Related papers: Pseudoscalar singlet physics with staggered fermio…
Progress in the calculation of the electromagnetic properties of baryon excitations in lattice QCD is presenting new challenges in the determination of sea-quark loop contributions to matrix elements. A reliable estimation of the sea-quark…
We present new results from our ongoing study of flavor singlet pseudoscalar mesons in QCD. Our approach is based on (a) performing truncated eigenmode expansions for the hairpin diagram and (b) incorporating the ground state contribution…
In hep-lat/0701018, Creutz claims that the rooting trick used in simulations of staggered fermions to reduce the number of tastes misses key physics whenever the desired theory has an odd number of continuum flavors, and uses this argument…
We investigate the masses and mixing of $\eta$, $\eta'$ mesons in the framework of twisted mass lattice QCD with $N_f=2+1+1$ dynamical quark flavors. For the first time we perform a controlled chiral and continuum extrapolation to obtain…
The key assumption used recently by Feldmann, Kroll and Stich [Phys.Rev. D58, 114006 (1998)] that the decay constants f_\eta, and f_\eta ' of the respective eta and eta ' mesons in the quark flavor basis follow the pattern of strange and…
We measure the masses of the pseudoscalar flavour-singlet meson states in the $Sp(4)$ gauge theory coupled to two Dirac fermions transforming in the fundamental representation and three Dirac fermions in the antisymmetric representation.…
In confining lattice gauge theories in which part of the flavor group is coupled weakly to additional gauge fields, both the dynamics of the weak gauge fields as well as lattice artifacts may have non-trivial effects on the orientation of…
Staggered fermion shift symmetries correspond to translations of the fermion field within the unit cell of a hypercubic lattice. They satisfy an algebra and in four Euclidean dimensions can be related to a discrete subgroup of an $SU(4)$…
We study the flavor structure of the lepton and baryon number--conserving dimension-6 operators in the Standard Model effective field theory (SMEFT). Building on the work of [1], we define several well-motivated flavor symmetries and…
Although taste violations significantly affect the results of staggered calculations of pseudoscalar and heavy-light mesonic quantities, those entering staggered calculations of baryonic quantities have not been quantified. Here I develop…
This work continues our program of lattice-QCD baryon physics using staggered fermions for both the sea and valence quarks. We present a proof-of-concept study that demonstrates, for the first time, how to calculate baryon matrix elements…
We extend our lagrangian technique for chiral perturbation theory for quenched QCD to include theories in which only some of the quarks are quenched. We discuss the relationship between the partially quenched theory and a theory in which…
We study the flavour singlet mesons from first principles using lattice QCD. We explore the splitting between flavour singlet and non-singlet for vector and axial mesons as well as the more commonly studied cases of the scalar and…
We explore flavor singlet pseudoscalar meson, eta', spectrum in two-flavor (Nf=2) lattice QCD. The continuum-like relation between the topology of the QCD vacuum and the U(1)_A anomaly, that prevents eta' meson from being a would-be…
This dissertation investigates the flavor mixing effects in supersymmetric models on electroweak precision observables, Higgs boson mass predictions, B-physics observables, quark flavor violating Higgs decays, lepton flavor violating…
One of the most serious problems of the staggered fermion lattice action is flavor symmetry violation. Smeared link staggered fermions can improve flavor symmetry by an order of magnitude relative to the standard thin link action. Over the…
We study the flavour singlet pseudoscalar mesons from first principles using lattice QCD. With N_f=2 flavours of light quark, this is the so-called eta_2 meson and we discuss the phenomenological status of this. Using maximally twisted-mass…
We discuss in detail the extraction of hadronic mixing strengths from lattice studies. We apply this to the mixing of a scalar glueball and a scalar meson in the quenched approximation. We also measure correlations appropriate for…
Quark and lepton flavor physics presents us with a basic question: Can we understand the pattern of masses and mixings of the known quarks and leptons, and how do present and proposed measurements help to advance that goal? Topics discussed…
We present further tests and applications of the new eta-eta' mixing scheme recently proposed by us. The particle states are decomposed into orthonormal basis vectors in a light-cone Fock representation. Because of flavor symmetry breaking…