We compute the matrix elements of the energy-momentum tensor of the nucleon using four ensembles of twisted mass clover-improved fermions with the up, down, strange and charm quark masses tuned to approximately their physical values. The four ensembles have similar physical volume and lattice spacings $a=0.080$~fm, $0.068$~fm, $0.057$~fm, and $0.049$ fm, allowing us to take the continuum limit directly at the physical pion mass point. We compute both connected and disconnected quark contributions as well as gluon contributions. All renormalization functions, including the mixing of the quark singlet with the gluon, are determined non-perturbatively. We extract the gravitational form factors in the continuum limit at $Q^2=0$ and evaluate the contribution of quarks and gluons to the momentum and angular momentum of the proton. Using the values of the intrinsic quark spin computed using the same gauge ensembles we also determine the orbital angular momentum for each quark flavor.
Spatial correlation functions of quarkonia in the quark-gluon plasma are available from finite- temperature lattice-QCD with good precision. However, their interpretation in terms of microscopic spectral functions has been challenging due to a highly oscillating momentum integral in their Fourier transform and the need...
The theoretical prediction of the muon anomalous magnetic moment $a_\mu$ depends crucially on the Hadronic Vacuum Polarization (HVP), and the tension between its dispersive and lattice-QCD determinations remains unresolved. We show that part of this puzzle can be addressed in the heavy-quark sector, where both descript...
Arnau Beltran, Pere Masjuan, Antonio Rivera· 1 citation
The energy-momentum tensor provides a unique insight into the internal gravitational structure of the proton by revealing how energy, momentum, and mechanical properties are distributed among its different QCD components. The gravitational form factors associated with different components of the QCD energy-momentum ten...
We investigate the gravitational $D$-form factors of the nucleon and pion within an extended linear sigma model (eLSM) that incorporates both two-quark and four-quark states, as well as nucleon fields. Within the scalar-meson-dominance picture, we find that meson mixing between two-quark and four-quark states suppresse...
Mamiya Kawaguchi, Yao Ma, Yong-Liang Ma· 0 citations
Heavy-quark spin dynamics in the quark-gluon plasma provides a potential probe of the interaction between heavy quarks and the medium. We develop a stochastic framework in which the random momentum kicks responsible for heavy-quark diffusion also induce spin rotation through Thomas precession. Starting from the Thomas-...
Ankit Kumar, Sourav Dey, Vinod Chandra et al.· 0 citations
Heavy-flavor jets and their substructure provide a unique window into the role of quark mass on QCD radiation and its modification in nuclear matter. In this work, we investigate heavy-quark energy-energy correlators (EECs) that are explicitly sensitive to mass effects, focusing on angular distributions, energy flow, a...
I. Vitev· 0 citations
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