- 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, 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;
- Dell’Oro, S
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.