Related papers: Past, Present, and Possible Future Limits on the P…
While quantum mechanics precludes the perfect knowledge of so-called "conjugate" variables, such as time and frequency, we discuss the importance of compromising to retain a fair knowledge of their combined values. In the case of light, we…
I comment on a recent preprint "A Proposal to Measure Photon-Photon Scattering" that appeared recently as arXiv:1106.0465v1 [hep-ph].
This article describes the various experimental bounds on the variation of the fundamental constants of nature. After a discussion on the role of fundamental constants, of their definition and link with metrology, the various constraints on…
This is a critical discussion of physical relevance of some space-time characteristics which are in current use in high energy physics.
I very briefly review both the historical and constructive approaches to relativistic quantum mechanics and relativistic quantum field theory including remarks on the possibility of a non-vanishing photon mass, as well as a foolhardy…
Future lepton colliders will have a rich top quark physics program which would add to our understanding of this interesting quark and promise an ultimate precision on the experimental knowledge of top-quark mass. We present possible…
The structure of the photon is studied in high energy photon-proton interactions at HERA and photon-photon interactions at LEP. The status of these measurements is reviewed.
While the deflection of light is achromatic in General Relativity, it is not always so in several new-physics models (e.g. certain quantum-gravity and string-inspired models, models with nonminimal photon-gravity coupling or with massive…
We present the strongest current cosmological upper limit on the sum of neutrino masses of < 0.18 (95% confidence). It is obtained by adding observations of the large-scale matter power spectrum from the WiggleZ Dark Energy Survey to…
It is shown that due to radiative corrections a photon having a non vanishing component of its momentum perpendicular to it, bears a non-zero magnetic moment. All modes of propagation of the polarization operator in one loop approximation…
We present a short review of experimental and theoretical constraints on the mass of the Standard Model Higgs boson. We briefly illustrate the unsatisfactory aspects of the standard theory, and we present some general considerations about…
An introduction is given to recent results in prompt photon production in different reactions.
Light extra U(1) gauge bosons, so called hidden photons, which reside in a hidden sector have attracted much attention since they are a well motivated feature of many scenarios beyond the Standard Model and furthermore could mediate the…
In this brief review, I discuss the new physics unveiled by neutrino oscillation experiments over the past several years, and discuss several attempts at understanding the mechanism behind neutrino masses and lepton mixing. It is fair to…
A possibility to constrain axion-like particles from precision atomic physics is considered.
A brief review of searches for physics beyond the Standard Model in photonic final states at LEP is given here. These include searches for supersymmetry, large extra dimensions and contact interactions. Recent results from all four LEP…
The Particle Data Group gives an upper bound on the photon mass $m < 2 \times 10^{-16}$eV from a laboratory experiment and lists, but does not adopt, an astronomical bound $m < 3 \times 10^{-27}$eV, both of which are based on the plausible…
We briefly review the limits on new interactions implied by electroweak precision data. Special attention is payed to the bounds on the Higgs boson mass. We also comment on the required cancellation among the new contributions to precisely…
Energy-dependent speeds of light have been considered an observable signature of quantum gravity effects. The two simplest dispersion relationships produce either linear or quadratic corrections, in particle energy, to the photon speed. The…
We try to understand how particles acquire mass in general, and in particular, how they acquire mass in the standard model and beyond.