Measurement of scattering lengths using Kπ3 decay
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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 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, incorporating Chew and Mandelstam's 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. 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 W=2a20-5a2 0=0.540±0.007stat +0.005-0.007syst .
DegreeDoctor of Philosophy (Ph.D.)
DepartmentPhysics and Engineering Physics
ProgramPhysics and Engineering Physics
CommitteeRangacharyulu, Chilakamarri (Chary)
Copyright DateJanuary 2000