English
Related papers

Related papers: Toolkit for staggered $\Delta S=2$ matrix elements

200 papers

We present results for the matrix elements of the additional $\Delta S=2$ operators that appear in models of physics beyond the Standard Model (BSM), expressed in terms of four BSM $B$-parameters. Combined with experimental results for…

We present results for one-loop matching coefficients between continuum four-fermion operators, defined in the Naive Dimensional Regularization scheme, and staggered fermion operators of various types. We calculate diagrams involving gluon…

High Energy Physics - Lattice · Physics 2011-07-19 Stephen Sharpe , Apoorva Patel

We present results for matrix elements of $\Delta S=2$ four-fermion operators arising generically in models of new physics. These are needed to constrain such models using the measured values of $\varepsilon_K$ and $\Delta M_K$. We use…

We investigate the use of two kinds of staggered fermion operators, smeared and unsmeared. The smeared operators extend over a $4^4$ hypercube, and tend to have smaller perturbative corrections than the corresponding unsmeared operators. We…

High Energy Physics - Lattice · Physics 2009-10-30 Greg Kilcup , Rajan Gupta , Stephen Sharpe

We present a chronological review of the progress in calculating weak matrix elements using staggered fermions. We review the perturbative calculation of one-loop matching formula including both current-current diagrams and penguin diagrams…

High Energy Physics - Lattice · Physics 2009-11-10 Weonjong Lee

Using staggered fermions, we calculate the perturbative corrections to the bilinear and four-fermion operators that are used in the numerical study of weak matrix elements for $\epsilon'/\epsilon$. We present results for one-loop matching…

High Energy Physics - Lattice · Physics 2014-11-17 Weonjong Lee

We calculate the kaon mixing B-parameters for operators arising generically in theories of physics beyond the standard model. We use HYP-smeared improved staggered fermions on the $N_f = 2+1$ MILC asqtad lattices. Operator matching is done…

We present a calculation of the matrix elements of the most general set of DeltaS=2 dimension-six four-fermion operators. The values of the matrix elements are given in terms of the corresponding B-parameters. Our results can be used in…

High Energy Physics - Lattice · Physics 2009-10-31 C. R. Allton , L. Conti , A. Donini , V. Gimenez , L. Giusti , G. Martinelli , M. Talevi , A. Vladikas

We presents results for the matrix elements of a variety of four-fermion operators calculated using quenched Wilson fermions. Our simulations are done on 170 lattices of size $32^3 x 64$ at $\beta = 6.0$. We find $B_K=0.74 +- 0.04 +- 0.05$,…

High Energy Physics - Lattice · Physics 2008-02-03 Rajan Gupta , Tanmoy Bhattacharya , Stephen Sharpe

We compute O(alpha_s) lattice-to-continuum perturbative matching coefficients for the Delta S=2 flavor changing four-quark operators for the Asqtad improved staggered action. In conjunction with lattice simulations with three flavors of…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas Becher , Elvira Gamiz , Kirill Melnikov

We present preliminary results of weak matrix elements relevant to CP violation calculated using the HYP (II) staggered fermions. Since the complete set of matching coefficients at the one-loop level became available recently, we have…

High Energy Physics - Lattice · Physics 2014-11-17 T. Bhattacharya , G. T. Fleming , G. Kilcup , R. Gupta , W. Lee , S. Sharpe

In this work, we find the expressions of continuum HQET four-fermion operators in terms of lattice operators in perturbation theory. To do so, we calculate the one--loop continuum--lattice HQET matching for the complete basis of $\Delta…

High Energy Physics - Lattice · Physics 2009-10-31 V. Gimenez , J. Reyes

We report on a non-perturbative study of the scale-dependent renormalization factors of a multiplicatively renormalizable basis of Delta B=2 parity-odd four-fermion operators in quenched lattice QCD. We also present some preliminary results…

High Energy Physics - Lattice · Physics 2008-11-26 F. Palombi , M. Papinutto , C. Pena , H. Wittig

We calculate one-loop matching factors for bilinear operators composed of improved staggered fermions. We compare the results for different improvement schemes used in the recent literature, all of which involve the use of smeared links.…

High Energy Physics - Lattice · Physics 2009-11-07 Weonjong Lee , Stephen R. Sharpe

We calculate the B-parameters for operators arising in theories of new physics beyond the standard model (BSM) using HYP-smeared improved staggered fermions on the MILC asqtad lattices with N_f = 2+1 flavors. We use three different lattice…

We present results for one-loop matching factors of four-fermion operators composed of HYP-smeared staggered fermions. We generalize previous calculations by using the tree-level improved Symanzik gauge action. These results are needed for…

High Energy Physics - Lattice · Physics 2011-05-19 Jongjeong Kim , Weonjong Lee , Stephen R. Sharpe

We match continuum and lattice heavy-light four-fermion operators at one loop in perturbation theory. For the heavy quarks we use nonrelativistic QCD and for the massless light quarks the highly improved staggered quark action. We include…

High Energy Physics - Lattice · Physics 2014-10-02 Christopher Monahan , Elvira Gamiz , Ron Horgan , Junko Shigemitsu

We calculate the one-loop matching coefficients between continuum and lattice four-fermion operators for lattice operators constructed using staggered fermions and improved by the use of fattened links. In particular, we consider hypercubic…

High Energy Physics - Lattice · Physics 2009-11-10 Weonjong Lee , Stephen Sharpe

We calculate the perturbative corrections to fermion bilinears that are used in numerical simulations when extracting weak matrix elements using staggered fermions. This extends previous calculations of Golterman and Smit, and Daniel and…

High Energy Physics - Lattice · Physics 2014-11-17 Apoorva Patel , Stephen Sharpe

I describe a calculation of B meson mixing at one-loop in staggered chiral perturbation theory, for the complete set of Standard Model and beyond-the-Standard Model operators. The particular lattice representation of the continuum operators…

High Energy Physics - Lattice · Physics 2012-11-02 C. Bernard
‹ Prev 1 2 3 10 Next ›