Nuclear Theory·nucl-th

Friday·June 16, 2023

23 papers—11 primary·12 cross-listed

01
Neutron star matter based on a parity doublet model including the $a_{0} (980)$ meson
Yuk Kei Kong🇯🇵 · Takuya Minamikawa🇯🇵 · Masayasu Harada🇯🇵
We study the effect of the isovector-scalar meson $a_{0}$ (980) on the properties of nuclear matter and the neutron star (NS) matter by constructing a parity doublet model with including the $a_{0}$ meson based on the chiral SU(2) $_{L} \times$ SU(2) $_{R}$ symmetry. We also include the $ω$ - $ρ$ mixing contribution to adjust the slope parameter at the saturation. We find that, when the chiral invariant mass of nucleon $m_{0}$ is smaller than about 800 MeV, the existence of $a_{0}$ (980) enlarges the symmetry energy by strengthening the repulsive $ρ$ meson coupling. On the other hand, for large $m_{0}$ where the Yukawa coupling of $a_{0}$ (980) to nucleon is small, the symmetry energy is reduced by the effect of $ω$ - $ρ$ mixing. We then construct the equation of state (EoS) of a neutron star matter to obtain the mass-radius relation of NS. We find that, in most choices of $m_{0}$ , the existence of $a_{0}$ (980) stiffens the EoS and makes the radius of NS larger. We then constrain the chiral invariant mass of nucleon from the observational data of NS, and find that $580 MeV ≲ m_{0} ≲ 860 MeV$ for $L_{0} = 57.7$ MeV.
nucl-thastro-ph.HEhep-phPRC(2023)·24 citations
02
Classical and Bayesian error analysis of the relativistic mean-field model for doubly magic nuclei
M. Imbrišak · K. Nomura
The information-geometric statistical analysis on the stability of model reductions, reported previously [Imbrišak and Nomura, Phys. Rev. C 107, 034304 (2023)] with a focus on the manifold boundary approximation method in the application to the nuclear density-dependent point-coupling model of infinite nuclear matter, is extended to the numerically more challenging case of finite nuclei. A simple procedure is presented for determining the binding energies of doubly magic nuclei within the relativistic mean-field framework using the Woods-Saxon potential. The proposed procedure, employing the Fisher information matrix combined with algorithmic differentiation, is shown to provide reliable estimates of parameter uncertainties of the nuclear energy density functional for finite nuclei, while reducing the time-consuming sampling of the parameter space, which would be required in the numerically more involved Bayesian statistical techniques.
nucl-thPRC(2023)·2 citations
03
Core States of Neutron Stars from Anatomizing their Scaled Structure Equations
Bao-Jun Cai🇨🇳 · Bao-An Li🇺🇸 · Zhen Zhang🇨🇳
Given an Equation of State (EOS) for neutron star (NS) matter, there is a unique mass-radius sequence characterized by a maximum mass $M_{NS}^{m a x}$ at radius $R_{m a x}$ . We first show analytically that the $M_{NS}^{m a x}$ and $R_{m a x}$ scale linearly with two different combinations of NS central pressure $P_{c}$ and energy density $ε_{c}$ by dissecting perturbatively the dimensionless Tolman-Oppenheimer-Volkoff (TOV) equations governing NS internal variables. The scaling relations are then verified via 87 widely used and rather diverse phenomenological as well as 17 microscopic NS EOSs with/without considering hadron-quark phase transitions and hyperons by solving numerically the original TOV equations. The EOS of densest NS matter allowed before it collapses into a black hole (BH) is then obtained. Using the universal $M_{NS}^{m a x}$ and $R_{m a x}$ scalings and NICER (Neutron Star Interior Composition Explorer) and XMM-Newton mass-radius observational data for PSR J0740+6620, a very narrow constraining band on the NS central EOS is extracted directly from the data for the first time without using any specific input EOS model.
