Non Standard Neutrino Interactions

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Oscillation Phenomenology NSI and Neutrino Oscillations Our recent Work Non Standard Neutrino Interactions from Physics beyond the Standard Model J.

1 Oscillation Phenomenology NSI and Neutrino Oscillations Our recent Work Non Standard Neutrino Interactions from Physics beyond the Standard Model J.Baumann Arnold Sommerfeld Center, Department für Physik Ludwig-Maximilians-Universität München 10th IMPRS Workshop, MPI München, 03/11/2008 Summary

2 Outline 1 Oscillation Phenomenology Neutrino Oscillation Experiments Physics beyond the Standard Model 2 NSI and Neutrino Oscillations Definition of NSI Effects of NSI on Experiments 3 Our recent Work Central Question Setup of our Study Results of our Study

3 Outline 1 Oscillation Phenomenology Neutrino Oscillation Experiments Physics beyond the Standard Model 2 NSI and Neutrino Oscillations Definition of NSI Effects of NSI on Experiments 3 Our recent Work Central Question Setup of our Study Results of our Study

4 Neutrino Oscillation Experiments Have shown that neutrinos are massive, mixed particles Have measured m 2 ij and elements of the leptonic mixing matrix U PMNS Still unknown : θ 13 and the Dirac CP-violating phase δ Future experiments : high precision measurements

5 Neutrino Oscillation Experiments Have shown that neutrinos are massive, mixed particles Have measured m 2 ij and elements of the leptonic mixing matrix U PMNS Still unknown : θ 13 and the Dirac CP-violating phase δ Future experiments : high precision measurements

6 Neutrino Oscillation Experiments Have shown that neutrinos are massive, mixed particles Have measured m 2 ij and elements of the leptonic mixing matrix U PMNS Still unknown : θ 13 and the Dirac CP-violating phase δ Future experiments : high precision measurements

7 Neutrino Oscillation Experiments Have shown that neutrinos are massive, mixed particles Have measured m 2 ij and elements of the leptonic mixing matrix U PMNS Still unknown : θ 13 and the Dirac CP-violating phase δ Future experiments : high precision measurements

8 Physics beyond the Standard Model Since neutrinos are massless in the Standard Model Physics beyond the Standard Model (PbSM) PbSM, among other things, typically leads to non standard interactions (NSI) at the source/detector and in neutrino propagation in matter Chance : Discovery of new physics! Drawback : Might lead to confusion in measurements of leptonic parameters! What are the bounds on these new interactions?

9 Physics beyond the Standard Model Since neutrinos are massless in the Standard Model Physics beyond the Standard Model (PbSM) PbSM, among other things, typically leads to non standard interactions (NSI) at the source/detector and in neutrino propagation in matter Chance : Discovery of new physics! Drawback : Might lead to confusion in measurements of leptonic parameters! What are the bounds on these new interactions?

10 Physics beyond the Standard Model Since neutrinos are massless in the Standard Model Physics beyond the Standard Model (PbSM) PbSM, among other things, typically leads to non standard interactions (NSI) at the source/detector and in neutrino propagation in matter Chance : Discovery of new physics! Drawback : Might lead to confusion in measurements of leptonic parameters! What are the bounds on these new interactions?

11 Physics beyond the Standard Model Since neutrinos are massless in the Standard Model Physics beyond the Standard Model (PbSM) PbSM, among other things, typically leads to non standard interactions (NSI) at the source/detector and in neutrino propagation in matter Chance : Discovery of new physics! Drawback : Might lead to confusion in measurements of leptonic parameters! What are the bounds on these new interactions?

12 Outline 1 Oscillation Phenomenology Neutrino Oscillation Experiments Physics beyond the Standard Model 2 NSI and Neutrino Oscillations Definition of NSI Effects of NSI on Experiments 3 Our recent Work Central Question Setup of our Study Results of our Study

13 NSI in the Literature Phenomenological studies on the effect of NSI on oscillation experiments often assume NSI in matter of O(1) are possible NSI at the source/detector are well constrained and therefore negligible We are mainly interested in NSI with matter

14 NSI in the Literature Phenomenological studies on the effect of NSI on oscillation experiments often assume NSI in matter of O(1) are possible NSI at the source/detector are well constrained and therefore negligible We are mainly interested in NSI with matter

15 NSI in the Literature Phenomenological studies on the effect of NSI on oscillation experiments often assume NSI in matter of O(1) are possible NSI at the source/detector are well constrained and therefore negligible We are mainly interested in NSI with matter

16 Definition of the NSI parameter In the Standard Model the neutrino propagation in matter is effected by CC and NC reactions «Ù Ï «Ù We look for modifications contained in the following Lagrangian after EW symmetry breaking L NSI = 2 2G F ɛ f αβ (ν αl γ δ ν βl )(f L,R γ δ f L,R )

17 Definition of the NSI parameter In the Standard Model the neutrino propagation in matter is effected by CC and NC reactions «Ù Ï «Ù We look for modifications contained in the following Lagrangian after EW symmetry breaking L NSI = 2 2G F ɛ f αβ (ν αl γ δ ν βl )(f L,R γ δ f L,R ) «Ù Ù

