2017/01/31 by Liuming Liu, Simone Bacchio, Liu, L. +25
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.1701.08961
openalex publication_date 2017/01/31 · openalex created_date 2017/02/10 · openalex updated_date 2026/08/01
We present results for the isospin-0 ππ s-wave scattering length calculated in twisted mass lattice QCD. We use three Nf = 2 ensembles with unitary pion mass at its physical value, 240~MeV and 330~MeV respectively. We also use a large set of Nf = 2 + 1 +1 ensembles with unitary pion masses varying in the range of 230~MeV - 510~MeV at three different values of the lattice spacing. A mixed action approach with the Osterwalder-Seiler action in the valence sector is adopted to circumvent the complications arising from isospin symmetry breaking of the twisted mass quark action. Due to the relatively large lattice artefacts in the Nf = 2 + 1 +1 ensembles, we do not present the scattering lengths for these ensembles. Instead, taking the advantage of the many different pion masses of these ensembles, we qualitatively discuss the pion mass dependence of the scattering properties of this channel based on the results from the Nf = 2 + 1 +1 ensembles. The scattering length is computed for the Nf = 2 ensembles and the chiral extrapolation is performed. At the physical pion mass, our result MπaI=00 = 0.198(9)(6) agrees reasonably well with various experimental measurements and theoretical predictions.