Search for the K 0 L → π 0 νν̄ at E 391 a Experiment

An Experiment for the K

The rare K decay K L → π 0 νν̄ is considered as one of ideal processes in the flavor physics to make a critical test for the standard model and a search for new physics beyond it. The E391a experiment at the KEK 12-GeV proton synchrotron is the first dedicated experiment for the K L → π 0 νν̄ decay. The experiment started a data taking in February 2004 aiming at an improvement of sensitivity from...

Search for the Decay K + → π + π 0 νν̄

The first search for the decay K + → π + π 0 ν ¯ ν has been performed with the E787 detector at BNL. Based on zero events observed in the kinematical search region defined by 90 MeV/c < P π + < 188 MeV/c and 135 MeV < E π 0 < 180 MeV, an upper limit B(K + → π + π 0 ν ¯ ν) < 4.3 × 10 −5 at 90% confidence level is established.

0 Further Search for the Decay K + → π + νν̄

A search for additional evidence for the rare kaon decay K+ → π+νν̄ has been made with a new data set comparable in sensitivity to the previous exposure that produced a single event. No new events were found in the pion momentum region examined, 211 < P < 229 MeV/c. Including a reanalysis of

New results for K+→π+νν at low π+ momentum from BNL E949

The BNL E949 experiment was a successor to BNL E787 and was aimed to measure the branching ratio of the K+ → π+νν̄ decay. After detector upgrades were made, data equivalent to 1.7 × 1012 K+ decays at rest were collected in a 2002 physics run. The data were analyzed via a blind analysis with a technique called the “Bifurcation Method”. In this report we present the results of a search for K+ → π+...

Measurement of the decay K 0 L → π 0 νν̄ DRAFT TECHNICAL DESIGN