The fate of the trace anomaly in a finite formulation of field theory

Within the framework of the recently proposed Taylor–Lagrange regularization scheme which leads to finite elementary amplitudes in four-dimensional space–time with no additional dimensionful scales — we show that the trace of the energy–momentum tensor does not show any anomalous contribution even though quantum corrections are considered. Moreover, since the only renormalization we can think of within this scheme is a finite renormalization of the bare parameters to give the physical ones, the canonical dimension of quantum fields is also preserved by the use of this regularization scheme.

Chiral anomaly and strange-nonstrange mixing

As a first step, a simple and pedagogical recall of the η-η′ system is presented, in which the role of the axial anomaly, related to the heterochiral nature of the multiplet of (pseudo)scalar states, is underlined. As a consequence, η is close to the octet and η′ to the singlet configuration. On the contrary, for vector and tensor states, which belong to homochiral multiplets, no anomalous contribution to masses and mixing is present. Then, the isoscalar physical states are to a very good approximation nonstrange and strange, respectively. Finally, for pseudotensor states, which are part of an heterochiral multiplet (just as pseudoscalar ones), a sizable anomalous term is expected: η2(1645) roughly corresponds to the octet and η2(1870) to the singlet.

INTERACTIONS OF A STRING INSPIRED GRAVITON FIELD

We continue to explore the possibility that the graviton in two dimensions is related to a quadratic differential that appears in the anomalous contribution of the gravitational effective action for chiral fermions. A higher dimensional analog of this field might exist as well. We improve the defining action for this diffeomorphism tensor field and establish a principle for how it interacts with other fields and with point particles in any dimension. All interactions are related to the action of the diffeomorphism group. We discuss possible interpretations of this field.

AXIAL ANOMALY FROM THE BPHZ RENORMALIZED BV MASTER EQUATION

We show here that a rigid anomaly (anomalous divergence of a classically conserved Noether current) can also be calculated using the BPHZ renormalized form of the master equation of the field antifield (or BV) quantization. Considering the case of QED (where there is no gauge anomaly), the fundamental result about the anomalous contribution to the axial Ward identity is reproduced in this BPHZ regularized BV framework (originally used to compute gauge anomalies).

SEARCH FOR ANOMALY AT HIGH x IN POLARIZED DEEP INELASTIC SCATTERING DATA

An idea of possible anomalous contribution of nonperturbative origin to the nucleon spin was examined by analyzing data on spin asymmetries in polarized deep inelastic scattering of leptons on nucleons. The region of high Bjorken x was explored. It was shown that experimental data available at present do not exhibit any evidence for this effect.