Chiral perturbation theory and baryon properties

We derive the scattering amplitude for Goldstone bosons of chiral symmetry off the pseudoscalar charmed mesons up to leading one-loop order in a covariant chiral effective field theory, using the so-called extended-on-mass-shell renormalization scheme. Then we use unitarized chiral perturbation theory to fit to the available lattice data of the S-wave scattering lengths. The lattice data are well described. However, most of the low-energy constants determined from the fit bear large uncertainties. Lattice simulations in more channels are necessary to pin down these values which can then be used to make predictions in other processes related by chiral and heavy quark symmetries.

Section: Jhep11(2015)058mentioning

confidence: 99%

One-loop analysis of the interactions between charmed mesons and Goldstone bosons

Yao

Guo

et al. 2015

“…We use 3 Note, however, that despite this theorem the light quark mass difference mu = m d can modify f+(0)…”

Section: Chiral Extrapolationmentioning

confidence: 99%

“…Indeed it allows to calculate low-energy QCD processes in terms of the light pseudoscalar mesons masses. Hadron properties are presently actively studied on the lattice and chiral extrapolations to their physical values are performed, see for example [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Chiral extrapolation of the strangeness changing scalar Kπ form factor

Bernard

Passemar

2010

We perform a chiral extrapolation of lattice data on the scalar Kπ form factor and the ratio of the kaon and pion decay constants within Chiral Perturbation Theory to two loops. We determine the value of the scalar form factor at zero momentum transfer, at the Callan-Treiman point and at its soft kaon analog as well as its slope. Results are in good agreement with their determination from experiment using the standard couplings of quarks to the W boson. The slope is however rather large. A study of the convergence of the chiral expansion is also performed.

“…This effect would be related to a large violation of the Zweig rule in the scalar sector, indicated by values of the O(p 4 ) LECs L 4 and L 6 significantly different from specific ("critical") values [29][30][31] (see also refs. [32][33][34] for reviews of the subject and a discussion of the baryon sector).…”

Section: Introductionmentioning

confidence: 99%

Chiral dynamics with strange quarks in the light of recent lattice simulations

Bernard

Descotes-Genon

Toucas

2011

Several lattice collaborations performing simulations with 2+1 light dynamical quarks have experienced difficulties in fitting their data with standard N f = 3 chiral expansions at next-to-leading order, yielding low values of the quark condensate and/or the decay constant in the N f = 3 chiral limit. A reordering of these expansions seems required to analyse these data in a consistent way. We discuss such a reordering, known as Resummed Chiral Perturbation Theory, in the case of pseudoscalar masses and decay constants, pion and kaon electromagnetic form factors and K ℓ3 form factors. We show that it provides a good fit of the recent results of two lattice collaborations (PACS-CS and RBC/UKQCD). We describe the emerging picture for the pattern of chiral symmetry breaking, marked by a strong dependence of the observables on the strange quark mass and thus a significant difference between chiral symmetry breaking in the N f = 2 and N f = 3 chiral limits. We discuss the consequences for the ratio of decay constants F K /F π and the K ℓ3 form factor at vanishing momentum transfer.