Since Dirac proposed the light-front form of the relativistic dynamics in 1949, the ILCAC put together a white paper entitled "Light-front Quantum Chromodynamics" (LFQCD) as a framework for the analysis of hadron physics in 2013. Its goal was to find solutions that describe hadrons in the theory of strong interactions, QCD. Many progresses have been made toward the specific goals of this...
We propose a new class of exclusive processes for extracting generalized parton distribution functions (GPDs), which provide a powerful theoretical tool to quantify the spatial distribution of quarks and gluons inside a bound hadron. Using exclusive massive-photon-pair production in meson-meson and meson-baryon collisions as an example, we show that the leading non-perturbative contribution to...
I will discuss some new developments in hadron physics which can be derived from light-front holography and superconformal quantum mechanics. This includes new insights into the physics of color confinement, chiral symmetry, the spectroscopy and dynamics of hadrons, as well as surprising supersymmetric relations between the masses and light-front wavefunctions of mesons, baryons, and...
Light-front quantization focuses on a particular type of modes in full QCD, the soft and collinear modes in a pre-selected direction, which are useful to describe the quark and gluon structure of the hadrons traveling at the speed of light in the direction. The standard approach to obtain the Hamiltonian and Feynman rule is to take the infinite momentum limit before imposing a UV cut-off, a...
Basis Light Front Quantization (BLFQ) has been successfully applied to obtain bound states in both QED and QCD. For QCD applications in limited Fock spaces, one assumes a form of confinement based on light-front holography along with an additional longitudinal confinement. Recent applications include expanding Fock spaces beyond valence fermions to include the dynamical gauge degrees of...
We present recent results from the JAM (Jefferson Lab Angular Momentum) Collaboration's global QCD analysis of pion parton distributions. In particular, we assess the impact of threshold resummation on the behavior of the pion's valence distributions at large parton momentum fractions x.
In hypernuclear physics, during two decade, we have been obtaining many epoch-making data which are related to information on hyperon-nucleon and hyperon-hyperon interactions. In this talk, I will introduce the recent progress and future prospect at J-PARC in hypernuclear physics from theory side.
I will update the progress on the determination of nucleon parton distributions on the lattice using the large momentum effective field theory approach.
An exact computation of effective Hamiltonians in an elementary model akin to quantum field theory is carried out by solving equations of the renormalization group procedure for effective particles (RGPEP) [1]. The computation exhibits the mechanism by which the weak-coupling expansion and Tamm-Dancoff approximation increase in accuracy along the RGPEP evolution. The model computational...
The spectrum and structure of nucleon resonances are investigated analyzing pion, photon and electron induced meson production reactions. The understanding of the GeV lepton induced reaction and of the role of resonances plays important for the long base line neutrino oscillation experiments [1]. In this talk, resonance poles in coupled channel system is discussed [2] using the uniformized...
We review and revisit the concept of charge distribution in the relativistic context. Adopting a phase-space perspective allows us to discuss the momentum dependence of these distributions and to connect the well-known pictures in both the Breit frame and the infinite-momentum frame. In particular, we explain why the center of the neutron charge distribution appears to be negative in the...
In the literature concerning the Generalized Parton (GPDs) distributions of $^4$He, the common opinion is that a single GPD is dominant at high values of the virtuality $Q$. Because the Compton form factors (CFFs) are related to the GPDs by sum rules, this implies that a single CFF must be dominant at high $Q$ and that the data can be safely analyzed in terms of this CFF. In the present study,...
The Facility for Antiproton and Ion Research, FAIR, is under construction near Darmstadt, Germany. Among other large-scale installations, the PANDA (Antiproton annihilations in Darmstadt) experiment is designed to answer pressing questions in the charmonium mass region. At PANDA, an antiproton beam with momenta up to 15 GeV/c circulating in the high-energy storage ring HESR will interact with...
I will present a selection of results from the COMPASS experiment at CERN. They cover measurements related to the nucleon spin and structure, obtained from deep inelastic scattering (DIS) of muons on longitudinally and transversely polarized nucleons, as well as unpolarized hydrogen. The 3D structure of the nucleon is also studied via exclusive reactions: deep virtual Compton scattering...
Bound states are perturbatively expanded in the coupling $\alpha$ around lowest order bound states, not around free states as for scattering amplitudes. The expansion is not unique, as bound state wave functions are non-polynomial in $\alpha$ even in a first approximation. I describe a first-principles, equal-time method based on a Fock expansion where the constituents are bound by the...
Charged pions obviously carry no baryon number. Nevertheless, they possess a nontrivial baryonic structure stemming from isospin breaking by the $u$ and $d$ quark mass difference and from the EM effects. We obtain estimates for the pion baryonic form factor in two very different ways ways: from simple constituent quark models, and from vector meson dominance fits to the experimental $e^+ e^-...
The science program enabled by the Solenoidal Large Detector Device (SoLID) in Hall A at Jefferson Lab encompasses studies of nucleon structure addressing some of the fundamental questions in hadron structure. It will explore the nucleon origins of mass and spin in the framework of Quantum Chromodynamics at the luminosity frontier. It will also seek signatures of physics beyond the standard...
