Nuclear Theory·nucl-th

Wednesday·September 18, 2019

10 papers—9 primary·1 cross-listed

01
Constraints in modeling the quasielastic response in inclusive lepton-nucleus scattering
R. González-Jiménez🇪🇸 · M.B. Barbaro🇮🇹 · J.A. Caballero🇪🇸 · T.W. Donnelly🇺🇸 · N. Jachowicz🇧🇪 · G.D. Megias🇪🇸 · K. Niewczas🇧🇪 · A. Nikolakopoulos🇧🇪 · J.M. Udías🇪🇸
We show that the quasielastic (QE) response calculated with the SuSAv2 (superscaling approach) model, that relies on the scaling phenomenon observed in the analysis of (e,e') data and on the relativistic mean-field theory, is very similar to that from a relativistic distorted wave impulse approximation model when only the real part of the optical potentials is employed. The coincidence between the results from these two completely independent approaches, which satisfactorily agree with the inclusive data, reinforces the reliability of the quasielastic predictions stemming from both models and sets constraints for the QE response. We also study the low energy and momentum transfer region of the inclusive response by confronting the results of the relativistic mean-field model with those of the Hartree-Fock continuum random-phase approximation model, which accounts for nuclear long-range correlations. Finally, we present a comparison of our results with the recent JLab (e,e') data for argon, titanium and carbon, finding good agreement with the three data sets.
nucl-thhep-phPRC(2020)·55 citations
02
QCD Kondo excitons
Daiki Suenaga🇨🇳 · Kei Suzuki🇯🇵 · Shigehiro Yasui🇯🇵
The quantum chromodynamics (QCD) Kondo effect is a quantum phenomenon in which heavy quarks ( $c$ , $b$ ) exist as impurity particles in quark matter composed of light quarks ( $u$ , $d$ , $s$ ) at extremely high density. This is analogous to the famous Kondo effect in condensed matter physics. In the present paper, we show theoretically the existence of the "QCD Kondo excitons", i.e., the bound states of light quarks and heavy quarks, as the lowest-excitation modes above the ground state of the quark matter governed by the QCD Kondo effect. These are neutral for color and electric charges, similarly to the Kondo excitons in condensed matter, and they are new type of quasiparticles absent in the normal phase of quark matter. The QCD Kondo excitons have various masses and quantum numbers, i.e., flavors and spin parities (scalar, pseudoscalar, vector, and axialvector). The QCD Kondo excitons lead to the emergence of the neutral currents in transport phenomena, which are measurable in lattice QCD simulations. The study of the QCD Kondo excitons will provide us with understanding of new universal properties shared by quark matter and condensed matter.
nucl-thcond-mat.str-elhep-phPRResearch(2020)·12 citations
03
Structural Properties of Rotating Hybrid Compact Stars with Color-Flavour-Locked Quarks Matter core and its Tidal Deformability
Suman Thakur🇮🇳 · Shashi K Dhiman🇮🇳
We investigate the possible sequels, for the hybrid compact stars consisting of nucleons, hyperons and three flavour color-flavor-locked quarks phase under global neutrality and chemical equilibrium conditions. The hadron equations of state are computed within the framework of energy density functionals based on the relativistic mean field theory by employing two different model parameterizations. The quarks matter phase of equation of state is computed by using Quarks Quasiparticle model derived from a non-relativistic energy density-functional approach. A plausible set of hybrid equations of state for superdense hadron-quarks matter is obtained and, which satisfies the constraints provided by bulk nuclear matter, the observational data of frequencies and maximum Gravitational mass 2 $M_{⊙}$ with their extracted radii, Keplerian limits, secular axisymmetric instability and limits of tidal deformabilities from GW170817 binary neutron stars (BNS) merger. We obtained structural properties of nonrotating and rotating compact stars, the evolutionary sequences with constant baryonic mass star spinning down by electromagnetic and gravitational radiations and, discuss the issues relating to phase transition from hadrons to quarks matter phase. The internal structure of rotating star with observed spin down frequencies, exhibiting shrinkage of soft quarks core of compact stars are discussed for constant baryonic mass. We present the theoretically computed limits of radii for the spin down configurations of hybrid stars corresponding to the recently observed millisecond pulsars. We also present and discuss the calculated results for tidal deformability, $Λ$ and tidal parameters $Λ_{1}$ , $Λ_{2}$ of non spining hybrid star which are consistent with the waveform model analysis of GW170817 BNS.
nucl-thastro-ph.COhep-ph1 citation
04
How the antisymmetrization affects a cluster-cluster interaction: two-cluster systems
V. S. Vasilevsky · Yu. A. Lashko
We study effects of the antisymmetrization on the potential energy of two-cluster systems. The object of the investigation is the lightest nuclei of p-shell with a dominant alpha-cluster channel. For this aim we construct matrix elements of two-cluster potential energy between cluster oscillator functions with and without full antisymmetrization. Eigenvalues and eigenfunctions of the potential energy matrix are studied in detail. Eigenfunctions of the potential energy operator are presented in oscillator, coordinate and momentum spaces. We demonstrate that the Pauli principle affects more strongly the eigenfunctions than the eigenvalues of the matrix and leads to the formation of resonance and trapped states.
nucl-thAnnals Phys.(2020)·0 citations
05
Production of $ϕ (2170)$ and $η (2225)$ in a kaon induced reaction
Xiao-Yun Wang🇨🇳 · Jun He🇨🇳
