A priori, nothing prohibits the existence of exotic hadrons in QCD. However, for the particular case of elusive pentaquarks, more than fifty years of experimental research ended up being inconclusive, leaving the scientific community wondering if they really exist. The LHCb Collaboration announcement on the two new pentaquark states with heavy quark content in 2015 revived the interest in the...
Relativistic heavy-ion collisions produce loosely bound hadronic molecules at a rate that is surprising large, since the molecules seem to emerge from a hadron gas whose temperature is orders of magnitude larger than their binding energies. These molecules have been referred to as "snowballs in hell". Their production has been explained in terms of a novel thermodynamic variable conjugate to...
We develop parameterizations of 8 of the lowest Born-Oppenheimer potentials for quarkonium
hybrid mesons as functions of the separation r of the static quark and antiquark sources. The
parameters are determined by fitting results calculated using pure SU(3) lattice gauge theory.
The parameterizations have the correct limiting behavior at small r, where the potentials form
multiplets...
The abundance of exotic hadron candidates has driven a global effort to understand their emergence from hadronic interactions and QCD dynamics. The Exotic Hadron Collaboration (ExoHad) explores all aspects of exotic hadron physics, from predictions within lattice QCD, through reliable extraction of their existence and properties from experimental data, to descriptions of their structure within...
Multiple approaches attempt to describe hard and semi-hard scattering processes in p+A-style collisions. One approach is based on leading-twist pQCD in a collinear factorization picture, where all initial and final state effects on hard processes are included within a set of nuclear parton density functions (nPDFs) universal in x and Q^2. Other approaches are based on a dynamical description...
Since baryon is a composite particle, one may wonder which degrees of freedom are carrying the conserved charges, including the baryon number. A baryon junction, that arises naturally in a gauge-invariant description of the baryon wavefunction, is a perfect candidate to associate the baryon number with. In this talk I will discuss various possibilities to test the flow of baryon number...
The CMS experiment has conducted extensive research in heavy flavor spectroscopy, revealing significant findings in both exotic hadron production and traditional hadron decays. Recent results include the first evidence for the production of the exotic state (X(3872)) in heavy-ion collisions, providing new insights into its internal structure and production mechanisms. Additionally, new...
The possible link between entanglement and thermalization, and the dynamics of hadronization are addressed by studying the real-time response of the massive Schwinger model coupled to external sources. This setup mimics the production and fragmentation of quark jets, as the Schwinger model and QCD share the properties of confinement and chiral symmetry breaking. By using quantum simulations on...
Jet substructure is a powerful tool for performing fundamental QCD tests in elementary particle collisions and offers unique insight into the microscopic structure of the QGP in heavy-ion collisions. Defined as the energy-weighted cross section of particle pairs inside jets, the two-point energy-energy correlator (EEC) is a novel jet substructure observable probing the correlation of energy...
This talk presents the first measurement of low-transverse-momentum ($p_T$) charged-hadron distributions in pseudorapidity and azimuthal angle, relative to the momentum direction of $Z$ bosons, in lead-lead ($\mathrm{PbPb}$) collisions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_\mathrm{NN}} = 5.02$ TeV. The analysis uses PbPb data from 2018 with an integrated luminosity of $1.67...
We calculate the subeikonal corrections to the differential cross-section of inclusive and incoherent diffractive dijet production in DIS using the background field method. In contrast to the existing studies, we perform the calculation without assuming finite support of the background field. The next order corrections not only arise from the expansion of the phases, which accounts for the...
Measuring jet substructure at the Large Hadron Collider provides exciting new opportunities to study detailed aspects of QCD dynamics. Comprehensive jet substructure measurements in proton collisions have played a critical role in mapping the multi-scale evolution of jets. Jet substructure measurements in heavy flavor jets have even led to the direct observation of the suppression of collinear...
