8,142 research outputs found
EvoluciĂł de la superfĂcie protegida dels espais Naturals de les Illes PitiĂĽses (Eivissa i Formentera)
A SUSY A4 model for fermion masses and mixings
We study a supersymmetric extension of the Standard Model based on discrete
A4xZ3xZ4 flavor symmetry. We obtain quark mixing angles as well as a realistic
fermion mass spectrum and we predict tribimaximal leptonic mixing by a
spontaneous breaking of A4. The top quark Yukawa interaction is present at the
renormalizable level in the superpotential while all the other Yukawa
interactions arise only at higher orders. We study the Higgs potential and show
that it can potentially solve the so called vacuum alignment problem. The
leading order predictions are not spoiled by subleading corrections.Comment: version accepted in JHEP, Z3xZ2 changed in Z3xZ4, typos in table
corrected, references adde
Heavy-flavour production in Pb-Pb collisions at the LHC, measured with the ALICE detector
We present the first results from the ALICE experiment on the nuclear
modification factors for heavy-flavour hadron production in Pb-Pb collisions at
sqrt{s_NN}=2.76 TeV. Using proton-proton and lead-lead collision samples at
sqrt{s}=7 TeV and sqrt{s_NN}=2.76 TeV, respectively, nuclear modification
factors R_AA(pt) were measured for D mesons at central rapidity (via displaced
decay vertex reconstruction), and for electrons and muons, at central and
forward rapidity, respectively.Comment: 8 pages, 5 figures, plenary talk at Quark Matter 2011, Annecy, Franc
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