MSSM Higgs (H/Abb 4b-quarks) For FTK Physics Case (First Look) - PowerPoint PPT Presentation

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MSSM Higgs (H/Abb 4b-quarks) For FTK Physics Case (First Look)

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tan = 30 fixed for all samples. - MA = 200, 300, 500, 700, 900 GeV ... Zoom. Zoom. v10.0.1. v11.0.2. 150 GeV. JET PT. JETB PT. Looks good ... – PowerPoint PPT presentation

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Title: MSSM Higgs (H/Abb 4b-quarks) For FTK Physics Case (First Look)


1
MSSM Higgs (H/Abb 4b-quarks)For FTK
Physics Case(First Look)
  • Kohei Yorita
  • University of Chicago
  • FTK meeting on 12/15, 2005

2
Process
For large values of MA/H and tan? , this channel
strongly enhanced.
BR(??) 10 BR(bb) 90
The main difficulty is QCD bkg.
  • Particular interests
  • Extend the parameter space ?
  • BR measurements, if feasible.

3
A Brief Summary of TDR
In TDR ( PHYS-No-104,1997), this study performed
in 2 steps.
  • W/o trigger No Acceptance losses at the trigger
    level
  • - Idealistic trigger condition, determine
    optimum physics coverage.

- Here is a set of optimized Pt thresholds used
MA(GeV) Jet1(GeV) Jet2(GeV) Jet3(GeV) Jet4(GeV)
200 70 50 30 30
300 100 70 50 30
500 200 100 50 30
700 250 150 50 30
900 300 200 50 30
(2) With LVL1/LVL2 thresholds (as of 199x)
- More realistic scenario. - The Trigger
Menu used for comparisons was (1J180,3J75,4J55).
New (?) one is (1J400,3J165,4J110)
Significantly changed
since then !
4
Conclusions of TDR
5 sigma contour
300 fb-1 MA 300 MA 500
bb (trig) tan? gt 30 tan? gt 30
bb (best) tan? gt 20 tan? gt 29
?? tan? gt 11 tan? gt 15
  • gt The results were fairly
  • negative. (gt5 years ago)
  • gt Numbers w/ trigger will be
  • much worse if current LVL1
  • threshold used.
  • gt Property study will still need
  • this channel.
  • gt We should try as best as we can

5
Signal (H/Abb) Events Generation(with ATLFAST)
A set of parameters to generate (PYTHIA) -
tan? 30 fixed for all samples. - MA 200,
300, 500, 700, 900 GeV - H/A Set force
decay into bb (4b final state) ATLFAST
v10.0.1 and v11.0.2 for comparisons. (50K
events each with v10, 10K events each with v11)
- Setup Athena environment. - Generate
events. - Make CBNT Outputs (AOD as well).
- Develop Analysis Tool. - e.t.c. e.t.c.
There are still many things I do not yet
understand, but yes, this is a
good practice for me !
6
Cross Section
Xsec reported by Pythia was an order of magnitude
lower than TDR. TDR value (I guess) includes the
higher-order effect calculated by so called
HIGLUE, HQQ, HDECAY programs (hep-ph/9510347).
_at_500 GeV tan? 30 ? (H/Abb ??bb) 0.3 pb
? (H/Abb bbbb) 3 pb c.f. TDR value 3.5
pb (PYTHIA a few hundred fb) First, I tried
to reproduce results of TDR (i.e. signal
acceptance and estimate its rate func on
lum), But, things were not easy. Need your
help! next
7
Number of Jets (v10 vs v11)
Generation code I used are exactly the same for
both. Whats happening ? (Something was changed
? Or my bug?)
8
JETB Pt Distributions (AtlfastB)
Before any cuts except njetgt4
  • 2 issues here
  • Higher in v11
  • _at_150 GeV,
  • Gap in v11.
  • ISR/FSR activity
  • is different ???

1st jet Pt
2nd jet Pt
3rd jet Pt
4th jet Pt
9
JET Pt Distributions
Looks smooth _at_ Pt150 GeV. But still much
different b/w v10.0.1 v11.0.2
1st jet Pt
2nd jet Pt
3rd jet Pt
4th jet Pt
10
About Pt150 GeV, JETB vs JETMaybe you could
tell me the difference..
v10.0.1
150 GeV
Zoom
JETB PT
JET PT
v11.0.2
Zoom
Looks good
11
KFJETB Variable (particle ID with
AtlfastB)
v10.0.1
Assume correction factor for jets in AtlffastB
based on this ID. There are too much taus in
v10, V11 seems to be OK.
v11.0.2
12
H/A jj Mass Distributions
Anyway, nice to look at
13
THINGS TO DO
  • Lots of things have to be done (Now just at a
    start point)
  • Need many debugging, plan to solve one by one.
  • More Detailed/Careful Studies !
  • Apply Eriks L1 jet Parameterization.
  • Background Study using Eriks SHERPA samples.
  • More realistic Comparisons to ATLAS baseline
    result.
  • Estimate Observation Significance (func of int.
    Lum.),
  • Any Improvements? (lower tan?
    ?)
  • Plan to finish up all above within a (few) month
    !! ?

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