Charged 2006 – Pheno & MC Summary

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Stefano Moretti(Southampton & RAL)

Summary of conclusions: phenomenology and MC generators

Uppsala, 16 September 2006

Charged 2006 – Pheno & MC Summary

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A charged Higgs signal (unlike a neutral one) is always a signal of (whatever) BSM physics !

For example in the MSSM, once a Cinderella now:

Charged 2006 – Pheno & MC Summary

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MC@NLO for pp->tH(->tau-nu) ?

Main background from tt exists in MC@NLO, we are very close to it for the signal !

Analyses use NLO fully inclusive K-factors

Charged 2006 – Pheno & MC Summary

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SUSY virtual effects

In Yukawa vertex – they are detectable ! (Also, survive in decoupled SUSY.)

Charged 2006 – Pheno & MC Summary

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One-loop diagrams in Higgs-W associated production:

They can significantly increase the cross section (light sparticles)

Charged 2006 – Pheno & MC Summary

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And WH channel may well be feasible !

Note: no SUSY enhancement exploited here !

Charged 2006 – Pheno & MC Summary

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SUSY & Higgs interplay

If SUSY kinematically accessible, then real production of sparticles:

Higgses can decay directly to or come from decays of SUSY particles Associated production modes: eg, squark-squark-Higgs SUSY particles suppress or enhance loop induced production or decays

X

X

3χχH

4χχ H/A

102

02

02

Further source of Higges from cascade decays of heavy SUSY particles, in fact Squarks & Gluinos can give many more Higgses than direct production !

101,22

03,4

011

02

χ,χχ,χ

χχ,χ “little cascade from neutralinos/charginos”

“big cascade from neutralinos/charginos”

Higgs into sparticle decay modes can compete with SM modes

Charged 2006 – Pheno & MC Summary

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Useful for filling MSSM decoupling region: eg, SUSY Higgs.

M_2=175 GeV, M_2=350 GeV, mu=150 GeV,M_{slep}=175 GeV, M_{sq, gluino}= 800 GeV

Charged 2006 – Pheno & MC Summary

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Useful for filling MSSM decoupling region: eg, Higgs SUSY.

* Philosophy so far: scan parameter space to optimise leptonic signals (easiest) * Discovery areas for different channels correspond to different SUSY configurations* Problem: discovery plots cannot be superimposed (what’s true LHC potential ?)* Alternatively: adopt SUSY Higgs benchmark points (a la SPS, LHC points, etc.)

M(2)=180 GeV, mu=-500 GeV, m(all sleptons)=250 GeV, M(squark,gluino)=1 TeV

Charged 2006 – Pheno & MC Summary

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SUSY benchmark points in mA tan plane

Snowmass points and slopes: SPShep-ph/0202233

Chosen with SUSY space rather than Higgs space in mind.

9 points: 5+1 mSugra, 2 GSMB, 1 AMSB

Only 4 points feature in usual Higgs plane. 1a, 4 (mSUGRA)7,8 GMSB.

Benchmarks from Carena et al.Eur. Phys. J. C 26 601 (2003) not designedto take light SUSY particle effectsinto account, except in stop loops (gluo-phobic Higgs scenario)

h,A,H,H

h,A,H,H

h,H

h (SM -like)

h,H

h,A,H

H,H

h,H,H

h,H

1a

4

78

Require dedicated study to give suitable set of benchmark points

Charged 2006 – Pheno & MC Summary

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Tools (other than std MCs: PYTHIA, HERWIG, ISAJET)

Charged 2006 – Pheno & MC Summary

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SMadGraph/SMadEvent includes charged Higgs in THDMs, MSSM

Issue:

Battleground •general-purpose: user can pick & mix plus all irr. bkgd implemented but slow/inefficient esp.in PS opt.n•dedicated: fast/efficient but list of processes fixed (authors priorities may not comply with users’ needs)By experience (LEP2, largely Tevatron too) dedicated ones win favour of the exp. Collaborations, one (very personal) question: is it possible to automatise `Forest & Groves’ (minimal G.I. structures) and drop useless bits of codes ?

Charged 2006 – Pheno & MC Summary

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Most include PS matching (ad hoc or via LH accord)

Important:

1) To understand whether differences are genuine – stem from physics differences in matching procedures or are bugs ?

2) Validate against data: not only jet kinematics but also hadronic distributions inside jets (treatment of subleading colour structure in matching for high multeplicities)

Charged 2006 – Pheno & MC Summary

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Tasks from this workshopGeneral consensus emerged on the importance of a full MC@NLO analysis of bg->tH(->tau-nu) & (dominant) tt background: Tilman to consider MC@NLO implementation of signal with Johan^2’s help

SM was volunteered by Tord to setup `task force’ to generate Uppsala Points to study SUSY effects in charged Higgs searches atTevatron/LHC

Johan and Stefan agreed to implant PS & Hadr.n onto their WH(->tau-nu) analysis, ATLAS & CMS very attentive and interested to run a fast detector simulation if full MC analysis points to feasibility – it will be probably a complementary handle for accessing covered MSSM regions Yann volunteered to look at bg tW and see whether there is any potential at Tevatron (may need lumi well in excess of current fb) in testing bg->tH (very large tan(beta) only) and/or ME/PS matching

Charged 2006 – Pheno & MC Summary

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Outlook

Tord: there are enough tasks already assigned here to run cHarged 2007 to check that the homework has been done !

Besides, Uppsala is pretty, people are welcoming, loved the ethanol stuff last night …

… and you are quite a character (must say) ! In fact, thanks to all the organisers for a very enjoyable

workshop !