5,545 research outputs found
COUPLING CHIRAL BOSONS TO GRAVITY
The chiral boson actions of Floreanini and Jackiw (FJ), and of McClain,Wu and
Yu (MWY) have been recently shown to be different representations of the same
chiral boson theory. MWY displays manifest covariance and also a (gauge)
symmetry that is hidden in the FJ side, which, on the other hand, displays the
physical spectrum in a simple manner. We make use of the covariance of the MWY
representation for the chiral boson to couple it to background gravity showing
explicitly the equivalence with the previous results for the FJ representationComment: 8 pages, Latex, no figure
Superspace Formulation for the BRST Quantization of the Chiral Schwinger Model
It has recently been shown that the Field Antifield quantization of anomalous
irreducible gauge theories with closed algebra can be represented in a BRST
superspace where the quantum action at one loop order, including the Wess
Zumino term, and the anomalies show up as components of the same superfield. We
show here how the Chiral Schwinger model can be represented in this
formulation.Comment: 11 pages, Late
Towards Relativistic Skyrmions
We revisit baryons in the Skyrme model. Starting from static baryons in the
helicity eigenstates, we generalize their wavefunctions to the non-static and
relativistic regime. A new representation for gamma matrices in the soliton
collective space is constructed and the corresponding Dirac equation is
obtained. As an example, we draw consideration on how to apply this new
representation on the calculus of vector current vacuum expectation values for
baryon states of spin and isospin half and arbitrary momenta and we show how
elastic form factors can be derived.Comment: 7 pages, 7th Conference Mathematical Methods in Physics - Londrina
2012, Rio de Janeiro, Brazi
Axial Anomaly from the BPHZ regularized BV master equation
A BPHZ renormalized form for the master equation of the field antifiled (or
BV) quantization has recently been proposed by De Jonghe, Paris and Troost.
This framework was shown to be very powerful in calculating gauge anomalies. We
show here that this equation can also be applied in order to calculate a global
anomaly (anomalous divergence of a classically conserved Noether current),
considering the case of QED. This way, the fundamental result about the
anomalous contribution to the Axial Ward identity in standard QED (where there
is no gauge anomaly) is reproduced in this BPHZ regularized BV framework.Comment: 10 pages, Latex, minor changes in the reference
Generalized baryon form factors and proton structure functions in the Sakai-Sugimoto model
We investigate the production of positive parity baryon resonances in proton
electromagnetic scattering within the Sakai-Sugimoto model. The latter is a
string model for the non-perturbative regime of large QCD. Using
holographic techniques we calculate the generalized Dirac and Pauli form
factors that describe resonance production. We use these results to estimate
the contribution of resonance production to the proton structure functions.
Interestingly, we find an approximate Callan-Gross relation for the structure
functions in a regime of intermediate values of the Bjorken variable.Comment: v3: 38 pages, 25 figures. We added a new subsection in order to
compare our results with experimental data. To appear in Nucl. Phys.
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