А.Г.Ольшевский, ОИЯИ Марковские чтения, 13 мая 2011 «Проект DANSS и проблема потоков реакторных антинейтрино»

План выступления Введение Новые расчеты и аномалия Возможные проверки Проект DANSS Заключение

Осцилляции нейтрино СолнечныеРеакторные Атмосферные Ускорительные

LEP results

HARP

Reactor Data = 0.98 ± 0.03

R=0.86 ± 0.05

Test at Reactors

DANSS detector of the reactor antineutrino To be operated at Kalinin Power Plant ITEP-JINR Collaboration

GEMMA experiment: search for the NMMGEMMA experiment: search for the NMM Since 2005 we do NMM measurements under the unit #2 of the KNPP – a standard 3GW th PWR (ВВЭР-1000)Since 2005 we do NMM measurements under the unit #2 of the KNPP – a standard 3GW th PWR (ВВЭР-1000) Life-time ~ 320 daysLife-time ~ 320 days 1500 kg of 235 U is burned out1500 kg of 235 U is burned out and 311 kg of 239 Pu is producedand 311 kg of 239 Pu is produced which changes the flux and energy spectrum of the neutrino emittedwhich changes the flux and energy spectrum of the neutrino emitted Would like to monitor the neutrino spectrum and flux (2.7∙10 13 /cm 2 /s)Would like to monitor the neutrino spectrum and flux (2.7∙10 13 /cm 2 /s)

Basic element – - scintillator cell (“strip” ) Gd-containing light-reflecting coating Polystyrene- based scintillator 3 wave-length shifting (WLS) fibers Ø1.2 mm

Lifting mechanism 4.1 m

DANSS features Position at short (~10m) distance from the core at industrial power plant (~10000ev/day) High segmentation allows differential calibration to improve energy resolution and event purity Measurement at different distances (change by ~2m)

Искажение спектров и оптимальные расстояния Dm 2 = 0.9 eV 2, sin 2 2q = 0.04 Без учета конечных размеров АЗ 11 м, 16 м, 16/11 Энергия антинейтрино, МэВ 39 В.В. Синев 1, А.С. Старостин 2 1 Институт Ядерных Исследований РАН, 2 Институт Теоретической и Экспериментальной Физики

Conclusions New calculations of the reactor (anti)neutrino fluxes highlighted the problem of the flux deficit Possible explanation of this deficit - the short distance oscillations to sterile neutrino - is also considered to explain LSND, MINIBOONE and Ga Calibration anomalies DANSS experiment which is build by ITEP/JINR collaboration to operate at KPP can contribute to resolve this problem by measuring antineutrino fluxes and spectra at different (short) distances