corrections		Low	Pending	ID & trigger: see if these SF can be recycled from BPH / MUON POG
Fit model: how to input mu and tau (free / prior?)	ETH	Medium	Done	assume PDG Jpsipi /Jspimunu BR and fit Jpsipi, taunu is free
Fit model: signal subtraction in sideband region	ETH	Medium	Done
Fit model: design a blinding strategy	ETH	Medium	Done	obfuscate tau normalisation using random number
Fit model: control region	ETH	Medium		tau-free, muon enriched to measure the muon BR
BParking		Low
Other B hadron decays into Jpsi + mu I	ETH	Medium	Ongoing	New samples in the making
Other B hadron decays into Jpsi + mu II	ETH	Medium	Done	Check if Jpsi mm gamma is included in the sample. Yes, in the new MC
Other B hadron decays into Jpsi + mu III	ETH	Medium	Done	Check Bc decays in this MC (and remove if signal!) -> producing dedicated Bc MCs
Decide what reconstruction code to use	Both	Ultrahigh	Done	We decided to develop a version in between the two codes parting from ETH version
Decide on the PV to choose from the collection	Pisa	High	Done
Moved to CMSSW_10_6_X for UL	Both	Low	Done
Use 2016, 2017 and 2018 data?	Both	Low	Pending	Start from 2018 and then trickle down? -- 2018 > 2017 > 2016, 16 only if really needed

Details of the analysis

MC productions details

Explanaition of how the samples were produced and how to use them from Riccardo https://indico.cern.ch/event/1018391/contributions/4273741/attachments/2212859/3745528/rjpsi_22_3_2021.pdf

Latest ntuples

Sample	Weighting factors 21May7
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/data_ptmax_merged.root	N.A.
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar18/datalowmass_ptmax_merged.root	N.A.
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_chic0_mu_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_chic1_mu_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_chic2_mu_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_hc_mu_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_jpsi_3pi_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_jpsi_hc_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_jpsi_mu_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_jpsi_pi_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_jpsi_tau_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_psi2s_mu_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/BcToJPsiMuMu_is_psi2s_tau_merged.root	0.52
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar15/HbToJPsiMuMu_ptmax_merged.root	6.7 (jpsi_x)
root://cms-xrd-global.cern.ch//store/user/friti/dataframes_2021Mar16/HbToJPsiMuMu3MuFilter_ptmax_merged.root	8.5 (jpsi_x_mu)

(Work in progress)

Selection of PV... Differences between UL and legacy...

Establish three categories for the study:

• JPsi + Tk trigger.
• Dimuon0 + muon trigger.
• Both together.

General details:

Analysis workflow diagram can be found here. (Work in progress)

Trigger path used:

• HLT_DoubleMu4_JpsiTrk_Displaced_v* : pT(µ)>4 GeV; pT(Jpsi)>6.9 GeV; 2.9 < m(µ+µ-) < 3.3 GeV, a vertex CL >10% and Lxy/sigma(Lxy)>3 pT(tk)> 1.2 GeV and chi^2 (µ+µ-tk) vertex/ndof <10. Where µ stands for the muons coming from the Jpsi.
• HLT_Dimuon0_Jpsi3p5_Muon2_v*: Requires three muons. pT(µ)>2 GeV; pT(muons forming the Jpsi)>3.5 GeV; m(µ+µ-) between 2.9 and 3.3 GeV, and a vertex CL>0.5%. The HLT requires three muons in the CMS geometrical acceptance: two of these muons need to be oppositely charged and form a J/Psi candidate with pT > 3.5 GeV, invariant mass in the range 2.95 - 3.25 GeV and vertex probability larger than 0.5%; the third muon is required to have pT > 2.0 GeV.

Offline cuts: pT(mu) > 4 GeV; 2.95 < mass(J/Psi) < 3.25 GeV; Soft muons; pT(J/Psi) > 8 GeV

Muon IDs definitions: https://twiki.cern.ch/twiki/bin/view/CMS/SWGuideMuonIdRun2

Code & samples

Running currently on UL samples.

• Reconstruction here
• Addition of puWeights here
• Nano skimmer here

MC samples global tag: 106X_upgrade2018_realistic_v11_L1v1

Process	DAS name	DBS instance	nevents	gen. cuts & filtering	comments
BcToJpsiTauNu*	/BcToJPsiTauNu_TuneCP5_13TeV-bcvegpy2-pythia8-evtgen/RunIISummer19UL18MiniAOD-106X_upgrade2018_realistic_v11_L1v1_ext1-v2/MINIAODSIM	prod/global	6187083
BcToJpsiMuNu*	/BcToJPsiMuNu_TuneCP5_13TeV-bcvegpy2-pythia8-evtgen/RunIISummer19UL18MiniAOD-106X_upgrade2018_realistic_v11_L1v1_ext1-v2/MINIAODSIM	prod/global	7475467
OniaX*	/OniaAndX_ToMuMu_MuFilter_SoftQCDnonD_TuneCP5_13TeV-pythia8-evtgen/RunIIAutumn18MiniAOD-102X_upgrade2018_realistic_v15-v1/MINIAODSIM	prod/global	93757093
Bc mix	private prod /store/user/manzoni/RJPsi Bc PMX HLT RECO MINI 28oct20 v5

*Samples currently used and will be replaced soon with the central production coming up.

Data samples gloabl tag: 106X_dataRun2_v28 lumimask here

Sample	DAS name	nevents	comments
Charmonium-Run2018A	/Charmonium/Run2018A-12Nov2019_UL2018_rsb-v1/MINIAOD	93082605
Charmonium-Run2018B	/Charmonium/Run2018B-12Nov2019_UL2018-v1/MINIAOD	46847388
Charmonium-Run2018C	/Charmonium/Run2018C-12Nov2019_UL2018-v1/MINIAOD	35346793
Charmonium-Run2018D	/Charmonium/Run2018D-12Nov2019_UL2018-v1/MINIAOD	217135606

Useful information

• R(J/psi) measurement - LHCb paper - arXiv , PRL 120, 121801 (2018). Measurement 2 std from SM.
• Directory to share plots or other items common to the analysis: https://cernbox.cern.ch/index.php/s/aqqW54cYEoiQW9Y
• Document with the efficiencies of the HLTs: https://docs.google.com/document/d/1Wmz2nawSKo5o-FeH_JeK8Oe1Si3kDRZ1BaMSMvtyNY8/edit?usp=sharing
• RJPsi general document: https://docs.google.com/document/d/1r9TpwK-Tfa7D_w0sQdk53Eb1CquqZDpl4o8bgR-RO7I/edit?usp=sharing
• Hammer reweighting: https://hammer.physics.lbl.gov/
• Jona Motta (ETH) here

-- GabrielRamirezSanchez - 2020-02-18