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Twisted mass gauge ensembles at physical values of the light, strange and charm quark masses 38

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Twisted mass gauge ensembles at physical values of the light...

38th International Symposium on Lattice Field Theory, LATTICE 2021

作者： Finkenrath, Jacob Alexandrou, Constantia Bacchio, Simone Constantinou, Martha Dimopoulos, Petros Frezzotti, Roberto Jansen, Karl Kostrzewa, Bartosz Koutsou, Giannis Rossi, Giancarlo Urbach, Carsten Wenger, Urs Computation-based Science and Technology Research Center The Cyprus Institute Nicosia 20 Constantinou Kavafi Str. Nicosia2121 Cyprus Department of Physics University of Cyprus P.O. Box 20537 Nicosia1678 Cyprus Temple University 1801 N Broad Str. PhiladelphiaPA19122 United States Dipartimento di Scienze Matematiche Fisiche e Informatiche Università di Parma INFN Gruppo Collegato di Parma Italy Dipartimento di Fisica Universita di Roma "Tor Vergata" INFN Sezione di Roma 2 Via della Ricerca Scientifica Rome00133 Italy NIC DESY Zeuthen Germany High Performance Computing and Analytics Lab Rheinische Friedrich-Wilhelms-Universität Bonn Friedrich-Hirzebruch- Allee 8 BonnD-53115 Germany Centro Fermi - Museo Storico della Fisica Centro Studi e Ricerche Enrico Fermi Compendio del Viminale Piazza del Viminiale 1 RomeI-00184 Italy Rheinische Friedrich-Wilhelms-Universität Bonn Bonn Germany Albert Einstein Center for Fundamental Physics Institute for Theoretical Physics University of Bern Sidlerstrasse 5 BernCH-3012 Switzerland

Lattice QCD simulations directly at physical masses of dynamical light, strange and charm quarks are highly desirable especially to remove systematic errors due to chiral extrapolations. However such simulations are still challenging. We discuss the adaption of efficient algorithms, like multigrid methods or higher order integrators, within the molecular dynamic steps of the Hybrid Monte Carlo algorithm, that are enabling simulations of a new set of gauge ensembles by the Extended Twisted Mass collaboration (ETMC). We present the status of the on-going ETMC simulation effort that aims to enabling studies of finite size and discretization effects. We work within the twisted mass discretization which is free of odd-discretization effects at maximal twist and present our tuning procedure. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)

关键词： Molecular dynamics

Gradient flow scale-setting with Nf = 2 + 1 + 1 Wilson-clover twisted-mass fermions 38

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Gradient flow scale-setting with Nf = 2 + 1 + 1 Wilson-clove...

38th International Symposium on Lattice Field Theory, LATTICE 2021

作者： Alexandrou, C. Bacchio, S. Bergner, G. Dimopoulos, P. Finkenrath, J. Frezzotti, R. Garofalo, M. Kostrzewa, B. Koutsou, G. labus, P. Sanfilippo, F. Simula, S. Ueding, M. Urbach, C. Wenger, U. Department of Physics University of Cyprus Nicosia20537 Cyprus Computation-Based Science and Technology Research Center The Cyprus Institute 20 Konstantinou Kavafi Street Nicosia2121 Cyprus University of Jena Institute for Theoretical Physics Max-Wien-Platz 1 JenaD-07743 Germany ParmaI-43124 Italy Dipartimento di Fisica Università di Roma "Tor Vergata" INFN Sezione di Tor Vergata Via della Ricerca Scientifica 1 RomaI-00133 Italy Rheinische Friedrich-Wilhelms-Universität Bonn Nussallee 14-16 BonnD-53115 Germany Dipartimento di Fisica Università Roma Tre INFN Sezione di Roma Tre Via della Vasca Navale 84 RomeI-00146 Italy High Performance Computing and Analytics Lab Rheinische Friedrich-Wilhelms-Universität Bonn Friedrich-Hirzebruch-Allee 8 BonnD-53115 Germany Fraunhofer-Platz 1 KaiserslauternD-67663 Germany Istituto Nazionale di Fisica Nucleare Sezione di Roma Tre Via della Vasca Navale 84 RomeI-00146 Italy Institute for Theoretical Physics Albert Einstein Center for Fundamental Physics University of Bern Sidlerstrasse 5 BernCH-3012 Switzerland

