Nuclear Theory·nucl-th

Tuesday·September 13, 2016

15 papers—7 primary·8 cross-listed

01
[Submitted on 10 Sept 2016]
Role of correlations on spin-polarized neutron matter
Isaac Vidana · Artur Polls · Victoria Durant
Using the Hellmann--Feynman theorem we analyze the contribution of the different terms of the nucleon-nucleon interaction to the spin symmetry energy of neutron matter. The analysis is performed within the microscopic Brueckner--Hartree--Fock approach using the Argonne V18 realistic potential plus the Urbana IX three-body force. The main contribution to the spin-symmetry energy of neutron matter comes from the S=0 channel, acting only in the non-polarized neutron matter, in particular the $^{1} S_{0}$ and the $^{1} D_{2}$ partial waves. The importance of correlations in spin-polarized neutron matter is estimated by evaluating the kinetic energy difference between the correlated system and the underlying Fermi sea.
Comments:
7 pages, 2 figures. Accepted for publication in Physical Review C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1609.03005 [pdf]
PRC(2016)·10 citations
02
[Submitted on 10 Sept 2016]
Three-body systems in pionless effective field theory
Jared Vanasse
Investigations of three-body nuclear systems using pionless effective field theory ( $EFT_{\neq π}$ ) are reviewed. The history of $EFT_{\neq π}$ in $n d$ and $p d$ scattering is briefly discussed and emphasis put on the use of strict perturbative techniques. In addition renormalization issues appearing in $p d$ scattering are also presented. Bound state calculations are addressed and new perturbative techniques for describing them are highlighted. Three-body breakup observables in $n d$ scattering are also considered and the utility of $EFT_{\neq π}$ for addressing them.
Comments:
27 pages, 27 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1609.03086 [pdf]
IJMPE(2016)·14 citations
03
[Submitted on 11 Sept 2016]
Correlating charge radius with quadrupole deformation and $B (E 2)$ in atomic nuclei
Bao-Hua Sun · Chuan-Ye Liu · Hao-Xin Wang
A very good linear correlation is found between the four-point charge radius relation $δ R_{2 p - 2 n} (Z, N)$ with that of quadrupole deformation data in even-even nuclei. This results in a further improved charge radius relation that holds in a precision of about 5 $\times 1 0^{- 3}$ fm. Such correlations are also seen in global nuclear models, their precisions, however, are not enough to be consistent with the experimental data. The new relation between charge radii and deformation of even-even nuclei can be generalized to the reduced electric quadrupole transition probability $B (E 2)$ between the first $2^{+}$ state and the $0^{+}$ ground state, and the mean lifetime $τ$ of the first 2 $^{+}$ state.
Comments:
6 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1609.03144 [pdf]
PRC(2017)·17 citations
04
[Submitted on 11 Sept 2016]
Second-order perturbation theory for 3He and pd scattering in pionless EFT
Sebastian König🇺🇸
This work implements pionless effective field theory with the two-nucleon system expanded around the unitarity limit at second order perturbation theory. The expansion is found to converge well. All Coulomb effects are treated in perturbation theory, including two-photon contributions at next-to-next-to-leading order. After fixing a three-nucleon force to the 3He binding energy at this order, proton-deuteron scattering in the doublet S-wave channel is calculated for moderate center-of-mass momenta.
Comments:
24 pages, 7 figures, published version
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1609.03163 [pdf]
J.Phys.G(2017)·28 citations
05
[Submitted on 12 Sept 2016]
Gamma Matrix Expansion of the Bethe-Salpeter Equation for Nucleon-Nucleon System
Susumu Kinpara
For the coefficients of the amplitude a set of simultaneous equations is derived in momentum space. By the auxiliary conditions they are equivalent to nonrelativistic equations and suitable for the investigation of two-nucleon system.
