# QCD thermodynamics in the crossover/freeze-out region

We use results from a 6-th order Taylor expansion of the QCD equation of state to construct expansions for cumulants of conserved charge fluctuations and their correlations. We show that these cumulants strongly constrain the range of applicability of hadron resonance gas model calculations. We point out that the latter is inappropriate to describe equilibrium properties of QCD at zero and non-zero values of the baryon chemical potential already at T~155 MeV.

**Comments:**5 pages, 6 figures, contribution to the International Conference "Critical Point and Onset of Deconfinement 2016", Wroc{\l}aw, Poland, May 30th - June 4th, 2016

## Similar Publications

A symmetry-preserving treatment of a vector-vector contact interaction is used to study charmed heavy-light mesons. The contact interaction is a representation of nonperturbative kernels used in Dyson-Schwinger and Bethe-Salpeter equations of QCD. The Dyson-Schwinger equation is solved for the $u,\,d,\,s$ and $c$ quark propagators and the bound-state Bethe-Salpeter amplitudes respecting spacetime-translation invariance and the Ward-Green-Takahashi identities associated with global symmetries of QCD are obtained to calculate masses and electroweak decay constants of the pseudoscalar $\pi,\,K$, $D$ and $D_s$ and vector $\rho$, $K^*$, $D^*$, and $D^*_s$ mesons. Read More

**Authors:**C. Alexandrou

^{1}, M. Constantinou

^{2}, P. Dimopoulos

^{3}, R. Frezzotti

^{4}, K. Hadjiyiannakou

^{5}, K. Jansen

^{6}, C. Kallidonis

^{7}, B. Kostrzewa

^{8}, G. Koutsou

^{9}, M. Mangin-Brinet

^{10}, A. Vaquero Avilès-Casco

^{11}, U. Wenger

^{12}

**Affiliations:**

^{1}Univ. of Cyprus & The Cyprus Inst.,

^{2}Temple Univ.,

^{3}Centro Fermi & Rome Tor Vergata,

^{4}Rome Tor Vergata,

^{5}The Cyprus Inst.,

^{6}DESY-Zeuthen,

^{7}The Cyprus Inst.,

^{8}Bonn Univ.,

^{9}The Cyprus Inst.,

^{10}Grenoble,

^{11}Univ. of Utah,

^{12}Univ. of Bern

We present results on the light, strange and charm nucleon scalar and tensor charges from lattice QCD, using simulations with $N_f=2$ flavors of twisted mass Clover-improved fermions with a physical value of the pion mass. Both connected and disconnected contributions are included, enabling us to extract the isoscalar, strange and charm charges for the first time directly at the physical point. Furthermore, the renormalization is computed non-perturbatively for both isovector and isoscalar quantities. Read More

In recent years, the quasi parton distribution has been introduced for extracting the parton distribution functions from lattice QCD simulations. The quasi and standard distribution share the same perturbative collinear singularity and the renormalized quasi distribution can be factorized into the standard distribution with a perturbative matching factor. The quasi parton distribution is known to have power-law UV divergences, which do not exist in the standard distribution. Read More

We study a vectorial asymptotically free gauge theory, with gauge group $G$ and $N_f$ massless fermions in a representation $R$ of this group, that exhibits an infrared (IR) zero in its beta function, $\beta$, at the coupling $\alpha=\alpha_{IR}$ in the non-Abelian Coulomb phase. For general $G$ and $R$, we calculate the scheme-independent series expansions of (i) the anomalous dimension of the fermion bilinear, $\gamma_{\bar\psi\psi,IR}$, to $O(\Delta_f^4)$ and (ii) the derivative $\beta' = d\beta/d\alpha$, to $O(\Delta_f^5)$, both evaluated at $\alpha_{IR}$, where $\Delta_f$ is an $N_f$-dependent expansion variable. These are the highest orders to which these expansions have been calculated. Read More

The spin-independent and transversity generalised form factors (GFFs) of the $\phi$ meson are studied using lattice QCD calculations with light quark masses corresponding to a pion mass $m_\pi\sim450(5)$ MeV. One transversity and three spin-independent GFFs related to the lowest moments of leading-twist spin-independent and transversity gluon distributions are obtained at six non-zero values of the momentum transfer up to 1.2 GeV$^2$. Read More

We study the global symmetries of naive lattices Dirac operators in QCD-like theories in any dimension larger than two. In particular we investigate how the chosen number of lattice sites in each direction affects the global symmetries of the Dirac operator. These symmetries are important since they do not only determine the infra-red spectrum of the Dirac operator but also the symmetry breaking pattern and, thus, the lightest pseudo-scalar mesons. Read More

The topological charge density, topological susceptibility and its slope in momentum space $\chi^{\prime}(k^2)$ at momentum $k^{2}=0$ are determined by multi-probing approximation using overlap fermions in quenched SU(3) gauge theory. Then we investigate the topological structure of the quenched QCD vacuum, and compare it with result from the all-scale topological density, the results are consistent. Random permuted topological charge density is used to check whether these structures represent underlying ordered properties. Read More

We study decay properties of the $P$-wave charmed baryons using the method of light-cone QCD sum rules, including the $S$-wave decays of the flavor $\mathbf{\bar 3}_F$ $P$-wave charmed baryons into ground-state charmed baryons accompanied by a pseudoscalar meson ($\pi$ or $K$) or a vector meson ($\rho$ or $K^*$), and the $S$-wave decays of the flavor $\mathbf{6}_F$ $P$-wave charmed baryons into ground-state charmed baryons accompanied by a pseudoscalar meson ($\pi$ or $K$). We study both two-body and three-body decays which are kinematically allowed. We find two mixing solutions from internal $\rho$- and $\lambda$-mode excitations, which can well describe both masses and decay properties of the $\Lambda_c(2595)$, $\Lambda_c(2625)$, $\Xi_c(2790)$ and $\Xi_c(2815)$. Read More

A dual representation for non-Abelian lattice gauge theories where the new set of dynamical variables belong to the natural numbers $\mathbb{N}_{0}$ is discussed. After looking at the constraints on the dual variables due to gauge symmetry, the theory for the gauge group SU(2) is solved using Monte Carlo simulations based on Prokof'ev-Svistunov worm type of algorithms. The performance of the Monte Carlo is investigated for different types of updates. Read More

On the basis of the L\"uscher's finite volume formula, a simple test (sanity check) is introduced and applied to inspect the recent claims of the existence of the nucleon-nucleon ($NN$) bound state(s) for heavy quark masses in lattice QCD. We show that the consistency between the scattering phase shifts at $k^2 > 0$ and/or $k^2 < 0$ obtained from the lattice data and the behavior of phase shifts from the effective range expansion (ERE) around $k^2=0$ exposes the validity of the original lattice data, otherwise such information is hidden in the energy shift $\Delta E$ of the two nucleons on the lattice. We carry out this sanity check for all the lattice results in the literature claiming the existence of the $NN$ bound state(s) for heavy quark masses, and find that (i) some of the $NN$ data show clear inconsistency between the behavior of ERE at $k^2 > 0$ and that at $k^2 < 0$, (ii) some of the $NN$ data exhibit singular behavior of the low energy parameter (such as the divergent effective range) at $k^2<0$, (iii) some of the $NN$ data have the unphysical residue for the bound state pole in S-matrix, and (iv) the rest of the $NN$ data are inconsistent among themselves. Read More