Part I: 3-sigma anomaly of W->tau nu decay in new physics beyond SM ----first clean hint of right-handed charge current? (hep-ph/0504123). 朱守华（ Shou-hua Zhu） Peking University July 2005 @ Tsinghua Univ. 3-sigma anomaly of W->tau nu measurements Anomaly in 2HDM and MSSM
3-sigma anomaly of W->tau nu decay
in new physics beyond SM
----first clean hint of right-handed charge current?
July 2005 @ Tsinghua Univ.
3-sigma anomaly of W->tau nu measurements
Anomaly in 2HDM and MSSM
Anomaly indicates right-handed charge current?
Two destinations of puzzles
1: Puzzles stand for new dynamics
2: Puzzles stand for ignorance (both theoretical and expt.)
Anomaly mainly comes from L3
3-sigma anomaly of W->tau measurements, hep-ex/0412015
3-sigma anomaly of W->tau nu is especially interesting and important:
In SM involved is only pure left-handed charge current
Simpler kinematics and less hadronic uncertainties.
Possible explanations in new physics beyond the SM:
Oblique-type corrections -> NO!
Satisfy neutral-current data (Z-decay) at O(0.1%)
Satisfy tau-> nu_tau l nu_l data
Tan(beta) enhancement flavor interactions
Higgs-fermion Yukawa couplings in 2HDM
Chargino(Neutrolino)-fermion couplings in MSSM
2-Higgs doublet model (2HDM)
Negative except for near-degenerate Higgs mass case:
Lebedev etal., PRD62(2000)055014
Use FeynArts, FormCalc, LoopTools to scan parameter space
In most cases, delta_new is negative
In all cases
Anomaly in 2HDM and MSSM
and neutral data.
Anomalous left- and right-handed couplings
From W->tau nu_tau data:
Constraints from tau-decay data
Delta_L and Delta_R are constrainted by Michel parameters which can be extracted from energy spectrum of daughter letopn in tau->nu_tau l nu_l.
Allowed small regions at 95% CL
dR: 0-> 0.12
dL: 1-> 1.005
Anomalous left- and right-handed couplings for
3rd generation quark :
From B->X_s gamma measurements:
Re(dR)< 4 10-3 for Wtb
F. Larios etal., PLB457 (1999)334
|dR| 0.12 for W
Summary for 1st part (questions)
Is W->tau nu_tau 3-sigma anomaly the first clean signal for the existence of right-handed charge current?
How is this anomaly related to fermion mass generation (flavor physics)?
Will parity be restored at high energy?
Does anomaly indicate the non-universality of gauge interactions for different generation? X.Y. Li and E. Ma, PRL47, 1788(1981)
Part II:Distinguishing Split from TeV (normal)SUSY at ILChep-ph/0407072, PLB604,207(2004)
July 2005@ Tsinghua Univ.
Why Split SUSY (SS)?
How to distinguish SS from TeV SUSY?
Chargino pair production at Linear colliders
Naturalness problem in the SM
mHphy= mH0 +c 2+…, ---new physics scale
=> New Physics should appear at TeV
(TeV/ EW ~10)
Solutions (TeV scale New Physics) to Naturalness problem
TeV SUSY or little Higgs models
Low scale gravity
Composite Higgs boson etc.
S. Dawson, LP2005
S. Dawson, LP2005
Failure of Naturalness of Cosmological Constant ->…
Fine tuning =>
Assuming UNKNOWN mechanism for finely tuned CC is also applied to Higgs sector…
N. Arkani-Hamed &S. Dimopoulos, hep-ph/0405159
(a) GUT ( slightly improved)
(b) Dark Matter density
(c) higher Higgs mass (120~160 GeV)
(d) cures to most of TeV SUSY diseases etc.
SS has only onefinely tuned and light Higgs boson while other scalars are ultra heavy.
Gaugino and Higgsino might be light.
Effective Lagrangian at low energy, besides kinetic terms, after integrating out higher scalar mass:
Precisely measuring Higgsino-gaugino-Higgs vertexes e.g. O(0.1 fb) hep-ph/0407108
Scale of scalars is the most characteristic feature of SS, but directly producing scalars other than light Higgs boson is difficult.
How to determine scalar mass?
(a) Long-lived gluino as a probe of scalar mass at LHC
(b) Chargino pair production at Linear colliders can probe the properties of chargino S.Y. Choi et.al. (1999) and (2000) and is sensitve to sneutrino mass.
G. Giudice & A. Romanino,
Point Pa: Differential and Forward-backward Asymmetry
Point Pa: total
(11), (12) and (22) are all sensitive to sneutrino mass up to 10 TeV for lower M2 and .
Point Pb: Total
(22) Mode is most promising for higher
Chargino pair production can probe the sneutrino mass up to 10 TeV. Need further simulation!
It provides a very crucial method to distinguish Split from TeV (normal) SUSY.
All three modes (11), (12) and (22) should be analyzed.
Current and planning colliders can’t cover all SS parameter space.
Thanks for your attention!