The quark-gluon dynamics manifests itself in a set of non-perturbative functions describing all possible spin-spin and spin-orbit correlations. Single and Dihadron semi-inclusive and hard exclusive production, both in current and target fragmentation regions, provide a variety of spin and azimuthal angle dependent observables, sensitive to the dynamics of quark-gluon interactions. Studies...
Understanding the origin of the EMC effect - the modification of the internal structure of nucleons bound in nuclei - is an ongoing effort in QCD research with far-reaching implications for our understanding of the fundamental structure of matter. Inclusive measurements have characterized many features of the EMC effect, but are insensitive to the initial state of the nucleus and therefore...
We may anticipate that future accelerator facilities will include the possibility of energetic twisted photons, which are photons with a structured wave front that can allow a pre-defined large angular momentum along the beam direction. Twisted photons are potentially a new tool in hadronic physics, and we consider here the possibility of selective photoproduction of higher-spin baryons using...
Usual three-dimensional (3D) densities of the nucleon are only meaningful quasi-probabilistically through the Wigner distributions. Taking the infinite-momentum frame, where the nucleon is on the light cone, we can define two-dimensional (2D) distributions of the nucleon, which contain the quantum-mechanically probabilistic meaning. The Abel transformations, on the other hand, allow one to...
There are new polarized structure functions, which do not exist for the spin-1/2 nucleons, in a spin-1 hadron such as the deuteron. In the charged-lepton deep inelastic scattering, the new leading-twist structure functions are $b_1$ and $b_2$, which are related by the Callan-Gross type relation $b_2 = 2 x b_1$ in the Bjorken scaling limit. There exists a parton-model sum rule for $b_1$ [1]. We...
The positronium is arguably the simplest bound state in QED. It is often used as a model for studying the structure of hadrons. In this talk, I will report our recent progress in solving the structure of the positronium from the light-front QED Hamiltonian in a basis approach. We include one dynamic photon in the basis. We perform the nonperturbative mass renormalization on the level of the...
Measurements of azimuthal correlations in the production of forward dijets in deep inelastic scattering provide the opportunity to probe the Weizsäcker-Williams gluon transverse momentum dependent (TMD) parton distribution, and the possibility for the discovery of gluon saturation at the future Electron-Ion Collider (EIC). While the TMD factorization is expected to hold near back-to-back...
The Belle II experiment at the SuperKEKB energy-asymmetric e+e− collider is an upgrade of the B factory facility at KEK in Tsukuba, Japan. The experiment began operation in 2019 and aims to record a factor of 50 times more data than its predecessor. Belle II is uniquely capable of studying the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks. First...
In the recent years, several measurements of B-decays with flavor changing neutral currents, i.e. $b \to s$ transitions hint at deviations from the Standard Model (SM) predictions. In addition there are discrepancies with the SM predictions in $ b \to c \tau \nu$ decays. The Belle II experiment is a substantial upgrade of the Belle detector and operates at the SuperKEKB energy-asymmetric...
In recent years, the radial excitations of heavy hadrons have been identified in experiments. Motivated by that, we have studied their decay properties in the nonrelativistic constituent quark model. It is found that the relativistic correction is essential to explain the large decay width indicating that the relativistic model may be necessary. In this talk, we will discuss our attempt to...
The light front wave functions (LFWFs) are conventionally obtained by solving the light-cone QCD Hamiltonian. In this talk, I'll demonstrate an alternative approach, which is to extract the leading Fock-state LFWFs (LF-LFWFs) of light and heavy pseudo-scalar and vector mesons from their dynamically solved Bethe-Salpeter wave functions. An important property of these LF-LFWFs is that they imply...
We discuss an application of the cluster effective field theory (EFT) to nuclear reactions at low energies. A target reaction of the present talk is the $E1$ transition of radiative $\alpha$ capture on $^{12}$C, which is a fundamental reaction in nuclear-astrophysics. We review our recent works to construct the cluster EFT for the reaction, fix some of the coupling constants of the effective...
We present the generalized parton distributions (GPDs) of the pion and the kaon in both momentum and position spaces within the basis light-front quantization framework. We obtain these GPDs for the valence quarks from the eigenvectors of a light-front effective Hamiltonian in the valence Fock sector consisting of the holographic quantum chromodynamics (QCD) confinement potential, a...
Following our previous work (W. Qian, S. Jia, Y. Li and J.P. Vary, Phys. Rev. C 102, 055207 (2020); arXiv:2005.13806) on light unflavored mesons as a relativistic bound-state problem within the nonperturbative Hamiltonian formalism, we present the numerical calculations on simulated quantum devices using the basis light-front quantization (BLFQ) approach. We implement and compare the...
We present the first results of all-charm tetraquark calculations using many-body basis function approach in the Front Form of Hamiltonian dynamics known as Basis Light-Front Quantization (BLFQ). We numerically find masses of the ground-state tetraquark and three estimates of the lowest two-meson threshold. All degrees of freedom of each quark and antiquark are explicitly taken into account....
