1. Flavour and Non-universal Gauge Interaction
이강영 (건국대학교)
@ 연세대학교

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

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

4. 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.

5. 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

6. 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

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

8. Spontaneous symmetry breaking by
with parameterization
Heavy gauge boson masses
where

9. Mass eigenstates in the leading order
Model parameters :
Perturbativity :

10. 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

11. We write
Using ZFITTER
In our model
We derive

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

14. B. Low-energy neutral current data

16. Particle Data Group, PLB 667, 1 (2008)

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

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

20. Non-universal terms in CC interactions separated:
where
with

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

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

24. Non-universal terms
where

25. Diagonalization
where
FCNC
arise!

26. Lepton flavour violating processes

28. V32=0.5
V32=0.1
V32=0.01
V32=0.001

29. 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