Joint Measurement of the ^{235}U Antineutrino Spectrum by PROSPECT and STEREO

H Almazán; M Andriamirado; A B Balantekin; H R Band; C D Bass; D E Bergeron; L Bernard; A Blanchet; A Bonhomme; N S Bowden; C D Bryan; C Buck; T Classen; A J Conant; G Deichert; P Del Amo Sanchez; A Delgado; M V Diwan; M J Dolinski; I El Atmani; A Erickson; B T Foust; J K Gaison; A Galindo-Uribarri; C E Gilbert; S Hans; A B Hansell; K M Heeger; B Heffron; D E Jaffe; S Jayakumar; X Ji; D C Jones; J Koblanski; O Kyzylova; L Labit; J Lamblin; C E Lane; T J Langford; J LaRosa; A Letourneau; D Lhuillier; M Licciardi; M Lindner; B R Littlejohn; X Lu; J Maricic; T Materna; M P Mendenhall; A M Meyer; R Milincic; P E Mueller; H P Mumm; J Napolitano; R Neilson; J A Nikkel; S Nour; J L Palomino; H Pessard; D A Pushin; X Qian; J-S Réal; J-S Ricol; C Roca; R Rogly; R Rosero; T Salagnac; V Savu; S Schoppmann; M Searles; V Sergeyeva; T Soldner; A Stutz; P T Surukuchi; M A Tyra; R L Varner; D Venegas-Vargas; M Vialat; P B Weatherly; C White; J Wilhelmi; A Woolverton; M Yeh; C Zhang; X Zhang; PROSPECT Collaboration; STEREO Collaboration

doi:10.1103/PhysRevLett.128.081802

Joint Measurement of the ^{235}U Antineutrino Spectrum by PROSPECT and STEREO

Phys Rev Lett. 2022 Feb 25;128(8):081802. doi: 10.1103/PhysRevLett.128.081802.

Authors

H Almazán¹, M Andriamirado², A B Balantekin³, H R Band⁴, C D Bass⁵, D E Bergeron⁶, L Bernard⁷, A Blanchet⁸, A Bonhomme^{1

8}, N S Bowden⁹, C D Bryan¹⁰, C Buck¹, T Classen⁹, A J Conant¹⁰, G Deichert¹⁰, P Del Amo Sanchez¹¹, A Delgado^{12

13}, M V Diwan¹⁴, M J Dolinski¹⁵, I El Atmani⁸, A Erickson¹⁶, B T Foust⁴, J K Gaison⁴, A Galindo-Uribarri^{12

13}, C E Gilbert^{12

13}, S Hans¹⁴, A B Hansell¹⁷, K M Heeger⁴, B Heffron^{12

13}, D E Jaffe¹⁴, S Jayakumar¹⁵, X Ji¹⁴, D C Jones¹⁷, J Koblanski¹⁸, O Kyzylova¹⁵, L Labit¹¹, J Lamblin⁷, C E Lane¹⁵, T J Langford⁴, J LaRosa⁶, A Letourneau⁸, D Lhuillier⁸, M Licciardi⁷, M Lindner¹, B R Littlejohn², X Lu^{12

13}, J Maricic¹⁸, T Materna⁸, M P Mendenhall⁹, A M Meyer¹⁸, R Milincic¹⁸, P E Mueller¹², H P Mumm⁶, J Napolitano¹⁷, R Neilson¹⁵, J A Nikkel⁴, S Nour⁶, J L Palomino², H Pessard¹¹, D A Pushin¹⁹, X Qian¹⁴, J-S Réal⁷, J-S Ricol⁷, C Roca¹, R Rogly⁸, R Rosero¹⁴, T Salagnac⁷, V Savu⁸, S Schoppmann¹, M Searles¹⁰, V Sergeyeva¹¹, T Soldner²⁰, A Stutz⁷, P T Surukuchi⁴, M A Tyra⁶, R L Varner¹², D Venegas-Vargas^{12

13}, M Vialat²⁰, P B Weatherly¹⁵, C White², J Wilhelmi⁴, A Woolverton¹⁹, M Yeh¹⁴, C Zhang¹⁴, X Zhang⁹; PROSPECT Collaboration; STEREO Collaboration

Affiliations

¹ Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
² Department of Physics, Illinois Institute of Technology, Chicago, Illinois, USA.
³ Department of Physics, University of Wisconsin, Madison, Wisconsin, USA.
⁴ Wright Laboratory, Department of Physics, Yale University, New Haven, Connecticut, USA.
⁵ Department of Physics, Le Moyne College, Syracuse, New York, USA.
⁶ National Institute of Standards and Technology, Gaithersburg, Maryland, USA.
⁷ University Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38000 Grenoble, France.
⁸ IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France.
⁹ Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California, USA.
¹⁰ High Flux Isotope Reactor, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.
¹¹ Univ. Savoie Mont Blanc, CNRS, LAPP-IN2P3, 74000 Annecy, France.
¹² Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.
¹³ Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, USA.
¹⁴ Brookhaven National Laboratory, Upton, New York, USA.
¹⁵ Department of Physics, Drexel University, Philadelphia, Pennsylvania, USA.
¹⁶ George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia USA.
¹⁷ Department of Physics, Temple University, Philadelphia, Pennsylvania, USA.
¹⁸ Department of Physics and Astronomy, University of Hawaii, Honolulu, Hawaii, USA.
¹⁹ Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada.
²⁰ Institut Laue-Langevin, CS 20156, 38042 Grenoble Cedex 9, France.

PMID: 35275665
DOI: 10.1103/PhysRevLett.128.081802

Abstract

The PROSPECT and STEREO collaborations present a combined measurement of the pure ^{235}U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with χ^{2}/ndf=24.1/21, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This ν[over ¯]_{e} energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model χ^{2} value is improved, corresponding to a 2.4σ significance.