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46 results on '"Gando Y"'

1. Combined Pre-supernova Alert System with KamLAND and Super-Kamiokande

Author

Abe, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Goto, S, Hachiya, T, Hata, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Mitsui, T, Miyake, H, Morita, D, Nakahata, T, Nakajima, R, Nakamura, K, Nakamura, R, Nakane, J, Ozaki, H, Saito, K, Sakai, T, Shimizu, I, Shirai, J, Shiraishi, K, Shoji, R, Suzuki, A, Takeuchi, A, Tamae, K, Watanabe, H, Watanabe, K, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Fu, Z, Smolsky, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Dell’Oro, S, O’Donnell, T, Detwiler, JA, Enomoto, S, Decowski, MP, Weerman, KM, Grant, C, Song, H, Li, A, Axani, SN, Garcia, M, Collaboration, The KamLAND, Abe, K, Bronner, C, Hayato, Y, Hiraide, K, Hosokawa, K, Ieki, K, Ikeda, M, Kameda, J, Kanemura, Y, Kaneshima, R, Kashiwagi, Y, Kataoka, Y, Miki, S, Mine, S, Miura, M, Moriyama, S, Nakahata, M, Nakano, Y, Nakayama, S, Noguchi, Y, Sato, K, Sekiya, H, Shiba, H, Shimizu, K, Shiozawa, M, Sonoda, Y, Suzuki, Y, Takeda, A, Takemoto, Y, Tanaka, H, Yano, T, and Han, S

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

Preceding a core-collapse supernova (CCSN), various processes produce an increasing amount of neutrinos of all flavors characterized by mounting energies from the interior of massive stars. Among them, the electron antineutrinos are potentially detectable by terrestrial neutrino experiments such as KamLAND and Super-Kamiokande (SK) via inverse beta decay interactions. Once these pre-supernova (pre-SN) neutrinos are observed, an early warning of the upcoming CCSN can be provided. In light of this, KamLAND and SK, both located in the Kamioka mine in Japan, have been monitoring pre-SN neutrinos since 2015 and 2021, respectively. Recently, we performed a joint study between KamLAND and SK on pre-SN neutrino detection. A pre-SN alert system combining the KamLAND detector and the SK detector was developed and put into operation, which can provide a supernova alert to the astrophysics community. Fully leveraging the complementary properties of these two detectors, the combined alert is expected to resolve a pre-SN neutrino signal from a 15 M ⊙ star within 510 pc of the Earth at a significance level corresponding to a false alarm rate of no more than 1 per century. For a Betelgeuse-like model with optimistic parameters, it can provide early warnings up to 12 hr in advance.

Published
2024

2. Search for charged excited states of dark matter with KamLAND-Zen

Author

Abe, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Goto, S, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Mitsui, T, Miyake, H, Morita, D, Nakahata, T, Nakajima, R, Nakamura, K, Nakamura, R, Nakane, J, Ozaki, H, Sakai, T, Shimizu, I, Shirai, J, Shiraishi, K, Shoji, R, Suzuki, A, Takeuchi, A, Tamae, K, Watanabe, H, Watanabe, K, Obara, S, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Ichikawa, A, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Fu, Z, Smolsky, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Dell'Oro, S, O'Donnell, T, Detwiler, JA, Enomoto, S, Decowski, MP, Weerman, KM, Grant, C, Li, A, and Song, H

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Dark matter, Organic liquid scintillator, Xenon, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract

Particle dark matter could belong to a multiplet that includes an electrically charged state. WIMP dark matter (χ0) accompanied by a negatively charged excited state (χ−) with a small mass difference (e.g. < 20 MeV) can form a bound-state with a nucleus such as xenon. This bound-state formation is rare and the released energy is O(1−10) MeV depending on the nucleus, making large liquid scintillator detectors suitable for detection. We searched for bound-state formation events with xenon in two experimental phases of the KamLAND-Zen experiment, a xenon-doped liquid scintillator detector. No statistically significant events were observed. For a benchmark parameter set of WIMP mass mχ0=1 TeV and mass difference Δm=17 MeV, we set the most stringent upper limits on the recombination cross section times velocity 〈σv〉 and the decay-width of χ− to 9.2×10−30 cm3/s and 8.7×10−14 GeV, respectively at 90% confidence level.

Published
2024

3. Measurement of cosmic-ray muon spallation products in a xenon-loaded liquid scintillator with KamLAND

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Fu, Z, Smolsky, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Dell'Oro, S, O'Donnell, T, Detwiler, JA, Enomoto, S, Decowski, MP, Weerman, KM, Grant, C, Li, A, and Song, H

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

Cosmic-ray muons produce various radioisotopes when passing through material. These spallation products can be backgrounds for rare event searches such as in solar neutrino, double-β decay, and dark matter search experiments. The KamLAND-Zen experiment searches for neutrinoless double-β decay in 745 kg of xenon dissolved in liquid scintillator. The experiment includes dead-time-free electronics with a high efficiency for detecting muon-induced neutrons. The production yields of different radioisotopes are measured with a combination of delayed coincidence techniques, newly developed muon reconstruction, and xenon spallation identification methods. The observed xenon spallation products are consistent with results from the fluka and geant4 simulation codes.

Published
2023

4. First measurement of the strange axial coupling constant using neutral-current quasielastic interactions of atmospheric neutrinos at KamLAND

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Fu, Z, Smolsky, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Li, A, Song, H, Dell’Oro, S, and O’Donnell, T

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

We report a measurement of the strange axial coupling constant gAs using atmospheric neutrino data at KamLAND. This constant is a component of the axial form factor of the neutral-current quasielastic (NCQE) interaction. The value of gAs significantly changes the ratio of proton and neutron NCQE cross sections. KamLAND is suitable for measuring NCQE interactions as it can detect nucleon recoils with low-energy thresholds and measure neutron multiplicity with high efficiency. KamLAND data, including the information on neutron multiplicity associated with the NCQE interactions, makes it possible to measure gAs with a suppressed dependence on the axial mass MA, which has not yet been determined. For a comprehensive prediction of the neutron emission associated with neutrino interactions, we establish a simulation of particle emission via nuclear deexcitation of C12, a process not considered in existing neutrino Monte Carlo event generators. Energy spectrum fitting for each neutron multiplicity gives gAs=-0.14-0.26+0.25, which is the most stringent limit obtained using NCQE interactions without MA constraints. The two-body current contribution considered in this analysis relies on a theoretically effective model and electron scattering experiments and requires future verification by direct measurements and future model improvement.

Published
2023

5. Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Maemura, N, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Chernyak, D, Kozlov, A, Nakamura, KZ, Yoshida, S, Takemoto, Y, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Smolsky, J, Fu, Z, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Dell'Oro, S, O'Donnell, T, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Li, A, and Song, H

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, KamLAND-Zen Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>2.3×10^{26}  yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

Published
2023

6. KamLAND’s search for correlated low-energy electron antineutrinos with astrophysical neutrinos from IceCube

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Kurasawa, M, Maemura, N, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Smolsky, J, Lertprasertpong, J, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Song, H, O’Donnell, T, and Dell’Oro, S

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Neutrinos, Astrophysical neutrinos, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Astronomical sciences, Particle and high energy physics
Abstract

We report the results of a search for MeV-scale astrophysical neutrinos in KamLAND presented as an excess in the number of coincident neutrino interactions associated with the publicly available high-energy neutrino datasets from the IceCube Neutrino Observatory. We find no statistically significant excess in the number of observed low-energy electron antineutrinos in KamLAND, given a coincidence time window of ±500 s, ±1,000 s, ±3,600 s, and ±10,000 s around each of the IceCube neutrinos. We use this observation to present limits from 1.8 MeV to 100 MeV on the electron antineutrino fluence, assuming a mono-energetic flux. We then compare the results to several astrophysical measurements performed by IceCube and place a limit at the 90% confidence level on the electron antineutrino isotropic thermal luminosity from the TXS 0506+056 blazar.