We present a determination of the gradient flow scales w0√t0 and t0/w0 in isosymmetric QCD, making use of the gauge ensembles produced by the Extended Twisted Mass Collaboration (ETMC) with N f = 2 + 1 + 1 flavours of Wilson-clover twisted-mass quarks including configurations close to the physical point for all dynamical flavours. The simulations are carried out at three values of the lattice spacing and the scale is set through the PDG value of the pion decay constant, yielding w0 = 0.17383(63) fm, √t0 = 0.14436(61) fm and t0/w0 = 0.11969(62) fm. Finally, fixing the kaon mass to its isosymmetric value, we determine the ratio of the kaon and pion leptonic decay constants to be fK/fπ = 1.1995(44). © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)

关键词： Hadrons

Nucleon transverse quark spin densities

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arXiv 2022年

作者： Alexandrou, Constantia Bacchio, Simone Constantinou, Martha Dimopoulos, Petros Finkenrath, Jacob Frezzotti, Roberto Hadjiyiannakou, Kyriakos Jansen, Karl Kostrzewa, Bartosz Koutsou, Giannis Spanoudes, Gregoris Urbach, Carsten Department of Physics University of Cyprus P.O. Box 20537 Nicosia1678 Cyprus Computation-based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus Department of Physics Temple University PhiladelphiaPA19122-1801 United States Parma43124 Italy Dipartimento di Fisica INFN Universitá di Roma Tor Vergata Via della Ricerca Scientifica 1 RomaI-00133 Italy NIC DESY Zeuthen Germany High Performance Computing and Analytics Lab Rheinische Friedrich-Wilhelms-Universität Bonn Friedrich-Hirzebruch-Allee 8 Bonn53115 Germany Bethe Center for Theoretical Physics University of Bonn Germany Helmholtz-Institut für Strahlen- und Kernphysik University of Bonn Germany

We present a calculation of the Mellin moments of the nucleon transverse quark spin densities extracted from the unpolarized and transversity generalized form factors. We use three Nf = 2 + 1 + 1 ensembles of twisted mass fermions with quark masses tuned to their physical values and lattice spacings a ∼ 0.08 fm, a ∼ 0.07 fm and a ∼ 0.06 fm and extrapolate the form factors to the continuum limit. Besides isovector densities we also include results for the tensor charge for each quark flavor using the ensemble with a ∼ 0.08 fm for which we include the disconnected contributions. © 2022, CC BY.

关键词： Approximation theory

First moments of the nucleon transverse quark spin densities using lattice QCD

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arXiv 2022年

作者： Alexandrou, C. Bacchio, S. Constantinou, M. Dimopoulos, P. Finkenrath, J. Frezzotti, R. Hadjiyiannakou, Kyriakos Jansen, K. Kostrzewa, B. Koutsou, G. Spanoudes, G. Urbach, C. Department of Physics University of Cyprus P.O. Box 20537 Nicosia1678 Cyprus Computation-based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus Department of Physics Temple University PhiladelphiaPA19122 - 1801 United States Parma43124 Italy Dipartimento di Fisica and INFN Università di Roma "Tor Vergata" Via della Ricerca Scientifica 1 RomaI-00133 Italy NIC DESY Zeuthen Germany High Performance Computing and Analytics Lab Rheinische Friedrich-Wilhelms-Universität Bonn Friedrich-Hirzebruch-Allee 8 Bonn53115 Germany Bethe Center for Theoretical Physics University of Bonn Germany Helmholtz-Institut für Strahlen- und Kernphysik University of Bonn Germany

We present a calculation of the Mellin moments of the transverse quark spin densities in the nucleon using lattice QCD. The densities are extracted from the unpolarized and transversity generalized form factors extrapolated to the continuum limit using three Nf = 2 + 1 + 1 twisted mass fermion gauge ensembles simulated with physical quark masses and spanning three lattice spacings. The first moment of transversely polarized quarks in an unpolarized nucleon shows an interesting distortion, which can be traced back to the sharp falloff of the transversity generalized form factor B¯Tn0(t). The isovector tensor anomalous magnetic moment is determined to be κT = 1.051(94), which confirms a negative and large Boer-Mulders function, h⊥1 , in the nucleon. Copyright © 2022, The Authors. All rights reserved.

