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Numerical simulations of processes of three and four top quark hadroproduction are carried out in the SMEFT model framework. The simulated data are used to derive expected theoretical constraints on Wilson coefficients of relevant SMEFT…

High Energy Physics - Phenomenology · Physics 2024-07-11 A. Aleshko , E. Boos , V. Bunichev , L. Dudko

The interactions between two octet baryons are studied at low energies using lattice QCD (LQCD) with larger-than-physical quark masses corresponding to a pion mass of $m_{\pi}\sim 450$ MeV and a kaon mass of $m_{K}\sim 596$ MeV. The…

We calculate perturbative renormalization constants for the \Delta B=2 four-quark operators in lattice NRQCD. Continuum operators \bar{b}\gamma_{\mu}(1-\gamma_5)q~ \bar{b}\gamma_{\mu}(1-\gamma_5)q and…

High Energy Physics - Lattice · Physics 2009-10-31 S. Hashimoto , K-I. Ishikawa , T. Onogi , M. Sakamoto , N. Tsutsui , N. Yamada

We apply the Schroedinger Functional (SF) formalism to determine the renormalisation group running of four-fermion operators which appear in the effective weak Hamiltonian of the Standard Model. Our calculations are done using Wilson…

High Energy Physics - Lattice · Physics 2009-11-07 M. Guagnelli , J. Heitger , C. Pena , S. Sint , A. Vladikas

Recently various new concepts for the construction of Dirac operators in lattice Quantum Chromodynamics (QCD) have been introduced. These operators satisfy the so-called Ginsparg-Wilson condition (GWC), thus obeying the Atiyah-Singer index…

High Energy Physics - Lattice · Physics 2011-07-19 Christof Gattringer , C. B. Lang

In lattice QCD with Wilson-type quarks, the chiral symmetry is explicitly broken by the Wilson term on finite lattices. Though the symmetry is guaranteed to recover in the continuum limit, a series of non-trivial procedures are required to…

In this talk, we motivate the calculation of the matrix elements of novel CP violating operators, the quark EDM and the quark chromo EDM operators, within the nucleon state using lattice QCD. These matrix elements, combined with the bound…

High Energy Physics - Lattice · Physics 2017-04-05 Rajan Gupta

We describe how the Schroedinger functional and twisted mass QCD can be used to compute the kaon B-parameter B_K on the lattice with Wilson fermions. This new approach is expected to reduce the systematic uncertainties on B_K through a…

High Energy Physics - Lattice · Physics 2015-06-25 M. Guagnelli , J. Heitger , C. Pena , S. Sint , A. Vladikas

The gradient-flow formalism provides a framework for the direct determination of moments of parton distribution functions (PDFs) from lattice QCD calculations. Their conversion from the gradient-flow scheme to $\overline{\text{MS}}$…

High Energy Physics - Phenomenology · Physics 2025-11-24 Robert V. Harlander , Jonas T. Kohnen , Andrea Shindler

We present one-loop matching coefficients between continuum and lattice QCD for the heavy-light four-fermion operators relevant for neutral B meson mixing both within and beyond the Standard Model. For the lattice theory we use…

High Energy Physics - Lattice · Physics 2008-11-26 Elvira Gamiz , Junko Shigemitsu , Howard Trottier

We give a determination of the phenomenological value of the Wilson (or gradient) flow scales t0 and w0 for 2+1 flavours of dynamical quarks. The simulations are performed keeping the average quark mass constant, which allows the approach…

High Energy Physics - Lattice · Physics 2015-08-25 V. G. Bornyakov , R. Horsley , R. Hudspith , Y. Nakamura , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , H. Stüben , J. M. Zanotti

We investigate the renormalization of a class of gauge-invariant nonlocal quark bilinear operators, including a finite-length Wilson-line (called Wilson-line operators). The matrix elements of these operators are involved in the recent…

High Energy Physics - Lattice · Physics 2018-11-09 Gregoris Spanoudes , Haralambos Panagopoulos

We present first results from the QCDSF collaboration for the kaon semileptonic decay form factors at zero momentum transfer, using two flavours of non-perturbatively O(a)-improved Wilson quarks. A lattice determination of these form…

High Energy Physics - Lattice · Physics 2008-11-26 QCDSF Collaboration , D. Brommel , R. Horsley , S. M. Morozov , Y. Nakamura , D. Pleiter , G. Schierholz , H. Stuben , J. M. Zanotti

Nucleon matrix elements of various four-quark operators are evaluated in quenched lattice QCD using Wilson fermions. Some of these operators give rise to twist-four contributions to nucleon structure functions. Furthermore, they bear…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , B. Klaus , D. Pleiter , P. E. L. Rakow , S. Schaefer , A. Schäfer , G. Schierholz

We analyse for the first time the CP violating ratio $\varepsilon'/\varepsilon$ in $K\to \pi\pi$ decays in leptoquark (LQ) models. Assuming a mass gap to the electroweak (EW) scale, the main mechanism for LQs to contribute to…

High Energy Physics - Phenomenology · Physics 2021-01-19 Christoph Bobeth , Andrzej J. Buras

In this paper, employing an all-to-all quark propagator technique, we investigate the kaon-nucleon interactions in lattice QCD. We calculate the S-wave kaon-nucleon potentials at the leading order in the derivative expansion in the…

High Energy Physics - Lattice · Physics 2020-09-16 Kotaro Murakami , Yutaro Akahoshi , Sinya Aoki

We calculate the mixing matrices of four-quark operators that change flavor numbers by two units. Our approach employs two schemes: the coordinate-space Gauge Invariant Renormalization Scheme (GIRS) and the Modified Minimal Subtraction…

High Energy Physics - Lattice · Physics 2025-01-27 M. Constantinou , M. Costa , H. Herodotou , H. Panagopoulos , G. Spanoudes

We numerically study the crossing symmetry constraints in 4D CFTs, using previously introduced algorithms based on semidefinite programming. We study bounds on OPE coefficients of tensor operators as a function of their scaling dimension…

High Energy Physics - Theory · Physics 2015-06-22 Francesco Caracciolo , Alejandro Castedo Echeverri , Benedict von Harling , Marco Serone

We examine the applicability of diffusive lattice Boltzmann methods to simulate the fluid transport through barrier coatings, finding excellent agreement between simulations and analytical predictions for standard parameter choices. To…

Computational Physics · Physics 2017-06-28 Kyle T. Strand , Aaron J. Feickert , Alexander J. Wagner

Lattice calculations of hadronic observables are aggravated by short-distance fluctuations. The gradient flow, which can be viewed as a particular realisation of the coarse-graining step of momentum space RG transformations, proves a…

High Energy Physics - Lattice · Physics 2021-12-14 K. U. Can , R. Horsley , Y. Nakamura , H. Perlt , P. E. L. Rakow , G. Schierholz , H. Stüben , R. D. Young , J. M. Zanotti