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تسجيل مستخدم جديدDetermination of the Weak Axial Vector Coupling from a Measurement of the Beta-Asymmetry Parameter A in Neutron Beta Decay
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We report on a new measurement of the neutron beta-asymmetry parameter $A$ with the instrument perkeo. Main advancements are the high neutron polarization of $P = 99.7(1)%$ from a novel arrangement of super mirror polarizers and reduced background from improvements in beam line and shielding. Leading corrections were thus reduced by a factor of 4, pushing them below the level of statistical error and resulting in a significant reduction of systematic uncertainty compared to our previous experiments. From the result $A_0 = -0.11996(58)$, we derive the ratio of the axial-vector to the vector coupling constant $lambda = g_mathrm{A}/g_mathrm{V} = -1.2767(16)$
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The neutron $beta$-decay asymmetry parameter $A_0$ defines the correlation between the spin of the neutron and the momentum of the emitted electron, which determines $lambda=frac{g_{A}}{g_{V}}$, the ratio of the axial-vector to vector weak coupling c
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