Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · hep-lat/9211057

Meson Form-factors and Wave-functions with Wilson fermions

R. Gupta·D. Daniel·J. Grandy
View original source ↗Read source document ↗Export metadata ↓

Abstract

Results for semi-leptonic form-factors for processes like $D \to K l ν$ and the Bethe-Salpeter amplitudes (BSA) for pion and rho mesons are presented. The form-factor data is consistent with previous calculations. We find that the long distance fall-off of BSA for both $π$ and $ρ$ is very well fit by an exponential, but surprisingly the effective mass governing this fall-off is lighter than the pion's. Lastly, by studying the dependence of $ρ$ polarization on separation direction we show that there is a measureable $l=2$ state in addition to $l=0$ in the BSA for the rho. (Talk presented by R. Gupta at LATTICE92. Latex needs macro package espcrc2.sty)

Explore related subjects

hep-lat

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R. Gupta, D. Daniel, J. Grandy. 1992-11-24. Meson Form-factors and Wave-functions with Wilson fermions. https://doi.org/10.1016/0920-5632(93)90241-w

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

The sigma meson ($f_0$) at finite temperature with truncated overlap fermions

We study the temperature dependence of meson screening masses in two-flavour lattice QCD using dynamical truncated overlap fermions, a type of lattice chiral fermions. The screening masses for the $π$, $ρ$, $a_1$, $a_0$, and the sigma $(f_0)$ mesons are extracted by computing spatial correlation functions. This exploratory study uses meson screening masses and the connected/disconnected decomposition of the scalar correlator as diagnostic observables to examine how the disconnected contribution changes across the pseudocritical region. Above the pseudocritical temperature $T_{\rm pc}$, the $π$ and $f_0$ screening masses become degenerate, consistent with chiral restoration. The $(ρ,a_1)$ pair also shows the expected degeneracy. Decomposition of the $f_0$ propagator reveals that the connected contribution dominates above $T_{\rm pc}$, while the disconnected part becomes significant below $T_{\rm pc}$, explaining the reduced statistical clarity observed at low $T$. These results demonstrate that dynamical truncated overlap fermion simulations can capture the qualitative thermal behaviour of the scalar sector.

hep-lat↗
arXiv2026

Critical coupling and $Δ\langleϕ^2\rangle$ in three-dimensional $ϕ^4$ theory

We consider the $ϕ^4$ theory with $ϕ(x)\in\mathbb{R}$ in three Euclidean dimensions. For a variety of self-couplings $\hatλ$, the critical (bare) parameter $\hatμ_{0\mathrm{c}}^2(\hatλ)$ is determined where the lattice-regulated system changes from the symmetric phase to the broken phase. Next, we send the box volume to infinity and switch to a universal scheme; this yields $\hatμ_\mathrm{c}^2(\hatλ)$ for each simulated $\hatλ$. Finally, a continuum extrapolation gives $f_\mathrm{c}=\lim_{\hatλ\to0} \hatλ^2/\hatμ_\mathrm{c}^2(\hatλ)$, and we find $f_\mathrm{c} = 18.808(64)_{\mathrm{stat}}(45)_{\mathrm{sys}} = 18.808(78)_{\mathrm{tot}}$. In addition, $Δ\langleϕ^2\rangle_\mathrm{c}/λ= -0.00303(12)_{\mathrm{stat}}(12)_{\mathrm{sys}} = -0.00303(17)_{\mathrm{tot}}$ is determined in the combined continuum and infinite-volume limit.

hep-lat↗
arXiv2026

Looking at radiative corrections to the $Σ^\pm\toΛe^\pm \barν$ semileptonic decay-rate ratio

We investigate the impact of radiative corrections on the ratio of the semileptonic decay rates $Σ^\pm\toΛe^\pm \barν$. Phenomenological analyses point to sizable radiative effects on the experimentally measured ratio. From a theoretical perspective, this observable is particularly appealing because several hadronic and electroweak contributions partially cancel in the ratio, providing a cleaner probe of electromagnetic effects. We identify the dominant contributions to the radiative corrections and develop the framework for a dedicated calculation. This represents a first step toward a precise theoretical description of baryon semileptonic decays, helping to assess their potential as precision tests of the Standard Model.

hep-lat↗