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Koester, L.J. Edwards, Ralph Thomas 2011-07-14T14:55:54Z 2011-07-14T14:55:54Z 10000-01-01 1970 Decays of the type K+/- -> pi+/- pi0 gamma, have been observed in an experiment performed at Argonne National Laboratory using a scintillation counteroptical spark chamber arrangement, and a 3.5 Bev/c K±- beam. These decays are interesting because the interference of two competing mechanisms for this decay may produce asymmetries in the partial decay rates for K+ and K- into this mode. The mechanisms are internal bremsstrahlung and a hypothetical direct process in which the gamma is produced within the decay vertex. The experiment was performed to compare the partial rates of + +00 - -00 K ~ 1{ 1{ 1{ and K ~ 1{ 1{ n: as a method of observing CP asymmetries. Among the 3n: decays we have found 33 events of the type K+ - pi+pi0pi0 and K- -> pi-pi0pi0 of the type K- .~ - 0 1{ 1{ ,. These events were separated from the 3n: decays by observing an angle of the charged pion relative to the K±- direction larger than that kinematically allowed for the 3n: decays. The angles of the decay product in K+/- -> pi+pio gamma were used to calculate the K rest system energies and angles of the decay products. The distribution of the cosine of the angle between the charged pion and the gamma in the center of mass was used to fit parameters corresponding to the fraction of direct decays in the sample. The fraction of direct decays is consistent with zero, and the partial decay rate for direct decay,excluding interference between direct and internal bremsstrahlung amplitudes, is less than l0% (to 1 standard deviation) of the partial rate for internal bremsstrahlung for the kinetic energy of the charged pion between 58 and 90 Mev. The resulting upper limit for the asymmetries in the partial decay rates for K- -> pi- pio gamma, and [equation] one standard deviatjion for the same energy region. So, although the size of the direct process is small relative to internal bremsstrahlung, CP asymmetries have not been shown to be unobservable. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-14T14:55:54Z No. of bitstreams: 1 1970_edwardsr.pdf: 2146815 bytes, checksum: f21e4efcb2b73da8f1f4a6db472f3263 (MD5) Made available in DSpace on 2011-07-14T14:55:54Z (GMT). No. of bitstreams: 1 1970_edwardsr.pdf: 2146815 bytes, checksum: f21e4efcb2b73da8f1f4a6db472f3263 (MD5) Previous issue date: 1970 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-14T14:55:54Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:32:48-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 6065190 http://hdl.handle.net/2142/25809 en 1970 Ralph Thomas Edwards two pion radiative decays positive kaons negative kaons scintillation counter-optical spark chamber A search for direct processes in two pion radiative decays of positive and negative kaons Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.