Nuclear Theory·nucl-th

Thursday·September 5, 2019

8 papers—6 primary·2 cross-listed

01
Nuclear structure and reaction with quantum shape fluctuation
Takashi Nakatsukasa · Yu Kashiwaba · Fang Ni · Kouhei Washiyama · Kai Wen · Nobuo Hinohara
We present recent results in theoretical studies on nuclear structure and reaction beyond mean field, using the adiabatic self-consistent collective coordinate method and its extension. We also present new results with the finite-temperature Hartree-Fock-Bogoliubov calculation with the three-dimensional-coordinate-space representation.
nucl-thJPS Conf.Proc.(2020)·0 citations
02
Gamow-Teller transition strengths for selected $f p$ shell nuclei
Vikas Kumar · Praveen C. Srivastava · Anil Kumar
We have reported a systematic shell model description of the experimental Gamow-Teller transition strength for $^{44}$ Sc $\to$ $^{44}$ Ca, $^{45}$ Ti $\to$ $^{45}$ Sc, $^{48}$ Ti $\to$ $^{48}$ V, $^{66}$ Co $\to$ $^{66}$ Ni, and $^{66}$ Fe $\to$ $^{66}$ Co transitions using KB3G and GXPF1A interactions for $f p$ model space. In order to see the importance of higher orbital for $^{66}$ Co $\to$ $^{66}$ Ni and $^{66}$ Fe $\to$ $^{66}$ Co transitions, we have reported the shell model results with $f p g_{9/2}$ space using GXPF1Br+ $V_{M U}$ interaction. We have obtained the qualitative agreement for the individual transitions, while the calculated summed transition strengths closely reproduce the observed ones.
nucl-thActa Phys.Polon.B(2020)·2 citations
03
Longitudinal correlations from fluctuating strings in Pb-Pb, p-Pb, and p-p collisions
Martin Rohrmoser🇵🇱 · Wojciech Broniowski🇵🇱
In a framework of a semi-analytic model with longitudinally extended strings of fluctuating end-points, we demonstrate that the rapidity spectra and two-particle correlations in collisions of Pb-Pb, p-Pb, and p-p at the energies of the Large Hadron Collider can be universally reproduced. In our approach, the strings are pulled by wounded constituents appearing in the Glauber modeling at the partonic level. The obtained rapidity profile for the emission of hadrons from a string yields bounds for the distributions of the end-point fluctuations. Then, limits for the two-particle-correlations in pseudorapidity can be obtained. Our results are favorably compared to recent experimental data from the ATLAS Collaboration.
nucl-thPRC(2020)·8 citations
04
On the role of the Vacuum Energy in the Thermodynamics of Neutron Matter
J.P.W. Diener🇧🇼 · F.G. Scholtz🇿🇦
The only way neutron matter can couple to the electromagnetic field is through an anomalous coupling, which plays an important role in the thermodynamics of pure neutron matter. Such theories are, however, perturbatively non-renormalisable, which presents a difficulty in terms of the unambiguous treatment of the divergencies. Here we show that despite this, an unambiguous expression can be obtained for the vacuum energy contribution to the grand canonical potential in the case of a constant magnetic field. We find that this contribution is quite small, which justifies the no-sea approximation usually made. We also discuss the density and temperature dependence of the full grand canonical potential.
nucl-thPRC(2020)·5 citations
05
A time-dependent Hartree-Fock study of triple-alpha dynamics
P. D. Stevenson · J. L. Willerton
Time-dependent Hartree-Fock calculations have been performed for fusion reactions of He-4 + He-4 -> Be*-8, followed by He-4 + Be*-8 . Depending on the orientation of the initial state, a linear chain vibrational state or a triangular vibration is found in 12C, with transitions between these states observed. The vibrations of the linear chain state and the triangular state occur at ~9 and 4 MeV respectively.
nucl-thSciPost Phys.Proc.(2020)·3 citations
06
Manifestations of SU(3) symmetry in heavy deformed nuclei
D. Bonatsos · A. Martinou · I.E. Assimakis · S. Sarantopoulou · S. Peroulis · N. Minkov
The rapid increase of computational power over the last several years has allowed detailed microscopic investigations of the structure of many nuclei in terms of Relativistic Mean Field theories as well as in the framework of the no-core Shell Model. In heavy deformed nuclei, in which microscopic calculations remain a challenge, algebraic models based on the SU(3) symmetry offer specific predictions, parameter-independent in several cases, directly comparable to experimental data. Two different approximate models for heavy deformed nuclei based on the SU(3) symmetry, the pseudo-SU(3) and the proxy-SU(3) schemes will be discussed and the compatibility between their predictions for the nuclear deformation parameters will be shown. In particular, the dominance of prolate over oblate shapes in the ground states of even-even nuclei and the prolate to oblate shape phase transition occurring in heavy rare earths will be considered.
nucl-thNucl.Theor.(2019)·0 citations
07
A Particle Emitting Source From an Accelerating, Perturbative Solution of Relativistic Hydrodynamics
Bálint Kurgyis🇭🇺 · Máté Csanád🇭🇺
The quark gluon plasma is formed in heavy-ion collisions, and it can be described by solutions of relativistic hydrodynamics. In this paper we utilize perturbative hydrodynamics, where we study first order perturbations on top of a known solution. We investigate the perturbations on top of the Hubble flow. From this perturbative solution we can give the form of the particle emitting source and calculate observables of heavy-ion collisions. We describe the source function and the single-particle momentum spectra for a spherically symmetric solution.
↳ hep-thnucl-thUniverse(2019)·0 citations
08
Chiral Waves on the Fermi-Dirac Sea: Quantum Superfluidity and the Axial Anomaly
Emil Mottola🇺🇸 · Andrey V. Sadofyev🇺🇸
We show that as a result of the axial anomaly, massless fermions at zero temperature define a relativistic quantum superfluid. The anomaly pole implies the existence of a gapless Chiral Density Wave (CDW), i.e. an axion-like acoustic mode of an irrotational and dissipationless Hamiltonian perfect fluid, that is a correlated fermion/anti-fermion pair excitation of the Fermi-Dirac sea. In $D = 2$ dimensions the chiral superfluid effective action coincides with that of the Schwinger model as $e \to 0$ , and the CDW acoustic mode is precisely the Schwinger boson. Since this identity holds also at zero chiral chemical potential, the Dirac vacuum itself may be viewed as a quantum superfluid state. The CDW collective boson is a $U (1)$ chiral phase field, which is gapless as a result of a novel, non-linear realization of Goldstone's theorem, extended to this case of symmetry breaking by an anomaly. A new local form of the axial anomaly bosonic effective action in any $D$ even spacetime is given, consistent with superfluidity, and its quantization is shown to be required by the anomalous Schwinger terms in fermion current commutators. In QED $_{4}$ this collective Goldstone mode appears as a massless pole in the axial anomaly triangle diagram, and is responsible for the macroscopic non-dissipative currents of the Chiral Magnetic and Chiral Separation Effects, as well as the Anomalous Hall Effect. In a constant uniform magnetic field an exact dimensional reduction from $D = 4$ to $D = 2$ occurs and the collective $e^{+} e^{-}$ CDW chiral pair excitation propagating along the magnetic field direction is a Chiral Magnetic Wave, which acquires a mass gap $M^{2} = e^{3} B /2 π^{2}$ . Possible realizations and tests of the theory of collective bosonic excitations due to the anomaly in Dirac/Weyl materials are briefly discussed.
↳ hep-thnucl-thNPB(2021)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE