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Related papers: Four quark operators for kaon bag parameter with g…

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We use the Yang-Mills gradient flow to study the mixing of CP-violating pure gauge operators in continuum QCD with special attention to Weinberg's d=6 purely gluonic operator. The gradient flow allows for a relatively clear derivation of…

High Energy Physics - Lattice · Physics 2018-11-07 Matthew Rizik , Christopher Monahan , Andrea Shindler

The gradient flow exponentially suppresses ultraviolet field fluctuations and removes ultraviolet divergences (up to a multiplicative fermionic wavefunction renormalization). It can be used to describe real-space Wilsonian renormalization…

High Energy Physics - Lattice · Physics 2022-02-21 Anna Hasenfratz , Christopher J. Monahan , Matthew D. Rizik , Andrea Shindler , Oliver Witzel

We report our results for the bag-parameter BK obtained from the quenched simulations on the lattice with Wilson fermions at three values of the lattice spacing. We implemented the method by which no subtraction of the mixing with other…

High Energy Physics - Lattice · Physics 2010-03-19 D. Becirevic , Ph. Boucaud , V. Gimenez , V. Lubicz , M. Papinutto

We report on our computation of the hadronic matrix elements of the four-quark operators needed for the study of $K^0-{\bar K^0}$ mixing beyond the Standard Model (SM). We consider nf=2+1 Domain-Wall fermions on Iwasaki gauge action with…

High Energy Physics - Lattice · Physics 2012-12-13 Nicolas Garron , Peter A Boyle , Renwick J Hudspith , Andrew T Lytle

We report a first, complete lattice QCD calculation of the long-distance contribution to the $K^+\to\pi^+\nu\bar{\nu}$ decay within the standard model. This is a second-order weak process involving two four-Fermi operators that is highly…

High Energy Physics - Lattice · Physics 2017-06-28 Ziyuan Bai , Norman H. Christ , Xu Feng , Andrew Lawson , Antonin Portelli , Christopher T. Sachrajda

Lattice simulations of Quantum Chromodynamics (QCD) enable one to calculate the low-energy properties of the strong interaction among quarks and gluons based on the first principle. The most time-consuming part of the numerical simulations…

High Energy Physics - Lattice · Physics 2026-02-17 Wei-Lun Chen , Issaku Kanamori , Hideo Matsufuru , Hartmut Neff

Our aim is to compute the lower moments of the unpolarized and polarized deep-inelastic structure functions of the nucleon on the lattice. The theoretical basis of the calculation is the operator product expansion. To construct operators…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , E. -M. Ilgenfritz , H. Perlt , P. Rakow , G. Schierholz , A. Schiller

We have technically improved the non-perturbative renormalization method, proposed by Martinelli et al., by using quark momentum sources and sinks. Composite two-fermion operators up to three derivatives have been measured for Wilson…

High Energy Physics - Lattice · Physics 2008-11-26 M. Goeckeler , R. Horsley , H. Oelrich , H. Perlt , P. E. L. Rakow , G. Schierholz , A. Schiller

We present results for the non-perturbative renormalisation of four-fermion operators with two flavours of dynamical quarks. We consider both fully relativistic left current-left current operators, and a full basis for $\Delta B=2$…

High Energy Physics - Lattice · Physics 2008-11-26 P. Dimopoulos , G. Herdoiza , F. Palombi , M. Papinutto , C. Pena , A. Vladikas , H. Wittig

In this work we calculate the renormalization of counterterms which arise in the lattice action of $N = 1$ Supersymmetric QCD (SQCD). In particular, the fine-tunings for quartic couplings are studied in detail through both continuum and…

High Energy Physics - Lattice · Physics 2024-09-17 Marios Costa , Herodotos Herodotou , Haralambos Panagopoulos

We present a preliminary study of the neutral kaon mixing bag parameter BK using two flavors of dynamical Wilson fermions. We determine the matrix element of the relevant DeltaS=2 operator by using both the conventional approach and the so…

High Energy Physics - Lattice · Physics 2007-05-23 F. Mescia , V. Gimenez , V. Lubicz , G. Martinelli , S. Simula , C. Tarantino

We renormalize generalized 3-quark operators that relate to baryon states using the method devised by Kr\"{a}nkl and Manashov at four loops in the MSbar scheme. The anomalous dimensions of the four core operators used to compute nucleon…

High Energy Physics - Phenomenology · Physics 2026-02-09 J. A. Gracey

The renormalization of the most general dimension-six four-fermion operators without power subtractions is studied at one loop in lattice perturbation theory using overlap fermions. As expected, operators with different chirality do not mix…

High Energy Physics - Lattice · Physics 2009-10-31 S. Capitani , L. Giusti

We compute the hadronic matrix elements of the four-quark operators needed for the study of $K^0-{\bar K^0}$ mixing beyond the Standard Model. We have used $n_f=2+1$ flavours of domain wall fermion (DWF) at two values of the lattice spacing…

High Energy Physics - Lattice · Physics 2015-12-18 R. J. Hudspith , N. Garron , A. T. Lytle

Renormalization factors for local vector and axial vector currents for the Wilson quark action are perturbatively calculated to one loop order including finite quark masses from the ratio of the on-shell quark matrix elements in the Feynman…

High Energy Physics - Lattice · Physics 2009-10-30 Yoshinobu Kuramashi

We present our strategy and some preliminary results for the renormalization of four-quark operators relevant for kaon physics. We follow the non-perturbative Rome-Southampton method, with both exceptional and non-exceptional kinematics. We…

High Energy Physics - Lattice · Physics 2015-03-18 Peter Boyle , Nicolas Garron

We perform the scale setting procedure of a mixed action setup consisting of valence Wilson twisted mass fermions at maximal twist on CLS ensembles with $N_f=2+1$ flavours of $O(a)$-improved Wilson sea quarks. We determine the gradient flow…

High Energy Physics - Lattice · Physics 2024-01-25 Alejandro Saez , Alessandro Conigli , Julien Frison , Gregorio Herdoíza , Carlos Pena

We study the renormalization of four-quark operators in one-loop perturbation theory. We employ a coordinate-space Gauge-Invariant Renormalization Scheme (GIRS), which can be advantageous compared to other schemes, especially in…

High Energy Physics - Lattice · Physics 2024-10-14 M. Constantinou , M. Costa , H. Herodotou , H. Panagopoulos , G. Spanoudes

We describe a procedure to determine moments of parton distribution functions of any order in lattice quantum chromodynamics (QCD). The procedure is based on the gradient flow for fermion and gauge fields. The flowed matrix elements of…

High Energy Physics - Lattice · Physics 2024-10-03 Andrea Shindler

We present the first complete lattice QCD calculation of the four structure-dependent form factors governing the rare charged kaon decay $K^- \to \ell^- \bar{\nu}_\ell \ell'^+ \ell'^-$, with fully controlled statistical and systematic…

High Energy Physics - Lattice · Physics 2026-05-22 R. Di Palma , R. Frezzotti , G. Gagliardi , V. Lubicz , G. Martinelli , C. T. Sachrajda , F. Sanfilippo , S. Simula , N. Tantalo