Nuclear Theory·nucl-th
6 papers—5 primary·1 cross-listed
Thomas Schaefer (North Carolina State University)🇺🇸
We present a brief introduction to QCD, the QCD phase diagram, and non-equilibrium phenomena in QCD. We emphasize aspects of the theory that can be addressed using computational methods, in particular euclidean path integral Monte Carlo, fluid dynamics, kinetic theory, classical field theory and holographic duality.
The rich phenomena of deformations in neutron-deficient krypton isotopes such as the shape evolution with neutron number and the shape coexistence attract the interests of nuclear physicists for decades. It will be interesting to study such shape phenomena using a novel way, i.e., by thermally exciting the nucleus. So in this work, we develop the finite temperature covariant density functional theory for axially deformed nuclei with the treatment of pairing correlations by BCS approach, and apply this approach for the study of shape evolutions in Kr with increasing temperatures. For Kr, with temperature increasing, the nucleus firstly experiences a relatively quick weakening in oblate deformation at temperature MeV, and then changes from oblate to spherical at MeV. For Kr, its global minimum locates at quadroupole deformation and abruptly changes to spherical at MeV. The proton pairing transition occurs at critical temperature 0.6 MeV following the rule where is the proton pairing gap at zero temperature. The signatures of the above pairing transition and shape changes can be found in the curve of the specific heat. The single-particle level evolutions with the temperature are presented.
Kosho Minomo · Kouhei Washiyama · Kazuyuki Ogata
Total reaction cross sections of deuteron, , are calculated by a microscopic three-body reaction model. The reaction model has no free adjustable parameter and applicable to reactions at various deuteron incident energies and with both stable and unstable nuclei. The predicted are consistent with those evaluated by a phenomenological optical potential for MeV in which the potential has been parametrized. A simple formula of up to GeV, as a function of , the target mass number and its atomic number , is given.
C. Drischler · A. Carbone · K. Hebeler · A. Schwenk
Neutron matter is an ideal laboratory for nuclear interactions derived from chiral effective field theory since all contributions are predicted up to next-to-next-to-next-to-leading order (NLO) in the chiral expansion. By making use of recent advances in the partial-wave decomposition of three- nucleon (3N) forces, we include for the first time NLO 3N interactions in many-body perturbation theory (MBPT) up to third order and in self-consistent Green's function theory (SCGF). Using these two complementary many-body frameworks we provide improved predictions for the equation of state of neutron matter at zero temperature and also analyze systematically the many-body convergence for different chiral EFT interactions. Furthermore, we present an extension of the normal-ordering framework to finite temperatures. These developments open the way to improved calculations of neutron-rich matter including estimates of theoretical uncertainties for astrophysical applications.
A.S. Botvina (Frankfurt U., FIAS, ITP & Moscow, INR)🇩🇪 · K.K. Gudima (Kishinev, IAP)🇩🇪 · J. Steinheimer (Frankfurt U., FIAS)🇩🇪 · M. Bleicher (Frankfurt U., FIAS, ITP)🇩🇪 · J. Pochodzalla (Mainz U., HIM, IKP)🇩🇪
In relativistic ion collisions there are excellent opportunities to produce and investigate hyper-nuclei. We have systematically studied the formation of hypernuclear spectator residues in peripheral heavy-ion collisions with the transport DCM and UrQMD models. The hyperon capture was calculated within the potential and coalescence approaches. We demonstrate that even at the beam energies around and lower than the threshold for producing Lambda hyperons in binary nucleon-nucleon interactions a considerable amount of hypernuclei, including multi-strange ones, can be produced. This is important for preparation of new experiments on hypernuclei in the wide energy range. The uncertainties of the predictions are investigated within the models, and the comparison with the strangeness production measured in experiments is also performed.
S. Okada🇯🇵 · D. A. Bennett🇺🇸 · C. Curceanu🇮🇹 · W. B. Doriese🇺🇸 · J. W. Fowler🇺🇸 · J. Gard🇺🇸 · F. P. Gustafsson🇸🇪 · T. Hashimoto🇯🇵 · R. S. Hayano🇯🇵 · S. Hirenzaki🇯🇵 · J. P. Hays-Wehle🇺🇸 · G. C. Hilton🇺🇸 and 26 other authors
High-resolution pionic-atom x-ray spectroscopy was performed with an x-ray spectrometer based on a 240-pixel array of superconducting transition-edge-sensor (TES) microcalorimeters at the piM1 beam line of the Paul Scherrer Institute. X-rays emitted by pionic carbon via the 4f->3d transition and the parallel 4d->3p transition were observed with a full-width-at-half-maximum energy resolution of 6.8 eV at 6.4 keV. Measured x-ray energies are consistent with calculated electromagnetic values which considered the strong-interaction effect assessed via the Seki-Masutani potential for the 3p energy level, and favor the electronic population of two filled 1s electrons in the K-shell. Absolute energy calibration with an uncertainty of 0.1 eV was demonstrated under a high-rate hadron beam condition of 1.45 MHz. This is the first application of a TES spectrometer to hadronic-atom x-ray spectroscopy and is an important milestone towards next-generation high-resolution kaonic-atom x-ray spectroscopy.
first authorsco-authorsvia INSPIRE