QCD at nonzero chemical potential: Recent progress on the lattice

  title={QCD at nonzero chemical potential: Recent progress on the lattice},
  author={Gert Aarts and Felipe Attanasio and Benjamin Jager and Erhard Seiler and D{\'e}nes Sexty and Ion-Olimpiu Stamatescu},
We summarise recent progress in simulating QCD at nonzero baryon density using complex Langevin dynamics. After a brief outline of the main idea, we discuss gauge cooling as a means to control the evolution. Subsequently we present a status report for heavy dense QCD and its phase structure, full QCD with staggered quarks, and full QCD with Wilson quarks, both directly and using the hopping parameter expansion to all orders. 

Figures from this paper

Current status of dynamical modeling of fluctuations at the QCD phase transition in heavy-ion collisions

For a complete understanding of the QCD phase diagram it is important to connect first-principle thermodynamic calculations to experimental data from the RHIC Beam Energy Scan and the future

Complex Langevin in Lattice QCD: dynamic stabilisation and the phase diagram

Complex Langevin simulations provide an alternative to sample path integrals with complex weights and therefore are suited to determine the phase diagram of QCD from first principles. We use our

Towards a theoretical description of dense QCD

The properties of matter at finite baryon densities play an important role for the astrophysics of compact stars as well as for heavy ion collisions or the description of nuclear matter. Because of

Improved convergence of Complex Langevin simulations

The sign problem appears in lattice QCD as soon as a non-zero chemical potential is introduced. This prevents direct simulations to determine the phase structure of the strongly interacting matter.

Heavy dense QCD from a 3d effective lattice theory

The cold and dense regime of the QCD phase diagram is to this day inaccessible to first principle lattice calculations owing to the sign problem. Here we present progress of an ongoing effort to

The QCD phase diagram in the limit of heavy quarks using complex Langevin dynamics

A bstractComplex Langevin simulations allow numerical studies of theories that exhibit a sign problem, such as QCD, and are thereby potentially suitable to determine the QCD phase diagram from first

Hopping parameter expansion to all orders using the complex Langevin equation

We propose two novel formulations of the hopping parameter expansion for finite density QCD using Wilson fermions, while keeping the gauge action intact. We use the complex Langevin equation to

Interplay of Mesonic and Baryonic Degrees of Freedom in Quark Matter

In this work we study the influence of mesonic and baryonic fluctuations on the phase dia- gram of quark matter with two flavors. By examining the hadronization process and related techniques, we

Effective Field Theory for Baryon Masses

Mass is one of the most fundamental properties of matter. Understanding its origin has long been a central topic in physics. According to modern particle and nuclear physics, the key to this issue is

Cooling Stochastic Quantization with colored noise

Smoothing of field configurations is highly important for precision calculations of physical quantities on the lattice. We present a cooling method based on Stochastic Quantization with a built-in UV



High density QCD with static quarks.

In this approximation, the deconfinement transition seen at zero density becomes a smooth crossover at very small density (possibly for any nonzero density), and that at low enough temperature chiral symmetry remains broken at all densities.

Developments in lattice QCD for matter at high temperature and density

A brief overview of the QCD phase diagram at nonzero temperature and density is provided. It is explained why standard lattice QCD techniques are not immediately applicable for its determination, due

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

We present results of our ongoing studies of an effective three-dimensional theory of thermal lattice QCD with heavy Wilson quarks. This is done by combined strong coupling and hopping parameter

Simulating QCD at nonzero baryon density to all orders in the hopping parameter expansion

Progress in simulating QCD at nonzero baryon density requires, amongst others, substantial numerical effort. Here we propose two different expansions to all orders in the hopping parameter,

Onset transition to cold nuclear matter from lattice QCD with heavy quarks.

This work studies the onset of nuclear matter employing a three-dimensional effective theory derived by combined strong coupling and hopping expansions, which is valid for heavy but dynamical quarks and has a mild sign problem only.

The QCD deconfinement transition for heavy quarks and all baryon chemical potentials

A bstractUsing combined strong coupling and hopping parameter expansions, we derive an effective three-dimensional theory from thermal lattice QCD with heavy Wilson quarks. The theory depends on

Simulating QCD at finite density

In this review, I recall the nature and the inevitability of t he “sign problem” which plagues attempts to simulate lattice QCD at finite baryon density. I pre sent the main approaches used to

Complex Langevin dynamics and other approaches at finite chemical potential

I review the presence of the sign problem in lattice QCD at nonzero baryon density and its relation with the overlap and Silver Blaze problems. I then discuss progress in some cases where the sign