Nuclear Theory·nucl-th

Friday·May 3, 2019

11 papers—4 primary·7 cross-listed

01
[Submitted on 2 May 2019]
Neutrino-induced single-pion production: Kinematics and Cross Section
Raúl González-Jiménez
In the energy range of present and future accelerator-based neutrino-oscillation experiments, single-pion production (SPP) is one of the main contributions to the neutrino-nucleus scattering cross section. For these neutrino energies, ranging from several hundreds of MeV to a few GeV, the SPP on the nucleus is usually described by the reaction in which the incoming lepton couples to one bound nucleon in the nucleus, producing a pion and the knock-out nucleon, along with the residual system and the scattered lepton in the final state. Here, the kinematics and cross section formula for this process are discussed, although the formalism can be applied to other $2 \to 4$ processes.
Comments:
Proceedings of the 20th International Workshop on Neutrinos (NuFACT18), 12-18 August 2018 Blacksburg, Virginia, USA
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1905.00535 [pdf]
PoS(2019)·4 citations
02
[Submitted on 2 May 2019]
Net-proton number fluctuations in the presence of the QCD critical point
Michał Szymański🇵🇱 · Marcus Bluhm🇵🇱 · Krzysztof Redlich🇵🇱 · Chihiro Sasaki🇵🇱
Event-by-event fluctuations of the net-proton number studied in heavy-ion collisions provide an important means in the search for the conjectured critical end point (CP) in the QCD phase diagram. We propose a phenomenological model in which the fluctuations of the chiral critical mode couple to protons and anti-protons. This allows us to study the behavior of the net-proton number fluctuations in the presence of the CP. Calculating the net-proton number cumulants, $C_{n}$ with n=1,2,3,4, along the phenomenological freeze-out line we show that the ratio of variance and mean $C_{2} / C_{1}$ , as well as kurtosis $C_{4} / C_{2}$ resemble qualitative properties observed in data in heavy-ion collisions as a function of beam energy obtained by the STAR Collaboration at RHIC. In particular, the non-monotonic structure of the kurtosis and smooth change of the $C_{2} / C_{1}$ ratio with beam energy could be due to the CP located near the freeze-out line. The skewness, however, exhibits properties that are in contrast to the criticality expected due to the CP. The dependence of our results on the model parameters and the proximity of the chemical freeze-out to the critical point are also discussed.
Comments:
19 pages, 5 figures. Version accepted for publication in Journal of Physics G: Nuclear and Particle Physics
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1905.00667 [pdf]
J.Phys.G(2020)·12 citations
03
[Submitted on 2 May 2019]
Electromagnetic properties of the $d^{*} (2380)$ hexaquark
M. Bashkanov🇬🇧 · D.P. Watts🇬🇧 · A. Pastore🇬🇧
Experiments with intense photon and electron beams have the potential to provide access to nontrivial properties of the recently discovered $d^{*} (2380)$ hexaquark including its size, structure, magnetic moment, quadrupole and octupole deformations. In this paper we investigate the sensitivity of ongoing and planned experiments to various properties of the $d^{*} (2380)$ , employing models based on both constituent quark and pion cloud frameworks. Our calculations indicate that for photoinduced reactions on the deuteron the $d^{*} (2380)$ is predominantly produced from the $D - w a v e$ component of the deuteron. We confirm earlier findings that the intrinsic quadrupole deformation of the $d^{*} (2380)$ should be small. We also demonstrate an ability to extract the $d^{*} (2380)$ magnetic moment and put constrains on the $d^{*} (2380)$ $M 3/ E 2$ ratio.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1905.00713 [pdf]
PRC(2019)·11 citations
04
[Submitted on 2 May 2019]
Nonlocalized Clustering and Evolution of Cluster Structure in Nuclei
Bo Zhou · Yasuro Funaki · Hisashi Horiuchi · Akihiro Tohsaki
We explain various facets of the THSR (Tohsaki-Horiuchi-Schuck-Röpke) wave function. We first discuss the THSR wave function as a wave function of cluster-gas state, since the THSR wave function was originally introduced to elucidate the 3 $α$ -condensate-like character of the Hoyle state ( $0_{2}^{+}$ state) of $^{12}$ C. We briefly review the cluster-model studies of the Hoyle state in 1970's in order to explain how there emerged the idea to assign the $α$ condensate character to the Hoyle state. We then explain that the THSR wave function can describe very well also non-gaslike ordinary cluster states with spatial localization of clusters. This fact means that the dynamical motion of clusters is of nonlocalized nature just as in gas-like states of clusters and the localization of clusters is due to the inter-cluster Pauli principle which is against the close approach of two clusters. The nonlocalized cluster dynamics is formulated by the container model of cluster dynamics. The container model describes gas-like state and non-gaslike states as the solutions of the Hill-Wheeler equation with respect to the size parameter of THSR wave function which is just the size parameter of the container. When we notice that fact that the THSR wave function with the smallest value of size parameter is equivalent to the shell-model wave function, we see that the container model describes the evolution of cluster structure from the ground state with shell-model structure up to the gas-like cluster state via ordinary non-gaslike cluster states. For the description of various cluster structure, more generation of THSR wave function have been introduced and we review some typical examples with their actual applications.
