3,038 research outputs found

    Note on Anomalous Higgs-Boson Couplings in Effective Field Theory

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    We propose a parametrization of anomalous Higgs-boson couplings that is both systematic and practical. It is based on the electroweak chiral Lagrangian, including a light Higgs boson, as the effective field theory (EFT) at the electroweak scale vv. This is the appropriate framework for the case of sizeable deviations in the Higgs couplings of order 10%10\% from the Standard Model, considered to be parametrically larger than new-physics effects in the sector of electroweak gauge interactions. The role of power counting in identifying the relevant parameters is emphasized. The three relevant scales, vv, the scale of new Higgs dynamics ff, and the cut-off Λ=4πf\Lambda=4\pi f, admit expansions in ξ=v2/f2\xi=v^2/f^2 and f2/Λ2f^2/\Lambda^2. The former corresponds to an organization of operators by their canonical dimension, the latter by their loop order or chiral dimension. In full generality the EFT is thus organized as a double expansion. However, as long as ξ≫1/16π2\xi\gg 1/16\pi^2 the EFT systematics is closer to the chiral counting. The leading effects in the consistent approximation provided by the EFT, relevant for the presently most important processes of Higgs production and decay, are given by a few (typically six) couplings. These parameters allow us to describe the properties of the Higgs boson in a general and systematic way, and with a precision adequate for the measurements to be performed at the LHC. The framework can be systematically extended to include loop corrections and higher-order terms in the EFT.Comment: 7 pages, no figures; typos corrected; references adde

    Normally ordered forms of powers of differential operators and their combinatorics

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    We investigate the combinatorics of the general formulas for the powers of the operator h∂k, where h is a central element of a ring and ∂ is a differential operator. This generalizes previous work on the powers of operators h∂. New formulas for the generalized Stirling numbers are obtained.Ministerio de Economía y competitividad MTM2016-75024-PJunta de Andalucía P12-FQM-2696Junta de Andalucía FQM–33

    Complete One-Loop Renormalization of the Higgs-Electroweak Chiral Lagrangian

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    Employing background-field method and super-heat-kernel expansion, we compute the complete one-loop renormalization of the electroweak chiral Lagrangian with a light Higgs boson. Earlier results from purely scalar fluctuations are confirmed as a special case. We also recover the one-loop renormalization of the conventional Standard Model in the appropriate limit.Comment: 15 pages, no figures; v2: reference and comments added, typos fixed, matches published versio

    Hybridization between wild and cultivated potato species in the Peruvian Andes and biosafety implications for deployment of GM potatoes

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    The nature and extent of past and current hybridization between cultivated potato and wild relatives in nature is of interest to crop evolutionists, taxonomists, breeders and recently to molecular biologists because of the possibilities of inverse gene flow in the deployment of genetically-modified (GM) crops. This research proves that natural hybridization occurs in areas of potato diversity in the Andes, the possibilities for survival of these new hybrids, and shows a possible way forward in case of GM potatoes should prove advantageous in such areas

    Authors' reply to Colquhoun and Buchinsky

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