Conveners
Structure of hadrons and nuclei
- Kehfei Liu
Structure of hadrons and nuclei
- Dimitra Pefkou
Structure of hadrons and nuclei
- Marcel Rodekamp (Universität Regensburg)
Structure of hadrons and nuclei
- There are no conveners in this block
Structure of hadrons and nuclei
- Gunnar Bali (Universität Regensburg)
Structure of hadrons and nuclei
- Christopher Monahan
The hadronic tensor is the central non-perturbative object in the calculation of the cross section of lepton-hadron interactions like neutrino-nucleon scattering. It is usually parameterized in terms of structure functions, which encode all necessary information independently of the kinematic region. Moreover, the hadronic tensor can be factorized in terms of parton distribution functions...
Using forward matrix elements of local leading twist operators, we present a determination of the third Mellin moments $\left< x^2 \right>$ of nucleon's unpolarized, polarized and transversity parton distribution functions.
Two lattice QCD ensembles at the physical pion mass are used: these were generated using a tree-level Symanzik-improved gauge action and $2+1$ flavor tree-level improved...
The HadStruc collaboration is pursuing a program aimed at understanding the three-dimensional internal structure of the nucleon encapsulated in the Generalized Parton Distributions (GPDs) and Generalized Form Factors (GFFs) within the short-distance factorization approach. I present recent work by HadStruc on the isovector GFFs of the nucleon, including those corresponding to non-zero...
The light-cone distribution amplitude (LCDA) is a fundamental non-perturbative quantity for understanding hadron structure. We report on our calculation of the pion and kaon LCDAs using the heavy-quark operator product expansion (HOPE) framework. This method employs an OPE analysis of hadronic amplitudes through the inclusion of a fictitious valence heavy quark, and has previously been shown...
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 rich internal structure of hadrons is encoded in partonic functions, such as parton distribution functions (PDFs) and light-cone distribution amplitudes (LCDAs), which are crucial in collider experiments and decay processes. Calculating them from first principles remains a major challenge: they require matrix elements with a Wilson line along a light-like direction, which is not directly...
Understanding a hadron’s electric and magnetic polarizabilities allows one to access internal structural information. Traditionally, the external field two-point function method has been used to calculate polarizabilities. However, recent work has demonstrated the effectiveness of using four-point functions for computing polarizabilities of charged and neutral hadrons. Our previous study on...
Instanton liquid model is believed to capture the main features of vacuum QCD dynamics. Recently, multiple predictions for hadron structure functions have been derived and compared with experimental measurements and lattice QCD calculations, finding a general agreement. In order to explore the precision of the instanton liquid model, one has to compare its predictions with non-perturbative...
The calculation of the hadronic form factors on the lattice provides important information about the internal structure of the corresponding states. However, calculating the form factor for unstable states, viz. resonances, is not as straightforward, both from the conceptual point of view and in terms of technical implementation. In this work, we specifically consider the electromagnetic form...
We present the results of the nucleon axial-vector charge based on PACS10 gauge ensembles. These ensembles are generated by PACS Collaboration using stout-smeared O(a) improved Wilson-clover quark action and Iwasaki gauge action, and they are characterized by the spatial extent of 10 fm and three lattice spacings 0.09 fm, 0.06 fm and 0.04 fm. In particular, the latest update at 0.04 fm is...
We present an update on the Los Alamos collaborations' calculations of the spectrum, charges, form-factors, and electric dipole moments of nucleons using lattice QCD. Our calculations are done using Wilson-Clover fermions on both Clover and MILC collaboration's HISQ gauge configurations. These ensembles include multiple lattice spacings down to 0.04 fm, and multiple isospin-symmetric pion...
The determination of the lattice scale with high precision is a prerequisite for extracting reliable physical results from lattice QCD. We present an analysis of scale setting using 2+1-flavor Wilson–clover ensembles generated by the JLab/W&M/LANL/MIT/Marseille collaborations with the Hybrid Monte Carlo algorithm. These ensembles span a broad range of lattice spacings ($0.056 \leq a \leq...
We present progress towards a high-precision lattice QCD study of the nucleon’s isovector vector form factors, which encode key aspects of the nucleon’s spatial structure and its response to electromagnetic probes. We utilize the Coordinated Lattice Simulations (CLS) ensembles generated with $N_f =2+1$ non-perturbatively $O(a)$ improved Wilson fermions and a tree-level Symanzik-improved gauge...
We present our work on the computation of the axial form factor of the nucleon from lattice QCD. We employ a set of $N_f=2+1$ CLS ensembles with $O(a)$-improved Wilson fermions and the Lüscher-Weisz gauge action, with lattice spacings ranging from $0.05\,\text{fm}$ to $0.086\,\text{fm}$ and pion masses spanning between $130\,\text{MeV}$ and $350\,\text{MeV}$. To control excited-state effects,...
We present the strange electromagnetic form factors of the nucleon using lattice QCD with $N_f=2+1+1$ twisted mass clover-improved fermions and quark masses tuned to their physical values. Using four ensembles with lattice spacings of $a=0.080$ fm, $0.068$ fm, $0.057$ fm and $0.049$ fm, and similar physical volume, we obtain the continuum limit directly at the physical point. The disconnected...
Higher-twist effects reflect the physics of quark-quark and quark-gluon correlations that provide unique insights into the dynamics inside hadrons that goes beyond the parton model. These effects are sub-leading (suppressed by powers of $1/Q^2$) but crucial for quantitative analyses and precision tests of QCD. By their nature higher-twist contributions are non-perturbative. In this...
The Collins-Soper (CS) kernel may be obtained through the TMD soft function by formulating the Wilson line in terms of 1-dimensional auxiliary fermion fields on the lattice. Our computation takes place in the region of the lattice that corresponds to the “spacelike” region in Minkowski space, i.e., Collins' scheme. We explore two methods for obtaining the CS kernel. The "ratio method"; which...
We present a lattice QCD calculation of the Collins-Soper kernel, which governs the rapidity evolution of transverse-momentum-dependent (TMD) distributions, using Large Momentum Effective Theory (LaMET). Quasi-TMD wave functions are computed with three meson momenta on CLQCD configurations (multiple lattice spacings) employing clover quarks and varied hadronic states. HYP smearing is applied...
