Update on the MSSM Interpretation of

ATLAS Higgs SearchesMarkus Schumacher , Bonn University

ATLAS Physics Workshop, Athens, May 2003

• The Higgs Sector of the MSSM • Updated MSSM Scan• The 4 Benchmark Scenarios• Observation potential for: h, A H, H+-

• SM versus MSSM if only h seen (1st look)• Conclusion and Outlook

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20032

The Higgs Sector of the MSSM• Two Higgs Doublets 5 physical bosons: h, H, A, H+, H-

Parameters of a 2HDM: tanmh , mH, mA, mH+-

SUSY reduces to tan, mA at Born level

• At Born level: mh < MZ

• Large loop corrections mh < 133 GeV (+-3GeV) corrections depend on 5 SUSY parameters: Xt,M0,M2,Mgluino,

• 5 parameters fixed in 4 benchmark scenarios consideredMSSM/SM

t b/ W/Z

h cossin

-sincos

sin()

H sinsin

cos cos

cos()

A cot tan -----

Couplings changed w.r.t. to SM

Enhanced BRbb, for large tan

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20033

Updated Interpretation in the MSSM Most recent calculations for masses a. branching ratios

(HDECAY3.0, Feynhiggs1.3 catch up with LEP)

New and updated analysis: e.g. Vector Boson Fusion channels

More and new benchmark scenarios: (same as final LEP paper)1) MHMAX Scenario (already in TDR)

maximises theoretically allowed region for mh

2) Nomixing Scenario (already in TDR, with MSUSY= 1 TeV ) small mh , now use MSUSY= 2 TeV (1TeV excluded by LEP) 3) Gluophobic scenario 4) Small scenario (see hep/ph0202167 by M.Carena et al. for details)

} New!!! Changed phenomenology of h

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20034

The Gluophobic ScenarioCoupling of Higgs to gluons gHgg supressed due toCancellation of top and stop loops (MSUSY=350GeV)very small cross section for gluon fusion reduced sensitivity for H,ZZ

gHgg MSSM/SM

2

1.2<g2 1.0<g2 <1.2 0.8<g2 <1.0 0.6<g2 <0.8 0.4<g2 <0.6 0.2<g2 <0.4 0.0<g2 <0.2

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20035

The Small ScenarioCoupling of Higgs to b-quarks gHbb supressed due toInfluence of sbottom and gluino loops (MSUSY=800GeV)

Reduced branching ratio H,bb

B(hbb) MSSM/SM

1.4<Bbb 1.2<Bbb <1.4 1.0<Bbb <1.2 0.8< Bbb<1.0 0.6<Bbb<0.8 0.4<Bbb <0.6 0.0<Bbb<0.4

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20036

Mass of the light Higgs boson h

130<Mh

120<Mh<130GeV110<Mh<120GeV

100<Mh<110GeV

90<Mh<100GeV

Mh<90GeV

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20037

Search channels considered• Light CP even Higgs boson (new/updated/TDR)

VBF: qqH(h, hWW, h) (low lumi only) ttH(Hbb) , ttH(hWW), bbh(h) H (inc.+ass.), HZZ4l,WHlbb (low lumi only)

• Heavy Neutral Higgs bosons: channels above + H/A , (lep.+had., had.+had. ) (low lumi only) H/Att, Hhhbb, AZHZhhbbll, WHWWW3l3, HWWll

• Charged Higgs bosons: gbtH+- with H+-tb and one tbl ttbWbH+-blb H+- and t->bqq ttbWbH+-bqqb

• CAVEAT: we are now entering the (tan-MA) plane jungle

(discovery = CLB(poisson)<5.7x10-7)(combination = add significance (>1) in

quadrature)(decay in SUSY particles switched off as in TDR)

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20038

Light Higgs boson h: 30 fb -1

bbh

VBF, h

VBF,h+WW

tthbb

WWhlbb

VBF,hWW

VBF channelscover large part ofMSSM plane

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 20039

Light Higgs boson h: 30 fb -1

bbh

VBF, h

VBF,h+WW

tthbb

WWhlbb

VBF,hWW

VBF channelscover large part ofMSSM plane

combined

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200310

Light Higgs boson h: 10 fb -1

5 discovery

3observation

5 discovery

3observation

Almost no individual channel observable

combination of all channels with signficance > 1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200311

