We derive a bound on the magnetic dipole moment of the top quark in the context of the effective Lagrangian approach by using the ratios Rb=Γb/Γh, Rl=Γh/Γl and the Z width. We take into account the vertex and oblique corrections. We obtain the allowed region for the magnetic dipole moment of top quark as -2.94

From the Sloan Digital Sky Survey (SDSS) Data Release 12, which covers the full Baryonic Oscillation Spectroscopic Survey (BOSS) footprint, we investigate the possible variation of the fine-structure constant over cosmological time-scales. We analyse the largest quasar sample considered so far in the literature, which contains 13 175 spectra (10

Several authors have reported that the dynamical masses of massive compact galaxies (M* ≳ 1011 M⊙, re ∼ 1 kpc), computed as Mdyn = 5.0 σe2 re/G, are lower than their stellar masses M*. In a previous study from our group, the discrepancy is interpreted as a breakdown of the assumption of homology that underlie the Mdyn determinations. Here, we

We probe the merging channel of massive galaxies over the z = 0.3-1.3 redshift window by studying close pairs in a sample of 238 galaxies with stellar mass ≳1011 M⊙, from the SHARDS (Survey for High-z Absorption Red and Dead Sources) survey. SHARDS provides medium-band photometry equivalent to low-resolution optical spectra (R ˜ 50), allowing us to

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The study of cool atmospheres is currently a fruitful field of interaction between theorists developing better atmosphere models and observers discovering new cool objects and analysing their emission spectrum. Save for a few close binaries with known parallax and a dynamical mass determination, comparison of spectra to models is the only method