Published
2022

7. Abundances of Uranium and Thorium Elements in Earth Estimated by Geoneutrino Spectroscopy

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Maemura, N, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirahata, Y, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Fu, Z, Smolsky, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Song, H, O’Donnell, T, and Dell’Oro, S

Subjects
Affordable and Clean Energy, geoneutrino, radiogenic heat, Earth's interior, mantle composition, Meteorology & Atmospheric Sciences
Abstract

The decay of the primordial isotopes 238U, 235U, 232Th, and 40K has contributed to the terrestrial heat budget throughout the Earth's history. Hence, the individual abundance of those isotopes are key parameters in reconstructing contemporary Earth models. The geoneutrinos produced by the radioactive decays of uranium and thorium have been observed with the Kamioka Liquid-Scintillator Antineutrino Detector (KamLAND). Those measurements have been improved with more than 18-year observation time, and improvement in detector background levels mainly with an 8-year nearly reactor-free period, which now permit spectroscopy with geoneutrinos. Our results yield the first constraint on both uranium and thorium heat contributions. The KamLAND result is consistent with geochemical estimations based on elemental abundances of chondritic meteorites and mantle peridotites. The High-Q model is disfavored at 99.76% C.L. and a fully radiogenic model is excluded at 5.2σ assuming a homogeneous heat producing element distribution in the mantle.

Published
2022

8. Search for Supernova Neutrinos and Constraint on the Galactic Star Formation Rate with the KamLAND Data

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Koga, M, Kurasawa, M, Maemura, N, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, A, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Smolsky, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Song, H, O’Donnell, T, and Dell’Oro, S

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We present the results of a search for core-collapse supernova neutrinos, using long-term KamLAND data from 2002 March 9 to 2020 April 25. We focus on the electron antineutrinos emitted from supernovae in the energy range of 1.8-111 MeV. Supernovae will make a neutrino event cluster with the duration of ∼10 s in the KamLAND data. We find no neutrino clusters and give the upper limit on the supernova rate to be 0.15 yr−1 with a 90% confidence level. The detectable range, which corresponds to a >95% detection probability, is 40-59 kpc and 65-81 kpc for core-collapse supernovae and failed core-collapse supernovae, respectively. This paper proposes to convert the supernova rate obtained by the neutrino observation to the Galactic star formation rate. Assuming a modified Salpeter-type initial mass function, the upper limit on the Galactic star formation rate is

Published
2022

9. Low-energy astrophysics with KamLAND

Author

Kawada, N, Obara, S, Ishidoshiro, K, Grant, C, O’Donnell, T, Dell’Oro, S, Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Kamei, Y, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Ichikawa, AK, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, and Decowski, MP

Abstract

We present two results of a search for MeV-scale neutrino and anti-neutrino events correlated with gravitational wave events/candidates and large solar flares with KamLAND. The KamLAND detector is a large-volume neutrino detector using liquid scintillator, which is located at 1 km underground under the top of Mt. Ikenoyama in Kamioka, Japan. KamLAND has multiple reaction channels to detect neutrinos. Electron antineutrino can be detected via inverse-beta decay with 1.8 MeV neutrino energy threshold. All flavors of neutrinos can be detected via neutrino-electron scattering without neutrino energy threshold. KamLAND has continued the neutrino observation since 2002 March. We use the data set of 60 gravitational waves provided by the LIGO/Virgo collaboration during their second and third observing runs and search for coincident electron antineutrino events in KamLAND. We find no significant coincident signals within a ±500 s timing window from each gravitational wave and present 90% C.L. upper limits on the electron antineutrino fluence between 108–1013 cm−2 for neutrino energies of 1.8–111 MeV. For a solar-flare neutrino search at KamLAND, we determine the timing window using the solar X-ray data set provided by the GOES satellite series from 2002 to 2019 and search for the excess of coincident event rate on the all-flavor neutrinos. We find no significant event rate excess in the flare time windows and get 90% C.L. upper limits on the fluence of neutrinos of all flavors (electron anti-neutrinos) between 1010–1013 cm−2 (108–1013 cm−2) for neutrino energies in the energy range of 0.4–35 MeV.

Published
2022

10. A Search for Correlated Low-energy Electron Antineutrinos in KamLAND with Gamma-Ray Bursts

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Eizuka, M, Kurasawa, M, Nakahata, T, Futagi, S, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Yoshida, S, Umehara, S, Fushimi, K, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Smolsky, J, Laber-Smith, C, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Song, H, O’Donnell, T, and Dell’Oro, S

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We present the results of a time-coincident event search for low-energy electron antineutrinos in the KamLAND detector with gamma-ray bursts (GRBs) from the Gamma-ray Coordinates Network and Fermi Gamma-ray Burst Monitor. Using a variable coincidence time window of ±500 s plus the duration of each GRB, no statistically significant excess above the background is observed. We place the world's most stringent 90% confidence level upper limit on the electron antineutrino fluence below 17.5 MeV. Assuming a Fermi-Dirac neutrino energy spectrum from the GRB source, we use the available redshift data to constrain the electron antineutrino luminosity and effective temperature.

Published
2022

11. KamLAND's search for correlated low-energy electron antineutrinos with astrophysical neutrinos from IceCube

Author

Abe, S, Asami, S, Eizuka, M, Futagi, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Kurasawa, M, Maemura, N, Mitsui, T, Miyake, H, Nakahata, T, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Yoshida, S, Umehara, S, Fushimi, K, Kotera, K, Urano, Y, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Smolsky, J, Lertprasertpong, J, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, Song, H, O'Donnell, T, and Dell'Oro, S

Subjects
astro-ph.HE
Abstract

We report the results of a search for MeV-scale astrophysical neutrinos inKamLAND presented as an excess in the number of coincident neutrinointeractions associated with the publicly available high-energy neutrinodatasets from the IceCube Neutrino Observatory. We find no statisticallysignificant excess in the number of observed low-energy electron antineutrinosin KamLAND, given a coincidence time window of $\pm$500s, $\pm$1,000s,$\pm$3,600s, and $\pm$10,000s around each of the IceCube neutrinos. We use thisobservation to present limits from 1.8 MeV to 100 MeV on the electronantineutrino fluence, assuming a mono-energetic flux. We then compare theresults to several astrophysical measurements performed by IceCube and place alimit at the 90% confidence level on the electron antineutrino isotropicthermal luminosity from the TXS 0506+056 blazar.

