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Related papers: Two-Loop Fermionic Integrals in Perturbation Theor…

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We present the fermionic universal one--loop effective action obtained by integrating out heavy vector--like fermions at one loop using functional techniques. Even though previous approaches are able to handle integrating out heavy fermions…

High Energy Physics - Phenomenology · Physics 2021-02-03 Andrei Angelescu , Peisi Huang

We numerically evaluate the one-loop counterterms for the four-dimensional Wess-Zumino model formulated on the lattice using Ginsparg-Wilson fermions of the overlap (Neuberger) variety, together with an auxiliary fermion (plus…

High Energy Physics - Lattice · Physics 2014-11-21 Chen Chen , Eric Dzienkowski , Joel Giedt

We present results for the renormalization of gauge invariant nonlocal fermion operators which contain a Wilson line, to one loop level in lattice perturbation theory. Our calculations have been performed for Wilson/clover fermions and a…

High Energy Physics - Lattice · Physics 2018-04-18 M. Constantinou , H. Panagopoulos

We calculate the two loop Landau mean links and the one loop renormalisation of the anisotropy for Wilson and improved SU(3) gauge actions, using twisted boundary conditions as a gauge invariant infrared regulator. We show these accurately…

High Energy Physics - Lattice · Physics 2009-11-07 I. T. Drummond , A. Hart , R. R. Horgan , L. C. Storoni

We present a new program package for calculating one-loop Feynman integrals, based on a new method avoiding Feynman parametrization and the contraction due to Passarino and Veltman. The package is calculating one-, two- and three-point…

High Energy Physics - Phenomenology · Physics 2011-04-20 L. Brücher , J. Franzkowski , D. Kreimer

The treatment of hypercubic lattice artifacts is essential for the calculation of non-perturbative renormalization constants of RI-MOM schemes. It has been shown that for the RI'-MOM scheme a large part of these artifacts can be calculated…

High Energy Physics - Lattice · Physics 2015-01-27 Jakob Simeth , Andre Sternbeck , Meinulf Gockeler , Holger Perlt , Arwed Schiller

We discuss N=2 supersymmetric quantum mechanics on the lattice using the fermion loop formulation. In this approach the system naturally decomposes into a bosonic and fermionic sector. This allows us to deal with the sign problem arising in…

High Energy Physics - Lattice · Physics 2015-03-19 David Baumgartner , Urs Wenger

We give the correct analytic expression of a finite integral appearing in the four-loop computation of the renormalization-group functions for the two-dimensional nonlinear sigma-model on the square lattice with standard action, explaining…

High Energy Physics - Lattice · Physics 2009-10-31 B. Alles , S. Caracciolo , A. Pelissetto , M. Pepe

We study operator insertions into 1/2 BPS Wilson loops in N = 6 ABJM theory and investigate their two-point correlators. In this framework, the energy emitted by a heavy moving probe can be exactly obtained from some two-point coefficients…

High Energy Physics - Theory · Physics 2017-12-05 Lorenzo Bianchi , Luca Griguolo , Michelangelo Preti , Domenico Seminara

We compute the Schroedinger functional (SF) for the case of lattice QCD with Wilson fermions (with and without SW improvement) at two-loop order in lattice perturbation theory. This allows us to extract the three-loop beta-function in the…

High Energy Physics - Lattice · Physics 2008-11-26 Achim Bode , Peter Weisz , Ulli Wolff

We compute, to two loops in pertubation theory, the fermionic contribution to rectangular RxT Wilson loops, for different values of R and T. We use the overlap fermionic action. We also employ the clover action, for comparison with existing…

High Energy Physics - Lattice · Physics 2016-09-01 A. Athenodorou , H. Panagopoulos

We investigate massless n-point one-loop amplitudes of the open RNS superstring with two external fermions and determine their worldsheet integrands. The contributing correlation functions involving spin-1/2 and spin-3/2 operators from the…

High Energy Physics - Theory · Physics 2018-06-21 Seungjin Lee , Oliver Schlotterer

We present a new program package for calculating one-loop Feynman integrals, based on a new method avoiding Feynman parametrization and the contraction due to Passarino and Veltman. The package is calculating one-, two- and three-point…

High Energy Physics - Phenomenology · Physics 2007-05-23 Lars Brucher , Johannes Franzkowski

We discuss the lattice formulation of gauge theories with fermions in arbitrary representations of the color group, and present the implementation of the RHMC algorithm for simulating dynamical Wilson fermions. A first dataset is presented…

High Energy Physics - Lattice · Physics 2010-01-21 Luigi Del Debbio , Agostino Patella , Claudio Pica

Framing plays a central role in the evaluation of Wilson loops in theories with Chern-Simons actions. In pure Chern-Simons theory, it guarantees topological invariance, while in theories with matter like ABJ(M), our theory of interest, it…

High Energy Physics - Theory · Physics 2024-12-10 Marco S. Bianchi , Luigi Castiglioni , Silvia Penati , Marcia Tenser , Diego Trancanelli

Two cluster algorithms, based on constructing and flipping loops, are presented for worldline quantum Monte Carlo simulations of fermions and are tested on the one-dimensional repulsive Hubbard model. We call these algorithms the loop-flip…

Condensed Matter · Physics 2007-05-23 N. Kawashima , J. E. Gubernatis , H. G. Evertz

Ab initio predictions of two-loop electroweak contributions to observables are increasingly essential for precision collider experiments, yet their evaluation remains very challenging. We connect recurrence techniques and dispersive method…

High Energy Physics - Phenomenology · Physics 2026-04-16 A. Aleksejevs , S. Barkanova , A. I. Davydychev

We revisit the contributions of order $\alpha^2(Z\alpha)^5m$ and $\alpha^2(Z\alpha)E_F$, respectively, to the Lamb shift and to the hyperfine splitting from mixed self-energy-vacuum-polarization diagrams, involving fermionic loop. We use…

High Energy Physics - Phenomenology · Physics 2023-08-16 Petr A. Krachkov , Roman N. Lee

A mixture of spin-1/2 fermionic atoms and molecules of paired fermionic atoms is studied in an optical lattice. The molecules are formed by an attractive nearest-neighbor interaction. A functional integral is constructed for this many-body…

Other Condensed Matter · Physics 2017-08-23 O. Fialko , K. Ziegler

We give a simplified proof for the equivalence of loop-erased random walks to a lattice model containing two complex fermions, and one complex boson. This equivalence works on an arbitrary directed graph. Specifying to the $d$-dimensional…

Statistical Mechanics · Physics 2020-11-04 Assaf Shapira , Kay Jörg Wiese