In this talk we study the valence quark and gluon distributions of the pion and kaon in the Nambu-Jona-Lasinio (NJL) model with the help of the proper-time regularization (PTR) scheme that simulates confinement. We then explore the gluon contents of the pion and kaon, that recently attract more attention of hadronic physicist. A comparison with other model and lattice predictions as well as...
The structure of charmonia is usually described by two important physics: Coulomb-like potential arising from one-gluon exchange and quark-confining one to keep the quarks inside charmonia. However, the strength of the strong coupling constant often employed in this potential approach is known to be overestimated. While the effects from the instanton, which is one of the most well-known...
We present recent results of transverse single-spin asymmetries (TSSAs) for inclusive neutral pions using the Forward Meson Spectrometer at STAR in proton-proton collisions at center of mass energies of 200 and 500 GeV. The results from the two energies show that the pion TSSA increases continuously with Feynman-$x$. Comparisons with previous measurements show that the pion TSSA is mostly...
Basis Light-front Quantization is a method starting from the first-principle Lagrangian to simultaneously get the mass spectrum and internal information of many bound states within a feasible computation time. Among the internal information of bound states, transverse-momentum-dependent PDFs (TMDs) have received increasing attention recently because they provide a full momentum space 3D...
We inverstigate the electron-positron pair production in electric fields with spatio-temporal inhomogeneity using a Hamiltonian method based on light-front quantization. We truncate the Fock space up to the sector containing $4$ pairs of electrons and positrons, by which we can track each particle fully quantum-mechanically. We calculate observables such as the invariant mass and the...
A chiral quark-soliton model (CQSM) is a relativistic pion mean-field approach in the large $N_{c}$ limit, which describes baryon as a bound state of the $N_{c}$ valence quarks by the pion mean field. In the infinitely heavy mass limit of the heavy quark, a singly heavy baryon can be viewed as an $N_{c}-1$ chiral soliton with the heavy quark as a static color source. In this framework, we...
We study the gravitational form factors (GFFs) and the mechanical properties like the pressure and shear distributions inside a relativistic spin-$\frac{1}{2}$ composite object like a quark dressed with a gluon, using light-front wave functions. Using the symmetric energy-momentum tensor for QCD, we calculate the analytical expression for the four GFFs $A(q^2)$, $B(q^2)$, $C(q^2)$ and...
Since 2010, the Compact Muon Solenoid (CMS) Experiment at the CERN Large Hadron Collider (LHC) has collected an unprecedented amount of proton-proton collision data in the center of mass energies of 7, 8 and 13 TeV. These data are used to conduct hundreds of analyses that test the validity of the standard model and look for hints of beyond the standard model physics. The biggest highlight so...
An overview of the ATLAS physics program is presented, with emphasis on the most recent results obtained fully exploiting the abundant and now well-understood dataset recorded during Run 2 of CERN’s Large Hadron Collider (2015-2018). The talk will also describe the ongoing improvements of the ATLAS detector targeting Run 3 and the subsequent LHC high luminosity phase.
Nucleon-to-meson and nucleon-to-photon transition distribution amplitudes (TDAs) arise in the collinear factorized description of a class of hard exclusive reactions characterized by the exchange of a non-zero baryon number in the cross channel. In this talk, we review the properties of nucleon-to-photon (and photon-to-nucleon) TDAs, which encode the photon content of the nucleon and allow a...
Hard exclusive processes are a well established tool to study the 3D nucleon structure. The QCD factorisation mechanism in the "nearly forward region" ($t/Q^2$ small) can be divided into a hard part, described by perturbative QCD (pQCD) and in two general structure functions, the Generalized Parton Distributions (GPDs) for the nucleon and the pion Distribution Amplitudes (DAs), describing the...
I will discuss how a trivial light cone vacuum can be compatible with a nontrivial vacuum in an equal time framework. In particular I will discuss the role of zero modes and their role in the light-front formulation.
I discuss a relativistic light-front model of hadrons based on strong-coupling QCD degrees of freedom that is designed to be simple enough to explore the role of sea quarks in hadronic structure and reaction calculations. The degrees of freedom are confined local and global color singlet systems quarks of antiquarks connected by ``strings'' represented by confining interactions. These bare...
As has been seen in recent calculations for $\phi^4$ theory, tadpole contributions are important for symmetry-breaking effects and yet are missing from standard light-front calculations, because they require transitions to and from the vacuum. Inclusion of such vacuum transitions also implies contributions from vacuum bubbles. A perturbative calculation can make the distinction and subtract...
We trace the development of light-front quantization from its infinite momentum frame origin to its current formulation. We emphasize its difference from the infinite momentum frame approach especially in regard to vacuum loop diagrams. We identify the importance of off mass shell light-front contributions, especially in regard to circle at infinity contributions to vacuum Feynman diagram...
The Generalized Polarizabilities (GPs) are fundamental properties of the nucleon. They characterize the nucleon's response to an applied electromagnetic field, giving access to the polarization densities inside the nucleon. As such the GPs represent a central path towards a complete understanding of the nucleon dynamics. Previous measurements of the proton electric GP at intermediate...
