Improved measurement of neutrino oscillation parameters by the NOvA experiment
Improved measurement of neutrino oscillation parameters by the NOvA experiment
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DOI：
10.1103/physrevd.106.032004
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发表时间：
2022-08-03
影响因子：
5
通讯作者：
Zwaska, R.
中科院分区：
文献类型：
--
作者：
Acero, M. A.;Adamson, P.;Zwaska, R.
我们提出了新的nu（mu）-> nu（e），nu（mu）-> nu（mu），（nu）over bar（mu）->（nu）over bar（e），（nu）over bar（mu）->（nu）over bar（mu）振荡测量的NOvA实验，中微子模式束曝光比以前报道的结果增加了50%。额外的数据，结合以前发表的中微子和反中微子数据，都使用改进的技术和模拟进行分析。在3味中微子振荡框架内，对nu（e）、nu（mu）、bar（e）上的（nu）和bar（mu）上的（nu）候选样本的联合拟合继续在正常质量排序和θ（23）混合角的上八分圆中产生最佳拟合点，其中Δ m（32）（2）=（2.41 +/-0.07）× 10（-3）eV（2）和sin（2）θ（23）= 0.57（-0.04）（+0.03）。这些数据不利于振荡参数的组合，这些振荡参数的组合会导致nu（e）和（nu）与棒（e）出现率的大不对称。这包括在delta（CP）= pi/2附近的违反电荷宇称对称性（CP）的相位的值，其对于反向质量排序被> 3 sigma排除，以及在正常排序中delta（CP）= 3 pi/2附近的值，其在2 sigma置信度下是不利的。
We present new nu(mu) -> nu(e), nu(mu) -> nu(mu), (nu) over bar (mu) -> (nu) over bar (e), and (nu) over bar (mu) -> (nu) over bar (mu) oscillation measurements by the NOvA experiment, with a 50% increase in neutrino-mode beam exposure over the previously reported results. The additional data, combined with previously published neutrino and antineutrino data, are all analyzed using improved techniques and simulations. A joint fit to the nu(e), nu(mu), (nu) over bar (e), and (nu) over bar (mu), candidate samples within the 3-flavor neutrino oscillation framework continues to yield a best-fit point in the normal mass ordering and the upper octant of the theta(23) mixing angle, with Delta m(32)(2) = (2.41 +/- 0.07) x 10(-3) eV(2) and sin(2)theta(23) = 0.57(-0.04)(+0.03). The data disfavor combinations of oscillation parameters that give rise to a large asymmetry in the rates of nu(e) and (nu) over bar (e) appearance. This includes values of the charge parity symmetry (CP) violating phase in the vicinity of delta(CP) = pi/2 which arc excluded by > 3 sigma for the inverted mass ordering, and values around delta(CP) = 3 pi/2 in the normal ordering which are disfavored at 2 sigma confidence.