46,271 research outputs found
The Higgs sector of the minimal SUSY model
I review the Higgs sector of the extension of the minimal
supersymmetric standard model (MSSM). I will show that the gauge kinetic mixing
plays a crucial role in the Higgs phenomenology. Two light bosons are present,
a MSSM-like one and a -like one, that mix at one loop solely due to the
gauge mixing. After briefly looking at constraints from flavour observables,
new decay channels involving right-handed (s)neutrinos are presented. Finally,
it will be reviewed how model features pertaining to the gauge extension affect
the model phenomenology, concerning the existence of R-Parity-conserving minima
at loop level and the Higgs-to-diphoton coupling.Comment: 10 pages, 17 figures, 2 tables. v2, to appear in "Supersymmetry
beyond the NMSSM". Shortened model description, added a section concerning
the R-parity conservation, typos corrected. arXiv admin note: text overlap
with arXiv:1112.4600 by other author
Minimal Z' models and the 125 GeV Higgs boson
The 1-loop renormalization group equations for the minimal Z' models
encompassing a type-I seesaw mechanism are studied in the light of the 125 GeV
Higgs boson discovery. This model is taken as a benchmark for the general case
of singlet extensions of the standard model. The most important result is that
negative scalar mixing angles are favoured with respect to positive values.
Further, a minimum value for the latter exists, as well as a maximum value for
the masses of the heavy neutrinos, depending on the vacuum expectation value of
the singlet scalar.Comment: 12 pages, 4 figures. Corrected Eq.(8) and according references,
affecting only heavy neutrino masses (values half than before). Other results
unchange
Enhancing with staus in SUSY models with extended gauge sector
We discuss the impact on the stau masses of the additional D-terms in
U(1)-extended MSSM models. We show, explicitly for the B-L-SSM, that these
contributions can play a crucial role in the explanation of the enhanced
diphoton decay rate of a SM-like Higgs particle around 125 GeV. Even in the
most constrained scenario with universal scalar and gaugino masses, it is
possible to obtain a sizable enhancement and, in addition, the correct relic
density for the LSP. Furthermore, a lighter CP-even scalar that could fit the
LEP excess at 98 GeV is viable.Comment: 5 pages, 3 figures, 2 table
Investment cost channel and monetary transmission
Copyright @ 2011 Central Bank Review. This article is available open access through the publisher’s website at the link below.We show that a standard DSGE model with investment cost channels has
important model stability and policy implications. Our analysis suggests that in
economies characterized by supply side well as demand side channels of monetary
transmission, policymakers may have to resort to a much more aggressive stand against
inflation to obtain locally unique equilibrium. In such an environment targeting output
gap may cause model instability. We also show that it is difficult to distinguish
between the New Keynesian model and labor cost channel only case, while with
investment cost channel differences are more significant. This result is important as it
suggests that if one does not take into account the investment cost channel, one is
underestimating the importance of supply side effects
The future of bioethanol
Yeasts have been domesticated by mankind before horses. After the mastering of alcoholic fermentation for centuries, yeasts have become the protagonist of one of the most important biotechnological industries worldwide: the production of bioethanol. This chapter will initially present some important challenges to be overcome in this industry, both in first and second generation biofuel production. Then, it will briefly revisit some advances obtained in recent years. Finally, it will present and discuss some opportunities, in the scope of metabolic engineering and synthetic biology, that will likely be present in the future of bioethanol
A Shortcut to General Tree-level Scattering Amplitudes in N=4 SYM via Integrability
© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, WeinheimWe combine recent applications of the two-dimensional quantum inverse scattering method to the scattering amplitude problem in four-dimensional N=4 Super Yang-Mills theory. Integrability allows us to obtain a general, explicit method for the derivation of the Yangian invariants relevant for tree-level scattering amplitudes in the N=4 model.Peer reviewe
A preliminary energy analysis of a commercial chp fueled with h2ng blends chemically supercharged by renewable hydrogen and oxygen
Currently, Power-to-Gas technologies are considered viable solutions to face the onset problems associated with renewable capacity firming. Indeed, carbon-free hydrogen production converting renewable electricity excess and its injection into natural gas pipelines is considered a short- to medium-term solution. In this way, the so-called H2NG blends can be fired within internal combustion engines and micro gas turbines operating in CHP mode, offering better environmental-energy performances in machines. As regards the distributed energy generation scenario, the local H2 production by means of electrolysis for methane enrichment will be more cost-effective if the oxygen is fruitfully used instead of venting it out like a by-product, as usually occurs. This study focuses on the usefulness of using that oxygen to enrich the air-fuel mixture of an internal combustion engine for micro-CHP applications, once it has been fuelled with H2NG blends. Thus, the main aim of this paper is to provide a set of values for benchmarking, in which H2NG blends, ranging in 0%-15% vol., burn within an ICE in partial oxy-fuel conditions. In particular, a preliminary energy analysis was carried out based on experimental data, reporting the engine operating parameters, gains and losses in both electrical and heat recovery efficiency. The oxygen content in the air varies up to 22% vol. A Volkswagen Blue Tender CHP commercial version (19.8 kWel. of rated electrical power output) was considered as the reference machine and its energy characterization was reported when it operated under those unconventional conditions
Hexagonal Wilson Loops in Planar SYM Theory at Finite Coupling
We report on the complete OPE series for the 6-gluon MHV and NMHV amplitudes
in planar SYM theory. Namely, we provide a finite coupling
prediction for all the terms in the expansion of these amplitudes around the
collinear limit. These furnish a non-perturbative representation of the full
amplitudes.Comment: 2 pages + reference
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