Jul 26 – 30, 2021
US/Eastern timezone

Radius of convergence at finite chemical potential with rooted staggered fermions

Jul 27, 2021, 5:45 AM
15m
Oral presentation QCD at nonzero Temperature and Density QCD at nonzero Temperature and Density

Speaker

Sandor Katz (Eotvos University)

Description

In typical statistical mechanical systems the grand canonical partition function at finite volume is proportional to a polynomial of the fugacity $\exp(μ/T)$. The zero of this Lee-Yang polynomial closest to the origin determines the radius of convergence of the Taylor expansion of the pressure around $μ=0$. Rooted staggered fermions, with the usual definition of the rooted determinant, do not admit such a Lee-Yang polynomial. We show that the radius of convergence is then bounded by the spectral gap of the reduced matrix of the unrooted staggered operator. We suggest a new definition of the rooted staggered determinant at finite chemical potential that allows for a definition of a Lee-Yang polynomial. We perform a finite volume scaling study of the leading Lee-Yang zeros and estimate the radius of convergence extrapolated to infinite volume using stout improved staggered fermions on $N_t$=4 lattices. In the vicinity of the crossover temperature at zero chemical potential, the radius of convergence turns out to be at $μ_B/T$≈2 and roughly temperature independent.

Primary authors

Attila Pasztor (Eötvös University) Daniel Nogradi Kornél Kapás (Eötvös Loránd University, Budapest) Matteo Giordano (ELTE Eotvos Lorand University, Budapest) Sandor Katz (Eotvos University)

Presentation materials