151 research outputs found
Effect of the QCD equation of state and strange hadronic resonances on multiparticle correlations in heavy ion collisions
Mapping out the thermodynamic stability of a QCD equation of state with a critical point using active learning
The Beam Energy Scan Theory (BEST) collaboration's equation of state (EoS)
incorporates a 3D Ising model critical point into the Quantum Chromodynamics
(QCD) equation of state from lattice simulations. However, it contains 4 free
parameters related to the size and location of the critical region in the QCD
phase diagram. Certain combinations of the free parameters lead to acausal or
unstable realizations of the EoS that should not be considered. In this work,
we use an active learning framework to rule out pathological EoS efficiently.
We find that checking stability and causality for a small portion of the
parameters' range is sufficient to construct algorithms that perform with
96% accuracy across the entire parameter space. Though in this work we focus
on a specific case, our approach can be generalized to any EoS containing a
parameter space-class correspondence.Comment: 14 pages, 9 figure
Topological features of the deconfinement transition
The first order transition between the confining and the center symmetry
breaking phases of the SU(3) Yang-Mills theory is marked by discontinuities in
various thermodynamics functions, such as the energy density or the value of
the Polyakov loop. We investigate the non-analytical behaviour of the
topological susceptibility and its higher cumulant around the transition
temperature and make the connection to the curvature of the phase diagram in
the plane and to the latent heat.Comment: 13 pages, 10 figure
Lattice-QCD-based equations of state at finite temperature and density
The equation of state (EoS) of QCD is a crucial input for the modeling of
heavy-ion-collision (HIC) and neutron-star-merger systems. Calculations of the
fundamental theory of QCD, which could yield the true EoS, are hindered by the
infamous Fermi sign problem which only allows direct simulations at zero or
imaginary baryonic chemical potential. As a direct consequence, the current
coverage of the QCD phase diagram by lattice simulations is limited. In these
proceedings, two different equations of state based on first-principle lattice
QCD (LQCD) calculations are discussed. The first is solely informed by the
fundamental theory by utilizing all available diagonal and non-diagonal
susceptibilities up to in order to reconstruct a full
EoS at finite baryon number, electric charge and strangeness chemical
potentials. For the second, we go beyond information from the lattice in order
to explore the conjectured phase structure, not yet determined by LQCD methods,
to assist the experimental HIC community in their search for the critical
point. We incorporate critical behavior into this EoS by relying on the
principle of universality classes, of which QCD belongs to the 3D Ising Model.
This allows one to study the effects of a singularity on the thermodynamical
quantities that make up the equation of state used for hydrodynamical
simulations of HICs. Additionally, we ensure that these EoSs are valid for
applications to HICs by enforcing conditions of strangeness neutrality and
fixed charge-to-baryon-number ratio.Comment: Contribution to the 37th Winter Workshop on Nuclear Dynamics. arXiv
admin note: text overlap with arXiv:2103.0814
First results from CROP-11 deep seismic profile, central Apennines, Italy:evidence of mid-crustal folding.
Geophysical and geological data used to reconstruct the deep structures of central Ital
First results from the CROP-11 deep seismic profile, central Apennines, Italy: evidence of mid-crustal folding
The CROP-11 deep seismic profile across the central Apennines, Italy, reveals a previously unknown, mid-crustal antiform here interpreted as a fault-bend fold-like structure. The seismic facies and gravity signature suggest that this structure consists of low-grade metamorphic rocks. Geomorphological, stratigraphic and tectonic evidence in the overlying shallow thrusts suggests that this structure developed in early to mid-Messinian time and grew out of sequence in late Messinian–
Pliocene time. The out-of-sequence growth may reflect a taper subcriticality stage of the Apenninic thrust wedge, which
induced renewed contraction in the rear.Published583–586ope
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