关键词： Approximation theory

Nucleon axial and pseudoscalar form factors from lattice QCD at the physical point

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arXiv 2020年

作者： Alexandrou, Constantia Bacchio, S. Constantinou, M. Dimopoulos, P. Finkenrath, J. Hadjiyiannakou, K. Jansen, K. Koutsou, G. Kostrzewa, B. Leontiou, T. Urbach, C. Department of Physics University of Cyprus P.O. Box 20537 Nicosia1678 Cyprus Computation-Based Science and Technology Research Center The Cyprus Institute 20 Kavafi Str. Nicosia2121 Cyprus Department of Physics Temple University 1925 N. 12th Street PhiladelphiaPA19122-1801 United States Parma43124 Italy NIC DESY Platanenallee 6 ZeuthenD-15738 Germany High Performance Computing and Analytics Lab. University of Bonn Endenicher Allee 19A Bonn53115 Germany Department of Mechanical Engineering Frederick University Nicosia1036 Cyprus Helmholtz-Institut für Strahlen- und Kernphysik University of Bonn Bonn53115 Germany Bethe Center for Theoretical Physics University of Bonn Bonn53115 Germany

We compute the nucleon axial and induced pseudoscalar form factors using three ensembles of gauge configurations, generated with dynamical light quarks with mass tuned to approximately their physical value. One of the ensembles also includes the strange and charm quarks with their mass close to physical. The latter ensemble has large statistics and finer lattice spacing and it is used to obtain final results, while the other two are used for assessing volume effects. The pseudoscalar form factor is also computed using these ensembles. We examine the momentum dependence of these form factors as well as relations based on pion pole dominance and the partially conserved axial-vector current hypothesis. © 2020, CC BY-NC-ND.

关键词： Approximation theory

Lattice gauge ensembles and data management

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Lattice gauge ensembles and data management

39th International Symposium on Lattice Field Theory, LATTICE 2022

作者： Bali, Gunnar Bignell, Ryan Francis, Anthony Gottlieb, Steven Gupta, Rajan Kanamori, Issaku Kostrzewa, Bartosz Kotov, Andrey Yu. Kuramashi, Yoshinobu Mawhinney, Robert Schmidt, Christian Söldner, Wolfgang Sun, Peng Institut für Theoretische Physik Universität Regensburg Universitätsstr. 31 Regensburg93053 Germany Department of Physics Swansea University SwanseaSA2 8PP United Kingdom Institute of Physics National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Department of Physics Indiana University BloomingtonIN47405 United States Los Alamos National Laboratory Theoretical Division T-2 Los AlamosNM87545 United States 7-1-26 Minatojima Minamimachi Kobe650-0047 Japan High Performance Computing and Analytics Lab Rheinische Friedrich-Wilhelms-Universität Bonn Friedrich-Hirzebruch-Allee 8 Bonn53115 Germany Forschungszentrum Jülich Jülich52428 Germany Center for Computational Sciences University of Tsukuba Tsukuba305-8577 Japan Physics Department Columbia University New YorkNY10027 United States Fakultät für Physik Universität Bielefeld Universitätsstr. 25 Bielefeld33615 Germany Institute of Modern Physics Chinese Academy of Sciences Lanzhou730000 China University of Chinese Academy of Sciences Beijing100049 China

The generation of ensembles of gauge configurations is a considerable expense. The preservation and curation of these ensembles constitutes a valuable shared resource for the lattice field theory community. The organizers of Lattice 2022 dedicated a parallel session to the presentation of gauge ensembles and their generation, plans for ensemble publication and data management/storage activities of different collaborations. A summary of the twelve contributions is presented here. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).

关键词： Information management

Nucleon axial and pseudoscalar form factors from lattice QCD at the physical point

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Physical Review D 2021年第3期103卷 034509-034509页

作者： C. Alexandrou S. Bacchio M. Constantinou P. Dimopoulos J. Finkenrath K. Hadjiyiannakou K. Jansen G. Koutsou B. Kostrzewa T. Leontiou C. Urbach Department of Physics University of Cyprus P.O. Box 20537 1678 Nicosia Cyprus Computation-based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia 2121 Cyprus Department of Physics Temple University 1925 N. 12th Street Philadelphia Pennsylvania 19122-1801 USA Dipartimento di Scienze Matematiche Fisiche e Informatiche Università di Parma and Italian National Institute for Nuclear Physics Gruppo Collegato di Parma Parco Area delle Scienze 7/a (Campus) 43124 Parma Italy NIC DESY Platanenallee 6 D-15738 Zeuthen Germany High Performance Computing and Analytics Lab University of Bonn Endenicher Allee 19A 53115 Bonn Germany Department of Mechanical Engineering Frederick University 1036 Nicosia Cyprus Helmholtz-Institut für Strahlen- und Kernphysik University of Bonn 53115 Bonn Germany and Bethe Center for Theoretical Physics University of Bonn 53115 Bonn Germany

