Hadron resonance gas with repulsive interactions and fluctuations of conserved charges

Huovinen, Pasi; Petreczky, Péter

doi:10.1016/j.physletb.2017.12.001

Cited by 70 publications

(86 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2, agree very well with CEM-LQCD calculations, up to T ≃ 180 MeV, for all considered observables. Hence, the drastic temperature dependence of the baryon number fluctuations in this temperature range, as well as the particularly strong deviations from the ideal HRG baseline-the Skellam distribution-are convincingly interpreted in terms of repulsive baryonic interactions (see also [18,19,25]). …”

mentioning

confidence: 80%

See 1 more Smart Citation

Cluster expansion model for QCD baryon number fluctuations: No phase transition at μB/T<π

et al. 2018

View full text Add to dashboard Cite

A cluster expansion model (CEM), representing a relativistic extension of Mayer's cluster expansion, is constructed to study baryon number fluctuations in QCD. The temperature dependent first two coefficients, corresponding to the partial pressures in the baryon number B ¼ 1 and B ¼ 2 sectors, are the only model input, which we fix by recent lattice data at imaginary baryochemical potential. All other coefficients are constructed in terms of the first two and required to match the Stefan-Boltzmann limit of noninteracting quarks and gluons at T → ∞. The CEM allows calculations of the baryon number susceptibilities χ B k to arbitrary order. We obtain excellent agreement with all available lattice data for the baryon number fluctuation measures χ The grand canonical thermodynamic potential of QCD is an even function of the real baryon chemical potential μ B because of the CP-symmetry. Taking the quantization of the baryon charge into account, the QCD pressure has a fugacity expansionThis relation can formally be viewed as a relativistic extension of Mayer's cluster expansion in fugacities [1]. A similar formalism is also employed in the canonical approach [2][3][4][5], where the fugacity expansion is applied to the partition function Z itself (see Refs. [6,7] for recent developments).The net baryon density readswhere b k ðTÞ ≡ kp k ðTÞ. Analytic continuation to an imaginary chemical potential yields a purely imaginary ρ B =T 3 , with b k ðTÞ becoming its Fourier expansion coefficients. The analytic continuation to/from imaginary μ is one of the methods used to study QCD at finite net baryon density [8][9][10][11][12][13][14][15][16]. The leading four Fourier coefficients b k were studied in Refs. [17,18] using lattice simulations with physical quark masses at imaginary μ B , as well as phenomenological models.At low temperatures, below the crossover transition, a behavior similar to an uncorrelated gas of hadrons, i.e., jb k ðTÞ=b 1 ðTÞj ≪ 1 for k ≥ 2, is seen in lattice QCD (LQCD) [17,18]. Lattice simulations at T > 135 MeV yield negative b 2 ðTÞ values, which could be interpreted in terms of repulsive baryonic interactions. The first four LQCD Fourier coefficients, up to T ≃ 185 MeV, can indeed be described rather well by a hadron resonance gas (HRG) model with excluded-volume (EV) interactions between the (anti)

show abstract

mentioning

confidence: 80%

“…In an alternative CEM-HRG, b 1 ðTÞ and b 2 ðTÞ are taken from the HRG-EV model with a constant bðTÞ ¼ 1 fm 3 value [18][19][20]. Note that, for a calculation of the pressure using the CEM, also the partial pressure p 0 ðTÞ in the jBj ¼ 0 sector is required as input.…”

mentioning

confidence: 99%

Cluster expansion model for QCD baryon number fluctuations: No phase transition at μB/T<π

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In previous studies [11,23,[53][54][55] it was customary to compare the ratio estimators for the Taylor expansion in the baryon number chemical potential to the hadron resonance gas [56,57]. As there is no finite µ transition in this model, when such a comparison yields results consistent with the HRG one concludes that there are no signs of criticality in the fluctuations under scrutiny.…”

Section: Numerical Results For the Convergence Radius Estimatorsmentioning

confidence: 99%

Reliable estimation of the radius of convergence in finite density QCD

Giordano

Pásztor

2019

Phys. Rev. D

View full text Add to dashboard Cite

We study different estimators of the radius of convergence of the Taylor series of the pressure in finite density QCD. We adopt the approach in which the radius of convergence is estimated first in a finite volume, and the infinite-volume limit is taken later. This requires an estimator for the radius of convergence that is reliable in a finite volume. Based on general arguments about the analytic structure of the partition function in a finite volume, we demonstrate that the ratio estimator cannot work in this approach, and propose three new estimators, capable of extracting reliably the radius of convergence, which coincides with the distance from the origin of the closest Lee-Yang zero. We also provide an estimator for the phase of the closest Lee-Yang zero, necessary to assess whether the leading singularity is a true critical point. We demonstrate the usage of these estimators on a toy model, namely 4 flavors of unimproved staggered fermions on a small 6 3 × 4 lattice, where both the radius of convergence and the Taylor coefficients to any order can be obtained by a direct determination of the Lee-Yang zeros. Interestingly, while the relative statistical error of the Taylor expansion coefficients steadily grows with order, that of our estimators stabilizes, allowing for an accurate estimate of the radius of convergence. In particular, we show that despite the more than 100% error bars on high-order Taylor coefficients, the given ensemble contains enough information about the radius of convergence.

show abstract

“…Furthermore, M is the nucleon mass and K 2 (x) is the Bessel function of second kind. The virial coefficient b 2 (T ) can be evaluated using the experimentally measured phase shifts to parametrise the S-matrix, and it turns out that b 2 (T ) is negative [15], see Fig. 1.…”

Section: Nucleon Gas With Repulsive Mean Field and Virial Expansionmentioning

confidence: 99%

“…The largest value allowed for K by the virial expansion is around K = 450 MeV/fm 3 . It is straightforward to generalise the mean-field approach to a multicomponent system if one assumes that the repulsive mean-field is the same for all ground state baryons [15], and the baryon resonances are not affected by the mean field. Within this approach we calculated baryon number fluctuations defined as derivatives of the pressure with respect to baryon chemical potential [15]…”

Section: Nucleon Gas With Repulsive Mean Field and Virial Expansionmentioning

confidence: 99%

Hadron gas with repulsive mean field

Huovinen¹,

Petreczky²

2019

Proceedings of XIII Quark Confinement and the Hadron Spectrum — PoS(Confinement2018)

Self Cite

View full text Add to dashboard Cite

We study the QCD equation of state, and fluctuations of baryon number and strangeness using the hadron resonance gas model with repulsive mean field. We find that including both the predicted but not observed resonances, a.k.a. missing states, and the repulsive mean field into the resonance gas model leads to better description of the lattice results. The repulsive mean field is particularly important for the higher order baryon number fluctuations.

show abstract

Hadron resonance gas with repulsive interactions and fluctuations of conserved charges

Cited by 70 publications

References 45 publications

Cluster expansion model for QCD baryon number fluctuations: No phase transition at μB/T<π

Cluster expansion model for QCD baryon number fluctuations: No phase transition at μB/T<π

Reliable estimation of the radius of convergence in finite density QCD

Hadron gas with repulsive mean field

Contact Info

Product

Resources

About