PaperPanorama

Nuclear Theory·nucl-th

Friday·May 29, 2026

9 papers6 primary·3 cross-listed

  1. 07

    First steps towards gauge-independent vortex identification through machine learning

    Wyatt A. Smith🇺🇸 · César Fernández-Ramírez🇪🇸 · Jeff Greensite🇺🇸 · Adam P. Szczepaniak🇺🇸

    As a first step towards machine identification of confining objects in thermalized lattice gauge configurations, we present our 2dVoId model for center vortex identification on pure SU(2) lattices in dimensions. We create a training set by inserting thin Z2 vortices at various locations on a zero action lattice, and then distort those configurations by applying random SU(2) gauge transformations, noise, and by thickening the vortices via cooling. For moderate vortex visibility, our model is able to reliably identify the location of center vortices. We additionally demonstrate scalability through tiling strategies, which will enable generalization to higher dimensions while reducing training costs.

    hep-latnucl-th0 citations
  2. 08

    Higher Mellin Moments of the Unpolarized PDF of the Pion and the Kaon from Lattice QCD

    Constantia Alexandrou (Univ. of Cyprus and The Cyprus Inst.)🇨🇾 · Simone Bacchio (The Cyprus Inst.)🇨🇾 · Priyajit Jana (Univ. of Cyprus and The Cyprus Inst.)🇨🇾 · Marcus Petschlies (Univ. of Bonn)🇩🇪 · Luis Alberto Rodriguez Chacon (The Cyprus Inst. and Univ. of Ferrara)🇨🇾 · Gregoris Spanoudes (Univ. of Cyprus)🇨🇾 · Fernanda Steffens (Univ. of Bonn)🇩🇪 · Carsten Urbach (Univ. of Bonn)🇩🇪 · Urs Wenger (Univ. of Bern)🇨🇭

    We present results on the Mellin moments of the unpolarized parton distribution function (PDF) of the pion and kaon up to the fourth order. The computation is done using one gauge ensemble of twisted mass fermions with quark masses tuned to approximately their physical values. We reconstruct the valence pion and kaon PDFs using the connected contributions to the three Mellin moments. We compare our results on the Mellin moments and the reconstructed PDFs with other lattice QCD and phenomenological determinations.

    hep-lathep-exhep-phnucl-th3 citations
  3. 09

    Mellin Moments of the Unpolarized Gluon PDF in the Proton from Nonlocal Operators in Lattice QCD

    Joseph Delmar🇺🇸 · Krzysztof Cichy🇵🇱 · Martha Constantinou🇺🇸 · Yong Zhao🇺🇸

    We present a lattice QCD determination of the Mellin moments of the unpolarized gluon parton distribution function in the proton. The analysis is based on matrix elements of nonlocal gluon operators coupled to momentum-boosted proton states. The calculation relies on an ensemble of maximally twisted mass fermions with clover improvement and the Iwasaki-improved gauge action, at a pion mass of approximately 260 MeV. Working within the short-distance operator product expansion (OPE) of the reduced gluon Ioffe-time distribution, we extract ratios of higher-order gluon moments, with , to the gluon momentum fraction, . We investigate systematic effects associated with the truncation of the order of moment in the OPE, the choice of minimum and maximum Wilson-line separations entering the analysis, and the treatment of mixing with the quark-singlet under perturbative matching. The stability of the extracted moments is further studied under scale evolution using DGLAP equations, allowing us to assess uncertainties related to perturbative truncation by varying the scale. Our work provides a determination of the ratio at a scale of 2 GeV, with uncertainties that account for both statistical and the dominant theoretical systematic uncertainties.

    hep-lathep-phhep-thnucl-th1 citation

Affiliations

first authorsco-authorsvia INSPIRE