196 research outputs found
New insight into the low-energy He spectrum
The spectrum of He was studied by means of the He(,)He
reaction at a lab energy of 25 MeV/n and small center of mass (c.m.) angles.
Energy and angular correlations were obtained for the He decay products by
complete kinematical reconstruction. The data do not show narrow states at
1.3 and 2.4 MeV reported before for He. The lowest resonant
state of He is found at about 2 MeV with a width of 2 MeV and is
identified as . The observed angular correlation pattern is uniquely
explained by the interference of the resonance with a virtual state
(limit on the scattering length is obtained as fm), and with
the resonance at energy MeV.Comment: 5 pages, 4 figures, 2 table
Three-body correlations in direct reactions: Example of Be populated in reaction
The Be continuum states were populated in the charge-exchange reaction
H(Li,Be) collecting very high statistics data ( events) on the three-body ++ correlations. The
Be excitation energy region below MeV is considered, where the
data are dominated by contributions from the and states. It is
demonstrated how the high-statistics few-body correlation data can be used to
extract detailed information on the reaction mechanism. Such a derivation is
based on the fact that highly spin-aligned states are typically populated in
the direct reactions.Comment: submitted to Physical Review
New broad 8Be nuclear resonances
Energies, total and partial widths, and reduced width amplitudes of 8Be
resonances up to an excitation energy of 26 MeV are extracted from a coupled
channel analysis of experimental data. The presence of an extremely broad J^pi
= 2^+ ``intruder'' resonance is confirmed, while a new 1^+ and very broad 4^+
resonance are discovered. A previously known 22 MeV 2^+ resonance is likely
resolved into two resonances. The experimental J^pi T = 3^(+)? resonance at 22
MeV is determined to be 3^-0, and the experimental 1^-? (at 19 MeV) and 4^-?
resonances to be isospin 0.Comment: 16 pages, LaTe
Alpha cluster resonance structure of light nuclei close to coulomb barrier
The aim of this experimental study is to
investigate the structure of the 19F nuclei at
energies representing astrophysical interest.
Here we study the resonant interaction 15N+4He
in the cyclotron DC-60 in Astana
The TTIK approach for neutrons
We applied Thick Target Inverse Kinematics Method for a study of resonances
decaying through neutron emission. As a test we used a well-studied, because of
its role in s-process in stars, C(; n) reaction. The observed
energy resolution for the C(; n) excitation function was
60 keV, the largest contributions coming from the time structure of the
beam and the thickness of the neutron detector. These measurements demonstrated
the high efficiency of the approach and revealed a disagreement with R-matrix
calculations based on parameters of the most recent previous analysis
Spectroscopy of 9C via resonance scattering of protons on 8B
The structure of the neutron-deficient 9C isotope was studied via elastic
scattering of radioactive 8B on protons. An excitation function for resonance
elastic scattering was measured in the energy range from 0.5 to 3.2 MeV in the
center-of-momentum system. A new excited state in 9C was observed at an
excitation energy of 3.6 MeV. An R-matrix analysis indicates spin-parity 5/2-
for the new state. The results of this experiment are compared with Continuum
Shell Model calculations.Comment: 9 pages, 8 figures, 3 table
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