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Related papers: Two-loop matching of the chromo-magnetic dipole op…

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The quark chromoelectric dipole (qCEDM) operator is a CP-violating operator describing, at hadronic energies, beyond-the-standard-model contributions to the electric dipole moment of particles with nonzero spin. In this paper we define…

High Energy Physics - Lattice · Physics 2022-04-15 Emanuele Mereghetti , Christopher J. Monahan , Matthew D. Rizik , Andrea Shindler , Peter Stoffer

The gradient-flow formulation of the energy-momentum tensor of QCD is extended to NNLO perturbation theory. This means that the Wilson coefficients which multiply the flowed operators in the corresponding expression for the regular…

High Energy Physics - Lattice · Physics 2025-05-14 Robert V. Harlander , Yannick Kluth , Fabian Lange

The gradient-flow formalism proves to be a useful tool in lattice calculations of quantum chromodynamics. For example, it can be used as a scheme to renormalize composite operators by inverting the short-flow-time expansion of the…

High Energy Physics - Lattice · Physics 2024-11-05 Janosch Borgulat , Robert V. Harlander , Jonas T. Kohnen , Fabian Lange

We describe in detail the implementation of a systematic perturbative approach to observables in the QCD gradient-flow formalism. This includes a collection of all relevant Feynman rules of the five-dimensional field theory and the…

High Energy Physics - Lattice · Physics 2022-10-12 Johannes Artz , Robert V. Harlander , Fabian Lange , Tobias Neumann , Mario Prausa

We evaluate the three-loop matching conditions for the dimension-five operators that are relevant for the b -> s gamma decay. Our calculation completes the first out of three steps (matching, mixing and matrix elements) that are necessary…

High Energy Physics - Phenomenology · Physics 2010-04-05 Mikolaj Misiak , Matthias Steinhauser

The gradient-flow operator product expansion for QCD current correlators including operators up to mass dimension four is calculated through NNLO. This paves an alternative way for efficient lattice evaluations of hadronic vacuum…

High Energy Physics - Lattice · Physics 2021-08-26 Robert V. Harlander , Fabian Lange , Tobias Neumann

The translation of experimental limits on the neutron electric dipole moment into constraints on heavy $CP$-violating physics beyond the Standard Model requires knowledge about non-perturbative matrix elements of effective operators, which…

High Energy Physics - Lattice · Physics 2023-08-31 Jona Bühler , Peter Stoffer

In this proceedings, we lay the foundation for computing the contribution of quark chromo-electric dipole moment (qCEDM) operator to the nucleon electric dipole moment. By applying the gradient flow technique, we can parameterize the…

High Energy Physics - Lattice · Physics 2018-10-25 Jangho Kim , Jack Dragos , Andrea Shindler , Thomas Luu , Jordy de Vries

When QCD is described by a nonrelativistic effective field theory, operators consisting of gluonic correlators of two chromoelectric or -magnetic fields will often appear in descriptions of quarkonium physics. At zero T, these correlators…

High Energy Physics - Lattice · Physics 2024-01-15 Viljami Leino

Recently, Harlander et al.\ [Eur.\ Phys.\ J.\ C {\bf 78}, 944 (2018)] have computed the two-loop order (i.e., NNLO) coefficients in the gradient-flow representation of the energy--momentum tensor (EMT) in vector-like gauge theories. In this…

High Energy Physics - Lattice · Physics 2019-12-06 Takumi Iritani , Masakiyo Kitazawa , Hiroshi Suzuki , Hiromasa Takaura

The effective electroweak Hamiltonian in the gradient-flow formalism is constructed for the current-current operators through next-to-next-to-leading order QCD. The results are presented for two common choices of the operator basis. This…

High Energy Physics - Lattice · Physics 2023-03-14 Robert V. Harlander , Fabian Lange

The calculation of the neutron electric dipole moment within effective field theories for physics beyond the Standard Model requires non-perturbative hadronic matrix elements of effective operators composed of quark and gluon fields. In…

High Energy Physics - Lattice · Physics 2023-11-17 Òscar L. Crosas , Christopher J. Monahan , Matthew D. Rizik , Andrea Shindler , Peter Stoffer

We present the complete one-loop matching of the baryon- and lepton-number-conserving low-energy effective field theory (LEFT) to the QCD gradient flow. Using Euclidean conventions and the background-field formulation of the gradient flow,…

High Energy Physics - Phenomenology · Physics 2026-01-28 Òscar L. Crosas , Peter Stoffer

In a recently published work we employ gradient flow on the lattice to extract the leading contribution of the heavy quark momentum diffusion coefficient in the heavy quark limit from calculations of a well-known two-point function of…

High Energy Physics - Lattice · Physics 2023-07-14 Luis Altenkort , Alexander M. Eller , Olaf Kaczmarek , Lukas Mazur , Guy D. Moore , Hai-Tao Shu

The order $\alpha_s$ corrections to the Wilson coefficients of the dipole operators ($O_7,O_8$) at the matching scale $\mu =m_W$ are a crucial ingredient for a complete next- to-leading logarithmic calculation of the branching ratio for $b…

High Energy Physics - Phenomenology · Physics 2014-11-17 Christoph Greub , Tobias Hurth

In this paper we consider the matching coefficients up to two loops between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) for the vector, axial-vector, scalar and pseudo-scalar currents. The structure of the effective theory…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. A. Kniehl , A. Onishchenko , J. H. Piclum , M. Steinhauser

The transfer operator associated to a flow (continuous time dynamical system) is a one-parameter operator semigroup. We consider the operator-valued Laplace transform of this one-parameter semigroup. Estimates on the Laplace transform have…

Dynamical Systems · Mathematics 2019-02-20 Oliver Butterley

We utilize the gradient flow to define and calculate electric dipole moments induced by the strong QCD $\theta$-term and the dimension-6 Weinberg operator. The gradient flow is a promising tool to simplify the renormalization pattern of…

High Energy Physics - Lattice · Physics 2018-04-18 Jack Dragos , Thomas Luu , Andrea Shindler , Jordy de Vries

We calculate the two-loop QCD mixing of the dimension-five flavor-changing operators that arise in the Standard Model after integrating out the $W$, $Z$ and Higgs bosons and the top-quark, i.e.~the mixing among gluonic and photonic magnetic…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. Misiak , M. Muenz

We present preliminary results on the susceptibilities involving the CP-violating (CPV) Weinberg three-gluon operator and the topological $\Theta$ term using the gradient flow scheme, and study their continuum and chiral extrapolations.…

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