Browsing by Subject "COHERENT"

The growth in the neutrino sector over the last several decades has offered interesting answers to questions about the neutrino's fundamental nature and the essential role it plays in astrophysical processes. The field's success allows a trend towards bolder and more precise observations of the oft-eluding particle, and concrete cross section measurements are possible like never before. Coherent elastic neutrino-nucleus scattering (CEvNS) is a neutral-current process in which a neutrino scatters off a nucleus as a cohesive unit, depositing a tiny recoil energy (few-to-tens-of-keV). Observed for the first time by the COHERENT experiment in 2017, the clean theoretical cross section prediction allows CEvNS to function as not only a probe for non-standard interactions and nuclear form factors, but also as a predictable flavor-blind signature from all manner of sources. The process is important in core-collapse supernovae and also presents an opportunity for detection of a burst of core-collapse neutrinos in low-threshold detectors designed for solar neutrino and dark matter detection. Often partnered with neutrino beam facilities, a second trend in the field has been leveraging new technologies and techniques to scale up to the ton-scale and beyond.

The work presented here will cover the ability of ton-scale scintillators to measure CEvNS interactions with neutrinos from two sources. The first covers the prospects for flavor-blind supernova neutrino burst detection via CEvNS (E$\nu$=10s of MeV) in existing and future large scintillating detectors. This study will present an analytic method for obtaining the expected photon spectra and provide predictions on the CEvNS observation power during the exceedingly neutrino-luminous burst. The second undertaking details the deployment of COHERENT's new multi-ton NaI[Tl] subsystem, a scintillating detector designed to observe CEvNS from pulsed, stopped-pion neutrinos at the Spallation Neutron Source (also 10s of MeV). Analysis of the in-situ backgrounds of the first half-ton module is conducted to lay the foundation for a long-term CEvNS measurement on sodium.

Neutrinos represent a rich field of physics that contains many theoretical problems that are yet to be solved and experimental results hinting at physics beyond the standard model of particle physics (BSM). An experiment studying neutrino physics and that is the source of the data used in the studies presented here is COHERENT. Its primary goals are to measure and characterize coherent elastic neutrino-nucleus scattering (CEvNS). Studying CEvNS, a standard-model process, provides a direct way to constrain BSM theories. The area of Neutrino Physics that is primarily studied in this work is non-standard neutrino interactions (NSI). I use the data taken by the CsI and CENNS-10 detectors of the COHERENT experiment to improve the constraint on the vector electron-electron

NSI couplings with the up and down quarks. In addition to combining the data of those detectors, I use the Feldman-Cousins technique to improve the NSI limit, obtaining a result that is stronger than prior constraints. Multiple future improvements are discussed.

Another topic investigated here is non-zero neutrino magnetic moments, that, if measured, would point to BSM physics. I estimate the sensitivity of the future COHERENT program to the muon neutrino magnetic moment by minimizing the likelihood function of observing nuclear recoils due to that neutrino magnetic moment in the COHERENT Ge detector. The obtained predicted sensitivity is not as strong as indirect limits, but is similar to existing direct constraints.