Published
2022

12. Limits on Astrophysical Antineutrinos with the KamLAND Experiment

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirahata, Y, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Hirata, S, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, O’Donnell, T, and Dell’Oro, S

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We report on a search for electron antineutrinos ( ) from astrophysical sources in the neutrino energy range 8.3-30.8 MeV with the KamLAND detector. In an exposure of 6.72 kton-year of the liquid scintillator, we observe 18 candidate events via the inverse beta decay reaction. Although there is a large background uncertainty from neutral current atmospheric neutrino interactions, we find no significant excess over background model predictions. Assuming several supernova relic neutrino spectra, we give upper flux limits of 60-110 cm-2 s-1 (90% confidence level, CL) in the analysis range and present a model-independent flux. We also set limits on the annihilation rates for light dark matter pairs to neutrino pairs. These data improve on the upper probability limit of 8B solar neutrinos converting into , (90% CL) assuming an undistorted shape. This corresponds to a solar flux of 60 cm-2 s-1 (90% CL) in the analysis energy range.

Published
2022

13. Search for Solar Flare Neutrinos with the KamLAND Detector

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Ichikawa, AK, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, O’Donnell, T, and Dell’Oro, S

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We report the result of a search for neutrinos in coincidence with solar flares from the GOES flare database. The search was performed on a 10.8 kton-year exposure of KamLAND collected from 2002 to 2019. This large exposure allows us to explore previously unconstrained parameter space for solar flare neutrinos. We found no statistical excess of neutrinos and established 90% confidence level upper limits of 8.4 × 107 cm-2 (3.0 × 109 cm-2) on the electron antineutrino (electron neutrino) fluence at 20 MeV normalized to the X12 flare, assuming that the neutrino fluence is proportional to the X-ray intensity.

Published
2022

14. The nylon balloon for xenon loaded liquid scintillator in KamLAND-Zen 800 neutrinoless double-beta decay search experiment

Author

Gando, Y, Gando, A, Hachiya, T, Hayashida, S, Hosokawa, K, Ikeda, H, Mitsui, T, Nakada, T, Obara, S, Ozaki, H, Shirai, J, Ueshima, K, Watanabe, H, Abe, S, Hata, K, Hayashi, A, Honda, Y, Ieki, S, Inoue, K, Ishidoshiro, K, Ishikawa, S, Kamei, Y, Kamizawa, K, Karino, Y, Kawada, N, Kinoshita, T, Koga, M, Matsuda, S, Miyake, H, Nakamura, K, Nemoto, K, Ono, A, Ota, N, Otsuka, S, Shibukawa, Y, Shimizu, I, Shirahata, Y, Soma, K, Suzuki, A, Suzuki, AA, Takai, T, Takeuchi, A, Tamae, K, Teraoka, Y, Wada, Y, Chernyak, D, Kozlov, A, Yoshida, S, Umehara, S, Takemoto, Y, Fushimi, K, Hirata, S, Grant, C, Li, A, Learned, JG, Maricic, J, Berger, BE, Fujikawa, BK, Fraker, S, Herman, A, Krupczak, E, Pease, GL, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, O'Donnell, T, Dell'Oro, S, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Double-beta decay detectors, Large detector systems for particle and astroparticle physics, Liquid detectors, Physical Sciences, Engineering, Nuclear & Particles Physics
Abstract

The KamLAND-Zen 800 experiment is searching for the neutrinoless double-beta decay of 136Xe by using 136Xe-loaded liquid scintillator. The liquid scintillator is enclosed inside a balloon made of thin, transparent, low-radioactivity film that we call Inner Balloon (IB). The IB, apart from guaranteeing the liquid containment, also allows to minimize the background from cosmogenic muon-spallation products and 8B solar neutrinos. Indeed these events could contribute to the total counts in the region of interest around the Q-value of the double-beta decay of 136Xe. In this paper, we present an overview of the IB and describe the various steps of its commissioning minimizing the radioactive contaminations, from the material selection, to the fabrication of the balloon and its installation inside the KamLAND detector. Finally, we show the impact of the IB on the KamLAND background as measured by the KamLAND detector itself.

Published
2021

15. The nylon balloon for xenon loaded liquid scintillator in KamLAND-Zen 800 neutrinoless double-beta decay search experiment

Author

Gando, Y, Gando, A, Hachiya, T, Hayashida, S, Hosokawa, K, Ikeda, H, Mitsui, T, Nakada, T, Obara, S, Ozaki, H, Shirai, J, Ueshima, K, Watanabe, H, Abe, S, Hata, K, Hayashi, A, Honda, Y, Ieki, S, Inoue, K, Ishidoshiro, K, Ishikawa, S, Kamei, Y, Kamizawa, K, Karino, Y, Kawada, N, Kinoshita, T, Koga, M, Matsuda, S, Miyake, H, Nakamura, K, Nemoto, K, Ono, A, Ota, N, Otsuka, S, Shibukawa, Y, Shimizu, I, Shirahata, Y, Soma, K, Suzuki, A, Suzuki, AA, Takai, T, Takeuchi, A, Tamae, K, Teraoka, Y, Wada, Y, Chernyak, D, Kozlov, A, Yoshida, S, Umehara, S, Takemoto, Y, Fushimi, K, Hirata, S, Grant, C, Li, A, Learned, JG, Maricic, J, Berger, BE, Fujikawa, BK, Fraker, S, Herman, A, Krupczak, E, Pease, GL, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, O'Donnell, T, Dell'oro, S, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Double-beta decay detectors, Large detector systems for particle and astroparticle physics, Liquid detectors, Nuclear & Particles Physics, Physical Sciences, Engineering
Abstract

The KamLAND-Zen 800 experiment is searching for the neutrinoless double-beta decay of 136Xe by using 136Xe-loaded liquid scintillator. The liquid scintillator is enclosed inside a balloon made of thin, transparent, low-radioactivity film that we call Inner Balloon (IB). The IB, apart from guaranteeing the liquid containment, also allows to minimize the background from cosmogenic muon-spallation products and 8B solar neutrinos. Indeed these events could contribute to the total counts in the region of interest around the Q-value of the double-beta decay of 136Xe. In this paper, we present an overview of the IB and describe the various steps of its commissioning minimizing the radioactive contaminations, from the material selection, to the fabrication of the balloon and its installation inside the KamLAND detector. Finally, we show the impact of the IB on the KamLAND background as measured by the KamLAND detector itself.

Published
2021

16. Search for Solar Flare Neutrinos with the KamLAND detector

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Ichikawa, AK, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, O'Donnell, T, and Dell'Oro, S

Subjects
astro-ph.SR, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

We report the result of a search for neutrinos in coincidence with solarflares from the GOES flare database. The search was performed on a 10.8kton-year exposure of KamLAND collected from 2002 to 2019. This large exposureallows us to explore previously unconstrained parameter space for solar flareneutrinos. We found no statistical excess of neutrinos and established 90%confidence level upper limits of $8.4 \times 10^7$ cm$^{-2}$ ($3.0 \times10^{9}$ cm$^{-2}$) on electron anti-neutrino (electron neutrino) fluence at 20MeV normalized to the X12 flare, assuming that the neutrino fluence isproportional to the X-ray intensity.

Published
2021

17. Search for Solar Flare Neutrinos with the KamLAND detector

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Ichikawa, AK, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, O'Donnell, T, and Dell'Oro, S

Subjects
astro-ph.SR
Abstract

We report the result of a search for neutrinos in coincidence with solarflares from the GOES flare database. The search was performed on a 10.8kton-year exposure of KamLAND collected from 2002 to 2019. This large exposureallows us to explore previously unconstrained parameter space for solar flareneutrinos. We found no statistical excess of neutrinos and established 90%confidence level upper limits of $8.4 \times 10^7$ cm$^{-2}$ ($3.0 \times10^{9}$ cm$^{-2}$) on electron anti-neutrino (electron neutrino) fluence at 20MeV normalized to the X12 flare, assuming that the neutrino fluence isproportional to the X-ray intensity.

