Related Experiment Videos
Further evidence for the decay K+ -->pi+nu(nu)
S Adler1, A O Bazarko, P C Bergbusch
1Brookhaven National Laboratory, Upton, New York 11973.
Physical Review Letters
|January 22, 2002
Summary
Researchers found additional evidence for the rare kaon decay K+ to pi+ plus neutrinos. A new event was observed, bringing the total to two, with an estimated background of 0.15 events.
Area of Science:
- Particle Physics
- Experimental Physics
- High Energy Physics
Background:
- Rare kaon decays provide sensitive probes of the Standard Model.
- The decay K+ --> pi+ nu(nu) is particularly sensitive to new physics beyond the Standard Model.
- Previous searches have established limits on its branching ratio.
Purpose of the Study:
- To search for the rare kaon decay K+ --> pi+ nu(nu) with increased sensitivity.
- To provide additional evidence for this rare decay mode.
- To refine the measurement of its branching ratio.
Main Methods:
- Analysis of data from a new experimental run using a dedicated detector.
- Selection of candidate events in a specific pion momentum range (211-229 MeV/c).
- Estimation of background contributions from other processes.
Main Results:
- One new event consistent with K+ --> pi+ nu(nu) was observed in the analyzed data.
- The total number of observed events in the combined data set is two.
- The estimated background is 0.15 +/- 0.05 events.
- The branching ratio was measured to be B(K+ --> pi+ nu(nu)) = 1.57(+1.75)(-0.82)x10^-10.
Conclusions:
- The new data provide additional evidence for the rare kaon decay K+ --> pi+ nu(nu).
- The measured branching ratio is consistent with theoretical predictions and previous results.
- This measurement contributes to the ongoing effort to precisely determine fundamental particle physics parameters.