Extraction of the U-235 and Pu-239 Antineutrino Spectra at Daya Bay

Adey D.; An F.P.; Balantekin A.B.; Band H.R.; Bishai M.; Blyth S.; Cao D.; Cao G.F.; Cao J.; Chang J.F.; Chang Y.; Chen, H. S.; Chen S.M.; Chen Y.; Chen Y.X.; et. al.

Abstract

This Letter reports the first extraction of individual antineutrino spectra from U-235 and Pu-239 fission and an improved measurement of the prompt energy spectrum of reactor antineutrinos at Daya Bay. The analysis uses 3.5 x 10(6) inverse beta-decay candidates in four near antineutrino detectors in 1958 days. The individual antineutrino spectra of the two dominant isotopes, U-235 and Pu-239, are extracted using the evolution of the prompt spectrum as a function of the isotope fission fractions. In the energy window of 4-6 MeV, a 7% (9%) excess of events is observed for the U-235 (Pu-239) spectrum compared with the normalized Huber-Mueller model prediction. The significance of discrepancy is 4.0 sigma for U-235 spectral shape compared with the Huber-Mueller model prediction. The shape of the measured inverse beta-decay prompt energy spectrum disagrees with the prediction of the Huber-Mueller model at 5.3 sigma. In the energy range of 4-6 MeV, a maximal local discrepancy of 6.3 sigma is observed.

Más información

Título según WOS: Extraction of the U-235 and Pu-239 Antineutrino Spectra at Daya Bay
Título según SCOPUS: Extraction of the U 235 and Pu 239 antineutrino spectra at Daya Bay
Título de la Revista: PHYSICAL REVIEW LETTERS
Volumen: 123
Número: 11
Editorial: AMER PHYSICAL SOC
Fecha de publicación: 2019
Idioma: English
DOI:

10.1103/PhysRevLett.123.111801

Notas: ISI, SCOPUS