Toward early physics Shan JIN LianYou SHAN ACCM

Toward early physics Shan JIN Lian-You SHAN ACCM 11@Wu. Han Mar 25, 2009

Outline l l l l Introduction Higgs in W pair Top pair reconstruction SUSY with one lepton W (+jets) production B baryons Exotic Yukawa Summary Wu. Han, Mar 25, 2009 Toward early physics 2

Introduction l The delay is also a chance l l l Better preparation for manpower/resources Better preparation for physics topics Physics topic is still challenging l l l Reachable in 200 pb-1 data Meaningful as physics Feasible in experiment ( analysis ) Available against the strong competitions Suitable to our conditions Wu. Han, Mar 25, 2009 Toward early physics 3

Introduction (ctd) l Impact of 14 -> 10 Te. V run l l Not strange as reality Lower x-sections l l PDF re-weight O(1/2) roughly Softer particles in the event Impact of lower lumi l l Less pile-up effect Less un-physics noises Wu. Han, Mar 25, 2009 Toward early physics 4

Introduction (ctd) l Basing on CSC works l Early physics l l Conventional physics topics l l Extend/amplify, intersect/merge For 30 fb-1 data @ 14 Te. V l l Meaningful, feasible… Ranks are RELATIVELY invariant A stone for your JADEs l l l Rough/biased instead of detailed/full An order from our experiences Suggestions/criticise are welcome Wu. Han, Mar 25, 2009 Toward early physics 5

Higgs search l Always in fashion l l l Not so luminous the golden against the bronze/iron H->WW* via VBF * l l Only for a Higgs with appropriate mass Forward jets against WW/tt backgrounds Delta phi defined control region The ( political ) point to cut in ? Wu. Han, Mar 25, 2009 Toward early physics 6

SUSY search l Inclusive search is most powerful l Large missing Et and jet multiplicity Big backgrounds/JES uncertainties One lepton search * l l l Less dependence on theo paras Easy trigger/reconstruction against BCKGs Sophisticated data driven analyses Wu. Han, Mar 25, 2009 Toward early physics 7

Top reconstruction l Reasonable production l l Reducible Dijets, W/Z + jets backgrounds Good shape of Semi-leptonic events l Detector performance study l l B-tag Lepton isolation Exotic Physics study ? Collaboration with CPPM/SDU ? Wu. Han, Mar 25, 2009 Toward early physics 8

W production l Z/W production l candle in atlas l l l Huge production l l To repeat SM facts as 1’st test of Machines To provide calibration, data quality check 106 events @ 200 pb-1 Theory bases l p. QCD, PDFs Wu. Han, Mar 25, 2009 Toward early physics 9

W production ( ctd ) l W+jets production l Failed in CSC l l l Resumed post-CSC l l No peak to reject Dijets ttbar contamination when big jet-number See W/Z jet group meeting on Mar 12’nd Ratios of multi-jets channels l l l Less experimental uncertainty Enlighten p. QCD studies B-veto dependence ? Wu. Han, Mar 25, 2009 Toward early physics 10

B baryons l Large beauty production x-section l l l However systematics prevent precise phys Peaks to understand detector & muon trigger Sophisticated Prompt J/psi production * l l l Color Octet productionvia polarization measure… 1000000 ϒ(2 S) events ? Less baryons touched ( only Λb ) l l Un-discovered Ξbbq , Ξbcq Leading, needs more study Wu. Han, Mar 25, 2009 Toward early physics 11

Exotic Yukawa l Extra gauge bosons simply at peak l l l High p. T lepton pair ( also neutrino ) VV scattering at high luminosity ( ~100 fb-1 ) Prof. He’s suggestion l l l Top-pion Φ+ in TCM via bc fusion l >=1 pb decaying to tb. X against virtual W l <= Wt prod & ttbar contamination (righthanded peak? ) Charged Higgs H+ in 2 HDM l SUSY-ed FCNC-prod with too complex WH mode l tb suffers ttbar as in CSC ( >= 1 fb-1 ) , but τν ? Possible if very lucky paras Wu. Han, Mar 25, 2009 Toward early physics 12

Summary l Possible physics topics l Top recon for performance W+jet or ϒ(2 S) for publication H->WW* or SUSY for physics l B baryons or Φ+ -> τν for exotics l l l Issues to check l l For which we have experiences/advantages ? Is there suitable point/collaboration to cut in ? Wu. Han, Mar 25, 2009 Toward early physics 13

Summary ( ctd ) l More beyond physics topics l 10 Te. V MC samples feeling l l l Data preparation l l l PDF re-weight tech from 14 to 10 Te. V Reconstruction/analysis Tools/packages on 15. X. Y Transferring to IHEP/China AOD pre-process, Ntuples contents Detector understanding l l Lepton trigger/recon/ID … JES & b-tag Wu. Han, Mar 25, 2009 Toward early physics 14

Many thanks ! Wu. Han, Mar 25, 2009 Toward early physics 15