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Though being seemingly disparate and with relatively new intersection, high energy nuclear physics and machine learning have already begun to merge and yield interesting results during the last few years. It's worthy to raise the profile of utilizing this novel mindset from machine learning in high energy nuclear physics, to help more interested readers see the breadth of activities around this intersection. The aim of this mini-review is to introduce to the community the current status and report an overview of applying machine learning for high energy nuclear physics, to present from different aspects and examples how scientific questions involved in high energy nuclear physics can be tackled using machine learning.

Nuclear symmetry energy $E_{\mathrm{sym}}(ρ)$ encoding the cost to make nuclear matter more neutron rich has been the most uncertain component of the EOS of dense neutron-rich nucleonic matter. It affects significantly the radii, tidal deformations, cooling rates and frequencies of various oscillation modes of isolated neutron stars as well as the strain amplitude and frequencies of gravitational waves from their mergers, besides its many effects on structures of nuclei as well as the dynamics and observables of their collisions. Siemens (1970s) observed that $E_{\mathrm{sym}}(ρ)$ scales as $(ρ/ρ_0)^{2/3}$ near the saturation density $ρ_0$ of nuclear matter, since both the kinetic part and the potential contribution (quadratic in momentum) exhibit this dependence. The scaling holds if: (1) the nucleon isoscalar potential is quadratic in momentum, and (2) the isovector interaction is weakly density dependent. After examining many empirical evidences and understanding theoretical findings in the literature we conclude that: (1) Siemens' $ρ^{2/3}$ scaling is robust and serves as a valuable benchmark for both nuclear theories and experiments up to $2ρ_0$ but breaks down at higher densi

Adequate description of electro and gamma nuclear physics is of utmost importance in studies of electron beam-dumps and intense electron beam accelerators. I also is mandatory to describe neutron backgrounds and activation in linear colliders. This physics was elaborated in Geant4 over the last year, and now entered into the stage of practical application. In the {\sc Geant4} Photo-nuclear data base there are at present about 50 nuclei for which the Photo-nuclear absorption cross sections have been measured. Of these, data on 14 nuclei are used to parametrize the gamma nuclear reaction cross-section The resulting cross section is a complex, factorized function of $A$ and $e = log(E_γ)$, where $E_γ$ is the energy of the incident photon. Electro-nuclear reactions are so closely connected with Photo-nuclear reactions that sometimes they are often called ``Photo-nuclear''. The one-photon exchange mechanism dominates in Electro-nuclear reactions, and the electron can be substituted by a flux of photons. Folding this flux with the gamma-nuclear cross-section, we arrive at an acceptable description of the electro-nuclear physics. Final states in gamma and electro nuclear physics are descr

The nuclear symmetry energy characterizes the variation of the binding energy as the neutron to proton ratio of a nuclear system is varied. This is one of the most important features of nuclear physics in general, since it is just related to the two component nature of the nuclear systems. As such it is one of the most relevant physical parameters that affect the physics of many phenomena and nuclear processes. This review paper presents a survey of the role and relevance of the nuclear symmetry energy in different fields of research and of the accuracy of its determination from the phenomenology and from the microscopic many-body theory. In recent years, a great interest was devoted not only to the Nuclear Matter symmetry energy at saturation density but also to its whole density dependence, which is an essential ingredient for our understanding of many phenomena. We analyze the nuclear symmetry energy in different realms of nuclear physics and astrophysics. In particular we consider the nuclear symmetry energy in relation to nuclear structure, astrophysics of Neutron Stars and supernovae, and heavy ion collision experiments, trying to elucidate the connections of these different

There are profound connections between neutrino physics and nuclear experiments. Exceptionally precise measurements of single and double beta-decay spectra illuminate the scale and nature of neutrino mass and may finally answer the question of whether neutrinos are their own antimatter counterparts. Neutrino-nucleus scattering underpins oscillation experiments and probes nuclear structure, neutrinos offer a rare vantage point into collapsing stars and nuclear fission reactors, and techniques pioneered in neutrino nuclear-physics experiments are advancing quantum-sensing technologies. In this article, we review current and planned efforts at the intersection of neutrino and nuclear experiments.

