Recent studies on sparticles and MSSM Higgses at CMS Massimiliano Chiorboli University and INFN Catania

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute OutlineOutline Minimal Supersymmetric Standard Model: theoretical aspects MSSM Higgses A,H l + l - l- -jet 2 -jets A,H 4l + X H + sbottom and gluino reconstruction

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute MSSMMSSM Higgs sector: 2 CP-even: h,H 1 CP-odd: A 2 charged: H Fermions: Fermions: quarks, leptons s = ½ Gauge Bosons: Gauge Bosons: W ±, Z 0,,gluons s = 1 Higgses Higgses s = 0 Sfermions: Sfermions: squarks, sleptons s = 0 Gauginos: Gauginos: Wino, Zino, fotino, gluino s = 1/2 Higgsinos s = 1/2 high tan gg Hbb H mixing

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute The CMS detector

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute A,H A,H Lepton ID from ECAL or -chambers l tagging by IP of the lepton (tracker) -jet: 1 (3) tracks, p T >40 GeV within R(jet,track)<0.03 no track, p T >1 GeV within 0.03 < R < 0.4 no stop mixing M SUSY =1 TeV, =-200 GeV, M 2 =200 GeV, X t =0

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute A,H ll 2 leptons, p t e, > 20 GeV, | e, | < 2.5 b-tagging of the associated jet -tagging through IP of the 2 hard l suppress W l and Z ll bkg no -tagging

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute A,H l + jet One isolated lepton, p T >15 GeV, | |<2.4 -jet, E T >40 GeV, | |<2.4 60° < (l – t-jet) < 175° E t miss > 20 GeV m T (l – E t miss ) < 30 GeV b-tagging of the associated jet m A =140 GeVm A =300 GeV tan =8 tan =15 tan =30 tan =40

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute A,H 2 jets 2 -jets, E T >60 GeV, | |<2.5 q i (jet1) * q i (jet2) < 0 in R<0.03 E t miss > 40 GeV ( -jet1 – -jet2) < 175° No E t miss cut 1 b-jet, E T >30 GeV

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute A,H 4l + X low tan Small H 0,A 0 – coupling SM bkg: ZZ, ZW, Zbb, Zcc, Wtb, tt SUSY bkg: direct sparticles production 4 isolated leptons, p T >10 GeV, | |<2.4 Z-veto 20 GeV < E t miss <130 GeV 2 jets, E T < 50 GeV

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Charged Higgs In some cases (, bb) the neutral Higgs bosons may be hard to distinguish from the Standard Model Higgs at LHC H tb, higher BR, but large irreducible bkg H, lower BR, but more clean environment Observation of charged Higgs physics beyond SM

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute H H 1 -jet, E T >100 GeV, | |<2.5 E t miss > 100 GeV W and top mass reconstruction b-tagging ( -jet, E t miss ) > 60° gg tbH, H

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute 5 contours

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Sparticles searches at CMS Until now, excesses over the SM… New studies: sparticle reconstruction… mSUGRA

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Sparticle reconstruction p p b b 2 isolated leptons, p T >15 GeV, | |<2.4 2 b-jets, p T >20 GeV, | |<2 E t miss > 50 GeV tt, Z+jet, W+jet, ZZ, WW, ZW 10 fb -1 first 6 months at LHC

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute First step: 2 0 l + l p p b b Fit result:

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Sbottom reconstruction E t miss > 150 GeV E t miss > 50 GeV p p b b Assuming M( 1 0 ) known!

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Sbottom mass peak Result of fit: Generated masses:

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Gluino reconstruction p p b b E t miss > 150 GeV Generated mass: Result of fit:

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute Combinatorial suppression sbottom gluino

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute estimation estimation doesnt depend on M( 1 0 ) ! Result of fit:

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute ConclusionsConclusions CMS will be able to discover MSSM Higgses within the first 2 years of run in wide m A -tan regions (A,H Far from bounds (high tan ), mass peaks recontruction possible Decays into sparticles can cover low tan regions Sparticle reconstruction possible within the first 6 months of running for some mSUGRA parameter regions Gluino and sbottom mass peak, dependent on M( 1 0 ) M(gluino) – M(sbottom), independent of M( 1 0 )

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute H tb

Massimiliano Chiorboli Feb 2002 Lake Louise Winter Institute h h excellent ECAL resolution large prompt bkg m H = 120 GeV 100 fb -1 SM MSSM