253,221 research outputs found

    epsilon'/epsilon in the Standard Model

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    In order to provide an estimate of eps'/eps several effective theories and physical effects have to be disentangled. In this talk I discuss how it is possible to predict eps '/eps taking into account all sources of large logs. The numerical result one obtains, \eps '/\eps \sim (1.7\pm 0.6) \cdot 10^{-4}, is in good agreement with present measurements.Comment: Talk presented at QCD2000, Montpellier july 200

    Decay of Quasi-Particle in a Quantum Dot: the role of Energy Resolution

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    The disintegration of quasiparticle in a quantum dot due to the electron interaction is considered. It was predicted recently that above the energy \eps^{*} = \Delta(g/\ln g)^{1/2} each one particle peak in the spectrum is split into many components (Δ\Delta and gg are the one particle level spacing and conductance). We show that the observed value of \eps^{*} should depend on the experimental resolution \delta \eps. In the broad region of variation of \delta \eps the lng\ln g should be replaced by \ln(\Delta/ g\delta \eps). We also give the arguments against the delocalization transition in the Fock space. Most likely the number of satellite peaks grows continuously with energy, being 1\sim 1 at \eps \sim \eps^{*}, but remains finite at \eps > \eps^{*}. The predicted logarithmic distribution of inter-peak spacings may be used for experimental confirmation of the below-Golden-Rule decay.Comment: 5 pages, REVTEX, 2 eps figures, version accepted for publication in Phys. Rev. Let

    ELFE : an Electron Laboratory for Europe

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    This paper presents a brief overview of the physics with the 15-30~GeV continuous beam electron facility proposed by the European community of nuclear physicists to study the quark and gluon structure of hadrons.Comment: need qcdparis.sty, psfig and 8 eps figures : exclusive_hard_1.eps exclusive_hard_2.eps exclusive_hard_3.eps hard_bw.eps gpm_slac.eps inclusif1.eps inclusif2.eps machine.ep

    Bubble concentration on spheres for supercritical elliptic problems

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    We consider the supercritical Lane-Emden problem (P_\eps)\qquad -\Delta v= |v|^{p_\eps-1} v \ \hbox{in}\ \mathcal{A} ,\quad u=0\ \hbox{on}\ \partial\mathcal{A} where A\mathcal A is an annulus in \rr^{2m}, m2m\ge2 and p_\eps={(m+1)+2\over(m+1)-2}-\eps, \eps>0. We prove the existence of positive and sign changing solutions of (P_\eps) concentrating and blowing-up, as \eps\to0, on (m1)(m-1)-dimensional spheres. Using a reduction method (see Ruf-Srikanth (2010) J. Eur. Math. Soc. and Pacella-Srikanth (2012) arXiv:1210.0782)we transform problem (P_\eps) into a nonhomogeneous problem in an annulus \mathcal D\subset \rr^{m+1} which can be solved by a Ljapunov-Schmidt finite dimensional reduction
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