Analysis of 17 898τ+Decays at Rest

Abstract

The energy spectrum of the decay pions in T+ decay was obtained from a sample of 17 898 events. I t is found that the spectrum is adequately fitted by a squared matrix element of linear form, jMI2= l + a , X ( l b f~Q / m ,~) Y, with u7=0.131f 0.008. No evidence for C P noninvariance is found for T+ decays. A significant violation oi the 41= 4 rule is observed ior Kf -+ 37r decays Comparison with several theoretical models for K -+ 37r decays s11ou.s fair agreement betneen experiment and theory.

Energy Spectrum of theπ+inK+→π<

“…Barton, Kacser, and Rosen have shown 18 that if the final-state pions are in a pure 1=1 state, and the matrix elements are linear, then a r '/a r =-2, where a T refers to the TT~ in r + decay and is defined similarly to a T '. The two most recent and precise measurements for r decay known to us are a T = -0.090±0.012, 19 and a T =-0.113±0.0083. 20 We may combine these two measurements and compare the result with our slope for the linear spectrum, cv = 0.258±0.009: o; r ,/a T= :_2.44±0.18.…”