Abstract

We show that new physics which breaks the left-handed SU(3)Q quark flavor symmetry induces contributions to CP violation in ΔF=1 couplings which are approximately universal, in that they are not affected by flavor rotations between the up and the down mass bases. (Only the short distance contributions are universal, while observables are also affected by hadronic matrix elements.) Therefore, such flavor violation cannot be aligned, and is constrained by the strongest bound from either the up or the down sectors. We use this result to show that the bound from ϵ′/ϵ prohibits an SU(3)Q breaking explanation of the recent LHCb evidence for CP violation in D meson decays. Another consequence of this universality is that supersymmetric alignment models with a moderate mediation scale are consistent with the data, and are harder to probe via CP violating observables. With current constraints, therefore, squarks need not be degenerate. However, future improvements in the measurement of CP violation in D–D¯ mixing will start to probe alignment models.

Highlights

  • Measurements of flavor-changing neutral-current (FCNC) processes in the quark sector put strong constraints on New Physics (NP) at the TeV scale and provide a crucial guide for model building

  • We show that new physics which breaks the left-handed SU (3)Q quark flavor symmetry induces contributions to CP violation in ∆F = 1 couplings which are approximately universal, in that they are not affected by flavor rotations between the up and the down mass bases. (Only the short distance contributions are universal, while observables are affected by hadronic matrix elements.) such flavor violation cannot be aligned, and is constrained by the strongest bound from either the up or the down sectors

  • Applying our argument to rare semileptonic K and B decays, we show how the present and future measurements of these processes constrain the sources of CP violation in rare semileptonic D decays and FCNC top decays

Read more

Summary

INTRODUCTION

Measurements of flavor-changing neutral-current (FCNC) processes in the quark sector put strong constraints on New Physics (NP) at the TeV scale and provide a crucial guide for model building. New flavor breaking sources involving only the SU (2)L doublet quarks Qi (i.e., breaking only the SU (3)Q quark flavor symmetry) cannot be simultaneously diagonalized in both the up and the down quark mass bases, and new contributions to FCNCs are necessarily generated To constrain such models of flavor alignment, processes involving both up and down type quark transitions need to be measured. An additional implication of our result is that in viable flavor alignment models the universal flavor and CP violating phases are naturally small Applying this insight to supersymmetric (SUSY) alignment models leads to the conclusion that the first two generation squarks can have mass splittings as large as 30% at the TeV scale, consistent with mass anarchy at a supersymmetry breaking mediation scale as low as 10 TeV

UNIVERSAL CONTRIBUTIONS TO CP VIOLATION WITH TWO GENERATIONS
UNIVERSAL CONTRIBUTIONS TO CP VIOLATION WITH THREE GENERATIONS
CP violation in third generation transitions
Relating CP violation in hadronic K and D decays
Semileptonic K and D decays
TeV 2 ΛNP
Semileptonic B decays
IMPLICATIONS FOR SUSY MODELS
Findings
CONCLUSIONS

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.