Published
2021

18. The nylon balloon for xenon loaded liquid scintillator in KamLAND-Zen 800 neutrinoless double-beta decay search experiment

Author

collaboration, KamLAND-Zen, Gando, Y, Gando, A, Hachiya, T, Hayashida, S, Hosokawa, K, Ikeda, H, Mitsui, T, Nakada, T, Obara, S, Ozaki, H, Shirai, J, Ueshima, K, Watanabe, H, Abe, S, Hata, K, Hayashi, A, Honda, Y, Ieki, S, Inoue, K, Ishidoshiro, K, Ishikawa, S, Kamei, Y, Kamizawa, K, Karino, Y, Kawada, N, Kinoshita, T, Koga, M, Matsuda, S, Miyake, H, Nakamura, K, Nemoto, K, Ono, A, Ota, N, Otsuka, S, Shibukawa, Y, Shimizu, I, Shirahata, Y, Soma, K, Suzuki, A, Suzuki, AA, Takai, T, Takeuchi, A, Tamae, K, Teraoka, Y, Wada, Y, Chernyak, D, Kozlov, A, Yoshida, S, Umehara, S, Takemoto, Y, Fushimi, K, Hirata, S, Grant, C, Li, A, Learned, JG, Maricic, J, Berger, BE, Fujikawa, BK, Fraker, S, Herman, A, Krupczak, E, Pease, GL, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, O'Donnell, T, Dell'Oro, S, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
physics.ins-det, hep-ex, nucl-ex
Abstract

The KamLAND-Zen 800 experiment is searching for the neutrinoless double-betadecay of $^{136}$Xe by using $^{136}$Xe-loaded liquid scintillator. The liquidscintillator is enclosed inside a balloon made of thin, transparent,low-radioactivity film that we call Inner Balloon (IB). The IB, apart fromguaranteeing the liquid containment, also allows to minimize the backgroundfrom cosmogenic muon-spallation products and $^{8}$B solar neutrinos. Indeedthese events could contribute to the total counts in the region of interestaround the Q-value of the double-beta decay of $^{136}$Xe. In this paper, wepresent an overview of the IB and describe the various steps of itscommissioning minimizing the radioactive contaminations, from the materialselection, to the fabrication of the balloon and its installation inside theKamLAND detector. Finally, we show the impact of the IB on the KamLANDbackground as measured by the KamLAND detector itself.

Published
2021

19. The nylon balloon for xenon loaded liquid scintillator in KamLAND-Zen 800 neutrinoless double-beta decay search experiment

Author

collaboration, KamLAND-Zen, Gando, Y, Gando, A, Hachiya, T, Hayashida, S, Hosokawa, K, Ikeda, H, Mitsui, T, Nakada, T, Obara, S, Ozaki, H, Shirai, J, Ueshima, K, Watanabe, H, Abe, S, Hata, K, Hayashi, A, Honda, Y, Ieki, S, Inoue, K, Ishidoshiro, K, Ishikawa, S, Kamei, Y, Kamizawa, K, Karino, Y, Kawada, N, Kinoshita, T, Koga, M, Matsuda, S, Miyake, H, Nakamura, K, Nemoto, K, Ono, A, Ota, N, Otsuka, S, Shibukawa, Y, Shimizu, I, Shirahata, Y, Soma, K, Suzuki, A, Suzuki, AA, Takai, T, Takeuchi, A, Tamae, K, Teraoka, Y, Wada, Y, Chernyak, D, Kozlov, A, Yoshida, S, Umehara, S, Takemoto, Y, Fushimi, K, Hirata, S, Grant, C, Li, A, Learned, JG, Maricic, J, Berger, BE, Fujikawa, BK, Fraker, S, Herman, A, Krupczak, E, Pease, GL, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, O'Donnell, T, Dell'Oro, S, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
physics.ins-det, hep-ex, nucl-ex
Abstract

The KamLAND-Zen 800 experiment is searching for the neutrinoless double-betadecay of $^{136}$Xe by using $^{136}$Xe-loaded liquid scintillator. The liquidscintillator is enclosed inside a balloon made of thin, transparent,low-radioactivity film that we call Inner Balloon (IB). The IB, apart fromguaranteeing the liquid containment, also allows to minimize the backgroundfrom cosmogenic muon-spallation products and $^{8}$B solar neutrinos. Indeedthese events could contribute to the total counts in the region of interestaround the Q-value of the double-beta decay of $^{136}$Xe. In this paper, wepresent an overview of the IB and describe the various steps of itscommissioning minimizing the radioactive contaminations, from the materialselection, to the fabrication of the balloon and its installation inside theKamLAND detector. Finally, we show the impact of the IB on the KamLANDbackground as measured by the KamLAND detector itself.

Published
2021

20. Search for Low-energy Electron Antineutrinos in KamLAND Associated with Gravitational Wave Events

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Ichikawa, AK, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, O'Donnell, T, and Dell'Oro, S

Subjects
Neutrino astronomy, Gravitational waves, astro-ph.HE, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry, Astronomy & Astrophysics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural)
Abstract

We present the results of a search for MeV-scale electron antineutrino events in KamLAND coincident with the 60 gravitational wave events/candidates reported by the LIGO/Virgo collaboration during their second and third observing runs. We find no significant coincident signals within a 500 s timing window from each gravitational wave and present 90% C.L. upper limits on the electron antineutrino fluence between 108 and 1013 cm-2 for neutrino energies in the energy range of 1.8-111 MeV.

Published
2021

21. Search for Low-energy Electron Antineutrinos in KamLAND Associated with Gravitational Wave Events

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kishimoto, Y, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Kozlov, A, Chernyak, D, Takemoto, Y, Yoshida, S, Umehara, S, Fushimi, K, Ichikawa, AK, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Axani, SN, Winslow, LA, Fu, Z, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Li, A, Detwiler, JA, Enomoto, S, Decowski, MP, Grant, C, O’Donnell, T, and Dell’Oro, S

Subjects
Neutrino astronomy, Gravitational waves, astro-ph.HE, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We present the results of a search for MeV-scale electron antineutrino events in KamLAND coincident with the 60 gravitational wave events/candidates reported by the LIGO/Virgo collaboration during their second and third observing runs. We find no significant coincident signals within a 500 s timing window from each gravitational wave and present 90% C.L. upper limits on the electron antineutrino fluence between 108 and 1013 cm-2 for neutrino energies in the energy range of 1.8-111 MeV.

