28 November 2022 to 2 December 2022
Europe/Zurich timezone

Towards locating the (real) critical end point

2 Dec 2022, 17:30
20m

Speaker

Friederike Ihssen (ITP Heidelberg)

Description

Lattice simulations and functional approaches established that QCD has no phase transition at small baryon chemical potential. However, second order phase transitions are expected at the conjectured critical endpoint at larger chemical potential and in the chiral limit at vanishing chemical potential.

These phase transitions leave an imprint as Lee-Yang edge singularities and can be found at high temperatures $T>T_c$ for complex magnetisation and complex chemical potential. For an increasing real part of the chemical potential, the edge singularity moves towards the real $\mu_B$-axis, potentially allowing for an extrapolation to the critical endpoint.

As a precursor for a quantitative study in QCD we discuss the impact of
fluctuations in a simple low energy effective theory, the non-linear
sigma model. We show that in this model the location of the phase
transition can accurately be determined by tracking the Lee-Yang
singularities in the complex plane. We close by discussing the
remaining task of extending this computation to full QCD.

Primary author

Friederike Ihssen (ITP Heidelberg)

Presentation materials