Search for neutron-rich Λ hypernuclei in the (Kstopped−, π+) reaction

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Abstract. We carried out an experiment to produce the neutron-rich hypernucleus 6 Λ H via the (π − , K + ) reaction on 6 Li target at the pion beam momentum of 1.2 GeV/c (J-PARC E10). In order to calibrate the scale of the missing-mass or of the Λ binding energy of the hypernucleus, we also measured the 12 C(π + , K + ) 12 Λ C, p(π − , K + )Σ − and p(π + , K + )Σ + reactions. The experiment was performed at the J-PARC Hadron Hall K1.8 beam line in

Section: Epj Web Of Conferencesmentioning

confidence: 99%

Study on_Λ⁶H hypernucleus by the (π⁻,K⁺) reaction at J-PARC

Sugimura

Agnello

Ahn

et al. 2014

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“…This feature is demonstrated by the observation of 6 Λ He, 7 Λ Be, 8 Λ He, 9 Λ Be and 10 Λ B hypernuclei in emulsion experiments [2]. No unstable-core hydrogen Λ hypernuclei have been found so far, although the existence of the lightest possible one 6 Λ H was predicted in [1] and subsequently reinforced in estimates by Majling [3].…”

Section: Introductionmentioning

confidence: 95%

“…The first experimental attempt to produce neutron-rich hypernuclei was carried out at KEK [8] with the reaction (1) with K − at rest. Upper limits were obtained for the production of 9 Λ He, 12 Λ Be and 16 Λ C hypernuclei (on 9 Be, 12 C and 16 O targets respectively) in the range of (0.6 − 2.0) · 10 −4 /K − stop .…”

Section: Introductionmentioning

confidence: 99%

Neutron-rich hypernuclei: evidence for⁶_ΛH and search for⁹_ΛHe

Agnello

Benussi

Bertani

et al. 2012

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Abstract. The FINUDA experiment at DAΦNE, Frascati, has found evidence for the neutron-rich hypernucleus 6 Λ H studying (π + , π − ) pairs in coincidence from the K − stop + 6 Li → 6 Λ H + π + production reaction followed by 6 Λ H → 6 He + π − weak decay. The production rate of 6 Λ H undergoing this two-body π − decay has been found to be (2.9 ± 2.0) · 10 −6 /K − stop . Its binding energy has been evaluated to be B Λ ( 6 Λ H) = (4.0 ± 1.1) MeV with respect to 5 H + Λ, jointly from production and decay. A systematic difference of (0.98 ± 0.74) MeV between B Λ values derived separately from decay and from production has been tentatively assigned to the 6 Λ H 0 + g.s. → 1 + excitation. A similar investigation has been carried out for the neutron-rich hypernucleus 9 Λ He studying the K − stop + 9 Be → 9 Λ He + π + reaction in coincidence with the 9 Λ He → 9 Li + π − weak decay; an upper limit for the production rate of 9 Λ He undergoing the two-body π − decay has been found to be 4.2 ·10 −6 /K − stop (90% C.L.). a

“…No unstable-core hydrogen Λ hypernuclei have been found so far, although the existence of the lightest possible one 6 Λ H was predicted in [1] and subsequently reinforced in estimates by Majling [3]. The neutral-baryon excess in 6 Λ H, in particular, would be (N + Y)/Z = 5, with Y = 1 for a Λ hyperon, or N/Z = 4, larger than the maximal value in light nuclei, N/Z = 3 for 8 He [4]. Neutronrich light hypernuclei could thus go beyond the neutron drip line for ordinary nuclear systems.…”

Section: Introductionmentioning

confidence: 96%

“…The first experimental attempt to produce neutron-rich hypernuclei was carried out at KEK [8] by the reaction (1) with K − at rest. Upper limits were obtained for the production of 9 Λ He, 12 Λ Be and 16 Λ C hypernuclei (on 9 Be, 12 C and 16 O targets respectively) in the range of (0.6 − 2.0) · 10 −4 /K − stop .…”

Section: Introductionmentioning

confidence: 99%

Neutron-rich Λ-Hypernuclei study with the FINUDA experiment

Botta

2014

Abstract. The FINUDA experiment at DAΦNE, Frascati, has found evidence for the neutron-rich hypernucleus 6 Λ H studying (π + , π − ) pairs in coincidence from the K − stop + 6 Li → 6 Λ H + π + production reaction followed by 6 Λ H → 6 He + π − weak decay. The production rate of 6 Λ H undergoing this two-body π − decay has been found to be (2.9 ± 2.0) · 10 −6 /K − stop . Its binding energy has been evaluated to be B Λ ( 6 Λ H) = (4.0 ± 1.1) MeV with respect to ( 5 H + Λ), jointly from production and decay. A systematic difference of (0.98 ± 0.74) MeV between B Λ values derived separately from decay and from production has been tentatively assigned to the 6 Λ H 0 + g.s. → 1 + excitation. A similar investigation has been carried out for the neutron-rich hypernucleus 9 Λ He studying the K − stop + 9 Be → 9 Λ He + π + reaction in coincidence with the 9 Λ He → 9 Li + π − weak decay; an upper limit for the production rate of 9 Λ He undergoing the two-body π − decay has been found to be 4.2 ·10 −6 /K − stop (90% C.L.).