Nuclear Theory·nucl-th

Wednesday·May 2, 2018

9 papers—5 primary·4 cross-listed

01
Momentum space treatment of inclusive neutrino scattering off the deuteron and trinucleons
J.Golak🇵🇱 · R.Skibinski🇵🇱 · K.Topolnicki🇵🇱 · H.Witala🇵🇱 · A.Grassi🇵🇱 · H.Kamada🇯🇵 · L.E.Marcucci🇮🇹
The $ν ˉ_{e} +^{2} H \to e^{+} + n + n$ , $ν_{e} +^{2} H \to e^{-} + p + p$ , $ν ˉ_{l} +^{2} H \to ν ˉ_{l} +^{2} H$ , $ν_{l} +^{2} H \to ν_{l} +^{2} H$ , $ν ˉ_{l} +^{2} H \to ν ˉ_{l} + p + n$ , $ν_{l} +^{2} H \to ν_{l} + p + n$ , $ν ˉ_{e} +^{3} He \to e^{+} +^{3} H$ , $ν ˉ_{l} +^{3} He \to ν ˉ_{l} +^{3} He$ , $ν_{l} +^{3} He \to ν_{l} +^{3} He$ , $ν ˉ_{l} +^{3} H \to ν ˉ_{l} +^{3} H$ , $ν_{l} +^{3} H \to ν_{l} +^{3} H$ , $ν ˉ_{e} +^{3} He \to e^{+} + n + d$ , $ν ˉ_{e} +^{3} He \to e^{+} + n + n + p$ , $ν ˉ_{l} +^{3} He \to ν ˉ_{l} + p + d$ , $ν ˉ_{l} +^{3} He \to ν ˉ_{l} + p + p + n$ , $ν_{l} +^{3} H \to ν_{l} + n + d$ and $ν_{l} +^{3} H \to ν_{l} + n + n + p$ reactions ( $l = e, μ, τ$ ) are studied consistently in momentum space for (anti)neutrino energies up to 300 MeV. For most of these processes we provide predictions for the total cross sections and in the case of the (anti)neutrino- $^{3}$ He and (anti)neutrino- $^{3}$ H inelastic scattering we compute examples of essential response functions, using the AV18 nucleon-nucleon potential and a single-nucleon weak current operator. For the reactions with the deuteron we study relativistic effects in the final state kinematics and compare two-nucleon scattering states obtained in momentum and coordinate spaces. Our results from momentum space are compared with the theoretical predictions by G.Shen et al., Phys. Rev. C 86, 035503 (2012). The observed disagreement can be attributed to the differences in kinematics and in the weak current operator.
nucl-thPRC(2018)·14 citations
02
Quantum dissipation of a heavy quark from a nonlinear stochastic Schrödinger equation
Yukinao Akamatsu🇯🇵 · Masayuki Asakawa🇯🇵 · Shiori Kajimoto🇯🇵 · Alexander Rothkopf🇩🇪
We study the open system dynamics of a heavy quark in the quark-gluon plasma using a Lindblad master equation. Applying the quantum state diffusion approach by Gisin and Percival, we derive and numerically solve a nonlinear stochastic Schrödinger equation for wave functions, which is equivalent to the Lindblad master equation for the density matrix. From our numerical analysis in one spatial dimension, it is shown that the density matrix relaxes to the Boltzmann distribution in various setups (with and without external potentials), independently of the initial conditions. We also confirm that quantum dissipation plays an essential role not only in the long-time behavior of the heavy quark but also at early times if the heavy quark initial state is localized and quantum decoherence is ineffective.
nucl-thhep-phquant-phJHEP(2018)·51 citations
03
Tidal Deformability of Neutron Stars with Realistic Nuclear Energy Density Functionals
Young-Min Kim🇰🇷 · Yeunhwan Lim🇺🇸 · Kyujin Kwak🇰🇷 · Chang Ho Hyun🇰🇷 · Chang-Hwan Lee🇰🇷
We investigate the constraints on the mass and radius of neutron stars by considering the tidal deformability in the merge of neutron star binaries. In order to extract the most reliable range of uncertainty from theory, we employ models based upon the Skyrme force and density functional theory and select models that are consistent with empirical data of finite nuclei, measured properties of nuclear matter around the saturation density, and observation of the maximum mass of neutron stars. From the selected models, we calculate the Love number $k_{2}$ , dimensionless tidal deformability $Λ$ , and mass-weighted deformability $Λ ~$ in the binary system. We find that all the models considered in this work give $Λ ~$ less than 800 which is the upper limit obtained from the measurement of GW170817. However, the model dependence of tidal deformability is manifest such that our results on the tidal deformability exhibit critical sensitivity to the size of neutron stars.
