Pseudo-scalar meson form factors with maximally twisted Wilson fermions at Nf = 2

Abstract

We present preliminary results for various electroweak form factors of pseudo-scalar mesons using the tree-level improved Symanzik gauge action and the maximally twisted mass fermionic action with Nf = 2 dynamical flavors. Our results, obtained for both light and heavy quark masses at a single lattice spacing (a ~ 0.09 fm) and at a single lattice volume (V * T = 24**3 * 48), exhibit a quite remarkable statistical precision thanks to the use of all-to-all quark propagators computed with a stochastic method. Moreover very low values of the four-momentum transfer are achieved by making use of twisted boundary conditions on the valence quark fields. The mass dependence of the pion charge radius is analyzed using Chiral Perturbation Theory, obtaining clear evidence of relevant two-loop contributions. The universal Isgur-Wise function is computed from heavy-to-heavy electromagnetic transitions and its slope in the case of $u(d)$ spectator quarks is found to be rho(IW)**2 = 0.77 +/- 0.28, where the error is statistical only.

arXiv comment7 pages, 6 figures; proc. of the XXV International Symposium on Lattice Field Theory, July 30 - August 4, 2007, Regensburg, Germany. Revised version with updated Fig. 4 and references

References in corpus (13)

• Determination of the Charged Pion Form Factor at Q2=1.60 and 2.45 (GeV/c)2
• Twisted Boundary Conditions in Lattice Simulations
• Aharonov-Bohm effect and nucleon-nucleon phase shifts on the lattice
• Determination of the pion charge form factor for Q^2=0.60-1.60 GeV^2
• Decay width of light quark hybrid meson from the lattice
• Dynamical Twisted Mass Fermions with Light Quarks
• On the discretization of physical momenta in lattice QCD
• Quark mass dependence of hadron masses from lattice QCD
• Scaling study of the pion electroproduction cross sections and the pion form factor
• Lattice study of semileptonic form factors with twisted boundary conditions
• Lattice QCD with two light Wilson quarks and maximally twisted mass
• Multiple mass solvers
• Light quark masses and pseudoscalar decay constants from Nf=2 twisted mass QCD

Cited by in corpus (8)

• The pion's electromagnetic form factor at small momentum transfer in full lattice QCD
• Use of stochastic sources for the lattice determination of light quark physics
• Kaon physics: a lattice perspective
• Exponential reduction of finite volume effects with twisted boundary conditions
• Progress in hadron structure physics on the lattice
• Progress in kaon physics on the lattice
• Kl3 and pion form factors using partially twisted boundary conditions
• Investigations of hadron structure on the lattice