Tue·Sep 11, 2007Tuesday·September 11, 2007

1. 01*

   The K+K+ Scattering Length from Lattice QCD

   Silas Beane🇺🇸 · Thomas Luu🇺🇸 · Kostas Orginos🇺🇸 · Assumpta Parreno🇪🇸 · Martin Savage🇺🇸 · Aaron Torok🇺🇸 · Andre Walker-Loud🇺🇸

   The K+K+ scattering length is calculated in fully-dynamical lattice QCD with domain-wall valence quarks on the MILC asqtad-improved gauge configurations with rooted staggered sea quarks. Three-flavor mixed-action chiral perturbation theory at next-to-leading order, which includes the leading effects of the finite lattice spacing, is used to extrapolate the results of the lattice calculation to the physical value of m_{K+}/f_{K+}. We find m_{K+} a_{K+K+} = -0.352 +- 0.016, where the statistical and systematic errors have been combined in quadrature.

   hep-lathep-phnucl-thPRD(2008)·79 citations
2. 02*

   Exclusive processes in position space and the pion distribution amplitude

   V. Braun🇩🇪 · D. Müller🇩🇪

   We suggest to carry out lattice calculations of current correlators in position space, sandwiched between the vacuum and a hadron state (e.g. pion), in order to access hadronic light-cone distribution amplitudes (DAs). In this way the renormalization problem for composite lattice operators is avoided altogether, and the connection to the DA is done using perturbation theory in the continuum. As an example, the correlation function of two electromagnetic currents is calculated to the next-to-next-to-leading order accuracy in perturbation theory and including the twist-4 corrections. We argue that this strategy is fully competitive with direct lattice measurements of the moments of the DA, defined as matrix elements of local operators, and offers new insight in the space-time picture of hard exclusive reactions.

   ↳ hep-phhep-latEPJC(2008)·242 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.