CP violation in charm decays

Results on CP violation searches in charm decays performed by the LHCb experiment are reviewed. These include an update of the measurement of the difference in time-integrated {\em CP} asymmetry between $D^0\to K^-K^+$ and $D^0\to \pi^-\pi^+$ using $D^0$ from prompt $D^{*+}, a measurement of the same observable using an independent sample of$D^0$from semileptonic B decays, and CP violation searches performed on charged$D$ mesons. All results have been released since FPCP 2012.Comment: Presented at the 2013 Flavor Physics and CP Violation (FPCP-2013), Buzios, Rio de Janeiro, Brazil, May 19-24 2013, 13 pages, 5 figure

High frequency magnetic behavior through the magnetoimpedance effect in CoFeB/(Ta, Ag, Cu) multilayered ferromagnetic thin films

We studied the dynamics of magnetization through an investigation of the magnetoimpedance effect in CoFeB/(Ta, Ag, Cu) multilayered thin films grown by magnetron sputtering. Impedance measurements were analyzed in terms of the mechanisms responsible for their variations at different frequency intervals and the magnetic and structural properties of the multilayers. Analysis of the mechanisms responsible for magnetoimpedance according to frequency and external magnetic field showed that for the CoFeB/Cu multilayer, ferromagnetic resonance (FMR) contributes significantly to the magnetoimpedance effect at frequencies close to 470 MHz. This frequency is low when compared to the results obtained for CoFeB/Ta and CoFeB/Ag multilayers and is a result of the anisotropy distribution and non-formation of regular bilayers in this sample. The MImax values occurred at different frequencies according to the used non-magnetic metal. Variations between 25% and 30% were seen for a localized frequency band, as in the case of CoFeB/Ta and CoFeB/Ag, as well as for a wide frequency range, in the case of CoFeB/Cu.Comment: 14 pages, 5 figure