In this paper we introduce the energy efficiency as a new metric for evaluating both hardware platforms based on Graphic Processor Units (GPU), and algorithm optimisations at High Energy Physics (HEP) experiments. We develop a method to compute the energy efficiency for the case of the first high level trigger (HLT1) of the LHCb experiment, relating the throughput with GPU specifications such as the number of cores, clock frequency, memory bandwidth and thermal design power. The model can be extended to other HEP experiments to make decisions and reach sustainable computing ecosystems.

The high-density behavior of nuclear symmetry energy is among the most uncertain properties of dense neutron-rich matter. Its accurate determination has significant ramifications in understanding not only the reaction dynamics of heavy-ion reactions especially those induced by radioactive beams but also many interesting phenomena in astrophysics, such as the explosion mechanism of supernova and the properties of neutron stars. The heavy-ion physics community has devoted much effort during the last few years to constrain the high-density symmetry using various probes. In particular, the pion-/pion+ ratio has been most extensively studied both theoretically and experimentally. All models have consistently predicted qualitatively that the pion-/pion+ ratio is a sensitive probe of the high-density symmetry energy especially with beam energies near the pion production threshold. However, the predicted values of the pion-/pion+ ratio are still quite model dependent mostly because of the complexity of modeling pion production and reabsorption dynamics in heavy-ion collisions, leading to currently still controversial conclusions regarding the high-density behavior of nuclear symmetry energ

In these three lectures I discuss the present status of high-energy astroparticle physics including Ultra-High-Energy Cosmic Rays (UHECR), high-energy gamma rays, and neutrinos. The first lecture is devoted to ultra-high-energy cosmic rays. After a brief introduction to UHECR I discuss the acceleration of charged particles to highest energies in the astrophysical objects, their propagation in the intergalactic space, recent observational results by the Auger and HiRes experiments, anisotropies of UHECR arrival directions, and secondary gamma rays produced by UHECR. In the second lecture I review recent results on TeV gamma rays. After a short introduction to detection techniques, I discuss recent exciting results of the H.E.S.S., MAGIC, and Milagro experiments on the point-like and diffuse sources of TeV gamma rays. A special section is devoted to the detection of extragalactic magnetic fields with TeV gamma-ray measurements. Finally, in the third lecture I discuss Ultra-High-Energy (UHE) neutrinos. I review three different UHE neutrino detection techniques and show the present status of searches for diffuse neutrino flux and point sources of neutrinos.

High-energy collisions involving the $A=96$ isobars $^{96}$Zr and $^{96}$Ru have been performed in 2018 at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) as a means to search for the chiral magnetic effect in QCD. This would manifest itself as specific deviations from unity in the ratio of observables taken between $^{96}$Zr+$^{96}$Zr and $^{96}$Ru+$^{96}$Ru collisions. Measurements of such ratios (released at the end of 2021) indeed reveal deviations from unity, but these are primarily caused by the two collided isobars having different radial profiles and intrinsic deformations. To make progress in understanding RHIC data, nuclear physicists across the energy spectrum gathered in Heidelberg in 2022 as part of an EMMI Rapid Reaction Task Force (RRTF) to address the following question. Does the combined effort of low-energy nuclear structure physics and high-energy heavy-ion physics enable us to understand the observations made in isobar collisions at RHIC?

We review the charged particle and photon multiplicity, and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at different collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons and the transverse energy measurement.

The Canadian subatomic physics community establishes its scientific, and thus funding, priorities through periodic Long-Range Plans (LRP). The community is now putting together a new LRP, which will be in effect from 2027 through 2034, with its scope extending through 2041. As part of this process, the Canadian Institute of Nuclear Physics (CINP) has put together a strategic report, following an extensive consultation process. The report describes the broad and ambitious research program undertaken by the Canadian nuclear physics research community, both onshore and abroad, touching on key questions regarding the origin, evolution, and structure of visible matter in the universe. This document provides a grid of different Canadian nuclear physics projects undertaken now and in the future, and their associated timelines. It concludes with specific recommendations for maximizing Canadian scientific output in nuclear physics.

We review recent results of net-proton multiplicity fluctuations from STAR experiment, aiming to locate the QCD critical point in high-energy nuclear collisions at RHIC. We show net-proton number cumulant and proton number factorial cumulant ratios up to fourth order using experimental data from RHIC BES-II Au+Au collisions in collider mode and fixed-target mode. The comparison is made between experimental data and non-critical model calculations from Lattice QCD, HRG, hydrodynamic simulations and transport model UrQMD. In addition, we discuss initial volume fluctuation effect, which plays significant role in fixed-target energies. Finally, an outlook on experimental research on the QCD critical point in future experiments will be presented.