关键词： Lattice QCD Quantum chromodynamics Form factors

Lattice QCD results for the topological up-quark mass contribution: too small to rescue the mu = 0 solution to the strong CP problem

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arXiv 2021年

作者： Alexandrou, Constantia Finkenrath, Jacob Funcke, Lena Jansen, Karl Kostrzewa, Bartosz Pittler, Ferenc Urbach, Carsten Department of Physics University of Cyprus P.O. Box 20537 Nicosia1678 Cyprus Computation-Based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus Center for Theoretical Physics Co-Design Center for Quantum Advantage NSF AI Institute for Artificial Intelligence and Fundamental Interactions Massachusetts Institute of Technology 77 Massachusetts Avenue CambridgeMA02139 United States Perimeter Institute for Theoretical Physics 31 Caroline Street North WaterlooONN2L 2Y5 Canada Deutsches Elektronen-Synchrotron DESY Platanenallee 6 Zeuthen15738 Germany High Performance Computing & Analytics Lab University of Bonn Friedrich-Hirzebruch-Allee 8 Bonn53115 Germany Helmholtz Institut für Strahlen- und Kernphysik University of Bonn Nussallee 14-16 Bonn53115 Germany Bethe Center for Theoretical Physics University of Bonn Nussallee 12 Bonn53115 Germany

A vanishing Yukawa coupling of the up quark could in principle solve the strong CP problem. To render this solution consistent with current algebra results, the up quark must receive an alternative mass contribution that conserves CP symmetry. Such a contribution could be provided by QCD through non-perturbative topological effects, including instantons. In this talk, we present the first direct lattice computation of this topological mass contribution, using gauge configurations generated by the Extended Twisted Mass collaboration. We use the Iwasaki gauge action, Wilson twisted mass fermions at maximal twist, and dynamical up, down, strange and charm quarks. Our result for the topological mass contribution is an order of magnitude too small to account for the phenomenologically required up-quark mass. This rules out the "massless" up-quark solution to the strong CP problem, in accordance with previous results relying on χPT fits to lattice data. The talk is based on Ref. [1], where more details can be found. © 2021, CC BY.

关键词： Elementary particles

Moments of the nucleon transverse quark spin densities using lattice QCD

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Physical Review D 2023年第5期107卷 054504-054504页

作者： C. Alexandrou S. Bacchio M. Constantinou P. Dimopoulos J. Finkenrath R. Frezzotti K. Hadjiyiannakou K. Jansen B. Kostrzewa G. Koutsou G. Spanoudes C. Urbach Department of Physics University of Cyprus P.O. Box 20537 1678 Nicosia Cyprus Computation-based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia 2121 Cyprus Department of Physics Temple University Philadelphia Pennsylvania 19122–1801 USA Dipartimento di Scienze Matematiche Fisiche e Informatiche Università di Parma and INFN Gruppo Collegato di Parma Parco Area delle Scienze 7/a (Campus) 43124 Parma Italy Dipartimento di Fisica and INFN Università di Roma “Tor Vergata” Via della Ricerca Scientifica 1 I-00133 Roma Italy Deutsches Elektronen-Synchrotron DESY Platanenallee 6 15738 Zeuthen Germany High Performance Computing and Analytics Lab Rheinische Friedrich-Wilhelms-Universität Bonn Friedrich-Hirzebruch-Allee 8 53115 Bonn Germany Bethe Center for Theoretical Physics Rheinische Friedrich-Wilhelms Universität Bonn 53115 Bonn Germany Helmholtz-Institut für Strahlen-und Kernphysik Rheinische Friedrich-Wilhelms Universität Bonn 53115 Bonn Germany

We present the first calculation of the Mellin moments of the transverse quark spin densities in the nucleon using lattice QCD simulations with physical values of the pion mass and in the continuum limit. Specifically, we use three Nf=2+1+1 twisted mass fermion gauge ensembles each at different lattice spacings. The densities are extracted from the unpolarized and transversity generalized form factors. The first moment of transversely polarized quarks in an unpolarized nucleon shows an interesting distortion, which can be traced back to the sharp falloff of the transversity generalized form factor B¯Tn0(Q2). The isovector tensor anomalous magnetic moment is determined to be κT=1.051(94), which confirms a negative and large Boer-Mulders function, h1⊥, in the nucleon.

关键词： Nucleon distribution Particle correlations & fluctuations