Nuclear Theory·nucl-th

Wednesday·December 13, 2017

8 papers—5 primary·3 cross-listed

01
Jet-medium interaction and the Gubser flow
Li Yan🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
We study the effects of expansion and viscous corrections on the hydrodynamical medium response to a high energy jet parton. More specifically, using a semi-analytical Gubser solution to relativistic fluid dynamics, modifications to the formed Mach cone, diffusive wake, and the momentum flow of the medium response along and perpendicular to the jet particle, are analyzed mode-by-mode. This should provide intuition and guidance for analyses of the experimentally measured jet sub-structure in heavy-ion collisions.
nucl-thhep-phnucl-exPoS(2018)·2 citations
02
A new scheme for heavy nuclei: proxy-SU(3)
D. Bonatsos · R. F. Casten · A. Martinou · I. E. Assimakis · N. Minkov · S. Sarantopoulou · R. B. Cakirli · K. Blaum
The SU(3) symmetry realized by J. P. Elliott in the sd nuclear shell is destroyed in heavier shells by the strong spin-orbit interaction. However, the SU(3) symmetry has been used for the description of heavy nuclei in terms of bosons in the framework of the Interacting Boson Approximation, as well as in terms of fermions using the pseudo-SU(3) approximation. We introduce a new fermionic approximation, called the proxy-SU(3), and we discuss how some of its novel predictions come out as a consequence of the short range of the nucleon-nucleon interaction and the Pauli principle.
nucl-thAdv.Nucl.Phys.(2017)·5 citations
03
Parameter-independent predictions for nuclear shapes and B(E2) transition rates in the proxy-SU(3) model
A. Martinou · S. Peroulis · D. Bonatsos · I. E. Assimakis · S. Sarantopoulou · N. Minkov · R. B. Cakirli · R. F. Casten · K. Blaum
Using a new approximate analytic parameter-free proxy-SU(3) scheme, we make predictions of shape observables for actinides and superheavy elements, namely beta and gamma deformation variables, and compare these with predictions by relativistic and non-relativistic mean-field theories. Furthermore, we make predictions for B(E2) transition rates of deformed nuclei and compare these with existing data and predictions of other theoretical approaches.
nucl-thAdv.Nucl.Phys.(2017)·1 citation
04
Phenomenological Equation of State of Strongly Interacting Matter with First-Order Phase Transitions and Critical Points
Stefan Typel🇩🇪 · David Blaschke🇵🇱
An extension of the relativistic density functional approach to the equation of state for strongly interacting matter is suggested which generalizes a recently developed modified excluded-volume mechanism to the case of temperature and density dependent available-volume fractions. A parametrisation of this dependence is presented for which at low temperatures and suprasaturation densities a first-order phase transition is obtained. It changes for increasing temperatures to a crossover transition via a critical endpoint. This provides a benchmark case for studies of the role of such a point in hydrodynamic simulations of ultrarelativistic heavy-ion collisions. The approach is thermodynamically consistent and extendable to finite isospin asymmetries that are relevant for simulations of neutron stars, their mergers and core-collapse supernova explosions.
nucl-thUniverse(2018)·13 citations
05
Aspects of Shape Coexistence in the Geometric Collective Model of Nuclei
P. E. Georgoudis · A. Leviatan
We examine the coexistence of spherical and $γ$ -unstable deformed nuclear shapes, described by an SO(5)-invariant Bohr Hamiltonian, along the critical-line. Calculations are performed in the Algebraic Collective Model by introducing two separate bases, optimized to accommodate simultaneously different forms of dynamics. We demonstrate the need to modify the $β$ -dependence of the moments of inertia, in order to obtain an adequate description of such shape-coexistence.
nucl-thJ.Phys.Conf.Ser.(2018)·4 citations
06
Strangeness Production in low energy Heavy Ion Collisions via Hagedorn Resonances
K. Gallmeister🇩🇪 · M. Beitel🇩🇪 · C. Greiner🇩🇪
A novel, unorthodox picture of the dynamics of heavy ion collisions is developed using the concept of Hagedorn states. A prescription of the bootstrap of Hagedorn states respecting the conserved quantum numbers baryon number B, strangeness S, isospin I is implememted into the GiBUU transport model. Using a strangeness saturation suppression factor suitable for nucleon-nucleon-collisions, recent experimental data for the strangeness production by the HADES collaboration in Au+Au and Ar+KCl is reasonable well described. The experimental observed exponential slopes of the energy distributions are nicely reproduced. Thus, a dynamical model using Hagedorn resonance states, supplemented by a strangeness saturation suppression factor, is able to explain essential features (multiplicities, exponential slope) of experimental data for strangeness production in nucleus-nucleus collisions close to threshold.
↳ hep-phhep-exnucl-thPRC(2018)·13 citations
07
World-line formulation of chiral kinetic theory in topological background gauge fields
Niklas Mueller🇺🇸 · Raju Venugopalan🇺🇸
In heavy-ion collisions, an interesting question of phenomenological relevance is how the chiral imbalance generated at early times persists through a fluctuating background of sphalerons in addition to other "non-anomalous" interactions with the QGP. To address this question, we construct a relativistic chiral kinetic theory using the world-line formulation of quantum field theory. We outline how Berry's phase arises in this framework, and how its effects can be clearly distinguished from those arising from the chiral anomaly. We further outline how this framework can be matched to classical statistical simulations at early times and to anomalous chiral hydrodynamics at late times.
↳ hep-phhep-thnucl-thPoS(2018)·4 citations
08
A Subleading Power Operator Basis for the Scalar Quark Current
Cyuan-Han Chang🇺🇸 · Iain W. Stewart🇺🇸 · Gherardo Vita🇺🇸
Factorization theorems play a crucial role in our understanding of the strong interaction. For collider processes they are typically formulated at leading power and much less is known about power corrections in the $λ ≪ 1$ expansion. Here we present a complete basis of power suppressed operators for a scalar quark current at $O (λ^{2})$ in the amplitude level power expansion in the Soft Collinear Effective Theory, demonstrating that helicity selection rules significantly simplify the construction. This basis applies for the production of any color singlet scalar in $q q ˉ$ annihilation (such as $b b ˉ \to H$ ). We also classify all operators which contribute to the cross section at $O (λ^{2})$ and perform matching calculations to determine their tree level Wilson coefficients. These results can be exploited to study power corrections in both resummed and fixed order perturbation theory, and for analyzing the factorization properties of gauge theory amplitudes and cross sections at subleading power.
↳ hep-phnucl-thJHEP(2018)·43 citations

Affiliations

first authorsco-authorsvia INSPIRE