Measurement of Scattering Lengths Using Kð3 Decay

by Baker, Troy

Abstract (Summary)
The determination of N-N and ðð scattering lengths is of fundamental importance in the studies of hadron dynamics. A direct measurement of ðð scattering lengths is impossible due to a lack of processes with just two pions in both the initial and final state. Therefore indirect methods must be used. In the past, ðN ? ððN and Ke4 decay[1] have been employed. These analyses are complicated due to problems of (a) extrapolation to threshold, (b) contribution of higher multipoles, and (c) inelasticity effects. In this thesis we present a novel analysis of stopped K+p3 decays &parl0;K+ ? p+p0p0&parr0; to deduce the scattering lengths ( a00 and a20 ) in a nearly model independent way. The model of Sawyer and Wali[2], incorporating Chew and Mandelstam's[3] result for pp scattering, was used to analyze the data. The data is a kinematically complete determination of Kp3 decays, a byproduct of the T-violation experiment at KEK[4]. It is fit to an amplitude At' s1,s2,s3 =-l 2lp 2lp+12 t20s1 +t20 s2+13t0 0s3-t 20s3 0.1 where ë, ëð are the Kð ? ðð and ðð ? ðð coupling constants, 'si' are the center of mass energies of pion pairs and, 'tI' (' I' = 0, 2) is the S wave scattering amplitude for isospin I given by the Roy equation: tIs=ss-4m2p eids sind s . Here ds is phase shift which depends on the scattering length, 'a'. We deduce ð+ð0 (ð0ð0 ) scattering lengths to be a00 = 0.199 ± 0.003('stat') ± 0.002(' syst') and a20 = -0.0285 ± 0.0008 stat+0.0012 -0.0007 ('syst'). This also is the first experimental determination of Weinberg's universal curve[5] W=2a20-5a2 0=0.540±0.007stat +0.005-0.007syst .
Bibliographical Information:

Advisor:Rangacharyulu, Chilakamarri (Chary)

School:University of Saskatchewan

School Location:Canada - Saskatchewan

Source Type:Master's Thesis

Keywords:k sub ð3 decay hadron dynamics physics ðð scattering


Date of Publication:01/01/2000

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