Nuclear Theory·nucl-th
10 papers—5 primary·5 cross-listed
[Submitted on 24 Oct 2017]
Glasma Flux Tubes, Mono Jets with squeeze out flow around them plus the Chiral Magnetic Effect(CME) are physical phenomenon that generate two particle correlation with respect to the reaction plane in mid-central 20\% to 30\% Au-Au collision = 200.0 GeV measured at RHIC.
[Submitted on 25 Oct 2017]
A. Márquez Romero · J. Dobaczewski · A. Pastore
The long standing problem of neutron-proton pairing correlations is revisited by employing the Hartree-Fock-Bogoliubov formalism with neutron-proton mixing in both the particle-hole and particle-hole channels. We compare numerical calculations performed within this method with an exact pairing model based on the algebra. The neutron-proton mixing is included in our calculations by performing rotations in the isospin space using the isocranking technique.
[Submitted on 25 Oct 2017]
E.E. Saperstein · M. Baldo · S.S. Pankratov · S.V. Tolokonnikov
A method to evaluate the particle-phonon coupling (PC) corrections to the single-particle energies in semi-magic nuclei, based on a direct solving the Dyson equation with PC corrected mass operator, is used for finding the odd-even mass difference between 18 even Pb isotopes and their odd-proton neighbors. The Fayans energy density functional (EDF) DF3-a is used which gives rather high accuracy of the predictions for these mass differences already on the mean-field level, with the average deviation from the existing experimental data equal to 0.389 MeV. It is only a bit worse than the corresponding value of 0.333 MeV for the Skyrme EDF HFB-17 which belongs to a family of Skyrme EDFs with the highest overall accuracy in describing the nuclear masses. Account for the PC corrections induced by the low-laying phonons and significantly diminishes the deviation of the theory from the data till 0.218 MeV.
[Submitted on 25 Oct 2017]
A. Motornenko🇩🇪 · L. Bravina🇳🇴 · M. I. Gorenstein🇺🇦 · A. G. Magner🇺🇦 · E. Zabrodin🇳🇴
Properties of equilibrated nucleon system are studied within the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport model. The UrQMD calculations are done within a finite box with periodic boundary conditions. The system achieves thermal equilibrium due to nucleon-nucleon elastic scattering. For the UrQMD equilibrium state, nucleon energy spectra, equation of state, particle number fluctuations, and shear viscosity are calculated. The UrQMD results are compared with both, statistical mechanics and Chapman-Enskog kinetic theory, for a classical system of nucleons with hard-core repulsion.
[Submitted on 24 Oct 2017]
Minimization of the number of numerically calculated coefficients for new analytical forms as a product of exponential function r1 by the sum of the exponential terms Ai*exp(-ai*r2) have been done. The optimum is N=10. Calculations have been done for realistic phenomenological Reid93 potential. Spherical S0 and quadrupole S2 form factors is parameterized by the coefficients for deuteron wave function in coordinate representation. The result t20(p) in wide area of momentas for Reid93 potential agreed well with the literature results for other potential nucleon-nucleon models, and with experimental datas of world collaborations and reviews. The obtained results will allow studying the deuteron electromagnetic structure, its form-factors, differential cross section of double scattering in more detail in future, and also for calculations the theoretical values of spin observables in dp- scattering.
[Submitted on 23 Oct 2017] (cross-list from cond-mat.quant-gas)
Abhishek Mohapatra🇺🇸 · Eric Braaten🇺🇸
A general mechanism for the loss of conformal invariance is the merger and disappearance of an infrared fixed point and an ultraviolet fixed point of a renormalization group flow. We show explicitly how this mechanism works in the case of identical bosons at unitarity as the spatial dimension is varied. For between the critical dimensions and , there is loss of conformality as evidenced by the Efimov effect in the three-body sector. The beta function for an appropriate three-body coupling is a quadratic polynomial in that coupling. For and for , the beta function has two real roots that correspond to infrared and ultraviolet fixed points. As approaches from below and as approaches from above, the fixed points merge and disappear into the complex plane. For , the beta function has complex roots and the renormalization group flow for the three-body coupling is a limit cycle.
[Submitted on 24 Oct 2017] (cross-list from hep-th)
Yuya Tanizaki🇺🇸 · Tatsuhiro Misumi🇯🇵 · Norisuke Sakai🇯🇵
Anomaly matching constrains low-energy physics of strongly-coupled field theories, but it is not useful at finite temperature due to contamination from high-energy states. The known exception is an 't Hooft anomaly involving one-form symmetries as in pure Yang-Mills theory at . Recent development about large- volume independence, however, gives us a circumstantial evidence that 't Hooft anomalies can also remain under circle compactifications in some theories without one-form symmetries. We develop a systematic procedure for deriving an 't Hooft anomaly of the circle-compactified theory starting from the anomaly of the original uncompactified theory without one-form symmetries, where the twisted boundary condition for the compactified direction plays a pivotal role. As an application, we consider -twisted sigma model and massless -QCD, and compute their anomalies explicitly.
[Submitted on 24 Oct 2017] (cross-list from hep-ph)
Alejandro Ayala🇿🇦 · Saul Hernandez-Ortiz🇲🇽 · Luis A. Hernandez🇲🇽
We use the linear sigma model with quarks to study the QCD phase diagram from the point of view of chiral symmetry restoration. We compute the leading order effective potential for high and low temperatures and finite quark chemical potential, up to the contribution of the ring diagrams to account for the plasma screening effects. We fix the values of the model couplings using physical values for the input parameters such as the vacuum pion and sigma masses, the critical temperature at vanishing quark chemical potential and the conjectured end point value of the baryon chemical potential of the transition line at vanishing temperature. We also make the analysis for the same input parameters but with vanishing pion mass. We find that the critical end point (CEP) is located at low temperatures and high quark chemical potentials .
[Submitted on 24 Oct 2017] (cross-list from hep-lat)
Yi-Bo Yang🇺🇸 · Ying Chen🇨🇳 · Terrence Draper🇺🇸 · Jian Liang🇺🇸 · Keh-Fei Liu🇺🇸
We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of DWF configurations with three lattice spacings and volumes, and several pion masses including the physical pion mass. With 1-loop perturbative calculation and proper normalization of the glue operator, we find that the and quark masses contribute 9(2)\% to the proton mass. The quark energy and glue field energy contribute 31(5)\% and 37(5)\% respectively in the scheme at GeV. The trace anomaly gives the remaining 23(1)\% contribution. The and glue momentum fractions in the scheme are consistent with the global analysis at GeV.
[Submitted on 25 Oct 2017] (cross-list from hep-ph)
Gábor Bíró🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Tamás Sándor Biró🇭🇺 · Keming Shen🇨🇳
The latest, high-accuracy identified hadron spectra measurements in high-energy nuclear collisions led us to the investigation of the strongly interacting particles and collective effects in small systems. Since microscopical processes result in a statistical Tsallis-Pareto distribution, the fit parameters and are well suited for identifying system size scalings and initial conditions. Moreover, parameter values provide information on the deviation from the extensive, Boltzmann-Gibbs statistics in finite-volumes. We apply here the fit procedure developed in our earlier study for proton-proton collisions. The observed mass and energy trends in the hadron production are compared to RHIC dAu and LHC pPb data in different centrality/multiplicity classes. Here we present new results on mass hierarchy in pp and pA from light to heavy hadrons.
first authorsco-authorsvia INSPIRE