Conveners
Parallel Session D: Structure of hadrons 1
- Yasuhiro Yamaguchi (Nagoya University)
Parallel Session D: New facilities & instrumentation 1
- Kiyoshi Tanida
Parallel Session D: Recent developments in QCD 2
- Takumi Doi
Parallel Session D: Recent developments in QCD 3
- Craig Roberts (Nanjing University)
Parallel Session D: Structure of hadrons 2
- James Zanotti (The University of Adelaide)
Parallel Session D: Structure of hadrons 3
- Sachiko Takeuchi
We investigate the $\phi N$ reaction using an effective Lagrangian model combined with Reggeized $\rho$ and $b_1$ exchanges in the $t$-channel. The strong $\phi N N^*$ coupling leads us to include the nucleon, several $N^*$ resonances, and a hidden-strangeness state $P_s$ in the $s$- and $u$-channels. The Regge approach follows the same procedure as in the $K^+ p \rightarrow K^{*0} n$...
Energy momentum tensor (EMT) expresses the interaction between the gravitation and the matter fields, in which the scattering off the graviton is a natural but infeasible probe. However, the EMT can be accessed indirectly through electromagnetic interactions in quantum chromodynamics. The matrix elements of the local EMT operator are parametrized by gravitational form factors, which are...
Recently, the gravitational form factors (GFFs) of the nucleon have been extensively studied both theoretically and experimentally, with the aim of deepening our understanding of its internal structure. However, many details remain unclear, especially the connection between the GFFs and the non-perturbative aspects of QCD.
In our study, we focus on the role of the scale anomaly in nucleon...
The lattice QCD computation of parton distributions within the framework of large momentum effective theory (LaMET) constitutes a first-principles approach to studying hadron structures. Building upon preceding studies on meson systems, we have developed and partly implemented lattice methodologies for calculating the leading twist LCDAs of light baryons under the LaMET formalism over the past...
We present the results of lattice QCD calculation of all leading-twist x-dependent Light-cone Distribution Amplitudes (LCDAs) for baryons in light octet, within the framework of Large-momentum Effective Theory (LaMET). We implement a novel Hybrid renormalization scheme for baryon nonlocal operators, and perform simulations at 4 different lattice spacings a = {0.052, 0.068, 0.077, 0.105} fm,...
The tensor form factors of the nucleon provide essential information
for understanding its internal spin structure. The monopole tensor
form factor at $Q^2=0$ is identified as the nucleon tensor charge,
which corresponds to the first moment of the leading-twist transverse
parton distribution function $h_1(x)$. While transversity has been
extensively studied both theoretically and...
The Center for Exotic Nuclear Studies (CENS) has developed a diverse set of experimental instruments to enable precision measurements with rare isotope beams. These systems address key challenges in nuclear astrophysics and structure studies, including low-intensity beam conditions, inverse kinematics, and complex reaction channels. Recent developments include beam purification systems,...
The Reactor Experiment for Neutrinos and Exotics (RENE) is designed to investigate sterile neutrinos in the region of ฮmยฒ ~ 2 eVยฒ.
The prototype detector consists of a cylindrical target filled with 0.5 tons of gadolinium-loaded liquid scintillator (Gd-LS), surrounded by a box-shaped gamma catcher containing 1.5 tons of liquid scintillator (LS), and equipped with two 20-inch PMTs.
The...
The RENE (Reactor Experiment for Neutrinos and Exotics) experiment aims to search for sterile neutrinos in theฮmยฒ โ 2 eVยฒ region at a baseline of about 23 m from the reactor core. The prototype detector consists of a 0.5-ton cylindrical target filled with 0.5% gadolinium-loaded liquid scintillator (GdLS), surrounded by a 1.5-ton box-shaped gamma catcher with liquid scintillator (LS). The...