Comments:
71 pages, 54 figures, review paper
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1905.00788 [pdf]
Front.Phys.(Beijing)(2020)·36 citations
05
[Submitted on 29 Apr 2019] (cross-list from hep-lat)
Conformal perturbation theory confronts lattice results in the vicinity of a critical point
Michele Caselle🇮🇹 · Nicodemo Magnoli🇮🇹 · Alessandro Nada🇩🇪 · Marco Panero🇮🇹 · Marcello Scanavino🇮🇹
We study the accuracy and predictive power of conformal perturbation theory by a comparison with lattice results in the neighborhood of the finite-temperature deconfinement transition of SU(2) Yang-Mills theory, assuming that the infrared properties of this non-Abelian gauge theory near criticality can be described by the Ising model. The results of this comparison show that conformal perturbation theory yields quantitatively accurate predictions in a broad temperature range. We discuss the implications of these findings for the description of the critical point (belonging to the same universality class) of another strongly coupled, non-supersymmetric non-Abelian gauge theory: the critical end-point in the phase diagram of QCD at finite temperature and finite quark chemical potential.
Comments:
22 pages, 2 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1904.12749 [pdf]
PRD(2019)·7 citations
06
[Submitted on 2 May 2019] (cross-list from hep-ph)
Investigate the pentaquark resonance in the $N K$ system
Xuejie Liu🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳
A dynamical calculation of pentaquark systems with quark contents $uu dd s ˉ$ is performed in the framework of quark delocalization color screening model with the help of resonating group method. The effective potentials between baryon and meson clusters are given, and the possible bound states or resonances are investigated. The single calculations show that the $N K^{*}$ with $I = 0, J^{P} = \frac{1}{2}^{-}$ , $Δ K^{*}$ with $I = 1, J^{P} = \frac{1}{2}^{-}$ , and $Δ K^{*}$ with $I = 2, J^{P} = \frac{3}{2}^{-}$ are all bound, but they all turns into scattering states by coupling with the corresponding open channels. A possible resonance state $Δ K^{*}$ with $I = 1, J^{P} = \frac{5}{2}^{-}$ is proposed. The mass is around $2110.5$ MeV, and the decay modes are $N K$ in $D$ -wave or $N K π π$ in $P$ -waves.
Comments:
7 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1905.00583 [pdf]
PRC(2019)·6 citations
07
[Submitted on 2 May 2019] (cross-list from hep-ph)
$Ξ (1690)^{-}$ resonance production via $K^{-} p \to K^{+} K^{-} Λ$
Seung-il Nam🇰🇷 · Jung Keun Ahn🇰🇷
In this talk, we investigate $Ξ (1690)^{-}$ production from the $K^{-} p \to K^{+} K^{-} Λ$ reaction wit the effective Lagrangian method and consider the $s$ - and $u$ -channel $Σ/Λ$ ground states and resonances for the $Ξ$ -pole contributions, in addition to the $s$ -channel $Λ$ , $u$ -channel nucleon pole, and $t$ -channel $K^{-}$ -exchange for the $ϕ$ -pole contributions. The $Ξ$ -pole includes $Ξ (1320)$ , $Ξ (1535)$ , $Ξ (1690) (J^{p} = 1/ 2^{-})$ , and $Ξ (1820) (J^{p} = 3/ 2^{-})$ . We compute the Dalitz plot density of $(d^{2} σ / d M_{K^{+} K^{-}} d M_{K^{-} Λ}$ at 4.2 GeV $/ c$ ) and the total cross sections for the $K^{-} p \to K^{+} K^{-} Λ$ . Employing the parameters from the fit, we present the cross sections for the two-body $K^{-} p \to K^{+} Ξ (1690)^{-}$ reaction near the threshold. We also demonstrate that the Dalitz plot analysis for $p_{K^{-}} = 1.915 \sim 2.065$ GeV/c makes us to explore direct information for $Ξ (1690)^{-}$ production, which can be done by future $K^{-}$ beam experiments.
Comments:
5 pages, 3 figures, proceedings for QNP2019
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1905.00666 [pdf]
JPS Conf.Proc.(2019)·2 citations
08
[Submitted on 2 May 2019] (cross-list from gr-qc)
Role of crustal physics in the tidal deformation of a neutron star
Bhaskar Biswas · Rana Nandi · Prasanta Char · Sukanta Bose
In the late inspiral phase, gravitational waves from binary neutron star mergers carry the imprint of the equation of state due to the tidally deformed structure of the components. If the stars contain solid crusts, then their shear modulus can affect the deformability of the star and, thereby, modify the emitted signal. Here, we investigate the effect of realistic equations of state (EOSs) of the crustal matter, with a realistic model for the shear modulus of the stellar crust in a fully general relativistic framework. This allows us to systematically study the deviations that are expected from fluid models. In particular, we use unified EOSs, both relativistic and non-relativistic, in our calculations. We find that realistic EOSs of crusts cause a small correction, of $\sim 1%$ , in the second Love number. This correction will likely be subdominant to the statistical error expected in LIGO-Virgo observations at their respective advanced design sensitivities, but rival that error in third generation detectors. For completeness, we also study the effect of crustal shear on the magnetic-type Love number and find it to be much smaller.
