We report on a direct search in NOMAD for a new 33.9 MeV/c(2) neutral particle (X) produced in pion decay in flight, pi --> muX followed by the decay X --> nue(+)e(-). Both decays are postulated to occur to explain the time anomaly observed by the KARMEN experiment. From the analysis of the data collected during the 1996-1998 runs with 4.1 x 10(19) protons on target, a single candidate event consistent with background expectations was found. The search is sensitive to a pion branching ratio BR(pi --> muX) > 3.7 x 10(-15), significantly smaller than previous experimental limits. (C) 2002 Elsevier Science B.V. All rights reserved. RI Vercesi, Valerio/C-6672-2008; Collazuol, Gianmaria/C-5670-2012; Soler, Paul/E-8464-2011; Moorhead, Gareth/B-6634-2009
New results on a search for a 33.9 MeV/c(2) neutral particle from pi(+) decay in the NOMAD experiment
CAVASINNI, VINCENZO;RODA, CHIARA MARIA ANGELA;
2002-01-01
Abstract
We report on a direct search in NOMAD for a new 33.9 MeV/c(2) neutral particle (X) produced in pion decay in flight, pi --> muX followed by the decay X --> nue(+)e(-). Both decays are postulated to occur to explain the time anomaly observed by the KARMEN experiment. From the analysis of the data collected during the 1996-1998 runs with 4.1 x 10(19) protons on target, a single candidate event consistent with background expectations was found. The search is sensitive to a pion branching ratio BR(pi --> muX) > 3.7 x 10(-15), significantly smaller than previous experimental limits. (C) 2002 Elsevier Science B.V. All rights reserved. RI Vercesi, Valerio/C-6672-2008; Collazuol, Gianmaria/C-5670-2012; Soler, Paul/E-8464-2011; Moorhead, Gareth/B-6634-2009I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
