SearcharxivSearch

arXiv subjects

Le Xuan Chung

Publications and source records attributed to Le Xuan Chung.

4 recordsLinked to original sources

Checking the $^8$Be anomaly with a two-arm electron positron pair spectrometer

We have repeated the experiment performed recently by Krasznahorkay et al., (Phys. Rev. Lett. 116, 042501 (2016)), which may indicate a new particle called X17 in the literature. In order to get a reliable, and independent result, we used a different type of electron-positron pair spectrometer which have a more simple acceptance/efficiency as a function of the correlation angle, but the other conditions of the experiment were very similar to the published ones. We could confirm the presence of the anomaly measured at the E$_x$=18.15 MeV resonance, and also confirm their absence at the E$_x$=17.6 MeV resonance, and at E$_p$= 800 keV off resonance energies.

nucl-ex

Ambiguities from nuclear interactions in the $^{12}$C($p,2p$)$^{11}$B reaction

We investigate the impact of ambiguities coming from the choice of optical potentials and nucleon-nucleon scattering cross sections on the spectroscopic factors extracted from the $^{12}$C($p,2p$)$^{11}$B reaction. These ambiguities are evaluated by analyzing the cross sections of the $^{12}$C($p,2p$)$^{11}$B reaction at 100 and 200 MeV within the framework of the distorted-wave impulse approximation with realistic choices of nuclear inputs. The results show that the studied ambiguities are considerably large in this energy region and careful choices of nuclear inputs used in the reaction calculations are required to extract reliable structure information.

nucl-th

The dominance of the $ν(0d_{5/2})^2$ configuration in the $N=8$ shell in $^{12}$Be from the breakup reaction on a proton target at intermediate energy

The momentum distribution of $^{11}$Be fragments produced by the breakup of $^{12}$Be interacting with a proton target at 700.5 MeV/$u$ energy has been measured at GSI Darmstadt. To obtain the structure information on the anomaly of the $N=8$ neutron shell, the momentum distribution of $^{11}$Be fragments from the one-neutron knockout $^{12}$Be(p,pn) reaction, measured in inverse kinematics, has been analysed in the distorted wave impulse approximation (DWIA) based on a quasi-free scattering scenario. The DWIA analysis shows a surprisingly strong contribution of the neutron $0d_{5/2}$ orbital in $^{12}$Be to the transverse momentum distribution of the $^{11}$Be fragments. The single-neutron $0d_{5/2}$ spectroscopic factor deduced from the present knock-out data is 1.39(10), which is significantly larger than that deduced recently from data of $^{12}$Be breakup on a carbon target. This result provides a strong experimental evidence for the dominance of the neutron $ν(0d_{5/2})^2$ configuration in the ground state of $^{12}$Be.

nucl-ex

Elastic proton scattering at intermediate energies as a probe of the $^{6,8}$He nuclear matter densities

The Glauber model analysis of the elastic $^{6,8}$He+$p$ scattering data at energies around 700 MeV/nucleon, measured in two separate experiments at GSI-Darmstadt, has been done using several phenomenological parametrizations of the nuclear matter density. By taking into account the new data points measured at the high momentum transfer, the nuclear matter radii of $^{6,8}$He were accurately determined from the Glauber model analysis of the data, with the spin-orbital interaction explicitly taken into account. The well-known geometry for the core and dineutron halo has been used with the new parametrizations of the $^{6}$He density to extract the detailed information on the structure of $^{6}$He in terms of the core and dineutron halo radii. An enhanced sensitivity of the data measured at the high momentum transfer to the core part of the $^{6,8}$He densities has been found.

nucl-ex