Coherent and incoherent antineutrino scattering on stable even-even isotopes of molybdenum detectors

TL;DR

The paper develops Standard Model predictions for coherent and incoherent neutral-current neutrino/antineutrino scattering on stable molybdenum isotopes using the deformed shell model within the Donnelly-Walecka multipole framework. By validating DSM-generated $^{92}$Mo structure against spectroscopic data and extending the cross-section calculations to $^{94-100}$Mo, the authors provide detailed $d\sigma/d\omega$ and total cross sections, including the coherent-to-total ratio $\rho$, across the Mo isotopic chain. Key findings show that incoherent strength is dominated by low-lying $1^+$ (Gamow-Teller–like) transitions, while the coherent part scales approximately as $N^2$ and accounts for 86–94% of the total rate depending on isotope. These results establish robust SM baselines for Mo-based CE$\nu$NS detectors, informing experimental analyses, potential BSM interpretations, and refinements of nuclear form factors and weak-interaction parameters such as the neutron radius and the weak mixing angle.

Abstract

The recent observations of the coherent neutrino- and antineutrino-nucleus scattering have opened up a plethora of opportunities to probe physics within standard and non-standard theories of the electroweak interactions. In the present article, our goal is to explore the possibility of using the molybdenum material as detection medium for coherent and incoherent antineutrino- and neutrino- Mo scattering in the ongoing and future coherent elastic neutrino-nucleus scattering (CEνNS) experiments by using relevant (anti-)neutrino beams as e.g. stopped pion-decay neutrino beams, reactor antineutrino beams, astrophysical (solar or supernova) (anti)neutrino beams, etc. Our present coherent and incoherent scattering cross sections of Mo isotopes with neutrinos and antineutrinos are based on the deformed shell model (DSM) that has been previously employed for studying similar processes. On the other hand, in the past, CEνNS events obtained with this model provided us with better fits to COHERENT experimental data compared to phenomenological form factors.

Figures (6)

• Figure 1: HF single-particle spectra for $^{92}$Mo corresponding to lowest energy prolate and oblate configurations. In the figure, circles represent protons and crosses represent neutrons. The HF energy E in MeV, mass quadrupole moment Q in units of the square of the oscillator length parameter and the total azimuthal quantum number K are given in the figure.
• Figure 2: The ground band observed for $^{92}$Mo is compared with the DSM predicted values. The experimental data are taken from nndc
• Figure 3: The differential cross section as a function of the excitation energy $\omega$ for $^{92}$Mo isotope:(a) Upper panel, at incoming antineutrino (left) energy $\varepsilon_{\tilde{\nu}} = 15$ MeV and neutrino (right) energy $\varepsilon_\nu = 15$ MeV, and (b) Lower panel, at incoming antineutrino (left) energy $\varepsilon_{\tilde{\nu}} = 20$ MeV and neutrino (right) energy $\varepsilon_\nu = 20$ MeV, for different excited states of the target nucleus. The contribution of the excitation to $J=1^+$ state is represented in red, to $J=2^+$ in blue, to $J=1^-$ in black, and to $J=2^-$ in cyan. The left side figures are for antineutrino scattering and the right side ones for neutrino scattering.
• Figure 4: The differential cross section as a function of the excitation energy $\omega$ for $^{94,96,98,100}$Mo at incoming antineutrino energy $\varepsilon_{\tilde{\nu}} = 15$ MeV for different excited states. The contribution of the excitation to $J=1^+$ states is represented in red, to $J=2^+$ in blue, to $J=1^-$ in black, and to $J=2^-$ in cyan.
• Figure 5: Summed antineutrino-nucleus (upper panel) and neutrino-nucleus (lower panel) differential scattering cross sections for the $1^+$, $2^+$, $1^-$ and $2^-$ states for the five isotopes $^{92,94,96,98,100}$Mo.