440 likes | 609 Views
Physics with Di- muons at High Luminosity LHC. Ivan Belotelov, Ilya Gorbunov, Viktor Konoplyanikov, Alexander Lanyov, Maria Savina, Sergei Shmatov. Di-muons at LHC What do we learn with di-muons at HL LHC? High Luminosity LHC discovery gains in LHC -> HL LHC new opportunity
E N D
Physics with Di-muons at High Luminosity LHC Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 Ivan Belotelov, Ilya Gorbunov, Viktor Konoplyanikov, Alexander Lanyov, Maria Savina, Sergei Shmatov
Di-muons at LHC • What do we learn with di-muons at HL LHC? • High Luminosity LHC • discovery gains in LHC -> HL LHC • new opportunity • HL LHC Requirements for Detectors • To do list for us Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 2
What Do We Learn now with Dimuons? • Standard Model benchmark channel • x-sections in new energy region • PDF constrains • forward-backward asymmetry and sin2W • Searching for New Physics • Extended gauge models (many models inspired by GUT’s and left-right symmetric models) • Extra Dimensions • Large flat Extra-Dimensions (ADD model): multiple light graviton states • Randall-Sundrum with two branes in curved bulk space: heavy resonance states GKK • TeV-1 Extra dimension Model with fermions are localized at the same (opposite) orbifold point: KK resonance states of Z-bosons • Compositeness Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 3
Status with 2011 Data Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 4
New Limits for New Physics CMS-EXO-10-019 A Z’ with standard-model-like couplings can be excluded below 1940 GeV, the superstring-inspired Z’ below 1620 GeV, and RS Kaluza–Klein gravitons below1450 (1780) GeV for couplings of 0.05 (0.10) PAS-EXO-11-039 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 5
2011 Di-muon Spectrum CMS AN-11-472 ~ TeV Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 6
LHC Luminosity Scenario Phase 2 ~300 fb-1 Mike Lamont, LHCC upgrade session, 16/02/10 3x1033 Hz/cm2 at 7 TeV • 2020-2030 – High Lumi LHC • (High Luminosity (HL-LHC) Chamonix 2011) • need to be able to integrate ~300 fb-1 per year (1 fb-1 per day) peak lumi of 1035 Hz/cm2 • the goal is to achieve 3000/fb in phase 2 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 7
High Luminosity LHC Expectations (3000fb-1)vs LHC Expectations (300 fb-1)(toy estimates) Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 8
HL LHC Motivations for Di-muons • Assume discovery of new phenomena at the LHC : • study of some properties measured at LHC • increase precision of resonance masses, partial width, spin and coupling constants • more precisely measurements of forward-backward asymmetry to distinguish different models • Extend the reach for physics beyond the Standard Model: • Z’, q*, KK modes of graviton and gauge bosons • non-resonance signals from ADD and compositeness • EWK low x-sections processes: • Multiple gauge boson production • Strongly-coupled vector boson system Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 9
Expected Uncertainties: Drell-Yan Example • SM background is also computed for each integrated luminosity scenarios in • dependence of physics tasks. Studies of BG processes assume: • Estimates of rates and optimization S/B-ratio by selection criteria • Estimates of theory- and detector-related uncertainties DY • After selection cuts Drell-Yan dominates over other processes dijets, Wjets, ttbar, WW, WZ, ZZ • Theory: • QCDand EW high-order corrections (K factors) • Parton Distribution Functions (PDF) • QCD scale (Q2) • Detector • Misalignment • B-filed • Pile-up • Trigger and reconstruction • Shape of background Drell-Yan smearing (long-term data) Theory-related uncertaintiesare dominant!!! Need to be improved!!! Statistical errors are higher than detector ones Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012
Drell-Yan Measurements with 300 fb-1 Available masses ~ 3-3.5 TeV CMS PhTDR, V.II AFB stat. Detector systematic effects are small wrt. to statistics at 300 fb-1 need more data !!! syst. CMS AN 2007/003 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 11
Drell-Yan Measurements with 3000 fb-1 Available masses ~ 3-3.5 TeV 300 fb-1 Available masses ~ 4-4.5 TeV 3000 fb-1 V. Konoplianikov Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 12
PDF Uncert. V. Konoplianikov Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 13
QCD Scale Uncert. V. Konoplianikov Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 14
Spin-1 Neutral Resonances : Extended Gauge Models Mass reach for the LHC case (100 fb-1 /year): not better 4.9 TeV/c2 for most optimistic model Mass reach for the HL LHC case (above 300 fb-1 /year: ~ up to 6 TeV/c2 , CMS PhTDR, V.II 10 fb-1 models can be distinguished with AFB from each for resonances with up masses ~ 1 TeV 400 fb-1 Z’ models can be distinguished up to Z’ masses between 2.0-2.7 CMS NOTE 2005/022 SLHC LHC HL LHC Mass reach: ~ 6.5TeV/c2 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 15
