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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).
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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) Some B processes are sensitive to new 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
little hierarchy: • Experimental lower bound we need sizable loop effects ! mh 114 GeV (95 GeV) • Theoretical upper bound ~ 500 GeV mh 90GeV ( tree-level) 135GeV ( loop-level) 100 GeV
2. NMSSM Model Singlet NMSSM = MSSM + Symmetry Hu·Hd
NMSSM naturally exist ? E6 models (superstring-inspired) string scale SO(10) U(1) … at low energy: S, Hu,Hd+ heavy particles U(1) global PQ to explicitly break U(1) PQ:cubic term
Higgs potential: U(1)PQ ( 0 ) NMSSM U(1)R ( A0, A0 )
Spectrum of NMSSM: • One more CP-odd Higgs (A1) • One more CP-even Higgs • One more neutralino
How tosolve -problem? • Before SUSY breaking: SUSY vacuum: VEVs = 0 EW; Z3 are not broken • With SUSY breaking: SUSY breaking scale (<TeV) vacuum: VEVs 0 • EW break at weak scale • term is generated at weak scale
Comment: • Z3 symmetry is crucial ! 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 MSSM: NMSSM: • mh experimental lower bound has singlet component suppressed !
MSSM fraction of h V. Barger, et al, hep-ph/0603247
In SM: VKM W s b u t c
g W b s d u b t s c
K. Hikasa, M. Kobayashi, PRD36, 724 (1987) Assume: soft-terms are flavor universal at GUT scale flavor mixings occur when evolving down to weak scale
b s SM:only gauge bosons SUSY: gauge and Higgs bosons
b s A1 OPE:
=mW =mA1 (integrate out A1) =mb • A1 is heavy • A1 is intermediately heavy • A1 is very light
Scan over NMSSM parameter space: Sfermions = 500 GeV SU(2) gaugino = 200 GeV U(1) gaugino = 100 GeV • Keep the points allowed by LEPII
expt data No expt data !
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