A TeV muon-ion collider could be established if a high energy muon beam that is appropriately cooled and accelerated to the TeV scale is brought into collision with a high energy hadron beam at facilities such as Brookhaven National Lab, Fermilab, or CERN. Such a collider opens up a new regime for deep inelastic scattering studies at unprecedented small Bjorken-$x$ and high Q$^{2}$, as well as...
The shapes of colliding nuclei influence flow patterns in heavy-ion collisions due to hydrodynamic responses to collision geometry. We performed simulations to study the impact of nuclear structure on anisotropic flow ratios in Pb+Pb and Xe+Xe collisions at the LHC. Our findings show these ratios are significantly affected by nuclear structure, offering a new method to probe deformed nuclear...
Ultrarelativistic isobar collisions serve as a powerful tool for probing nuclear structures. These high-energy collisions are typically described by a hydrodynamic expansion, preceded by a pre-thermal equilibrium phase. However, due to the computational complexity of hydrodynamic simulations, studies of isobar nuclear structures often rely on geometrical estimators, such as eccentricities,...
Nuclear spectroscopy with heavy ion beams and fixed targets has emerged as a powerful tool for studying sub-atomic nuclei with strangeness, known as hypernuclei. Recent experiments using high-energy heavy ion beams have challenged the current understanding of light hypernuclei [1,2,3,4,5,6,7,8], particularly the hypertriton which is a subject of ongoing debate in the field, often referred to...
A number of new four-quark states containing from one to four $c$ or $\overline c$ quarks have been observed recently. Many of these new states have been discovered at the LHC. The production of these states via intrinsic charm in the proton is investigated. The tetraquark masses obtained in this approac agree well with the measured masses [1]. These calculations can provide some insight...
We present a comprehensive study of bottomonium ($\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$) suppression in minimum-bias proton-Lead ($p$-Pb) collisions at 5.02 and 8.16 TeV. Our approach accounts for both cold nuclear matter (CNM) effects (nuclear parton distribution function (nPDF) effects, coherent energy loss and momentum broadening), and hot nuclear matter (HNM) effect due to the...
The proposed Electron-Ion Collider (EIC) will utilize high-luminosity high-energy electron+proton ($e+p$) and electron+nucleus ($e+A$) collisions at different center of mass energies to solve several fundamental questions in the nuclear physics field. Due to their high masses ($M_{c,b} > \Lambda_{QCD}$), heavy quarks are produced early in hard partonic scatterings and their flavors are...
In this talk, we will summarize the goals of the workshop held at Stony Brook University (CFNS) in January 2025, which focused on advancing our understanding of cold nuclear matter (CNM) effects in hadron-nucleus (h+A) collisions. We will explore the challenges of applying perturbative Quantum Chromodynamics (pQCD) to h+A collisions, particularly the complexities arising from CNM effects such...
One of the best ways to understand hadronization in QCD is to study the production of quarkonium. The color evaporation model (CEM) and Nonrelativistic QCD (NRQCD) can describe production yields rather well but spin-related measurements like the polarization are stronger tests. In this talk, we will present the first expansion of the improved CEM into electron-proton collisions, and the...
Artificial intelligence and machine learning techniques have gained increasing attention in recent years as powerful tools for advancing data analysis and simulations across various fields of physics. Among these, generative models are notable for their ability to create complex data distributions, with Generative Adversarial Networks (GANs) already showing promise in reducing the...
In the aftermath of a high energy non-central heavy-ion collision, it is expected that along a quark-gluon plasma (QGP) a very strong electromagnetic field is produced. To characterize the strength of such a field, it has been theorized that it can induce measurable effects on the width and leptonic invariant mass of the Z-boson, with the effect being maximal for semi-central collisions. We...
The Relativistic Heavy Ion Collider (RHIC) has been in operation since 2001, contributing significantly to the study of strong interactions and nuclear matter under extreme conditions. The PHENIX experiment, operated from 2001 to 2016, has collected a comprehensive dataset that continues to yield impactful results with heavy flavor probes. These measurements have provided critical insights...
