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Title: K$sup -$-MESON CAPTURES BY BOUND NEUTRONS

Journal Article · · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

Experimental data are presented for K/sup -/-meson captures on bound neutrons and on two bound nucleons. K/sup -/-capture stars of only one prong and of only two prongs which are gray or black were analyzed in an effort to understand the basic neutron and 2 nucleon capture reactions. The same model that was used to explain the captures on bound protons has been extended to apply to bound neutrons. The average SIGMA -hyperon nuclear potential is determined to be 35 plus or minus 10 Mev attractive. This potential, coupled with the previously determined Coulomb potential of 10 plus or minus 3 Mev and the momentum of the capture nucleon, causes an estimated /sup 0/ pi /sup -/, and DELTA /sup +/ pi /sup -/, respectively, to be trapped in hound energy states. This high trapping probability leads to a high escape probability of 0.8 plus or minus 0.1 for SIGMA hyperons in unbound states and a corresponding SIGMA /sup +/- or E/sup -/-hyperon charge exchange cross section of 11/sub -6/ millibarns per neutron or proton, respectively, in the Ag nucleus. The proton-to-neutron K/ sup -/--capture ratio is found to be 4/sub -2//sup +4/. The fraction of K/sup -/- captures on neutrons that leads to the reaction DELTA /sup 0/ pi /sup -/ is 0.00/sub -0.0//sup +0.13/. The results indicate that most of the K/sup -/- mesons are captured in the interior of the nucleus. The numbers of multinucleon K/sup -/ captures which occur by the reactions SIGMA /sup +/n, SIGMA /sup -/p, and SIGMA /sup -/n are estimated t o be 1.3/sub -0.9//sup +2.2/, 0.0/sub -0.0// sup +1.5/, and 0.4/sub -0.4/ /sup +1.0 /%, respectively. The data of this experiment are consistent with the reaction rates of 2: 1: 1 1/4: 0: 1/2: 1/2:0 for SIGMA /sup -/ pi /sup +/, SIGMA /sup +/ pi /sup -/, SIGMA /sup 0/ pi /syo 0/, DELTA /sup 0/ pi /sup 0/, ly. (auth)

Research Organization:
Univ. of California, Livermore
NSA Number:
NSA-12-007986
OSTI ID:
4325801
Journal Information:
Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Vol. Vol: 109; Other Information: Orig. Receipt Date: 31-DEC-58
Country of Publication:
Country unknown/Code not available
Language:
English