Conveners
Nucleon helicity structure: 01
- Stephen Pate (New Mexico State University)
- Emanuele Roberto Nocera (Università degli Studi di Torino and INFN Torino)
Nucleon helicity structure: 03
- Craig Roberts (Nanjing University)
Description
Conveners: Matthew Posik, Raza Sabbir Sufian, Jinlong Zhang
Using continuum Schwinger function methods, a coherent set of predictions for proton, Λ and Σ0 baryons is delivered - both helicity dependent and unpolarised. The analysis reveals impacts of diquark correlations and SU(3)-flavour symmetry breaking, some of which are significant. For instance, were it not for the presence of axialvector diquarks in the Σ0, the strange quark could carry none of...
We report on a global fit of neutral-current elastic (NCE) neutrino-scattering data and parity-violating electron-scattering (PVES) data with the goal of determining the strange quark contribution to the vector and axial form factors of the proton. Knowledge of the strangeness contribution to the axial form factor, $G_A^s(Q^2)$, at low $Q^2$ will reveal the strange quark contribution to the...
Quarkonium production and polarization serves as a vital testing ground for quantum chromodynamics (QCD), offering critical insights into both perturbative and nonperturbative dynamics. In the nonrelativistic QCD (NRQCD) factorization framework, inclusive production cross sections of quarkonia are expressed as products of perturbatively calculable short-distance coefficients (SDCs) and...
Supposing there exists an effective charge which defines an evolution scheme for both unpolarised and polarised parton distribution functions (DFs) that is all-orders exact and using Ansätze for hadron-scale proton polarised valence quark DFs, constrained by flavour-separated axial charges and insights from perturbative quantum chromodynamics, predictions are delivered for all proton polarised...
The unpolarized and polarized gluon parton distribution functions are calculated in lattice QCD using the Large-Momentum Effective Theory(LaMET) method. The calculations are carried out at three different lattice spacings and pion mass around 300MeV. The results are extrapolated to the continuum and infinite momentum limits. The unpolarized gluon PDF is consistent with the global fit of CT18NNLO.
We use the ensemble C24P29 provided by the CLQCD collaboration, insert the topological current using the proton external state of the momentum smear under the Coulomb gauge of the 5-HYP smear, extract the matrix elements to calculate the gluon helicity under lattice QCD, and the calculation proves that different components of the topological currents ($K^z$ and $K^t$) can be used to give...
We propose a ``blending" algorithm that projects the all-to-all fermion propagator onto spatial low-frequency modes (LFM) combined with a stochastic estimate of spatial high-frequency modes (SHFM) at each time slice.
This approach enables the calculation of arbitrary-point correlation functions for arbitrary hadron states in strongly interacting quantum field theories (QFT) with fermions,...
Using continuum Schwinger function methods and the Drell-Levy-Yan relation, this work provides a unified description for pion and kaon distribution functions and fragmentation functions (FFs). After evolution to higher scale, the obtained FFs conform with a range of physical expectations for FF behaviour on the endpoint domains, such as that nonsignlet FFs vanish at z=0 and singlet FFs diverge...
We present the first global analysis of fragmentation functions (FFs) for light charged hadrons ($\pi^\pm, K^\pm$) at full next-to-next-to-leading order in QCD, incorporating world data from both single-inclusive electron-positron annihilation and semi-inclusive deep-inelastic scattering. The collinear factorization has been tested with low-momentum-transfer data and has demonstrated success...
I will report our recent results on proton spin structure from a light-front Hamiltonian approach. In this approach we obtain the light-front wave function of the proton through solving the eigenvalue problem of the light-front Hamiltonian of QCD in a basis based on the Fock-sector expansion. Then using the obtained light-front wave function we calculate the observables characterizing the spin...
Our study, rooted in hadron physics, addresses the incomplete information limitation of traditional parton distribution functions. We investigate the six-dimensional (6D) light-front Wigner distribution function of the proton (a spin-1/2 hadron) using the 6D light-front Wigner distribution framework constructed by our team.
At the leading twist, 16 independent distribution functions...
We employ the VQCD model, a holographic approach that dynamically simulates essential QCD characteristics, including linear mass spectra, confinement, asymptotic freedom, and magnetic charge screening, while incorporating quark flavor effects. Using this model, we first calculate the proton mass spectrum and the wave function, incorporating anomalous dimensions to refine our
results. Next, we...
Understanding the three-dimensional spin structure of the nucleon is one of the key questions in QCD. Among the transverse-momentum-dependent (TMD) PDFs, the TMD helicity distributions in particular are poorly constrained. Measurements of the longitudinal single-spin asymmetry ($A_L$) of $W^\pm$ bosons in polarized proton-proton collisions at RHIC provides a unique opportunity for accessing...