nucl-thastro-ph.HEnucl-exApJ(2023)·24 citations
04
Generative deep-learning reveals collective variables of Fermionic systems
Raphaël-David Lasseri · David Regnier · Mikaël Frosini · Marc Verriere · Nicolas Schunck
Complex processes ranging from protein folding to nuclear fission often follow a low-dimension reaction path parameterized in terms of a few collective variables. In nuclear theory, variables related to the shape of the nuclear density in a mean-field picture are key to describing the large amplitude collective motion of the neutrons and protons. Exploring the adiabatic energy landscape spanned by these degrees of freedom reveals the possible reaction channels while simulating the dynamics in this reduced space yields their respective probabilities. Unfortunately, this theoretical framework breaks down whenever the systems encounters a quantum phase transition with respect to the collective variables. Here we propose a generative-deep-learning algorithm capable of building new collective variables highly representative of a nuclear process while ensuring a differentiable mapping to its Fermionic wave function. Within this collective space, the nucleus can evolve continuously from one of its adiabatic quantum phase to the other at the price of crossing a potential energy barrier. This approach applies to any Fermionic system described by a single Slater determinant, which encompasses electronic systems described within the density functional theory.
nucl-thquant-phPRC(2024)·5 citations
05
Manipulation of Giant Multipole Resonances via Vortex $γ$ Photons
Zhi-Wei Lu · Liang Guo · Zheng-Zheng Li · Mamutjan Ababekri · Fang-Qi Chen · Changbo Fu · Chong Lv · Ruirui Xu · Xiangjin Kong · Yi-Fei Niu · Jian-Xing Li
Traditional photonuclear reactions primarily excite giant dipole resonances, making the measurement of isovector giant resonances with higher multipolarties a great challenge. In this work, the manipulation of collective excitations of different multipole transitions in nuclei via vortex $γ$ photons has been investigated. We develop the calculation method for photonuclear cross sections induced by the vortex $γ$ photon beam using the fully self-consistent random-phase approximation plus particle-vibration coupling (RPA+PVC) model based on Skyrme density functional. We find that the electromagnetic transitions with multipolarity $J < m_{γ}$ are forbidden for vortex $γ$ photons due to the angular momentum conservation, with $m_{γ}$ being the projection of total angular momentum of $γ$ photon on its propagation direction. For instance, this allows for probing the isovector giant quadrupole resonance without interference from dipole transitions using vortex $γ$ photons with $m_{γ} = 2$ . The electromagnetic transitions with $J > m_{γ}$ are strongly suppressed compared with the plane-wave- $γ$ -photon case, and even vanish at specific polar angles. Therefore, the giant resonances with specific multipolarity can be extracted via vortex $γ$ photons. Moreover, the vortex properties of $γ$ photons can be meticulously diagnosed by measuring the nuclear photon-absorption cross section. Our method opens new avenues for photonuclear excitations, generation of coherent $γ$ photon laser and precise detection of vortex particles, and consequently, has significant impact on nuclear physics, nuclear astrophysics and strong laser physics.
nucl-thPRL(2023)·50 citations
06
Stochastic fluctuations in relativistic fluids: causality, stability, and the information current
Nicki Mullins (Illinois U., Urbana)🇺🇸 · Mauricio Hippert (Illinois U., Urbana)🇺🇸 · Jorge Noronha (Illinois U., Urbana)🇺🇸
We develop a general formalism for introducing stochastic fluctuations around thermodynamic equilibrium which takes into account, for the first time, recent developments on the causality and stability properties of relativistic hydrodynamic theories. The method is valid for any covariantly stable theory of relativistic viscous fluid dynamics derived from a covariant maximum entropy principle. We illustrate the formalism with some applications, showing how it could be used to consistently introduce fluctuations in a model of relativistic heat diffusion, and in conformally invariant Israel-Stewart theory in a general hydrodynamic frame. The latter example is used to study the hydrodynamic frame dependence of the symmetric two-point function of fluctuations of the energy-momentum tensor.