18 Effects of NSI Direct bounds very weak, e.g. ɛ d R αβ Bounds taken from the following review: [Maltoni; arxiv: ] Large matter NSI (of O(1)) would have dramatic effects

19 Effects of NSI Direct bounds very weak, e.g. ɛ d R αβ Bounds taken from the following review: [Maltoni; arxiv: ] Large matter NSI (of O(1)) would have dramatic effects Blue line : Transition prob. for sin 2 2θ 13 = 0.16 without NSI Red lines : Transition prob. for sin 2 2θ 13 = 0 with NSI Plot taken from : [Kitazawa, Sugiyama, Yasuda; arxiv:hep-ph/ ]

20 Remarks NSI not formulated in an SU(3) C SU(2) L U(1) Y invariant fashion SU(3) C SU(2) L U(1) Y invariant formulation? Effective operator formulation By what extensions of the SM are the NSI actually generated (at tree level)?

21 Remarks NSI not formulated in an SU(3) C SU(2) L U(1) Y invariant fashion SU(3) C SU(2) L U(1) Y invariant formulation? Effective operator formulation By what extensions of the SM are the NSI actually generated (at tree level)?

22 Outline 1 Oscillation Phenomenology Neutrino Oscillation Experiments Physics beyond the Standard Model 2 NSI and Neutrino Oscillations Definition of NSI Effects of NSI on Experiments 3 Our recent Work Central Question Setup of our Study Results of our Study

23 Central question Can we find extensions of the SM that lead to O(1) off-diagonal NSI in matter? We want a description in terms of a full theory, not an effective theory that respects the SU(3) C SU(2) L U(1) Y invariance

24 Central question Can we find extensions of the SM that lead to O(1) off-diagonal NSI in matter? We want a description in terms of a full theory, not an effective theory that respects the SU(3) C SU(2) L U(1) Y invariance

25 Simplest Possibility Promote the neutrino fields to SU(2) L doublets Leads to the operators LLLL or LLf f (after integrating out the newly introduced heavy particles) Generates not only NSI but also new interactions between four charged fermions (4cFI) Related by SU(2) L constraints on the 4cFI put bounds on the NSI, e.g. ɛ e eτ , ɛ q eτ 10 2 Bounds taken from : [Bergmann et al. ; arxiv:hep-ph/ ]

26 Simplest Possibility Promote the neutrino fields to SU(2) L doublets Leads to the operators LLLL or LLf f (after integrating out the newly introduced heavy particles) Generates not only NSI but also new interactions between four charged fermions (4cFI) Related by SU(2) L constraints on the 4cFI put bounds on the NSI, e.g. ɛ e eτ , ɛ q eτ 10 2 Bounds taken from : [Bergmann et al. ; arxiv:hep-ph/ ]

27 Simplest Possibility Promote the neutrino fields to SU(2) L doublets Leads to the operators LLLL or LLf f (after integrating out the newly introduced heavy particles) Generates not only NSI but also new interactions between four charged fermions (4cFI) Related by SU(2) L constraints on the 4cFI put bounds on the NSI, e.g. ɛ e eτ , ɛ q eτ 10 2 Bounds taken from : [Bergmann et al. ; arxiv:hep-ph/ ]

28 Strategy to generate large NSI We impose the following restrictions on our search for SM extensions leading to large off-diagonal NSI in matter No new interactions of 4 charged fermions! No cancellations between diagrams with different messenger particles (needs fine-tuning) Tree-level generation of the NSI through d = 6 and d = 8 operators

29 Strategy to generate large NSI We impose the following restrictions on our search for SM extensions leading to large off-diagonal NSI in matter No new interactions of 4 charged fermions! No cancellations between diagrams with different messenger particles (needs fine-tuning) Tree-level generation of the NSI through d = 6 and d = 8 operators

30 Strategy to generate large NSI We impose the following restrictions on our search for SM extensions leading to large off-diagonal NSI in matter No new interactions of 4 charged fermions! No cancellations between diagrams with different messenger particles (needs fine-tuning) Tree-level generation of the NSI through d = 6 and d = 8 operators

31 Results of our Study at d = 6 At d = 6 we found two SM extensions satisfying our criteria: Charged scalar singlets S i L d=6,as NSI = c d=6,as αβγδ (L c α L β )( L γ L c δ ) Ä Ä Æ Ë Ä «Ä

32 Results of our Study at d = 6 Right handed fermionic singlets N i R L d=6 kin = c d=6,kin αβ ( L α H ) i (H L β ) Ä Ä «Æ Ê À À Ý

33 Results of our Study at d = 6 Rare radiative lepton decays + unitarity of the CKM matrix lead to constraints For both operators we find ɛ d= αβ Both operators lead to NSI at the source and detector (at the same strenght) as well

