Publications [#248711] of Christopher Walter

Papers Published
  1. Renshaw, A; Abe, K; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Tomura, T; Ueno, K; Yokozawa, T; Wendell, RA; Irvine, T; Kajita, T; Kaneyuki, K; Lee, KP; Nishimura, Y; Okumura, K; McLachlan, T; Labarga, L; Berkman, S; Tanaka, HA; Tobayama, S; Kearns, E; Raaf, JL; Stone, JL; Sulak, LR; Goldhabar, M; Bays, K; Carminati, G; Kropp, WR; Mine, S; Smy, MB; Sobel, HW; Ganezer, KS et al., First indication of terrestrial matter effects on solar neutrino oscillation., Physical Review Letters, vol. 112 no. 9 (March, 2014), pp. 091805 [pdf], [doi] .

    Abstract:
    We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2 ± 1.1(stat) ± 0.5(syst)]%, which deviates from zero by 2.7 σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4 × 10(-5)  eV(2) ≤ Δm 2(21) ≤ 7 × 10(-5) eV(2) and large mixing values of θ12, at the 68% C.L.