The Belle experiment using KEKB collider at KEK, Japan, has made immense contribution to heavy flavor physics with observations of CP violation in B systems and rare B-meson decay measurements. The Belle II experiemnt using SuperKEKB is an upgrade of Belle and aims at collecting 50 times more data. In this talk, we present a selection of recent physics results from Belle. In particular, we...
Hadrons are complex systems of quarks (and gluons) first formed and followed by matter evolution in the universe. The strong interaction plays an important role in formation of matter. The quantum chromodynamics (QCD), which is the fundamental theory of the strong interaction, shows highly non-perturbative behaviors in low energy and thus is difficult to solve. A fundamental question, how...
We improve our previous variational method based nonrelativistic quark model by introducing a complete set of three-dimensional harmonic oscillator bases as the spatial part of the total wave function. After fitting to the masses of the ground state hadrons, we apply our new method to analyzing the doubly heavy tetraquark states $qq'\bar{Q}\bar{Q'}$. In particular, we compare the result for...
We discuss multi-charmed and exotic hadrons in heavy ion collisions by focusing on their production based on both the statistical and coalescence models. Starting from the investigation on estimated yields of multi-charmed hadrons in the statistical hadronization model, we consider transverse momentum distributions of those hadrons produced at quark-hadron phase transition in the coalescence...
We perform a sensitivity study of an un-binned angular analysis of the $B\to D^*\ell \nu_\ell$ decay, including the contributions from the right-handed current. We show that the angular observable can constrain very strongly the right-handed current without the intervention of the yet unsolved $V_{cb}$ puzzle.
Experimental results from hadron-hadron scatterings or decays are usually interpreted by using some phenomenological models. The conventional model-fitting scheme cannot give us a definitive answer because different models can give almost similar goodness of fit. In our work, we show that deep learning can be used as a unified model-selection tool. We prepared 35 pole-based models and train...
In this talk, I would consider the light-front quantization of the Maxwell Chern-Simons Higgs theory using the Hamiltonian and path integral formulations.
We investigate the two-photon transitions $c\bar c \to \gamma^*\gamma$ of the charmonium system in light-front dynamics. The light-front wave functions were obtained from solving the effective Hamiltonian based on light-front holography and one-gluon exchange interaction within the basis light-front quantization approach. We compute the two-photon transition form factors as well as the...
We present our recent studies on the quasi-parton distribution functions in the nucleon within the chiral quark-soliton model. We discuss the properties of the isoscalar unpolarized and isovector polarized quasi-PDFs in the large $N_c$ limit, such as the generalized sum-rules and the nucleon momentum evolutions. From the model calculations, we observe that the isoscalar unpolarized quasi quark...
We will discuss the effects of bulk viscous quark gluon plasma medium on the quarkonium spectral functions. The bulk viscous correction is incorporated in the distribution functions of thermal quarks and gluons, with which we compute the dielectric permittivity. The modified dielectric permittivity is used to calculate the in-medium heavy quark potential. Using the modified heavy quark complex...
We discuss in detail the basic ideas behind the medium modifications of the chiral soliton models. We also demonstrate their applications to study an in-medium baryon properties in different (heavy, light) sectors, nuclear matter properties in different (low, ordinary, high, extreme) density regions, the finite nuclei properties and related phenomena.
We investigate $P$-wave bottom baryons of the $SU(3)$ flavor $\mathbf{6}_F$, and systematically study their $D$-wave decays into ground-state bottom baryons and pseudoscalar mesons. a rather complete study is performed on both mass spectra and decay properties of $P$-wave bottom baryons, using the method of QCD sum rules and light-cone sum rules within the framework of heavy quark effective...
We calculate the masses of the vector and axial-vector mesons, as well as the nucleon and the delta resonance in the chiral symmetry, restored vacuum. This is accomplished by separating the quark operators appearing in the QCD sum rules for these hadrons into the chiral symmetric and symmetry breaking parts depending on the contributions of the fermion zero modes. We then extract the vacuum...
We obtain the distribution amplitude (DA) of the pion from its light-front wave functions in the basis light-front quantization framework. This light-front wave function of the pion is given by the lowest eigenvector of a light-front effective Hamiltonian consisting a three-dimensional confinement potential and the color singlet Nambu--Jona-Lasinion interaction both between the constituent...
In the present talk, we will show how the axial-vector meson $a_1(1260)$ emerges as a quasi-bound state consisting of the kaon and anti vector kaon or a hadronic molecular state. We first construct a dynamical model for $\pi\rho$ scattering based on the fully off-mass-shell coupled-channel formalism. The model includes both the $\pi\rho$ and $K\bar{K}^*$ channel. The axial-vector meson...
We obtain the masses, the electromagnetic properties, and the parton distribution functions (PDFs) of the baryons (with a strange quark $\Lambda$ and a charm quark $\Lambda_c$, and their isospin triplet baryons) from a light-front effective Hamiltonian in the leading Fock sector. The effective Hamiltonian consists of the confining potential adopted from light-front holography in the transverse...
