Quark-Lepton Complementarity in light of recent T2K & MINOS experiments

1. Quark-Lepton Complementarityin light of recent T2K & MINOS experiments November 18, 2011 YonseiUniversity Sin Kyu Kang (서울과학기술대학교)

2. Outline • Introduction - current status of neutrino mixing angles • Parameterizations of neutrino mixing matrix • Quark mixing angles and Quark-Lepton Complementarity (QLC) • QLC parameterizations and Triminimalparametrization • Predictions of physical observables • Summary

3. Purposes of this work • To investigate whether neutrino mixing matrix based on Quark-Lepton Complementarity (QLC) reflecting GUT relations or quark-lepton symmetry is consistent with current neutrino data or not. • To investigate how we can achieve large values of mixing angle q13so as to accommodate recent T2K or MINOS experimental results. • To point out that nonzero values of q13 can be related to the deviation of q12from maximal mixing or tri-bimaximal mixing

4. Neutrino Mixing Matrix Standard Model states Neutrino mass states Atmospheric angle Reactor angle and Dirac CP phase Solar angle Majorana phases

5. Neutrino mixing anlges before T2K ( Schwetz, Tortola, Valle, New J.Phys.13:063004,2011. )

6. Neutrino data for neutrino mixing angles is consistent with • “Tri-bimaximal mixing” pattern at 2σ It can be derived from some discrete symmetries such as A4, S4 etc.

7. Recent T2K experiment The results show For non-maximal 23 mixing More data needed to firmly establish νe appearance and to better determine θ13

8. Recent MINOS experiment ( 1.7 s excess of ne events )

9. Although TB mixing can be achieved by imposing some flavor symmetries, the current neutrino data indicates that TB is a good zeroth order approximation to reality and there may be deviations from TB in general. • To accommodate deviations from TB, neutrino mixing angles can be parameterized (S.F.King 2008) • The global fit of the neutrino mixing angles can be translated into the 3σ

10. Alternatively, triminimalparametrization has been proposed (Pakvasa, Rodejohann, Weiler, Phys. Rev. Lett.100 ,2008 ) • The neutrino mixing observables up to 2nd order in

11. Quark Mixing Angles • The standard parameterization of VCKM • Current data for quark mixing angles

12. Wolfenstein Parameterization of quark mixing matrix • L. Wolfenstein, Phys. Rev. Lett. 51 (1983)

13. Quark Lepton Complimentarity Lepton mixings Quark mixings Present experimental data allows for relations like: Raidal(2004) Smirnov, Minakata(2004) 'Quark-Lepton Complementarity‘ QLC is well in consistent with the current data within 2σ

14. QLC may serve as a clue to quark-lepton symmetry or • unification. • So, QLC motivates measurements of neutrino mixing angles to at least the accuracy of the measured quark mixing angles. • In the light of QLC, neutrino mixing matrix can be composed of CKM mixing matrix and maximal mixing matrix. • Three possible combinations of maximal mixing and CKM as parametrization of neutrino mixing matrix • (Cheung, Kang, Kim, Lee (2005), Datta, Everett, Ramond (2005) )

15. Among three possible combinations, • Mixing angles in powers of λ • consistent with the current experimental data.

16. Among three possible combinations, • Mixing angles in powers of λ • consistent with the current experimental data, but disfavored by T2K measurement of q13

17. Among three possible combinations, • Mixing angles in powers of λ • consistent with the current experimental data , but disfavored by only T2K measurement of q13 at 90%CL.

18. How to derive those parameterizations • The flavor mixings stem from the mismatch between the LH rotations of the up-type and down-type quarks, and the charged leptons and neutrinos. • In general, the quark Yukawa matrices • Forcharged lepton sector :

19. For neutrino sector : • Introducing one RH singlet neutrino per family which leads to the seesaw mechanism • Rewriting neutrino mass, • In SO(10), Taking symmetric YD , Taking Taking

20. Realistic neutrino mixing matrix, From the empirical relation, We need to modify • Then, neutrino mixing angles becomes

21. In GUT framework, At low energies, the Yukawa operators of the SM (MSSM) are generated from integrating out heavy fields X which lead to GUT relations between q and l • In SU(5) GUT,

22. Then, neutrino mixing angles becomes • In Pati-Salam GUT (Antusch & Sinrath (2009) ), • it is possible to have

23. What if replacing R12(p/4) with tri-bimaximal type ? QLC parameterizations become For realistic GUT relation, we replace UCKMU(l) It is possible to obtain rather large q13 while keeping small deviation of q12

24. Lepton Flavor Violation in the SUSY caused by the misalignment of lepton and slepton mass matrices RG induces Taking (cf)

25. Predictions for Physical Observables • Neutrino mixing probabilities for phased averaged propagation • (Δm2L/4E >>1) (Pakvasa, Rodejohann, Weiler, Phys. Rev. Lett.100 ,2008 )

26. Using the previous formulae, we obtain • Using the best fit values for the parameters

27. The phase-averaged mixing matrix modifies the flavor composition of the neutrino fluxes. • The most common source for atmospheric and astrophysical neutrinos is thought to be pion production and decay. • The pion decay chain generates an initial neutrino flux with a flavor composition given approximately • for the neutrino fluxes : (P. Lipari, M. Lusignoli, and D. Meloni (2007)) • At the Earth :

28. Matching with triminimalparametrization

29. Final Remark • In the light of recent data from T2K, more favorable because it predicts

30. Summary • We have discussed that neutrino mixing matrix based on Quark-Lepton Complementarity (QLC) reflecting GUT relations or quark-lepton symmetry is consistent with global fit to current neutrino data at 2s but some of QLC parameterizations disfavored by T2K • We have shown how we can achieve large values of mixing angle q13so as to accommodate recent T2K or MINOS experimental results. • We have observed that QLC based on GUT relations lead to the relation between nonzero values of q13 and the deviation of q12from maximal mixing or tri-bimaximal mixing