Probing light mediators in the radiative emission of neutrino pair

Abstract

We propose a new possibility of using the coherently enhanced neutrino pair emission to probe light-mediator interactions between electron and neutrinos. With typical momentum transfer at the atomic $$\mathcal O(1$$ O ( 1 eV) scale, this process is extremely sensitive for the mediator mass range $$\mathcal O(10^{-3} \sim 10^4$$ O ( 10 - 3 ∼ 10 4 ) eV. The sensitivity on the product of couplings with electron ($$g^e$$ g e or $$y^e$$ y e ) and neutrinos ($$g^\nu $$ g ν or $$y^\nu $$ y ν ) can touch down to $$|y^e y^\nu | < 10^{-9} \sim 10^{-19}$$ | y e y ν | < 10 - 9 ∼ 10 - 19 for a scalar mediator and $$|g^e g^\nu | < 10^{-15} \sim 10^{-26}$$ | g e g ν | < 10 - 15 ∼ 10 - 26 for a vector one, with orders of improvement from the existing constraints.

Disentangle neutrino electromagnetic properties with atomic radiative pair emission

“…One possible solution [29] is the radiative emission of neutrino pair (RENP) from excited atoms [30][31][32][33][34][35]. Since atomic transition energies are typically O(eV), close to the neutrino mass values, RENP is an ideal place to test the light mediators that couples with neutrino and electrons [36], including the massless photon.…”

Unique Probe of Neutrino Electromagnetic Moments with Radiative Pair Emission

“…3 shows the 90% C.L. sensitivity curves evaluated in Poisson statistics [32] as a function of T × V . The sensitivity can reach (µ ν ) ij < (1.5 ∼ 3.5) × 10 −11 µ B (( ν ) ij < (2 ∼ 9) × 10 −11 µ B ) for a conservative exposure of 10 days × 100 cm 3 and further touch (0.8 ∼ 2) × 10 −12 µ B ((1.1 ∼ 5.5) × 10 −12 µ B ) for 100 days × 100 cm 3 .…”

“…In this letter, we present a novel way to probe the neutrino magnetic and electric moments by using the radiative emission of neutrino pair (RENP) [28][29][30][31]. The RENP process with O(eV) momentum transfer is a perfect place for probing light mediator interactions [32]. With massless photon being the mediator, the neutrino electromagnetic interactions fall exactly into this category.…”

“…In addition to the SM contribution |M W | 2 [29,32,34], the neutrino magnetic/electric moment first contributes an spin averaged term,…”

Neutrino mass measurement with cosmic gravitational focusing

“…With both superradiance and macroscopic coherent material, the RENP process that is induced by weak interactions can be significantly enhanced [52,53]. Since the typical energy of atomic transitions is intrinsically at the O(eV) scale, RENP can be sensitive to not just light/massless mediators [54][55][56] but also those properties that are attached to the neutrino mass terms [57,58]. In particular, the (10 −3 ∼ 10 −2 ) eV neutrino mass eigenvalues can leave a visible effect in the associated photon spectrum and hence can be measured by RENP [59,60].…”