Comments:
26 pages, 10 figures
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1905.00678 [pdf]
PRD(2019)·29 citations
09
[Submitted on 2 May 2019] (cross-list from hep-ph)
Diffractive excitation in $pp$ and $p A$ collisions at high energies
V. P. Goncalves🇧🇷 · R. Palota da Silva🇧🇷 · P. V. R. G. Silva🇧🇷
In this paper we consider the Good - Walker approach for the diffractive excitation and updated the Miettinen -- Pumplin (MP) model for $pp / p ˉ p$ collisions considering the recent LHC data for the total and elastic $pp$ cross sections. The behavior of the total, elastic and diffractive cross sections is analyzed and predictions for the energies of Run 3 of the LHC and those of the Cosmic Rays experiments are derived. Our results demonstrate that the MP model is able to describe the current data and that it implies that the cross section for the diffraction excitation in $pp$ collisions is almost constant in the energy range probed by the LHC and slowly decreases at higher energies. Our results indicate that the Pumplin bound is not reached at the LHC and Cosmic Ray energies. Moreover, the implications of the diffractive excitation in $p A$ collisions is discussed. In particular, the MP model, constrained by the $pp$ data, is used to derive the main quantities present in the treatment of the diffractive excitation in $p A$ collisions. Predictions for the total, elastic and diffractive $p A$ cross sections are presented considering different nuclei. We demonstrate that the effect of fluctuations decreases at larger energies and heavier nuclei. The energy dependence of the diffractive excitation cross section in $p A$ collisions is estimated for different nuclei and compared with the predictions for the proton dissociation induced by photon interactions.
Comments:
11 pages, 5 figures, 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1905.00806 [pdf]
PRD(2019)·10 citations
10
[Submitted on 2 May 2019] (cross-list from hep-ph)
Equation of state for hot QCD and compact stars from a mean field approach
Anton Motornenko🇩🇪 · Jan Steinheimer🇩🇪 · Volodymyr Vovchenko🇩🇪 · Stefan Schramm🇩🇪 · Horst Stoecker🇩🇪
The thermodynamic properties of high temperature and high density QCD-matter are explored within the Chiral SU(3)-flavor parity-doublet Polyakov-loop quark-hadron mean-field model, CMF. The quark sector of the CMF model is tuned to describe the $μ_{B} = 0$ thermodynamics data of lattice QCD. The resulting lines of constant physical variables as well as the baryon number susceptibilities are studied in some detail in the temperature/chemical potential plane. The CMF model predicts three consecutive transitions, the nuclear first-order liquid-vapor phase transition, chiral symmetry restoration, and the cross-over transition to a quark-dominated phase. All three phenomena are cross-over, for most of the $T - μ_{B}$ -plane. The deviations from the free ideal hadron gas baseline at $μ_{B} = 0$ and $T \approx 100 - 200$ MeV can be attributed to remnants of the liquid-vapor first order phase transition in nuclear matter. The chiral crossing transition determines the baryon fluctuations at much higher $μ_{B} \approx 1.5$ GeV, and at even higher baryon densities $μ_{B} \approx 2.4$ GeV, the behavior of fluctuations is controlled by the deconfinement cross-over. The CMF model also describe well the static properties of high $μ_{B}$ neutron stars as well as the new neutron star merger observations. The effective EoS presented here describes simultaneously lattice QCD results at $μ_{B} = 0$ , as well as observed physical phenomena (nuclear matter and neutron star matter) at $T ≅ 0$ and high densities, $μ_{B} > 1$ GeV.
Comments:
13 pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1905.00866 [pdf]
PRC(2020)·118 citations
11
[Submitted on 2 May 2019] (cross-list from hep-ph)
Dark matter and bubble nucleation in old neutron stars
A. Herrero🇪🇸 · M. A. Pérez-García🇪🇸 · J. Silk🇫🇷 · C. Albertus🇪🇸
We study the probability for nucleation of quark matter droplets in the dense cold cores of old neutron stars induced by the presence of a self-annihilating dark matter component, $χ$ . Using a parameterized form of the equation of state for hadronic and quark phases of ordinary matter, we explore the thermodynamic conditions under which droplet formation is facilitated by the energy injection from $χ$ self-annihilations. We obtain the droplet nucleation time as a function of the dark matter candidate mass, $m_{χ}$ . We discuss further observational consequences.
Comments:
9 pages, 3 figures. Accepted in Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1905.00893 [pdf]
PRD(2019)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE