2,078,778 research outputs found
Fractional instantons and bions in the principal chiral model on with twisted boundary conditions
Bions are multiple fractional instanton configurations with zero instanton
charge playing important roles in quantum field theories on a compactified
space with a twisted boundary condition. We classify fractional instantons and
bions in the principal chiral model on with
twisted boundary conditions. We find that fractional instantons are global
vortices wrapping around with their moduli twisted along ,
that carry instanton (baryon) numbers for the symmetric
twisted boundary condition and irrational instanton numbers for generic
boundary condition. We work out neutral and charged bions for the case
with the symmetric twisted boundary condition. We also find for
generic boundary conditions that only the simplest neutral bions have zero
instanton charges but instanton charges are not canceled out for charged bions.
A correspondence between fractional instantons and bions in the
principal chiral model and those in Yang-Mills theory is given through a
non-Abelian Josephson junction.Comment: 30 pages, 2 figures. v2: published version. arXiv admin note: text
overlap with arXiv:1412.768
Merging of transport theory with TDHF: multinucleon transfer in U+U collisions
Multinucleon transfer mechanism in the collision of
system is investigated at MeV in the framework of the quantal diffusion description based on the
stochastic mean-field approach (SMF). Double cross-sections as a
function of the neutron and proton numbers, the cross-sections and
as a function of the atomic numbers and the mass numbers are
calculated for production of the primary fragments. The calculation indicates
the system may be located at an unstable
equilibrium state at the potential energy surface with a slightly negative
curvature along the beta stability line on the plane. This behavior may
lead to rather large diffusion along the beta stability direction.Comment: 10 pages, 10 figures. arXiv admin note: text overlap with
arXiv:1904.0961
Quantized topological terms in weak-coupling gauge theories with symmetry and their connection to symmetry enriched topological phases
We study the quantized topological terms in a weak-coupling gauge theory with
gauge group and a global symmetry in space-time dimensions. We
show that the quantized topological terms are classified by a pair ,
where is an extension of by and an element in group
cohomology \cH^d(G,\R/\Z). When and/or when is finite, the
weak-coupling gauge theories with quantized topological terms describe gapped
symmetry enriched topological (SET) phases (i.e. gapped long-range entangled
phases with symmetry). Thus, those SET phases are classified by
\cH^d(G,\R/\Z), where . We also apply our theory to a simple case
, which leads to 12 different SET phases in 2+1D, where
quasiparticles have different patterns of fractional quantum numbers
and fractional statistics. If the weak-coupling gauge theories are gapless,
then the different quantized topological terms may describe different gapless
phases of the gauge theories with a symmetry , which may lead to different
fractionalizations of quantum numbers and different fractional statistics
(if in 2+1D).Comment: 13 pages, 2 figures, PRB accepted version with added clarification on
obtaining G_s charge for a given PSG with non-trivial topological terms.
arXiv admin note: text overlap with arXiv:1301.767
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