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Related papers: Proton mass decomposition

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We report contributions to the nucleon spin and momentum from light quarks calculated using dynamical domain wall fermions with pion masses down to 300 MeV and fine lattice spacing a=0.084 fm. Albeit without disconnected diagrams, we…

High Energy Physics - Lattice · Physics 2011-11-07 S. N. Syritsyn , J. R. Green , J. W. Negele , A. V. Pochinsky , M. Engelhardt , Ph. Hagler , B. Musch , W. Schroers

The exact decomposition of the proton spin has been a much debated topic, on the experimental as well as the theoretical side. In this talk we would like to report on recent non-perturbative results and ongoing efforts to explore the proton…

In this lattice QCD study we evaluate the nucleon spin decomposition to quarks and gluons contributions. We employ one gauge ensemble of maximally twisted mass fermions with two degenerate light quarks tuned to approximately reproduce the…

The production cross sections of various fragments from proton-induced reactions on $^{56}$Fe and $^{27}$Al have been analyzed by the Quantum Molecular Dynamics (QMD) plus Statistical Decay Model (SDM). It was found that the mass and charge…

We determine within lattice QCD, the nucleon spin carried by valence and sea quarks, and gluons. The calculation is performed using an ensemble of gauge configurations with two degenerate light quarks with mass fixed to approximately…

High Energy Physics - Lattice · Physics 2017-11-21 C. Alexandrou , M. Constantinou , K. Hadjiyiannakou , K. Jansen , C. Kallidonis , G. Koutsou , A. Vaquero Avilés-Casco , C. Wiese

We report the status of nucleon structure calculations on the (2+1)-flavor dynamical domain-wall fermions ensembles with pion masses as low as 180 and 250 MeV on a lattice with about 4.6 fm spatial extent. A combination of the…

High Energy Physics - Lattice · Physics 2019-08-15 Shigemi Ohta

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…

High Energy Physics - Lattice · Physics 2026-05-29 Joseph Delmar , Krzysztof Cichy , Martha Constantinou , Yong Zhao

We determine the masses, the singlet and octet decay constants as well as the anomalous matrix elements of the $\eta$ and $\eta^\prime$ mesons in $N_f=2+1$ QCD\@. The results are obtained using twenty-one CLS ensembles of non-perturbatively…

High Energy Physics - Lattice · Physics 2021-08-27 Gunnar S. Bali , Vladimir Braun , Sara Collins , Andreas Schäfer , Jakob Simeth

We report the preliminary results of lattice computation for the proton decay matrix elements in $N_f=2+1$ physical point with Wilson-clover fermion. We perform it on the PACS configurations of $64^4$ lattice volume with lattice spacing…

High Energy Physics - Lattice · Physics 2025-01-28 Ryutaro Tsuji , Yasumichi Aoki , Yoshinobu Kuramashi , Eigo Shintani

Inspired by the recent Hall C and GlueX measurements of $J/\psi$ photoproduction, a systematic analysis of the contribution of quantum anomalous energy (QAE) to the proton mass is carried out under the framework of the vector meson…

High Energy Physics - Phenomenology · Physics 2022-12-07 Xiao-Yun Wang , Jingxuan Bu , Fancong Zeng

We perform the first Lattice calculation about the charmed hadron spin decomposition using overlap fermions on a 2+1 flavor RBC/UKQCD domain-wall gauge configurations at 0.083 fm with 300 MeV pion mass. It is found that the contributions of…

High Energy Physics - Lattice · Physics 2024-10-11 Fangcheng He , Jian Liang , Yi-Bo Yang

We perform a direct calculation of the gluon momentum fraction of the nucleon using maximally twisted mass fermion ensembles with $N_f=2+1+1$ flavors at a pion mass of about $370\,\mathrm{MeV}$ and a lattice spacing of $a\approx…

Proton decay is a major prediction of Grand-Unified Theories (GUT) and its observation would indicate baryon number violation that is required for baryogenesis. Many decades of searching for proton decay have constrained its rate and ruled…

High Energy Physics - Lattice · Physics 2022-04-20 Jun-Sik Yoo , Yasumichi Aoki , Peter Boyle , Taku Izubuchi , Amarjit Soni , Sergey Syritsyn

Results on the electromagnetic form factors of the nucleon using twisted mass fermion configurations are presented. These include a gauge field ensemble simulated with two degenerate light quarks yielding a pion mass of around 130 MeV, as…

Momentum and spatial distributions of quarks and gluons inside hadrons are typically encoded in the so-called generalized parton distributions (GPDs). GPDs are multi-dimensional quantities that are very challenging to extract, both…

We compute the electromagnetic form factors of the proton and neutron using lattice QCD with $N_f = 2 + 1 + 1$ twisted mass clover-improved fermions and quark masses tuned to their physical values. Three ensembles with lattice spacings of…

High Energy Physics - Lattice · Physics 2025-02-18 Constantia Alexandrou , Simone Bacchio , Giannis Koutsou , Bhavna Prasad , Gregoris Spanoudes

We report on an analysis of the average quark momentum fraction of the nucleon and related quantities using $N_\mathrm{f}=2+1$ Wilson fermions. Computations are performed on four CLS ensembles covering three values of the lattice spacing at…

High Energy Physics - Lattice · Physics 2018-04-18 Konstantin Ottnad , Tim Harris , Harvey Meyer , Georg von Hippel , Jonas Wilhelm , Hartmut Wittig

We calculate the matrix elements of the gluonic contributions to the energy-momentum tensor for a pion of mass 600 < Mpi < 1100 MeV in quenched lattice QCD. We find that gluons contribute (37 +/- 8 +/- 12)% of the pion's light cone…

High Energy Physics - Lattice · Physics 2008-11-26 Harvey B. Meyer , John W. Negele

We present results of the x-dependence of the unpolarized gluon PDF for the proton. We use an $N_f=2+1+1$ ensemble of maximally twisted mass fermions with clover improvement and the Iwasaki improved gluon action. The quark masses are tuned…

High Energy Physics - Lattice · Physics 2022-12-23 Joseph Delmar , Constantia Alexandrou , Krzysztof Cichy , Martha Constantinou , Kyriakos Hadjiyiannakou

In this contribution, results from $N_f=2$ lattice QCD simulations at one lattice spacing using twisted mass fermions with a clover term at the physical pion mass are presented. The mass splitting between charged and neutral pions…