Light Higgs boson h: 300 fb-1

All three

only tthbb

h tthbb

hhZZ4l

For high lumi.: h, tthbb hZZ4l contribute

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200312

h: Number of observable final states

1 channel

2 channels3 channels

4 channels5 channels

several channelsobservable allows parameter determination

300 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200313

Heavy Neutral Higgs Bosons H/A

VBF: H,WW

H/Att

ttH(Hbb), ttH(HWW), H/A, HZZ4l, WHlbb, Hhhbb, AZHZhhbbll, WHWWW3l3,HWWll

4 Scenarios quite similar for H,A,H+- show only MHMAX

Still interesting in general 2HDM

30 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200314

H/Alep had

H/Ahad had

H/A: Tau Channels added

H/Alep had, had had

Both combined

Tau channels New: H/Ahad had Extended: (450 to 800GeV) H/Alep had

30 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200315

H/A: All Channels

VBF: H,WW

H/Att

H/A combined

H/A

ttH(Hbb), ttH(HWW), H/A, HZZ4l, WHlbb, Hhhbb, AZHZhhbbll, WHWWW3l3, HWWll

30 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200316

H/A: 4 Scenarios at 300fb-1

VBF: H,WW

H/Att

H/A

ttH(Hbb), ttH(HWW), H/A, HZZ4l, WHlbb, Hhhbb, AZHZhhbbll, WHWWW3l3, HWWll

H/A combined

300 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200317

Charged Higgs Bosons

gbtH+,-

H+tb,tblgbtH+,- H+-

, tbqqttbWbH+-blb

ttbWbH+-

bqqb

Two regions:a) MH < 170GeV (only

low lumi) ttbWbH+-blb(TDR)ttbWbH+-bqqb(new)b) MH > 180GeV

gbtH+,-,H+tb,tbl(TDR)gbtH+,-,H+-, tbqq(new)

Both new analysis increase coverage(details see Mireia‘s talk)

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200318

How many can be seen: h,H,A,H+- ?

300 fb-11 boson

2 bosons

3 bosonsAll 4 bosons

h only

h,H,A,H+-

h,H,A No holes !Complete plane

covered

h,H,A

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200319

h,H,A,H+- ? 4 Scenarios Compared1 boson

2 bosons

3 bosonsAll 4 bosons

Plane covered in all four benchmark scenarios

300 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200320

Only h seen: is it the SM or the MSSM ?

only h

> 1 Higgs boson

MHMAX scenario, 300fb-1

BR(h) BR(hWW)

BR(hbb) BR(hWW)

R1=

R2=

From VBF

From tth

2=(R1MSSM-R1SM)2exp

=(R2MSSM-R2SM)2exp

> 2 >1

Only statistical error

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200321

ConclusionUpdated interpretation of Higgs searches in 4 benchmark scenarios has been performed

Good coverage of MA-tan plane for all 4 scen., due to complementarity of search channels

New channels for h,H,A,H+- increase sensitivity

Multiple channels observable for light Higgs h seems to allow some discrimination between SM and MSSM

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200322

Next Steps

• Finish study (and write up results obtained so far ?)• Provide „Scan“-Ntuples and Tools • Consider also the case when decay into SUSY particles on• Include systematics and use more sophisticated combination

• Consider CP-violating MSSM and general 2HDM • Continue studies on SM MSSM discrimination

Thanks for discussion and providing info/programs to M. Spira (HDECAY,HIGLU,…), S. Heinemeyer (FeynHiggs) T. Plehn (xsec for gbtH+-), Catherine B.+Mireia D. (BR tbH+-)), especially Elzbieta R.W. and many others from the Higgs group

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200323

Appendix

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200324

h,H,A,H+- ? 4 Scenarios Compared

1 boson

2 bosons

3 bosonsAll 4 bosons

30 fb-1

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200325

h,H,A,H+- ? 4 Scenarios Compared

1 boson

2 bosons

3 bosonsAll 4 bosons

30 fb-1

For light h channels have been combined

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200326

h,H,A,H+- ? 4 Scenarios Compared

1 boson

2 bosons

3 bosonsAll 4 bosons

10 fb-1

For light h channels have been combined

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200327

H/A: 4 Scenarios at 30fb-1

VBF: H,WW

H/Att

H/A

ttH(Hbb), ttH(HWW), H/A, HZZ4l, WHlbb, Hhhbb, AZHZhhbbll, WHWWW3l3, HWWll

H/A combined

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200328

H/A: 4 Scenarios at 10fb-1

VBF: H,WW

H/Att

H/A

ttH(Hbb), ttH(HWW), H/A, HZZ4l, WHlbb, Hhhbb, AZHZhhbbll, WHWWW3l3, HWWll

H/A combined

Markus Schumacher, Universität Bonn ATLAS Physics Workshop, Athens, May 200329

Charged Higgs boson 30 fb-1