ALADDIN (An LHC Apparatus for Direct Dipole moments INvestigation, https://aladdin.web.cern.ch/) is a proposed compact fixed-target experiment at the LHC, designed to enable precise measurements of charm baryon electromagnetic dipole moments. The experiment leverages an innovative storage-ring layout that redirects protons from the beam halo onto a solid target, coupled with a bent crystal....
With the existing 10 billion J/ฯ events accumulated at BESIII, the high production of long-lived baryons in J/ฯ decays serves as a novel source of hyperon beams, which open a unique opportunity for exploring the hyperon-nucleon interactions. By studying the interactions of these hyperons with the beam pipe and the inner tube of the MDC detector, the recent results achieved at BESIII,...
The High-Acceptance Di-Electron Spectrometer (HADES) operates at the GSI Helmholtzzentrum fuฬr Schwerionenforschung in Darmstadt, using pion, proton, and heavy-ion beams provided by the SIS-18 synchrotron [1]. In February 2022, the HADES Collaboration measured proton-proton collisions at 4.5 GeV kinetic energy using the upgraded setup as part of the FAIR-Phase0 program [2]. One of the key...
The upcoming Electron Ion Collider promises unprecedented access to the internal structure of hadrons and nuclei encoded in parton distribution functions (PDFs). With the development of effective theory approaches, such as quasi- and pseduo-PDFs, first principles Lattice QCD simulations take aim at precision computation PDFs, offering complementary insight.
The extraction of physical PDFs...
We present results on baryon spectroscopy in thirteen 2+1-flavor lattice QCD using Wilsonโclover fermion ensembles generated by the JLab/ W\&M/LANL/MIT/Marseille collaborations. From the baryon spectra we determine, we track the chiral and lattice-spacing dependence, enabling a precise determination of the physical scale. Taken together, these results suggest a systematic strategy for...
We perform an evaluation of the polarised Bjorken sum rule (BSR) $\overline{\Gamma}^{p-n}_1(Q^2)$ with truncated Operator Product Expansion (OPE) up to the $D=4$ term [1]. Using the knowledge of the renormalon structure of the BSR, the leading-twist term of dimension $D=0$ is evaluated using a renormalon-based resummation [2], in this case [1] with two variants of previously developed...
We examine the transitional behavior of dynamical chiral symmetry breaking in the interacting instanton liquid model (IILM) with $N_f=2$ and $N_f=2+1$ flavors. In our previous study, we demonstrated that in the IILM with the dynamical quarks of $N_f=3$, chiral symmetry breaking is driven in an anomaly-assisted manner. In contrast, our quenched calculation of the IILM revealed a typical...
In this talk, we will discuss the multiplicity distribution in deep inelastic processes on a heavy nucleus in the framework of high-energy QCD. We will present a new derivation for the cross sections of productions of $n$ gluons in the final states ($\sigma_n$), obtained using the dipole picture of high-energy QCD and consistent with the equations derived from the Abramovsky-Gribov-Kancheli...
A symmetry-preserving analysis of strong interaction quantum field equations is used to complete a unified treatment of pion, kaon, and nucleon electromagnetic and gravitational form factors. Findings include a demonstration that the pion near-core pressure is roughly twice that in the proton, so both are significantly greater than that of a neutron
star; parton species separations of the...
The vector mesons photoproduction off proton at high energy is widely assumed to proceed via mechanism that are sensitive to glue physics in the target proton. On the basis of the factorisation theorem, this kind of process can be considered as three separate parts: the fluctuation of the virtual photon into a quark-antiquark pair; the interaction of the quark-antiquark pair with the proton;...
By exploiting crossing symmetry, a unified treatment of the pion, kaon, proton distribution functions (DFs) and fragmentation functions (FFs) was accomplished. It gives insights into the link between two important phenomena in QCD: EHM and confinement. After evolving to higher scale, it provides coherent picture of fragmentation across all parton types. The obtained FFs conform with the...
