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Anomalous Right-handed Top Quark Couplings Kang Young Lee (Konkuk Univ.) Tevatron B physics workshop @ KISTI 2009. 8. 24.
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Based on J. P. Lee and KYL, arXiv:0809.0751. J. P. Lee and KYL, Phys. Rev. D 78, 056004 (2008). KYL and W. Y. Song, Phys. Rev. D 66, 057901 (2002).
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Contents Introduction B→X s γ decays B q -B q mixing Results Top quark decays Summary -
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Introduction LHC : the top quark factory in a sense More than 10 8 -10 9 top quarks will be produced at LHC in a year (if LHC works at full power). Top quark couplings will be directly tested. Nondiagonal couplings may be observed. Anomalous top quark couplings are worth examining at present.
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The CKM matrix Not directly measured >0.74 without unitarity D0 arXiv: 0803.0739 CDF Note 8968
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Effective Lagrangian V tq eff : measures SM-like left-handed couplings ξ q : measures right-handed couplings Underlying new physics Effective electroweak chiral Lagrangian General Left-Right model (V L CKM ≠V R CKM ) Etc. New particles, neutral current interactions are ignored.
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ΔB=1 effective Hamiltonian O i : SM operators O i ‘ : chiral conjugate operators SM Wilson coefficients B→X s γ decays
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Turn on the right-handed couplings with the new loop functions
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Branching ratio SM prediction at NNLO for M. Misiak and M. Steinhauser, NPB 764, 62 (2007) M. Misiak et al., PRL 98, 022002 (2007). World average value of measurement HFAG
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- Mass and width differences Schreodinger equation Note that B q -B q mixing
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Transition amplitude with
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SM predictions A. Lenz and U. Nierste, JHEP 06, 072 (2007) Measurements HFAG CDF, PRL 97, 242003 (2006) D0, D0 note 5618-CONF
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We obtain ξ b =0 Results
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We obtain ξ s =0
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No CP violation is predicted in B s -B s mixing in the SM. (No phase in V ts and V tb ) Combined analysis of current data of B s -B s mixing tells us that there exists some CP violation. Our prediction of the phase of M 12 s is dominated by the phase of V tq eff. The phase of B d -B d mixing is directly measured. - - -
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ξ b =0 A. Lenz and U. Nierste, JHEP 06, 072 (2007)
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ξ s =0 sin 2β
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Top quark decays Nondiagonal top quark decays which is insensitive to ξ s and directly measure V ts eff. Large deviation from the SM prediction is possible.
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Note that in the SM Can we measure it?
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Model independent study on the anomalous right-handed top quark couplings have been performed. Combined analysis of B→X s γ decays and B q -B q mixing provides valuable information. Constraints on new physics parameters and predictions of departure from the SM are obtained. Nondiagonal top quark decays might examine the tsW coupling independently. Summary -
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