483 research outputs found
One Loop Integrals at Finite Temperature and Density
The technique of decomposing Feynman diagrams at the one loop level into
elementary integrals is generalized to the imaginary time Matsubara formalism.
The three lowest integrals, containing one, two and three fermion lines, are
provided in a form that separates out the real and imaginary parts of these
complex functions, according to the input arguments, in a fashion that is
suitable for numerical evaluation. The forms given can be evaluated for
arbitrary values of temperature, particle mass, particle momenta and chemical
potential.Comment: 32 Pages REVTeX, 9 Figures available as separate fil
Families of particles with different masses in PT-symmetric quantum field theory
An elementary field-theoretic mechanism is proposed that allows one
Lagrangian to describe a family of particles having different masses but
otherwise similar physical properties. The mechanism relies on the observation
that the Dyson-Schwinger equations derived from a Lagrangian can have many
different but equally valid solutions. Nonunique solutions to the
Dyson-Schwinger equations arise when the functional integral for the Green's
functions of the quantum field theory converges in different pairs of Stokes'
wedges in complex field space, and the solutions are physically viable if the
pairs of Stokes' wedges are PT symmetric.Comment: 4 pages, 3 figure
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