Generic constraints on the relativistic mean-field and Skyrme-Hartree-Fock models from the pure neutron matter equation of state
We study the nuclear symmetry energy S(ρ) and related quantities of nuclear physics and nuclear astrophysics predicted generically by relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) models. We establish a simple prescription for preparing equivalent RMF and SHF parametrizations starting from a minimal set of empirical constraints on symmetric nuclear matter, nuclear binding energy, and charge radii, enforcing equivalence of their Lorenz effective masses, and then using the pure neutron matter (PNM) equation of state obtained from ab initio calculations to optimize the pure isovector parameters in the RMF and SHF models. We find that the resulting RMF and SHF parametrizations give broadly consistent predictions of the symmetry energy J and its slope parameter L at saturation density within a tight range of 2a nd 6 MeV, respectively, but that clear model dependence shows up in the predictions of higher-order symmetry energy parameters, leading to important differences in (a) the slope of the correlation between J and L from the confidence ellipse, (b) the isospin-dependent part of the incompressibility of nuclear matter Kτ , (c) the symmetry energy at suprasaturation densities, and (d) the predicted neutron star radii. The model dependence can lead to about 1–2 km difference in predictions of the neutron star radius given identical predicted values of J and L and symmetric nuclear matter (SNM) saturation properties. Allowing the full freedom in the effective masses in both models leads to constraints of 30 J 31. 5M eV, 35 L 60 MeV, and −330 Kτ −216 MeV for the RMF model as a whole and 30 J 33 MeV, 28 L 65 MeV, and −420 Kτ −325 MeV for the SHF model as a whole. Notably, given PNM constraints, these results place RMF and SHF models as a whole at odds with some constraints on Kτ inferred from giant monopole resonance and neutron skin experimental results.

title: Nuclear constraints on non-Newtonian gravity at femtometer scale
abstract: Effects of the non-Newtonian gravity on properties of finite nuclei are studied by consistently incorporating both the direct and exchange contribution of the Yukawa potential in the Hartree–Fock approach using a well-tested Skyrme force for the strong interaction. It is shown for the first time that the strength of the Yukawa term in the non-Newtonian gravity is limited to log (|α|) < 1.75/[λ(fm)]0.54 + 33.6 within the length scale of λ = 1 − 10 fm in order for the calculated properties of finite nuclei not to be in conflict with accurate experimental data available.

title: Anisotropic flows and dihadron correlations in heavy ion collisions
abstract: Using a multiphase transport model that includes both initial partonic and final hadronic scatterings, we have studied anisotropic flows and dihadron correla tions as functions of pseudorapidity and azimuthal angular differences between trigger and associated particles in heavy ion collisions at LHC. With parameters in the model determined from fitting t he measured multiplicity density of mid-pseudorapidity charged particles in central collis ions and their elliptic flow in mid-central collisions, the calculated higher-order anisotropic flows from the two-particle cumulant method reproduce approximately those measured in experiments. Similar to experimental results, the two-dimensional dihadron correlations at most central collisions show a ridge structure at the near side and a broad structure at the away side. The short- and long-range dihadron azimuthal correlations, corresponding to small and large pseudorapidity differences, respectively, are studied for triggering particles with different transverse mom enta and are found to be qualitatively consistent with experimental results.

title: Non-Newtonian gravity in finite nuclei
abstract: In this talk, we report our recent study of constraining the non-Newtonian gravity at femtometer scale. We incorporate the Yukawa-type non-Newtonian gravitational potential consistently to the Skyrme functional form using the exact treatment for the direct contribution and density-matrix expansion method for the exchange contribution. The effects from the non-Newtonian potential on finite nuclei properties are then studied together with a well-tested Skyrme force. Assuming that the framework without non-Newtonian gravity can explain the binding energies and charge radii of medium to heavy nuclei within 2% error, we set an upper limit for the strength of the non-Newtonian gravitational potential at femtometer scale.

