arXiv subjects

V. Belocchi

Publications and source records attributed to V. Belocchi.

4 recordsLinked to original sources

arXiv2026

Relativistic distorted-wave analysis of the missing-energy spectrum measured with monochromatic $\nu_\mu$-$^{12}$C interactions at JSNS$^{2}$

Recently, the JSNS$^2$ collaboration measured for the first time the missing-energy distribution of $^{12}$C using a monochromatic neutrino beam coming from kaon decays at rest. In this work we present the results of an analysis of this spectrum using the relativistic distorted-wave approach. A new parameterization of the spectral function for neutrons in $^{12}$C, which incorporates detailed information from $\left(e,e'p\right)$ experiments with high missing-energy resolution has been used. The role of the recoil of the residual nucleus, final-state interactions, and neutrino event generators are discussed.

nucl-th↗

arXiv2025

MEC-induced two-nucleon emission in neutrino-nucleus scattering

Meson-exchange currents (MEC) play a crucial role in the nuclear response to a leptonic probe, inducing the emission of two nucleons, the so-called 2p2h excitations. Here we report the results of our recent work \cite{Belocchi:2025eix}, in which we evaluated the 2p2h contribution to the $(\nu_\mu,\mu^-p)$ neutrino cross section off a carbon target, which involves the simultaneous detection the outgoing muon and a proton in the final state. This process has recently been measured in long-baseline neutrino experiments, but no truly microscopic calculation for the 2p2h channel existed to be compared with these data until now. The calculation employs fully relativistic two-body currents and is carried out within the Relativistic Fermi Gas framework. It provides a generalization to the weak sector of the electromagnetic inclusive model developed in Ref.~\cite{DePace:2003spn} and an extension of the calculation to enable semi-inclusive predictions. A selection of our results for the semi-inclusive cross section versus the emitted proton variables is presented, both at fixed neutrino energy and folded with the T2K muon-neutrino flux.

nucl-th↗

arXiv2025

Meson-Exchange Currents in Quasielastic Charged-Current Neutrino Reactions with Single-Nucleon Knockout

The effect of meson-exchange currents on charged-current quasielastic neutrino scattering with single-nucleon emission is computed and analyzed within the relativistic Fermi gas model. This contribution arises primarily from the interference between one-body and two-body currents, where the two-body operator excites a 1p1h state in the presence of a second, spectator nucleon. The results obtained show a reduction of the vector, axial and vector-axial transverse response functions and, consequently, a decrease in the total neutrino cross section. In addition to a comparison with the non-relativistic limit, other models are also explored, such as the relativistic mean field model for nuclear matter and the superscaling analysis with relativistic effective mass, both of which yield qualitatively similar results.

hep-ph↗

arXiv2025

Interference between Meson Exchange and One-Body Currents in Quasielastic Electron Scattering

In this work, we present a detailed analysis of the interference between meson exchange currents (MEC) and one-body currents in quasielastic electron scattering, with a focus on the sign of this interference in the transverse response for one-particle emission. We prove that the interference of both the Delta and pion-in-flight currents with the one-body current is negative, leading to a partial cancellation with the seagull current. This is mathematically demonstrated within the framework of the Fermi gas model. By comparing these interferences across various independent particle models, both relativistic and non-relativistic, our results indicate that all studied models display the same behavior. This consistency suggests that the interference is negative in models that do not incorporate tensor correlations in the nuclear wave function.

nucl-th↗