We provide a pedagogical review of the Schwinger effect, i.e., the non-perturbative production of particle and anti-particle pairs from the vacuum by strong fields, as well as related strong-field phenomena. Beginning with an overview of the Schwinger effect in quantum electrodynamics, we discuss its extensions to quantum chromodynamics and its applications in nuclear physics, including high-$Z$ nuclei, string breaking, relativistic heavy-ion collisions, and the chiral anomaly.

The Relativistic Heavy Ion Collider at BNL has been exploring the energy frontier of nuclear physics since 2001. Its performance, flexibility and continued innovative upgrading can sustain its physics output for years to come. Now, the Large Hadron Collider at CERN is about to extend the frontier energy of laboratory nuclear collisions by more than an order of magnitude. In the coming years, its physics reach will evolve towards still higher energy, luminosity and varying collision species, within performance bounds set by accelerator technology and by nuclear physics itself. Complementary high-energy facilities will include fixed-target collisions at the CERN SPS, the FAIR complex at GSI and possible electron-ion colliders based on CEBAF at JLAB, RHIC at BNL or the LHC at CERN.

Data from high-energy physics (HEP) experiments are collected with significant financial and human effort and are in many cases unique. At the same time, HEP has no coherent strategy for data preservation and re-use, and many important and complex data sets are simply lost. In a period of a few years, several important and unique experimental programs will come to an end, including those at HERA, the b-factories and at the Tevatron. An inter-experimental study group on HEP data preservation and long-term analysis (DPHEP) was formed and a series of workshops were held to investigate this issue in a systematic way. The physics case for data preservation and the preservation models established by the group are presented, as well as a description of the transverse global projects and strategies already in place.

Based on the intermediate energy radioactive Ion Beam Line in Lanzhou (RIBLL) of Heavy Ion Research Facility in Lanzhou (HIRFL) and Low Energy Radioactive Ion Beam Line (GIRAFFE) of Beijing National Tandem Accelerator Lab (HI13), the radioactive ion beam physics and nuclear astrophysics will be researched in detail. The key scientific problems are: the nuclear structure and reaction for nuclear far from $β$-stability line; the synthesize of new nuclides near drip lines and new super heavy nuclides; the properties of asymmetric nuclear matter with extra large isospin and some nuclear astro- reactions.

This paper is essentially a verbatim reconstruction of lectures that I gave at the Los Alamos School on Relativistic Dynamics and Quark Nuclear Physics in 1985. They were published in the school proceedings, but the book is not widely available. The Los Alamos School took place at the height of the first wave of interest in the quark substructure of nuclei, stimulated by the 1983 discovery of the EMC Effect. Interest in this subject has been increasing for years and the prospect of a dedicated Electron Ion Collider within the decade guarantees even greater attention to quarks and gluons in nuclei among both theorists and experimentalists. Recently, to my surprise, I learned that copies of my old lectures have been circulating and been found useful by the relatively few people who know about them. The are, of course, dated: experiments have far outstripped what was available 37 years ago and theory has progressed too. However, the rest frame derivation of the parton model, the derivation and discussion of the convolution formalism for nucleons, nucleon correlations, and other, virtual, constituents of nuclei, and sections on scaling violation and the operator product expansion have

Using a transport model coupled with a phase-space coalescence after-burner we study the triton-3He relative and differential transverse flows in semi-central 132Sn+124Sn reactions at a beam energy of 400 MeV/nucleon. We find that the triton-3He pairs carry interesting information about the density dependence of the nuclear symmetry energy. The t-3He relative flow can be used as a particularly powerful probe of the high-density behavior of the nuclear symmetry energy.

This is a collection of perspective pieces contributed by the participants of the Institute of Nuclear Theory's Program on Nuclear Physics for Precision Nuclear Physics which was held virtually from April 19 to May 7, 2021. The collection represents the reflections of a vibrant and engaged community of researchers on the status of theoretical research in low-energy nuclear physics, the challenges ahead, and new ideas and strategies to make progress in nuclear structure and reaction physics, effective field theory, lattice QCD, quantum information, and quantum computing. The contributed pieces solely reflect the perspectives of the respective authors and do not represent the viewpoints of the Institute for Nuclear theory or the organizers of the program.