NMSSM & B-meson Dileptonic Decays

Jin Min Yang

ITP, Beijing

arXiv: 0801.1169 Heng, Wang, Oakes, Xiong, JMY

杨 金 民

Outline

Introduction

NMSSM Model

B Dileptonic Decay

Conclusion

1. Introduction

Some B processes are sensitive to new physics

B-physics is not over (super B-factory, LHCb)

• About B physics

• About NMSSM

Dynamical solution to -problem

Solve little hierarchy problem

What is -problem ?What is little hierarchy problem ?

-problem:

• only dimensionful parameter

• conserving SUSY

• should be at Planck scale

• only dimensionful parameter

• conserving SUSY

• should be at Planck scale

little hierarchy:

• Experimental lower bound mh 114 GeV (95 GeV)

• Theoretical upper bound

mh 90 GeV ( tree-level)

135 GeV ( loop-level)

we need sizable loop effects !

~ 500 GeV

100 GeV

2. NMSSM Model

NMSSM = MSSM +Singlet

Symmetry

Hu·Hd

E6 models (superstring-inspired)

SO(10) U(1) …

string scale

at low energy: S, Hu, Hd + heavy particles

U(1) global PQ

to explicitly break U(1) PQ: cubic term

NMSSM naturally exist ?

Higgs potential:

( 0 )U(1)PQ

( A0, A0 )U(1)R

NMSSM

Spectrum of NMSSM:

• One more CP-odd Higgs (A1)

• One more CP-even Higgs

• One more neutralino

• Before SUSY breaking:

SUSY vacuum: VEVs = 0

EW; Z3 are not broken

• With SUSY breaking:

vacuum: VEVs 0

• EW break at weak scale

SUSY breaking scale (<TeV)

• term is generated at weak scale

How to solve -problem ？

• Z3 symmetry is crucial !

Comment:

Otherwise, introduce a singlet seems no good

(except: in SUSY vacuum EW spontaneously breaking)

• Discrete symmetry may cause new problem

How to solve little hierarchy ？

mh theoretical upper bound

mh experimental lower bound

suppressed !

MSSM:

NMSSM:

has singlet component

MS

SM

fraction of h

V. Barger, et al, hep-ph/0603247

3. B Dileptonic Decay

VKM

In SM:

In SUSY:

g

Assume: soft-terms are flavor universal at GUT scale

flavor mixings occur when evolving down to weak scale

K. Hikasa, M. Kobayashi, PRD36, 724 (1987)

SM: only gauge bosons

SUSY: gauge and Higgs bosons

A1

OPE:

=mb

=mA1

=mW

(integrate out A1)

• A1 is heavy

• A1 is intermediately heavy

• A1 is very light

SU(2) gaugino = 200 GeV

Sfermions = 500 GeV

U(1) gaugino = 100 GeV

• Scan over NMSSM parameter space:

• Keep the points allowed by LEPII

exptdata

No expt data !

Sky-blue points excluded by

Sky-blue points excluded by

4. Conclusion

• In NMSSM a light A1 is allowed • B-meson dileptonic decays can be greatly enhanced in NMSSM

(a) current data has already set on NMSSM

(b) future high precision expt will be crucial test