In this paper, we present the final results of our experiment on photon-axion oscillations in the presence of a magnetic field, which took place at LULI (Laboratoire pour lUtilisation des Lasers Intenses, Palaiseau, France). Our null measurement allo
wed us to exclude the existence of axions with inverse coupling constant $M>9.times 10^5$ GeV for low axion masses and to improve the preceding BFRT limits by a factor 3 or more for axion masses $1.1 {meV} <m_a<2.6 {meV}$. We also show that our experimental results improve the existing limits on the parameters of a low mass hidden-sector boson usually dubbed paraphoton because of its similarity with the usual photon.
We present a new evaluation of an 87Sr optical lattice clock using spin polarized atoms. The frequency of the 1S0-3P0 clock transition is found to be 429 228 004 229 873.6 Hz with a fractional accuracy of 2.6 10^{-15}, a value that is comparable to t
he frequency difference between the various primary standards throughout the world. This measurement is in excellent agreement with a previous one of similar accuracy.
