# Presentation: 676151

##  Exclusive DPE Higgs generators in fast CMS simulation

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

**1. New RP acceptances**
**2.**** Comparison of DPEMC, ExHuMe and EDDE    at parton, hadron and detector levels**
**3. ****Event yields for H->WW**

## DPE Higgs event generators

**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 now**
**in the fast CMS**
**simulation!**

## 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**

## FAMOS: Jet Energy Scale Correction

**0 < |****η****jet****| < 1**

**1 < |****η****jet****| < 2**

**2 < |****η****jet****| < 3**

**|****η****jet****| > 3**

## New RP acceptances for β*=0.55m

**Update of RP acceptances for recent LHC optics**
**(V.Avati and K.Osterberg from Totem exp.)**
**V6.5                          V6.2**
**β*****=0.55m                     0.5m**
**x*=500****μ****m                     0 ****μ****m**
**Beam X-angle=142 ****μ****rad     150 ****μ****rad**
**Proton trajectories simulated with MADX**
**These acceptances recently put in FAMOS. **
**A check performed with flat input ****ξ****, t and ****φ**
**distributions.**

## New RP acceptances: check with flat inputs 

## Mh acceptance

## H->bb, mh=120 GeV: Protons

## H->bb, mh=120 GeV: Protons

## H->bb, mh=120 GeV:  Higgs

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

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

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

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

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

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

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

## 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 stations**
**N****jet ****> ****1**
**2) 45 ****< ****Etj1*****JESCor**** ****< ****85 GeV, Etj2*****JESCor**** ****> ****30 GeV**
**3) |****η****j1,2****| ****< ****2.5**
**4) |****η****j1****-****η****j2****| ****< ****0.8**
**5) 2.8 ****< ****|****φ****j1****-****φ****j2****| ****< ****3.48              **
**6) M****j1j2****/****M****tot ****> ****0.75**
**7) M****j1j2****/****M****miss.mass**** > ****0.8**
**8) N****part****(3****<****|****η****|****<****6) = 0**
**9) 118 ****< ****M****miss.mass ****< ****122 GeV**
**Generator    ****σ****xBR[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!**

## BG to H->bb: Excl.DPE gg->bb, gg->gg

**The main problem: Large cross sections require large statistics to get reliable predictions. More than 1 mil.events analyzed!**
**gg->bb:**
-  DPEMC: ptmin=30GeV: 7.9 ev., ptmin=40GeV: 7.3 ev.  ->7.8** ev**
-  ExHuME: **theta_min=acos(0.75), 60<M<200: 3.1 ev.**
**             ****theta_min=acos(0.65), 60<M<200: 2.1 ev.                    **
**             ****theta_min=acos(0.55), 60<M<200: 2.8 ev.    ****->2.7**** ev**
**             ****theta_min=acos(0.55), 70<M<200: 2.8 ev.**
** **EDDE: ptmin=30GeV: 0.36 ev., ptmin=40 GeV: 0.63 ev. ->   **0.6 ev ** ** **
**gg->gg:**
- DPEMC: ptmin=30GeV: 0.9 ev.                                        ->  **0.9 ev.**
- ExHuME: **theta_min=acos(0.55), 60<M<200: 2.4 ev. **
**            ****theta_min=acos(0.65), 60<M<200: 2.4 ev.    ****-> 2.4**** ev.**
- EDDE: ptmin=30GeV: 0.12 ev., ptmin=40GeV: 0.21 ev.   ->   **0.2 ev**

## 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**** 1****μ**** (pt>14 GeV, |****η****|<2.1) ****or**
**1e (pt>20 GeV, |****η****|<2.5) + 2 quarks (pt>25GeV,|****η****|<5) ****or **
**1****μ**** (pt>10 GeV, |****η****|<2.1) + 2 quarks (pt>25GeV, |****η****|<5)**
**Fully leptonic W decay:**
**2e (pt>17 GeV, |****η****|<2.5) ****or ****2****μ**** (pt>3 GeV, |****η****|<2.1) ****or**
**e****μ**** (pte>17 GeV, |****η****|<2.5 and pt****μ****>3 GeV, |****η****|<2.1) ****or **
**2e (ptmax>29 GeV,|****η****|<2.5) ****or ****2****μ**** (ptmax>14 GeV,|****η****|<2.1) ****or**
**e****μ**** (pte>29 GeV, |****η****|<2.5 or pt****μ****>14 GeV, |****η****|<2.1)**

## Excl. DPE H->WW: Event yield for L=30 fb-1ExhuMe 1.3 and new RP acceptances

-                                                              **semi-lept   fully-lept**
-      **Mh[GeV]  ****σ****XBR[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**

## 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!