اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدNeutrino Oscillation Effects in Soudan-2 Upward-stopping muons
92
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Upward-going stopping muons initiated by atmospheric umu and anumu interactions in the rock below the Soudan 2 detector have been isolated, together with a companion sample of neutrino-induced single muons, created within the detector, which travel downwards and exit. The downward-going sample is consistent with the atmospheric-neutrino flux prediction, but the upward-going sample exhibits a sizeable depletion. Both are consistent with previously reported Soudan-2 neutrino-oscillation results. Inclusion of the two samples in an all-event likelihood analysis, using recent 3D-atmospheric-neutrino-flux calculations, reduces both the allowed oscillation parameter region and the probability of the no-oscillation hypothesis.
قيم البحث
اقرأ أيضاً
An updated measurement of the atmospheric nu_mu/nu_e ratio-of-ratios, 0.68+-0.11+-0.06, has been obtained using a 4.6-kty exposure of the Soudan-2 iron tracking calorimeter. The L/E distributions have been analyzed for effects of nu_mu -> nu_x oscill
ations, and an allowed region in the Delta m^2 vs. sin^2 2 theta plane has been determined.
A new measurement of the atmospheric numu/nue ratio-of-ratios, 0.61 +- 0.15 +- 0.05, has been obtained using a 3.2-kty exposure of the Soudan-2 underground detector. This measurement, based upon neutrino reactions in an iron tracking calorimeter of h
oneycomb-lattice geometry, is in agreement with the anomalously low value reported by the underground water detectors.
The atmospheric neutrino flavour ratio measured using a 1.52 kton-year exposure of Soudan 2 is found to be 0.72 +- 0.19 +0.05 -0.07 relative to the expected value from a Monte Carlo calculation. The possible background of interactions of neutrons and
photons produced in muon interactions in the rock surrounding the detector has been investigated and is shown not to produce low values of the ratio.
We present the results of indirect searches for Weakly Interacting Massive Particles (WIMPs) with 1679.6 live days of data from the Super-Kamiokande detector using neutrino-induced upward through-going muons. The search is performed by looking for an
excess of high energy muon neutrinos from WIMP annihilations in the Sun, the core of the Earth, and the Galactic Center, as compared to the number expected from the atmospheric neutrino background. No statistically significant excess was seen. We calculate flux limits in various angular cones around each of the above celestial objects. We obtain conservative model-independent upper limits on WIMP-nucleon cross-section as a function of WIMP mass and compare these results with the corresponding results from direct dark matter detection experiments.
We report an indication that the elastic scattering rate of solar $^8$B neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through the Earth during nighttime. We determine the day/night asymmetry, defined as t
he difference of the average day rate and average night rate divided by the average of those two rates, to be $(-3.2pm1.1(text{stat})pm0.5(text{syst}))%$, which deviates from zero by 2.7 $sigma$. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a non-zero day/night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos flight path. Super-Kamiokandes day/night asymmetry is consistent with neutrino oscillations for $4times10^{-5}$eV$^2leqDelta m^2_{21}leq7times10^{-5}$eV$^2$ and large mixing values of $theta_{12}$, at the $68%$ C.L.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
