1,460 research outputs found

    An Empirical Evaluation of The Relationship of Market Value Added with Internal Company Characteristics

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    The window dressing of jinanc/al statements creates problems for investment decision making. This necessitates the use of other measures that capture the fundamental economic reality of the organization. This paper seeks to examine the relationship between market value added and the internal performance characteristics and how this affects share prices. The paper using OLS regression technique shows that Market Value Added is highly correlated with Economic Value Added than other internal company characteristics. The import of this is that, for management to increase market value added it must concentrate on increasing its Economic Value Adde

    CP violation in unpolarized e^+ e^- to charginos at one loop level

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    We study CP violation in e^+ e^- to \tilde\chi_i^+\tilde\chi_j^- in the framework of the MSSM. Though the cross section of this process is CP-even at the tree level even for polarized electron-positron beams, we show that it contains a CP-odd part at the one loop order and there are CP-odd observables that can in principle be measured even using unpolarized electron-positron beams. The relevant diagram calculations are briefly discussed and the results of selected (box) diagram computations are shown.Comment: similar to Phys. Rev. D version, but corrected figs. 4, 5, 6 (factor four

    Multi-lepton Signatures of a Hidden Sector in Rare B Decays

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    We explore the sensitivity of flavour changing b -> s transitions to a (sub-)GeV hidden sector with generic couplings to the Standard Model through the Higgs, vector and axion portals. The underlying two-body decays of B mesons, B -> X_s S and B0 -> SS, where S denotes a generic new GeV-scale particle, may significantly enhance the yield of monochromatic lepton pairs in the final state via prompt decays of S to a dilepton pair. Existing measurements of the charged lepton spectrum in neutral-current semileptonic B decays provide bounds on the parameters of the light sector that are significantly more stringent than the requirements of naturalness. New search modes, such as B -> X_s + n(l+l-) and B0 -> n(l+l-) with n > 1 can provide additional sensitivity to scenarios in which both the Higgs and vector portals are active, and are accessible to (super-)B factories and hadron colliders.Comment: 12 pages, 2 figures; v2: reference added, minor correction

    Constraints on the variability of quark masses from nuclear binding

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    Based on recent work on nuclear binding, we update and extend the anthropic constraints on the light quark masses, with results that are more tightly constrained than previously obtained. We find that heavy nuclei would fall apart (because the attractive nuclear central potential becomes too weak) if the sum of the light quark masses m_u+m_d would exceed their physical values by 64% (at 95% confidence level). We summarize the anthropic constraints that follow from requiring the existence both of heavy atoms and of hydrogen. With the additional assumption that the quark Yukawa couplings do not vary, these constraints provide a remarkably tight anthropic window for the Higgs vacuum expectation value: 0.39 < v/v_physical < 1.64.Comment: 21 pages, 7 figure

    Lepton Polarization in the Decays BXsμ+μB\to X_s\mu^+\mu^- and BXsτ+τB\to X_s\tau^+\tau^-

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    The effective Hamiltonian for the decay bsl+lb\to s l^+ l^- predicts a characteristic polarization for the final state lepton, which can serve as an important test of the underlying theory. The lepton polarization has, in addition to a longitudinal component PLP_L, two orthogonal components PTP_T and PNP_N, lying in and perpendicular to the decay plane which are proportional to ml/mbm_l/m_b, and therefore significant for the τ+τ\tau^+\tau^- channel. The normal polarization component PNP_N is a TT-odd effect connected with the nonhermiticity of the effective Hamiltonian, arising mainly from ccˉc\bar{c} intermediate states. We calculate all three polarization components for the decay BXsτ+τB\to X_s\tau^+\tau^- as a function of the lepton pair mass, and find average values =0.37, = -0.37, = -0.63, = 0.03. By comparison, the $\mu^-$ polarization is = -0.77, =0 = \approx 0.Comment: 17 pages, LaTeX, 5 eps figures, uses epsf.sty and cite.st

    Models of Electroweak Interactions in Non-Commutative Geometry: A Comparison

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    Alain Connes' construction of the standard model is based on a generalized Dirac-Yukawa operator and the K-cycle (\HD ,D), with \HD a fermionic Hilbert space. If this construction is reformulated at the level of the differential algebra then a direct comparison with the alternative approach by the Marseille-Mainz group becomes possible. We do this for the case of the toy model based on the structure group U(1)×U(1)U(1)\times U(1) and for the SU(2)×U(1)SU(2)\times U(1) of electroweak interactions. Connes' results are recovered without the somewhat disturbing γ5\gamma_{5}-factors in the fermion mass terms and Yukawa couplings. We discuss both constructions in the same framework and, in particular, pinpoint the origin of the difference in the Higgs potential obtained by them.Comment: 9p, MZ-TH/93-2

    `c' is the speed of light, isn't it?

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    Theories proposing a varying speed of light have recently been widely promoted under the claim that they offer an alternative way of solving the standard cosmological problems. Recent observational hints that the fine structure constant may have varied during over cosmological scales also has given impetus to these models. In theoretical physics the speed of light, cc, is hidden in almost all equations but with different facets that we try to distinguish. Together with a reminder on scalar-tensor theories of gravity, this sheds some light on these proposed varying speed of light theories.Comment: 14 pages, Late

    Neutrino statistics and big bang nucleosynthesis

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    Neutrinos may possibly violate the spin-statistics theorem, and hence obey Bose statistics or mixed statistics despite having spin half. We find the generalized equilibrium distribution function of neutrinos which depends on a single fermi-bose parameter, \kappa, and interpolates continuously between the bosonic and fermionic distributions when \kappa changes from -1 to +1. We consider modification of the Big Bang Nucleosynthesis (BBN) in the presence of bosonic or partly bosonic neutrinos. For pure bosonic neutrinos the abundances change (in comparison with the usual Fermi-Dirac case) by -3.2% for 4He (which is equivalent to a decrease of the effective number of neutrinos by \Delta N_\nu = - 0.6), +2.6% for 2H and -7% for 7Li. These changes provide a better fit to the BBN data. Future BBN studies will be able to constrain the fermi-bose parameter to \kappa > 0.5, if no deviation from fermionic nature of neutrinos is found. We also evaluate the sensitivity of future CMB and LSS observations to the fermi-bose parameter.Comment: 11 pages, 3 figures, matches version in JCAP, discussion and references extended slightl

    't Hooft tensor for generic gauge group

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    We study monopoles in gauge theories with generic gauge group. Magnetic charges are in one-to-one correspondence with the second homotopy classes at spatial infinity (Π2{\Pi}_2), which are therefore identified by the 't Hooft tensor. We determine the 't Hooft tensor in the general case. These issues are relevant to the understanding of Color Confinement.Comment: 5 pages. Contribution to the Conference QCD08, Montpellier 7-12 July 2008 To appear in the proceeding

    Final-State-Interaction Simulation of T-Violation in the Top-Quark Semileptonic Decay

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    The standard electroweak final-state interaction induces a false T-odd correlation in the top-quark semileptonic decay. The correlation parameter is calculated in the standard model and found to be considerably larger than those that could be produced by genuine T-violation effects in a large class of theoretical models.Comment: 14 pages, 1 diagram (not included
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