228 research outputs found
Fusion Cross Sections for the Proton Drip Line Nucleus 17F at energies below the coulomb barrier
The fusion-fission cross section for the system 17F + 208Pb involving the drip line nucleus 17F has been measured at energies in the vicinity of the Coulomb barrier. No enhancement of the fusion-fission yields due to breakup or to a large interaction radius was observed
Удвоение памяти для набора программ в ЭВМ "Проминь"
In previous work, we proposed a modal fragment of the sit-uation calculus called ES, which fully captures Reiter’s ba-sic action theories. ES also has epistemic features, includ-ing only-knowing, which refers to all that an agent knows in the sense of having a knowledge base. While our model of only-knowing has appealing properties in the static case, it appears to be problematic when actions come into play. First of all, its utility seems to be restricted to an agent’s initial knowledge base. Second, while it has been shown that only-knowing correctly captures default inferences, this was only in the static case, and undesirable properties appear to arise in the presence of actions. In this paper, we remedy both of these shortcomings and propose a new dynamic semantics of only-knowing, which is closely related to Lin and Reiter’s notion of progression when actions are performed and where defaults behave properly
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Experimental study of the Ni56(He3,d)Cu57 reaction in inverse kinematics
Measurements of (He3,d) reactions can provide information on the proton widths of states that play a role in astrophysically important (p,γ) reactions. We report on the first study of the (He3,d) reaction in inverse kinematics with a Ni56(T1/2=6.1 d) ion beam. The Q-value resolution of ~keV achieved in this experiment was sufficient to separate the transitions populating the ground state and the 1/2 - 5/2- doublet at Ex~1.1 MeV in Cu57. Prospects for similar (He3,d) experiments with improved energy resolution are also discussed
Direct decay from the superdeformed band to the yrast line in 66152Dy86
A number of single step linking transitions were observed in 152Dy. The first superdeformed (SD) band was linked to the normal yrats states and its spin, parity and excitation energy was established. An angular distribution analysis of the 4011 keV transition was performed to determine the spin of the 11893 keV SD level. The excitation energy of the lowest SD band member was 10644 keV and its spin and parity was determined to be 24+
Study of the 56Ni(d, p)57 Reaction and the Astrophysical 56Ni(p, γ)57Cu Reaction Rate
The single-particle character of states outside the doubly magic (radioactive) nucleus 56Ni has been determined through a measurement of the (d, p) neutron transfer reaction using inverse kinematics. From the spectroscopic factors of the low-lying states in 57Ni, the astrophysically interesting yield for the 56Ni(p, γ) reaction to the mirror nucleus 57Cu has been calculated, utilizing charge symmetry. The rate for this reaction in the temperature range typical of novae, supernovae, and x-ray bursts is found to be more than 10 times higher than previously assumed
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
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