nucl-thhep-phhep-thPRD(2023)·25 citations
07
Bayesian parameter estimation with a new three-dimensional initial-conditions model for ultrarelativistic heavy-ion collisions
Derek Soeder🇺🇸 · Weiyao Ke🇺🇸 · J.-F. Paquet🇺🇸 · Steffen A. Bass🇺🇸
We extend the well-studied midrapidity TRENTo initial-conditions model to three dimensions, thus facilitating (3+1)D modeling and analysis of ultrarelativistic heavy-ion collisions at RHIC and LHC energies. TRENTo-3D is a fast, parametric model of the 3D initial-state geometry, capable of providing initial conditions for (3+1)D models of quark--gluon plasma formation and evolution. It builds on TRENTo's success at modeling the initial nuclear participant thicknesses, longitudinally extending the initial deposition to form a central fireball near midrapidity and two fragmentation regions at forward and backward rapidities. We validate the new model through a large-scale Bayesian calibration, utilizing as observables the rapidity distributions of charged hadrons. For computational efficiency the present effort employs a (1+1)D linearized approximation of ideal hydrodynamics as a stand-in for quark--gluon plasma dynamics. This calibration serves as model validation and paves the way for utilizing TRENTo-3D as an initial-conditions model for state-of-the-art simulation incorporating (3+1)D relativistic viscous hydrodynamics.
nucl-th28 citations
08
IMSRG-Net: A machine learning-based solver for In-Medium Similarity Renormalization Group
Sota Yoshida
We present a novel method, IMSRG-Net, which utilizes machine learning techniques as a solver for the in-medium Similarity Renormalization Group (IMSRG). The primary objective of IMSRG-Net is to approximate the Magnus operators $Ω (s)$ in the IMSRG flow equation, thereby offering an alternative to the computationally intensive part of IMSRG calculations. The key idea of IMSRG-Net is its design of the loss function inspired by physics-informed neural networks to encode the underlying {\it physics}, i.e., IMSRG flow equation, into the model. Through training on a dataset comprising ten data points with flow parameters up to $s = 20$ , capturing approximately one-eighth to one-quarter of the entire flow, IMSRG-Net exhibits remarkable accuracy in extrapolating the ground state energies and charge radii of $^{16}$ O and $^{40}$ Ca. Furthermore, this model demonstrates effectiveness in deriving effective interactions for a valence space.
nucl-thphysics.comp-phPRC(2023)·3 citations
09
Revisiting the extraction of charge radii of $^{40}$ Ca and $^{208}$ Pb with muonic atom spectroscopy
Hui Hui Xie🇨🇳 · Tomoya Naito🇯🇵 · Jian Li🇨🇳 · Haozhao Liang🇯🇵
The extractions of nuclear charge radii from muonic atom spectroscopy for $^{40}$ Ca and $^{208}$ Pb are revisited to analyze the model dependencies induced by employing a Fermi-type charge distribution. For that, the charge densities, together with the corresponding muonic transition energies, calculated by the covariant density functional theory are used as a benchmark. The root-mean-square deviation of transition energies is calculated to quantitatively investigate the sensitivities of transition energies to the details of the two-parameter Fermi distribution. It is found that the second and fourth moments of the charge distribution can be extracted accurately from the muonic atom spectroscopy without much model dependencies, whereas the obtained two-parameter Fermi distributions cannot reproduce the details of the benchmarking charge densities and, in particular, its surface-diffuseness parameter cannot be determined accurately with the present experimental uncertainties on the muonic transition energies.
