49 research outputs found
Translation in the Comparative Literature. Poetry of Victor Hugo Translated by Basil Schurat
Статтю присвячено компаративістським аспектам художнього перекладу, проаналізовано переклади поезій Віктора Гюго Василем Щуратом. The article is devoted comparative aspects in fiction literature’s translation, the analysis of poetry Victor Hugo Basil Schurat
Search for unbound 15Be states in the 3n+12Be channel
15Be is expected to have low-lying 3/2+ and 5/2+ states. A first search did
not observe the 3/2+ [A. Spyrou et al., Phys. Rev. C 84, 044309 (2011)],
however, a resonance in 15Be was populated in a second attempt and determined
to be unbound with respect to 14Be by 1.8(1) MeV with a tentative spin-parity
assignment of 5/2+ [J. Snyder et al., Phys. Rev. C 88, 031303(R) (2013)].
Search for the predicted 15Be 3/2+ state in the three-neutron decay channel. A
two-proton removal reaction from a 55 MeV/u 17C beam was used to populate
neutron-unbound states in 15Be. The two-, three-, and four-body decay energies
of the 12Be + neutron(s) detected in coincidence were reconstructed using
invariant mass spectroscopy. Monte Carlo simulations were performed to extract
the resonance and decay properties from the observed spectra. The low-energy
regions of the decay energy spectra can be described with the first excited
unbound state of 14Be (E_x=1.54 MeV, E_r=0.28 MeV). Including a state in 15Be
that decays through the first excited 14Be state slightly improves the fit at
higher energies though the cross section is small. A 15Be component is not
needed to describe the data. If the 3/2+ state in 15Be is populated, the decay
by three-neutron emission through 14Be is weak, less than or equal to 11% up to
4 MeV. In the best fit, 15Be is unbound with respect to 12Be by 1.4 MeV
(unbound with respect to $14Be by 2.66 MeV) with a strength of 7%.Comment: 6 pages, 5 figures, accepted in Physical Review
Population of 13Be in a Nucleon Exchange Reaction
The neutron-unbound nucleus 13Be was populated with a nucleon-exchange
reaction from a 71 MeV/u secondary 13B beam. The decay energy spectrum was
reconstructed using invariant mass spectroscopy based on 12Be fragments in
coincidence with neutrons. The data could be described with an s-wave resonance
at E = 0.73(9) MeV with a width of Gamma = 1.98(34) MeV and a d-wave resonance
at E = 2.56(13) MeV with a width of Gamma = 2.29(73) MeV. The observed spectral
shape is consistent with previous one-proton removal reaction measurements from
14B.Comment: Published in Phys. Rev.
Further Insights into the Reaction Be14(CH2,X)10He
A previously published measurement of the reaction of a 59 MeV/nucleon 14Be beam on a deuterated polyethylene target was further analyzed to search for 12He as well as initial state effects in the population of the 10He ground state. No evidence for either was found. A lower limit of about 1 MeV was determined for a possible resonance in 12He. In addition, the three-body decay energy spectrum of 10He could not be described by a reaction mechanism calculation based on the halo structure of the initial 14Be assuming a direct α-particle removal reaction
Neutron-Unbound Excited States of 23N
Neutron unbound states in 23N were populated via proton knockout from an 83.4 MeV/nucleon 24O beam on a liquid deuterium target. The two-body decay energy displays two peaks at E1∼100keV and E2∼1MeV with respect to the neutron separation energy. The data are consistent with shell model calculations predicting resonances at excitation energies of ∼3.6MeV and ∼4.5MeV. The selectivity of the reaction implies that these states correspond to the first and second 3/2− states. The energy of the first state is about 1.3 MeV lower than the first excited 2+ in 24O. This decrease is largely due to coupling with the πp−13/2 hole along with a small reduction of the N=16 shell gap in 23N
Two-Neutron Sequential Decay of O
A two-neutron unbound excited state of O was populated through a
(d,d') reaction at 83.4 MeV/nucleon. A state at (stat) (sys) keV with a width of MeV was observed above the
two-neutron separation energy placing it at 7.65 0.2 MeV with respect to
the ground state. Three-body correlations for the decay of O
O + show clear evidence for a sequential decay
through an intermediate state in O. Neither a di-neutron nor phase-space
model for the three-body breakup were able to describe these correlations
-cluster ANCs for nuclear astrophysics
Background. Many important -particle induced reactions for nuclear
astrophysics may only be measured using indirect techniques due to small cross
sections at the energy of interest. One of such indirect technique, is to
determine the Asymptotic Normalization Coefficients (ANC) for near threshold
resonances extracted from sub-Coulomb -transfer reactions. This
approach provides a very valuable tool for studies of astrophysically important
reaction rates since the results are practically model independent. However,
the validity of the method has not been directly verified.
Purpose. The aim of this letter is to verify the technique using the
O(Li,)Ne reaction as a benchmark. The Ne nucleus
has a well known state at excitation energy of 5.79 MeV with a width of
28 eV. Reproducing the known value with this technique is an ideal opportunity
to verify the method.
Method. The 1 state at 5.79 MeV is studied using the -transfer
reaction O(Li,)Ne at sub-Coulomb energies.
Results. The partial width for the state at excitation energy
of 5.79 MeV is extracted and compared with the known value, allowing the
accuracy of the method to be evaluated.
Conclusions. This study demonstrates that extracting the Asymptotic
Normalization Coefficients using sub-Coulomb -transfer reactions is a
powerful tool that can be used to determine the partial width of near
threshold states that may dominate astrophysically important nuclear reaction
rates. \end{description
Molecular Structures in T=1 states of 10B
Multi-center (molecular) structures can play an important role in light
nuclei. The highly deformed rotational band in 10Be with band head at 6.179 MeV
has been observed recently and suggested to have an exotic alpha:2n:alpha
configuration. A search for states with alpha:pn:alpha two-center molecular
configurations in 10B that are analogous to the states with alpha:2n:alpha
structure in 10Be has been performed. The T=1 isobaric analog states in 10B
were studied in the excitation energy range of E=8.7-12.1 MeV using the
reaction 1H(9Be,alpha)6Li*(T=1, 0+, 3.56 MeV). An R-matrix analysis was used to
extract parameters for the states observed in the (p,alpha) excitation
function. Five T=1 states in 10B have been identified. The known 2+ and 3-
states at 8.9 MeV have been observed and their partial widths have been
measured. The spin-parities and partial widths for three higher lying states
were determined. Our data support theoretical predictions that the 2+ state at
8.9 MeV (isobaric analog of the 7.54 MeV state in 10Be) is a highly clustered
state and can be identified as a member of the alpha:np:alpha rotational band.
The next member of this band, the 4+ state, has not been found. A very broad 0+
state at 11 MeV that corresponds to pure alpha+6Li(0+,T=1) configuration is
suggested and it might be related to similar structures found in 12C, 18O and
20Ne.Comment: 10 pages, 10 figures, accepted in Physical Review