18,891 research outputs found
Rigid supersymmetry with boundaries
We construct rigidly supersymmetric bulk-plus-boundary actions, both in
-space and in superspace. For each standard supersymmetric bulk action a
minimal supersymmetric bulk-plus-boundary action follows from an extended -
or -term formula. Additional separately supersymmetric boundary actions can
be systematically constructed using co-dimension one multiplets (boundary
superfields). We also discuss the orbit of boundary conditions which follow
from the Euler-Lagrange variational principle.Comment: 28 pages, JHEP clas
QCD Sum Rules and the Determination of Leading Twist Non-Singlet Operator Matrix Elements
We use QCD sum rules to determine directly the leading-twist non-singlet
operator matrix elements based on calculations of three-point correlator
functions in configuration space. We find a different result from that obtained
by integrating the structure functions' expressions obtained by Belyaev and
Ioffe based on calculations of four-point correlators in momentum space. The
origin of this discrepancy remains unclear.Comment: 9 pages, 5 figure
Cumulant Expansion and Monthly Sum Derivative
Cumulant expansion is used to derive accurate closed-form approximation for
Monthly Sum Options in case of constant volatility model. Payoff of Monthly Sum
Option is based on sum of caped (and probably floored) returns. It is
noticed, that can be used as a small parameter in Edgeworth
expansion. First two leading terms of this expansion are calculated here. It is
shown that the suggest closed-form approximation is in a good agreement with
numerical results for typical mode parameters.Comment: 8 pages, 2 figure
Massless Fermions on the Lattice
We consider a nonlocal lattice action for fermions fermion doubling in
lattice theories. It is shown, that it is possible to avoid the fermionic
doubling in the case of free fermions, but this approach does not reproduce
results for the effective action for gauge fields in the continuum theory,
because the high frequency fermion modes have a strong dependence on the gauge
field.Comment: 16 pages, LATEX, 1 Figure (uuencoded PS-file is attached to the end
of the LATEX file
Generalized Density Matrix Revisited: Microscopic Approach to Collective Dynamics in Soft Spherical Nuclei
The generalized density matrix (GDM) method is used to calculate
microscopically the parameters of the collective Hamiltonian. Higher order
anharmonicities are obtained consistently with the lowest order results, the
mean field [Hartree-Fock-Bogoliubov (HFB) equation] and the harmonic potential
[quasiparticle random phase approximation (QRPA)]. The method is applied to
soft spherical nuclei, where the anharmonicities are essential for restoring
the stability of the system, as the harmonic potential becomes small or
negative. The approach is tested in three models of increasing complexity: the
Lipkin model, model with factorizable forces, and the quadrupole plus pairing
model.Comment: submitted to Physical Review C on 08 May, 201
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