Published
2021

22. A Search for Charged Excitation of Dark Matter with the KamLAND-Zen Detector

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ono, A, Ota, N, Otsuka, S, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirahata, Y, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Chernyak, D, Kozlov, A, Yoshida, S, Umehara, S, Takemoto, Y, Fushimi, K, Hirata, S, Ichikawa, A, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Grant, C, Li, A, Learned, JG, Maricic, J, Axani, S, Winslow, LA, Fu, Z, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, ODonnell, T, DellOro, S, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
hep-ex
Abstract

There are many theories where a dark matter particle is part of a multipletwith an electrically charged state. If WIMP dark matter ($\chi^{0}$) isaccompanied by a charged excited state ($\chi^{-}$) separated by a small massdifference, it can form a stable bound state with a nucleus. In supersymmetricmodels, the $\chi^{0}$ and the $\chi^{-}$ could be the neutralino and a chargedslepton, such as the neutralino-stau degenerate model. The formation bindingprocess is expected to result in an energy deposition of {\it O}(1--10 MeV),making it suitable for detection in large liquid scintillator detectors. Wedescribe new constraints on the bound state formation with a xenon nucleususing the KamLAND-Zen 400 Phase-II dataset. In order to enlarge the searchableparameter space, all xenon isotopes in the detector were used. For a benchmarkparameter set of $m_{\chi^{0}} = 100$ GeV and $\Delta m = 10$ MeV, this studysets the most stringent upper limits on the recombination cross section$\langle\sigma v\rangle$ and the decay-width of $\chi^{-}$ of $2.0 \times10^{-31}$ ${\rm cm^3/s}$ and $1.1 \times 10^{-18}$ GeV, respectively (90\%confidence level).

Published
2021

23. A Search for Charged Excitation of Dark Matter with the KamLAND-Zen Detector

Author

Abe, S, Asami, S, Gando, A, Gando, Y, Gima, T, Goto, A, Hachiya, T, Hata, K, Hayashida, S, Hosokawa, K, Ichimura, K, Ieki, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kawada, N, Kinoshita, T, Koga, M, Maemura, N, Mitsui, T, Miyake, H, Nakamura, K, Nakamura, R, Ono, A, Ota, N, Otsuka, S, Ozaki, H, Sakai, T, Sambonsugi, H, Shimizu, I, Shirahata, Y, Shirai, J, Shiraishi, K, Suzuki, A, Suzuki, Y, Takeuchi, A, Tamae, K, Ueshima, K, Wada, Y, Watanabe, H, Yoshida, Y, Obara, S, Chernyak, D, Kozlov, A, Yoshida, S, Umehara, S, Takemoto, Y, Fushimi, K, Hirata, S, Ichikawa, A, Nakamura, KZ, Yoshida, M, Berger, BE, Fujikawa, BK, Grant, C, Li, A, Learned, JG, Maricic, J, Axani, S, Winslow, LA, Fu, Z, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, ODonnell, T, DellOro, S, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
hep-ex
Abstract

There are many theories where a dark matter particle is part of a multipletwith an electrically charged state. If WIMP dark matter ($\chi^{0}$) isaccompanied by a charged excited state ($\chi^{-}$) separated by a small massdifference, it can form a stable bound state with a nucleus. In supersymmetricmodels, the $\chi^{0}$ and the $\chi^{-}$ could be the neutralino and a chargedslepton, such as the neutralino-stau degenerate model. The formation bindingprocess is expected to result in an energy deposition of {\it O}(1--10 MeV),making it suitable for detection in large liquid scintillator detectors. Wedescribe new constraints on the bound state formation with a xenon nucleususing the KamLAND-Zen 400 Phase-II dataset. In order to enlarge the searchableparameter space, all xenon isotopes in the detector were used. For a benchmarkparameter set of $m_{\chi^{0}} = 100$ GeV and $\Delta m = 10$ MeV, this studysets the most stringent upper limits on the recombination cross section$\langle\sigma v\rangle$ and the decay-width of $\chi^{-}$ of $2.0 \times10^{-31}$ ${\rm cm^3/s}$ and $1.1 \times 10^{-18}$ GeV, respectively (90\%confidence level).

Published
2021

24. Precision Analysis of the Xe136 Two-Neutrino ββ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements

Author

Gando, A, Gando, Y, Hachiya, T, Minh, M Ha, Hayashida, S, Honda, Y, Hosokawa, K, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kamizawa, K, Kinoshita, T, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Ono, A, Ota, N, Otsuka, S, Ozaki, H, Shibukawa, Y, Shimizu, I, Shirahata, Y, Shirai, J, Sato, T, Soma, K, Suzuki, A, Takeuchi, A, Tamae, K, Ueshima, K, Watanabe, H, Chernyak, D, Kozlov, A, Obara, S, Yoshida, S, Takemoto, Y, Umehara, S, Fushimi, K, Hirata, S, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, O’Donnell, T, Detwiler, JA, Enomoto, S, Decowski, MP, Menéndez, J, Dvornický, R, and Šimkovic, F

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, KamLAND-Zen Collaboration, hep-ex, nucl-ex, nucl-th, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We present a precision analysis of the ^{136}Xe two-neutrino ββ electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ββ rate allows us to measure the ratio of the leading and subleading 2νββ nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ββ decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ββ NMEs.

Published
2019

25. Precision Analysis of the ^{136}Xe Two-Neutrino ββ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements.

Author

Gando, A, Gando, Y, Hachiya, T, Ha Minh, M, Hayashida, S, Honda, Y, Hosokawa, K, Ikeda, H, Inoue, K, Ishidoshiro, K, Kamei, Y, Kamizawa, K, Kinoshita, T, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Ono, A, Ota, N, Otsuka, S, Ozaki, H, Shibukawa, Y, Shimizu, I, Shirahata, Y, Shirai, J, Sato, T, Soma, K, Suzuki, A, Takeuchi, A, Tamae, K, Ueshima, K, Watanabe, H, Chernyak, D, Kozlov, A, Obara, S, Yoshida, S, Takemoto, Y, Umehara, S, Fushimi, K, Hirata, S, Berger, BE, Fujikawa, BK, Learned, JG, Maricic, J, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, O'Donnell, T, Detwiler, JA, Enomoto, S, Decowski, MP, Menéndez, J, Dvornický, R, Šimkovic, F, and KamLAND-Zen Collaboration

Subjects
KamLAND-Zen Collaboration, hep-ex, nucl-ex, nucl-th, General Physics, Physical Sciences
Abstract

We present a precision analysis of the ^{136}Xe two-neutrino ββ electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ββ rate allows us to measure the ratio of the leading and subleading 2νββ nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ββ decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ββ NMEs.

Published
2019

26. Erratum: “A Search for Electron Antineutrinos Associated with Gravitational-wave Events GW150914 and GW151226 Using KamLAND” (2016, ApJL, 829, L34)

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Piepke, A, Banks, TI, Berger, BE, Fujikawa, BK, O’Donnell, T, Learned, JG, Maricic, J, Sakai, M, Winslow, LA, Krupczak, E, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Space sciences
Published
2017

27. A Search for Electron Antineutrinos Associated with Gravitational-wave Events GW150914 and GW151226 Using KamLAND (vol 829, L34, 2016)

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Piepke, A, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Learned, JG, Maricic, J, Sakai, M, Winslow, LA, Krupczak, E, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, Decowski, MP, and Collaboration, KamLAND

Subjects
Astronomy & Astrophysics, Astronomical and Space Sciences
Published
2017

28. A SEARCH FOR ELECTRON ANTINEUTRINOS ASSOCIATED WITH GRAVITATIONAL-WAVE EVENTS GW150914 AND GW151226 USING KAMLAND

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Piepke, A, Banks, TI, Berger, BE, Fujikawa, BK, O’Donnell, T, Learned, JG, Maricic, J, Sakai, M, Winslow, LA, Krupczak, E, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
gravitational waves, neutrinos, astro-ph.HE, hep-ex, nucl-ex, Astronomical and Space Sciences, Astronomy & Astrophysics
Abstract

We present a search, using KamLAND, a kiloton-scale anti-neutrino detector, for low-energy anti-neutrino events that were coincident with the gravitational-wave (GW) events GW150914 and GW151226, and the candidate event LVT151012. We find no inverse beta-decay neutrino events within ±500 s of either GW signal. This non-detection is used to constrain the electron anti-neutrino fluence and the total integrated luminosity of the astrophysical sources.

