21,503 research outputs found
Towards establishing Lepton Flavour Universality violation in decays
Rare semileptonic transitions provide some of the
most promising frameworks to search for new physics effects. Recent analyses of
these decays have indicated an anomalous behaviour in measurements of angular
distributions of the decay and
lepton-flavour-universality observables. Unambiguously establishing if these
deviations have a common nature is of paramount importance in order to
understand the observed pattern. We propose a novel approach to independently
and complementary probe this hypothesis by performing a simultaneous amplitude
analysis of and decays. This method enables the direct determination of
observables that encode potential non-equal couplings of muons and electrons,
and are found to be insensitive to nonperturbative QCD effects. If current
hints of new physics are confirmed, our approach could allow an early discovery
of physics beyond the standard model with LHCb run II data sets.Comment: 6 pages, 7 figures. Matching the journal versio
Inverse problems for Jacobi operators II: Mass perturbations of semi-infinite mass-spring systems
We consider an inverse spectral problem for infinite linear mass-spring
systems with different configurations obtained by changing the first mass. We
give results on the reconstruction of the system from the spectra of two
configurations. Necessary and sufficient conditions for two real sequences to
be the spectra of two modified systems are provided.Comment: 25 pages, 2 figures. Typos were corrected, two remarks were added,
material added to Sec.
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