Search results for "Breit-Wigner"

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Rho resonance, timelike pion form factor, and implications for lattice studies of the hadronic vacuum polarization

2020

We study isospin-1 P-wave ππ scattering in lattice QCD with two flavors of O(a) improved Wilson fermions. For pion masses ranging from mπ=265 MeV to mπ=437 MeV, we determine the energy spectrum in the center-of-mass frame and in three moving frames. We obtain the scattering phase shifts using Lüscher’s finite-volume quantization condition. Fitting the dependence of the phase shifts on the scattering momentum to a Breit-Wigner form allows us to determine the corresponding ρ mass mρ and gρππ coupling. By combining the scattering phase shifts with the decay matrix element of the vector current, we calculate the timelike pion form factor, Fπ, and compare the results to the Gounaris-Sakurai repr…

1 [isospin]Particle physicsdecay constant [rho(770)]High Energy Physics::Latticeclover [fermion]energy spectrumFOS: Physical sciencesWilson [quark]01 natural sciencesphase shiftHigh Energy Physics - LatticePionvector [correlation function]Charge radius0103 physical sciencesmagnetic moment [muon]quantum chromodynamicsmass [rho(770)]hadronic [vacuum polarization]ddc:530Vacuum polarizationflavor: 2 [quark]010306 general physicsnumerical calculationscharge radius [pi]PhysicsMuonAnomalous magnetic dipole moment010308 nuclear & particles physicsScatteringHigh Energy Physics - Lattice (hep-lat)scatteringlattice field theoryLattice QCDFermionBreit-Wignermass dependence [quark]form factor [pi]effect [finite size]vector [current]quantizationPhysical Review D
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