37 research outputs found
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
Evolution of the nuclear spin-orbit splitting explored via the <sup>32</sup>Si<i>(d,p)</i><sup>33</sup>Si reaction using SOLARIS
The spin-orbit splitting between neutron 1p orbitals at 33Si has been deduced using the single-neutron-adding (d,p) reaction in inverse kinematics with a beam of 32Si, a long-lived radioisotope. Reaction products were analyzed by the newly implemented SOLARIS spectrometer at the reaccelerated-beam facility at the National Superconducting Cyclotron Laboratory. The measurements show reasonable agreement with shell-model calculations that incorporate modern cross-shell interactions, but they contradict the prediction of proton density depletion based on relativistic mean-field theory. The evolution of the neutron 1p-shell orbitals is systematically studied using the present and existing data in the isotonic chains of = 17, 19, and 21. In each case, a smooth decrease in the separation of the - orbitals is seen as the respective p-orbitals approach zero binding, suggesting that the finite nuclear potential strongly influences the evolution of nuclear structure in this region
Factors shaping prayer frequency among 9- to 11-year-olds
This paper begins by reviewing the evidence from international research concerning the personal and social correlates of prayer frequency during childhood and adolescence. Overall these data continue to support the view that young people who pray not only report higher levels of personal wellbeing but also report higher levels of pro-social attitudes. These findings raise a research question of particular relevance within church schools regarding the factors that predict higher levels of prayer activity among students. The Student Voice Project offers data that can illuminate this research question. Among the 3,101 9- to 11-year old students who participated in the project 11% prayed daily, 9% at least once a week, 32% sometimes, 11% once or twice a year, and 37% never. The present paper tests the power of four sets of predictor variables to account for individual differences in prayer frequency among these students: personal factors (age and sex), psychological factors (using the three dimensional model of personality proposed by Eysenck), church attendance (self, mother, and father), and family discussion about prayer (mother, father, and grandparents). Multiple regression analyses identified the discussion of prayer with the mother as the single most important predictor. These findings locate the development of the practice of prayer within the home, even more than within the church
Precision studies of QCD in the low energy domain of the EIC
peer reviewedThis White Paper aims at highlighting the important benefits in the science reach of the EIC. High luminosity operation is generally desirable, as it enables producing and harvesting scientific results in a shorter time period. It becomes crucial for programs that would require many months or even years of operation at lower luminosity
Implicit Quantile Networks For Emulation in Jet Physics
The ability to model and sample from conditional densities is important in
many physics applications. Implicit quantile networks (IQN) have been
successfully applied to this task in domains outside physics. In this work, we
illustrate the potential of IQNs as components of emulators using the
simulation of jets as an example. Specifically, we use an IQN to map jets
described by their 4-momenta at the generation level to jets at the event
reconstruction level. The conditional densities emulated by our model closely
match those generated by , while also enabling faster jet
simulation
Coulomb excitation of Mo96
The neutron-rich strontium, zirconium, and molybdenum nuclei have been observed to undergo a dramatic evolution, becoming strongly deformed around =60, sometimes interpreted as a quantum phase transition between “normal” and intruder configurations. Key to understanding this evolution is to understand the configurations in isolation, in regions where interference can be neglected. A deformed coexisting configuration is inferred from the presence of a 0+ 2 state which decreases in excitation energy with increasing neutron number, becoming the first-excited state at 98Mo. We present here the results of a low-energy Coulomb-excitation measurement of the nucleus 96Mo, extracting ( 2) values and quadrupole moments. It is found that, while the ( 2) values agree with those found in the literature, there is a significant disagreement with literature spectroscopic quadrupole moments. The results are compared with shell-model calculations using a 88Sr core with good agreement found, likely indicating that intruder structures do not significantly impact the ground-state structure, in contrast with the heavier molybdenum isotopes
Observation of Three-Neutron Sequential Emission from <sup>25</sup>O
Background: Measurements of neutron-unbound states can test nuclear models in very neutron-rich
nuclei that in some cases cannot be probed with other methods.
Purpose: Search for highly excited neutron-unbound states of 25O above the three neutron
separation energy.
Method: The decay energy of 25O was reconstructed using the invariant mass spectroscopy
method. A 101.3 MeV/u 27Ne beam collided with a liquid deuterium target. Two-proton removal
reactions populated excited 25O that decayed into three neutrons and an 22O fragment. The
neutrons were detected by arrays of plastic scintillator bars, while a 4 Tm dipole magnet placed
directly after the target redirected charged fragments to a series of charged-particle detectors. The
data were compared with detailed Monte Carlo simulations of the reaction process and subsequent
decay.
Results: The data show evidence of neutron-unbound level(s) in 25O at an excitation energy of
about 9 MeV which decay sequentially by the emission of three neutrons to 22O.
Conclusion: The observation of resonance strength in 25O at about 9 MeV is consistent with
shell-model/eikonal calculations for the two-proton removal reaction from 27Ne.</p