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Exclusive DPE Higgs generators in fast CMS simulation

Marek Taševský (Physics Inst. Prague)Low-x workshop - Sinaia (Romania) 01/07 2005

1. New RP acceptances2. Comparison of DPEMC, ExHuMe and EDDE at parton, hadron and detector levels3. Event yields for H->WW

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DPE Higgs event generators1.DPEMC 2.4 (M.Boonekamp, T.Kucs) - Bialas-Landshof model + rap.gap survival probability - Herwig for hadronization

2. EDDE 1.2 (V.Petrov, R.Ryutin) - Regge-eikonal approach - Pythia for hadronization

3. ExHuMe 1.3 (J.Monk, A.Pilkington) - KMR model for exclusive diffraction - Pythia for hadronization - Improved unintegrated gluon pdfs

All three models available nowin the fast CMSsimulation!

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Fast CMS simulation: FAMOS_1_2_0_pre4 Main chapters: - Fastcalorimetry, FastElgamma, FastElMatching - FastTsim, FastBtag - FastJets, FastMET, FastHLTMET - FastMuon, FastMuonTrigger - FastTotem (just Roman Pots), FastCastor

Jet algorithm: o) Iterative cone o) Cone radius = 1.0

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FAMOS: Jet Energy Scale Correction

0 < |ηjet| < 1 1 < |ηjet| < 2

2 < |ηjet| < 3 |ηjet| > 3

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New RP acceptances for β*=0.55mUpdate of RP acceptances for recent LHC optics(V.Avati and K.Osterberg from Totem exp.)

V6.5 V6.2β*=0.55m 0.5mx*=500μm 0 μmBeam X-angle=142 μrad 150 μrad

Proton trajectories simulated with MADX

These acceptances recently put in FAMOS. A check performed with flat input ξ, t and φdistributions.

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New RP acceptances: check with flat inputs

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Mh acceptance

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H->bb, mh=120 GeV: Protons

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H->bb, mh=120 GeV: Protons

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H->bb, mh=120 GeV: Higgs

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H->bb, mh=120 GeV: b-quarks after FSR

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H->bb, mh=120 GeV: hadron level

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H->bb, mh=120 GeV: detector level

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H->bb, mh=120 GeV: detector level b-jets

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H->bb, mh=120 GeV: detector level

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ExHuMe: H->WW, mh=140 GeV: leptons

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ExHuMe: H->WW, mh=140 GeV: quarks

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Excl.DPE H->bb: Event yields per L=30 fb-1

• Selection cuts at detector level for mh=120 GeV:0) Both protons accepted in one of two (220,420) RP stations1) Njet > 12) 45 < Etj1*JESCor < 85 GeV, Etj2*JESCor > 30 GeV3) |ηj1,2| < 2.54) |ηj1-ηj2| < 0.85) 2.8 < |φj1-φj2| < 3.48 6) Mj1j2/Mtot > 0.757) Mj1j2/Mmiss.mass > 0.88) Npart(3<|η|<6) = 09) 118 < Mmiss.mass < 122 GeV

Generator σxBR[fb] Acc1*Acc2>0 gg->H->bb gg->bb gg->gg

DPEMC 2.27 50% ? EDDE 1.94 46% ? ExHuMe 1.87 57% ?

No b-tagging yet!

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Excl.DPE H->WW:Event yields per L=30 fb-1

- Both protons accepted in one of two RP’s (220, 420)- (L1 muons taken from FAMOS. El.+quarks correspond to parton level)- Various cut scenarios acc.to current CMS L1 thresholds:

- Semi-leptonic W decay:- 1e (pt>29 GeV, |η|<2.5) or 1μ (pt>14 GeV, |η|<2.1) or- 1e (pt>20 GeV, |η|<2.5) + 2 quarks (pt>25GeV,|η|<5) or - 1μ (pt>10 GeV, |η|<2.1) + 2 quarks (pt>25GeV, |η|<5)

- Fully leptonic W decay:- 2e (pt>17 GeV, |η|<2.5) or 2μ (pt>3 GeV, |η|<2.1) or- eμ (pte>17 GeV, |η|<2.5 and ptμ>3 GeV, |η|<2.1) or - 2e (ptmax>29 GeV,|η|<2.5) or 2μ (ptmax>14 GeV,|η|

<2.1) or- eμ (pte>29 GeV, |η|<2.5 or ptμ>14 GeV, |η|<2.1)

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Excl. DPE H->WW: Event yield for L=30 fb-1

ExhuMe 1.3 and new RP acceptances semi-lept fully-lept Mh[GeV] σXBR[fb] Acc.[%] cms atlas cms atlas

Total

120 0.37 57 0.2 0 1.2 1 1.3 135 0.77 62 0.6 3.1 3.4 140 0.87 63 0.6 1 3.5 3 3.8 150 1.00 66 1.0 4.9 5.3 160 1.08 69 1.0 1 6.0 5 6.6 170 0.94 71 1.0 5.4 5.9 180 0.76 74 0.8 1 4.5 4 4.9 200 0.44 78 0.6 1 2.9 2 3.2

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Summary - Recent versions of DPEMC, EDDE and ExHuMe generators as well as new RP acceptances installed in cms fast simulation - Updated event yields for H->WW channel. They still may increase if the selection cuts are optimized. Bg for H->WW expected to be small. H->bb: selection cuts being optimized. LO+NLO bg under study

- Hot topic these days: Which model gives the best description of data??? The problem is that the only data available are those of Rjj distr. from CDF. And these are very tricky… Very difficult to follow their procedure!