First Observation of PeV-Energy Neutrinos with IceCube
First Observation of PeV-Energy Neutrinos with IceCube
复制标题
DOI：
10.1103/physrevlett.111.021103
复制
发表时间：
2013-07-08
影响因子：
8.6
通讯作者：
Zoll, M.
中科院分区：
文献类型：
--
作者：
Aartsen, M. G.;Abbasi, R.;Zoll, M.
我们报告的观测两个中微子引起的事件，估计沉积在冰立方探测器的能量分别为1.04 +/- 0.16和1.14 +/- 0.17 PeV，迄今为止观察到的最高中微子能量。这些事件与IceCube探测器内中性电流nu（e，mu，tau）（（nu）over bar（e，mu，tau））或带电电流nu（e）（（nu）over bar（e））相互作用引起的完全包含的粒子簇射一致。这些事件是在使用对应于615.9天有效寿命的数据搜索高能中微子时发现的。大气背景的预期数量为0.082 +/- 0.004（统计）（-0.057）（+0.041）（系统）。考虑到背景事件预期数量的不确定性，在仅大气背景假设下观察到两个或更多候选事件的概率为2.9 x 10（-3）（2.8 sigma）。这两个事件可能是天体物理中微子通量的第一个迹象;然而，适度的意义并不允许在这个时候得出明确的结论。
We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04 +/- 0.16 and 1.14 +/- 0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current nu(e,mu,tau) ((nu) over bar (e,mu,tau)) or charged-current nu(e) ((nu) over bar (e)) interactions within the IceCube detector. The events were discovered in a search for ultrahigh energy neutrinos using data corresponding to 615.9 days effective live time. The expected number of atmospheric background is 0.082 +/- 0.004(stat)(-0.057)(+0.041)(syst). The probability of observing two or more candidate events under the atmospheric background-only hypothesis is 2.9 x 10(-3) (2.8 sigma) taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux; the moderate significance, however, does not permit a definitive conclusion at this time.