Abstract
We investigate the order of the finite temperature chiral symmetry restoration transition for QCD with two massless fermions, by using a novel method, based on simulating imaginary values of the quark chemical potential $\mu=i\mu_i,\mu_i\in\mathbb{R}$. Our method exploits the fact that, for low enough quark mass $m$ and large enough chemical potential $\mu_i$, the chiral transition is decidedly first order, then turning into crossover at a critical mass $m_c(\mu)$. It is thus possible to determine the critical line in the $m - \mu^2$ plane, which can be safely extrapolated to the chiral limit by taking advantage of the known tricritical indices governing its shape. We test this method with standard staggered fermions and the result of our simulations is that $m_c(\mu=0)$ is positive, so that the phase transition at zero density is definitely first order in the chiral limit, on our coarse $N_t=4$ lattices with $a\simeq 0.3\,\mathrm{fm}$.
Highlights
Claudio Bonati*Dipartimento di Fisica dell’Università di Pisa and INFN - Sezione di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
Quantum chromodynamics is known to undergo a finite temperature “transition” at which both partial deconfinement and partial chiral symmetry restoration take place
This is consistent with the fact that the global symmetries of QCD associated with the transition are only exact in the limits of infinite quark masses or of massless quarks: only in
Summary
Dipartimento di Fisica dell’Università di Pisa and INFN - Sezione di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy. It is possible to determine the critical line in the m − μ2 plane, which can be safely extrapolated to the chiral limit by taking advantage of the known tricritical indices governing its shape. We test this method with standard staggered fermions and the result of our simulations is that mcðμ 1⁄4 0Þ is positive, so that the phase transition at zero density is definitely first order in the chiral limit, on our coarse Nt 1⁄4 4 lattices with a ≃ 0.3 fm
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.