Flavour and Non-universal Gauge Interaction 이강영 (건국대학교) @ 연세대학교 2010. 5. 10.

Based on Kang Young Lee, in progress Kang Young Lee, Phys. Rev. D 76, 117702 (2007) Kang Young Lee, Phys. Rev. D 71, 115008 (2005) J. C. Lee, K. Y. Lee, J. K. Kim, Phys. Lett. B 424, 133 (1998)

Contents Introduction The Model Constraints from Experiment Charged Current Interaction Neutral Current Interaction Summary

Introduction The gauge structure of the Standard Model is just for one generation. There is no reason of the universality in the gauge interaction within the SM. The electroweak gauge interaction is universal with high accuracy. No explanation of the flavour structure is given within the SM framework.

Non-universal strong interaction : top-color Non-universal electroweak interaction : top-flavour Non-universal gauge interaction shows distinctive features of phenomenology. Implication of non-universal gauge interaction has been studied in the flavour physics. Violation of the unitarity of the CKM matrix FCNC at tree level

The Model G = SU(2)l X SU(2)h X U(1)Y SU(2)L X U(1)Y U(1)EM The most general gauge interaction can be reduced to our model. SU(2)1 X SU(2)2 X SU(2)3 X U(1)Y SU(2)l X SU(2)h X U(1)Y

The covariant derivative with The covariant derivative The gauge couplings are parameterized

Spontaneous symmetry breaking by with parameterization Heavy gauge boson masses where

Mass eigenstates in the leading order Model parameters : Perturbativity :

Experimental Constraints A. Electroweak precision test at Z-pole G. Altarelli et al., PLB 349, 145 (1995) K. Y. Lee, PLB 472, 366 (2000) define experimentally

We write Using ZFITTER In our model We derive

LEP Electroweak Working Group, CERN-EP/2003-091

B. Low-energy neutral current data

Particle Data Group, PLB 667, 1 (2008)

C. Atomic parity violation The weak charge of an atom is defined by The correction of the weak charge SM predictions Experimental data

Charged Current Interaction CKM matrix Unitarity relation : Beta decay : K decay : B decay : Unitarity holds.

Non-universal terms in CC interactions separated: where with

Unitarity violated! Modified CKM matrix Effective CKM matrix (modified CKM + W’ effects) Unitarity violated! Unitarity violating term

Neutral Current Interaction Non-universal terms in NC interactions separated: Universal terms where

Non-universal terms where

Diagonalization where FCNC arise!

Lepton flavour violating processes

V32=0.5 V32=0.1 V32=0.01 V32=0.001

Summary Non-universal gauge interaction violates CKM matrix unitarity provides stronger constraints than present experiments such as electroweak precision test, atomic parity violation, low-energy neutral current interactions. LFV may provide more stringent constraints. LFV processes are predicted with allowed parameter set. the unitarity of the CKM matrix the lepton flavour symmetry at tree level