Calculation of Atmospheric Neutrino-Induced Backgrounds in a Nucleon-Decay Search

1986 ◽  
Vol 57 (16) ◽  
pp. 1986-1989 ◽  
Author(s):  
T. J. Haines ◽  
R. M. Bionta ◽  
G. Blewitt ◽  
C. B. Bratton ◽  
D. Casper ◽  
...  
2001 ◽  
Vol 16 (supp01b) ◽  
pp. 855-859 ◽  
Author(s):  
◽  
KENNETH S. GANEZER

We have analyzed 1144 days of Super-Kamiokande data for 13 of the more than 40 possible nucleon decay modes. We have studied p→e+π0, and twelve other two particle B-L conserving decay modes including those with kaons that are preferred in supersymmetric theories. Most modes are currently free of candidate events. In all cases the number of candidates is consistent with atmospheric neutrino induced backgrounds. We have calculated 90% confidence level single sided lower limits on the lifetime of the neutron and proton (divided by the unknown branching ratio) for the studied modes. All of our lower limits are higher than previous best limits by a factor of 2-10. Our limit for p→e+π0 is now 4.4×1033 years.


1986 ◽  
Vol 55 (11) ◽  
pp. 3786-3805 ◽  
Author(s):  
Masayuki Nakahata ◽  
Katsushi Arisaka ◽  
Takaaki Kajita ◽  
Masatoshi Koshiba ◽  
Yuichi Oyama ◽  
...  

2003 ◽  
Vol 18 (22) ◽  
pp. 3809-3819
Author(s):  
◽  
C. SAJI

Latest atmospheric neutrino results from 1489 days exposure of the Super-Kamiokande detector are presented. Our data are well explained by two flavor νμ↔ντ oscillations. In the three flavor oscillation case, the result shows no evidence for non zero θ13. Other models, ντ-νs admixture and neutrino decay, are strongly constrained. Moreover, the appearance searches for tau neutrino interactions are performed. Our data are consistent with ντ appearance. For the nucleon decay, p → e+π0 and [Formula: see text] are searched for, but no evidence for nucleon decays has been found. Experimental lower limits for nucleon partial lifetime are obtained to be 5.7×1033 years for p → e+π0 and 2.0×1033 years for [Formula: see text].


2021 ◽  
pp. 136525
Author(s):  
F. Oosterhof ◽  
J. de Vries ◽  
R.G.E. Timmermans ◽  
U. van Kolck
Keyword(s):  

2002 ◽  
Vol 17 (24) ◽  
pp. 3364-3377 ◽  
Author(s):  
◽  
C. K. JUNG

K2K is a long baseline neutrino oscillation experiment using a neutrino beam produced at the KEK 12 GeV PS, a near detector complex at KEK and a far detector (Super-Kamiokande) in Kamioka, Japan. The experiment was constructed and is being operated by an international consortium of institutions from Japan, Korea, and the US. The experiment started taking data in 1999 and has successfully taken data for about two years. K2K is the first long beseline neutrino oscillation experiment with a baseline of order hundreds of km and is the first accelerator based neutrino oscillation experiment that is sensitive to the Super-Kamiokande allowed region obtained from the atmospheric neutrino oscillation analysis. A total of 44 events have been observed in the far detector during the period of June 1999 to April 2001 corresponding to 3.85 × 1019 protons on target. The observation is consistent with the neutrino oscillation expectations based on the oscillation parameters derived from the atmospheric neutrinos, and the probability that this is a statistical fluctuation of non-oscillation expectation of [Formula: see text] is less than 3%.


1998 ◽  
Vol 439 (1-2) ◽  
pp. 123-129 ◽  
Author(s):  
R.P. Thun ◽  
S. McKee
Keyword(s):  

1994 ◽  
Vol 09 (02) ◽  
pp. 169-179 ◽  
Author(s):  
R. FOOT

We re-examine neutrino oscillations in exact parity models. Previously it was shown in a specific model that large neutrino mixing angles result. We show here that this is a general result of neutrino mixing in exact parity models provided that the neutrino mass matrix is real. In this case, the effects of neutrino mixing in exact parity models is such that the probability of a given weak eigenstate remaining in that eigenstate averages to less than half when averaged over many oscillations. This result is interesting in view of the accumulating evidence for a significant deficit in the number of solar neutrinos. It may also be of relevance to the atmospheric neutrino anomaly.


1984 ◽  
Vol 30 (1) ◽  
pp. 80-88 ◽  
Author(s):  
G. V. Dass ◽  
K. V. L. Sarma

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