CP Conserving (CPC) Benchmark Scenarios

Discovery Potential in CPC scenarios

Discrimination SM or Beyond

The CP Violating CPX Scenario

Discovery Potential in the CPX Scenario

Conclusions

Investigation of the Disovery Potential for Higgs Bosons of the MSSM with ATLAS

Markus Schumacher , Bonn University

June 2004, SUSY04, Tsukuba

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 2

The Higgs sector of the CPC MSSM

t b/ W/Z

h cossin

-sincos

sin()

H sinsin

cos/cos

cos()

A cot tan -----

Couplings MSSM/SM

Two Higgs Doublets 5 physical bosons: h, H, A, H+, H-

at Born level 2 parameters: tan, m A mh < MZ

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

5 parameters fixed in the benchmark scenarios considered

LO-SM-like cross sections

Xsec for gbtH+- from Plehn Program

small small BR(h,bb)

large large BR(h,H,A,bb)

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 3

The 4 CPC Benchmark scenarios

MHMAX scenario ( MSUSY = 1 TeV ) maximal mh < 133 GeV

Nomixing scenario ( MSUSY = 1 TeV ) small mh < 116 GeV

Suggested by Carena et al. , Eur.Phys.J.C26,601(2003)

Masses, coupling and BRs calculated with FeynHiggs (Heinemeyer et al.,Status Mai 04)

Gluophobic scenario

suppressed coupling to gluon

(cancellation of top+stop loops)

small rate for : gg H, e.g. H

MSUSY=350GeV, mh < 119 GeV

Small scenario

coupling to b () suppressed

(canc. sbottom, gluinoloops)

for large tan, MA 150500 GeV

MSUSY = 800 GeV, mh < 123 GeV

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 4

Experimental Issues

key performance numbers obtained from full simulation:

e.g. b-tagging, -id, mass resolutions .…

efficiencies and background expectations from fast

simulations (some key analysis fully checked with full sim.)

int. lumi = 30 fb-1 ~ 2 to3 years at low lumi operation

int. lumi = 300fb-1 = 30 fb-1 @ low lumi. + 270fb-1 @ high lumi

corrections due to larger total decay width taken into account

signal overlap/ mass degeneracy of Higgs bosons considered

discovery = 5 sigma excess using Poissonian statistics

combination of channels with likehood ratio method no systematic uncertainties considered when

