Francesco Brivio

Aql X-1 is the most prolific low-mass X-ray binary transient hosting a neutron star. In this paper we focus on the return to quiescence following the 2010 outburst of the source. This decay was monitored thanks to 11 pointed observations taken with XMM–Newton, Chandra and Swift. The decay from outburst to quiescence is very fast, with an exponential decay characteristic time-scale of ∼2 d. Once in quiescence the X-ray flux of Aql X-1 remained constant, with no further signs of variability or decay. The comparison with the only other well-monitored outburst from Aql X-1 (1997) is tale-telling. The luminosities at which the fast decay starts are fully compatible for the two outbursts, hinting at a mechanism intrinsic to the system and possibly related to the neutron star rotation and magnetic field (i.e. the propeller effect). In addition, for both outbursts, the decay profiles are also very similar, likely resulting from the shut-off of the accretion process on to the neutron star surface. Finally, the quiescent neutron star temperatures at the end of the outbursts are well consistent with one another, suggesting a hot neutron star core dominating the thermal balance. Small differences in the quiescent X-ray luminosity among the two outbursts can be attributed to a different level of the power-law component.

In this presentation I will report on the search for the heavy boson H decaying to a pair of 125 GeV SM-like Higgs bosonsh using the final state of two leptons and twob-jets and the search for a heavy boson A decaying to a SM-like Higgs boson h and a Z boson using the final state of two leptons and two leptons‘‘ (ee or ). The mass range considered in the analysis extends frommA=H ’ 250 GeV up to mA=H ’ 350 GeV. The analysis is performed on a dataset corresponding to an integrated luminosity L = 19:7 fb 1 of proton-proton collision data collected in 2012 by the CMS experiment at p s = 8 TeV.