Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dispersion of Magnetic Excitations in Superconducting Optimally Doped
  YBa_2Cu_3O_6.95   Detailed neutron scattering measurements of YBa_2Cu_3O_6.95 found that the
resonance peak and incommensurate magnetic scattering induced by
superconductivity represent the same physical phenomenon: two dispersive
branches that converge near 41 meV and the in-plane wave-vector q_af=(pi/a,
pi/a) to form the resonance peak. One branch has a circular symmetry around
q_af and quadratic downward dispersion from ~41 meV to the spin gap of
33+-1meV. The other, of lower intensity, disperses from ~41 meV to at least 55
meV. Our results exclude a quartet of vertical incommensurate rods in q-w space
expected from spin waves produced by dynamical charge stripes as an origin of
the observed incommensurate scattering in optimally-doped YBCO.

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The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-th
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: nlin