Drell-Yan μ + μ - Studies from Z to TeV Dimitri Bourilkov University of Florida Florida Contribution to Physics TDR SM Review, CPT Week, November 1, 2004, CERN, Geneva

D.Bourilkov Drell-Yan μ + μ - 2 Drell-Yan Muon Pairs: Signal OR Background Test Standard Model at highest momentum transfers; rich search field for new physics (SM, SUSY/BSM groups) Generate with PYTHIA, HERWIG … Muon energies extend to TeV values: Simulation with GEANT4/OSCAR: >Bremsstrahlung, e + e - pair production, muon-nucleus interactions (showering), punch-through etc. FAMOS for TeV muons? > Will need it to cover the large parameter space of scales, masses, couplings etc. for searches (full simulation for the background and selected scales for the signals) ORCA Reconstruction Main SM signal/background: Drell-Yan μ + μ - and  +  - (collaborate with SM / BSM groups); other: WW, cc, bb, tt, fakes, cosmics …

D.Bourilkov Drell-Yan μ + μ - 3 LHC is a Di-lepton Factory “SM (and more) at the LHC” hep-ph/ and CMS-IN- 2000/035; M.Dittmar hep-ex/ Generator level - PYTHIA

D.Bourilkov Drell-Yan μ + μ - 4 Drell-Yan at High Mass

D.Bourilkov Drell-Yan μ + μ - 5 Forward-backward Asymmetry LHC – the initial state is symmetric (pp); no natural quark or anti- quark tagging The harder the quark (a.k.a. “valence”), the higher the chance not to be an anti-quark – use boosted pairs Muon endcaps crucial

D.Bourilkov Drell-Yan μ + μ - 6 PDF Uncertainties LHAGLUE v3 integrated in LHAPDF v3 (D.Bourilkov, C.Group, M.Whalley; and hep-ph/ ) Free download from: durpdg.dur.ac.uk/lhapdf/ PYTHIA, HERWIG or stand-alone mode Rich in new: CTEQ6, MRST, Fermi, Alekhin, Botje, ZEUS2002, H12000 and legacy: CTEQ4, CTEQ5, MRST98, GRV98 PDF sets; successor of PDFLIB Typical PDF uncertainties on xsec <~ 5 % Included in CMKIN_3_2_0, updated for 4_0_0 (DB, Veikko Karimaki, Sergey Slabospitsky)

D.Bourilkov Drell-Yan μ + μ - 7 PDF Uncertainties

D.Bourilkov Drell-Yan μ + μ - 8 High-mass Di-leptons To control the DY signal/background we need both N(N)LO and EW radiative corrections Plan to investigate NLO TEV4LHC workshop: no generator today able to do decently both QCD and EW (follow the developments) DY common for many searches in e + e - μ + μ -  +  -

D.Bourilkov Drell-Yan μ + μ - 9 CMKIN Viewer Visualization of CMKIN events (HEPEVT in ntuples) with ROOT; Rotate in 3D etc available for download from kov/viewcmkin/index.php kov/viewcmkin/index.php

D.Bourilkov Drell-Yan μ + μ - 10 Estimates for DC04  +  - /qq background from GeV TO mass GeV GeV  +  % 8.1 % qq (no isol) 0.3 % 1.5 %

D.Bourilkov Drell-Yan μ + μ - 11 Results on DC04 Data Estimating the CMS di-muon mass resolution directly from early LHC data - use the Drell- Yan Z line-shape to measure the detector performance, and constrain the parton distribution functions at low x Use ~ 1 million fully simulated, fully reconstructed DST events from DC04, available at Florida ( DB, R.Cavanaugh, C.Prescott )

D.Bourilkov Drell-Yan μ + μ - 12 Expected Results for Physics TDR Mass and  efficiency plots for signal/bg Mass resolution for signal (from data)/bg Angular distributions, A FB and spin determination for signal/bg Systematic LHC start-up (inclusion and priority after PRS discussions) : most important / difficult part Detector: alignment, calibration, staging, trigger configuration Theory: PDF uncertainties, NLO effects, EW corrections Background/normalization from data? Z peak, M < GeV

D.Bourilkov Drell-Yan μ + μ - 13 FAMOS Plans Preliminary list of things to do for (TeV) muons in FAMOS (Patrick Janot, DB) Save tracker RecHit’s for muon tracks (in progress – PJ is doing it for all tracks) Propagate muons through tracker & calorimeters with Material Effects Add synchrotron radiation and showering to the Material Effects Save the energy loss (dE/dX, synchrotron radiation, showering) in CaloRecHit’s Propagate the muons through muon chambers with Material Effects Save the RecHits in muon Chambers Global fit for the tracker and muon chamber hits Some of the tools exist already in FAMOS, and could be adapted: showering exists for electrons, doing it for muons is a matter of changing the critical energy; fast propagation through tracker cylinders exist as well multiple scattering and dE/dx exist as well (even if in the tracker only for now) but the rest would have to be developed. FAMOS_1_0_0 running

D.Bourilkov Drell-Yan μ + μ - 14 People from Florida Dimitri Bourilkov, Bockjoo Kim (high-mass); DB, Rick Cavanaugh (Z peak) Muon consultants: Darin Acosta et al. PDF uncertainties: Dimitri Bourilkov, Craig Group Theory consultants: Konstantin Matchev, Rick Field

D.Bourilkov Drell-Yan μ + μ - 15 Outlook High-mass di-leptons test the SM at highest Q 2, and are a rich search field for new physics Many things in common for e + e - μ + μ -  +  - : Drell-Yan signal/background ( collaborate with SM and SUSY/BSM groups, TEV4LHC, LHAPDF, HERA-LHC ) Simulation/Reconstruction of TeV muons (several searches will use them; OSCAR, ORCA, FAMOS) Understanding the most important systematic effects affecting the performance/discovery reach at LHC start-up and how to control them