Published
2016

29. A SEARCH for ELECTRON ANTINEUTRINOS ASSOCIATED with GRAVITATIONAL-WAVE EVENTS GW150914 and GW151226 USING KAMLAND

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Piepke, A, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Learned, JG, Maricic, J, Sakai, M, Winslow, LA, Krupczak, E, Ouellet, J, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
gravitational waves, neutrinos, astro-ph.HE, hep-ex, nucl-ex, Astronomy & Astrophysics, Astronomical and Space Sciences
Abstract

We present a search, using KamLAND, a kiloton-scale anti-neutrino detector, for low-energy anti-neutrino events that were coincident with the gravitational-wave (GW) events GW150914 and GW151226, and the candidate event LVT151012. We find no inverse beta-decay neutrino events within ±500 s of either GW signal. This non-detection is used to constrain the electron anti-neutrino fluence and the total integrated luminosity of the astrophysical sources.

Published
2016

30. Publisher’s Note: Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen [Phys. Rev. Lett. 117, 082503 (2016)]

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Particle and High Energy Physics, Physical Sciences, KamLAND-Zen Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

This corrects the article DOI: 10.1103/PhysRevLett.117.082503.

Published
2016

31. Publisher's Note: Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen [Phys. Rev. Lett. 117, 082503 (2016)].

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, Decowski, MP, and KamLAND-Zen Collaboration

Subjects
KamLAND-Zen Collaboration, General Physics, Physical Sciences
Abstract

This corrects the article DOI: 10.1103/PhysRevLett.117.082503.

Published
2016

32. Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, KamLAND-Zen Collaboration, hep-ex, nucl-ex, physics.ins-det, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26}  yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

Published
2016

33. Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen.

Author

Gando, A, Gando, Y, Hachiya, T, Hayashi, A, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Karino, Y, Koga, M, Matsuda, S, Mitsui, T, Nakamura, K, Obara, S, Oura, T, Ozaki, H, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Takai, T, Tamae, K, Teraoka, Y, Ueshima, K, Watanabe, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, Decowski, MP, and KamLAND-Zen Collaboration

Subjects
KamLAND-Zen Collaboration, hep-ex, nucl-ex, physics.ins-det, General Physics, Physical Sciences
Abstract

We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26}  yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

Published
2016

34. KamLAND SENSITIVITY TO NEUTRINOS FROM PRE-SUPERNOVA STARS

Author

Asakura, K, Gando, A, Gando, Y, Hachiya, T, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, T, Ishio, S, Koga, M, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Obara, S, Oura, T, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Tachibana, H, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Piepke, A, Banks, TI, Berger, BE, Fujikawa, BK, O’Donnell, T, Learned, JG, Maricic, J, Matsuno, S, Sakai, M, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
neutrinos, supernovae: general, astro-ph.HE, hep-ex, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

In the late stages of nuclear burning for massive stars (M > 8 Mȯ), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 Mȯ at a distance less than 690 pc with 3σ significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.

Published
2016

35. KamLAND SENSITIVITY TO NEUTRINOS FROM PRE-SUPERNOVA STARS

Author

The KamLAND Collaboration, Asakura, K, Gando, A, Gando, Y, Hachiya, T, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, T, Ishio, S, Koga, M, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Obara, S, Oura, T, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Tachibana, H, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Piepke, A, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Learned, JG, Maricic, J, Matsuno, S, Sakai, M, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
neutrinos, supernovae: general, astro-ph.HE, hep-ex, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

In the late stages of nuclear burning for massive stars (M > 8 Mȯ), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 Mȯ at a distance less than 690 pc with 3σ significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.

Published
2016

36. Search for double-beta decay of 136Xe to excited states of 136Ba with the KamLAND-Zen experiment

Author

Asakura, K, Gando, A, Gando, Y, Hachiya, T, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, T, Ishio, S, Koga, M, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Obara, S, Otani, M, Oura, T, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Tachibana, H, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yoshida, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Clinical Research, Double-beta decay, Xe-136, Excited state, hep-ex, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Nuclear and plasma physics, Particle and high energy physics
Abstract

A search for double-beta decays of 136Xe to excited states of 136Ba has been performed with the first phase data set of the KamLAND-Zen experiment. The 01+, 21+ and 22+ transitions of 0νββ decay were evaluated in an exposure of 89.5 kg⋅yr of 136Xe, while the same transitions of 2νββ decay were evaluated in an exposure of 61.8 kg⋅yr. No excess over background was found for all decay modes. The lower half-life limits of the 21+ state transitions of 0νββ and 2νββ decay were improved to T1/20ν(0+→21+)>2.6×1025 yr and T1/22ν(0+→21+)>4.6×1023 yr (90% C.L.), respectively. We report on the first experimental lower half-life limits for the transitions to the 01+ state of 136Xe for 0νββ and 2νββ decay. They are T1/20ν(0+→01+)>2.4×1025 yr and T1/22ν(0+→01+)>8.3×1023 yr (90% C.L.). The transitions to the 22+ states are also evaluated for the first time to be T1/20ν(0+→22+)>2.6×1025 yr and T1/22ν(0+→22+)>9.0×1023 yr (90% C.L.). These results are compared to recent theoretical predictions.

Published
2016

37. Search for double-beta decay of 136Xe to excited states of 136Ba with the KamLAND-Zen experiment

Author

Asakura, K., Gando, A., Gando, Y., Hachiya, T., Hayashida, S., Ikeda, H., Inoue, K., Ishidoshiro, K., Ishikawa, T., Ishio, S., Koga, M., Matsuda, S., Mitsui, T., Motoki, D., Nakamura, K., Obara, S., Otani, M., Oura, T., Shimizu, I., Shirahata, Y., Shirai, J., Suzuki, A., Tachibana, H., Tamae, K., Ueshima, K., Watanabe, H., Xu, B.D., Yoshida, H., Kozlov, A., Takemoto, Y., Yoshida, S., Fushimi, K., Banks, T.I., Berger, B.E., Fujikawa, B.K., O'Donnell, T., Winslow, L.A., Efremenko, Y., Karwowski, H.J., Markoff, D.M., Tornow, W., Detwiler, J.A., Enomoto, S., and Decowski, M.P.

