Related papers: Weak Matrix Elements without Quark Masses on the L…
We calculate basis-space converged neutrinoless $\beta \beta$ decay nuclear matrix elements for the lightest candidates: 48Ca, 76Ge and 82Se. Starting from initial two- and three-nucleon forces, we apply the ab initio in-medium similarity…
Composite dark matter candidates, which can arise from new strongly-coupled sectors, are well-motivated and phenomenologically interesting, particularly in the context of asymmetric generation of the relic density. In this work, we employ…
We present non-perturbative renormalization factors for $\Delta S=2$ four-quark operators in quenched domain-wall QCD using the Schroedinger functional method. Non-perturbative renormalization factor for $B_K$ is evaluated at hadronic…
The complete matrix elements for e^+ e^- -> 4f and e^+ e^- -> 4f + gamma are calculated in the Electroweak Standard Model for polarized massless fermions. The matrix elements for all final states are reduced to a few compact generic…
We investigate the light-quark mass and spatial volume dependence of matrix elements of Delta B = 2 and Delta C = 2 four-fermion operators. These operators are relevant for Neutral B(s) and D mixing in and beyond the Standard Model. An…
We report results of quark masses in quenched lattice QCD with the Kogut-Susskind fermion action, employing the Reguralization Independent scheme (RI) of Martinelli et al. to non-perturbatively evaluate the renormalization factor relating…
We calculate the non-forward quark matrix elements for operators with two covariant derivatives in one-loop lattice perturbation theory using Wilson fermions. These matrix elements are needed in the renormalisation of the second moment of…
We propose a method to non-perturbatively calculate the forward-scattering matrix elements relevant to inclusive semi-leptonic B meson decays. Corresponding hadronic structure functions at unphysical kinematics are accessible through…
We report on an exploratory study of domain wall fermions (DWF) as a lattice regularisation for heavy quarks. Within the framework of quenched QCD with the tree-level improved Symanzik gauge action we identify the DWF parameters which…
We present the results of a partially quenched lattice QCD calculation of light quark masses with $N_f=2$ degenerate dynamical flavors. Numerical simulations are carried out using the plaquette gauge action and the Wilson quark action at…
While neutrino oscillation experiments have demonstrated that neutrinos have small, nonzero masses, much remains unknown about their properties and decay modes. One potential decay mode --- neutrinoless double beta decay ($0 \nu \beta…
Understanding the structure of the fermion mixing matrices is an important question in particle physics. The quark mixing matrix is approximately diagonal while the lepton mixing matrix has large off-diagonal elements. Attempting to…
We compute the renormalisation factors (Z-matrices) of the $\Delta F=2$ four-quark operators needed for Beyond the Standard Model (BSM) kaon mixing. We work with nf=2+1 flavours of Domain-Wall fermions whose chiral-flavour properties are…
We compute non-perturbatively the renormalization constants of composite operators on a quenched $16^3 \times 28 $ lattice with lattice spacing $a$ = 0.20 fm for the overlap fermion by using the regularization independent (RI) scheme. The…
I describe recent work with V. Cirigliano and E. Golowich on the effect of dimension eight operators on weak nonleptonic amplitudes. The basic message is that there is an inconsistency in the way that many calculations are traditionally…
We briefly review and compare three methods (one perturbative, one based on Ward Identities and one non-perturbative) for the calculation of the renormalization constants of lattice operators. The following results are presented: (a) non…
Neutrinoless double-beta ($0\nu\beta\beta$) decays provide an excellent probe for determining whether neutrinos are Dirac or Majorana fermions. The short-range matrix elements associated with the $\pi^- \to \pi^+ ee$ process contribute at…
We calculate for the first time the form factors of the semi-leptonic decays of the $D_s$ meson to $\eta$ and $\eta^\prime$ using lattice techniques. As a by-product of the calculation we obtain the masses and leading distribution…
We present a model-independent calculation of hadron matrix elements for all dimension-six operators associated with baryon number violating processes using lattice QCD. The calculation is performed with the Wilson quark action in the…
We propose a general renormalization method, which avoids completely the use of lattice perturbation theory. We present the results from its numerical applications to two-fermion operators on a $16^3 \times 32$ lattice, at $\beta=6.0$.