Non-Standard Interaction of Solar Neutrinos in Dark Matter Detectors

Transcription

1 Non-Standard Interaction of Solar Neutrinos in Dark Matter Detectors Texas A&M University Collaboration with: J. Dent, B. Dutta, J. Newstead, L. Strigari and J. Walker

2 Outline Motivation 1 Motivation Non-standard interactions of neutrino Transition probability of solar neutrino Current constrains 2 Expected number of events under NSI Oscillation effects 3 Resolving degeneracies Conclusion

3 Non-standard interactions of neutrinos Non-standard interactions of neutrino Transition probability of solar neutrino Current constrains General four fermion interaction: L int =2 p 2G F L µ L fl f L µ f L + fr f R µ f R f = SM + BSM f

4 Differential cross section Non-standard interactions of neutrino Transition probability of solar neutrino Current constrains Differential cross section of + f! + f as a function of recoil energy E r : d = 2 de r G2 F m f " fl 2 + fr 2 1 E 2 r 1 E 2 fl fr + mf E r fl fr E 2 #

5 Cross section on nucleus Non-standard interactions of neutrino Transition probability of solar neutrino Current constrains L! 1 2 Z pv (Z + R! 1 2 Z pv d de r! d de r F 2 Q 2 Z ) pa N nv (N (Z + Z ) pa N nv N ) na 1 2 (N + N ) na pv = 1 2 2sin 2 w +2 uv + dv pa = ua + da nv = pa = uv +2 dv ua +2 da

6 Transition probability of solar neutrino Non-standard interactions of neutrino Transition probability of solar neutrino Current constrains The propagation of neutrino is described by: apple H = Udiag 0, f m E, m E U + p X 2G F n ef f e + f U: mixingmatrix, m 2 ij = m2 i m 2 j, n f :numberdensityof fermion f. Neutrino propagates through the sun adiabatically (diagonalize H into ŨdiagŨ ): P! = Ũ (t) k 2 A 1 jk 2 A 2 ij 2 Ũ (0) i 2 A: transitionprobabilitybetweenmasseigenstatewhenresonance happens.

7 Current constraints Non-standard interactions of neutrino Transition probability of solar neutrino Current constrains (a) Gonzalez-Garcia et al, arxiv: (b) Coloma et al, arxiv: Figure: Current constraints

8 Electron scattering + e! + e Expected number of events under NSI Oscillation effects Figure: Number of events above an equivalent electron recoil energy threshold of 1 kev as each varies over its allowable range (blue curves). Orange curve: SM contribution.

9 Nucleus scattering + N! + N Expected number of events under NSI Oscillation effects Figure: Number of events above an equivalent nucleus recoil energy threshold of 1 kev as each e varies over its allowable range (blue curves). Orange curve: SM contribution.

10 LMA-Dark solution Expected number of events under NSI Oscillation effects 12! ! 13! m 2 31! m 2 32! H! H Figure: Number of events for LMA-d solution with different threshold energies.

11 Threshold Motivation Expected number of events under NSI Oscillation effects Figure: Number of events with different threshold energies.

12 Oscillation vs. no oscillation Expected number of events under NSI Oscillation effects el ee =0.052 u ee =0.2 d ee =0.17 U mu + p 2G f diag (1, 0, 0) + p 2G f U mu + p 2G f diag (1, 0, 0) + p 2G f U mu + p 2G f diag (1, 0, 0) + p 2G f U mu + p 2G f diag (1, 0, 0) + p 2G f Table: Ratio to only SM prediction N/N SM

13 Survival probability due to NSI Expected number of events under NSI Oscillation effects Figure: Electron neutrino survival probability for the SM (blue) compared to cases in of NSI.

14 Oscillations Motivation Resolving degeneracies Conclusion Figure: Oscillation experiment can only detect ee 2017 µµ,colomaetal.

15 Resolving degeneracies Conclusion Complementarity of various experiments Reactor + SNS + Solar-DM = constraints on ee degeneracy? µµ?uandd

16 Conclusion Motivation Resolving degeneracies Conclusion 1 Direct dark matter searches are able to probe NSI parameter space that cannot be probed by current neutrino experiments. 1 A low threshold detector is more likely to be able to observe significant number of events 2 Due to interference between SM and BSM, number of observed events can be lower than SM expectations. 2 Uncertainties of additional NSI parameters will not only affect the detection side, but also affect the solar neutrino flux.