Pion-pole term in electroproduction of off-mass-shell pions

1983 ◽  
Vol 28 (1) ◽  
pp. 86-90
Author(s):  
Robert G. Ellis ◽  
Bruce H. J. McKellar
Keyword(s):  
2001 ◽  
Vol 16 (10) ◽  
pp. 1679-1701 ◽  
Author(s):  
B. SATHIAPALAN

We continue the discussion of our previous paper on writing down gauge-invariant interacting equations for a bosonic string using the loop variable approach. In the earlier paper the equations were written down in one higher dimension where the fields are massless. In this paper we describe a procedure for dimensional reduction that gives interacting equations for fields with the same spectrum as in bosonic string theory. We also argue that the on-shell scattering amplitudes implied by these equations for the physical modes are the same as for the bosonic string. We check this explicitly for some of the simpler equations. The gauge transformation of space–time fields induced by gauge transformations of the loop variables are discussed in some detail. The unintegrated (i.e. before the Koba–Nielsen integration), regularized version of the equations, are gauge invariant off-shell (i.e. off the free mass shell).


1977 ◽  
Vol 15 (1) ◽  
pp. 121-128 ◽  
Author(s):  
A. A. Golestaneh
Keyword(s):  

1968 ◽  
Vol 21 (22) ◽  
pp. 1548-1550 ◽  
Author(s):  
Eugene Colton ◽  
Peter Schlein ◽  
Eugene Gellert ◽  
Gerald Smith

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Y. Ünal ◽  
Ulf-G. Meißner

Abstract We report on the calculation of the CP-violating form factor F3 and the corresponding electric dipole moment for charmed baryons in the spin-1/2 sector generated by the QCD θ-term. We work in the framework of covariant baryon chiral perturbation theory within the extended-on-mass-shell renormalization scheme up to next-to-leading order in the chiral expansion.


1992 ◽  
Vol 07 (32) ◽  
pp. 3037-3043 ◽  
Author(s):  
T. GOLDMAN ◽  
J.A. HENDERSON ◽  
A.W. THOMAS

In generating a charge-symmetry breaking potential using ρ-ω mixing it is usually assumed that the mixing amplitude is constant (at the on-mass-shell value). Since the exchanged meson is actually far off-shell one must question the validity of this assumption. By constructing a simple quark model in which the mixing is generated by the u-d quark mass difference, we find that the assumption seems to be a very poor one.


Author(s):  
David Montenegro ◽  
B. M. Pimentel

We examine the generalized quantum electrodynamics as a natural extension of the Maxwell electrodynamics to cure the one-loop divergence. We establish a precise scenario to discuss the underlying features between photon and fermion where the perturbative Maxwell electrodynamics fails. Our quantum model combines stability, unitarity, and gauge invariance as the central properties. To interpret the quantum fluctuations without suffering from the physical conflicts proved by Haag’s theorem, we construct the covariant quantization in the Heisenberg picture instead of the Interaction one. Furthermore, we discuss the absence of anomalous magnetic moment and mass-shell singularity.


1990 ◽  
Vol 05 (17) ◽  
pp. 3391-3399 ◽  
Author(s):  
AMRUTA MISHRA ◽  
H. MISHRA ◽  
S.P. MISRA

We discuss here some nonperturbative techniques of field theory, where we dress nuclear matter as a whole with off-mass-shell pions. Here s-wave pion pairs simulate the effect of σ-meson of the mean field approach of Walecka. The signatures are in agreement with earlier results along with new physical insight.


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