Recent measurements of the protonโs flavor asymmetry by the SeaQuest/E906 experiment challenge earlier results from NuSea/E866 at large momentum fraction $x$ , underscoring the need for a deeper understanding of the nonperturbative structure of the nucleon sea. A widely invoked theoretical framework is the pion cloud model -- yet it is typically treated perturbatively, despite the...
In this talk, I will review recent advances in the study of baryon structure using high-energy probes through hard exclusive reactions. Particular emphasis will be placed on the role of generalized parton distributions (GPDs) as a framework for accessing multidimensional information on the internal structure of baryons. I will discuss how three-dimensional imaging and momentum-space tomography...
The dominant contribution to the theoretical uncertainty in the extracted weak parameters of the Standard Model comes from the hadronic uncertainties in the electroweak box diagrams, i.e. $\gamma-W^\pm/Z$ exchange diagrams. A dispersive analysis relates the box diagrams to the parity-odd structure function, $F_3$, for which the experimental data either do not exist or belong to a separate...
Generalized parton distributions (GPDs) for hadron-to-resonance transition establish a framework for understanding the internal structure of hadronic excitation in QCD. Non-diagonal hard exclusive reactions, such as deeply virtual Compton scattering (DVCS) and meson production (DVMP) involving $N \to N^*$ transition, serve as useful channels for empirical access to the corresponding transition...
MFFs of nucleons have been widely studied by both experiment and theory. However, the research on hyperons are not so dedicated. In our present work, we analyzed EMFF of the hyperon. The potentials are calculated from SU(3) chiral effective field theory and the scattering amplitudes are solved by Lippmann-Schwinger equation, the amplitudes of electron-positron annihilating into...
We investigate electromagnetic properties of nucleons within the framework of an effective chiral theory derived from the QCD instanton vacuum. It was based on the nonlocal $2N_f$ quark interactions, which can be bosonized to be the nonlocal effective chiral action with the momentum-dependent dynamical quark mass. A great merit of this approach is that it does not have any adjustable free...
We present the tomographical structure of spin-1/2 baryons by studying the nonforward matrix elements of lightlike correlation functions of the tensor current. At the leading twist, with the tensor current, four chiral-odd distributions are in count. We calculate these distributions in a diquark spectator model with light-front formalism by considering purely transverse momentum transfer,...
We compare LHCb measurements of J/ฯ and ฯ(2S) transverse momentum distributions within jets with QCD calculations, which may be crucial in understanding the quarkonium production mechanism. Our theoretical calculations are based on the fragmenting jet function formalism, while the nonperturbative formation of quarkonia is described by the nonrelativistic QCD factorization formalism. We include...
In this study, we investigate the influence of the QCD scale anomaly on the internal pressure distributions of the pion and nucleon, based on the trace-traceless decomposition of the energy-momentum tensor. We use recently reported model-independent results for the gravitational form factors, together with our own calculations within a top-down holographic QCD approach, to evaluate the...
The string-based formalism to Generalized Parton Distributions (GPDs) introduced in Phys.Rev.Lett. 133 (2024) 24, 241901 offers a unique opportunity to study the three-dimensional structure of the nucleon without any fine-tuning of parameters. Leveraging next-to-leading order PDF fits to parametrize the moments used in the conformal moment expansion of GPDs, the approach satisfies by...
There has been considerable progress in the study of the electromagnetic form factors of baryons in the timelike region, through electron-positron scattering ($e^+ e^- \to B \bar B$ reactions), in the last two decades. Timelike experiments reveal information about the distribution of charge and magnetism inside the hyperons that cannot be obtained in spacelike experiments (electron scattering...
We study radiative corrections to low-energy charged-current processes involving nucleons, such as neutron beta decay and (anti)neutrino-nucleon scattering within a top-down effective-field-theory approach. First, we match the Standard Model to the low-energy effective theory valid below the weak scale, specifying the scheme dependence of the Wilson coefficients. We evolve the resulting...