We investigate the single transverse spin asymmetry of the very forward neutral pion production from interferences between $p$, $\Delta(1232)$, $N^*(1535)$ and $\Delta (1700)$ Reggeons. The Born amplitudes for the $p + p^\uparrow \to \pi^0 + X$ are factorized to the proton-pion-baryon vertex and inclusive proton-baryon amplitude $A_{pB \to X}$. The optical theorem leads these amplitudes to be...
In this talk I present a new method to compute the light-front wave functions for a system of two interacting scalar particles using contour deformations. After solving the two-body Bethe-Salpeter equation, the projection onto the light front is done through a combination of contour deformations and analytic continuation methods. The resulting light-front wave functions and distribution...
In this talk, we present our recent work for a canonical approach for extreme QCD. We discuss the canonical approach for the study of QCD phase at finite densities and temperatures in the confinement phase. The canonical approach, which is a method to extrapolate observables calculated at pure imaginary chemical potentials to those at real chemical potentials, is useful to overcome the sign...
A key step to improve our understanding of nucleon structure in terms of Generalized Parton Distributions (GPDs) is the measurement of Deeply Virtual Compton Scattering on the neutron (nDVCS; $ed \to e'nγ(p)$). This process provides mainly, in the kinematic range covered at Jefferson Lab, an access to the GPD $E$ of the neutron, which is the least known and constrained GPD as of today. The...
A leap in our understanding of hadronic structure formation was witnessed during the last decade. The discovery of the $X, Y, Z$ states in the (hidden) charm meson sector first by Belle, and the $P_C$ baryon states by LHCb revealed the existence of multi-quark objects beyond the simple quark-antiquark or 3-quark valence configurations. While the detailed structure of such states is still under...
The parton structure is studied using mainly two types of hard scattering processes: exclusive processes, which give access to Generalized Parton Distributions (GPDs), and semi-inclusive processes, described in terms of Transverse Momentum Dependent parton distributions (TMDs). In full QCD, no relations exist between GPDs and TMDs. However, a connection between T-odd effects related to TMDs...
Recently, we have performed a Monte Carlo global QCD analysis of pion parton distribution functions using Drell-Yan and leading neutron data. Since then, we have systematically implemented threshold resummation on the Drell-Yan cross section using various methods of the calculation, each of which differently impacts the large $x$ distribution of the valence quark. Additionally, we have...
We study the light meson with one dynamical gluon on the light-front quantum chromodynamics (QCD) Hamiltonian as well as a three-dimensional confinement. After fitting the light meson mass spectroscopy, the light-front wave function provides a good description of the pion electromagnetic form factor, decay constant, and the valence quark distribution functions following QCD scale evolution.
In this talk I will present a dynamical model for the pion based on the solution of the Bethe-Salpeter equation in Minkowski space. For this end, we use the Nakanishi integral representation of the Bethe-Salpeter amplitude. The input of the interaction kernel has the quark and gluon masses, and also a scale parameter related to the extended quark-gluon vertex. Within this model, we obtain the...
An effective potential between two fixed sources is computed in light-front quantization for a quenched scalar Yukawa theory. The quenching removes pair-production processes that would result in a spectrum unbounded from below. The sources are fixed with respect to ordinary time, but move in the light-front longitudinal direction. The neutral scalar field is represented by a coherent state,...
We made simultaneous extraction of spin averaged and spin dependent PDFs within multistep MC procedures, with combined analysis of inclusive unpolarized and polarized jets from RHIC to Tevatron energies. By analyzing the preliminary results we had, we were able to discuss impact of theory assumptions on $\Delta g$.
In this talk, I will argue that the light-front holographic Schrodinger Equation and the `t Hooft Equation are complementary to each other in governing the transverse and longitudinal dynamics of colour confinement in hadrons. Together, they predict remarkably well the light, heavy-light and heavy-heavy hadrons spectroscopic data, with a universal confinement scale in the holographic...
The rare Z hadronic decays and heavy flavored decayes provides new perspectives to probe the quark sector. Here we propose to study various topics for future colliders working at the $Z$ pole. The study will also further motive detector R$\&$D for the FCC-ee, CEPC and other proposed experiments.
In recent years, many efforts have been developed to formulate and solve the Bethe-Salpeter and Dyson-Schwinger equations (DSE) directly in Minkowski space, in contrast to the usual procedure of formulation in the Euclidean space and subsequent extension to Minkowski space, which is the approach used in lattice gauge theories. In this work, the fermion self-energy is calculated from the...
In the present work, the electroweak properties of light and charmed $D$ and $D_s$ pseudoscalar mesons are explored with the covariant constituent quark model. The quark-antiquark-meson vertices are assumed to have a symmetric form by the exchange of quark momenta, which is successful in describing the light pseudoscalar meson properties. The flavor decomposition of the elastic...
In this work we present results on the nucleon axial form factor and on correlations between the static electroweak observables by using a scalar spin coupling between quarks fields and nucleon fields in a constituent light front quark model. In the context of the Bakamjian-Thomas (BT) of the quark spin coupling scheme it was shown that the axial coupling constant, the proton magnetic moment...