Spin-1 Neutral Resonances: TeV-1 Extra Dimensions 5 discovery limit of ZKK Production (M1 model) TeV scale ED’s: KK excitations of the Z LHC CMS PhTDR, V.II S/(√B)>5 for Mll>Mcut 3000 fb-1 LHC Mass reach: ~ 6.0TeV/c2 HL LHC Mass reach: ~ 7.7TeV/c2 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 16
G1μ+μ- Spin-2 Neutral Resonances: RS1 Discovery Limit Di-muon states c=0.01 100 fb-1 c=0.1 100 fb-1 5D curve space with ADS metric: 3(brane)+1(extra)+time! HL LHC vs LHC, 95% CL LHC HL LHC: Increase in reach up to 1.4 TeV 10 fb-1 1000 fb-1 17 CMS PhTDR, V.II Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 17
Spin-1/Spin-2 Discrimination Z vs RS1-graviton CMS PhTDR, V.II Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 18
ADD Discovery Limit Virtual graviton production CMS PhTDR, V.II Confidence limits for LHC 1 fb-1: 3.9-5.5 ТеV for n=6..3 10 fb-1: 4.8-7.2 ТеV for n=6..3 100 fb-1: 5.7-8.3 ТеV for n=6..3 300 fb-1: 5.9-8.8 ТеV for n=6..3 Confidence limits for HL LHC (3000 fb-1): 7 – 12 TeV Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 19
Multiple gauge boson production Production of multiple (nV ≥ 3) gauge bosons provides an important test of the high energy behaviour of weak interactions. Expected rates for 6000 fb-1 (in assumption of 90% efficiency for each lepton): historically N.Shumeiko and Co were interested in this study Triple and quartic gauge boson couplings: 100 fb-1 (14 TeV) 1000 fb-1 (14 TeV) Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 20
Strongly-coupled vector boson system • If there is no light Higgs boson, then the scattering of electroweak gauge • bosons at high energy will show structure beyond that expected in the SM • ρ-like vector resonance (WLZL -> ℓνℓ+ℓ−) • ZLZL scalar resonance • W+L W+L no people involved so far !!! CERN-TH/2002-078 hep-ph/0204087 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 21
Tentative Summary • CMS shows good reconstruction performance • measurements of dimuons: Data vs MC, efficiency, resolution • High Luminosity LHC (1035 Hz/cm2) can allow • to study in details properties of new physics objects (masses, partial width, spin, coupling constants) if they will be discovered • to extend the reach for New Physics – gain in reach: • up to 2 TeV for mass of resonances (~25 % ) • up to 4 TeV for MD(~40 % ) • to explore low x-sections processes (multimuon events etc) • To exploit fully CMS potential the tracker and muon trigger must be changed/hardened/upgraded to maintain performances similar to present ones Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 22
“Hot points” of HL Analysis Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 23
General Detector Requirements We need to keep detector performance for high-luminosity similar to present ones to maintain momentum resolution and efficiency • tracker is a crucial point • punch-trough, bremsstrahlung and EM showering lead to increasing of contaminated events in muon stations • higher occupancy • problems with isolation TeV muon in CMS muon stations • new algorithms (or improvements) • new trigger paths for high energy particles and higher PU (isolation!!!) • better understanding systematic effects Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012
Muon Trigger and Reconstruction Performance CMS AN-11-472 L1_SingleMu12 HLT_Mu40_eta2p1 ||≤2.1, pt > 40 GeV CMS CR-2011/060 (2010 data) Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 25
L1 Trigger vs PU – Single e/g • No increase in single e/g cross section with pileup • Rate increases linearly with luminosity • With current version of e/g trigger, will need higher thresholds, but easier to predict 25 ns 50 ns 50 ns High PU (Fill 2201) Zoomed L. Guiducci Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 26
L1 Trigger vs PU – Single Jets • SingleJet36 cross section increase is very non-linear with increasing PU • High jet thresholds necessary • Jet Energy Corrections (JECs) critical Zoomed L. Guiducci Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 27
L1 Trigger vs PU – Muon • Corrected for RPC pretrigger • no surprises for increasing pileup Zoomed L. Guiducci Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 28
HLT Muon isolation vsPlie-up CMS AN-11-472 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 29
What we need to do?(mainly to update the 2006 PhTDR Results) Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 30
