Related papers: The Staggered Eta-prime with Smeared Operators
Using a continuum approach to the hadron bound-state problem, we calculate $\gamma^\ast \gamma \to \eta, \eta^\prime$ transition form factors on the entire domain of spacelike momenta, for comparison with existing experiments and in…
We present results of investigations aiming to determine the hadronic interaction of eta and eta-prime mesons with nucleons. Inferences are based on comparisons of both the differential cross sections and the close-to-threshold excitation…
We measure the branching fraction for the charmless semi-inclusive process B -> eta' X_s, where the eta' meson has a momentum in the range 2.0 to 2.7 GeV/c in the Upsilon(4S) center-of-mass frame and X_s represents a system comprising a…
Taken by itself, the interference with the etaprime appears to strongly affect the amplitude of the transition eta->3 pi. I point out that this effect is fictitious and also occurs in the mass spectrum of the pseudoscalars. Chiral symmetry…
The use of improved staggered actions (HYP, Asqtad) has been proved to reduce the scaling corrections that affected previous calculations of B_K with unimproved (standard) staggered fermions in the quenched approximation. This improved…
We obtained two analytical constraints on the $\eta$-$\eta^\prime$ mixing parameters by considering two-photon decays of $\eta$ and $\eta^\prime$ [$\eta (\eta^\prime) \ra \gamma \gamma$], and productions of $\eta$ and $\eta^\prime$ in the…
The pseudo-scalar flavor-singlet meson mixes with two gluons. A dimensional argument by Kogut and Susskind shows that this can screen the Goldstone pole of the chiral limit in this channel, if the gluon correlations are infrared enhanced.…
We revisit the extraction of parton-to-eta meson fragmentation functions at next-to-leading order accuracy in QCD in the light of the recent hadroproduction measurements in proton-proton collisions obtained by the PHENIX, LHCb, and ALICE…
We compute the matrix elements of the electromagnetic (EM) operator (\bar{s} F{\mu \nu} \sigma{\mu \nu} d) between kaon and pion states, using lattice QCD with maximally twisted-mass fermions and two flavors of dynamical quarks (Nf = 2).…
In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory. We present results for the chiral condensate and the pseudoscalar decay constant…
The notion of a non-perturbative effect is ambiguous if it requires the subtraction of a perturbative part defined by a diverging series. A common procedure consists in dropping the order of minimal contribution and the higher orders. This…
We predict neutron-proton scattering cross-sections and polarization observables up to next-to-next-to-next-to leading order in a renormalization-group invariant description of the strong nucleon-nucleon interaction. Low-energy constants…
We examine eta prime photoproduction, as a novel tool to study baryon resonances around 2 GeV, of particular interest to the quark shell model, which predicts a number of them. We find important roles of the form factors at the strong…
Results for $f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$, and their ratios are presented. High statistics quenched runs at $\beta=5.7$, $5.85$, $6.0$, and $6.3$, plus a run still in progress at $\beta=6.52$ make possible a preliminary extrapolation…
We report the first measurement of the differential cross section for the process gamma gamma --> eta eta in the kinematic range above the eta eta threshold, 1.096 GeV < W < 3.8 GeV over nearly the entire solid angle range, |cos theta*| <=…
We report the results of a numerical study of staggered overlap fermions, following the construction of Adams which reduces the number of tastes from 4 to 2 without fine-tuning. We study the sensitivity of the operator to the topology of…
Light quark masses are computed for Kogut-Susskind fermions by evaluating non-perturbatively the renormalization factor for bilinear quark operators. Calculations are carried out in the quenched approximation at \beta=6.0, 6.2, and 6.4. For…
The production of eta and eta-prime mesons in elementary nucleon-nucleon collisions has been investigated at the synchrotrons CELSIUS, COSY and SATURNE. The magnitude and energy dependence of the total cross section as well as the…
We review the present understanding of etaprime and eta meson physics and these mesons as a probe of gluon dynamics in low-energy QCD. Recent highlights include the production mechanism of eta and etaprime mesons in proton-nucleon…
We construct a one-dimensional quasicrystal by placing scatterers at positions $\chi_n = \ln(p_n)$, the logarithms of the primes. This map compresses the primes to approximately constant density and yields a Fourier transform that is…