nucl-thPRC(2018)·24 citations
04
O(6) algebraic theory of three nonrelativistic quarks bound by spin-independent interactions
V. Dmitrašinović🇷🇸 · Igor Salom🇷🇸
We apply the newly developed theory of permutation-symmetric O(6) hyperspherical harmonics to the quantum-mechanical problem of three non-relativistic quarks confined by a spin-independent 3-quark potential. We use our previously derived results to reduce the three-body Schrödinger equation to a set of coupled ordinary differential equations in the hyper-radius $R$ with coupling coefficients expressed entirely in terms of (i) a few interaction-dependent O(6) expansion coefficients and (ii) O(6) hyperspherical harmonics matrix elements, that have been evaluated in our previous paper. This system of equations allows a solution to the eigenvalue problem with homogeneous 3-quark potentials, which class includes a number of standard Ansätze for the confining potentials, such as the Y- and $Δ$ -string ones. We present analytic formulae for the $K = 2, 3, 4, 5$ shell states' eigen-energies in homogeneous three-body potentials, which formulae we then apply to the Y- and $Δ$ -string, as well as the logarithmic confining potentials. We also present numerical results for power-law pair-wise potentials with the exponent ranging between -1 and +2. In the process we resolve the 25 year-old Taxil and Richard vs. Bowler et al. controversy regarding the ordering of states in the $K = 3$ shell, in favor of the former. Finally, we show the first clear difference between the spectra of $Δ$ - and Y-string potentials, which appears in $K \geq 3$ shells. Our results are generally valid, not just for confining potentials, but also for many momentum-independent permutation-symmetric homogenous potentials, that need not be pairwise sums of two-body terms. The potentials that can be treated in this way must be square-integrable under the O(6) hyperangular integral, however, which class does not include the Dirac $δ$ -function.
nucl-thPRD(2018)·5 citations
05
Electric dipole moment of $^{199}$ Hg atom from P, CP-odd electron-nucleon interaction
Kota Yanase🇯🇵 · Naotaka Yoshinaga🇯🇵 · Koji Higashiyama🇯🇵 · Nodoka Yamanaka🇫🇷
We calculate the effect of the P, CP-odd electron-nucleon interaction on the electric dipole moment of the $^{199}$ Hg atom by evaluating the nuclear spin matrix elements in terms of the nuclear shell model. It is found that the neutron spin matrix element of the $^{199}$ Hg nucleus is $⟨ Ψ∣ σ_{n z} ∣Ψ ⟩ \approx - 0.4$ with a dominant configuration of $p_{1/2}$ orbital neutron. We also derive constraints on the CP phases of Higgs-doublet models, supersymmetric models, and leptoquark models from the latest experimental limit $∣ d_{Hg} ∣ < 7.4 \times 1 0^{- 30} e$ cm.
nucl-thhep-exhep-phphysics.atom-phPRD(2019)·41 citations
06
Freeze-out temperature from net-Kaon fluctuations at RHIC
R. Bellwied🇺🇸 · J. Noronha-Hostler🇺🇸 · P. Parotto🇺🇸 · I. Portillo Vazquez🇺🇸 · C. Ratti🇺🇸 · J. M. Stafford🇺🇸