In this work, we study the production of strange quarkoniums, the $ϕ (2170)$ , also named $Y (2175)$ , and the $η (2225)$ , via a kaon induced reaction on a proton target in an effective Lagrangian approach. The total and differential cross sections of the reactions $K^{-} p \to ϕ (2170) Λ$ and $K^{-} p \to η (2225) Λ$ are calculated by the Reggeized $t$ -channel Born term under an assumption that the $ϕ (2170)$ and $η (2225)$ are $Λ Λ ˉ$ molecular states. At the center of mass energies of about 4.2 GeV, the total cross section for the $ϕ (2170)$ production is predicted to be about 1 $μ$ b. The numerical results indicate that it is feasible to produce the $ϕ (2170)$ via kaon beam scattering at the best energy window near 4.2 GeV. The total cross section for the $η (2225)$ production is smaller than that for the $ϕ (2170)$ production and it may reach an order of the magnitude of 0.1 $μ$ b. The differential cross sections for both reactions at different center of mass energies are also presented. It is found that the Reggeized $t$ channel gives a considerable contribution at forward angles. As the energy increases, the contribution from the $t$ -channel almost concentrates at extreme forward angles. From these theoretical predictions, the relevant experimental research is suggested, which could provide important information to clarify the internal structure and production mechanism of these two strange quarkoniums.
nucl-thhep-phnucl-exEPJA(2019)·14 citations
06
$Υ (1 S)$ transverse momentum spectra through dissociation and regeneration in heavy ion collisions
Juhee Hong🇰🇷 · Su Houng Lee🇰🇷
We calculate the transition between a quarkonium state and an unbound heavy quark-antiquark pair through gluo-dissociation and inelastic parton scattering using a partonic picture that interpolates between the formal limits based on potential nonrelativistic QCD (pNRQCD) at different temperatures. While the thermal width increases with momentum and temperature, the quarkonium regeneration is affected by the heavy quark distribution function which depends on the diffusion constant. By solving the Boltzmann equation with the dissociation and regeneration terms, we investigate the medium modifications of quarkonium momentum spectra. Our numerical results indicate that the $Υ (1 S)$ $R_{AA}$ at high transverse momentum are influenced by the regeneration effects depending on the heavy quark diffusion. In this picture, the published CMS data that show an almost transverse momentum independence can be explained by the interplay between the suppression by dissociation and enhancement by regeneration at low and high transverse momenta, respectively. With the same input, we also calculate the transverse momentum dependence of the $Υ (1 S)$ $v_{2}$ and show that it lies within the limits of the available data.
nucl-thhep-phPLB(2020)·22 citations
07
Can extreme electromagnetic fields accelerate the $α$ decay of nuclei?
Adriana Pálffy · Sergey V. Popruzhenko
The possibility to control the $α$ decay channel of atomic nuclei with electromagnetic fields of extreme intensities envisaged for the near future at multi-petawatt and exawatt laser facilities is investigated theoretically. Using both analytic arguments based on the Wentzel-Kramers-Brillouin approximation and numerical calculations for the imaginary time method applied in the framework of the $α$ decay precluster model, we show that no experimentally detectable modification of the $α$ decay rate can be observed with super-intense lasers at any so-far available wavelength. Comparing our predictions with those reported in several recent publications, where a considerable or even giant laser-induced enhancement of the decay rate has been claimed, we identify there the misuse of a standard approximation.
nucl-thPRL(2020)·39 citations
08
Dynamic description of ternary and quaternary splits of heavy nuclear systems in the deep-inelastic regime
P. Napolitani🇫🇷 · A. Sainte-Marie🇫🇷 · M. Colonna🇮🇹
Colliding heavy nuclear systems in the deep-inelastic regime may undergo partitioning into multiple fragments when fusion can not be achieved. While multiple breakups are common at Fermi energy, they are rather exotic in the deep-inelastic regime, where density, excitation and, in general, transport conditions, are expected to be different. Abundant ternary and quaternary splits have been observed in recent experiments, for instance in symmetric semi-central and semi-peripheral collisions with heavy systems, like $^{197} Au$ + $^{197} Au$ at 15 MeV per nucleon. In these conditions, we undertook a microscopic description of the reaction dynamics. Relying on the full solution of the Boltzmann-Langevin equation implemented in the BLOB approach, we could follow in time the development of instabilities along deformation.
nucl-thPRC(2019)·3 citations
09
Microscopic study of strange hadron productions at the LHC with $s_{N N}$ =2.76 TeV
Purabi Ghosh🇮🇳 · Jajati K. Nayak🇮🇳 · Sushant K. Singh🇮🇳 · Santosh K. Agarwalla🇮🇳
Ratio of the yield of strange hadrons to pions is considered as an important observable in studying the properties of the system produced in relativistic heavy ion collisions. Production of strange hadrons $K, K ˉ, Λ, Σ, Ξ$ and $Ω$ have been evaluated microscopically using rate equations by considering their hadronic interaction cross sections in an expanding medium. The yields obtained from rate equations are normalized with thermal pions and compared with the measurements from Pb-Pb collisions at various multiplicities at LHC energy. The calculation has been done for various initial and freeze out conditions. At 2760 GeV, LHC energy, $Λ, Ξ, Ω$ freeze out close to $T_{C}$ and $K_{s}^{0}$ freezes out little later. But there is a subtle difference in freeze out temperatures of different species which may be distinguishable at lower colliding energies.
nucl-thhep-exhep-phnucl-exPRD(2020)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE