Hadronic form factors in Lattice QCD at small and vanishing momentum transfer

Abstract

The introduction of partially twisted boundary conditions allows weak and electromagnetic form factors to be evaluated at specified values of the hadronic momenta (and hence momentum transfers) in lattice simulations. We present and demonstrate this technique for the computation of the K->pi semileptonic form factor at zero momentum transfer and for the electromagnetic form factor of the pion at arbitrarily small momentum transfers. These exploratory computations are carried out in full QCD with 3 flavours of sea quarks, but with only two values of m_u=m_d which limits our ability to perform the chiral extrapolations. The results should therefore be viewed primarily as a demonstration of the feasibility of the method. For the K-> pi form factor we compare the new technique to the conventional approach and for the pion form factor we assess our results for very small momentum transfer with the help of chiral perturbation theory.

19 pages, 6 figures

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Cited by in corpus (19)

• FLAG Review 2021
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• Continuum Limit of $B_K$ from 2+1 Flavor Domain Wall QCD
• The pion's electromagnetic form factor at small momentum transfer in full lattice QCD
• FLAG Review 2024
• First lattice calculation of radiative leptonic decay rates of pseudoscalar mesons
• Use of stochastic sources for the lattice determination of light quark physics
• K->pi form factors with reduced model dependence
• SU(2) chiral perturbation theory for Kl3 decay amplitudes
• The kaon semileptonic form factor in Nf=2+1 domain wall lattice QCD with physical light quark masses
• Virtual Photon Emission in Leptonic Decays of Charged Pseudoscalar Mesons
• Finite Volume Effects on the Extraction of Form Factors at Zero Momentum
• Feynman--Hellmann approach to transition matrix elements and quasi-degenerate energy states
• Semileptonic D-decays and Lattice QCD
• Progress in kaon physics on the lattice
• High precision applications of lattice gauge theories in the quest for new physics
• Formal Developments for Lattice QCD with Applications to Hadronic Systems
• Kaon semi-leptonic form factor in lattice QCD