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200 papers

In this and a set of companion whitepapers, the USQCD Collaboration lays out a program of science and computing for lattice gauge theory. These whitepapers describe how calculation using lattice QCD (and other gauge theories) can aid the…

High Energy Physics - Lattice · Physics 2019-11-26 Bálint Joó , Chulwoo Jung , Norman H. Christ , William Detmold , Robert G. Edwards , Martin Savage , Phiala Shanahan

Quantum chromodynamics, most commonly referred to as QCD, is a relativistic quantum field theory for the strong interaction between subatomic particles called quarks and gluons. The most systematic way of calculating the strong interactions…

High Energy Physics - Lattice · Physics 2017-06-06 Dean P. Thomas , Rita Borgo , Robert S. Laramee , Simon J. Hands

I review the basic ideas behind lattice QCD calculations that involve charm and bottom quarks. I report on the progress in getting the correct hyperfine splitting in charmonium from lattice QCD. Some of the basic technology behind numerical…

High Energy Physics - Lattice · Physics 2017-08-23 Craig McNeile

Particle physics underpins our understanding of the world at a fundamental level by describing the interplay of matter and forces through gauge theories. Yet, despite their unmatched success, the intrinsic quantum mechanical nature of gauge…

We present a new method for determining K --> pi pi matrix elements from lattice simulations that is less costly than direct simulations of K --> pi pi at physical kinematics. It improves, however, upon the traditional "indirect'' approach…

High Energy Physics - Lattice · Physics 2011-07-13 Jack Laiho , Ruth S. Van de Water

Over the past few years new physics methods and algorithms as well as the latest supercomputers have enabled the study of the QCD thermodynamic phase transition using lattice gauge theory numerical simulations with unprecedented control…

High Energy Physics - Lattice · Physics 2015-10-28 R. A. Soltz , C. DeTar , F. Karsch , Swagato Mukherjee , P. Vranas

We show that maximally twisted mass fermions can be employed to regularize on the lattice the fully unquenched QCD+QED theory with vanishing $\theta$-term. We discuss how the critical mass of the up and down quarks can be conveniently…

High Energy Physics - Lattice · Physics 2016-12-08 Roberto Frezzotti , Giancarlo Rossi , Nazario Tantalo

We present the results of 1+1+1 flavor QCD+QED simulation at the physical point, in which the dynamical quark effects in QED and the up-down quark mass difference are incorporated by the reweighting technique. The physical quark masses…

High Energy Physics - Lattice · Physics 2015-06-05 S. Aoki , K. -I. Ishikawa , N. Ishizuka , K. Kanaya , Y. Kuramashi , Y. Nakamura , Y. Namekawa , M. Okawa , Y. Taniguchi , A. Ukawa , N. Ukita , T. Yoshie

qcombo is a Python package for the symbolic evaluation of commutators between general quantum many-body operators expressed in normal-ordered form using the generalized Wick theorem. The package provides an automated and systematic…

Nuclear Theory · Physics 2026-03-26 L. H. Chen , Y. Li , H. Hergert , J. M. Yao

We introduce QCLAB, an object-oriented MATLAB toolbox for constructing, representing, and simulating quantum circuits. Designed with an emphasis on numerical stability, efficiency, and performance, QCLAB provides a reliable platform for…

Quantum Physics · Physics 2025-03-06 Sophia Keip , Daan Camps , Roel Van Beeumen

Moments of the quark density distribution, moments of the quark helicity distribution, and the tensor charge are calculated in full QCD. Calculations of matrix elements of operators from the operator product expansion have been performed on…

High Energy Physics - Lattice · Physics 2008-11-26 D. Dolgov , R. Brower , S. Capitani , J. W. Negele , A. Pochinsky , D. Renner , N. Eicker , T. Lippert , K. Schilling , R. G. Edwards , U. M. Heller

We compute the condensate in QCD with a single quark flavor using numerical simulations with the overlap formulation of lattice fermions. The condensate is extracted by fitting the distribution of low lying eigenvalues of the Dirac operator…

High Energy Physics - Theory · Physics 2009-11-11 Thomas DeGrand , Roland Hoffmann , Stefan Schaefer , Zhaofeng Liu

TBTK is a software development kit for quantum mechanical calculations and is designed to enable the development of applications that investigate problems formulated on second-quantized form. It also enables method developers to create…

Quantum Physics · Physics 2019-03-12 Kristofer Björnson

In this paper we present the {\tt C++} package {\tt CRunDec} which implements all relevant formulae needed for the running and decoupling for the strong coupling constant and light quark masses. Furthermore, several formulae are implemented…

High Energy Physics - Phenomenology · Physics 2015-06-04 Barbara Schmidt , Matthias Steinhauser

We compute the condensate in QCD with two flavors of dynamical fermions using numerical simulation. The simulations use overlap fermions, and the condensate is extracted by fitting the distribution of low lying eigenvalues of the Dirac…

High Energy Physics - Lattice · Physics 2014-11-17 Thomas DeGrand , Zhaofeng Liu , Stefan Schaefer

We present a software package DiracQ, for use in quantum many-body Physics. It is designed for helping with typical algebraic manipulations that arise in quantum Condensed Matter Physics and Nuclear Physics problems, and also in some…

Strongly Correlated Electrons · Physics 2026-01-16 John G. Wright , B. Sriram Shastry

Simulating the real-time dynamics of quantum field theories (QFTs) is one of the most promising applications of quantum simulators. Regularizing a bosonic QFT for quantum simulation purposes typically involves a truncation in Hilbert space…

Quantum Physics · Physics 2025-09-01 Gabriele Calliari , Marco Di Liberto , Hannes Pichler , Torsten V. Zache

We introduce a new computer algebra system optimized for use in lattice perturbation theory as well as continuum perturbation theory and a new framework to perform automated perturbative calculations on top of said computer algebra system.…

High Energy Physics - Lattice · Physics 2012-11-19 Christoph Lehner

We present a generalized equations-of-motion method that efficiently calculates energy spectra and matrix elements for algebraic models. The method is applied to a 5-dimensional quartic oscillator that exhibits a quantum phase transition…

Nuclear Theory · Physics 2008-11-26 S. Y. Ho , G. Rosensteel , D. J. Rowe

Quantum electrodynamics (QED) with self-conjugated equations with spinor wave functions for fermion fields is considered. In the low order of the perturbation theory, matrix elements of some of QED physical processes are calculated. The…

General Physics · Physics 2021-08-11 V. P. Neznamov , V. E. Shemarulin