9,543 research outputs found

    On the cancellation of 4-derivative terms in the Volkov-Akulov action

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    Recently Kuzenko and McCarty observed the cancellation of 4-derivative terms in the D=4N=1D=4 {\cal N}=1 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

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    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

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    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

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    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

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    Supergeneralization of \DC P(N) provided by even and odd K\"ahlerian structures from Hamiltonian reduction are construct.Operator Δ \Delta 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

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    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

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    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

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    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

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    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

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    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 1/Nc1/N_c approximation) are taken into account. We show that quark loop contribution dominates, because the meson loops strongly conceal each other. The sigma-pole contribution (mσ2t)1(m^2_\sigma-t)^{-1} plays the main role and contains strong t-dependence of the effective pion polarizability at the region t4Mπ2|t|\geq 4M_\pi^2. 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
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