nucl-thnucl-exPLB(2023)·10 citations
10
Robust universal relations in neutron star asteroseismology
Deepak Kumar🇮🇳 · Tuhin Malik🇵🇹 · Hiranmaya Mishra🇮🇳 · Constança Providência🇵🇹
The non-radial oscillations of the neutron stars (NSs) have been suggested as a useful tool to probe the composition of neutron star matter (NSM). With this scope in mind, we consider a large number of equations of states (EOSs) that are consistent with nuclear matter properties and pure neutron matter EOS based on a chiral effective field theory (chEFT) calculation for the low densities and perturbative QCD EOS at very high densities. This ensemble of EOSs is also consistent with astronomical observations, gravitational waves in GW170817, mass and radius measurements from Neutron star Interior Composition ExploreR (NICER). We analyze the robustness of known universal relations (URs) among the quadrupolar $f$ mode frequencies, masses and radii with such a large number of EOSs and we find a new UR that results from a strong correlation between the $f$ mode frequencies and the radii of NSs. Such a correlation is very useful in accurately determining the radius from a measurement of $f$ mode frequencies in the near future. We also show that the quadrupolar $f$ mode frequencies of NS of masses 2.0 M $_{⊙}$ and above lie in the range $\sim$ 2-3 kHz in this ensemble of physically realistic EOSs. A NS of mass 2M $_{⊙}$ with a low $f$ mode frequency may indicate the existence of non-nucleonic degrees of freedom.
nucl-thastro-ph.HEgr-qchep-thPRD(2023)·13 citations
11
Non-Gaussian transverse momentum fluctuations from impact parameter fluctuations
Rupam Samanta🇵🇱 · João Paulo Picchetti🇧🇷 · Matthew Luzum🇧🇷 · Jean-Yves Ollitrault🇫🇷
The transverse momentum per particle, $[p_{t}]$ , fluctuates event by event in ultrarelativistic nucleus-nucleus collisions, for a given multiplicity. These fluctuations are small and approximately Gaussian, but a non-zero skewness has been predicted on the basis of hydrodynamic calculations, and seen experimentally. We argue that the mechanism driving the skewness is that, if the system thermalizes, the mean transverse momentum increases with impact parameter for a fixed collision multiplicity. We postulate that fluctuations are Gaussian at fixed impact parameter, and that non-Gaussianities solely result from impact parameter fluctuations. Using recent data on the variance of $[p_{t}]$ fluctuations, we make quantitative predictions for their skewness and kurtosis as a function of the collision multiplicity. We predict in particular a spectacular increase of the skewness below the knee of the multiplicity distribution, followed by a fast decrease.
nucl-thhep-exhep-phnucl-exPRC(2023)·24 citations
12
Interplay between non-interfering neutrino exchange mechanisms and nuclear matrix elements in $0 ν β β$ decay
Eligio Lisi🇮🇹 · Antonio Marrone🇮🇹 · Newton Nath🇮🇹
We revisit the phenomenology of neutrinoless double beta ( $0 ν β β$ ) decay mediated by non-interfering exchange of light and heavy Majorana neutrinos, in the context of current and prospective ton-scale experimental searches, as well as of recent calculations of nuclear matrix elements (NME) in different nuclear models. We derive joint upper bounds on the light and heavy contributions to $0 ν β β$ decay, for different sets of NME, through separate and combined data coming from the following experiments (and isotopes): KamLAND-Zen and EXO (Xe), GERDA, and MAJORANA (Ge) and CUORE (Te). We further consider three proposed projects that could provide, within current bounds, possible $0 ν β β$ decay signals at $> 3 σ$ level with an exposure of 10 ton years: nEXO (Xe), LEGEND (Ge) and CUPID (Mo). Separate and combined (Xe, Ge, Mo) signals are studied for different representative cases and NME sets, and the conditions leading to (non)degenerate light and heavy neutrino mechanisms are discussed. In particular, the role of heavy-to-light NME ratios in different isotopes is highlighted through appropriate graphical representations. By using different sets of "true" and "test" NME as a proxy for nuclear uncertainties, it is shown that the relative contributions of light and heavy neutrino exchange to $0 ν β β$ signals may be significantly biased in some cases. Implications for theoretical models connecting light and heavy Majorana neutrino masses are also briefly illustrated. These results provide further motivations to improve NME calculations, so as to better exploit the physics potential of future multi-isotope $0 ν β β$ searches at the ton scale.