title: Locating the inner edge of the neutron star crust using terrestrial nuclear laboratory data
abstract: Within both dynamical and thermodynamical approaches using the equation of state for neutron-rich nuclear matter constrained by the recent isospin diffusion data from heavy-ion reactions in the same subsaturation density range as the neutron star crust, the density and pressure at the inner edge separating the liquid core from the solid crust of neutron stars are determined to be $0.040 {\mathrm{fm}}^{\ensuremath{-}3}\ensuremath{\leqslant}{\ensuremath{\rho}}_{t}\ensuremath{\leqslant}0.065 {\mathrm{fm}}^{\ensuremath{-}3}$ and 0.01 MeV/${\mathrm{fm}}^{3}\ensuremath{\leqslant}{P}_{t}\ensuremath{\leqslant}0.26$ MeV/${\mathrm{fm}}^{3}$, respectively. These together with the observed minimum crustal fraction of the total moment of inertia allow us to set a new limit for the radius of the Vela pulsar significantly different from the previous estimate. It is further shown that the widely used parabolic approximation to the equation of state of asymmetric nuclear matter leads systematically to significantly higher core-crust transition densities and pressures, especially with stiffer symmetry energy functionals.

title: Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars
abstract: Significant progress has been made in recent years in constraining the density dependence of nuclear symmetry energy using terrestrial nuclear laboratory data. Around and below the nuclear matter saturation density, the experimental constraints start to merge in a relatively narrow region. At supra-saturation densities, there are, however, still large uncertainties. After summarizing the latest experimental constraints on the density dependence of nuclear symmetry energy, we highlight a few recent studies examining imprints of nuclear symmetry energy on the binding energy, energy release during hadron-quark phase transitions as well as the ω-mode frequency and damping time of gravitational wave emission of neutron stars.

title: SUBMILLIMETER ARRAY AND VERY LARGE ARRAY OBSERVATIONS IN THE HYPERCOMPACT H II REGION G35.58-0.03
abstract: The formation of hypercompact (HC) H II regions is an important stage in massive star formation. Spectral line and continuum observations can explore its dynamic conditions. We present high angular resolution observations carried out with the Submillimeter Array (SMA) and the Very Large Array (VLA) toward the HC H II region G35.58-0.03. With the 1.3?mm SMA and 1.3?cm VLA, we detected a total of about 25 transitions of 8 different species and their isotopologues (CO, CH3CN, SO2, CH3CCH, OCS, CS, H, and NH3). G35.58-0.03 consists of an HC H II core with electron temperature ?K, emission measure EM 1.9 ? 109?pc?cm?6, local volume electron density ne = 3.3 ? 105?cm?3, and a same width of radio recombination line FWHM? 43.2?km s?1 for both H30? and H38? at its intrinsic core size ~3714 AU. The H30? line shows evidence of an ionized outflow driving a molecular outflow. Based on the derived Lyman continuum flux, there should be an early-type star equivalent to O6.5 located inside the H II region. From the continuum spectral energy distribution from 3.6?cm, 2.0?cm, 1.3?cm, 1.3?mm and 0.85?mm to 0.45?mm, we distinguished the free-free emission (25% ~ 55%) from the warm dust component (75%?~ 45%) at 1.3?mm. The molecular envelope shows evidence of infall and outflow with an infall rate of 0.05 M ? yr?1 and a mass loss rate of 5.2 ? 10?3 M ? yr?1. The derived momentum (~0.05 M ? km s?1) is consistent between the infalling and outflowing gas per year. It is suggested that the infall is predominant and the envelope mass of dense core is increasing rapidly, but the accretion in the inner part might already be halted.

title: 12CO J=2?1 and 12CO J=3?2 observations toward the high-mass protostellar candidate IRAS 20188+3928
abstract: We have carried out observations of 12 CO J =2–1 and 12 CO J =3–2 toward the high-mass protostellar candidate IRAS 20188+3928. Compared with previous observations, the 12 CO J =2–1 and 12 CO J =3–2 lines both have asymmetric profiles with an absorption dip. The velocity of the absorption dip is ~ 1.0 km s −1 . The spectral shape may be caused by rotation. The velocity-integrated intensity map and position-velocity diagram of the 12 CO J =2–1 line present an obvious bipolar component, further verifying that this region has an outflow motion. This region is also associated with an HII region, an IRAS source, and an H 2 O maser. The H 2 O maser has the velocity of 1.1 km s −1 . Compared with the components of the outflow, we find that the H 2 O maser is not associated with the outflow. Using the large velocity gradient model, we concluded that possible averaged gas densities of the blueshifted lobe and redshifted lobe are 1.0×10 5 cm −3 and 2.0×10 4 cm −3 , while kinetic temperatures are 26.9 K and 52.9 K, respectively. Additionally, the outflow has a higher integrated intensity ratio ( I CO J =3−2 / I CO J =2−1 ).

