Onset Transition to Cold Nuclear Matter from Lattice QCD with Heavy Quarks

140

A three-dimensional effective lattice theory of Polyakov loops is derived from QCD by expansions in the fundamental character of the gauge action, u, and the hopping parameter, κ, whose action is correct to κ n u m with n + m = 4. At finite baryon density, the effective theory has a sign problem which meets all criteria to be simulated by complex Langevin as well as by Monte Carlo on small volumes. The theory is valid for the thermodynamics of heavy quarks, where its predictions agree with simulations of full QCD at zero and imaginary chemical potential. In its region of convergence, it is moreover amenable to perturbative calculations in the small effective couplings. In this work we study the challenging cold and dense regime. We find unambiguous evidence for the nuclear liquid gas transition once the baryon chemical potential approaches the baryon mass, and calculate the nuclear equation of state in the limit of heavy baryons. In particular, we find a negative binding energy per nucleon causing the condensation, whose absolute value decreases exponentially as mesons get heavier. For decreasing meson mass, we observe a first order liquid gas transition with an endpoint at some finite temperature, as well as a gap between the onset of isospin and baryon condensation.

Section: Comparison With Monte Carlomentioning

confidence: 74%

“…For the case of N f = 1 we previously observed the onset transition as a step function from zero density to lattice saturation [10].…”

Section: Jhep09(2014)131mentioning

confidence: 78%

Section: Jhep09(2014)131mentioning

confidence: 94%

Section: Simulation Of the Effective Theory By Complex Langevinmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Heavy dense QCD and nuclear matter from an effective lattice theory

Langelage

Neuman

Philipsen

2014

140

Large N lattice QCD and its extended strong-weak connection to the hypersphere

Christensen¹,

Myers²,

Pedersen³

2014

We calculate an effective Polyakov line action of QCD at large N c and large N f from a combined lattice strong coupling and hopping expansion working to second order in both, where the order is defined by the number of windings in the Polyakov line. We compare with the action, truncated at the same order, of continuum QCD on S 1 × S d at weak coupling from one loop perturbation theory, and find that a large N c correspondence of equations of motion found in [1] at leading order, can be extended to the next order. Throughout the paper, we review the background necessary for computing higher order corrections to the lattice effective action, in order to make higher order comparisons more straightforward.

Two-flavor lattice QCD with a finite density of heavy quarks: heavy-dense limit and “particle-hole” symmetry

Rindlisbacher

Forcrand

2016

Abstract:We investigate the properties of the half-filling point in lattice QCD (LQCD), in particular the disappearance of the sign problem and the emergence of an apparent particle-hole symmetry, and try to understand where these properties come from by studying the heavy-dense fermion determinant and the corresponding strong-coupling partition function (which can be integrated analytically). We then add in a first step an effective Polyakov loop gauge action (which reproduces the leading terms in the character expansion of the Wilson gauge action) to the heavy-dense partition function and try to analyze how some of the properties of the half-filling point change when leaving the strong coupling limit. In a second step, we take also the leading nearest-neighbor fermion hopping terms into account (including gauge interactions in the fundamental representation) and mention how the method could be improved further to incorporate the full set of nearest-neighbor fermion hoppings. Using our mean-field method, we also obtain an approximate (µ, T ) phase diagram for heavy-dense LQCD at finite inverse gauge coupling β. Finally, we propose a simple criterion to identify the chemical potential beyond which lattice artifacts become dominant.