The critical questions posed by the 2023 Nuclear Science Long Range Plan include "how are the various hadrons produced in a single scattering process correlated to one another", and "how does hadronization change in a dense partonic environment?".
The results we present in this talk on azimuthal correlations in $\pi^+\pi^-$ and $\pi^+p$ pairs measured by the CLAS collaboration at Jefferson...
Studying the in-medium stimulated effects entails improving the experimental methods to probe the confinement dynamics of quarks and gluons, the building blocks of atomic nuclei. Therefore, the deeper one looks, the more perplexing the strongly interacting particles, namely hadrons, behave. Unraveling this behavior, as described by quantum chromodynamics (QCD), the theory of strong...
Understanding the confinement dynamics of quarks and gluons, the building blocks of atomic nuclei, remains a prime challenge in modern subatomic physics.~This investigation could be carried out by studying hadronization processes, particularly in the nuclear medium, where medium-stimulated effects such as hadron attenuation and transverse momentum broadening can be probed, providing critical...
Nuclear Short Range Correlations (SRCs) are pairs of nucleons that exist at short relative distances and high relative momenta within the nucleus. These SRC pairs significantly impact nuclear structure and have been extensively studied using hard quasi-elastic electron-scattering data. Interpretation of these data rely on our understanding of the reaction mechanisms in electron scattering as...
The nucleon-nucleon interaction at short distances is the primary mechanism responsible for generating high-momentum components in nucleon momentum distributions. The isospin structure and abundance of 2-nucleon short-range correlations (2N SRCs) have been studied in detail in both light and heavy nuclei. Additionally, theoretical models predict that 3N SRCs will emerge and become dominant at...
The modification of bound nucleon structure function in nuclei, known as the EMC Effect, was first observed over 40 years ago through Deep Inelastic Scattering (DIS) ratios comparing deuterium to other nuclei. Despite extensive study, the underlying mechanism behind this effect remains unresolved. A prominent hypothesis attributes the EMC Effect primarily to the modification of high-virtuality...
The upcoming EIC will allow us to study in depth the three-dimensional tomography of hadrons via Generalized Parton Distributions (GPDs). Recently, the 𝑥-dependence of GPDs have been found to be extracted from the lattice utilizing matrix elements of nonlocal operators. In this presentation we discuss results on the transversity GPDs utilizing novel theoretical developments of lattice QCD to...
We present recent results and future outlook for gluon parton distributions from lattice QCD, focusing primarily on the pion and nucleon gluon parton distribution functions (PDFs). The nucleon gluon PDF is a crucial input to the prediction of rare physics processes such as Higgs and $J/\psi$ production and beyond the standard model physics. The pion gluon PDF is expected to hold clues about...
In this presentation, I will show how the difference of interacting and non-interacting integrated two-particle correlation functions in finite volume is related to infinite volume scattering phase shift through an integral weighted by a factor exp(-Et). The difference of integrated finite volume correlation functions converge rapidly to its infinite volume limit as the size of periodic box is...
In this paper, we investigate an inflation scenario and dark energy in a scaled gravity, R + βR where β is a dimensionless gravity parameter, with a kinetic term. To reduce the associated moduli space, we implement such a parameter in a specific scalar potential given by V (ϕ) = M4(1 − (ϕ μ)β). By computing the relevant cosmological observables including the spectral index ns and the...
In ultraperipheral heavy-ion collisions (UPCs), vector meson photoproduction, e.g. $\rho^{0}$ and $J/\psi$, has been considered one of the most sensitive probes for studying the gluonic structure in heavy nuclei. The linear polarization of the photons involved in these processes can help to image the nucleus through the spin interference effect in vector meson photoproduction. Many efforts...
The LHCb experiment is a unique tool for studying ultra-peripheral heavy-ion collisions (UPCs) at the LHC. The LHCb spectrometer's forward acceptance provides sensitivity to extremely low-momentum partons in the nucleus and allows for the reconstruction of low-mass resonances produced in UPCs. Furthermore, LHCb's particle identification capabilities allow for the study of a wide range of final...
The study of $\rm{J}/\psi$ photoproduction in ultra-peripheral collisions (UPCs) offers a powerful probe of gluon dynamics in heavy nuclei. In UPCs, photons can interact with the nucleus coherently (involving the entire nucleus) or incoherently (with individual constituents). While coherent processes provide insight into the average gluon density, incoherent photoproduction is uniquely...
In this talk, we present the first measurement of $\mathrm{D}^0$ photoproduction in heavy ion ultraperipheral collisions (UPCs) using the data collected by CMS experiment during 2023 PbPb collisions at LHC. The measured production cross sections are presented as a function of the $\mathrm{D}^0$ transverse momentum (2<p$_T$<12 GeV/c) and rapidity (-2<y<2). The results are compared to...
The emergence and evolution of collective behavior in small collision systems remains a key area of interest in high-energy nuclear physics. To understand how collectivity evolves with system size RHIC has conducted a dedicated small system scans, including He$^3$+Au, d+Au, and p+Au collisions.
In 2021, the STAR collaboration expanded the scan by introducing a symmetric yet small system...
The dominant interaction between a heavy quark and antiquark at low energy is described through the static potential. The real part of the potential becomes screened with a screening mass proportional to the temperature, and the imaginary part of the potential gives bound-states a non-zero width. As the temperature increases bound-states can disappear either because they are not supported by...
Exclusive vector-meson production in e+A collisions has been suggested as a probe to analyze the distribution of gluons within the nucleus. However, the Good-Walker paradigm implies that coherent exclusive events probe the spatial distribution of the nucleons, whereas incoherent exclusive interactions are sensitive to event-by-event fluctuations within the nucleus. Consequently, any photons...
Backward, or $u$-channel, production of mesons in $ep$ collisions results in a nearly-stopped proton and a meson with a large forward momentum. In conventional (forward, $t$-channel) production, the momentum transfer from the proton to the meson is small and is modeled by pomeron-exchange trajectories. These $t$-channel production cross sections can be transformed into target density...
Directed flow of particles is an important feature seen in heavy-ion collisions and is a
sensitive probe of the equation of state (EoS) of the matter produced in the collisions.
Model calculations have also predicted that directed flow could be a sensitive probe of the
softening of the EoS associated with a first order phase transition. Directed flow of protons
and anti-protons are also of...
Currently, the nature of the baryon number carrier remains debated. Although it is conventionally assumed to be carried by quarks, an alternative model suggests that the baryon number is instead carried by a Y-shaped gluon configuration called the baryon junction. This has significant ramifications for baryon emission at mid-rapidity in nuclear collisions. In this work, we accurately extract...