Comments:
8 pages
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1609.03294 [pdf]
1 citation
06
[Submitted on 12 Sept 2016]
Elastic scattering, polarization and absorption of relativistic antiprotons on nuclei
A.B. Larionov🇩🇪 · H. Lenske🇩🇪
We perform Glauber model calculations of the antiproton-nucleus elastic and quasielastic scattering and absorption in the beam momentum range $\sim 0.5 \div 10$ GeV/c. A good agreement of our calculations with available LEAR data and with earlier Glauber model studies of the $p ˉ A$ elastic scattering allows us to make predictions at the beam momenta of $\sim 10$ GeV/c, i.e. at the regime of the PANDA experiment at FAIR. The comparison with the proton-nucleus elastic scattering cross sections shows that the diffractive minima are much deeper in the $p ˉ A$ case due to smaller absolute value of the ratio of the real-to-imaginary part of the elementary elastic amplitude. Significant polarization signal for $p ˉ A$ elastic scattering at 10 GeV/c is expected. We have also revealed a strong dependence of the $p ˉ A$ absorption cross section on the slope parameter of the transverse momentum dependence of the elementary $p ˉ N$ amplitude. The $p ˉ A$ optical potential is discussed.
Comments:
36 pages, 14 figures, minor revisions, results unchanged, version accepted in Nucl. Phys. A
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1609.03343 [pdf]
NPA(2017)·12 citations
07
[Submitted on 12 Sept 2016]
Determination of the $η^{3} He$ threshold structure from the low energy $pd \to η^{3} He$ reaction
Ju-Jun Xie🇨🇳 · Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸 · Pawel Moskal🇵🇱 · Magdalena Skurzok🇵🇱 · Colin Wilkin🇬🇧
We analyze the data on cross sections and asymmetries for the $p d (d p) \to η^{3} He$ reaction close to threshold and look for bound states of the $η^{3} He$ system. Rather than parameterizing the scattering matrix, as is usually done, we develop a framework in which the $η^{3} He$ optical potential is the key ingredient, and its strength, together with some production parameters, are fitted to the available experimental data. The relationship of the scattering matrix to the optical potential is established using the Bethe-Salpeter equation and the $η^{3} He$ loop function incorporates the range of the interaction given by the empirical $^{3} He$ density. We find a local Breit Wigner form of the $η^{3}$ He amplitude $T$ below threshold with a clear peak in $∣ T ∣^{2}$ , which corresponds to an $η^{3} He$ binding of about 0.3 MeV and a width of about 3 MeV. By fitting the potential we can also evaluate the $η^{3} He$ scattering length, including its sign, thus resolving the ambiguity in the former analyses.
Comments:
7 pages, 9 figures. Title slightly changed, more considerations added
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1609.03399 [pdf]
PRC(2017)·45 citations
08
[Submitted on 9 Sept 2016] (cross-list from hep-ph)
Hydrodynamic Predictions for Pb+Pb Collisions at 5.02 A TeV
Scott McDonald🇨🇦 · Chun Shen🇨🇦 · Francois Fillion-Gourdeau🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
Predictions and comparisons of hadronic flow observables for Pb+Pb collisions at 2.76 A TeV and 5.02 A TeV are presented using a hydrodynamics + hadronic cascade hybrid approach. Initial conditions are generated via a new formulation of the IP-Glasma model and then evolved using relativistic viscous hydrodynamics and finally fed into transport cascade in the hadronic phase. The results of this work show excellent agreement with the recent charged hadron anisotropic flow measurements from the ALICE collaboration of Pb+Pb collisions at 5.02 A TeV. Event-by-event distributions of charged hadron v n , flow event-plane correlations, and flow factorization breaking ratios are compared with existing measurements at 2.76 A TeV, and are predicted at 5.02 A TeV. Further predictions of identified hadron observables (for both light and multi-strange hadrons), such as p T -spectra and anisotropic flow coefficients, are presented.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1609.02958 [pdf]
PRC(2017)·142 citations
09
[Submitted on 10 Sept 2016] (cross-list from hep-ph)
Numerical magneto-hydrodynamics for relativistic nuclear collisions
Gabriele Inghirami🇩🇪 · Luca Del Zanna🇮🇹 · Andrea Beraudo🇮🇹 · Mohsen Haddadi Moghaddam🇮🇷 · Francesco Becattini🇮🇹 · Marcus Bleicher🇩🇪
We present an improved version of the ECHO-QGP numerical code, which self-consistently includes for the first time the effects of electromagnetic fields within the framework of relativistic magnetohydrodynamics (RMHD). We discuss results of its application in relativistic heavy-ion collisions in the limit of infinite electrical conductivity of the plasma. After reviewing the relevant covariant $3 + 1$ formalisms, we illustrate the implementation of the evolution equations in the code and show the results of several tests aimed at assessing the accuracy and robustness of the implementation. After providing some estimates of the magnetic fields arising in non-central high-energy nuclear collisions, we perform full RMHD simulations of the evolution of the Quark-Gluon Plasma in the presence of electromagnetic fields and discuss the results. In our ideal RMHD setup we find that the magnetic field developing in non-central collisions does not significantly modify the elliptic-flow of the final hadrons. However, since there are uncertainties in the description of the pre-equilibrium phase and also in the properties of the medium, a more extensive survey of the possible initial conditions as well as the inclusion of dissipative effects are indeed necessary to validate this preliminary result.
