Neutralino Dark Matterin Light Higgs Boson Scenario (LHS)

The scenario is consistent with particle physics experiments

Particle mass b → sγ Bs →μ+μ-

cosmological observations WMAP .

Allowed region can be judged by Bs →μμ& direct detection.

Masaki Asano (SOKENDAI)

Collaborator

S. Matsumoto M. Senami H. Sugiyama

arXiv:0711.3950 

We show

Current Status of Higgs Boson Current Status of Higgs Boson

SM

tan = ratio of vevs, : mixing

Direct LEP Search at LEP

To avoid the strong constraint from ZAh process, we investigate around 90 < mh < 114 GeV in LHS.

MSSM MSSM contains 2 Higgs doublets The coupling can be different!

　 The LEP lower limit may be lower than 114 GeV.

If sin(β-α) is suppressed, we have to take care of the mode

This mode is suppressed due to the P-wave production as long as mA ~ mZ (mA is not too small.)

Introduction

Hierarchy Problem is solved Dark Matter existence GUT is improved as compared to SM

1. Supersymmetry

2. Higgs Potential in MSSM

V=

gauge coupling !

MSSM predicts light Higgs boson mh ~ mZ

1. SM Higgs can not explain the excess, because the number of the excess events corresponds to about 10% of that predicted in the SM 2. MSSM maybe explain this excess if the LHS is realized!

3. LEP has found the excess from expected BG around 98 GeV

Why LHS (90 < mh < 114GeV) in MSSM? Why LHS (90 < mh < 114GeV) in MSSM?

Introduction to LHS

Assuming

Case Case

Usual Scenario LHS Scenario

To realize the LHS, Sin(β-α) has to be small.

sin

SM Higgs limit is applied SM Higgs limit is avoided

CMSSM (Constrained MSSM)

m0, m1/2, A0, tan, sign Usually people use CMSSM as reference model for the MSSM,which is used for collider physics,dark matter phenomenology, etc.

NUHM (Non-Universal Higgs Mass model)

Unfortunately, LHS is not realized.

m0, mHu, mHd, m1/2, A0, sign(

m0, m1/2, A0, tan, , mA

Weak scale

Higgs mass parameters (mHu & mHd)are not necessarily unified with m0.Higgs sector has more freedom!

LHS is realized in the NUHM

1. squark, slepton mass universality are necessary due to suppress unwanted FCNC.2. Universal gaugeino mass is motivated by GUT.3. Universal trilinear coupling is also necessary due to suppress unwanted FCNC.

1, 2, 3

Region consistent with WMAP and other constraints in the LHSRegion consistent with WMAP and other constraints in the LHS

CONSTRAINTS Parameter Scan

80 < mA < 140 GeV

tan = 10

(, A0) GeV = (300, –700), (600, –1000), (700, –1100)

WMAP LEP2 Higgs search Zh/ZH & Ah/AH SUSY particle searches Color/Charged breaking Br( b sγ ) & Br( Bs μ+μ– ) (because of mA ~ mH+ ~ mh, tanβ >>1 )

Pseudo-funnel regionPseudo-funnel region

Mixing regionMixing region

Pseudo-coannihilation regionPseudo-coannihilation region

Too Large μ is not favored (No region for μ > 800 GeV)

The LHS region consistent with the WMAP observation exists!

Can we expect signatures at Dark Matter experiments? Yes, at direct detection experiments for dark matter!

Can we expect signatures at Dark Matter experiments? Yes, at direct detection experiments for dark matter!

Crystal (Ge, Xe, …)

Observing the release energy

1. Dark matter forms the halo associated with Galaxies.2. Solar system moves inside the halo3. Dark matter often passes through the Earth.4. Dark matter sometimes interacts with nucleus inside the detector.

Direct detection observes nuclear recoil as DM scatter of them.

Direct detection Direct detection

… Now, all Higgs are light. Then, prediction for this cross section is large.

1. Small mu is not favored from direct detection experiments.

2. Even for large mu, it is possible to detect the signal at on-going experiments!

SummarySummary Light Higgs Boson Scenario is one of interesting candidates for

new physics at TeV scale. The scenario is consistent with not only particle physics

experiments but also cosmological observations. The scenario predicts a large scattering cross section between

dark matter and ordinary matter, thus it will be tested at present direct detection measurements for dark matter.

Discussion It is interesting to consider the connection between cosmology

and collider physics at LHC & ILC. Almost all SUSY particles are predicted to be light, these

particles will be copiously produced at colliders. Then, it is possible to establish the connection by comparing the

result at colliders and CMB experiments and direct detection measurements for dark matter.