3,757 research outputs found
Catalogo analitico
No full textThis essay investigates the liturgical-musical codes of the Cathedral, the St. Francis Convent and the Monastery of St. Clare in Oristano (XI-XVII centuries), on the basis of an international critical approach and a new interdisciplinary and descriptive model. The manuscripts considered form part of the only collection of liturgy books illuminated with neums in Sardinia. The majority of codes and the iconography – 18 manuscripts and numerous fragments, c.a. 3,400 parchments, 159 illuminations – were unpublished, with the only exception of a inventory with wrong datations (Lucca, 1911). All of the liturgical and musical formularies, and the biblical references have been traced and collated with the main repertoires. This study also shows cross references with a historical analysis and a critical Glossary by the author, published in the same volume and edited by the author himself (a CDRom is included). Among the codes is the corpus ACO P. III-VIII, a monumental Antiphonary in 6 volumes produced in the Tuscan-Emilian area in the XIII4/4 century. This is one of the most important sources of the Roman-Franciscan ritual after the reformations of Haymo of Faversham (1244) and Nicholas III (1277-1280). Hundreds of its facsimiles, in colour, have been considered. A bibliography of 274 references provides the primary research tools in the area of liturgical-musical code analysis
Higgs-boson-plus-photon production at the CERN Large Hadron Collider: A clean probe of the b-quark parton densities
No full textHiggs boson production in association with a high p(T) photon at the CERN Large Hadron Collider is analyzed, in the framework of the MSSM model, for the heavier neutral Higgs bosons. The request of an additional photon in the exclusive Higgs boson final state selects b-quark pairs among the possible initial partonic states, since gluon-gluon initial states are not allowed by C-parity conservation. Hence, the measurement of cross sections for neutral Higgs boson plus photon production can provide a clean probe of the b-quark density in the proton as well as of the b-quark Yukawa coupling. The suppression of the production rates by the b-quark electromagnetic coupling can be compensated by the enhanced Higgs boson Yukawa coupling to b's in the large tan beta regime. The Higgs boson decay into a tau-lepton pair is considered, and irreducible backgrounds with corresponding signal significances are evaluated
Gravitational decays of heavy particles in large extra dimensions
No full textIn the framework of quantum gravity propagating in large extra dimensions, we analyze the inclusive radiative emission of Kaluza-Klein spin-2 gravitons in the two-fermions decays of massive gauge bosons, heavy quarks, Higgs bosons, and in the two-massive gauge bosons decay of Higgs bosons. We provide analytical expressions for the square modulus of amplitudes summed over polarizations, and numerical results for the widths and branching ratios. The corresponding decays in the , top quark, and Higgs boson sectors of the standard model are analyzed in the light of present and future experiments.In the framework of quantum gravity propagating in large extra dimensions, we analyze the inclusive radiative emission of Kaluza-Klein spin-2 gravitons in the two-fermions decays of massive gauge bosons, heavy quarks, Higgs bosons, and in the two-massive gauge bosons decay of Higgs bosons. We provide analytical expressions for the square modulus of amplitudes summed over polarizations, and numerical results for the widths and branching ratios. The corresponding decays in the Z, top quark, and Higgs boson sectors of the standard model are analyzed in the light of present and future experiments.In the framework of quantum gravity propagating in large extra dimensions, we analyze the inclusive radiative emission of Kaluza–Klein spin-2 gravitons in the two-fermions decays of massive gauge bosons, heavy quarks, Higgs bosons, and in the two-massive gauge bosons decay of Higgs bosons. We provide analytical expressions for the square modulus of amplitudes summed over polarizations, and numerical results for the widths and branching ratios. The corresponding decays in the Z , top quark, and Higgs boson sectors of the standard model are analyzed in the light of present and future experiments
Testing Effective Yukawa Couplings in Higgs Searches at Tevatron and LHC
No full textWe explore the possibility that, while the Higgs mechanism provides masses to the weak-gauge bosons at the electroweak scale as in the standard model, fermion masses are generated by an unknown mechanism at a higher energy scale. At low energies, the standard model can then be regarded as an effective field theory, where fermion masses explicitly break the electroweak SU(2)_L \times U(1)_Y gauge symmetry. If \Lambda is the renormalization scale where the renormalized Yukawa couplings vanish, at energies lower than \Lambda, effective Yukawa couplings will be radiatively induced by nonzero fermion masses. In this scenario, Higgs-boson decays into photons and weak gauge-bosons pairs are in general quite enhanced for a light Higgs. However, depending on \Lambda, a substantial decay rate into b \bar{b} can arise, that can be of the same order, or larger than, the enhanced H\to gamma gamma rate. A new framework for Higgs searches at hadron colliders is outlined, vector-boson fusion becoming the dominant production mechanism at the CERN LHC. A detailed analysis of the Higgs branching fractions and their implications in Higgs searches is provided, versus the energy scale \Lambda.We explore the possibility that, while the Higgs mechanism provides masses