New limits on oscillation parameters for electron antineutrinos

Abstract The positron spectrum from the reaction ν e + p → e + + n has been measured at L =37.9 from the core of the Gosgen power reactor to search for neutrino oscillations of the type ν e ↔ x in the low mass parameter range. The results are consistent with the no neutrino oscillation hypothesis. Upper limits of δm 2 ⪕ 0.016 eV 2 (90% c.l..) for full mixing, and sin 2 2θ⪕0.17 (90% c.l.) in the limit of large mass parameters were determined. For the ratio of the integrated experimental yield to that predicted for the case of no oscillations a value of 1.05 ± 0.02 (statistical) ± 0.05 (systematic; 68% c.l.) was obtained.