Speaker
Description
Neutrino interactions with nuclei are crucial for understanding neutrino properties and for interpreting data from neutrino oscillation experiments. This study focuses on developing a realistic theoretical model, known as the factorized spectral function approach, to investigate neutrino-nucleus quasi-elastic scattering. The spectral function, under certain assumptions, is interpreted as the probability of finding a nucleon in the nucleus with a given binding energy and momentum. The focus of this research is on 40Ar, a key target nucleus in several neutrino experiments. Within the Plane Wave Impulse Approximation (PWIA), the spectral function characterizes initial nucleon states, allowing for factorized cross-section calculations. The research evaluates the effectiveness of the spectral function approach in predicting neutrino-induced reactions and investigates the sensitivity of cross-sections to various components of the
spectral function.
The Monte Carlo method was employed to compute the semi-inclusive cross-section by stochastically sampling the kinematic space of a neutrino-nucleon scattering process. The core of the code is a Monte Carlo loop, which iterates numerous times to simulate scattering events. Within each iteration, it generates random values for specific kinematic variables such as angles and momenta, effectively mimicking the random nature of real-world particle interactions. The acceptance or rejection of these randomly generated events is determined by imposing constraints imposed by the model chosen and experimental conditions.
The calculated cross-sections showed notable agreement with MicroBooNE experimental data, demonstrating the Spectral Function Approach's (SFA) realistic depiction of neutrino-argon quasi-elastic scattering, even without final state interactions. Sensitivity analysis revealed that a pure shell model is inadequate for 40Ar due to its assumption of fully occupied shells. Additionally, cross-sections were sensitive to the spectroscopic factor, suggesting minimal contribution from nuclear correlations, which are prominent at high missing momentum and energy values outside the quasi-elastic scattering regime.
Finally, an analysis of inverse imbalance kinematics underscores the importance of including final state interactions for a more accurate theoretical model. This can be achieved by extending the SFA beyond
PWIA, particularly through the Distorted Wave Spectral Function approach.
