Tue·Sep 18, 2007Tuesday·September 18, 2007

1. 01*

   Phase Quenched Lattice QCD at Finite Density and Temperature

   D. K. Sinclair🇺🇸 · J. B. Kogut🇺🇸

   We simulate 3-flavour lattice QCD at finite quark-number chemical potential mu in the phase-quenched approximation, close to the finite temperature transition. Working close to the critical quark mass, we find no evidence for the expected critical endpoint at small mu. We are performing further simulations aimed at calculating the equation-of-state of this theory outside of the superfluid domain, where its phase structure is expected to mimic the full theory.

   hep-latPoS(2007)·7 citations
2. 02*

   Yang-Mills Ground State in 2+1 Dimensions and Temporal Gauge

   J. Greensite🇺🇸 · S. Olejnik🇸🇰

   A gauge-invariant wavefunctional is proposed as an approximation to the ground state of Yang-Mills theory in 2+1 dimensions, quantized in temporal gauge. The proposed vacuum state is the true ground state of the appropriate Hamiltonian in both the free-field limit, and in a zero mode strong-field limit. Confinement, in this approach, arises via dimensional reduction, and we present numerical results for the mass gap. The issue of color screening is briefly discussed.

   hep-latPoS(2007)·2 citations
3. 03*

   Three-boson problem at low energy and Implications for dilute Bose-Einstein condensates

   Shina Tan🇺🇸

   It is shown that the effective interaction strength of three bosons at small collision energies can be extracted from their wave function at zero energy. An asymptotic expansion of this wave function at large interparticle distances is derived, from which is defined a quantity $D$ named three-body scattering hypervolume, which is an analog of the two-body scattering length. Given any finite-range interaction potentials, one can thus predict the effective three-body force from a numerical solution of the Schrödinger equation. In this way the constant $D$ for hard-sphere bosons is computed, leading to the complete result for the ground state energy per particle of a dilute Bose-Einstein condensate (BEC) of hard spheres to order ${\rho }^2$, where $\rho$ is the number density. Effects of $D$ are also demonstrated in the three-body energy in a finite box of size $L$, which is expanded to the order $L^{-7}$, and in the three-body scattering amplitude in vacuum. Another key prediction is that there is a violation of the effective field theory (EFT) in the condensate fraction in dilute BECs, caused by short-range physics. EFT predictions for the ground state energy and few-body scattering amplitudes, however, are corroborated.

   ↳ cond-mat.stat-mechhep-latnucl-thPRA(2008)·80 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.