↳ hep-phhep-exnucl-exnucl-thPRD(2023)·8 citations
13
Improving Euler-Heisenberg-Schwinger effective action with dressed photons
Stefan Evans🇺🇸 · Johann Rafelski🇺🇸
We implement a longstanding proposal by Weisskopf to apply virtual polarization corrections to the in/out external fields in study of the Euler-Heisenberg-Schwinger effective action. Our approach requires distinguishing the electromagnetic and polarization fields based on mathematical tools developed by Białynicki-Birula, originally for the Born-Infeld action. Our solution is expressed as a differential equation where the one-loop effective action serves as input. As a first result of our approach, we recover the higher-order one-cut reducible loop diagrams discovered by Gies and Karbstein.
↳ hep-phhep-thnucl-thquant-phActa Phys.Polon.A(2023)·4 citations
14
NNLL Resummation of Sudakov Shoulder Logarithms in the Heavy Jet Mass Distribution
Arindam Bhattacharya🇺🇸 · Johannes K. L. Michel🇺🇸 · Matthew D. Schwartz🇺🇸 · Iain W. Stewart🇺🇸 · Xiaoyuan Zhang🇺🇸
The heavy jet mass event shape has large perturbative logarithms near the leading order kinematic threshold at $ρ = \frac{1}{3}$ . Catani and Webber named these logarithms Sudakov shoulders and resummed them at double-logarithmic level. A resummation to next-to-leading logarithmic level was achieved recently. Here, we extend the resummation using an effective field theory framework to next-to-next-to-leading logarithmic order and show how to combine it with the resummation of dijet logarithms. We also solve the open problem of an unphysical singularity in the resummed momentum space distribution, in a way similar to how it is resolved in the Drell-Yan $q_{T}$ spectrum: through a careful analysis of the kinematics and scale-setting in position space. The heavy jet mass Sudakov shoulder is the first observable that does not involve transverse momentum for which position space resummation is critical. These advances may lead to a more precise extraction of the strong coupling constant from $e^{+} e^{-}$ data.
↳ hep-phnucl-thJHEP(2023)·18 citations
15
Lectures on Field Theory and the Standard Model: A Symmetry-Oriented Approach
Luis Alvarez-Gaume🇺🇸 · Miguel A. Vazquez-Mozo🇪🇸
The standard model of particle physics represents the cornerstone of our understanding of the microscopic world. In these lectures we review its contents and structure, with a particular emphasis on the central role played by symmetries and their realization. This is not intended to be an exhaustive review but a discussion of selected topics that we find interesting, with the specific aim of clarifying some subtle points and potential misunderstandings. A number of more technical topics are discussed in separated boxes interspersed throughout the text.
↳ hep-thgr-qchep-phnucl-thCERN Yellow Rep.School Proc.(2025)·1 citation
16
Radial and Non-Radial Oscillations of Inverted Hybrid Stars
Chen Zhang🇨🇳 · Yudong Luo🇨🇳 · Hong-bo Li🇨🇳 · Lijing Shao🇨🇳 · Renxin Xu🇨🇳
We study the radial and non-radial oscillations of Cross stars (CrSs), i.e., stars with a quark matter crust and a hadronic matter core in an inverted order compared to conventional hybrid stars. We draw comparisons of their oscillation modes with those of neutron stars, quark stars, and conventional hybrid stars. We find that the stellar stability analysis from the fundamental mode of radial oscillations, and the $g$ , $f$ modes of non-radial oscillations are quite similar to those of conventional hybrid stars. However, due to the inverted stellar structure, the first non-radial $p$ mode of CrSs behaves in an inverted way and sits in a higher frequency domain compared to that of conventional hybrid stars. These results provide a direct way to discriminate CrSs from other types of compact stars via gravitational-wave probes. Specifically, compact stars emitting $g$ -mode gravitational waves within the $0.5$ - $1$ kHz range should be CrSs or conventional hybrid stars rather than neutron stars or pure quark stars, and a further GW detection of the first $p$ mode above 8 kHz or an identification of a decreasing trend of frequencies versus star masses associated with it will help identify the compact object to be a CrS rather than a conventional hybrid star.
