Electric Polarizability of Neutral Hadrons from Dynamical Lattice QCD Ensembles Open Access
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Understanding the structure of hadrons is a longstanding goal of nuclear and particle physics. This dissertation examines electromagnetic structure, specifically the electric polarizability of hadrons, in the framework of lattice QCD. We employ the background field method to extract the polarizabilities by analyzing the change in hadrons' energy in the presence of a constant electric field. In this work we compute the electric polarizability of the neutron, neutral pion, and neutral kaon. Lattice QCD calculations of electric polarizabilities are challenging since these parameters are very sensitive to the quark mass--they diverge when the quark mass vanishes. We present a high-statistics calculation for two different sea quark masses corresponding to pion masses of 227 MeV and 306 MeV. To date, these are the calculations closest to the physical point, in the light quark region where we can connect to chiral perturbation theory. For each mass we compute the polarizability using four different lattice volumes allowing us to perform an infinite volume extrapolation for all three hadrons. Our results for the neutron polarizability have small stochastic uncertainties and agree well with predictions from chiral perturbation theory. For the neutral kaon we conduct a chiral extrapolation to the physical pion mass; we find αK = 0.355(70)×10-4 fm3. This work, though it includes dynamical sea quarks, treats them as electrically neutral.