Well-known Strategy • Summaries of physics processes beyond the SM with di-muon in the final state (motivation of HL LHC Physics) (M.Savina/S.Shmatov/N.Shumeiko/????) • Calculation of SM background rates (Drell-Yan etc) with taking into account theoretical uncertainties (V.Konoplianikov/M.Savina/S.Shmatov/ N.Shumeiko/J.Suarez and Co) : - PDF - QCD scale - high-order corrections • Analysis of possibility to measure high-invariant-mass spectrum, multimuon events, forward- backward asymmetry, angular distributions i.e. analysis of statistical and systematic errors (I.Belotelov/I.Gorbunov/A.Lanyov/???) :- trigger cuts, namely isolation criteria etc which is very crucial for punch-trough, bremsstrahlung and EM showering which lead to increasing of contaminated events in muon stations - pileup - misalignment - mass-resolution • Being based on studies above (precise measurements of di-muon spectrum) to explore EWK/QCD and to estimate discovery potential CMS for new physics (I.Gorbunov/A.Lanyov/S.Shmatov/???) Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 31
To Do List • Theory side • Continue to collect physics ideas • Keep under control PDF and QCD uncert.: any suggestions to improve them? • To force using new next-to-next-.. LO generators • CMSSW tool for HL (expected in April ???) • Trigger • To estimate carefully the L1 and HLT rates of • Optimization of thresholds • Until it is not available to estimate pile-up effects (trigger/reco) with the Drell-Yan samples by the standard CMSSW • To revise CMS physics potential (number of expected events, “S/B ratios”, significance ) • EWK/QCD processes • BSM physics Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 32
SW Validation (GEANT-4) SPS muon and pion beams (from 3 GeV up to 300 GeV) • Tests of CMS simulation software (GEANT4-based) used for simulation of CMS detector response 2004 Beam test on -beams 2004 Beam test on -beams Electromagnetic secondaries Punch-through GEANT4-based SW is described experimental data well enough Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 33
Summary of Physics Reach Sergei Shmatov, Prospects of Heavy Di-muons Physics at High Luminosity LHC, RDMS2011, Alushta, 26 May 2011 37 Sergei Shmatov, Physics with Di-muons at High Luminosity LHC, Dubna,11 January 2012 37
Features of high energy muons • Features of a muon of high energy (a few hundred GeV - TeV) • low curvatureof muon trajectory limited pT estimation precision • bremsstrahlung and EM showering contaminated events, problems with isolation • precision is sensitive extremally to detector misalignment TeV muon in CMS muon stations new algorithms (or improvements), new trigger paths for high energy particles (no calorimeter isolation), better understanding systematic effects, tested with MC data and experimental data (cosmic muons and SPS beam)
Development SW for Trigger and Off-line • Development of reconstruction algorithms for high energy muons (up to a few TeV) and pairs of muons (especially in Endcap region) • trigger optimization and validation • offline algorithm development and improvement • algorithm validation with data • studies of influence of systematic effects on reconstruction performance (misalignment, material non-uniformities, B-filed, miscalibration etc) Reconstruction SW was tested with MC data and experimental data (cosmic muons and beam tests) Off-line efficiency • EDrell-Yan events: • efficiency:94÷92 % • mass resolution:3.8÷7.2 % • angle resolution: < 0.5 % for invariant mass 1÷ 5 TeV/с2 The next step (2009-2010): validation of on-line and off-line SW with LHC data
Muon Trigger Efficiency • Trigger cuts for low luminosity: • L1: • single muons: pT > 7 GeV/c, || 2.1 • double muons: pT > (3GeV/c, 3 GeV/c), || 2.4 HTL (L2muonL3tracker): • single muons: pT > 16 GeV/c, || 2.4 • double muons: pT > (3GeV/c, 3 GeV/c), || 2.4 • tracker isolation (R 0.3), no isolation in calorimeter DY HLT:97-98%!! L1: 99%!! HLT efficiency is fallen due to isolation cuts: 96.5% 85 % for 3 TeV Overall efficiency: 76 – 83 % (1-5 TeV)
Performance for Registration of Physics Objects • CMS performance to measure the particle of the Standard model was studies for • different integrated luminosity scenarios starting from the first-LHC run up to ideal • detector conditions. • Each scenario is defined by our current knowledge of the performance of detector systems and reconstruction SW (miscalibration, misalignmnet, trigger efficiency etc) • For example the different misalignment scenario: • First-Data-Taking Scenario (10 pb-1) • Long- Data-Taking Scenario (100 pb-1) • Ideal Detector Scenario Misalignment also does not effect trigger efficiency and mischarged probability 43 SM particles decayed into muon pairs can be measured precisely
Dimuon Total Efficiency acc acc L1 HLT offline acceptance Difference in G* and Z’(DY) production