title: A Tapered Dielectric Structure for Laser Acceleration at Low Energy
abstract: This paper extends the physics of the Micro-Accelerator Platform (MAP), which is in development as an optical structure for laser acceleration of relativistic electrons. The MAP is a resonant, optical-scale, slab-symmetric device that is fabricated from dielectric materials using layer-deposition techniques. For stand-alone applications, low-energy electrons ( ~ 0.3) must be synchronously accelerated to relativistic speeds for injection into the MAP. Even lower energies are desired for other particle species (e.g. protons or muons). In this paper, we present design and simulation studies on a tapered geometry and associated coupling scheme that can produce synchronous acceleration at < 1 within a MAP-like structure.

title: Extracting the jet transport coefficient from jet quenching in high-energy heavy-ion collisions
abstract: Within five different approaches to parton propagation and energy loss in dense matter, a phenomenological study of experimental data on suppression of large $p_T$ single inclusive hadrons in heavy-ion collisions at both RHIC and LHC was carried out. The evolution of bulk medium used in the study for parton propagation was given by 2+1D or 3+1D hydrodynamic models which are also constrained by experimental data on bulk hadron spectra. Values for the jet transport parameter $\hat q$ at the center of the most central heavy-ion collisions are extracted or calculated within each model, with parameters for the medium properties that are constrained by experimental data on the hadron suppression factor $R_{AA}$. For a quark with initial energy of 10 GeV we find that $\hat q\approx 1.2 \pm 0.3$ GeV$^2$/fm at an initial time $\tau_0=0.6$ fm/$c$ in Au+Au collisions at $\sqrt{s}=200$ GeV/n and $\hat q\approx 1.9 \pm 0.7 $ GeV$^2$/fm in Pb+Pb collisions at $\sqrt{s}=2.76 $ TeV/n. Compared to earlier studies, these represent significant convergence on values of the extracted jet transport parameter, reflecting recent advances in theory and the availability of new experiment data from the LHC.

title: Azimuthal jet flavor tomography with CUJET2.0 of nuclear collisions at RHIC and LHC
abstract: A bstractA perturbative QCD based jet tomographic Monte Carlo model, CUJET2.0, is presented to predict jet quenching observables in relativistic heavy ion collisions at RHIC/BNL and LHC/CERN energies. This model generalizes the DGLV theory of flavor dependent radiative energy loss by including multi-scale running strong coupling effects. It generalizes CUJET1.0 by computing jet path integrations though more realistic 2 + 1D transverse and longitudinally expanding viscous hydrodynamical fields contrained by fits to low pT flow data. The CUJET2.0 output depends on three control parameters, (αmax, fE, fM ), corresponding to an assumed upper bound on the vacuum running coupling in the infrared and two chromo-electric and magnetic QGP screening mass scales (fEμ(T ), fMμ(T )) where μ(T ) is the 1-loop Debye mass. We compare numerical results as a function of αmax for pure and deformed HTL dynamically enhanced scattering cases corresponding to (fE = 1, 2, fM = 0) to data of the nuclear modification factor, RAAf(pT, ϕ; s,b$$ \sqrt{s}, b $$) for jet fragment flavors f = π, D, B, e at s$$ \sqrt{s} $$ = 0.2 − 2.76 ATeV c.m. energies per nucleon pair and with impact parameter b = 2.4, 7.5 fm. A χ2 analysis is presented and shows that RAAπ data from RHIC and LHC are consistent with CUJET2.0 at the χ2/d.o.f < 2 level for αmax = 0.23 − 0.30. The corresponding q^$$ \widehat{q} $$(Ejet, T )/T3 effective jet transport coefficient field of this model is computed to facilitate comparison to other jet tomographic models in the literature. The predicted elliptic asymmetry, v2(pT ; s$$ \sqrt{s} $$, b) is, however, found to significantly underestimated relative to RHIC and LHC data. We find the χv22$$ {\chi}_{v_2}^2 $$ analysis shows that v2 is very sensitive to allowing even as little as 10% variations of the path averaged αmax along in and out of reaction plane paths.