↳ astro-ph.HEastro-ph.SRgr-qchep-ph+1PRD(2024)·20 citations
17
$Q Q ˉ q q q$ Quark System, Compact Pentaquark, and Gauge/String Duality (Part II)
Oleg Andreev🇩🇪
This is the second of two companion papers in which we continue to develop the construction of the doubly heavy pentaquark systems using the gauge/string duality. In this paper, we propose a stringy description of the $Q Q ˉ q q q$ system in the case of two light flavors. Our goal is to explore the lower-lying Born-Oppenheimer potentials as a function of the separation distance between the heavy quark-antiquark pair. The analysis shows that the ground state Born-Oppenheimer potential is described in terms of both hadro-quarkonia and hadronic molecules. Meanwhile a standard pentaquark configuration, which describes a genuine five-quark interaction, makes the dominant contribution to a higher lying potential. This configuration has an antiquark-diquark-diquark structure $Q ˉ [q q] [Qq]$ for separations larger than $0.1 fm$ . The latter enables us to establish a relation among the masses of hadrons in the heavy quark limit. To describe the structure of the potentials more clear, we define some critical separations that are related to the processes of string reconnection, breaking and junction annihilation. Additionally, we consider the generalized baryon vertices, where more than three strings can meet, and explore their implications for the pentaquark systems.
↳ hep-phhep-lathep-thnucl-thPRD(2023)·7 citations
18
Transverse momentum spectra of $f_{0} (980)$ from coalescence model
An Gu🇺🇸 · Fuqiang Wang🇺🇸
We use a coalescence model to generate $f_{0}$ (980) particles for four configurations: $s s ˉ$ meson, $u u ˉ s s ˉ$ tetraquark, $K^{+} K^{-}$ molecule and $u u ˉ$ p-wave state. The phase-space information of the coalescing constituents is taken from a multi-phase transport (AMPT) simulation of proton-proton and proton-lead collisions at the LHC. It is shown that the transverse momentum spectra and production yields of $f_{0} (980)$ differ significantly among the configurations. It is suggested that the $p_{T}$ spectra of the $f_{0} (980)$ compared to those of other hadrons (such as pion) and the ratio of the $f_{0} (980)$ $p_{T}$ spectra in pPb over pp can be exploited to tell the configuration of the $f_{0} (980)$ .
↳ hep-phnucl-thPLB(2024)·3 citations
19
Higher Order Corrections to the Effective Field Theory of Low-energy Axions
Bryan Cordero-Patino🇪🇨 · Álvaro Duenas-Vidal🇪🇨 · Jorge Segovia🇪🇸
Dark matter (DM) can be composed of a collection of axions, or axion-like particles (ALPs), whose existence is due to the spontaneous breaking of the Peccei-Quinn $U (1)$ symmetry which is the most compelling solution of the strong $C P$ -problem of Quantum Chromodynamics (QCD). Axions must be spin- $0$ particles with very small masses and extremely weak interactions with themselves as well as with the particles that constitute the Standard Model. In general, the physics of axions is detailed by a quantum field theory of a real scalar field, $ϕ$ . Nevertheless, it is more convenient to implement a non-relativistic effective field theory with a complex scalar field, $ψ$ , to characterize the mentioned axions in the low-energy regime. A possible application of this equivalent description is to study the collapse of cold dark matter into more complex structures. There have been a few derivations of effective Lagrangians for the complex field $ψ$ ; resulting to be all equivalent after a nonlocal-space transformation between $ϕ$ and $ψ$ was found, and some other corrections were introduced. Our contribution herein is to further provide higher order corrections, in particular, we compute the effective field theory Lagrangian up to order $(ψ^{*} ψ)^{5}$ , incorporating also the fast-oscillating field fluctuations into the dominant slowly-varying non-relativistic field.
