21,311 research outputs found
Nuclides as a liquid phase of chiral perturbation theory I: emergence of pion-less SU(2) PT
The Standard Model of particle physics, augmented with neutrino mixing, is at
least very nearly the complete theory of interactions of known particles at
energies accessible to Nature on Earth. Candidate effective theories of nuclear
structure must therefore reflect SM symmetries, especially the chiral global
symmetry of two-massless-quark QCD. For ground-state
nuclei, SU(2) chiral perturbation theory (XPT) enables perturbation in inverse
powers of , with analytic operators renormalized to
all loop orders. We show that pion-less "Static Chiral Nucleon Liquids" (SXNL)
emerge as a liquid phase of SU(2) XPT of protons, neutrons and 3
Nambu-Goldstone boson pions. Far-IR pions decouple from SXNL, simplifying the
derivation of saturated nuclear matter and microscopic liquid drops
(ground-state nuclides). We trace to the global symmetries of
two-massless-quark QCD the power of pion-less SU(2) XPT to capture experimental
ground-state properties of certain nuclides with even parity, spin zero, even
proton number Z, and neutron number N.
We derive the SXNL effective SU(2) XPT Lagrangian, including all order
operators. These include: all 4-nucleon
operators that survive Fierz rearrangement in the non-relativistic limit, and
effective Lorentz-vector iso-vector neutral "-exchange" operators. SXNL
motivate nuclear matter as non-topological solitons at zero pressure: the
Nuclear Liquid Drop Model and Bethe-Weizsacker Semi-Empirical Mass Formula
emerge in an explicit Thomas-Fermi construction provided in the companion
paper. For chosen nuclides, nuclear Density Functional and Skyrme models are
justified to order . We conjecture that inclusion of
higher order operators will result in accurate "natural" Skyrme, No-Core-Shell,
and neutron star models
The Quantum McKay Correspondence for polyhedral singularities
Let G be a polyhedral group, namely a finite subgroup of SO(3). Nakamura's
G-Hilbert scheme provides a preferred Calabi-Yau resolution Y of the polyhedral
singularity C^3/G. The classical McKay correspondence describes the classical
geometry of Y in terms of the representation theory of G. In this paper we
describe the quantum geometry of Y in terms of R, an ADE root system associated
to G. Namely, we give an explicit formula for the Gromov-Witten partition
function of Y as a product over the positive roots of R. In terms of counts of
BPS states (Gopakumar-Vafa invariants), our result can be stated as a
correspondence: each positive root of R corresponds to one half of a genus zero
BPS state. As an application, we use the crepant resolution conjecture to
provide a full prediction for the orbifold Gromov-Witten invariants of [C^3/G].Comment: Introduction rewritten. Issue regarding non-uniqueness of conifold
resolution clarified. Version to appear in Inventione
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