evaluating observation potential

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 5

Experimental Inputschannel lumi Mass range Publication

VBF, HWW low M>110 GeV SN-ATLAS-2003-024

ttH, Hbb low+high M>70GeV ATL-PHYS-2003-003

bbH/A low+high 70<M<135GeV

M> 120 GeV

ATL-PHYS-2002-021

ATL-PHYS-2000-005

bbH/Alep.had

had. Had

low

low

M>120GeV

M > 450 GeV

ATL-PHYS-2000-001 ATL-PHYS-2003-008

ATL-PHYS-2003-008

gbtH+-, H,tb low+high M >180 GeV SN-ATLAS-2002-017

ttbW bH+-, H+- low M < 170 GeV ATL-PHYS-2003-58

H/A low+high M > 350 GeV TDR

AZhllbb, Hhhbb

low+high 60 <ML<130 100<MH<360

TDR TDR

H low+high M > 70 GeV TDR

ZZ4l low+high M > 100 GeV TDR

WWll low+high 140<M <120GEV TDR

WHlbb low 70<M<130GeV TDR

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 6

almost gurantees

discovery of at least one

h or H with 30 fb-1

Vector Boson Fusion: 30 fb-1

VBF:qqqqH

Following work by Plehn, Rainwater, Zeppenfeld

studied for MH>110GeVat low lumi running

SM like h with 30 fb-1

ll4

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 7

Light Higgs Boson h: 30 fb-1

difference in covered regions and

contributing channels

mainly due to difference in

mh at same (tan,MA) point

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 8

Small scenario, h: 30 fb-1

nicely covered by enhanced

branching ratio to gauge bosons

hole due to suppressed branching ratio for H to

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 9

Light Higgs Boson h: 300 fb-1

large area covered by several channels stable discovery allows parameter

determination

small uncovered region at low mh = 90 to 100 GeV

hstill sensitive in gluophobic scenario due to associated production Wh, tth

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 10

Heavy Neutral Higgs Bosons

large tan region covered by ppbbH/A, H/A

Rate for

bbA, A ~ (tan)4

coverage similar in 3 other scenarios

running bottom quark mass used

ATLAS preliminary

had.had30fb-1

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 11

Charged Higgs Bosons

gbH+-t

H+-

tbqq

low mass: mH+-< mtop

ggttttH+-bWb

30fb-1

WqqH+-

high mass: mH+-> mtop

transition region around mtop

needs revised experimental analysis

running bottom quark mass used

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 12

Overall Discovery Potential: 300 fb-1

whole plane covered in

all four CP conserving

benchmark scenarios

significant area where

only h is observable

Can we distinguish between SM and extended Higgs sectors by parameter measurements?

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 13

SM or Extended Higgs Sectors?

first look using rate measurements from VBF channels (30fb-1)

R = BR(h) BR(hWW)

=|RMSSM-RSM|exp

only statistical errors considered

assume Higgs mass exactly known

Deviation from SM expectation

potential for discrimination seems promising!

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 14

The CPX scenario MSSM Higgs Sector CP conserving at Born level

CP effects via complex couplings in loops: Complex MSSM

trilinear couplings At, Ab

gluino mass Mgluino

MSUSY = 500 GeV, At=Ab=Mgluino=1 TeV, =2TeV, M2=200GeV

Maximal effect in Higgs sector CPX scenario(suggested by Carena, Ellis, Pilaftsis, Wagner, Phys.Lett B495 155(2000))

maximal phase arg(At)=arg(Ab)=arg(Mgluino)=90 degree

large ratio At/msusy

scan of Born level parameter: tan and MH+-

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 15

Phenomenology in the CPX scenario

all H1, H2 and H3 couple to W and Z

sum rule: i gi (ZZHi) = gSM (ZZH)

both H2 and H3 may decay to

H1H1, ZH1,WW, ZZ

mass eigenstates H1, H2, H3

not equal CP eigenstates h,A,H

low mass for H1 (<50 GeV) not

excluded by OPAL(LEP)

H3H2H1

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 16

Light Higgs Boson H1

border of discovery region at low tanb mostly determined by availability of inputs (VBF >110 GeV, ttH and > 70 GeV)

border at low MH+- due to decoupling of H1 from W,Z and t

30 fb-1 300 fb-1ATLAS preliminary

for VBF channels: assume same efficiencies for

contribution of CP even and CP odd states (needs to be checked) for ttH: efficiencies for CP even and odd bosons are the same

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 17

Heavy Neutral and Charged Higgs Bosons

Charged Bosons Heavy Neutral Bosons

coverage similar to CPC scenariosmore complex in low tanregion due to larger number

of decay channels for H2 and H3

ATLAS preliminary

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 18

Overall Discovery Potential

Zoom

covered by taking into account signal overlap from H1 and H2

MH1: < 70 GeVMH2: 105 to 120 GeVMH3: 140 to 180 GeV small masses not studied yet in ATLAS

tiny „hole“ at border of VBF: H1 H2discovery region

ATLAS preliminary

only H1

only H1

M. Schumacher, ATLAS Higgs Interpretation in the MSSM, SUSY04 , Tsukuba 19

Conclusions

Interpretation of ATLAS Higgs searches in 4 CPC benchmark and the CPX scenario have been performed

CPC scenarios: whole tan vs. MA plane covered,

“wedge region“: only h observable maybe discrimination between SM and beyond by rate measurements

CPX scenario: uncovered region for now at low MH1

because small masses not investigated in ATLAS yet

results need cross check with CPSUPERH (Lee, Pilafstis et al.)

study different values for complex phases

Thanks for programs and discussions to:

Philip Bechtle, Sven Heinemeyer, Tilman Plehn David Rainwater, Michael Spira, ATLAS Higgs working group, …