First observation of the ΣN decay of the S = - 2 system

Watanabe, Toru; Ahn, J. K.; Akikawa, H.; Aoki, Shigeki; Arai, K.; Bahk, S. Y.; Baik, K. M.; Bassalleck, B.; Chung, M.; Davis, D. H.; Fukuda, T.; Hayata, H.; Hoshino, K.; Ichikawa, A. K.; Ieiri, M.; Iwata, Yoshiyuki; Iwata, Y. S.; Kakita, Y.; Kanda, H.; Kaneko, M.; Kawai, Takeshi; Kawasaki, M.; Kim, C. O.; Kim, J. Y.; Kim, S. J.; Kim, S. H.; Kondō, Y.; Kouketsu, T.; Lee, Y. L.; McNabb, J. W.; Mitsuhara, Manabu; Nagase, Y.; Nagoshi, C.; Nakazawa, Kimitaka; Noumi, H.; Ogawa, S.; Okabe, H.; Oyama, K.; Park, H. M.; Park, I. G.; Parker, Joseph D.; S., Y.; Rhee, J. T.; Rusek, A.; Shibuya, H.; Sim, K. S.; Saha, Pranab; Seki, Daikichi; Sekimoto, M.; Song, J.; Takahashi, Hajime; Takahashi, Toshiya; Takéutchi, F.; Tanaka, Hiroki; Tanida, K.; Tojo, J.; Torii, H.; Torikai, S.; Tsunemi, T.; Tovee, D.N.; Ushida, N.; Yamamoto, K.; Yasuda, N.; Yang, Jing; Yoon, C. J.; Yoon, C. S.; Yosoi, M.; Yoshida, T.; Zhu, Lei

doi:10.1140/epja/i2007-10465-7

Cited by 5 publications

(10 citation statements)

References 9 publications

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“…The calculations refer to the mass range corresponding to the experimentally accessible 10 Be and 13 B hypernuclei. Practically, the calculations are performed with a mass number A = N + Z + 2 = 12 and an equal number of neutrons and protons, N = Z = 5.…”

Section: Resultsmentioning

confidence: 99%

“…The calculation is performed for double-hypernuclei with mass number A = 10-13 to mimic the behavior of the experimentally accessible finite hypernuclei 10 Be and 13 B. As in [12], for the function ψ (r) we use a 1s 1/2 harmonic oscillator wave function; its frequency ω = 13.6 MeV is obtained from the fit of [19] of the experimental binding energies of 6 He, 10 Be, and 13 B. The energies of the initial with momentum k is given by k 0 = m + k 2 /(2m ) + V , where for the binding term we adopt the value V = − ω = −13.6 MeV.…”

Section: Formalismmentioning

confidence: 99%

“…Indeed, only a few doublehypernuclei events have been studied experimentally up to date. In the KEK-176 and KEK-373 experiments, 4 H, 6 He, and 10 Be have been identified, while less unambiguous events were recorded for 6 He and 10 Be in the 1960s and for 13 B in the early 1990s [5]. The observation of the so-called NAGARA event implies a weak and attractive interaction, i.e., a bond energy B ( 6 He) ≡ B ( 6 He) − 2B ( 5 He) = (0.67 ± 0.17) MeV [6].…”

Section: Introductionmentioning

confidence: 99%

“…Antisymmetry constraints on the initial state restrict the pair to be coupled to S = 0 and J = 0, thus only two nonmesonic decay channels are accessible: 1 S 0 → 1 S 0 and 1 S 0 → 3 P 0 in spectroscopic notation. No data are available on these decays, apart from the claim for the observation of a single event at KEK [10]. The experimental signature of a → n decay is clear, i.e., the emission of a large momentum (∼425 MeV), but the major problem is that these events are expected to be somewhat rare.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper we present a microscopic calculation of both the -and nucleon-induced decay rates for doublehypernuclei by using a nuclear matter formalism; both one-and two-nucleon stimulated processes, N → nN and N N → nN N , are taken into account, while the → nn decay channel is not considered here because, requiring a change in strangeness of two units, it is much less likely than the other -induced processes. Results for finite hypernuclei in the mass range of the empirically interesting 10 Be and 13 B systems are reported within the local density approximation. The same microscopic approach showed that Pauli exchange and ground-state correlation contributions are very important for a detailed calculation of the rates, the asymmetry parameter, and the nucleon emission spectra in the nonmesonic weak decay of hypernuclei [3,[15][16][17].…”

Section: Introductionmentioning

confidence: 99%

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Nonmesonic weak decay of double-Λhypernuclei: A microscopic approach

Bauer

Garbarino²,

Peña

2015

Phys. Rev. C

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The nonmesonic weak decay of double-hypernuclei is studied within a microscopic diagrammatic approach. In addition to the nucleon-induced mechanism, N → nN and N N → nN N , widely studied in singlehypernuclei, additional hyperon-induced mechanisms, → n, → 0 n, and → − p, are accessible in double-hypernuclei and are investigated here. As in previous works on single-hypernuclei, we adopt a nuclear matter formalism extended to finite nuclei via the local density approximation and a one-meson exchange weak transition potential (including the ground-state pseudoscalar and vector octets mesons) supplemented by correlated and uncorrelated two-pion-exchange contributions. The weak decay rates are evaluated for hypernuclei in the region of the experimentally accessible light hypernuclei 10 Be and 13 B. Our predictions are compared with a few previous evaluations. The rate for the → n decay is dominated by K-, K * -, and η-exchange and turns out to be about 2.5% of the free decay rate, free , while the total rate for the → 0 n and → − p decays, dominated by π -exchange, amounts to about 0.25% of free . The experimental measurement of these decays would be essential for the beginning of a systematic study of the nonmesonic decay of strangeness −2 hypernuclei. This field of research could also shed light on the possible existence and nature of the H dibaryon.

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Section: Resultsmentioning

confidence: 99%