part i: 3-sigma anomaly of w->tau nu decay in new physics beyond sm

朱守华 , 北京大学物理学院 1

Part I:Part I:3-sigma anomaly of W->tau nu decay3-sigma anomaly of W->tau nu decay

in new physics beyond SMin new physics beyond SM----first clean hint of right-handed charge current?----first clean hint of right-handed charge current?

(hep-ph/0504123)(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•Anomaly indicates right-handed charge current?


Two destinations of puzzles

1: Puzzles stand for new dynamics

•Speed of light as constant

- puzzle

•Sun neutrino missing

2: Puzzles stand for ignorance (both theoretical and expt.)

•CDF di-jet

•Re() in K-system

•b-inclusive production


•ADL final

•O prel.

Anomaly mainly comes from L3


3-sigma anomaly of W->tau measurements, hep-ex/0412015

New physics?


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 Possible explanations in new physics beyond the SM:beyond the SM:

• Oblique-type corrections -> NO!• Flavor-dependent interaction!• 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

Positive!


2-Higgs doublet model (2HDM)2-Higgs doublet model (2HDM)

Negative except for near-degenerate Higgs mass case:

Lebedev etal., PRD62(2000)055014


MSSMMSSM

•Use FeynArts, FormCalc, LoopTools to scan parameter space

•In most cases, delta_new is negative

•In all cases


Anomaly in 2HDM and MSSM Anomaly in 2HDM and MSSM

•It is hard to account for anomaly in two models.

•And it is even harder to account for both W anomaly and neutral data.


Anomalous left- and right-handed couplings Anomalous left- and right-handed couplings

From W->tau nu_tau data:


Constraints from tau-decay dataConstraints 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.

PDG(2004)


Allowed small regions at 95% CL

R: 0-> 0.12

L: 1-> 1.005


Anomalous left- and right-handed couplings for Anomalous left- and right-handed couplings for 3rd generation quark :3rd generation quark :

From B->X_s gamma measurements:

Re(R)< 4 10-3 for Wtb

F. Larios etal., PLB457 (1999)334

|R| 0.12 for W

?


Summary for 1st part (questions)Summary for 1st part (questions)

•How is this anomaly related to fermion mass generation (flavor physics)?

•Is W->tau nu_tau 3-sigma anomaly the first clean signal for the existence of right-handed charge current?

•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)

朱守华Shou-hua Zhu

Peking UniversityJuly 2005@ Tsinghua Univ.


Outline

Why Split SUSY (SS)?How to distinguish SS from TeV SUSY?Chargino pair production at Linear

collidersSummary


Why Split SUSY? (I)

Naturalness problem in the SM mH

phy= 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.


TeV New Physics is an attracting thing (important basis of future colliders), but …


Akani-Hamed,

Pheno2005


S. Dawson, LP2005


TeV SUSY is a beautiful thing (GUT, dark matter, aesthetic …), but …


S. Dawson, LP2005


Shortcomings of TeV SUSY not yet found Higgs small hierarchy

problem (remind: in MSSM at LO mH<MZ) excess flavor and CP violation =>”CP

problem” fast dim-5 proton decay etc. …


Seems MNew Physics >>TeV, did we miss something important? Is that possible that naturalness …?


Why Split SUSY? (II)

Failure of Naturalness of Cosmological Constant ->…


Akani-Hamed,

Pheno2005


Fine tuning =>

God

mechanisms

Assuming UNKNOWN mechanism for finely tuned CC is also applied

to Higgs sector…


GUT and Dark Matter instead of Naturalness are guiding principles Split Supersymmetry

N. Arkani-Hamed &S. Dimopoulos, hep-ph/0405159

Split Supersymmetry can get (a) GUT ( slightly improved) (b) Dark Matter density (c) higher Higgs mass (120~160 GeV) (d) cures to most of TeV SUSY diseases

etc.


Akani-Hamed,

Pheno2005


What is Split SUSY?• SS has only one finely 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:


How to distinguish SS?

• 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

or


Chargino production at LCs(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.


SS Parameter Space & Mixed Region• Assuming gaugino

mass unification and dark matter constraint:

0.094 <DMh2<0.129

G. Giudice & A. Romanino,

hep-ph/0406088


10 TeV

1 TeV

Point Pa: Differential and Forward-backward Asymmetry

(11)


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

M2 and .


Summary for 2nd part

• 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!

part i: 3-sigma anomaly of w->tau nu decay in new physics beyond sm

Documents