| The free neutron beta decay correlation A0 between neutron polarization and electron emission direction provides the strongest constraint on the ratio lambda = gA/g V of the Axial-vector to Vector coupling constants in Weak decay. In conjunction with the CKM Matrix element V ud and the neutron lifetime taun, lambda provides a test of Standard Model assumptions for the Weak interaction. Leading high-precision measurements of A0 and tau n in the 1995--2005 time period showed discrepancies with prior measurements and Standard Model predictions for the relationship between lambda, tau n, and Vud. The UCNA experiment was developed to measure A0 from decay of polarized ultracold neutrons (UCN), providing a complementary determination of lambda with different systematic uncertainties from prior cold neutron beam experiments. This dissertation describes analysis of the dataset collected by UCNA in 2010, with emphasis on detector response calibrations and systematics. The UCNA measurement is placed in the context of the most recent tau n results and cold neutron A0 experiments. |
