12,052 research outputs found

    Aquaculture in tropical Mexican lakes and dams: achievements and perspectives

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    Mexico, with highly diverse physiography, geology, soils and climate, is a country with a broad mosaic of aquatic ecosystems within 320 watersheds. This paper presents a brief picture of Mexican fresh waters, the distribution of rainfall and the potential for aquaculture. The main fish species and water bodies, dams and lakes, are highlighted. The country faces problems of surface water shortage which requires better management

    Non-standard semileptonic hyperon decays

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    We investigate the discovery potential of semileptonic hyperon decays in terms of searches of new physics at teraelectronvolt scales. These decays are controlled by a small SU(3)SU(3)-flavor breaking parameter that allows for systematic expansions and accurate predictions in terms of a reduced dependence on hadronic form factors. We find that muonic modes are very sensitive to non-standard scalar and tensor contributions and demonstrate that these could provide a powerful synergy with direct searches of new physics at the LHC.Comment: v2. Comparison with direct searches of new physics at the LHC presente

    BB decay anomalies from nonabelian local horizontal symmetry

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    Recent anomalies in B→K(∗)ℓℓB\to K^{(*)}\ell\ell meson decays are consistent with exchange of a heavy Z′Z' vector boson. Here we try to connect such new physics to understanding the origin of flavor, by gauging generation number. Phenomenological and theoretical considerations suggest that the smallest viable flavor symmetry (not including any extra U(1) factors) is chiral SU(3)L×SU(3)R{\rm SU(3)}_L\times{\rm SU(3)}_R, which acts only on generation indices and does not distinguish between quarks and leptons. Spontaneous breaking of the symmetry gives rise to the standard model Yukawa matrices, and masses for the 16 Z′Z'-like gauge bosons, one of which is presumed to be light enough to explain the B→K(∗)ℓℓB\to K^{(*)}\ell\ell anomalies. We perform a bottom-up study of this framework, showing that it is highly constrained by LHC dilepton searches, meson mixing, ZZ decays and CKM unitarity. Similar anomalies are predicted for semileptonic decays of BB to lighter mesons, with excesses in the ee,ττee,\tau\tau channels and deficits in μμ\mu\mu, but no deviation in νν\nu\nu. The lightest Z′Z' mass is ≲6 \lesssim 6\,TeV if the gauge coupling is ≲1\lesssim 1.Comment: 13 pages, 4 figures; v2: minor corrections and improvements, references added; v3: corrected fig.1, published versio

    New Physics in s→uℓ−νˉs\to u\ell^-\bar\nu: Interplay between semileptonic kaon and hyperon decays

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    We review a novel model-independent approach to the analysis of new-physics effects in the s→uℓ−νˉs\to u\ell^-\bar\nu transitions. We apply it to (semi)leptonic kaon decays and study their complementarity with pion and hyperon β\beta decays or with collider searches of new physics.Comment: Contribution to the NA62 Physics Handbook. It summarizes the analysis presented in arXiv:1605.07114 and discusses in more detail the interplay between Kμ3K_{\mu3} and semileptonic hyperon decays as new-physics probe
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