Comments:
19 pages, 14 figures, vers. 3: final version, with minor changes in the text (introduction and conclusions)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1609.03042 [pdf]
EPJC(2016)·179 citations
10
[Submitted on 11 Sept 2016] (cross-list from hep-ph)
Strongly coupled non-Abelian plasmas in a magnetic field
Renato Critelli🇧🇷
In this dissertation we use the gauge/gravity duality approach to study the dynamics of strongly coupled non-Abelian plasmas. Ultimately, we want to understand the properties of the quark-gluon plasma (QGP), whose scientifc interest by the scientific community escalated exponentially after its discovery in the 2000's through the collision of ultrarelativistic heavy ions. One can enrich the dynamics of the QGP by adding an external field, such as the baryon chemical potential (needed to study the QCD phase diagram), or a magnetic field. In this dissertation, we choose to investigate the magnetic effects. Indeed, there are compelling evidences that strong magnetic fields of the order $e B \sim 10 m_{π}^{2}$ are created in the early stages of ultrarelativistic heavy ion collisions. The chosen observable to scan possible effects of the magnetic field on the QGP was the viscosity, due to the famous result $η / s = 1/4 π$ obtained via holography. In a first approach we use a caricature of the QGP, the $N = 4$ super Yang-Mills plasma to calculate the deviations of the viscosity as we add a magnetic field. We must emphasize, though, that a magnetized plasma has a priori seven viscosity coefficients (five shears and two bulks). In addition, we also study in this same model the anisotropic heavy quark-antiquark potential in the presence of a magnetic field. In the end, we propose a phenomenological holographic QCD-like model, which is built upon the lattice QCD data, to study the thermodynamics and the viscosity of the QGP with an external strong magnetic field.
Comments:
M.Sc. thesis, 205 pages. Based on Refs. [1406.6019], [1409.0556], [1505.07894], and [1605.06061]
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1609.03104 [pdf]
2 citations
11
[Submitted on 11 Sept 2016] (cross-list from hep-ph)
Neutrino potential for neutrinoless double beta decay
Yoritaka Iwata🇯🇵
Neutrino potential for neutrinoless double beta decay is studied with focusing on its statistical property. The statistics provide a gross view of understanding amplitude of constitutional components of the nuclear matrix element.
Comments:
To be published in Nuclear Physics Review (invited talk at 2016 Dalian International Workshop on Nuclear Physics). arXiv admin note: substantial text overlap with arXiv:1701.07894
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1609.03118 [pdf]
Nucl.Phys.Rev.(2017)·2 citations
12
[Submitted on 11 Sept 2016] (cross-list from quant-ph)
Decoherence and determinism in a one-dimensional cloud-chamber model
Jean-Marc Sparenberg🇧🇪 · David Gaspard🇧🇪
The hypothesis by Sparenberg et al. (2013) that the particular linear tracks appearing in the measurement of a spherically-emitting radioactive source in a cloud chamber are determined by the (random) positions of atoms or molecules inside the chamber is further explored in the framework of a recently established one-dimensional model by Carlone et al. (2015). In this model, meshes of localized spins 1/2 play the role of the cloud-chamber atoms and the spherical wave is replaced by a linear superposition of two wave packets moving from the origin to the left and to the right, evolving deterministically according to the Schrödinger equation. We first revisit these results using a time-dependent approach, where the wave packets impinge on a symmetric two-sided detector. We discuss the evolution of the wave function in the configuration space and stress the interest of a non-symmetric detector in a quantum-measurement perspective. Next we use a time-independent approach to study the scattering of a plane wave on a single-sided detector. Preliminary results are obtained, analytically for the single-spin case and numerically for up to 8 spins. They show that the spin-excitation probabilities are sometimes very sensitive to the parameters of the model, which corroborates the idea that the measurement result could be determined by the atom positions. The possible origin of decoherence and entropy increase in future models is finally discussed.
