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Search for Proton Decay via p→e+π0 and p→μ+π0 in 0.31 megaton⋅years exposure of the Super-Kamiokande Water Cherenkov Detector
M. Miura (The Super-Kamiokande Collaboration)
(Submitted on 12 Oct 2016)
We have searched for proton decay via p→e+π0 and p→μ+π0 using Super-Kamiokande data from April 1996 to March 2015, 0.306 megaton⋅years exposure in total. The atmospheric neutrino background rate in Super-Kamiokande IV is reduced to almost half that of phase I-III by tagging neutrons associated with neutrino interactions. The reach of the proton lifetime is further enhanced by introducing new signal criteria that select the decay of a proton in a hydrogen atom. No candidates were seen in the p→e+π0 search. Two candidates that passed all of the selection criteria for p→μ+π0 have been observed, but these are consistent with the expected number of background events of 0.87. Lower limits on the proton lifetime are set at τ/B(p→e+π0)>1.6×1034 years and τ/B(p→μ+π0)>7.7×1033 years at 90% confidence level.
Comments: 10 pages, 5 figures
Subjects: High Energy Physics - Experiment (hep-ex)
Cite as: arXiv:1610.03597 [hep-ex]
experiments put proton lifetime past 1.6 10^34 years, which rules out the simplest GUT's SU(5) and SO(10) GUT
what are the implications to unification, including string unification, that the simplest models have been now ruled out?
larger and more complicated GUT seem to imply more particles and forces and seems less parsimonious than just plain SM with no GUT
What are the implications of an idea there is no GUT, only SM but no GUT or GUT-scale, which the results seem to imply?
M. Miura (The Super-Kamiokande Collaboration)
(Submitted on 12 Oct 2016)
We have searched for proton decay via p→e+π0 and p→μ+π0 using Super-Kamiokande data from April 1996 to March 2015, 0.306 megaton⋅years exposure in total. The atmospheric neutrino background rate in Super-Kamiokande IV is reduced to almost half that of phase I-III by tagging neutrons associated with neutrino interactions. The reach of the proton lifetime is further enhanced by introducing new signal criteria that select the decay of a proton in a hydrogen atom. No candidates were seen in the p→e+π0 search. Two candidates that passed all of the selection criteria for p→μ+π0 have been observed, but these are consistent with the expected number of background events of 0.87. Lower limits on the proton lifetime are set at τ/B(p→e+π0)>1.6×1034 years and τ/B(p→μ+π0)>7.7×1033 years at 90% confidence level.
Comments: 10 pages, 5 figures
Subjects: High Energy Physics - Experiment (hep-ex)
Cite as: arXiv:1610.03597 [hep-ex]
experiments put proton lifetime past 1.6 10^34 years, which rules out the simplest GUT's SU(5) and SO(10) GUT
what are the implications to unification, including string unification, that the simplest models have been now ruled out?
larger and more complicated GUT seem to imply more particles and forces and seems less parsimonious than just plain SM with no GUT
What are the implications of an idea there is no GUT, only SM but no GUT or GUT-scale, which the results seem to imply?