New Physics Search through → t t → l X / b X Kazumasa OHKUMA (Fukui Tech.) 7/Oct./2005@Shonan...
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Transcript of New Physics Search through → t t → l X / b X Kazumasa OHKUMA (Fukui Tech.) 7/Oct./2005@Shonan...
New Physics Search through → t t → l X / b X
New Physics Search through → t t → l X / b X
Kazumasa OHKUMA (Fukui Tech.)
7/Oct./2005@Shonan Village
hep-ph/0508183
7th International Symposium on Radiative Corrections
PLB593 (2004) 189 & NPB689 (2004) 108
Based on
Z. Hioki ( Tokushima Univ.)B.Grzadkowski (Warsaw Univ.) ,
J.Wudka ( UC Riverside)
In collaboration with
I. Introduction
II. Framework
III. Optimal-Observable Analysis
IV. Summary
Plan of talk
I. Introduction★★StandardStandard Model Model isis composed bycomposed by
Electro-weak theory and Quantum chromodynamics
Highly Successful Model
There are some unsolved problemsBut!!
•Many parameters (Couplings, CKM, ‥‥)•Origin of masses•Hierarchy
New Physics beyond Standard ModelNew Physics beyond Standard Model
Page-17/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
How to search for the signal of new physics?How to search for the signal of new physics?
One of answers:Top quark physics.
Why?
Ans. (1) Heaviest particle observed to date ! !
There are some advantageous properties;
(i) Sensitive to SSB
(ii) Decay as a free quark !
Clear information about top Clear information about top quarkquarkClear information about top Clear information about top quarkquark
τ<<10-23[s]
(2) On top quark sector, C P is negligible in SM ! ! Large CP indicates new physics Large CP indicates new physics
contribution. contribution. Large CP indicates new physics Large CP indicates new physics contribution. contribution.
HiggsHiggs
Page-27/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Interesting option of ILC. Initial CP parity is controllable !!
Only CP-even state at ee collider
We estimateWe estimate
In order to study non-standard effect In order to study non-standard effect
, we focus on
• Couple to CP-odd scalar particles
Statistical Significance of non-Standard Couplings
Photon ColliderPhoton Colliderat
and probeand probeOptimal Beam Polarizations for New Physics Search
Page-37/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
SM Lagrangian is modified by quantum effect of new physics.
Effective Lagrangian approachEffective Lagrangian approach★
W.Buchmuller and D.Wyler, NPB268(1986)621
Model Independent Analysis
Model Dependent Analysis
Complementary relation
• New fields are not in existence under scale.• New heavy particles are decoupled.
Assumption
: SU(3) X SU(2) X U(1) invariant Dim.6 operators: Energy scale of new physics
: non-standard couplings
II. Framework
dk
Page-47/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Effective Operators for γγ→ t t tt interaction (Top EDM)
Top Quark Production Top Quark Production
tt interaction (Contact Interaction)
We found relations between EDM operators and
Contact interaction operators.Page-57/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Relations of OperatorsBianchi identities and SM classical
motion of equations for quark and vector bosons lead us to
Page-67/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Need not to consider Contact Interaction.
× ×
× × ×
× × ××
×
× : No contribution
Effective Operators for →(H)→t t
H interaction (Higgs property)
Effective Operators for t → b W tb W interaction
Top Decay Top Decay
Page-77/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Feynman rules for on-shell photos
(1) C P-conserving tt vertex
(2) C P-violating tt vertex
(1) C P-conserving H vertex
(2) C P-violating H vertex
★ Top Electric Dipole Moment interaction :
★ Higgs Exchange interaction : h
Page-87/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
★ Decay Vertex
Page-97/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Feynman Diagrams for → t tFeynman Diagrams for → t tS.Y.Choi and Hagiwara
P.Poulos and S.D.Rindani
PLB359(1995)369,
PRD56(1997)6835,
etc.
In actual experiment, their mixed signals will be observed !!In actual experiment, their mixed signals will be observed !!
B.Grzadkowski and J.F.Gunion, PLB294(1992)316,G.J.Gounaris and G.P.Tsirigoti,PRD56(1997)3030,E.Asakawa, J.Kamoshita, A.Sugamoto and I.Watanabe,EPJC14(2000)335,E.Asakawa, S.Y.Choi,K.Hagiwara and J.S.Lee, PRD62(2000)115005,R.M.Godbole, S.D.Rindani and R.K.Shigh PRD67(2003)095009, etc.
All possible non-standard interactions are taken into account.
All possible non-standard interactions are taken into account.
Page-107/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
III. Optimal Observable Analysis
Method for estimating the precision of determination of relevant non-standard couplings.
What is Optimal Observable Analysis ?
