First Look at the Interpretation of ATLAS Higgs Searches in the CPX Scenario of the Complex MSSM

First Look at the Interpretation of ATLAS Higgs Searches in the CPX Scenario of the Complex MSSM

Markus Schumacher , Bonn University

May 13th 2004, CERN

Phenomenology of CPX Scenario

Technicalities

Discovery Potential

Problematic Regions ?

Disclaimer: this are first very preliminary results from a study in progress and NOT official ATLAS results.

Please do note quote plots as ATLAS results!

M. Schumacher, ATLAS Higgs Interpretation in the CPX Scenario of MSSM 2

The CPX scenario

MSSM Higgs Sector CP conserving at Born level

CP effects via complex couplings in loops: ComplexMSSM

relevant for Higgs sector are:

complex trilinear couplings At, Ab and

complex gluino mass paramer Mgluino

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

M2=200GeV, arg(At)=arg(Ab)=arg(Mgluino)=90 degree

Maximal effect in Higgs sector CPX scenario(suggested by Carena, Ellis, Pilaftsis, Wagner et al.)

+ scan of Born level parameter: tan and MH+-

Parameter choice for this first scan:


Phenomenology in the CPX scenario

mixing between CP even and CP odd states

All neutral bosons can couple to pair of W and Z bosons

among themselves Hi,Hj,Hk

Compare to CP Conserving real MSSM:

no born level coupling of A to WW,ZZ, A to hh (HH)

h(H) to Zh(H), A to AZ

Mass eigenstates H1, H2, H3 not equal CP eigenstates h,A,H


H1, H2 and H3 may be produced in VBF, WH and ZH processes decay to pair of W/Zs, pair of Higgs bosons, H+Z bosons

Sum rule for couplings:

i gi (ZZHi) = gSM (ZZHSM) 2 23

H1

H2

H3

Phenomenology in the CPX scenario

H2 and H3 decay into H1H1 and H1Z


Mass of the Lightest Higgs Boson H1

120<MH1<130GeV

110<MH1<120GeV

90<MH1<110GeV

70<MH1<90GeV

40<MH1<70GeV

0<MH1<40GeV

even masses between

0 and 40 GeV

not excluded by LEP

problematic for LHC


Some Technicalities

masses, couplings and branching ratios calculated so far

with FEYNHIGGS 2.1( Heinemeyer, Weiglein et al. )

needs/will be cross checked by CPSUPERH ( A.Pilaftsis, J.S.Lee et al.)

SM like cross sections calculated in leading order with M. Spira‘s programs + CTEQ5L parton density functionscharged Higgs cross sections obtained from T. Plehn‘s program

MSSM cross sections obtained by appropiate correction factors

Gluon fusion: MSSM) = (Hi gg) / (HSM gg) x SM)

VBF,ZH,WH: MSSM) = gHiVV x SM)

ttH/bbH: MSSM) = sffHi x ffH) + pffHi x ffA)

2

2 2

discovery = 5 sigma excess using Poissonian statistics

combination of channels with likehood ratio method

running bottom quark mass usedd for bbH, gbtH+-


Experimental Inputs

efficiencies and background predictions taken from

documented ATLAS analysis (see below) corrections due to larger total decay width taken into account 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

VBF channels: SN-ATLAS-2003-024

ttH, Hbb: ATL-PHYS-2003-003

Charged Higgs: ATL-PHYS-2003-58 (low mass), SN-ATLAS-2002-017, (high mass)

bbH/AATL-PHYS-2002-021 (low mass),ATL-PHYS-2000-005 (high masses)

bbH/Alep. hadATL-PHYS-2000-001 (low m.), ATL-PHYS-2003-008 (high m.)

had. Had: ATL-PHYS-2003-008 ( masses > 450 GeV)

Remaining analysis from ATLAS Detector and Physics Performance TDR


H and HZZ4 leptons

H1GGF+ass. prod.

30fb-1

300fb-1

HiZZ4l

300fb-1

H1

H2

H3


ttH with Hbb and bbH with H

ttH, Hbb

H1 300fb-1

H1 30fb-1

H2 300fb-1

MH1= 70GeVdiscovery region partiallylimited by avaibility

of inputs only down to MH = 70 GeV

(ttH at low tanbbH at low M+-)

Zoom in

bbH1, H1

H1 300fb-1

H1 30fb-1


Weak Vector Boson Fusion

H2

H1

H1 WW

30fb-1

H3

discovery region for low tan limited by avaibility of inputs

only down to 110 GeV

MH1= 110GeVMH2= 110GeV

Zoom in

only studied for low luminosity running so far (forward jet tagging, central jet veto in presence of pile up)


Discovery Potential Light Higgs Boson H1Zoom in

low Higgs masses below 70 GeV

not studied yet in ATLAS

for M H+- >190GeV discovery

in at least two channels

bbH1, H1

ttH1, H1bb

H1 H1ZZ4l

VBF: H1

MH1= 70GeV


Discovery Potential H2 and H3

300fb-1

H2,3 tt

H2WWll

140 GeV< MH

H2H1H1bb

H3H1 Zbb ll

H2H1 Zbb ll

60 GeV< MH1,

200<MH2/3 < 360 GeV

H2/3 30fb-1

H2/3 30fb-1

H2/3 300fb-1

only studied for low luminosity running so far


Charged Higgs Bosons

30fb-1 300fb-1

gbH+-t

H+- , tbqq

low mass: mH+-< mtop

ttH+- b Wb

WlH+-

30fb-1

WqqH+-

30fb-1

high mass: mH+-> mtop

only studied for low

luminosity running so far ( tau tagging for soft taus

in presence of pile up)


Overview of Discovery Potential

Zoom in

Two „problematic“ regions

Discovery of H1

Discovery of H2 and/or H3

Discovery of H+-


Problematic Region I

poor man‘s combination of : H1andH2

H1H2

partially covers hole

see what happens if:

increased lumi. = 60fb-1

extrapolate inputs to MH=100 GeV

H1H2

VBF, HSo far:M>110GeV, int. lumi= 30fb-1

increased coverage + combination covers hole


Problematic Region II

MH1<50GeV

100<MH2<110 GeV

130<MH3<180 GeV

VBF: H230fb-1, 110GeV<MH

Charged Higgs ttH+- b Wb

ttH2, H2bb

try look for H3WWll

WqqH+-30fb-1

Analysis surrounding hole:


Problematic Region II

VBF: H2

30fb-1 60fb-1

110GeV<MH 100GeV<MH

H3WWll3observation with 300fb-1

Charged Higgs30fb-1 100fb-1

other ideas for improved coverage:

investigate high luminosity running for VBF,

lower masses for H3ZH1llbb, try ggH+1 hard jet, H

H+-WH1, Higgs pair production + other new or rare decay modes ??


Conclusions

First preliminary interpretation of ATLAS Higgs searches in CPX scenario has been performed

Good coverage over most of tan vs. MH+- plane,

two problematic regions have been identified and ideas for coverage are on the way study smaller Higgs boson masses at LHC

Investigate „problematic“ regions in more detail

maybe suggest new analysis/ search channels

Crosscheck results with CPSUPERH

Study different values for complex phases

Thanks for programs and discussions to:

Philip Bechtle, Sven Heinemeyer, Tilman Plehn David Rainwater, Michael Spira,…


Backup Slides


Discovery Potential for Heavy Neutrals


OPAL PLOTS

Documents

First Look at the Interpretation of ATLAS Higgs Searches in the CPX Scenario of the Complex MSSM