Details

Autor(en) / Beteiligte

• Barinov, V. V.
• Cleveland, B. T.
• Danshin, S. N.
• Ejiri, H.
• Elliott, S. R.
• Frekers, D.
• Gavrin, V. N.
• Gorbachev, V. V.
• Gorbunov, D. S.
• Haxton, W. C.
• Ibragimova, T. V.
• Kim, I.
• Kozlova, Yu. P.
• Kravchuk, L. V.
• Kuzminov, V. V.
• Lubsandorzhiev, B. K.
• Malyshkin, Yu. M.
• Massarczyk, R.
• Matveev, V. A.
• Mirmov, I. N.
• Nico, J. S.
• Petelin, A. L.
• Robertson, R. G. H.
• Sinclair, D.
• Shikhin, A. A.
• Tarasov, V. A.
• Trubnikov, G. V.
• Veretenkin, E. P.
• Wilkerson, J. F.
• Zvir, A. I.

Titel

Results from the Baksan Experiment on Sterile Transitions (BEST)

Ist Teil von

• Physical review letters, 2022-06, Vol.128 (23), p.232501-232501, Article 232501

Ort / Verlag

United States: American Physical Society (APS)

Erscheinungsjahr

2022

Quelle

American Physical Society

Beschreibungen/Notizen

• The Baksan Experiment on Sterile Transitions (BEST) was designed to investigate the deficit of electron neutrinos νe observed in previous gallium-based radiochemical measurements with high-intensity neutrino sources, commonly referred to as the "gallium anomaly," which could be interpreted as evidence for oscillations between νe and sterile neutrino (νs) states. A 3.414-MCi 51Cr νe source was placed at the center of two nested Ga volumes and measurements were made of the production of 71Ge through the charged current reaction, 71Ga(νe,e-)71Ge, at two average distances. The measured production rates for the inner and the outer targets, respectively, are [54.9$_{-2.4}^{+2.5}$(stat)±1.4(syst)] and [55.6$_{-2.6}^{+2.7}$(stat)±1.4(syst)] atoms of 71Ge/d. The ratio (R) of the measured rate of 71Ge production at each distance to the expected rate from the known cross section and experimental efficiencies are Rin=0.79±0.05 and Rout=0.77±0.05. The ratio of the outer to the inner result is 0.97±0.07, which is consistent with unity within uncertainty. The rates at each distance were found to be similar, but 20%-24% lower than expected, thus reaffirming the anomaly. Therefore these results are consistent with νe→νs oscillations with a relatively large Δm2 (> 0.5 eV2) and mixing sin22θ (≈0.4).