We compare the mean-over-variance ratio of the net-kaon distribution calculated within a state-of-the-art hadron resonance gas model to the latest experimental data from the Beam Energy Scan at RHIC by the STAR collaboration. Our analysis indicates that it is not possible to reproduce the experimental results using the freeze-out parameters from the existing combined fit of net-proton and net-electric charge mean-over-variance. The strange mesons need about 10-15 MeV higher temperatures than the light hadrons at the highest collision energies. In view of the future $Λ$ fluctuation measurements, we predict the $Λ$ variance-over-mean and skewness-times-variance at the light and strange chemical freeze-out parameters. We observe that the $Λ$ fluctuations are sensitive to the difference in the freeze-out temperatures established in this analysis. Our results have implications for other phenomenological models in the field of relativistic heavy ion collisions.
↳ hep-phnucl-thPRC(2019)·69 citations
07
Spin Polarized Non-Relativistic Fermions in 1+1 Dimensions
Andrei Alexandru🇺🇸 · Paulo F. Bedaque🇺🇸 · Neill C. Warrington🇺🇸
We study by Monte Carlo methods the thermodynamics of a spin polarized gas of non-relativistic fermions in 1+1 dimensions. The main result of this work is that our action suffers no significant sign problem for any spin polarization in the region relevant for dilute degenerate fermi gases. This lack of sign problem allows us to study attractive spin polarized fermions non-perturbatively at spin polarizations not previously explored. For some parameters values we verify results previously obtained by methods which include an uncontrolled step like complex Langevin and/or analytical continuation from imaginary chemical potential. For others, larger values of the polarization, we deviate from these previous results.
↳ hep-latcond-mat.quant-gasnucl-thPRD(2018)·20 citations
08
A general procedure for detector-response correction of higher order cumulants
Toshihiro Nonaka🇨🇳 · Masakiyo Kitazawa🇯🇵 · ShinIchi Esumi🇯🇵
We propose a general procedure for the detector-response correction (including efficiency correction) of higher order cumulants observed by the event-by-event analysis in heavy-ion collisions. This method makes use of the moments of the response matrix characterizing the property of a detector, and is applicable to a wide variety of response matrices such as those having non-binomial responses and including the effects of ghost tracks. A procedure to carry out the detector-response correction of realistic detectors is discussed. In test analyses, we show that this method can successfully re- construct the cumulants of true distribution for various response matrices including the one having multiplicity-dependent efficiency.
↳ physics.data-anhep-phnucl-exnucl-thNucl.Instrum.Meth.A(2018)·25 citations
09
Modeling magnetic neutron stars: a short overview
R.O. Gomes🇩🇪 · S. Schramm🇩🇪 · V. Dexheimer🇺🇸
Neutron stars are the endpoint of the life of intermediate mass stars and posses in their cores matter in the most extreme conditions in the universe. Besides their extremes of temperature (found in proto-neutron stars) and densities, typical neutron star' magnetic fields can easily reach trillions of times higher the one of the Sun. Among these stars, about $10%$ are denominated \emph{magnetars} which possess even stronger surface magnetic fields of up to $1 0^{15} - 1 0^{16} G$ . In this conference proceeding, we present a short review of the history and current literature regarding the modeling of magnetic neutron stars. Our goal is to present the results regarding the introduction of magnetic fields in the equation of state of matter using Relativistic Mean Field models (RMF models) and in the solution of Einstein's equations coupled to the Maxwell's equations in order to generate a consistent calculation of magnetic stars structure. We discuss how equation of state modeling affects mass, radius, deformation, composition and magnetic field distribution in stars and also what are the open questions in this field of research.
↳ astro-ph.HEnucl-th3 citations

Affiliations

first authorsco-authorsvia INSPIRE