Reactor neutrino anomalies
Семинары
Общелабораторный семинар
Дата и время: четверг, 21 июня 2018 г., в 15:00
Место: Конференц-зал им. Блохинцева (4-й этаж), Лаборатория теоретической физики им. Н.Н. Боголюбова
Тема семинара: «Reactor neutrino anomalies»
Докладчик: П. Вогель (Калифорнийский технологический институт, США)
Аннотация:
In the last twenty years several neutrino anomalies were observed. They include experimental results involving disappearance of neutrons of a certain flavor, or appearance of neutrons of a different flavor, which do not fit into the standard three neutrino flavor scenario. Their common characteristic feature is that L/Ev ~ 1m/MeV, perhaps implying existence of additional, sterile, neutrinos with mass of ~ 1eV. I will discuss, in detail, the anomalies involving the nuclear reactor neutrinos. Two of them have been experimentally firmly established: the total rate of the detection reaction ve+p → e++n is about 6% lower than expectation at alll distances from the reactor explored so far, and there is a shoulder (so-called «bump») at ~ 5MeV of the neutrino energy, that is also unexpected. However, these features depend on the assumed reactor ve spectrum. I will describe how the spectrum is evaluated, and discuss its uncertainties. The most recent results, based on the very short baseline experiments, NEOS, 24 m from the reactor core and DANSS, (12.7+10.7) m, are essentially model independent and suggest that △m241 ≈ 1.3 eV2 and sin22θee ≈ 0.04, a ~ 3,5 σ effect. I will discuss how these latest results fit with the previous ones. The story is not over as yet.