MC for displaced low mass dimuons (scouting data) UCSB : N. Amin, C. - - PowerPoint PPT Presentation
MC for displaced low mass dimuons (scouting data) UCSB : N. Amin, C. Campagnari, U. Sarica UCSD : V. Krutelyov, M. Masciovecchio, A. Yagil Boston : I. Suarez, A. Tsatsos Rutgers : A. Gandrakota, A. Lath, H. Routray Nebraska : F . Golf July 6, 2020
UCSB: N. Amin, C. Campagnari, U. Sarica UCSD: V. Krutelyov, M. Masciovecchio, A. Yagil Boston: I. Suarez, A. Tsatsos Rutgers: A. Gandrakota, A. Lath, H. Routray Nebraska: F . Golf July 6, 2020
⚫ Look for events with at least 2 displaced muons and an associated
displaced vertex (DV)
between 0 and 11cm
⚫ In addition to model-independent results, provide interpretations for 3
main signal models
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t with EXO MC):
H
Zd Zd
gg → φ
H → ZdZd
B → φ
⚫ Select events with 2 good ScoutingCaloMuons and
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Baseline selections
At least 2 OS muons and 1 DV in collections, then
2017 L1 trigger seeds
OR of
2018 L1 trigger seeds
OR of
Additional selections
⚫ distance(DV, nearest pixel module plane) > 0.05cm ⚫ if DV 𝜍 > 3.5cm, expected pixel hits ≤ observed pixel hits, for both muons ⚫ log10(|𝛦𝜃𝜈𝜈|/|𝛦𝜚𝜈𝜈|) < 1.25 ⚫ |dxy/𝜏dxy| > 2 for both muons ⚫ |dxy|/(𝜍m/pT,𝜈𝜈) > 0.1 for both muons ⚫ After making baseline selections, bin events by
⚫ Fit the background distribution to evaluate exclusion limits ⚫ More analysis details in a previous LL EXO presentation
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𝜍>1 cm 𝜍<1 cm isolated category
⚫ gg → 𝜚
⚫ H → ZdZd
gridpacks/2017/13TeV/powheg/V2/gg_H_quark-mass-effects_ZZ_NNPDF31_13TeV/gg_H_quark-mass- effects_NNPDF31_13TeV_M125/v4/gg_H_quark-mass-effects_NNPDF31_13TeV_M125.tgz) with modified
JHUGen decay files, making SM Z have LL properties, for a given mass and lifetime
⚫ B → 𝜚
requiring two pT>3GeV, |𝜃|<2.4 muons
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⚫ To get an idea of selection efficiencies wrt generation, consider H→ZdZd
(mZd=8GeV, cτ=10mm) events after requiring exactly 2 muons with pT>3GeV, |𝜃| <2.4 at gen. level, then plot efficiencies vs lxy or trailing muon pT
⚫ Due to HLT configuration requiring at least 2 pixel hits, 0 efficiency past lxy~11cm
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Trailing gen. muon pT (GeV)
⚫ We would like to request a 2D grid (mass,cτ) of benchmark samples with 2017 and 2018 conditions
⚫ Scouting collections only stored up to AODSIM, so in principle, we do not need any tiers beyond that ⚫ Links to gridpacks and fragments in the summary table below (subdirectories here) ⚫ If appropriate, will fill out request spreadsheet entries after this meeting ⚫ NOTE: We are still investigating some details with the B→φ model, but wish to proceed with the
generation of the other two
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model gridpack Pythia fragment mass points (GeV) cτ points (mm) conditions gg → φ MG gridpack (set mass) modified (set cτ) 1, 8, 15 1, 10, 100 2017, 2018 H → ZdZd powheg + JHUGen gridpack (set mass, cτ) default 1, 8, 15 1, 10, 100 2017, 2018 B → φ no gridpack modified + gen. filter (set mass, cτ) 1, 2, 4 1, 10, 100 2017, 2018
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⚫ Wei Shi previously reported issues with LLP not being propagated past beam pipe
⚫ We observed the same issue
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⚫ Make matrix of reweighting
between c𝜐={1,10,50,100}mm samples
distributions after analysis selections
⚫ Lower diagonal (reweighting
high c𝜐 to low c𝜐) shows good agreement (compare orange and green) and doesn't suffer from extreme weights
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w(t) = cτ0 cτ1 exp ( ct cτ0 − ct cτ1)
ct = c( ⃗ L xy ⋅ ⃗ pT) m p2
T
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⚫ pass L1 OR: OR of 3 seeds ⚫ pass HLT: DST_DoubleMu3_noVtx_CaloScouting ⚫ pass object sel: event has at least 1 DV and 2 matching muons,
with some baseline cuts on the DV
⚫ pass iso. baseline: isolated baseline selection ⚫ pass extra cuts:
⚫ pass dxy cuts: (|dxy/𝜏dxy| > 2) AND (|dxy|/(𝜍m/pT,𝜈𝜈) > 0.1) for both
muons
⚫ Cuts are cumulative starting with the denominator
(using gen. level quantities):
H → ZdZd