B. Dutta

1. Grand Unified Models, Proton Decay and Phase of B. Dutta Texas A&M University Phys.Rev.Lett.100:181801,2008;arXiv:0805.2988;To appear Collaborator: Yukihiro Mimura ICHEP 08

2. Introduction Flavor Violation in Grand Unified Models Large FCNCs exist for general SUSY breaking masses. Flavor universality of SUSY breaking is assumed to solve the flavor problem. FCNCs can still be induced by RGEs. In MSSM, the quark FCNCs are small due to small CKM mixings. If there is a heavy particle, e.g., heavy right handed neutrino, the loop corrections can induce sizable FCNCs due to large neutrino mixing. (Borzumati-Masiero) The flavor violation effects teach us GUT scale physics

3. FCNC and New Physics The nature of FCNC and CP violation is very important to test the existence of new physics In GUT models, and are correlated. Dutta, Mimura, Phys.Rev.Lett.97:241802,2006. (Belle) The phase of . Is also restricted In this talk : We will study large CP phase in SU(5) and SO(10) GUT models.

4. SM prediction : small! (arXiv: 0712.2397) Large Phase of CP violation in Measurements : 2.2 sigma deviation from the SM (arXiv: 0802.2255) Combined data analysis by UTfit: More than 3 sigma deviation from the SM arXiv:0803.0659

5. b s The gluino box diagram dominates. Mass insertion approximation: s b (Ball-Khalil-Kou)

6. New Physics Contribution in the Mixing Accurate measurement of mass difference is consistent with SM. [Tevatron] One may think that large SUSY contribution is not allowed. However, experimental result of does not constrain size of SUSY contribution much. Due to free phases in the Yukawa coupling There is room for a sizable SUSY contribution. What is this large SUSY contribution?

7. SU(5) GUT Down quarks and lepton doublet are unified in Right-handed neutrino : Both RH down-squarks and LH sleptons can have FCNC effects. (Moroi, Akama-Kiyo-Komine-Moroi, Baek-Goto-Okada-Okumura, …)

8. SU(5) GUT… U is the MNS neutrino mixing matrix. The flavor violating elements in m25 induces Bs mixing

9. SU(5) GUT… Sparticle spectrum is restricted. LHC

10. in Bs mixing 1s 2s

11. Higgsino dark matter region Stau coannihilation region

12. SO(10) GUT Both left- and right-squarks have FCNC effects in SO(10). Flavor violating effects are larger in the box diagram in SO(10).

13. SO(10) GUT… In the SO(10) model, can be large due to left-right box enhancement. can be suppressed by a choice of vacua. For example, If (8,2,1/2) (in 126 Higgs) is light, it generates FCNC in the quark sector Light (8,2,1/2) is needed to suppress proton decay. (Dutta-Mimura-Mohapatra, Phys.Rev.Lett.100:181801,2008. ) (8,2,1/2) introduces flavor violation only in the squark sector

14. If is suppressed by a choice of the vacua, constraint is important. However, can be adjusted to be the experimental rangeunless is enhanced too much by gluino contribution. (this requires small left-right mixing for sbottom) Direct CP violation of can be largefor large

15. bR sL h0, H0, A0 sL bR Large Tanb Double penguin diagram can have large Contribution This diagram’s contribution (~k2tan4b/MA4) Both SU(5) and SO(10) get contribution from this diagram Chargino and gluino mediated penguins contribute Similar single penguin diagrams contribute to Bs mm process (~k2tan6b/MA4) Large Bs phase induces larger Bs mm process even for tanb~20 for universal boundary condition

16. Conclusion • We study the bound of from the LFV in SUSY GUT models. • SUSY spectrum is restricted in SU(5) modelwhere Dirac neutrino is the origin of the large phase. • SO(10) models can generate larger phases. • We expect further accurate experimentsto learn more about the GUT scale physics from the

17. Back up slides

18. (UTfit) (95%)