Published
2016

38. Search for double-beta decay of 136Xe to excited states of 136Ba with the KamLAND-Zen experiment

Author

Asakura, K, Gando, A, Gando, Y, Hachiya, T, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, T, Ishio, S, Koga, M, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Obara, S, Otani, M, Oura, T, Shimizu, I, Shirahata, Y, Shirai, J, Suzuki, A, Tachibana, H, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yoshida, H, Kozlov, A, Takemoto, Y, Yoshida, S, Fushimi, K, Banks, TI, Berger, BE, Fujikawa, BK, O'Donnell, T, Winslow, LA, Efremenko, Y, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, and Decowski, MP

Subjects
Double-beta decay, Xe-136, Excited state, hep-ex, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

A search for double-beta decays of 136Xe to excited states of 136Ba has been performed with the first phase data set of the KamLAND-Zen experiment. The 01+, 21+ and 22+ transitions of 0νββ decay were evaluated in an exposure of 89.5 kg⋅yr of 136Xe, while the same transitions of 2νββ decay were evaluated in an exposure of 61.8 kg⋅yr. No excess over background was found for all decay modes. The lower half-life limits of the 21+ state transitions of 0νββ and 2νββ decay were improved to T1/20ν(0+→21+)>2.6×1025 yr and T1/22ν(0+→21+)>4.6×1023 yr (90% C.L.), respectively. We report on the first experimental lower half-life limits for the transitions to the 01+ state of 136Xe for 0νββ and 2νββ decay. They are T1/20ν(0+→01+)>2.4×1025 yr and T1/22ν(0+→01+)>8.3×1023 yr (90% C.L.). The transitions to the 22+ states are also evaluated for the first time to be T1/20ν(0+→22+)>2.6×1025 yr and T1/22ν(0+→22+)>9.0×1023 yr (90% C.L.). These results are compared to recent theoretical predictions.

Published
2016

39. solar neutrino measurement with KamLAND

Author

Gando, A., Gando, Y., Hanakago, H., Ikeda, H., Inoue, K., Ishidoshiro, K., Ishikawa, H., Kishimoto, Y., Koga, M., Matsuda, R., Matsuda, S., Mitsui, T., Motoki, D., Nakajima, K., Nakamura, K., Obata, A., Oki, A., Oki, Y., Otani, M., Shimizu, I., Shirai, J., Suzuki, A., Tamae, K., Ueshima, K., Watanabe, H., Xu, B. D., Yamada, S., Yamauchi, Y., Yoshida, H., Kozlov, A., Takemoto, Y., Yoshida, S., Grant, C., Keefer, G., McKee, D. W., Piepke, A., Banks, T. I., Bloxham, T., Freedman, S. J., Fujikawa, B. K., Han, K., Hsu, L., Ichimura, K., Murayama, H., O'Donnell, T., Steiner, H. M., Winslow, L. A., Dwyer, D., Mauger, C., McKeown, R. D., Zhang, C., Berger, B. E., Lane, C. E., Maricic, J., Miletic, T., Learned, J. G., Sakai, M., Horton-Smith, G. A., Tang, A., Downum, K. E., Tolich, K., Efremenko, Y., Kamyshkov, Y., Perevozchikov, O., Karwowski, H. J., Markoff, D. M., Tornow, W., Detwiler, J. A., Enomoto, S., Heeger, K., and Decowski, M. P.

Published
2015

40. Be 7 solar neutrino measurement with KamLAND

Author

Gando, A, Gando, Y, Hanakago, H, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, H, Kishimoto, Y, Koga, M, Matsuda, R, Matsuda, S, Mitsui, T, Motoki, D, Nakajima, K, Nakamura, K, Obata, A, Oki, A, Oki, Y, Otani, M, Shimizu, I, Shirai, J, Suzuki, A, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yamada, S, Yamauchi, Y, Yoshida, H, Kozlov, A, Takemoto, Y, Yoshida, S, Grant, C, Keefer, G, McKee, DW, Piepke, A, Banks, TI, Bloxham, T, Freedman, SJ, Fujikawa, BK, Han, K, Hsu, L, Ichimura, K, Murayama, H, O'Donnell, T, Steiner, HM, Winslow, LA, Dwyer, D, Mauger, C, McKeown, RD, Zhang, C, Berger, BE, Lane, CE, Maricic, J, Miletic, T, Learned, JG, Sakai, M, Horton-Smith, GA, Tang, A, Downum, KE, Tolich, K, Efremenko, Y, Kamyshkov, Y, Perevozchikov, O, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, Heeger, K, and Decowski, MP

Subjects
hep-ex, astro-ph.SR, nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We report a measurement of the neutrino-electron elastic scattering rate of 862 keV Be7 solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582±94(kt d)-1, which corresponds to an 862-keV Be7 solar neutrino flux of (3.26±0.52)×109cm-2s-1, assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total Be7 solar neutrino flux of (5.82±1.02)×109cm-2s-1, which is consistent with the standard solar model predictions.

Published
2015

41. Be7 solar neutrino measurement with KamLAND

Author

Gando, A, Gando, Y, Hanakago, H, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, H, Kishimoto, Y, Koga, M, Matsuda, R, Matsuda, S, Mitsui, T, Motoki, D, Nakajima, K, Nakamura, K, Obata, A, Oki, A, Oki, Y, Otani, M, Shimizu, I, Shirai, J, Suzuki, A, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yamada, S, Yamauchi, Y, Yoshida, H, Kozlov, A, Takemoto, Y, Yoshida, S, Grant, C, Keefer, G, McKee, DW, Piepke, A, Banks, TI, Bloxham, T, Freedman, SJ, Fujikawa, BK, Han, K, Hsu, L, Ichimura, K, Murayama, H, O'Donnell, T, Steiner, HM, Winslow, LA, Dwyer, D, Mauger, C, McKeown, RD, Zhang, C, Berger, BE, Lane, CE, Maricic, J, Miletic, T, Learned, JG, Sakai, M, Horton-Smith, GA, Tang, A, Downum, KE, Tolich, K, Efremenko, Y, Kamyshkov, Y, Perevozchikov, O, Karwowski, HJ, Markoff, DM, Tornow, W, Detwiler, JA, Enomoto, S, Heeger, K, and Decowski, MP

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, astro-ph.SR, nucl-ex, Nuclear and plasma physics
Abstract

We report a measurement of the neutrino-electron elastic scattering rate of 862 keV Be7 solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582±94(kt d)-1, which corresponds to an 862-keV Be7 solar neutrino flux of (3.26±0.52)×109cm-2s-1, assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total Be7 solar neutrino flux of (5.82±1.02)×109cm-2s-1, which is consistent with the standard solar model predictions.

Published
2015

42. Search for the proton decay mode with KamLAND

Author

Asakura, K., Gando, A., Gando, Y., Hachiya, T., Hayashida, S., Ikeda, H., Inoue, K., Ishidoshiro, K., Ishikawa, T., Ishio, S., Koga, M., Matsuda, R., Matsuda, S., Mitsui, T., Motoki, D., Nakamura, K., Obara, S., Oki, Y., Oura, T., Shimizu, I., Shirahata, Y., Shirai, J., Suzuki, A., Tachibana, H., Tamae, K., Ueshima, K., Watanabe, H., Xu, B. D., Yamauchi, Y., Yoshida, H., Kozlov, A., Takemoto, Y., Yoshida, S., Fushimi, K., Grant, C., Piepke, A., Banks, T. I., Berger, B. E., Freedman, S. J., Fujikawa, B. K., O’Donnell, T., Learned, J. G., Maricic, J., Sakai, M., Dazeley, S., Svoboda, R., Winslow, L. A., Efremenko, Y., Karwowski, H. J., Markoff, D. M., Tornow, W., Detwiler, J. A., Enomoto, S., and Decowski, M. P.

