Observation of new states of the 7He isotope

Spectroscopy ofHe7using theBe9(HeRenzi1, Raabe2, Randisi3 et al. 2016Phys. Rev. C5010View full textAdd to dashboardCite

“…In a recent study of π − -induced reactions, Gurov et al [15] set an upper limit of 0.5 MeV on the widths for the first three excited states of 7 He. According to our data, a resonance with such FWHM gives a χ 2 higher than 300; thus, it can be excluded at 99% confidence level (CL).…”

“…[4], replacing the carbon target by a liquid-hydrogen target; the low-lying resonance was not confirmed. Furthermore, no evidence for a state below 1 MeV has been found in five other experiments [5,11,12,14,15] using a variety of techniques. These studies have provided positive signs of a first-excited state at higher energy, although these observations are not completely in agreement among themselves, as shown in Fig.…”

Formation of 8He in the 9Be(π–, p)X and 10B(π–, pp)X Stopped Pion Absorption Reactions

“…It is noteworthy that we successfully used the stopped pion absorption reaction to study the structure of levels of other heavy helium isotopes 6 He [16,17] and 7 He [18][19][20].…”

Neutron Structure of the Ground State of 7He

“…1). The multibody dis- The missing mass spectrum obtained on correlation measurements of the 11 B(π − , dd)X reaction is shown in [2]. As in the case of Fig.…”

“…Here we concentrate on the decays resulting from the 9 Be(π − , d)X and 11 В(π − , dd)X reactions. The boron data were published in [2], but the proposed novel approach to study the configuration of 1) e-mail: chernyshev@mephi.ru the ground state of 7 He is used here for the first time. Also, the results of the measurements on beryllium targets are new.…”