New limit on the T-violating transverse muon polarization in K+-->pi0mu+nu decays

Area of Science:

• Particle Physics
• Experimental Physics
• Kaon Physics

Background:

• The Standard Model of particle physics allows for CP violation but not T violation.
• Investigating T-violation in kaon decays provides a sensitive probe for new physics beyond the Standard Model.

Purpose of the Study:

• To search for T-violating transverse muon polarization (P(T)) in the K+ --> pi(0)mu(+)nu decay.
• To determine the T-violation parameter Im(xi) and set new limits on its value.

Main Methods:

• Utilized kaon decays at rest for the experiment.
• Measured the transverse muon polarization in the specified decay channel.
• Analyzed data to extract P(T) and Im(xi) with statistical and systematic uncertainties.

Main Results:

• Obtained an improved value for P(T) = -0.0017 ± 0.0023(stat) ± 0.0011(syst).
• Established an upper limit for T-violation: |P(T)| < 0.0050.
• Determined Im(xi) = -0.0053 ± 0.0071(stat) ± 0.0036(syst) with an upper limit |Im(xi)| < 0.016.

Conclusions:

• The results provide stringent constraints on T-violation in kaon decays.
• These findings contribute to testing the validity of the Standard Model and searching for new physics phenomena.