to the weak-gauge bosons at the electroweak scale as in the standard model, fermion masses are generated by an unknown mechanism at a higher energy scale. At low energies, the standard model can then be regarded as an effective field theory, where fermion masses explicitly break the electroweak SU(2)_L \times U(1)_Y gauge symmetry. If \Lambda is the renormalization scale where the renormalized Yukawa couplings vanish, then at energies lower than \Lambda, effective Yukawa couplings will be radiatively induced by nonzero fermion masses. In this scenario, Higgs-boson decays into photons and weak gauge-bosons pairs are in general quite enhanced for a light Higgs. However, depending on \Lambda, a substantial decay rate into b \bar{b} can arise, that can be of the same order as, or larger than, the enhanced H\to gamma gamma rate. A new framework for Higgs searches at hadron colliders is outlined, vector-boson fusion becoming the dominant production mechanism at the CERN LHC, with an important role also played by the WH/ZH associated production. A detailed analysis of the Higgs branching fractions and their implications in Higgs searches is provided, versus the energy scale \Lambda
Mapping the spatial variation of soil moisture at the large scale using GPR for pavement applications
No full textThe characterization of shallow soil moisture spatial variability at the large scale is a crucial issue in many research studies and fields of application ranging from agriculture and geology to civil and environmental engineering. In this framework, this work contributes to the research in the area of pavement engineering for preventing damages and planning effective management. High spatial variations of subsurface water content can lead to unexpected damage of the load-bearing layers; accordingly, both safety and operability of roads become lower, thereby affecting an increase in expected accidents. \ud
A pulsed ground-penetrating radar system with ground-coupled antennas, i.e., 600-MHz and 1600-MHz center frequencies of investigation, was used to collect data in a 16 m × 16 m study site in the Po Valley area in northern Italy. Two ground-penetrating radar techniques were employed to non-destructively retrieve the subsurface moisture spatial profile. The first technique is based on the evalu¬ation of the dielectric permittivity from the attenuation of signal amplitudes. Therefore, dielectrics were converted into moisture values using soil-specific coefficients from Topp’s relationship. Ground-penetrating-radar-derived values of soil moisture were then compared with measurements from eight capacitance probes. The second technique is based on the Rayleigh scattering of the signal from the Fresnel theory, wherein the shifts of the peaks of frequency spectra are assumed comprehensive indi¬cators for characterizing the spatial variability of moisture. Both ground-penetrating radar methods have shown great promise for mapping the spatial variability of soil moisture at the large scale
ZγH Vertex Effects at Future Colliders
No full textWe show that the Higgs production in e gamma collisions, through the one-loop reaction e gamma \to eH at large transverse momentum, can provide a precise determination of the Z gamma H vertex. We concentrate on the analysis of signal rates vs background looking for strategies to improve the ratio S/B. Possible bounds on anomalous contributions to the Z gamma H vertex are derived
A Combined Experimental and Theoretical Study on the Stereodynamics of Monoaza[5]helicenes: Solvent-Induced Increase of the Enantiomerization Barrier in 1-Aza-[5]helicene
No full textHelicenes and heterohelicenes are attractive compounds with great potential in materials sciences to be used in optoelectronics as ligand backbones in enantioselective catalysis and as chiral sensors.[1] Synthetic protocols were developed to obtain helicenes with skeletons consisting of ortho-fused benzene rings or analogue structures incorporating a heteroatom, as in thiophene-, furane-, or pyridine-containing helicenes.[2] In recent years, a repertoire of synthetic strategies was developed to access all monoaza[5]helicenes as well as some diaza[ 5]helicenes.[3] The properties of these materials are related to the stereodynamics of these helical chiral compounds. By exploration of the unexpected broad range of physicochemical properties of aza[n]helicenes it was realized that there is an opportunity to modulate a specific property by controlled design of the position of the N atoms in the helical molecular frame. In this contribution, we show a complete stereodynamic characterization of monoaza[5]-helicenes combining enantioselective dynamic HPLC and DFT calculations. At variance with previous theoretical calculations[4], 1-aza[5]helicene shows a surprisingly high enantiomerization barrier, which is triggered by specific solvent interactions. [5]
References
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Virtual graviton exchanges at the Z pole in large extra dimensions
No full textIn the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein gravitons on the imaginary part of the amplitude of the process e(+)e(-) --> f (f) over bar are analyzed at the Z pole. Notably, the interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Planck scale M-D. We find that, while the virtual-graviton effect on total cross sections vanishes at tree-level, both angular and polarization asymmetries are modified by terms whose relative effect is at most of order 10(-4) for M-D > 1 TeV. Possible shifts in M-Z, due to the changes in Breit-Wigner line shape are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved
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