Comments:
Published version in Foundations of Physics. Text modified according to referees' comments
Subjects:
Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
arXiv:
1609.03217 [pdf]
Found.Phys.(2018)·4 citations
13
[Submitted on 12 Sept 2016] (cross-list from hep-ph)
Possible strange hidden-charm pentaquarks from $Σ_{c}^{(*)} D ˉ_{s}^{*}$ and $Ξ_{c}^{(^{'}, *)} D ˉ^{*}$ interactions
Rui Chen🇨🇳 · Jun He🇨🇳 · Xiang Liu🇨🇳
Using the one-boson-exchange model, we investigate the $Λ_{c} D ˉ_{s}^{*}$ , $Σ_{c} D ˉ_{s}^{*}$ , $Σ_{c}^{*} D ˉ_{s}^{*}$ , $Ξ_{c} D ˉ^{*}$ , $Ξ_{c}^{'} D ˉ^{*}$ , and $Ξ_{c}^{*} D ˉ^{*}$ interactions by considering the one-eta-exchange and/or one-pion-exchange contributions. We further predict the existence of hidden-charm molecular pentaquarks. Promising candidates for hidden-charm molecular pentaquarks include a $Ξ_{c}^{'} D ˉ^{*}$ state with $0 (\frac{1}{2}^{-})$ and the $Ξ_{c}^{*} D ˉ^{*}$ states with $0 (\frac{1}{2}^{-})$ and $0 (\frac{3}{2}^{-})$ . Experimental searches for these predicted hidden-charm molecular pentaquarks are an interesting future research topic for experiments like LHCb.
Comments:
8 pages,3 figures. To be published in Chinese Physics C
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1609.03235 [pdf]
CPC(2017)·95 citations
14
[Submitted on 12 Sept 2016] (cross-list from nucl-ex)
Beta spectrum of unique first-forbidden decays as a novel test for fundamental symmetries
Ayala Glick-Magid (HUJI)🇮🇱 · Yonatan Mishnayot (HUJI, WIS, SNRC)🇮🇱 · Ish Mukul (WIS)🇮🇱 · Michael Hass (WIS)🇮🇱 · Guy Ron (HUJI)🇮🇱 · Sergey Vaintraub (SNRC)🇮🇱 · Doron Gazit (HUJI)🇮🇱
Within the Standard Model, the weak interaction of quarks and leptons is characterized by certain symmetry properties, such as maximal breaking of parity and favored helicity. These are related to the $V - A$ structure of the weak interaction. These characteristics were discovered by studying correlations in the directions of the outgoing leptons in nuclear beta decays. These days, correlation measurements in nuclear beta decays are intensively studied to probe for signatures for deviations from these symmetries, which are an indication of Beyond Standard Model physics. We show that the structure of the energy spectrum of emitted electrons in unique first-forbidden $β$ -decays is sensitive to the symmetries of the weak interaction, and thus can be used as a novel probe of physics beyond the standard model. Furthermore, the energy spectrum gives constraints both in the case of right and left coupling of the new symmetry currents. We show that a measurement with modest energy resolution of about 20 keV is expected to lead to new constraints on beyond the standard model interactions with tensor symmetry.
Comments:
Published version
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1609.03268 [pdf]
PLB(2017)·27 citations
15
[Submitted on 12 Sept 2016] (cross-list from hep-ph)
Deuteron structure in the deep inelastic regime
C.A. Garcìa Canal🇦🇷 · T. Tarutina🇦🇷 · V. Vento🇪🇸
We study nuclear effects on the deuteron in the deep inelastic regime using the newest available data analyzing their $Q^{2}$ dependence. We conclude that precise EMC ratios for large $Q^{2}$ (> 30, GeV $^{2}$ ) cannot be obtained without considering these nuclear effects. For this purpose we use a scheme which parametrizes these effects in a simple manner and compare our results with other recent proposals.
Comments:
10 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1609.03408 [pdf]
EPJA(2017)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE