arXiv subjects

Jacquelyn Noronha-Hostler

Publications and source records attributed to Jacquelyn Noronha-Hostler.

At least 37 records · Page 2Linked to original sources

arXiv2025

Shear viscosity from perturbative Quantum Chromodynamics to the hadron resonance gas at finite baryon, strangeness, and electric charge densities

Through model-to-data comparisons from heavy-ion collisions, it has been shown that the Quark Gluon Plasma has an extremely small shear viscosity at vanishing densities. At large baryon densities, significantly less is known about the nature of the shear viscosity from Quantum Chromodynamics (QCD). Within heavy-ion collisions, there are three conserved charges: baryon number (B), strangeness (S), and electric charge (Q). Here we calculate the shear viscosity in two limits using perturbative QCD and an excluded-volume hadron resonance gas at finite BSQ densities. We then develop a framework that interpolates between these two limits such that shear viscosity is possible to calculate across a wide range of finite BSQ densities. We find that the pQCD and hadron resonance gas calculations have different BSQ densities dependence such that a rather non-trivial shear viscosity appears at finite densities.

hep-ph↗

arXiv2025

Validity of a finite temperature expansion for dense nuclear matter

In this work we provide a new, well-controlled expansion of the equation of state of dense matter from zero to finite temperatures ($T$) while covering a wide range of charge fractions ($Y_Q$), from pure neutron to isospin symmetric nuclear matter. Our expansion can be used to describe neutron star mergers using the equation of state inferred from neutron star observations. We discuss how knowledge from low-energy nuclear experiments and heavy-ion collisions can be directly incorporated into the expansion. We also suggest new thermodynamic quantities of interest that can be calculated from theoretical models or directly inferred by experimental data that can be used to infer the finite temperature equation of state. With our new method, we can quantify the uncertainty in our finite $T$ and $Y_Q$ expansions without making assumptions about the underlying degrees of freedom. We can reproduce results from a microscopic equation of state up to $T=100$ MeV for baryon chemical potential $μ_B\gtrsim 1100$ MeV ($\sim1-2 \ n_{\rm sat}$) within $5\%$ error, with even better results for larger $μ_B$ and/or lower $T$. We investigate the sources of numerical and theoretical uncertainty and discuss future directions of study.

astro-ph.HE↗

arXiv2025

Initial-State Charge Density Predicts Final-State Net Charge Flow in Heavy-Ion Collisions

We propose a new class of charge-conjugation-odd flow observables and use them to investigate the dynamics of conserved currents in simulations of relativistic heavy-ion collisions. Inspired by the success of the initial energy and momentum distributions at predicting final-state anisotropic flow, we construct systematically-improvable initial-state estimators for final net-charge flow observables, which we validate with numerical simulations. This opens the possibility of a multitude of new charge-dependent probes of heavy-ion collisions of different systems and energies.

nucl-th↗

arXiv2025

Modern nuclear and astrophysical constraints of dense matter in a renormalized chiral approach

We explore the Quantum Chromodynamics (QCD) phase diagram's complexities, including quark deconfinement transitions, liquid-gas phase changes, and critical points, using the chiral mean-field (CMF) model that is able to capture all these features. We introduce a vector meson renormalization within the CMF framework, enabling precise adjustments of meson masses and coupling strengths related to vector meson interactions. Performing a new fit to the deconfinement potential, we are able to replicate recent lattice QCD results, low energy nuclear physics properties, neutron star observational data, and key phase diagram features as per modern constraints. This approach enhances our understanding of vector mesons' roles in mediating nuclear interactions and their impact on the equation of state, contributing to a more comprehensive understanding of the QCD phase diagram and its implications for nuclear and astrophysical phenomena.

nucl-th↗

arXiv2025

Anisotropic flow in fixed-target $^{208}$Pb+$^{20}$Ne collisions as a probe of quark-gluon plasma

The System for Measuring Overlap with Gas (SMOG2) at the LHCb detector enables the study of fixed-target ion-ion collisions at relativistic energies ($\sqrt{s_{\rm NN}}\sim100$ GeV in the centre-of-mass). With input from \textit{ab initio} calculations of the structure of $^{16}$O and $^{20}$Ne, we compute 3+1D hydrodynamic predictions for the anisotropic flow of Pb+Ne and Pb+O collisions, to be tested with upcoming LHCb data. This will allow the detailed study of quark-gluon plasma (QGP) formation as well as experimental tests of the predicted nuclear shapes. Elliptic flow ($v_2$) in Pb+Ne collisions is greatly enhanced compared to the Pb+O baseline due to the shape of $^{20}$Ne, which is deformed in a bowling-pin geometry. Owing to the large $^{208}$Pb radius, this effect is seen in a broad centrality range, a unique feature of this collision configuration. Larger elliptic flow further enhances the quadrangular flow ($v_4$) of Pb+Ne collisions via non-linear coupling, and impacts the sign of the kurtosis of the elliptic flow vector distribution ($c_2\{4\}$). Exploiting the shape of $^{20}$Ne proves thus an ideal method to investigate the formation of QGP in fixed-target experiments at LHCb, and demonstrates the power of SMOG2 as a tool to image nuclear ground states.

nucl-th↗

arXiv2025

Predictions for flow harmonic distributions and flow factorization ratios at RHIC

Data obtained at RHIC can be reproduced with relativistic viscous hydrodynamic simulations by adjusting the viscosity and initial conditions but it is difficult to disentangle these quantities. It is therefore important to find orthogonal observables to constrain the initial conditions separately from the viscosity. New observables have been measured at the LHC and shown to be sensitive to initial conditions and less to medium properties, specifically factorization breaking ratios appears to be promising. Here we consider two initial condition models, NeXus and TRENTO. While both models yield similar results for the scaled flow harmonic distributions both at the LHC and RHIC, they lead to quantitatively much more different patterns for the factorization breaking ratios at RHIC than at LHC, due to the shorter lifetime. Additionally, not only final state interactions but also initial free streaming matter in these ratio predictions and differences between these are enhanced at RHIC compared to LHC. Therefore experimental factorization breaking ratios at RHIC top energy (for transverse momentum) would be interesting to get.

nucl-th↗

arXiv2024

Jet cone radius dependence of $R_{AA}$ and $v_2$ at PbPb 5.02 TeV from JEWEL+$\rm T_RENTo$+v-USPhydro

We combine, for the first time, event-by-event $\rm T_RENTo$ initial conditions with the relativistic viscous hydrodynamic model v-USPhydro and the Monte Carlo event generator JEWEL to make predictions for the nuclear modification factor $R_{AA}$ and jet azimuthal anisotropies $v_n\left\{2\right\}$ in $\sqrt{s_{NN}}=5.02 \, \rm TeV$ PbPb collisions for multiple centralities and values of the jet cone radius $R$. The $R$-dependence of $R_{AA}$ and $v_2\left\{2\right\}$ strongly depends on the presence of recoiling scattering centers. We find a small jet $v_3\left\{2\right\}$ in mid-central collisions and consistent results in wide jet $p_T$ regions and centralities with ATLAS data.

nucl-th↗

arXiv2024

Imaging the initial condition of heavy-ion collisions and nuclear structure across the nuclide chart

High-energy nuclear collisions encompass three key stages: the structure of the colliding nuclei informed by low-energy nuclear physics, the initial condition (IC) leading to the formation of quark-gluon plasma (QGP), and the hydrodynamic expansion and hadronization of the QGP leading to final-state hadrons observed experimentally. Recent advances in experimental and theoretical methods have ushered in a precision era, enabling an increasingly accurate understanding of these stages. However, most approaches involve simultaneously determining both QGP properties and initial conditions from a single collision system, creating complexity due to the coupled contributions of various stages to the final-state observables. To avoid this, we propose leveraging known knowledge of low-energy nuclear structure and hydrodynamic observables to constrain the IC independently. By conducting comparative studies of collisions involving isobar-like nuclei - species with similar mass numbers but different structures - we disentangle the initial condition's impacts from the QGP properties. This approach not only refines our understanding of the IC but also turns high-energy experiments into a precision tool for imaging nuclear structures, offering insights that complement traditional low-energy approaches. Opportunities for carrying out such comparative experiments at the LHC and other facilities could significantly advance both high-energy and low-energy nuclear physics. Additionally, this approach has implications for the future EIC. While the possibilities are extensive, we focus on selected proposals that could benefit both the high-energy and low-energy nuclear physics communities. Originally prepared as input for the long-range plan of U.S. nuclear physics, this white paper reflects the status as of September 2022, with a brief update on developments since then.

nucl-ex↗

arXiv2024

RHIC $\sqrt{s_{NN}}=200$ GeV hadron yields and the isospin dependent equation of state

The statistical hadronization model has been successful in extracting information at chemical freeze-out in heavy-ion collisions. At RHIC, with a collision energy of $\sqrt{s_{NN}}=200$ GeV, many different ion species have been used for $A$+$A$ collisions. This allows for a scan across the charge fraction $Y_Q=Z/A$, where $Z$ is the proton number and $A$ is the baryon number. We first make predictions for $A$+$A$ collisions that do not yet have published experimental data on hadron yield ratios (O+O, Ru+Ru, Zr+Zr). We then use both the experimental and predicted yield ratios to perform thermal fits across $Y_Q$, enabling us to extract $s/n_B$ and other thermodynamic information at chemical freeze-out. Using the relation between $s/n_B$ and $Y_Q$, we can calculate a new constraint on the finite temperature equation of state at finite densities. We discuss implications of this constraint and propose future runs that can help connect to the equation of state relevant for neutron star mergers.

nucl-th↗

arXiv2024

Bayesian location of the QCD critical point from a holographic perspective

A fundamental question in QCD is the existence of a phase transition at large doping of quarks over antiquarks. We present the first prediction of a QCD critical point (CP) from a Bayesian analysis constrained by first principle results at zero doping. We employ the gauge/gravity duality to map QCD onto a theory of dual black holes. Predictions for the CP location in different realizations of the model overlap at one sigma. Even if many prior samples do not include a CP, one is found in nearly 100\% of posterior samples, indicating a strong preference for a CP.

nucl-th↗

arXiv2024

Unlocking "imprints" of conserved charges in the initial state of heavy-ion collisions

Hydrodynamic approaches to modeling relativistic high-energy heavy-ion collisions are based on the conservation of energy and momentum. However, the medium formed in these collisions also carries additional conserved quantities, including baryon number (B), strangeness (S), and electric charge (Q). In this Letter, we propose a new set of anisotropic flow observables designed to be exclusively sensitive to the effects of conserved BSQ charge fluctuations, providing insight into the initial state. Using the recently developed hydrodynamic framework \iccing{}+\ccake{}, we show that these new observables provide a measurable effect of initial BSQ charge fluctuations (ranging up to $\sim $10\%), which can be tested by experiments.

nucl-th↗

arXiv2024

State-of-the-art of Strangeness in Quark Matter Theory 2024

I discuss the theoretical developments in related to Strangeness in Quark Matter (SQM) leading up to the SQM2024 conference. These advances include mapping out the Quantum Chromodynamics phase diagram; puzzles that exist in hadron physics from light to heavy particles; and advanced in relativistic hydrodynamics with the inclusion of spin and magnetic fields.

nucl-th↗

arXiv2024

Structure in the speed of sound: from neutron stars to heavy-ion collisions

From the observation of both heavy neutron stars and light ones with small radii, one anticipates a steep rise in the speed of sound of nuclear matter as a function of baryon density up to values close to the causal limit. A question follows whether such behavior of the speed of sound in neutron-rich matter is compatible with the equation of state extracted from low-energy heavy-ion collisions. In this work, we consider a family of neutron star equations of state characterized by a steep rise in the speed of sound, and use the symmetry energy expansion to obtain equations of state applicable to the almost-symmetric nuclear matter created in heavy-ion collisions. We then compare collective flow data from low-energy heavy-ion experiments with results of simulations obtained using the hadronic transport code SMASH with the mean-field potential reproducing the density-dependence of the speed of sound. We show that equations of state featuring a peak in the speed of sound squared occurring at densities between 2-3 times the saturation density of normal nuclear matter, producing neutron stars of nearly M_max~2.5 M_Sun, are consistent with heavy-ion collision data.

nucl-th↗

arXiv2024

Theoretical and Experimental Constraints for the Equation of State of Dense and Hot Matter

This review aims at providing an extensive discussion of modern constraints relevant for dense and hot strongly interacting matter. It includes theoretical first-principle results from lattice and perturbative QCD, as well as chiral effective field theory results. From the experimental side, it includes heavy-ion collision and low-energy nuclear physics results, as well as observations from neutron stars and their mergers. The validity of different constraints, concerning specific conditions and ranges of applicability, is also provided.

nucl-th↗

arXiv2024

BSQ Conserved Charges in Relativistic Viscous Hydrodynamics solved with Smoothed Particle Hydrodynamics

Conservation laws play a crucial role in the modeling of heavy-ion collisions, including the those for charges such as baryon number (B), strangeness (S), and electric charge (Q). In this study, we present a new 2+1 relativistic viscous hydrodynamic code called CCAKE which uses the Smoothed Particle Hydrodynamics (SPH) formalism to locally conserve BSQ charges, together with an extended description of the multi-dimensional equation of state (EoS) obtained from lattice Quantum Chromodynamics. Initial conditions for CCAKE are supplied by the ICCING model, which samples gluon splittings into quark anti-quark pairs to generate the initial BSQ charge distributions. We study correlations between the BSQ charges and find that local BSQ fluctuations remain finite during the evolution, with corresponding chemical potentials of ($\sim100$--$200 \,\rm MeV$) at freeze-out. We find that our framework produces reasonable multiplicities of identified particles and that ICCING has no significant effect on the collective flow of all charged particles nor of identified particles when only one particle of interest is considered. However, we show specifically for Pb+Pb collisions at the LHC $\sqrt{s_{NN}}=5.02$ TeV that ICCING does have an effect on collective flow of identified particles if two particles of interest are considered.

nucl-th↗

arXiv2024

The unexpected uses of a bowling pin: exploiting $^{20}$Ne isotopes for precision characterizations of collectivity in small systems

Whether or not femto-scale droplets of quark-gluon plasma (QGP) are formed in so-called small systems at high-energy colliders is a pressing question in the phenomenology of the strong interaction. For proton-proton or proton-nucleus collisions the answer is inconclusive due to the large theoretical uncertainties plaguing the description of these processes. While upcoming data on collisions of $^{16}$O nuclei may mitigate these uncertainties in the near future, here we demonstrate the unique possibilities offered by complementing $^{16}$O$^{16}$O data with collisions of $^{20}$Ne ions. We couple both NLEFT and PGCM ab initio descriptions of the structure of $^{20}$Ne and $^{16}$O to hydrodynamic simulations of $^{16}$O$^{16}$O and $^{20}$Ne$^{20}$Ne collisions at high energy. We isolate the imprints of the bowling-pin shape of $^{20}$Ne on the collective flow of hadrons, which can be used to perform quantitative tests of the hydrodynamic QGP paradigm. In particular, we predict that the elliptic flow of $^{20}$Ne$^{20}$Ne collisions is enhanced by as much as 1.170(8)$_{\rm stat.}$(30)$_{\rm syst.}$ for NLEFT and 1.139(6)$_{\rm stat.}$(39)$_{\rm syst.}$ for PGCM relative to $^{16}$O$^{16}$O collisions for the 1% most central events. At the same time, theoretical uncertainties largely cancel when studying relative variations of observables between two systems. This demonstrates a method based on experiments with two light-ion species for precision characterizations of the collective dynamics and its emergence in a small system.

nucl-th↗

arXiv2024

Measuring jet energy loss fluctuations in the quark-gluon plasma via multiparticle correlations

The quark-gluon plasma (QGP) is a high temperature state of matter produced in the collisions of two nuclei at relativistic energies. The properties of this matter at short distance scales are probed using jets with high transverse momentum ($p_T$) resulting from quarks and gluons scattered with large momentum transfer in the earliest stages of the collisions. The Fourier harmonics for anisotropies in the high transverse momentum particle yield, $v_n(p_T)$, indicate the path length dependence of jet energy loss within the QGP. We present a framework to build off of measurements of jet energy loss using $v_n(p_T)$ by characterizing fluctuations in jet energy loss that are currently not constrained experimentally. In this paper, we utilize a set of multivariate moments and cumulants as new experimental observables to measure event-by-event fluctuations in the azimuthal anisotropies of rare probes, and compare them to the azimuthal anisotropies of soft particles. Ultimately, these fluctuations can be used to quantify the magnitude and fluctuations of event-by-event jet energy loss. We relate these quantities to existing multivariate cumulant observables, highlight their unique properties, and validate their sensitivities with a Monte Carlo simulation.

hep-ph↗

arXiv2024

Multi-particle correlations, cumulants, and moments sensitive to fluctuations in rare-probe azimuthal anisotropy in heavy ion collisions

Correlations of two or more particles have been an essential tool for understanding the hydrodynamic behavior of the quark-gluon plasma created in ultra-relativistic nuclear collisions. In this paper, we extend that framework to introduce a mathematical construction of multi-particle correlators that utilize correlations between arbitrary numbers of particles of interest (e.g. particles selected for their strangeness, heavy flavor, and conserved charges) and inclusive reference particles to estimate the azimuthal anisotropies of rare probes. To estimate the fluctuations and correlations in the azimuthal anisotropies of these particle of interest, we use these correlators in a system of cumulants, raw moments, and central moments. We finally introduce two classes of observables that can compare the fluctuations in the azimuthal anisotropies of particles of interest with reference particles at each order.

nucl-th↗