The nucleon electromagnetic properties are studied in a constituent light front quark model by using a scalar spin coupling between quarks fields and nucleon fields. We have studied a comparison between one scale wave function and two scale wave function. The introduction of a high momentum scale in the wave function moves the value of the square momentum transfer, in which the zero of...
The talk will include our study on the single hadron inclusive production in the forward rapidity region in proton-nucleus collisions. We find the long-standing negative cross section at next-to-leading-order (NLO) is driven by the large negative threshold logarithmic contributions. We established a factorization theorem for resumming these logarithms with systematically improvable accuracy...
We present the construction of a simple-functional form light-front wavefunctions (LFWFs) of charmonium states on a small-sized basis function representation. In this work, we modeled the LFWFs for four charmonium states, $\eta_c$, $J/\psi$, $\psi'$, and $\psi(3770)$ as superpositions of orthonormal basis functions.The basis functions are eigenfunctions of an effective Hamiltonian, which has a...
The light-front quantization provides a natural framework for digital quantum simulation of quantum field theory. In our previous work (2002.04016, 2105.10941), we demonstrated this by developing quantum algorithms based on simulating time evolution and adiabatic state preparation. Aiming for near-term devices, in my talk I will explain how to formulate the relativistic bound state problem as...
When the electromagnetic field is applied to a charged particle, the particle motion is described by the Lorentz force equation which reveals the connection between the electromagnetic field strength tensor and the Lorentz transformation generators represented by the boost and the rotation. We interpolate the Lorentz force equation between the instant form dynamics and the light-front dynamics...
It is well known that light-front field theories suffer from the appearance of higher-order poles when treated in Feynman's approach to perturbative quantum field theory, originated in the non-local terms which arise in Feynman's propagators of some fields in light-front dynamics. The regularization of these terms is a delicate issue, as there are many prescriptions to do it. In null-plane...
The instant form and the front form of relativistic dynamics introduced by Dirac in 1949 can be interpolated by introducing an interpolation angle parameter $\delta$ spanning between the instant form dynamics (IFD) at $\delta=0$ and the front form dynamics, which is now known as the light-front dynamics (LFD) at $\delta=\frac{\pi}{4}$. We extend the Poincar\'e algebra interpolation between...
The pion plays a special role in the understanding of QCD, the main one is its Goldstone boson nature, associated with the origin of the mass from the dynamical chiral symmetry breaking. One of the possible ways to get information about its substructure, in terms of the degrees of freedom of QCD, quarks and gluons, is from the study of the elastic electron-pion scattering. Because the pion...
Light-front dynamics (LFD) has been of particular interests in hadron physics with the effort of developing the 3D femtography of the nucleon. In this respect, it is important to trace the instantaneous contribution to the fermion propagator in the LFD which involves the constraint degrees of freedom of the fermion. Interpolating the ordinary instant form dynamics (IFD) to the LFD in quantum...
We investigate the ``scalar pion'' $\to \gamma^*\gamma^*$ transition form factor for the two emitted virtual photons of momentum squares $q^2$ and $q'^2$ in both space-like and time-like regions. In 1+1 dimensional scalar field model, we use the direct method in the light-front dynamics (LFD) to access the time-like region without resorting to analytic continuation. In particular, we define...
In the present talk, we provide the results for the axial-vector transition form factors $C_{5}^{A}(Q^{2})$ from the baryon decuplet to the baryon octet, based on a pion mean-field approach, taking into account the rotational $1/N_{c}$ corrections and the effects of flavor SU(3) symmetry breaking. We obtain all possible axial-vector transition form factors for both the strange-conserving and...
The proton decay is forbidden in the standard model of particle physics. Hence, any signature of proton decay will be a clear signal of new physics beyond the standard model. In this talk, we discuss the $p\rightarrow e^+ \gamma$ decay. It is mediated by the baryon number violating operators of dimension 6 and includes two form factors. We discuss these form factors in the framework of light...
In this talk, we consider a light-front supersymmetric field theory described by the Wess-Zumino model (WZM) which remains invariant under rigid/global supersymmetry transformations (that rotate bosons into fermions and fermions into bosons). The theory satisfies the super Poincare algebra (SPA) and has a non-manifest supersymmetry (different from the superfield formalism). The instant-form...
We investigate the leading-twist transverse-momentum-dependent distribution functions (TMDs) for the $\Lambda^0$ and the $\Lambda_c$ heavy baryon, a spin-1/2 composite system consisting of two light quarks ($u$ and $d$) and a heavy quark s/c, using the basis light-front quantization (BLFQ) framework. The light-front wave functions of the heavy baryon in the leading Fock sector are obtained...
Within the context of the in-medium modified chiral soliton model, we present a recent results for the characteristics of baryonic matter. The model's intrinsic parameters are derived by reproducing nuclear matter properties near the saturation density and fitted by using nuclear phenomenology at the nonstrange sector. We obtain an equation of state that is consistent with numerous...
In this talk, I would like to present some trivial and non-trivial relations between transverse momentum-dependent parton distributions (TMDs) and generalized parton distributions (GPDs) in a light-front quark-diquark model motivated by soft-wall AdS/QCD. And I will show that the relation between the Sivers function and GPD $E^{q}$ can be obtained in terms of the Lensing function and I will...
