Examination of experimental conditions for the production of proton-rich and neutron-rich hypernuclei

Abstract

After the demonstration of the feasibility of hypernuclear spectroscopy with heavy-ion beams, the HypHI Collaboration will next focus on the study of proton-and neutron-rich hypernuclei. The use of a fragment separator for the production and separation of rare isotope beams is a crucial aspect to producing hypernuclei far from the stability line. Precise spectroscopy of exotic hypernuclei is planned to be carried out at the GSI and later at the FAIR facility with the FRS and Super-FRS fragment separators. A systematic study and an optimization analysis were performed in order to determine optimal experimental conditions for producing hypernuclei with high isospin. The optimal conditions are obtained based on theoretical models for the heavy-ion induced reaction and hypernuclei production. Experimental efficiencies for the production of exotic secondary beams were also taken into account via Monte Carlo simulations of the fragment separator. The developed methodology is presented to deduce the expected yields of 8 Λ Be and subsequently other proton-rich and neutron-rich hypernuclei.

Production of light hypernuclei with light-ion beams and targets

“…The hypernuclear yields in the present work are smaller than those in Ref. [26], and the form of Z-N plane population is different. The differences are due to that in Ref.…”

“…The differences are due to that in Ref. [26] the geometrical cross sections instead of the inelastic cross sections were wrongly taken to estimate the hypernuclear yields, and breakup of the hot primary hyperresidues was not considered [49]. Actually, the production cross sections are quite sensitive to the adopted excitation energies, since the breakup probability is proportional to (E x −U ) 3n/2−5/2 , where U is the Coulomb barrier and n is the number of cold residues after breakup [46].…”

Strangeness in nuclear physics

“…The measured mean life was found to be 86 +33 −26 ps, which is two to three times shorter than lifetimes measured in this hypernuclear mass range in more recent, better controlled (π + , K + ) experiments at KEK (Bhang et al, 1998;Park et al, 2000), as demonstrated in Table VI. More recently, the HypHI Collaboration at GSI reported lifetimes of 3 Λ H and 4 Λ H produced by bombarding a carbon target with a 2 GeV/nucleon 6 Li beam (Rappold et al, 2013a). The lifetime of 3 Λ H has also been measured in heavy-ion central collisions, by the STAR Collaboration at the BNL-RHIC collider (Abelev et al, 2010) and by the ALICE Collaboration at CERN-LHC (Adam et al, 2016a).…”

Exotic hypernuclear systems and heavy ion collisions

“…Various aspects of hypernuclear production in heavy-ion collisions were considered in many works, see [26][27][28]. Estimates [27] show that observation not only single-Λ, but also double-Λ hypernuclei including 5 ΛΛ H and 5 ΛΛ He at the NICA complex is quite feasible.…”