B_s -> phi rho^0 and B_s -> phi pi^0 as a handle on isospin-violating New Physics

The 2.5 sigma discrepancy between theory and experiment observed in the difference A_CP(B^- --> pi^0 K^-)-A_CP(Bbar^0 --> pi^+ K^-) can be explained by a new electroweak penguin amplitude. Motivated by this result, we analyse the purely isospin-violating decays B_s --> phi rho^0 and B_s --> phi pi^0, which are dominated by electroweak penguins, and show that in presence of a new electroweak penguin amplitude their branching ratio can be enhanced by up to an order of magnitude, without violating any constraints from other hadronic B decays. This makes them very interesting modes for LHCb and future B factories. We perform both a model-independent analysis and a study within realistic New Physics models such as a modified-Z^0-penguin scenario, a model with an additional Z' boson and the MSSM. In the latter cases the new amplitude can be correlated with other flavour phenomena, such as semileptonic B decays and B_s-Bbar_s mixing, which impose stringent constraints on the enhancement of the two B_s decays. In particular we find that, contrary to claims in the literature, electroweak penguins in the MSSM can reduce the discrepancy in the B --> pi K modes only marginally. As byproducts we update the SM predictions to Br(Bbar_s --> phi pi^0)=1.6^{+1.1}_{-0.3}*10^{-7} and Br(Bbar_s --> phi rho^0)=4.4^{+2.7}_{-0.7}*10^{-7} and perform a state-of-the-art analysis of B --> pi K amplitudes in QCD factorisation.Comment: 56 pages, 12 figures, Journal version. Some typos corrected and references added; improved treatment of the MSSM analysis including chirally enhanced corrections. Conclusion unchange

Neurobiology of the control of sleep

Abstract: Individuals have biological rhythms that are coordinated for optimal functioning. The cycle of sleep and wakefulness is regulated by two main processes: the circadian regulation (process C) and the homeostatic regulation (process S). Sleep stages are regulated by ultradian cycles. Recent research has brought light to neurochemical and molecular interactions and complex organization of the networks involved in the timing of sleep and wakefulness. In this chapter we will give an overview of these processes and how they interact to synchronize sleep-wake cycles