434 research outputs found
Ciudades medias, escalas intermedias y planificación. Procesos potenciales e instrumentos ausentes en Brescia
The ongoing phase of transition, led by processes of globalization and world crisis, has been encouraging the demographic and economic re-centralization towards major and largest cities. This trend urges the analysis of socio-economic and spatial dynamics in medium-sized cities which are historically characterized by manufacturing and entrepreneurial culture. This is the case of Brescia (one of the urban hubs of the North Italy city-region), where a strategic agenda (up to now, missing) could foster the management of trans-scalar urban issues, as well as the development of multi-level governance and planning solutions.La fase de transición en curso, dirigida por procesos de globalización y crisis mundial, ha venido alentando la recentralización demográfica y económica hacia las ciudades más grandes e importantes. Esta tendencia urge a analizar la dinámica socioeconómica y espacial de las ciudades de tamaño medio que se caracterizan históricamente por su cultura manufacturera y empresarial. Este es el caso de Brescia (uno de los nodos urbanos de la ciudad-región del norte de Italia), donde un programa estratégico (hasta ahora inexistente) podría fomentar la gestión de los retos urbanos transescalares, así como el desarrollo de soluciones de gobernanza y planificación multinivel
Two-loop master integrals for the leading QCD corrections to the Higgs coupling to a pair and to the triple gauge couplings and
We compute the two-loop master integrals required for the leading QCD
corrections to the interaction vertex of a massive neutral boson , e.g.
or , with a pair of bosons, mediated by a quark
doublet composed of one massive and one massless flavor. All the external legs
are allowed to have arbitrary invariant masses. The Magnus exponential is
employed to identify a set of master integrals that, around space-time
dimensions, obey a canonical system of differential equations. The canonical
master integrals are given as a Taylor series in , up to
order four, with coefficients written as combination of Goncharov
polylogarithms, respectively up to weight four. In the context of the Standard
Model, our results are relevant for the mixed EW-QCD corrections to the Higgs
decay to a pair, as well as to the production channels obtained by
crossing, and to the triple gauge boson vertices and .Comment: 42 pages, 5 figures, 2 ancillary file
Three-loop master integrals for ladder-box diagrams with one massive leg
The three-loop master integrals for ladder-box diagrams with one massive leg
are computed from an eighty-five by eighty-five system of differential
equations, solved by means of Magnus exponential. The results of the considered
box-type integrals, as well as of the tower of vertex- and bubble-type master
integrals associated to subtopologies, are given as a Taylor series expansion
in the dimensional regulator parameter epsilon = (4-d)/2. The coefficients of
the series are expressed in terms of uniform weight combinations of multiple
polylogarithms and transcendental constants up to weight six. The considered
integrals enter the next-to-next-to-next-to-leading order virtual corrections
to scattering processes like the three-jet production mediated by vector boson
decay, V* -> jjj, as well as the Higgs plus one-jet production in gluon fusion,
pp -> Hj.Comment: 44 pages, 5 figures, 2 ancillary file
Two-Loop Master Integrals for the mixed EW-QCD virtual corrections to Drell-Yan scattering
We present the calculation of the master integrals needed for the two-loop
QCDxEW corrections to and for massless external particles. We treat W and Z bosons
as degenerate in mass. We identify three types of diagrams, according to the
presence of massive internal lines: the no-mass type, the one-mass type, and
the two-mass type, where all massive propagators, when occurring, contain the
same mass value. We find a basis of 49 master integrals and evaluate them with
the method of the differential equations. The Magnus exponential is employed to
choose a set of master integrals that obeys a canonical system of differential
equations. Boundary conditions are found either by matching the solutions onto
simpler integrals in special kinematic configurations, or by requiring the
regularity of the solution at pseudo-thresholds. The canonical master integrals
are finally given as Taylor series around d=4 space-time dimensions, up to
order four, with coefficients given in terms of iterated integrals,
respectively up to weight four.Comment: 1+45 pages, 6 figures, 1 table, 5 ancillary file
Master integrals for the NNLO virtual corrections to scattering in QCD: the non-planar graphs
We complete the analytic evaluation of the master integrals for the two-loop
non-planar box diagrams contributing to the top-pair production in the
quark-initiated channel, at next-to-next-to-leading order in QCD. The integrals
are determined from their differential equations, which are cast into a
canonical form using the Magnus exponential. The analytic expressions of the
Laurent series coefficients of the integrals are expressed as combinations of
generalized polylogarithms, which we validate with several numerical checks. We
discuss the analytic continuation of the planar and the non-planar master
integrals, which contribute to in QCD, as well as
to the companion QED scattering processes and .Comment: 1+26 pages, 4 figures, 1 table, 3 ancillary files. v2: references
added, text partly reworded, results unmodifie
Electroweak vacuum stability and inflation via nonminimal derivative couplings to gravity
We show that the standard model vacuum can be stabilized if all particle propagators are nonminimally coupled to gravity. This is due to a Higgs-background dependent redefinition of the standard model fields: in terms of canonical variables and in the large Higgs field limit, the quantum fluctuations of the redefined fields are suppressed by the Higgs background. Thus, in this regime, quantum corrections to the tree-level electroweak potential are negligible. Finally, we show that in this framework the Higgs boson can be responsible for inflation. Due to a numerical coincidence that originates from the CMB data, inflation can happen if the Higgs boson mass, the top mass, and the QCD coupling lie in a region of the parameter space approximately equivalent than the one allowing for electroweak vacuum stability in the standard Model. We find some (small) regions in the standard model parameter space in which the new interaction "rescues" the electroweak vacuum, which would not be stable in the standard model
