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NMSSM & B-meson Dileptonic Decays. 杨 金 民. Jin Min Yang. ITP, Beijing. arXiv: 0801.1169 Heng, Wang, Oakes, Xiong, JMY. Outline. Introduction NMSSM Model B Dileptonic Decay Conclusion. 1. Introduction. About B physics. B-physics is not over (super B-factory, LHCb). - PowerPoint PPT Presentation
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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