1,221 research outputs found

    (B-L) Symmetry vs. Neutrino Seesaw

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    We compute the effective coupling of the Majoron to W bosons at \cO(\hbar) by evaluating the matrix element of the (B-L) current between the vacuum and a W+WW^+W^- state. The (B-L) anomaly vanishes, but the amplitude does not vanish as a result of a UV finite and non-local contribution which is entirely due to the mixing between left-chiral and right-chiral neutrinos. The result shows how anomaly-like couplings may arise in spite of the fact that the (B-L) current remains exactly conserved to all orders in \hbar, lending additional support to our previous proposal to identify the Majoron with the axion.Comment: 13 pages, 1 figure, with additional explanations and clarification

    Flexible production and entry: institutional, technological, and organizational determinants

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    Academics, the media, and policymakers have all raised concerns about the implications of human workers being replaced by machines or software. Few have discussed the implications of the reverse: firms’ ability to replace capital with workers. We show that this flexibility can help new firms overcome uncertainty and increase entrepreneurial entry. We develop a simple real options model where permissive labor regulations allow firms to take advantage of capital-labor substitutability by replacing ‘rigid’ capital with ‘flexible’ labor. The model highlights institutional, technological, and organizational preconditions to using this flexibility. Using a large and comprehensive dataset on entry by standalone firms and group affiliates, we provide evidence in support of the model

    A disilene base adduct with a dative Si–Si single bond.

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    An experimental and theoretical study of the base- stabilized disilene 1 is reported, whichforms at lowtemper- atures in the disproportionation reaction of Si 2 Cl 6 or neo- Si 5 Cl 12 with equimolar amounts of NMe 2 Et. Single-crystal X- ray diffraction and quantum-chemical bonding analysis dis- close an unprecedented structure in silicon chemistry featuring adative Si!Si single bond between two silylene moieties, Me 2 EtN!SiCl 2 !Si(SiCl 3 ) 2 .The central ambiphilic SiCl 2 group is linked by dative bonds to the amine donor and the bis(trichlorosilyl)silylene acceptor,which leads to push–pull stabilization. Based on experimental and theoretical examina- tions aformation mechanism is presented that involves an autocatalytic reaction of the intermediately formed anion Si(SiCl 3 ) 3 ¢ with neo-Si 5 Cl 12 to yield 1

    An Optimal Execution Problem with Market Impact

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    We study an optimal execution problem in a continuous-time market model that considers market impact. We formulate the problem as a stochastic control problem and investigate properties of the corresponding value function. We find that right-continuity at the time origin is associated with the strength of market impact for large sales, otherwise the value function is continuous. Moreover, we show the semi-group property (Bellman principle) and characterise the value function as a viscosity solution of the corresponding Hamilton-Jacobi-Bellman equation. We introduce some examples where the forms of the optimal strategies change completely, depending on the amount of the trader's security holdings and where optimal strategies in the Black-Scholes type market with nonlinear market impact are not block liquidation but gradual liquidation, even when the trader is risk-neutral.Comment: 36 pages, 8 figures, a modified version of the article "An optimal execution problem with market impact" in Finance and Stochastics (2014

    Higgs mass implications on the stability of the electroweak vacuum

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    We update instability and metastability bounds of the Standard Model electroweak vacuum in view of the recent ATLAS and CMS Higgs results. For a Higgs mass in the range 124--126 GeV, and for the current central values of the top mass and strong coupling constant, the Higgs potential develops an instability around 101110^{11} GeV, with a lifetime much longer than the age of the Universe. However, taking into account theoretical and experimental errors, stability up to the Planck scale cannot be excluded. Stability at finite temperature implies an upper bound on the reheat temperature after inflation, which depends critically on the precise values of the Higgs and top masses. A Higgs mass in the range 124--126 GeV is compatible with very high values of the reheating temperature, without conflict with mechanisms of baryogenesis such as leptogenesis. We derive an upper bound on the mass of heavy right-handed neutrinos by requiring that their Yukawa couplings do not destabilize the Higgs potential.Comment: 14 pages, 8 figure

    Corporate governance compliance and disclosure in the banking sector: using data from Japan

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    Using regression model this study investigates which characteristics of a bank is associated with the extent of corporate governance disclosure in Japan. The findings suggest that on average 8 banks out of a sample of 46 disclose optimal corporate governance information. The regression model results reveal in general that non-executive directors, cross-ownership, capital adequacy ratio and type of auditors are associated with the extent of corporate governance disclosure. Of these four variables, non-executive directors have a more significant impact on the extent of disclosure contrary to total assets and audit firms of banks in the context of Japan. The findings of this paper are relevant for corporate regulators, professional associations and developers of corporate governance code when designing or updating corporate governance code

    Planck Scale Boundary Conditions and the Higgs Mass

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    If the LHC does only find a Higgs boson in the low mass region and no other new physics, then one should reconsider scenarios where the Standard Model with three right-handed neutrinos is valid up to Planck scale. We assume in this spirit that the Standard Model couplings are remnants of quantum gravity which implies certain generic boundary conditions for the Higgs quartic coupling at Planck scale. This leads to Higgs mass predictions at the electroweak scale via renormalization group equations. We find that several physically well motivated conditions yield a range of Higgs masses from 127-142 GeV. We also argue that a random quartic Higgs coupling at the Planck scale favors M_H > 150 GeV, which is clearly excluded. We discuss also the prospects for differentiating different boundary conditions imposed for \lambda(M_{pl}) at the LHC. A striking example is M_H = 127\pm 5 GeV corresponding to \lambda(M_{pl})=0, which would imply that the quartic Higgs coupling at the electroweak scale is entirely radiatively generated.Comment: 12 pages, 5 figures; references added and other minor improvements, matches version published in JHE

    The impact of inflation risk on forward trading and production

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    This paper examines the behavior of a competitive firm that faces joint price and inflation risk. Given that the price risk is negatively correlated with the inflation risk in the sense of expectation dependence, we show that the firm optimally opts for an over-hedge (under-hedge) if the firm’s coefficient of relative risk aversion is everywhere no greater (no smaller) than unity. We show further that banning the firm from forward trading may induce the firm to produce more or less, depending on whether the price risk premium is positive or negative, respectively. While the price risk premium is unambiguously negative in the absence of the inflation risk, it is not the case when the inflation risk prevails. In contrast to the conventional wisdom, forward hedging needs not always promote production should firms take inflation seriously.info:eu-repo/semantics/publishedVersio
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