9,718 research outputs found
On the cancellation of 4-derivative terms in the Volkov-Akulov action
Recently Kuzenko and McCarty observed the cancellation of 4-derivative terms
in the Volkov-Akulov supersymmetric action for the fermionic
Nambu-Goldstone field. Here is presented a simple algebraic proof of the
cancellation based on using the Majorana bispinors and Fiertz identities. The
cancellation shows a difference between the Volkov-Akulov action and the
effective superfield action recently studied by Komargodski and Seiberg and
containing one 4-derivative term. We find out that the cancellation effect
takes place in coupling of the Nambu-Goldstone fermion with the Dirac field.
Equivalence between the KS and the VA Lagrangians is proved up to the first
order in the interaction constant of the NG fermions.Comment: 18 pages; the version accepted for publication in Phys. Rev. D; new
section regarding the proof of the equivalence between the
Komargodski-Seiberg and the Volkov-Akulov actions is added: some comments and
new references are include
Gauging Nonlinear Supersymmetry
Coset methods are used to construct the action describing the dynamics
associated with the spontaneous breaking of the local supersymmetries. The
resulting action is an invariant form of the Einstein-Hilbert action, which in
addition to the gravitational vierbein, also includes a massive gravitino
field. Invariant interactions with matter and gauge fields are also
constructed. The effective Lagrangian describing processes involving the
emission or absorption of a single light gravitino is analyzed.Comment: 20 pages, no figure
Supergravity before and after 1976
This paper is part of the lecture given at the TH Division of CERN and
devoted to the CXXV anniversary of the birthday of Elie Cartan (1869-1951). It
is shown how the methods of differential geometry, due to E. Cartan, were
applied to the construction of the supersymmetry transformation law and to the
actions for Goldstone fermions and supergravity.Comment: 8 pages, latex, CERN-TH.7226/9
Phenomenology of Goldstino Couplings
A general coupling of the Goldstino to the matter field and the weak
gravitational field is constructed based on the standard and the nonlinear
Volkov-Akulov realization of SUSY. The resulting Lagrangian, which is invariant
under SUSY transformations, can give rise to explicit interactions which couple
the helicity +-1/2 states of the gravitino with the gravitational field as well
as the matter field.Comment: 7 pages; final version to appear in Modern Physics Letters
Even and odd symplectic and K\"ahlerian structures on projective superspaces
Supergeneralization of \DC P(N) provided by even and odd K\"ahlerian
structures from Hamiltonian reduction are construct.Operator which
used in Batalin-- Vilkovisky quantization formalism and mechanics which are
bi-Hamiltonian under corresponding even and odd Poisson brackets are
considered.Comment: 19 page
The Tomonaga-Luttinger Model and the Chern-Simons Theory for the Edges of Multi-layer Fractional Quantum Hall Systems
Wen's chiral Tomonaga-Luttinger model for the edge of an m-layer quantum Hall
system of total filling factor nu=m/(pm +- 1) with even p, is derived as a
random-phase approximation of the Chern-Simons theory for these states. The
theory allows for a description of edges both in and out of equilibrium,
including their collective excitation spectrum and the tunneling exponent into
the edge. While the tunneling exponent is insensitive to the details of a
nu=m/(pm + 1) edge, it tends to decrease when a nu=m/(pm - 1) edge is taken out
of equilibrium. The applicability of the theory to fractional quantum Hall
states in a single layer is discussed.Comment: 15 page
Light Gravitinos at Colliders and Implications for Cosmology
Light gravitinos, with mass in the eV to MeV range, are well-motivated in
particle physics, but their status as dark-matter candidates is muddled by
early-Universe uncertainties. We investigate how upcoming data from colliders
may clarify this picture. Light gravitinos are produced primarily in the decays
of the next-to-lightest supersymmetric particle, resulting in spectacular
signals, including di-photons, delayed and non-pointing photons, kinked charged
tracks, and heavy metastable charged particles. We find that the Tevatron with
20/fb and the 7 TeV LHC with 1/fb may both see evidence for hundreds of
light-gravitino events. Remarkably, this collider data is also well suited to
distinguish between currently viable light-gravitino scenarios, with striking
implications for structure formation, inflation, and other early-Universe
cosmology.Comment: 12 pages, 6 figures. To be submitted to Phys. Rev. D
Excited scalar mesons in a chiral quark model
First radial excitations of the isoscalar and isovector scalar mesons
f_0(400-1200), f_0(980) and a_0(980) are investigated in the framework of a
nonlocal version of a chiral quark model of the Nambu--Jona-Lasinio type. It is
shown that f_0(1370), f_J(1710) and a_0(1450) are the first radially excited
states of f_0(400-1200), f_0(980) and a_0(980) which are ground states of the
scalar meson nonet. The mesons' masses and strong decay widths are calculated.
The scalar resonance f_0(1500) is supposed to be a glueball. The status of
K_0^*(1430) is discussed.Comment: LaTeX, 1 figure, minor misprints eradicate
Nonlinear Realizations of Supersymmetry and Other Symmetries
Simultaneous nonlinear realizations of spontaneously broken supersymmetry in
conjunction with other spontaneous and/or explicitly broken symmetries
including R symmetry, global chiral symmetry, dilatations and the
superconformal symmetries is reviewed.Comment: 15 pages, invited brief review for Mod. Phys. Lett.
Pion Polarizability in the NJL model and Possibilities of its Experimental Studies in Coulomb Nuclear Scattering
The charge pion polarizability is calculated in the Nambu-Jona-Lasinio model,
where the quark loops (in the mean field approximation) and the meson loops (in
the approximation) are taken into account. We show that quark loop
contribution dominates, because the meson loops strongly conceal each other.
The sigma-pole contribution plays the main role and
contains strong t-dependence of the effective pion polarizability at the region
. Possibilities of experimental test of this sigma-pole
effect in the reaction of Coulomb Nuclear Scattering are estimated for the
COMPASS experiment.Comment: 11 pages, 8 figure
- …