arXiv subjects

Eduard Masso

Publications and source records attributed to Eduard Masso.

42 records · Page 3Linked to original sources

arXiv1997

Pseudoscalar Conversion and Gamma-Rays from Supernovae

A light pseudoscalar coupled to two photons would be copiously emitted by the core of a supernova and part of this flux would be converted to gamma-rays by the galactic magnetic field. Measurements on the SN1987A gamma-ray flux by the Gamma-Ray Spectrometer on the Solar Maximum Mission satellite imply stringents bounds on such process. The improved generation of satellite-borne detectors, like EGRET or the projegeneration of satellite-borne detectors, like EGRET or the project GLAST, could be able to detect a pseudoscalar-to-photon signal from a nearby supernova.

astro-ph↗

arXiv1997

New Constraints on a Light Spinless Particle Coupled to Photons

We obtain new stringent constraints on a light spinless particle phi coupled only to photons at low energies, considering its effects on the extragalactic photon background, the blackbody spectrum of the CMBR and the cosmological abundance of deuterium.

hep-ph↗

arXiv1996

Improved Bounds on the Electromagnetic Dipole Moments of the Tau Lepton

Using electroweak data and an effective Lagrangian approach we obtain stringent bounds on the tau anomalous magnetic moment, $-0.004 \leq a_τ\leq 0.006$, and on its electric dipole moment, $|d_τ| \leq 1.1 \times 10^{-17} e$ cm. This significantly improves our previous bounds. With the same method, we obtain limits on the dipole moments of other fermions.

hep-ph↗

arXiv1996

Baryonic Dark Matter: Theory and Experiment. Overview

The general arguments for baryonic and galactic dark matter are presented. Limits coming from a variety of theoretical considerations and observations are discussed. The surviving candidates for galactic baryonic dark matter seem most likely to be in the form of compact objects and could be in one of two mass windows: either in the brown dwarf regime or in the mass range corresponding to supermassive black holes. Microlensing towards LMC is probing the first window. It is important to keep in mind that these experiments may detect compact heavy objects, independent of their constituency.

astro-ph↗

arXiv1996

Microlensing Implications for Halo Dark Matter

The most accurate way to get information on the mass of the MACHOs (Massive Astrophysical Compact Halo Objects) is to use the method of mass moments. For the microlensing events detected so far by the EROS and the MACHO collaborations in the Large Magellanic Cloud the average mass turns out to be 0.08$M_{\odot}$. Assuming a spherical standard halo model we find that MACHOs contribute about 20\% to the halo dark matter. The eleven events recorded by OGLE, mainly during its first two years of operation, in the galactic bulge lead to an average mass of 0.29$M_{\odot}$, whereas forty events detected by MACHO during its first year give 0.16$M_{\odot}$, thus suggesting that the lens objects are faint disk stars.

astro-ph↗

arXiv1993

On the Mass of the Dark Compact Halo Objects

Recently the French EROS collaboration and the American-Australian MACHO collaboration have reported the observation of altogether three possible microlensing events by monitoring over several years the brightness of millions of stars in the Large Magellanic Cloud. For each of these events, assuming they are due to microlensing, we compute the most likely mass for the dark compact halo object, which acted as gravitational lens. The most likely masses are 0.12, 0.31 and 0.38 $M_{\odot}$. The average mass calculated using the method of moments turns out to be 0.14 $M_{\odot}$.

astro-ph↗