[RBRC seminar] A New Way to Resum the Finite-Density Lattice QCD Taylor Series
by
Prasad Hegde
( Indian Institute of Science, Bangalore, India)
→
US/Eastern
Description
Lattice QCD at finite chemical potential $\mu_B$ is an unsolved problem due to the Sign Problem. Of the various partial solutions that have been proposed, the method of Taylor expansion has been shown to yield reliable estimates for observables such as the QCD equation of state. However, the convergence of the Taylor series is slow and the calculation of the higher-order Taylor coefficients is extremely challenging. Hence, it is necessary to resum the Taylor series. A common method of resummation is the method of Pade approximants. In this talk, I will describe another way to resum the Taylor series. The method resums the contribution of the lower-order derivatives of the fermion matrix to all orders in $\mu_B$. Thus it provides an improved estimate of the QCD equation of state. It also allows us to investigate the analytic structure of the QCD partition function in the complex-$\mu_B$ plane. Lastly, it can also be connected to other approaches to finite-density QCD such as reweighting. In this talk, I will describe the method and our results and the possible implications for the QCD phase diagram.
