Properties of Infinite Nuclear Medium from QCD Sum Rules and the Neutron Star-Black Hole Mass Gap

A non-perturbative framework is provided to connect QCD with nuclear phenomenology in the intermediate and high density regime. Using QCD Sum Rules, in-medium scalar and vector self-energies of nucleons are calculated as functions of the density of an infinite nuclear medium. The self-energies are used in the relativistic mean field theory lagrangian of a high-density nuclear medium to find the binding energy of in-medium nucleons and the value of light quark condensate, $\langle \bar{q} q \rangle_{\rm{vac}} = -~(0.288 ~\rm{GeV})^3$, in the Borel-improved resummation scheme. The critical mass of an ideal neutron star is obtained by coupling a uniform saturation energy density of cold, dense nuclear matter to Einstein equation in hydrostatic equilibrium. Since it is less likely for a neutron star core to avoid deconfinement and enter the rigid vector repulsion phase where the speed of sound can smoothly approach from conformal to causal limit, a gap should exist in the stellar mass spectrum, $[3.48M_\odot, 5.47M_\odot]$, where it would be rare to find any isolated, cold, non-rotating neutron star or a black hole.Comment: 3 Figure

Scattering from finite-volume energies including higher partial waves and multiple decay channels

A new implementation of estimating the two-to-two $K$-matrix from finite-volume energies based on the Luescher formalism is described. The method includes higher partial waves and multiple decay channels, and the fitting procedure properly includes all covariances and statistical uncertainties. The method is also simpler than previously used procedures. Formulas and software for handling total spins up to $S=2$ and orbital angular momenta up to $L=6$ are presented.Comment: 8 pages. Presented at Lattice 2017, the 35th International Symposium on Lattice Field Theory, Granada, Spain, 18-24 June 201

Estimating the two-particle KK-matrix for multiple partial waves and decay channels from finite-volume energies

An implementation of estimating the two-to-two $K$-matrix from finite-volume energies based on the L\"uscher formalism and involving a Hermitian matrix known as the "box matrix" is described. The method includes higher partial waves and multiple decay channels. Two fitting procedures for estimating the $K$-matrix parameters, which properly incorporate all statistical covariances, are discussed. Formulas and software for handling total spins up to $S=2$ and orbital angular momenta up to $L=6$ are obtained for total momenta in several directions. First tests involving $\rho$-meson decay to two pions include the $L=3$ and $L=5$ partial waves, and the contributions from these higher waves are found to be negligible in the elastic energy range.Comment: 32 pages, 1 figur

Scattering from finite-volume energies including higher partial waves and multiple decay channels

A new implementation of estimating the two-to-two K-matrix from finitevolume energies based on the Luescher formalism is described. The method includes higher partial waves and multiple decay channels, and the fitting procedure properly includes all covariances and statistical uncertainties. The method is also simpler than previously used procedures. Formulas and software for handling total spins up to S = 2 and orbital angular momenta up to L = 6 are presented