A global view on the Higgs self-coupling
The Higgs self-coupling is notoriously intangible at the LHC. It was recently
proposed to probe the trilinear Higgs interaction through its radiative
corrections to single-Higgs processes. This approach however requires to
disentangle these effects from those associated to deviations of other
Higgs-couplings to fermions and gauge bosons. We show that a global fit
exploiting only single-Higgs inclusive data suffers from degeneracies that
prevent one from extracting robust bounds on each individual coupling. We show
how the inclusion of double-Higgs production via gluon fusion, and the use of
differential measurements in the associated single-Higgs production channels
WH, ZH and ttH, can help to overcome the deficiencies of a global
Higgs-couplings fit. In particular, we bound the variations of the Higgs
trilinear self-coupling relative to its SM value to the interval [0.1, 2.3] at
68% confidence level at the high-luminosity LHC, and we discuss the robustness
of our results against various assumptions on the experimental uncertainties
and the underlying new physics dynamics. We also study how to obtain a
parametrically enhanced deviation of the Higgs self-couplings and we estimate
how large this deviation can be in a self-consistent effective field theory
framework.Comment: 41 pages, 6 figures; v2: comments and references added, minor typos
corrected, matches published versio
EL URBANISMO DE LOS GRANDES EVENTOS: OPORTUNIDADES Y RIESGOS PARA EL PATRIMONIO LOCAL
En el ámbito disciplinario de la planificación urbana y territorial, el significado del término “patrimonio” implica los recursos locales que se han asentado en el tiempo y que caracterizan el contexto patrimonial al que pertenecen: el histórico-arquitectónico, el artísticocultural y el paisajístico-ambiental. En un momento histórico de escasez de recursos, de creciente competición global y de problemas ambientales, cada vez, más graves los instrumentos de planificación urbana y territorial deben sostener primordialmente medidas en pos de la salvaguardia, valorización y reutilización del patrimonio existentes. Los grandes eventos podrían ser una oportunidad para implementar estas perspectivas.ABSTRACTIn the disciplinary field of urban and land planning, the meaning of the term “heritage”, refers to the local resources that remain through time which characterized the context that they belong to: heritage such as the historical and architectural, artistic and cultural and landscape and environmental. In a historical moment of scarcity of resources, increased global competition and environmental problems becoming more serious, the instruments of urban and land planning decisions should be held first measures towards the safeguard, value and reuse of existing assets. Great Events may be an opportunity to implement these perspectives
Digital services for an internet of places: urban digital nodes for a smart region between Milan and Turin
This paper presents the outcomes of a three-year research project developed by the Politecnico di Milano, Dipartimento di Architettura e Studi Urbani (DAStU), in collaboration with Telecom Italia. Looking at territorial smartness from a spatial perspective, that leaves aside the purely technological aspects, the research aims at exploring different ICT potentialities: from new uses of space, to socio-economic and physical regeneration. With this goal, it reflects about the possible updating of concepts, which are widely used in urban planning:
(i) from smart city to smart region, to deal with the regional scale of contemporary cities, thus including peripheral and marginal ‘in-between’ spaces;
(ii) from urban nodes to urban digital nodes, to design multi-scalar smart spaces able to integrate traditional and digital services;
(iii) from Internet of Things to Internet of Places, to make spaces able to interact through (at the same time) real and virtual experiences of users.
These theoretical references are explored within the scenario of the metropolitan region between Milan and Turin. According to these issues, this paper presents the research process to the UDN localization along the infrastructural bundle between Milan and Turin: from the identification of urban/infrastructural nodes, to the selection of potential Urban Digital Nodes. Furthermore, it highlights the UDN contribution to a smart region development through the spatial implementation of an Internet of Places
Deficit irrigation and maturation stage influence quality and flavonoid composition of ‘Valencia’ orange fruit
BACKGROUND:Effects of continuous deficit irrigation (DI) and partial rootzone drying (PRD) treatments (50%ETc) in comparison
with full irrigation (CI, 100% ETc) were investigated during ‘Valencia’ orange fruit maturation. Ultra-high-performance liquid
chromatography/high-resolutionmass spectrometry was used to quantify hesperidin, narirutin, tangeritin, nobiletin, didymin
and neoeriocitrin in the fruit juice and peel.
RESULTS: No significant effect of irrigation was found on yield, juice soluble solids or acidity. Juice color was not influenced
by irrigation or harvest date, whereas peel color increased during maturation and was more pronounced in CI and PRD fruits.
Juice acidity reached a peak in May, while soluble solids increased linearly throughout maturation. Hesperidin was the major
flavanone detected during maturation, with concentrations 200-fold higher in the fruit peel than in the juice. In the peel,
narirutin, didymin and neoeriocitrin decreased while hesperidin, nobiletin and tangeritin increased with maturation. Narirutin
synthesis in the orange fruit was insensitive to irrigation strategy. In fruit peels, PRD and DI induced the decline of hesperidin,
nobiletin and tangeritin only in June, whereas in the juice, deficit irrigation treatments induced an increase in hesperidin and
didymin.
CONCLUSION: These results suggest that deficit irrigation, in particular the conditions imposed with PRD, may cause a
significant accumulation shift of total flavonoids from the fruit peel into the juice, with a positive impact on juice quality and
nutritional value. Fruit compositional changes during maturation also suggest that late harvest can improve fruit palatability
and nutritional quality under the cultural and environmental conditions of this study
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