6533b831fe1ef96bd12990af
RESEARCH PRODUCT
The $I=1$ pion-pion scattering amplitude and timelike pion form factor from $N_{\rm f} = 2+1$ lattice QCD
Colin MorningstarBen HörzJohn BulavaChristian Kronborg Andersensubject
PhysicsQuarkNuclear and High Energy PhysicsParticle physicsIsovector010308 nuclear & particles physicsHigh Energy Physics::LatticeHigh Energy Physics - Lattice (hep-lat)FOS: Physical sciencesLattice QCD01 natural sciencesScattering amplitudeHigh Energy Physics - PhenomenologyLattice constantPionHigh Energy Physics - LatticeHigh Energy Physics - Phenomenology (hep-ph)Dispersion relationLattice (order)0103 physical scienceslcsh:QC770-798lcsh:Nuclear and particle physics. Atomic energy. RadioactivityHigh Energy Physics::Experiment010306 general physicsdescription
The elastic $I=1$ $p$-wave $\pi\pi$ scattering amplitude is calculated together with the isovector timelike pion form factor using lattice QCD with $N_{\rm f}=2+1$ dynamical quark flavors. Wilson clover ensembles generated by the Coordinated Lattice Simulations (CLS) initiative are employed at four lattice spacings down to $a = 0.05\,\mathrm{fm}$, several pion masses down to $m_{\pi} = 200\,\mathrm{MeV}$, and spatial volumes of extent $L = 3.1-5.5\,\mathrm{fm}$. The set of measurements on these ensembles, which is publicly available, enables an investigation of systematic errors due to the finite lattice spacing and spatial volume. The $\pi\pi$ scattering amplitude is fit on each ensemble by a Breit-Wigner resonance lineshape, while the form factor is described better by a thrice-subtracted dispersion relation than the Gounaris-Sakurai parametrization.
year | journal | country | edition | language |
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2019-02-01 |