arXiv subjects

Martin B. Einhorn

Publications and source records attributed to Martin B. Einhorn.

21 records · Page 2Linked to original sources

arXiv1995

Interacting scalar fields in de Sitter space

We investigate the massless $λϕ^4$ theory in de~Sitter space. It is unnatural to assume a minimally coupled interacting scalar field, since $ξ=0$ is not a fixed point of the renormalization group once interactions are included. In fact, the only case where perturbation theory can be trusted is when the field is non-minimally coupled at the minimum of the effective potential. Thus, in perturbation theory, there is no infrared divergence associated with this scalar field.

gr-qc↗

arXiv1993

On the Hadronic Contribution to Light-by-light Scattering in $g_μ-2$

We comment on the theoretical uncertainties involved in estimating the hadronic effects on the light-by-light scattering contribution to the anomalous magnetic moment of the muon, especially based on the analysis and results of T. Kinoshita, B. Ni\v zić, and Y. Okamoto, Phys.\ Rev.\ D31, 2108 (1985). From the point of view of an effective field theory and chiral perturbation theory, we suggest that the charged pion contribution may be better determined than has been appreciated. However, the neutral pion contribution needs greater theoretical insight before its magnitude can be reliably estimated.

hep-ph↗

arXiv1993

Beyond the Standard Model with Effective Lagrangians

An Effective Lagrangian description is useful for describing potential physics beyond the Standard Model. The method is illustrated by reference to interactions among the electroweak bosons ($W^\pm$ \& $Z^0$). The resulting estimates of the magnitude of these corrections suggest that they would be at best marginally detectable at high energy $e^-e^+$ colliders or hadron colliders. In loop calculations, contrary to lore, such deviations from Standard Model self-couplings never give observable corrections that grow as a power of the scale $Λ$ at which new physics enters, so there are never effects proportional to powers of $Λ/M_W$.

hep-ph↗