How to estimate these precision ? J. F. Gunion, et.al, PRL77 (1996) 5172
Suppose following distribution:
: final-state phase space
: known functions ← Calculable
: model-independent coefficients
Cross section
Page-117/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Extract C i using appropriate weighting function
Extract
In general, different choice for the are possible.
There is a unique choice which minimizesthe resultant statistical uncertainty: Ci.
Such function is given by
Page-127/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Inverse matrix of Mij :
Statistical uncertainty of Ci is given by
Calculable
: Total cross section
: Event number
Apply to analysis of final-lepton’s energy and angular distribution for . Page-137/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Application
Final-lepton’s energy and angular distribution
EDM
Higgs
Decay
Calculable
e.g.
Page-147/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Matrix Element Mij
where I,J=1, ,6‥ correspond to SM, 1 , 2 , h1, h2 and d, respectively.
Inverse
EX.
Page-157/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Parameters of Photon collider
: Degree of circular polarization of initial laser
: Initial electron longitudinal polarization
: Degree of linear polarization of initial laser with azimuthal angle
High energy colliding beams of polarized photons are generated by Compton backscattering
Page-167/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Probing optimal photon beam polarizationsEstimate the uncertainty of
couplings
Search for the combinations that make minimal, varying polarization parameters as
Note
Page-177/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Unfortunately !Our results for Xij are very unstable
even a tiny fluctuation of Mij changes Xij significantly !
All the couplings cannot be determined at the same time from only . Refrain from determining all the couplings
at once.
Assumption
Some non-standard couplings Ci have been measured in other processes e.g.
Page-187/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Result
5 and 4 parameters analyses lead to unstable solutions.
3 and 2 parameters analysis give stable solutions within 10% ambiguity
Under the conditions: , ,
Some results are presented hereafter.
3 parameter case : 3 combinations are OK final lepton 1 final bottom 2
2 parameter case : 68 combinations are OK final lepton 39 final bottom 29
Page-197/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
: detection efficiency
Results (3 parameter analysis)
Charged-lepton detectionBottom-quark detection
withwith
(2 of 3)
Not so small !
Page-207/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Results (2 parameter analysis)There are 68 stable solutions.
HoweverAll the stable solutions do not give us good statistical precisions.
Two statistical uncertainties ( , ) satisfy
is minimal
for each pair of and
Page-217/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Results (2 parameter analysis)
mH=300 GeV•Final lepton detection
Page-227/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Results (2 parameter analysis)
mH=300 GeV•Final bottom quark detection
Page-237/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Results (2 parameter analysis)
Independent of Higgs mass•Final lepton detection
Note
There are no combinations which make 2 small (2 < 0.1).
Page-247/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Probe Optimal beam polarizations for New physics search
To study non-standard Effect in top quark production,
IV. Summary
we focus on .
Statistical uncertainties were estimated- CP conserving and violating tt coupling :1,2
- CP conserving and violating H coupling :h1,h2
- anomalous tbW coupling :d
using Optimal Observable method.
Model independent analysis were performed using effective low-energy Lagrangian.
Page-257/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Adjusting beam polarization gives us good statistical precisions: in two parameter analysis
- all non-standard couplings ( except for 2 ) could be determined with accuracy better than 0.1 with a integrated luminosity of 500 fb-1.
- the statistical uncertainty of 2 is still large in this analysis.
We look for anther processes to determine 2.
It is useful to probe the proprieties of Higgs boson couplings.
Page-267/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Back up
Comparing ee and colliders Top quark productions
collideree collider
It is possible to measure tt coupling at both colliders.Within the framework of the effective Lagrangian, we can estimate .
Appendix7/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
In the e e t t l / b X , 2 could not be measured.
Note!
In t t l / b X , 2 could be measuredthough it’s not to be measured precisely.
B.Grazkowski and Z. Hioki, NP B484 (1997) 17, NP B585 (2000) 3L. Brzezinski, Grzadkowski and Z. Hioki, Int. J. Mod. Phys. A14 (1999) 1261
Appendix7/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
1 parameter Optimal Observable analysis
t t l X
e e t t l X
ee colliders will give us slightly good precision.
Comparison of 1 measurement in e e and colliders
Appendix7/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Comparing e e and colliders
ee collider ( e e t t l / b X ) It seems to be slightly favored to measure 1. 2 could not measure in the process.
collider ( t t l / b X )
2 could be measured in the process. (precision is not good) It seems to be very useful for testing the Higgs coupling. Looking for the processes or observable that
make statistical sensitivity small for the measuring 2 is important !
Circular polarization AsymmetryCircular polarization Asymmetry
(-) (-)
Appendix7/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Linear polarization AsymmetryLinear polarization Asymmetry
Appendix7/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections
Results (2 parameter analysis)
mH=300 GeV•Final bottom quark detection
Appendix7/Oct./2005 Shonan Village7th International Symposium on Radiative Corrections