Speaker
Mr.
Andrey Danilov
(NRC Kurchatov Institute)
Description
An experiment was done to search for states with a neutron halo in 12B. The measurements were carried out at the cyclotron of the University of Jyvaskyla (Finland) using Large Scattering Chamber (LSC). The idea of the work was to search for two states with the expected neutron halo, 1¯ and 2¯.
Differential cross sections with excitation of 12B states, including abovementioned states, were observed.
The preliminary calculations on halo radii by the method of asymptotic normalization coefficients for the 2¯ and 1¯ states gave following values: 5.9 fm and 7.7 fm, which is much larger than the radius of the valence neutron in the ground state. This confirms the presence of a neutron halo in these states, which are in a discrete spectrum.
An unexpected result was obtained for the 3¯, 3.39 MeV state, which is in continium 19 keV above the decay threshold 12B → 11B + n, estimation for its halo radius is ~ 6.5 fm. This indicates that the halo is present in this state as well. Until now, the neutron halo in unbound states has been observed only for the members of the rotational bands.
Primary author
Mr.
Andrey Danilov
(NRC Kurchatov Institute)
Co-authors
Prof.
Alexey Ogloblin
(National Research Center «Kurchatov Institute»)
Dr.
Alla Demyanova
(NRC Kurchatov Institute, 1, Akademika Kurchatova pl., Moscow, 123182, Russia)
Mr.
Daniyar Janseitov
(Institute of Nuclear Physics, National Nuclear Center of Republic of Kazakhstan, ul. Ibragimova 1, Almaty, 050032 Republic of Kazakhstan.)
Mr.
Grigory Tyurin
(Jyvaskylan yliopisto, Seminaarinkatu 15, 40014 Jyvaskyla, Finland)
N Burtebaev
(Institute of Nuclear Physics, National Nuclear Center of Republic of Kazakhstan)
Prof.
Sergey Goncharov
(Faculty of Physics, Moscow State University, Moscow, 119991 Russia)
Mr.
Sergey Khlebnikov
(Khlopin Radium Institute, St.-Petersburg, Russia)
Prof.
Tatiana Belyaeva
(Universidad Autonoma del Estado de Mexico, Codigo Postal 50000, Toluca, Mexico)
Mr.
Vladimir Maslov
(Joint Institute for Nuclear Research, ul. Joliot-Curie 6, Dubna, Moscow oblast, 141980 Russia)
Dr.
Wladislaw Trzaska
(Jyvaskyl ¨ an yliopisto, Seminaarinkatu 15, 40014 Jyvaskyla, Finland)
Mr.
Yerzhan Muhkamejanov
(Al-Farabi Kazakh National University, av. al-Farabi,71, Almaty, Republic of Kazakhstan)
Mr.
Yury Sobolev
(Joint Institute for Nuclear Research, ul. Joliot-Curie 6, Dubna, Moscow oblast, 141980 Russia)