23,989 research outputs found

    Color-octet scalar effects on Higgs boson production in gluon fusion

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    We compute the next-to-next-to-leading order QCD corrections to the gluon-fusion production of a Higgs boson in models with massive color-octet scalars in the (8,1)0{\bf (8,1)_0} representation using an effective-theory approach. We derive a compact analytic expression for the relevant Wilson coefficient, and explain an interesting technical aspect of the calculation that requires inclusion of the quartic-scalar interactions at next-to-next-to-leading order. We perform a renormalization-group analysis of the scalar couplings to derive the allowed regions of parameter space, and present phenomenological results for both the Tevatron and the LHC. The modifications of the Higgs production cross section are large at both colliders, and can increase the Standard Model rate by more than a factor of two in allowed regions of parameter space. We estimate that stringent constraints on the color-octet scalar parameters can be obtained using the Tevatron exclusion limit on Higgs production.Comment: 18 pages, 6 figures, 3 table

    Subluminal OPERA Neutrinos

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    The OPERA collaboration has announced to have observed superluminal neutrinos with a mean energy 17.5 GeV, but afterward the superluminal interpretation of the OPERA results has been refuted theoretically by Cherenkov-like radiation and pion decay. In a recent work, we have proposed a kinematical resolution to this problem. A key idea in our resolution is that the OPERA neutrinos are not superluminal but subluminal since they travel faster than the observed speed of light in vacuum on the earth while they do slower than the true speed of light in vacuum determining the causal structure of events. In this article, we dwell upon our ideas and present some concrete models, which realize our ideas, based on spin 0, 1 and 2 bosonic fields. We also discuss that the principle of invariant speed of light in special relativity can be replaced with the principle of a universal limiting speed.Comment: 17 page

    Velocity of Light in Dark Matter with Charge

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    We propose an interesting mechanism to reconcile the recent experiments of the Michelson-Morley type and slowdown of the velocity of light in dark matter with a fractional electric charge when the index of refraction of dark matter depends on the frequency of a photon. After deriving the formula for the velocity of light in a medium with the index of refraction n(ω)n(\omega) in a relativistic regime, it is shown that the local anisotropy of the light speed is proportional to the second order in n(ω)1n(\omega) - 1. This result implies that the experiments of the Michelson-Morley type do not give rise to a stringent constraint on the slowdown of the velocity of light in dark matter with electric charge.Comment: 10 page

    Boundary conditions at spatial infinity for fields in Casimir calculations

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    The importance of imposing proper boundary conditions for fields at spatial infinity in the Casimir calculations is elucidated.Comment: 8 pages, 1 figure, submitted to the Proceedings of The Seventh Workshop QFEXT'05 (Barcelona, September 5-9, 2005

    Electroweak gauge boson production at hadron colliders through O(alpha_s^2)

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    We describe a calculation of the O(alpha_s^2) QCD corrections to the fully differential cross section for W and Z boson production in hadronic collisions. The result is fully realistic in that it includes spin correlations, finite width effects, gamma-Z interference and allows for the application of arbitrary cuts on the leptonic decay products of the W and Z. We have implemented this calculation into a numerical program. We demonstrate the use of this code by presenting phenomenological results for several future LHC analyses and recent Tevatron measurements, including the W cross section in the forward rapidity region and the central over forward cross section ratio.Comment: 11 pages, 4 figure

    APMEC: An Automated Provisioning Framework for Multi-access Edge Computing

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    Novel use cases and verticals such as connected cars and human-robot cooperation in the areas of 5G and Tactile Internet can significantly benefit from the flexibility and reduced latency provided by Network Function Virtualization (NFV) and Multi-Access Edge Computing (MEC). Existing frameworks managing and orchestrating MEC and NFV are either tightly coupled or completely separated. The former design is inflexible and increases the complexity of one framework. Whereas, the latter leads to inefficient use of computation resources because information are not shared. We introduce APMEC, a dedicated framework for MEC while enabling the collaboration with the management and orchestration (MANO) frameworks for NFV. The new design allows to reuse allocated network services, thus maximizing resource utilization. Measurement results have shown that APMEC can allocate up to 60% more number of network services. Being developed on top of OpenStack, APMEC is an open source project, available for collaboration and facilitating further research activities
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