We discuss how the masses of the singly heavy baryons undergo changes in nuclear matter within the framework of a medium-modified SU(3) chiral soliton model. In order to incorporate a heavy quark inside a singly heavy baryon, we introduce the heavy mesons with heavy-quark spin-flavor symmetry considered. We first reproduce bulk properties of nuclear matter such as the saturation energy and...
We obtain the light-front wavefunctions (LFWFs) of the nucleon from the light-front quantum chromodynamics (QCD) Hamiltonian, determined for its constituent three-quarks and three-quarks-gluon Fock components, together with a three-dimensional confinement. The eigenvectors of the light-front effective Hamiltonian provide a good quality description of the nucleon electromagnetic and axial form...
Understanding the structure and dynamics of the proton constitute one of the most important challenges in hadron physics. From the theoretical point of view, one of the challenges is to extract from Lattice QCD calculations, performed in Euclidean space, Minkowskian quantities such as the proton parton distribution function. Due to the inherent difficulties associated with the mapping of...
We analyse the rare semileptonic decays of $B$ meson to axial vector mesons $K_1(1270)$ and $K_1(1400)$ mediated by the flavor changing neutral current $b \to s ll$ quark level transition, in an effective field theory approach. We perform a global fit to all the relevant and up-to-date $b \to sl^+ l^-$ data for various sets of (axial)vector couplings. We then look over the implications of the...
How the bulk of the Universe's visible mass emerges and how it is manifest in the existence and structure of hadrons are fundamental questions yet to be answered. Understanding the underlying mechanisms requires being able to explain the structural properties of the pion and kaon. In this talk, we shall discuss many aspects on the internal structure of pion and kaon, as reveales by their...
Following simple large Nc arguments and perturbative QCD constraints complemented with uncertainty estimates based on the idea of meson dominance and the half-width rule, we describe the pseudoscalar form factors of the nucleon. We analyze their implications in the space-like region at intermediate and low energies and compare to recent lattice QCD determinations. Our analysis allows for a...
We analyse the use of wavelet transform in quantum field theory models written in light-cone coordinates. In a recent paper [W.N Polyzou, Phys. Rev. D 101(2020) 096004] the author used $x^+$ variable as 'time', and applied wavelet transform to the 'spatial' coordinates only. This makes the theory asymmetric with respect to space and time coordinates. In present contribution we generalize the...
We present exploratory studies of the 3D gluon content of the proton, as a result of analyses on leading-twist transverse-momentum-dependent (TMD) gluon distribution functions, calculated in a spectator model for the parent proton. Our formalism embodies a fit-based parameterization for the spectator-mass density, suited to describe both the small- and the moderate-x regime. Particular...
Nonfactorizable corrections induced by charm-quark loops in exclusive FCNC $B$-decays (i.e. $B$-decays induced by flavour-changing neutral currents) are discussed. We show that a consistent calculation of the appropriate QCD correlation function requires the full generic three-particle distribution amplitude (3DA) $\langle 0|\bar q(y)G_{\mu\nu}(x)b(0)|B(p)\rangle$ with non-aligned arguments:...
The semi-inclusive correlator for a $J =1/2$ bound-system, composed by A spin-$1/2$ fermions, is linearly expressed in terms of the light-front Poincare' covariant spin-dependent spectral function, in valence approximation. The light-front spin-dependent spectral function is fully determined by six scalar functions that allow for a complete description of the six T-even transverse-momentum...
The $J/\psi$ decays into octet baryon-antibaryons pairs is studied using the QCD factorisation framework. The power suppressed corrections are calculated for the first time using higher twist baryon light-cone distribution amplitudes. The obtained results are used for a phenomenological analysis of experimental data. It is found that the polarisation parameter $\alpha_B$ can be described ...
We develop a numerical method to nonperturbatively study scattering and gluon emission of a quark from a colored target using a light-front Hamiltonian approach. The target is described as a classical color field, as in the color glass condensate effective theory. The Fock space of the scattering system is restricted to the $|q \rangle +|qg \rangle$ sectors, but the time evolution of this...
Systems as $\mathrm{K^- p}$ and baryon--antibaryon ($\mathrm{B\overline{B}}$) are both characterised by the presence, already at the production threshold, of strong inelastic channels which can affect the properties and the formation of bound states and resonances. In the $\mathrm{\overline{K}N}$ system, the $\Lambda(1405)$ arises from the interplay between the $\mathrm{\overline{K}N}$ and the...
A brief overview of the experimental evidence for the non-zero intrinsic charm (IC) contribution to the proton PDF is presented. The effect of intrinsic heavy quarks on the production of vector bosons accompanied by $c$ and $b$ jets in $pp$ collisions at the LHC is then investigated. The calculations are performed within the combined QCD approach, based on $k_T$-factorization at small...
Recent results from the proton-proton collision data taken by the ATLAS experiment on charmonium production and on B_c production and decays will be presented. The measurement of the associated production of the $J/\psi$ meson and a gauge boson, including the separation of single and double parton scattering components, will be discussed. The measurement of $J/\psi$ and $\psi(2S)$ differential...
