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

MotivationCombination of oscillation and CEnNS

Future work and conclusion

Non-Standard Interaction of Solar Neutrinos inDark Matter Detectors

Shu Liao

Texas A&M University

Collaboration with: J. Dent, B. Dutta, J. Newstead, L. Strigariand J. Walker

Shu Liao Non-Standard Interaction of Solar Neutrinos in Dark Matter Detectors



Outline

1 MotivationNon-standard interactions of neutrinoTransition probability of solar neutrinoCurrent constrains

2 Combination of oscillation and CEnNSExpected number of events under NSIOscillation effects

3 Future work and conclusionResolving degeneraciesConclusion




Non-standard interactions of neutrinoTransition probability of solar neutrinoCurrent constrains

Non-standard interactions of neutrinos

General four fermion interaction:

Lint = 2p2GF ⌫↵L�

µ⌫�L

⇣✏fL↵� fL�µfL + ✏fR↵� fR�µfR

⌘

⌫�

⌫↵

f

f

= SM +BSM





Differential cross section

Differential cross section of ⌫� + f ! ⌫↵ + f as a function of recoilenergy Er:

d�

dEr=

2

⇡G2

Fmf⇥"��✏fL↵�

��2+��✏fR↵�

��2✓1� Er

E⌫

◆2

� 1

2

⇣✏fL⇤↵� ✏fR↵� + ✏fL↵�✏

fR⇤↵�

⌘ mfEr

E2⌫

#





Cross section on nucleus

✏L↵↵ ! 1

2Z✏pV↵↵ +

1

2(Z+ � Z�) ✏

pA↵↵ +

1

2N✏nV↵↵ +

1

2(N+ �N�) ✏

nA↵↵

✏R↵↵ ! 1

2Z✏pV↵↵ � 1

2(Z+ � Z�) ✏

pA↵↵ +

1

2N✏nV↵↵ � 1

2(N+ �N�) ✏

nA↵↵

d�

dEr! d�

dEr⇥ F 2

�Q2

�

✏pV↵↵ =1

2� 2 sin2 ✓w + 2✏uV↵↵ + ✏dV↵↵

✏pA↵↵ =1

2+ 2✏uA↵↵ + ✏dA↵↵

✏nV↵↵ = �1

2+ ✏uV↵↵ + 2✏dV↵↵

✏pA↵↵ = �1

2+ ✏uA↵↵ + 2✏dA↵↵





Transition probability of solar neutrino

The propagation of neutrino is described by:

H�↵ =

Udiag

✓0,

�m221

2E,�m2

31

2E

◆U †

�

�↵

+p2GF

X

f

nf

⇣�ef�e↵ + ✏f�↵

⌘

U : mixing matrix, �m2ij = m2

i �m2j , nf : number density of

fermion f .Neutrino propagates through the sun adiabatically (diagonalize Hinto UdiagU †):

P�!↵ =��U (t)↵k

��2��A1

jk

��2��A2ij

��2��U (0)�i

��2

A: transition probability between mass eigenstate when resonancehappens.





Current constraints

(a) Gonzalez-Garcia et al,

arXiv:1307.3092

(b) Coloma et al, arXiv:1701.04828

Figure: Current constraints




Expected number of events under NSIOscillation effects

Electron scattering ⌫� + e ! ⌫↵ + e

Figure: Number of events above an equivalent electron recoil energythreshold of 1 keV as each ✏ varies over its allowable range (blue curves).Orange curve: SM contribution.





Nucleus scattering ⌫� +N ! ⌫↵ +N

Figure: Number of events above an equivalent nucleus recoil energythreshold of 1 keV as each e varies over its allowable range (blue curves).Orange curve: SM contribution.





LMA-Dark solution

✓12 ! ⇡

2� ✓12

✓13 ! ⇡ � ✓13

� ! ⇡ � �

�m231 ! ��m2

32

✏ ! �✏⇤

H ! �H⇤

Figure: Number of events for LMA-d solution withdifferent threshold energies.





Threshold

Figure: Number of events with different threshold energies.





Oscillation vs. no oscillation

✏eLee = 0.052 ✏uee = 0.2 ✏dee = 0.17U�mU † +

p2Gfdiag (1, 0, 0) +

p2Gf ✏ 1.10 0.69 0.69

U�mU † +p2Gfdiag (1, 0, 0) +

p2Gf ✏ 1.12 0.67 0.67

U�mU † +p2Gfdiag (1, 0, 0) +

p2Gf ✏ 1.13 0.44 0.44

U�mU † +p2Gfdiag (1, 0, 0) +

p2Gf ✏ 1.72 3.88⇥ 10�5 1.18⇥ 10�3

Table: Ratio to only SM prediction N/NSM





Survival probability due to NSI

Figure: Electron neutrino survival probability for the SM (blue) comparedto cases in of NSI.




Resolving degeneraciesConclusion

Oscillations

Figure: Oscillation experiment can only detect ✏ee � ✏µµ, Coloma et al.2017





Complementarity of various experiments

Reactor + SNS + Solar-DM = constraints on ✏ee � ✏µµ? u and ddegeneracy?

Figure: Combining different result togetherShu Liao Non-Standard Interaction of Solar Neutrinos in Dark Matter Detectors

+

=




Conclusion

1 Direct dark matter searches are able to probe NSI parameterspace that cannot be probed by current neutrino experiments.

1 A low threshold detector is more likely to be able to observesignificant number of events

2 Due to interference between SM and BSM, number ofobserved events can be lower than SM expectations.

2 Uncertainties of additional NSI parameters will not only affectthe detection side, but also affect the solar neutrino flux.


Documents

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