Binding Energy of Tritium Hyperfragments

Abstract

Emulsion stacks of Ilford G-5 exposed to 7r~-meson and ir~-meson beams of the Berkeley Bevatron have been scanned for iT-meson and hyperon events. An event initiated by a 3.0-Bev TT~ meson is described which is interpreted as mesonic decay of a tritium hyperfragment according to the scheme: iH?*-+p-\-p+n+7r~+Q. All of the charged particles from the decay come to rest in the stack. The binding energy of the A 0 is found to be 1.4±0.6 Mev. Two additional cases of the same decay scheme are described, one produced in a iC~-capture star, another in a 4.3-Bev iT star, yielding binding energies B.E. (A 0 ) < 1.3±0.6 Mev and B.E. (A 0 ) =3.3±2.0 Mev, respectively. A weighted average of these three events gives B.E.(A°) = 1.4±0.5 Mev, and of all iH 3 * events reported, including those found by other workers, B.E.(A°)=0.5zfc:0.3 Mev.

K Mesons and Hyperons their strong and weak interactions

“…A similar arrangement at Brookhaven has been described by Harris, Orear and Taylor (1956). Partly owing to the longer time of flight for the particles, due to the geometrical arrangement, and also because of the lower proton energy available, the K+/T+ ratio reported in this beam (375 MeV/C) is about 1/600, which corresponds to a ratio of about 1% at the target.…”

“…Consequently the observation that quite a high proportion of events have a low T -energy provides evidence against spin 1+ for the T meson. This case against spin 1+ was already stated strongly by Orear, Harris and Taylor (1956) and has become increasingly strong as further data have accumulated. Since the empirical result (4.14) does have an upward slope, it is possible to make spin 1+ appear somewhat less unacceptable than it does with the simplest estimates, by invoking a suitable energy dependence for a,, in the estimate (4.13) and by the inclusion of higher configurations (Eisenberg, Lomon and Rosendorff 1956).…”

“…?These T+ events consist of the following: 386 events by Baldo-Ceolin, Bonetti, Greening, Limentani, Merlin andVanderhaege (1957), 191 events by Haddock (1956 andprivate communication), 106 events by , 72 events by Orear, Harris and Taylor (1956), 33 events by Heckman, Smith and Barkas (1956 b), 33 events (line scan) by Bhowmik, Evans, van Heerden and Prowse (1956), 23 events (unbiased) by Brene, Hansen, Hooper and Scharff (1956) and 49 events by Feld, Odian, Ritson and Wattenberg (1955).…”

“…The lines OB, OC divide this allowed region into three equal parts and points Y and Z obtained by reflecting X in OC, and then Y in OB, represent configurations with the same pion energies but a different distribution of charges. The data on 219 events are plotted in this manner in figure 13, due to Orear, Harris and Taylor (1956) ; the distribution of events clearly has a strong component which is symmetrical between the three pions. Unfortunately it is not possible to conclude generally from this that the T decay amplitude itself is predominantly symmetrical between the pions, although this is the simplest interpretation with spin 0-for the T particle ; with this assumption a limit may be placed on the non-symmetrical component, which is of interest in discussing the isotopic spin state of the final pions (cf.…”

“…The Nuclear Interaction and Decay of K-Particles Despite the low Kintensities available in the accelerator beams up to the present (cf. Q 3.3), studies of Kparticle interactions (both in flight and at the end of their range) with emulsion nuclei have been reported by a considerable number of groups (Chupp, Goldhaber, Goldhaber and Webb 1955, Fry, Schneps, Snow and Swami 1955a, b, George, Herz, Noon and Solntseff 1956, Hornbostel and Salant 1956, Haskin, Bowen and Schein 1956, quoted by S. Goldhaber 1956, Fournet and). These data have recently been summarized and discussed by .…”