TY - JOUR
T1 - Experimental investigation of ground-state properties of 7H with transfer reactions
AU - Caamaño, M.
AU - Roger, T.
AU - Moro, A. M.
AU - Grinyer, G. F.
AU - Pancin, J.
AU - Bagchi, S.
AU - Sambi, S.
AU - Gibelin, J.
AU - Fernández–Domínguez, B.
AU - Itagaki, N.
AU - Benlliure, J.
AU - Cortina–Gil, D.
AU - Farget, F.
AU - Jacquot, B.
AU - Pérez–Loureiro, D.
AU - Pietras, B.
AU - Raabe, R.
AU - Ramos, D.
AU - Rodríguez Tajes, C.
AU - Savajols, H.
AU - Vandebrouck, M.
N1 - Funding Information:
The authors thank Navin Alahari for the useful discussions and the careful reading of the manuscript, and Miguel Marqués for his help in the data analysis. The authors are deeply thankful to the technical staff at GANIL for their support and help. This work has been supported by the European Community FP7–Capacities –Integrated Infrastructure Initiative– contract ENSAR n ∘ 262010, and by the Spanish Ministerio de Economía y Competitividad under contracts FPA2009–14604–C02–01 and FPA2012–39404–C02–01 . M.C. acknowledges the support by the Spanish Ministerio de Economía y Competitividad through the Programmes “Ramón y Cajal” with the grant number RYC–2012–11585 and “Juan de la Cierva” with the grant number JCI2009–05477 . A.M.M. is partially supported by the project Ref. P20_01247 , funded by the Consejería de Economía, Conocimiento, Empresas y Universidad, Junta de Andalucía (Spain) and by “ERDF A way of making Europe.”
Publisher Copyright:
© 2022 The Authors
PY - 2022/6/10
Y1 - 2022/6/10
N2 - The properties of nuclei with extreme neutron–to–proton ratios, far from those naturally occurring on Earth, are key to understand nuclear forces and how nucleons hold together to form nuclei. 7H, with six neutrons and a single proton, is the nuclear system with the most unbalanced neutron–to–proton ratio known so far. However, its sheer existence and properties are still a challenge for experimental efforts and theoretical models. Here we report experimental evidences on the formation of 7H as a resonance, detected with independent observables, and the first measurement of the structure of its ground state. The resonance is found at ∼0.7 MeV above the 3H+4n mass, with a narrow width of ∼0.2 MeV and a 1/2+ spin and parity. These data are consistent with a 7H as a 3H core surrounded by an extended four-neutron halo, with a unique four-neutron decay and a relatively long half-life thanks to neutron pairing; a prime example of new phenomena occurring in what would be the most pure-neutron nuclear matter we can access in the laboratory.
AB - The properties of nuclei with extreme neutron–to–proton ratios, far from those naturally occurring on Earth, are key to understand nuclear forces and how nucleons hold together to form nuclei. 7H, with six neutrons and a single proton, is the nuclear system with the most unbalanced neutron–to–proton ratio known so far. However, its sheer existence and properties are still a challenge for experimental efforts and theoretical models. Here we report experimental evidences on the formation of 7H as a resonance, detected with independent observables, and the first measurement of the structure of its ground state. The resonance is found at ∼0.7 MeV above the 3H+4n mass, with a narrow width of ∼0.2 MeV and a 1/2+ spin and parity. These data are consistent with a 7H as a 3H core surrounded by an extended four-neutron halo, with a unique four-neutron decay and a relatively long half-life thanks to neutron pairing; a prime example of new phenomena occurring in what would be the most pure-neutron nuclear matter we can access in the laboratory.
KW - 7H
KW - Active target
KW - Hydrogen resonance
UR - https://www.scopus.com/pages/publications/85127783953
U2 - 10.1016/j.physletb.2022.137067
DO - 10.1016/j.physletb.2022.137067
M3 - Article
AN - SCOPUS:85127783953
SN - 0370-2693
VL - 829
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
M1 - 137067
ER -