119181282
CONSTRAINING THE SYMMETRY ENERGY FROM THE NEUTRON SKIN THICKNESS OF TIN ISOTOPES
and the calcu-lations have been usually carried out by varying the interaction parameters.A well-known example is the Skyrme-Hartree-Fock (SHF) approach usingnormally 9 interaction parameters and there are more than 120 sets ofSkyrme interaction parameters in the literature.In the present talk, we report our recent work
125427818
Anisotropic flows and dihadron correlations in heavy ion collisions
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.
119164414
Nuclear constraints on non-Newtonian gravity at femtometer scale
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.
118536957
Locating the inner edge of the neutron star crust using terrestrial nuclear laboratory data
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.
119288462
Non-Newtonian gravity in finite nuclei
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.
119184097
Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars
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.
124654178
Extracting the jet transport coefficient from jet quenching in high-energy heavy-ion collisions
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.
119265603
Submillimeter / millimeter observations of the molecular clouds associated with Tycho’s supernova remnant
We have carried out CO J = 2 - 1 and CO J = 3 - 2 observations toward Tycho's supernova remnant (SNR) using the KOSMA 3m-telescope. From these observations, we identified three molecular clouds (MCs) around the SNR. The small cloud in the southwest was discovered for the first time. In the north and east, two MCs (Cloud A and Cloud B) adjacent in space display a bow-shaped morphology, and have broad emission lines, which provide some direct evidences of the SNR-MCs interaction. The MCs are revealed at -69~ -59 km s -1 , coincident with Tycho's SNR. The MCs associated with Tycho's SNR have a mass of ~ 2.13 × 10 3 M ⊙ . Position-velocity diagrams show the two clouds to be adjacent in velocity, which means cloud-cloud collision could occur in this region. The maximum value (0.66 ± 0.10) of the integrated CO line intensity ratio (I CO J =3-2 /I CO J =2-1 ) for the three MCs agrees well with the previous measurement of individual Galactic MCs, implying that the SNR shock drove into the MCs. The two MCs have a line intensity ratio gradient. The distribution of the ratio appears to indicate that the shock propagates from the southwest to the northeast.
27639127
A Tapered Dielectric Structure for Laser Acceleration at Low Energy
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.
119273779
Submillimeter/millimeter observations of the high-mass star forming region IRAS 22506+5944 ∗
The mapping observations of CO J = 2-1, CO J = 3-2, 13 CO J = 2-1 and 13 CO J = 3-2 lines in the direction of IRAS 22506+5944 have been made. The results show that the cores in the J = 2-1 transition lines have a similar morphology to those in the J = 3-2 transition lines. Bipolar molecular outflows are verified. The prior IRAS 22506+5944 observations indicated that two IRAS sources and three H 2 O masers were located close to the peak position of the core. One of the IRAS sources may be the driving source of the outflows. In addition, the H 2 O masers may occur in relatively warm environments. The parameters of the dense core and outflow, obtained by the LTE method, indicate that IRAS 22506+5944 is a high-mass star formation region.
119114895
The open cluster NGC 6823 and possible triggered star formation associated with SNR G59.5+0.1
Aims. We investigate the environment in the vicinity of the supernova remnant (SNR) G59.5+0.1 and identify all the young stellar objects (YSOs) around the SNR, to derive the physical properties, obtain insight into the star-formation history, and determine whether SNR G59.5+0.1 can trigger star formation in this region. Methods. We perform the submillimeter/millimeter observations in CO lines toward the southeast of SNR G59.5+0.1 with the KOSMA 3 m Telescope. High values of the integrated CO line-intensity ratio RICO(3−2)/ICO(2−1) is identified as one good signature of the SNR-MC (molecular cloud) interacting system. To investigate the impact of SNR G59.5+0.1 on the process of star formation, we use GLIMPSE I catalog to select YSOs (including Class I and Class II sources). Results. The CO emission forming an arc-like shape and mid-infrared 8.28 μm emission are coincident with SNR G59.5+0.1, which ‐ ‐