34 Results of our Study at d = 6 Rare radiative lepton decays + unitarity of the CKM matrix lead to constraints For both operators we find ɛ d= αβ Both operators lead to NSI at the source and detector (at the same strenght) as well

35 Results of our Study at d = 6 Rare radiative lepton decays + unitarity of the CKM matrix lead to constraints For both operators we find ɛ d= αβ Both operators lead to NSI at the source and detector (at the same strenght) as well

36 Results of our Study at d = 8 Since d = 6 did not lead to large NSI and motivated by the literature we extended our study to d = 8 d = 8 is promising because we have two Higgs doublets to select neutrinos (and to avoid 4cFI) We found 3 classes of SM extensions satisfying our criteria

37 Results of our Study at d = 8 Since d = 6 did not lead to large NSI and motivated by the literature we extended our study to d = 8 d = 8 is promising because we have two Higgs doublets to select neutrinos (and to avoid 4cFI) We found 3 classes of SM extensions satisfying our criteria

38 Example of Class 1 L d=8,i d=8,f,i NSI = cαβ (L c α L β )(L γ L c δ )(H H) À Ý Ä «Ä Æ Ë Ë Ä Ä À

39 Example of Class 2 L d=8,ii NSI d=8,f,ii = cαβγδ (L α H )f c f c (H L β ) Ä «Ê Ê Ä Æ Ê Ë Æ Ê À À Ý This class of operators is also possible for right and lefthanded quarks

40 Example of Class 3 L d=8,iii NSI,III = cd=8,f αβγδ (H L c α)(l β H)(L γ L c δ ) Ä Ä «À Ý Ä Æ Ê À ¼ Ë À Ä Æ

41 Results of our Study at d = 8 Constraints on the coefficients of the d = 8 operators can be derived from the constraints on those of the d = 6 operators This leads to ɛ d= αβ All d = 8 operators we considered lead to NSI at the source and detector as well (again at the same strenght)

42 Results of our Study at d = 8 Constraints on the coefficients of the d = 8 operators can be derived from the constraints on those of the d = 6 operators This leads to ɛ d= αβ All d = 8 operators we considered lead to NSI at the source and detector as well (again at the same strenght)

43 Results of our Study at d = 8 Constraints on the coefficients of the d = 8 operators can be derived from the constraints on those of the d = 6 operators This leads to ɛ d= αβ All d = 8 operators we considered lead to NSI at the source and detector as well (again at the same strenght)

44 Summary We have investigated how the NSI get explicitly generated at tree level by extensions of the SM We have derived bounds for the NSI, taking into account their actual production by PbSM

45 Summary We have investigated how the NSI get explicitly generated at tree level by extensions of the SM We have derived bounds for the NSI, taking into account their actual production by PbSM

46 Summary Under the assumptions we made, NSI in matter are much more tightly constrained than assumed in many phenomenological studies In the cases we studied NSI at the source and detector are always produced in association with NSI in matter and should therefore also be taken into account Detailed discussion and results can be found in [S.Antusch, JB, E.Fernández-Martínez; Non-Standard Neutrino Interactions with Matter from Physics Beyond the Standard Model; arxiv: ]

47 Summary Under the assumptions we made, NSI in matter are much more tightly constrained than assumed in many phenomenological studies In the cases we studied NSI at the source and detector are always produced in association with NSI in matter and should therefore also be taken into account Detailed discussion and results can be found in [S.Antusch, JB, E.Fernández-Martínez; Non-Standard Neutrino Interactions with Matter from Physics Beyond the Standard Model; arxiv: ]

48 Summary Under the assumptions we made, NSI in matter are much more tightly constrained than assumed in many phenomenological studies In the cases we studied NSI at the source and detector are always produced in association with NSI in matter and should therefore also be taken into account Detailed discussion and results can be found in [S.Antusch, JB, E.Fernández-Martínez; Non-Standard Neutrino Interactions with Matter from Physics Beyond the Standard Model; arxiv: ]

49 Ä «Ä «Ä Ä Ë Ó Ë Ä Æ Ä Æ Operators at d = 8 d=8,f,i c (L αβ c α L β )(L γ L c δ )(H d=8,f,ii H) c αβγδ (Lα H )f c f c d=8,f,iii (H L β ) c αβγδ (H L c α)(l β H)(L γ L c δ ) Ä «À Ý Ä Æ Ê Ê Ä Ä «À Ý Ä «Ä Ä Ë Ë Æ Ê Ë Æ Ê Æ Ê À ¼ Ë Ä À Ä À À Ý À Ä Æ À Ý Ä ½ Ä ½ Ä «Ä Ë À ¼ Ë Æ Ê À ¼ Æ Ê Ä Ä À À À Ý Ë À À Ý

Symmetry Origin of Observable Nonunitary Neutrino Mixng Matrix in TeV Scale Seesaw Models

Symmetry Origin of Observable Nonunitary Neutrino Mixng Matrix in TeV Scale Seesaw Models Ernest Ma Physics and Astronomy Department University of California Riverside, CA 92521, USA Symmetry Origin of