S. Ajimura, M. Botran, J. H. Choi, J. W. Choi, M. K. Cheoun, T. Dodo, H. Furuta, J. Goh, K. Haga, M. Harada, S. Hasegawa, Y. Hino, T. Hiraiwa, H. I. Jang, J. S.… 展开作者
S. Ajimura, M. Botran, J. H. Choi, J. W. Choi, M. K. Cheoun, T. Dodo, H. Furuta, J. Goh, K. Haga, M. Harada, S. Hasegawa, Y. Hino, T. Hiraiwa, H. I. Jang, J. S. Jang, M. C. Jang, H. Jeon, S. Jeon, K. K. Joo, J. R. Jordan, D. EJung, S. K. Kang, Y. Kasugai, T. Kawasaki, E. J. Kim, J. Y. Kim, S. B. Kim, S. Y. Kim, W. Kim, T. Konno, H. Kinoshita, D. H. Lee, S. Lee, I. T. Lim, E. Marzec, T. Maruyama, S. Masuda, S. Meigo, S. Monjushiro, D. H. Moon, T. Nakano, M. Niiyama, K. Nishikawa, M. Nomachi, M. Y. Pac, J. S. Park, S. J. M. Peeters, H. Ray, G. Roellinghoff, C. Rott, K. Sakai, S. Sakamoto, T. Shima, C. D. Shin, J. Spitz, I. Stancu, Y. Sugaya, F. Suekane, K. Suzuya, M. Taira, R. Ujiie, Y. Yamaguchi, M. Yeh, I. S. Yeo, C. Yoo, I. Yu, A. Zohaib
This article describes the goal and expected sensitivity of the JSNS$^2$-II experiment at J-PARC Materials and Life Science Experimental Facility (MLF). The JSNS$^2$-II experiment is the second phase of the JSNS$^2$ experiment (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) with two detectors which are located in 24 m (an existing detector) and 48 m (new one) baselines to improve the sensitivity of the search for sterile neutrinos, especially in the low $Δm^2$ region, which has been indicated by the global fit of the appearance mode. The new second detector has a similar structure as the existing JSNS$^2$ detector, which is already working. To compensate for the reduction of the neutrino flux due to the distance from the mercury target, the target mass of the Gd-loaded liquid scintillator which is the Linear AlkylBenzene (LAB) based liquid scintillator inside the acrylic vessel is 35 tons. To keep the same photo-coverage of the detector as the first detector, we will surround the acrylic vessel with 240 PMTs. With this experimental setup and 5 years (times 1 MW beam power) exposure, the sensitivity of the JSNS$^2$-II is significantly improved compared to the current JSNS$^2$, especially in the low $Δm^2$ oscillation parameter region. The JSNS$^2$-II can also confirm or refute the most of the oscillation parameters' space preferred by the previous experiments with 3 sigma C.L.. Considering these situations and world wide status of the sterile neutrino searches, we are eager to start the data taking with the two detector configuration from 2023. The fund to build the second detector was already secured.
First results from the search for an excess of $\barν_{e}$ events in JSNS$^2$
High Energy Accelerator Research Organization (KEK)（高能加速器研究机构）；Research Center for Nuclear Physics, Osaka University（大阪大学核物理研究中心）；University of Michigan（密歇根大学）；Department of Physics and OMEG Institute, Soongsil University（崇实大学物理系及OMEG研究所）；Laboratory for High Energy Physics, Dongshin University（东新大学高能物理实验室）；Department of Physics, Chonnam National University（全南国立大学物理系）；Department of Fire Safety, Seoyeong University（西荣大学消防安全系）；Research Center for Neutrino Science, Tohoku University（东北大学中微子科学研究中心）；Advanced Science Research Center, JAEA（日本原子力研究开发机构先进科学研究中心）；J-PARC Center, JAEA（日本原子力研究开发机构J-PARC中心）
