![]() ![]() The experimentally measured values of mixing angles are large (for a review see and the references therein), with the exception of, which was constrained for several years by the CHOOZ result and was only recently measured. CLFV in the Standard ModelĪlthough forbidden in the SM, space for CLFV processes can be easily created if one includes neutrino masses and mixing, which are known to be nonvanishing. The experimental searches for CLFV reactions and their impact on the BSM models are the subject of this paper. This indicates that CLFV effects are tiny and very difficult to measure nevertheless, the interest for this search is enormous since when one introduces new particles beyond the SM (as, for instance the supersymmetric partners of the ordinary particles) CLFV processes emerge as one of the distinctive features of Beyond Standard model (from now on BSM) theories. Then, the natural expectation is that CLFV reactions should be observed even in the charged sector, but, despite a long-term experimental effort, no positive result was obtained. However, it is experimentally proved from reactor, accelerator, solar and atmospheric neutrino experiments that the Lepton Flavour Violation does take place in the neutral sector: neutrinos are definitely massive and oscillate between different flavours, while their total number is conserved. Different lepton generations (electron, muon and tau and their neutrinos) are completely decoupled and in all processes allowed in the model the number of members of different generations is separately conserved (Lepton Flavour Conservation). In the minimal Standard model (from now on SM) processes with Lepton Flavour Violation involving charged particles (from now on CLFV) are not allowed at all, since the fermion generations are put in by hand in separate doublets and the neutrinos are assumed to be massless. Limitations due to systematic effects are also discussed in detail together with the solutions being adopted to overcome them. We present currently operating experiments as well as future projects, with emphasis laid on how sensitivity enhancements are accompanied by improvements on detection techniques. In this paper we review past and recent results in this research field, with focus on CLFV channels involving muons and tau's. Therefore, a big experimental effort is currently (and will be for incoming years) accomplished to achieve unprecedented sensitivity on several CLFV processes. As the Standard model background is negligible, the observation of one or more CLFV events would provide incontrovertible evidence for physics beyond Standard model, while a null effect would severely constrain the set of theory parameters. On the other hand, a wide class of Supersymmetric theories, even coupled with Grand Unification models (SUSY-GUT models), predict CLFV processes at a rate within the reach of new experimental searches operated with high resolution detectors at high intensity accelerators. The discussion of data that might decide whether time is one-dimensional (one timeline) or multi-dimensional (branching time) is especially novel.Lepton Flavour Violation in the charged lepton sector (CLFV) is forbidden in the Minimal Standard model and strongly suppressed in extensions of the model to include finite neutrino mixing. It follows in the long philosophical tradition of using dialogue to present philosophical ideas and arguments, but is ground breaking in its use of the dialogue format to introduce readers to the metaphysics of time travel, and is also distinctive in its use of lab results to drive philosophical analysis. A Time Travel Dialogue addresses the possibility of time travel, approaching familiar paradoxes in a rigorous, engaging, and fun manner. Sensible solutions to the main puzzles emerge, ultimately advancing the case for time travel really being possible. She and her two colleagues are pushed by their observations to address the grandfather paradox and other puzzles about backwards causation, with attention also given to causal loops, multi-dimensional time, and the prospect that only the present exists. Rufus’s experimental search for the psi-lepton and the resulting intractable data spurs the discussion on time travel. The setting is the Jefferson National Laboratory during a period of five days in 2010. Rufus, a physics graduate student and a computer scientist this book probes an experimentally supported hypothesis of backwards time travel – and in so doing addresses key metaphysical issues, such as causation, identity over time and free will. Is time travel just a confusing plot device deployed by science fiction authors and Hollywood filmmakers to amaze and amuse? Or might empirical data prompt a scientific hypothesis of time travel? Structured on a fascinating dialogue involving a distinguished physicist, Dr. ![]()
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