Current algebra with a four-flavor effective Lagrangian

1978 ◽  
Vol 17 (5) ◽  
pp. 1430-1443 ◽  
Author(s):  
J. Kandaswamy ◽  
J. Schechter ◽  
M. Singer
1986 ◽  
Vol 01 (03) ◽  
pp. 499-544 ◽  
Author(s):  
G.M. SHORE ◽  
G. VENEZIANO

The implications of supersymmetry and chiral Ward identities in supersymmetric gauge theories are explored using current algebra methods, and a critical assessment is made of the relative merits of the current algebra and effective Lagrangian approaches. Using the Ward identities directly, simple derivations are given of several important properties of the condensates in supersymmetric QCD, and of the generalized Dashen formulae. The corrections to these results in the presence of explicit, soft supersymmetry breaking are calculated. A concise formula is presented for the mass splittings within pseudo Goldstone multiplets induced by soft supersymmetry breaking terms. It is shown that if this supersymmetry breaking is the θ=0 component of a chiral superfield, the supertrace of the pseudo Goldstone masses vanishes. Using current algebra reduction formulae, the pseudo Goldstone masses are calculated in supersymmetric Yang-Mills theory, and supersymmetric QCD for NF<NC and NF=NC. Some differences are found between the current algebra and effective Lagrangian predictions, and their possible origins are discussed.


1995 ◽  
Vol 10 (09) ◽  
pp. 1377-1392 ◽  
Author(s):  
GIUSEPPE DEGRASSI ◽  
SERGIO FANCHIOTTI ◽  
PAOLO GAMBINO

The [Formula: see text] correction to the ρ parameter is computed using the current algebra formulation of radiative corrections. This approach is proved to be equivalent to the effective Lagrangian method proposed by Barbieri et al. The same framework is then applied to the calculation of the [Formula: see text] correction to the ratio of neutral-to-charged-current amplitudes in an SU(2) model. In this model the [Formula: see text] contribution is shown to be numerically comparable to the leading [Formula: see text] term for realistic values of the top mass.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
David Osten

Abstract A classical Ed(d)-invariant Hamiltonian formulation of world-volume theories of half-BPS p-branes in type IIb and eleven-dimensional supergravity is proposed, extending known results to d ≤ 6. It consists of a Hamiltonian, characterised by a generalised metric, and a current algebra constructed s.t. it reproduces the Ed(d) generalised Lie derivative. Ed(d)-covariance necessitates the introduction of so-called charges, specifying the type of p-brane and the choice of section. For p > 2, currents of p-branes are generically non- geometric due to the imposition of U-duality, e.g. the M5-currents contain coordinates associated to the M2-momentum.A derivation of the Ed(d)-invariant current algebra from a canonical Poisson structure is in general not possible. At most, one can derive a current algebra associated to para-Hermitian exceptional geometry.The membrane in the SL(5)-theory is studied in detail. It is shown that in a generalised frame the current algebra is twisted by the generalised fluxes. As a consistency check, the double dimensional reduction from membranes in M-theory to strings in type IIa string theory is performed. Many features generalise to p-branes in SL(p + 3) generalised geometries that form building blocks for the Ed(d)-invariant currents.


2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Anthony Ashmore ◽  
Sebastian Dumitru ◽  
Burt A. Ovrut

Abstract The strongly coupled heterotic M-theory vacuum for both the observable and hidden sectors of the B − L MSSM theory is reviewed, including a discussion of the “bundle” constraints that both the observable sector SU(4) vector bundle and the hidden sector bundle induced from a single line bundle must satisfy. Gaugino condensation is then introduced within this context, and the hidden sector bundles that exhibit gaugino condensation are presented. The condensation scale is computed, singling out one line bundle whose associated condensation scale is low enough to be compatible with the energy scales available at the LHC. The corresponding region of Kähler moduli space where all bundle constraints are satisfied is presented. The generic form of the moduli dependent F-terms due to a gaugino superpotential — which spontaneously break N = 1 supersymmetry in this sector — is presented and then given explicitly for the unique line bundle associated with the low condensation scale. The moduli-dependent coefficients for each of the gaugino and scalar field soft supersymmetry breaking terms are computed leading to a low-energy effective Lagrangian for the observable sector matter fields. We then show that at a large number of points in Kähler moduli space that satisfy all “bundle” constraints, these coefficients are initial conditions for the renormalization group equations which, at low energy, lead to completely realistic physics satisfying all phenomenological constraints. Finally, we show that a substantial number of these initial points also satisfy a final constraint arising from the quadratic Higgs-Higgs conjugate soft supersymmetry breaking term.


2021 ◽  
Vol 103 (5) ◽  
Author(s):  
Masaru Hongo ◽  
Suro Kim ◽  
Toshifumi Noumi ◽  
Atsuhisa Ota

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Neng-Chang Wei ◽  
Yu Zhang ◽  
Fei Huang ◽  
De-Min Li

2000 ◽  
Vol 15 (30) ◽  
pp. 4857-4870 ◽  
Author(s):  
D. C. CABRA ◽  
E. FRADKIN ◽  
G. L. ROSSINI ◽  
F. A. SCHAPOSNIK

We propose an effective Lagrangian for the low energy theory of the Pfaffian states of the fractional quantum Hall effect in the bulk in terms of non-Abelian Chern–Simons (CS) actions. Our approach exploits the connection between the topological Chern–Simons theory and chiral conformal field theories. This construction can be used to describe a large class of non-Abelian FQH states.


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