Studying Neutrino Oscillations Using Quasi-Elastic Events in MINOS, (Thesis/Dissertation)

摘要

MINOS (Main Injector Neutrino Oscillation Search), is a long baseline neutrino experiment designed to search for neutrino oscillations using two detectors at Fermi National Accelerator Laboratory, IL (Near Detector) and Soudan, MN (Far Detector). It will study (nu)(sub (mu)) (yields) (nu)(sub (tau)) oscillations and make a measurement on the oscillation parameters, (Delta)m(sub 23)(sup 2) and sin(sup 2) 2(theta)(sub 23), via a (nu)(sub (mu)) beam made at Fermilab. Charge current neutrino interactions in the MINOS detectors are of three types: quasi-elastic scattering (QEL), resonance scattering (RES) and deep inelastic scattering (DIS). Of these, quasi-elastic scattering leaves the cleanest signal with just one (mu) and one proton in the final state, thus rendering the reconstruction of the neutrino energy more accurate. This thesis will outline a method to separate QEL events from the others in the two detectors and perform a calculation of (Delta)m(sub 23)(sup 2) and sin(sup 2) 2(theta)(sub 23) using those events. The period under consideration was May 2005 to February 2006. The number of observed quasi-elastic events with energies below 10 GeV was 29, where the expected number was 60 (+-) 3. A fit to the energy distribution of these events gives (Delta)m(sub 23)(sup 2) = 2.91(sub -0.53)(sup +0.49)(stat)(sub -0.09)(sup +0.08)(sys) x 10(sup -3) eV(sup 2) and sin(sup 2) 2(theta)(sub 23) = 0.990(sub -0.180)(stat)(sub -0.030)(sys).