We studied the process $e^+e^- → KK\pi$ with the СMD-3 detector at the electron-positron collider VEPP-2000. The statistics collected by the СMD-3 detector in the energy range of $1.2-2$ GeV during the 2011, 2012, 2017, 2019 runs, with a total luminosity integral of $\sim120pb^{-1}$, was used for the analysis. The measured cross-section is crucial for the physics of light hadrons from $u, d,...
In this talk, we present recent results of the leading-twist distribution amplitudes for the nucleon and $\Delta$ baryon within the framework of the chiral quark-soliton model. We first construct the light-cone wave functions to the five-quark state. By employing them, we then obtain the distribution amplitudes in the leading-twist accuracy. We find that it is essential to consider the...
In this talk we discuss the nonfactorizable charm-loop effect in the rare FCNC decay $B_s \to \gamma \gamma$. The nonfactorizable contribution comes from the soft gluon emission from c-quark loop. The rigorous calculation requires the knowledge of three particle DA with three independent coordinates. We properly study the influence of three particle DA form on the amplitude by the case of $B_s...
I will discuss the extension of the nucleon spin sum rule to QCD$\times$QED. I will present the QED corrections to the evolution of the quark and gluon helicity and orbital-angular-momentum (OAM) distributions, which are calculated for the first time, and the necessary inclusion of photon and lepton helicity and OAM distributions.
We derive a new classical action for gluodynamics by canonically transforming the light cone Yang-Mills action, where the solutions to the field transformations are directly related to the straight infinite Wilson line functionals defined on the constant light-cone time $x^+$. One of the key features of the new action is that it has no triple gluon vertices, because they have been effectively...
The proton, and its isospin partner the neutron, are the building blocks of the visible universe and are responsible for almost the entirety of its mass. While the total mass of the proton is precisely known, the decomposition of this mass into its quark and gluon components touches upon some of the deepest mysteries in QCD. This talk will review this topic, discuss some of the recent theory...
Three current models of QCD in (1+1) dimensions are examined and extended in light-front coordinates. A pion of high momentum is found to have an infinite extent along its direction of motion.
I formulate the basic concepts underlying the development of parton pseudodistributions functions and review its recent applications to the lattice QCD extractions of parton distributions.
Feyman's parton model played an important role for the understanding of the Bjorken scaling in the first DIS experiments and paved the way towards QCD. Various versions of parton model frameworks have been used in literature to study nucleon structure, target mass corrections and other partonic properties. The properties of the quark correlator are determined by the equations of motion of the...
Studies of the nucleon resonance spectrum and structure offer the unique information on strong interaction dynamics which underlies the generation of excited nucleon states with different structural features. The advances in exploration of the $N^*$ spectrum which result in discovery of several long time awaited new baryon states (previous "missing resonances") will be presented. The prospects...
We construct a Reggeized model for the $u$-channel baryon exchange to investigate parton contribution to various types of hadron reactions at backward angles. Backward photoproductions of lighter vector mesons $\rho^0(770)$, $\omega(785)$, and $\phi(1020)$ off the proton target are investigated with a common set of parameters for the parton distribution function. Analysis of pion...
Jets are produced in heavy-ion and nucleon-nucleon collisions from hard-scattered patrons of the incoming beams. We can infer the property of hot-dense QCD matter, known as Quark-Gluon Plasma (QGP), by studying the modified jet properties in heavy-ion collisions to their vacuum reference. Relativistic Heavy-Ion Collider (RHIC), at BNL, New York, USA, can collide heavy-ions (like Au+Au and...
NA66/AMBER (Apparatus for Meson and Baryon Experimental Research) has been approved at the CERN Super Proton Synchrotron for a broad research program in quantum chromodynamics. The program ranges in a first phase to about the year 2026, from a precision measurement of the proton radius using a 100-GeV muon beam, to investigations of the quark-gluon structure of mesons in Drell-Yan processes....
In January 2020, the US DOE approved the realization of the Electron Ion Collider (EIC) to be built at Brookhaven National Laboratory (BNL) in partnership with Jefferson Laboratory. An "EIC project" was stood up and it is now leading the realization of the machine and working with the world-wide EIC Users towards the construction of up to two EIC detectors. In this talk, I will review the...
The electron ion collider (EIC) is the future particle accelerator to be built at the Brookhaven National Laboratory (BNL). It will collide electrons and various nuclei to precisely measure the internal structure of nuclei, including the spin and momentum distribution of quarks and gluons. It is also expected to provide unprecedented hard probe data to shed light on the strong interaction in...
Newly operational, anticipated, and planned factilities have the potential to change the hadron physics landscape. Each one of the participants has expressed their perspective on how our community can advance over this new ground. This presentation will attempt to capture some of the excitement surrounding the journeys that are underway or may soon begin.
I will first review several topics in hadron mass and chiral symmetry restoration. Then I will discuss the current status of hadron mass shift measurements in nuclear medium. Finally, I will discuss some recent suggestions on $K_1$ and $K^*$ meson mass measurements both in heavy ion collision and nuclear target experiments.