Published
2015

43. CeLAND: search for a 4th light neutrino state with a 3 PBq 144Ce-144Pr electron antineutrino generator in KamLAND

Author

Gando, A, Gando, Y, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, H, Koga, M, Matsuda, R, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Oki, Y, Otani, M, Shimizu, I, Shirai, J, Suekane, F, Suzuki, A, Takemoto, Y, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yamada, S, Yamauchi, Y, Yoshida, H, Cribier, M, Durero, M, Fischer, V, Gaffiot, J, Jonqueres, N, Kouchner, A, Lasserre, T, Leterme, D, Letourneau, A, Lhuillier, D, Mention, G, Rampal, G, Scola, L, Veyssiere, Ch, Vivier, M, Yala, P, Berger, BE, Kozlov, A, Banks, T, Dwyer, D, Fujikawa, BK, Han, K, Kolomensky, Yu G, Mei, Y, O'Donnell, T, Decowski, P, Markoff, DM, Yoshida, S, Kornoukhov, VN, Gelis, TVM, Tikhomirov, GV, Learned, JG, Maricic, J, Matsuno, S, Milincic, R, Karwowski, HJ, Efremenko, Y, Detwiler, A, and Enomoto, S

Subjects
physics.ins-det, hep-ex
Abstract

The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq(75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the centeror next to a large low-background liquid scintillator detector. Theantineutrino generator will be produced by the Russian reprocessing plant PAMayak as early as 2014, transported to Japan, and deployed in the KamiokaLiquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015.KamLAND's 13 m diameter target volume provides a suitable environment tomeasure the energy and position dependence of the detected neutrino flux. Acharacteristic oscillation pattern would be visible for a baseline of about 10m or less, providing a very clean signal of neutrino disappearance into ayet-unknown, sterile neutrino state. This will provide a comprehensive test ofthe electron dissaperance neutrino anomalies and could lead to the discovery ofa 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.

Published
2013

44. CeLAND: search for a 4th light neutrino state with a 3 PBq 144Ce-144Pr electron antineutrino generator in KamLAND

Author

Gando, A, Gando, Y, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, H, Koga, M, Matsuda, R, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Oki, Y, Otani, M, Shimizu, I, Shirai, J, Suekane, F, Suzuki, A, Takemoto, Y, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yamada, S, Yamauchi, Y, Yoshida, H, Cribier, M, Durero, M, Fischer, V, Gaffiot, J, Jonqueres, N, Kouchner, A, Lasserre, T, Leterme, D, Letourneau, A, Lhuillier, D, Mention, G, Rampal, G, Scola, L, Veyssiere, Ch, Vivier, M, Yala, P, Berger, BE, Kozlov, A, Banks, T, Dwyer, D, Fujikawa, BK, Han, K, Kolomensky, Yu G, Mei, Y, O'Donnell, T, Decowski, P, Markoff, DM, Yoshida, S, Kornoukhov, VN, Gelis, TVM, Tikhomirov, GV, Learned, JG, Maricic, J, Matsuno, S, Milincic, R, Karwowski, HJ, Efremenko, Y, Detwiler, A, and Enomoto, S

Subjects
physics.ins-det, hep-ex
Abstract

The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq(75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the centeror next to a large low-background liquid scintillator detector. Theantineutrino generator will be produced by the Russian reprocessing plant PAMayak as early as 2014, transported to Japan, and deployed in the KamiokaLiquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015.KamLAND's 13 m diameter target volume provides a suitable environment tomeasure the energy and position dependence of the detected neutrino flux. Acharacteristic oscillation pattern would be visible for a baseline of about 10m or less, providing a very clean signal of neutrino disappearance into ayet-unknown, sterile neutrino state. This will provide a comprehensive test ofthe electron dissaperance neutrino anomalies and could lead to the discovery ofa 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.

Published
2013

45. White paper: CeLAND - Investigation of the reactor antineutrino anomaly with an intense 144Ce-144Pr antineutrino source in KamLAND

Author

Gando, A, Gando, Y, Hayashida, S, Ikeda, H, Inoue, K, Ishidoshiro, K, Ishikawa, H, Koga, M, Matsuda, R, Matsuda, S, Mitsui, T, Motoki, D, Nakamura, K, Oki, Y, Otani, M, Shimizu, I, Shirai, J, Suekane, F, Suzuki, A, Takemoto, Y, Tamae, K, Ueshima, K, Watanabe, H, Xu, BD, Yamada, S, Yamauchi, Y, Yoshida, H, Banks, T, Berger, BE, Cribier, M, Decowski, P, Detwiler, JA, Durero, M, Dwyer, D, Efremenko, Y, Enomoto, S, Fischer, V, Fujikawa, BK, Gaffiot, J, Gelis, VM, Karwowski, HJ, Kolomensky, Yu G, Kozlov, A, Kornoukhov, VN, Lasserre, T, Learned, JG, Letourneau, A, Lhuillier, D, Maricic, J, Markoff, DM, Matsuno, S, Mention, G, Milincic, R, ODonnell, T, Saldikov, IS, Scola, L, Tikhomirov, GV, Veyssiere, Ch, Vivier, M, and Yoshida, S

Subjects
hep-ex
Abstract

We propose to test for short baseline neutrino oscillations, implied by therecent reevaluation of the reactor antineutrino flux and by anomalous resultsfrom the gallium solar neutrino detectors. The test will consist of producing a75 kCi 144Ce - 144Pr antineutrino source to be deployed in the Kamioka LiquidScintillator Anti-Neutrino Detector (KamLAND). KamLAND's 13m diameter targetvolume provides a suitable environment to measure energy and positiondependence of the detected neutrino flux. A characteristic oscillation patternwould be visible for a baseline of about 10 m or less, providing a very cleansignal of neutrino disappearance into a yet-unknown, "sterile" state. Such ameasurement will be free of any reactor-related uncertainties. After 1.5 yearsof data taking the Reactor Antineutrino Anomaly parameter space will be testedat > 95% C.L.

Published
2013

46. Enhanced Constraints on theta13 from A Three-Flavor Oscillation Analysis of Reactor Antineutrinos at KamLAND

Author

Gando, A., Gando, Y., Ichimura, K., Ikeda, H., Inoue, K., Kibe, Y., Kishimoto, Y., Koga, M., Minekawa, Y., Mitsui, T., Morikawa, T., Nagai, N., Nakajima, K., Nakamura, K., Narita, K., Shimizu, I., Shimizu, Y., Shirai, J., Suekane, F., Suzuki, A., Takahashi, H., Takahashi, N., Takemoto, Y., Tamae, K., Watanabe, H., Xu, B. D., Yabumoto, H., Yoshida, H., Yoshida, S., Enomoto, S., Kozlov, A., Murayama, H., Grant, C., Keefer, G., Piepke, A., Banks, T. I., Bloxham, T., Detwiler, J. A., Freedman, S. J., Fujikawa, B. K., Han, K., Kadel, R., O'Donnell, T., Steiner, H. M., Dwyer, D. A., McKeown, R. D., Zhang, C., Berger, B. E., Lane, C. E., Maricic, J., Miletic, T., Batygov, M., Learned, J. G., Matsuno, S., Sakai, M., Horton-Smith, G. A., Downum, K. E., Gratta, G., Efremenko, Y., Perevozchikov, O., Karwowski, H. J., Markoff, D. M., Tornow, W., Heeger, K. M., and Decowski, M. P.

Published
2011

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