↳ hep-phhep-exhep-thnucl-ex+1Symmetry(2023)·1 citation
20
Shadow-based quantum subspace algorithm for the nuclear shell model
Ruyu Yang🇨🇳 · Tianren Wang🇨🇳 · Bing-Nan Lu🇨🇳 · Ying Li🇨🇳 · Xiaosi Xu🇨🇳
In recent years, researchers have been exploring the applications of noisy intermediate-scale quantum (NISQ) computation in various fields. One important area in which quantum computation can outperform classical computers is the ground state problem of a many-body system, e.g., the nucleus. However, using a quantum computer in the NISQ era to solve a meaningful-scale system remains a challenge. To calculate the ground energy of nuclear systems, we propose a new algorithm that combines classical shadow and subspace diagonalization techniques. Our subspace is composed of matrices, with the basis of the subspace being the classical shadow of the quantum state. We test our algorithm on nuclei described by Cohen-Kurath shell model and USD shell model. We find that the accuracy of the results improves as the number of shots increases, following the Heisenberg scaling.
↳ quant-phnucl-thPRA(2025)·9 citations
21
Universality of energy-momentum response in kinetic theories
Xiaojian Du🇪🇸 · Stephan Ochsenfeld🇩🇪 · Sören Schlichting🇩🇪
We study the response of the energy-momentum tensor in several kinetic theories, from the simple relaxation time approximation (RTA) to Quantum Chromodynamics (QCD). Irrespective of the differences in microscopic properties, we find a remarkable degree of universality in the response functions from conformal theories. We find that the response to scalar perturbations in kinetic theory can be effectively described by a pair of one hydrodynamic sound mode and one non-hydrodynamic mode. We find that even beyond the range of validity of hydrodynamics, the energy-momentum response in position space can be effectively described by one single mode with non-trivial dispersion relation and residue.
↳ hep-phnucl-thPLB(2023)·13 citations
22
Theory of heavy-quarks contribution to the quark-gluon plasma viscosity
Alessio Zaccone🇮🇹
The shear viscosity of quark gluon plasma is customarily estimated in the literature using kinetic theory, which, however, is well known to break down for dense interacting systems. Here we propose an alternative theoretical approach based on recent advances in the physics of dense interacting liquid-like systems, which is valid for strongly-interacting and arbitrarily dense relativistic systems. With this approach, the viscosity of strongly interacting dense heavy-quarks plasma is evaluated analytically, at the level of special relativity. For QGP well above the confinement temperature, the theory predicts that the viscosity increases with the cube of temperature, in agreement with evidence.
↳ hep-phcond-mat.stat-mechhep-latnucl-thNPB(2024)·5 citations
23
QCD resummation of dijet azimuthal decorrelations in pp and pA collisions
Mei-Sen Gao🇨🇳 · Zhong-Bo Kang🇺🇸 · Ding Yu Shao🇨🇳 · John Terry🇺🇸 · Cheng Zhang🇨🇳
We study the azimuthal angular decorrelations of dijet production in both proton-proton (pp) and proton-nucleus (pA) collisions. By utilizing soft-collinear effective theory, we establish the factorization and resummation formalism at the next-to-leading logarithmic accuracy for the azimuthal angular decorrelations in the back-to-back limit in pp collisions. We propose an approach where the nuclear modifications to dijet production in pA collisions are accounted for in the nuclear modified transverse momentum dependent parton distribution functions (nTMDPDFs), which contain both collinear and transverse dynamics. This approach naturally generalizes the well-established formalism related to the nuclear modified collinear parton distribution functions (nPDFs). We demonstrate strong consistency between our methodology and the CMS measurements in both pp and pA collisions, and make predictions for dijet production in the forward rapidity region in pA collisions at LHC kinematics and for mid-rapidity kinematics at sPHENIX. Throughout this paper, we focus on the application of this formalism to a simultaneous fit to both collinear and transverse momentum dependent contributions to the transverse momentum dependent distributions.
↳ hep-phhep-exnucl-exnucl-thJHEP(2023)·18 citations

Affiliations

first authorsco-authorsvia INSPIRE