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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Measurement of scattering lengths using K<sub>&pi;3</sub> decay

Baker, Troy 01 January 2000 (has links)
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 K<sub>e4</sub> 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, ë<sub>ð</sub> 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</inf> eids sind s . Here ds is phase shift which depends on the scattering length, 'a'. We deduce ð<sup>+</sup>ð<sup>0</sup> (ð<sup>0</sup>ð<sup>0</sup> ) 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 .

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