1,751 research outputs found

    Precise nondivergent analytic formulas for the radiative corrections to the beta energy spectrum in hyperon semileptonic decays over the entire Dalitz plot

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    Very accurate analytical expressions for the radiative corrections of unpolarized hyperons semileptonic decays of charged and neutral baryons have been obtained in the recent past. Some of these formulas contain logarithmic singularities at the edges of the Dalitz plot for the three- and four-body decays. These singularities are analyzed and integrated analytically to obtain new divergentless formulas for the energy spectrum of the produced beta particle. The new equations contain terms of the order alpha times the momentum transfer, are applicable to any beta decay process and are suitable for a model-independent experimental analysis.Comment: 22 pages, 4 figure

    Precise bounds on the Higgs boson mass

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    We study the renormalization group evolution of the Higgs quartic coupling λH\lambda_{H} and the Higgs mass mHm_{H} in the Standard Model. The one loop equation for λH\lambda_{H} is non linear and it is of the Riccati type which we numerically and analytically solve in the energy range [mt,EGU][m_{t},E_{GU}] where mtm_{t} is the mass of the top quark and EGU=1014E_{GU}=10^{14} GeV. We find that depending on the value of λH(mt)\lambda_{H}(m_{t}) the solution for λH(E)\lambda_{H}(E) may have singularities or zeros and become negative in the former energy range so the ultra violet cut off of the standard model should be below the energy where the zero or singularity of λH\lambda_{H} occurs. We find that for 0.369≤λH(mt)≤0.6130.369\leq\lambda_{H}(m_{t})\leq0.613 the Standard Model is valid in the whole range [mt,EGU][m_{t},E_{GU}]. We consider two cases of the Higgs mass relation to the parameters of the standard model: (a) the effective potential method and (b) the tree level mass relations. The limits for λH(mt)\lambda_{H}(m_{t}) correspond to the following Higgs mass relation 150≤mH⪅193150\leq m_{H}\lessapprox 193 GeV. We also plot the dependence of the ultra violet cut off on the value of the Higgs mass. We analyze the evolution of the vacuum expectation value of the Higgs field and show that it depends on the value of the Higgs mass. The pattern of the energy behavior of the VEV is different for the cases (a) and (b). The behavior of λH(E)\lambda_{H}(E), mH(E)m_{H}(E) and v(E)v(E) indicates the existence of a phase transition in the standard model. For the effective potential this phase transition occurs at the mass range mH≈180m_{H}\approx 180 GeV and for the tree level mass relations at mH≈168m_{H}\approx 168 GeV.Comment: 14 pages, 7 figures. Expanded the discussion of the Higgs mass relation between the parameters of the Standard Model. Included the method of the Higgs effective potentia

    Mode solutions for a Klein-Gordon field in anti-de Sitter spacetime with dynamical boundary conditions of Wentzell type

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    We study a real, massive Klein-Gordon field in the Poincar\'e fundamental domain of the (d+1)(d+1)-dimensional anti-de Sitter (AdS) spacetime, subject to a particular choice of dynamical boundary conditions of generalized Wentzell type, whereby the boundary data solves a non-homogeneous, boundary Klein-Gordon equation, with the source term fixed by the normal derivative of the scalar field at the boundary. This naturally defines a field in the conformal boundary of the Poincar\'e fundamental domain of AdS. We completely solve the equations for the bulk and boundary fields and investigate the existence of bound state solutions, motivated by the analogous problem with Robin boundary conditions, which are recovered as a limiting case. Finally, we argue that both Robin and generalized Wentzell boundary conditions are distinguished in the sense that they are invariant under the action of the isometry group of the AdS conformal boundary, a condition which ensures in addition that the total flux of energy across the boundary vanishes.Comment: 12 pages, 1 figure. In V3: refs. added, introduction and conclusions expande

    Assessment of practitioners' interactions with academically driven curriculum

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    Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 39-41).A growing interest in innovation-based entrepreneurship has surfaced in much of world, producing a large body of related research and capturing the attention of those aiming to direct and improve the economic impact of "practitioners'" home regions. With growing research and limited examples of newly created and successful entrepreneurial communities formed, a dear gap has emerged between what the literature describes and suggests for the creation of entrepreneurial communities, and what practitioners are able to achieve. This thesis assesses how the MIT Regional Entrepreneurship Acceleration Program (REAP), a program formed as a way to address these shortfalls, has achieved lasting and meaningful impact for practitioners who have participated in the program.by Beto Juárez III.M.B.A
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