Theoretical Aspects of Higgs Physics at the LHC

The strategies recently developed to study Higgs boson properties at the LHC are reviewed. It is shown how to obtain model-independent determinations of couplings to fermions and gauge bosons by exploiting different production and decay channels. We consider the case of Weak Boson Fusion Higgs production with H decaying into b anti-bComment: 4 pages, 1 figure. EPSHEP Conference Proceedings, Aachen 200

O'Mega: An Optimizing Matrix Element Generator

We sketch the architecture of O'Mega, a new optimizing compiler for tree amplitudes in quantum field theory, and briefly describe its usage. O'Mega generates the most efficient code currently available for scattering amplitudes for many polarized particles in the Standard Model and its extensions.Comment: 29 pages, LaTe

Electroweak Sudakov Corrections to New Physics Searches at the CERN LHC

We compute the one-loop electroweak Sudakov corrections to the production process Z (nu bar{nu}) + n jets, with n = 1,2,3, in p p collisions at the LHC. It represents the main irreducible background to new physics searches at the energy frontier. The results are obtained at the leading and next-to-leading logarithmic accuracy by implementing the general algorithm of Denner-Pozzorini in the event generator for multiparton processes ALPGEN. For the standard selection cuts used by ATLAS and CMS collaborations, we show that the Sudakov corrections to the relevant observables can grow up to - 40% at sqrt{s} = 14 TeV. We also include the contribution due to undetected real radiation of massive gauge bosons, to show to what extent the partial cancellation with the large negative virtual corrections takes place in realistic event selections.Comment: 5 pages, 3 figures, 1 table. Extended discussion on real radiation processes. Added references. Results unchanged. Version to appear in Phys. Rev. Let

The Scuola Normale Superiore of Pisa. Between the French model and autonomous choices (1810-1923)

Der Beitrag konzentriert sich auf das französische Modell am Beispiel der Geschichte der Scuola Normale Superiore in Pisa, die 1810 von Napoleon auf der Asche der Erfahrungen des Jahres III der Revolution (1795) gegründet wurde, die 1813 faktisch eröffnet und 1847 von Habsburg-Lothringen wiedereröffnet wurde, bevor sie 1862 von der italienischen Regierung reorganisiert wurde. Im Fall der Scuola Normale Superiore werden alte und neue Bildungsphänomene (man denke an die Realität des Internats, das Erbe der religiösen Lehrorden, das lange Zeit nicht nur in Bezug auf Frankreich, sondern z.B. auch auf England diskutiert wurde) in den Blickpunkt der Gesetzgeber/innen und der Forscher/innen gerückt. Frankreich und Deutschland bleiben lange die zentralen Bezugspunkte in Italien für den sekundären schulischen und den universitären Bereich. (DIPF/Orig.

Higgs Boson Production in Association with a Photon in Vector Boson Fusion at the LHC

Higgs boson production in association with two forward jets and a central photon at the CERN Large Hadron Collider is analyzed, for the Higgs boson decaying into a b bbar pair in the m_H <= 140 GeV mass region. We study both irreducible and main reducible backgrounds at parton level. Compared to the Higgs production via vector-boson fusion, the request of a further photon at moderate rapidities dramatically enhances the signal/background ratio. Inclusive cross sections for p_T^\gamma >= 20 GeV can reach a few tens of fb's. After a suitable choice of kinematical cuts, the cross-section ratio for signal and irreducible-background can be enhanced up to >= ~1/10, with a signal cross section of the order of a few fb's, for m_H ~ 120 GeV. The request of a central photon radiation also enhances the relative signal sensitivity to the WWH coupling with respect to the ZZH coupling. Hence, a determination of the cross section for the associated production of a Higgs boson decaying into a b bbar pair plus a central photon in vector-boson fusion could help in constraining the b bbar H coupling, and the WWH coupling as well. A preliminary study of QCD showering effects points to a further significant improvement of the signal detectability over the background.Comment: 30 pages, 8 figures, 8 tables; minor corrections to the text; version appeared in Nuclear Physics

«Quando in cospetto a l’aquila». Sul Medioevo carducciano

«V’imaginate il levar del sole nel primo giorno dell’anno Mille?». La citazione è in fondo scontata, ed il brano è notissimo; ma l’esordio dei discorsi Dello svolgimento della letteratura nazionale fissava con straordinaria efficacia alcune delle coordinate del complesso discorso carducciano attorno al medioevo – e sarebbe preferibile, del resto, usare al plurale la determinazione epocale, parlando, per Carducci, di diversi tempi, luoghi e volti del medioevo. Le profezie più antiche e più recenti, formulate queste in anni di «disperate ruine», non si erano compiute:Mille, e non più mille – aveva, secondo la tradizione, detto Gesù: dopo mille anni, leggevasi nell’Apocalipsi, Satana sarà disciolto. Di fatto nelle nefandezze del secolo decimo, in quello sfracellarsi della monarchia e della società dei conquistatori nelle infinite unità feudali, in quell’abiettarsi ineffabile del ponteficato cristiano, in quelle scorrerie procellose di barbari nuovi ed orribili, non era egli lecito riconoscere i segni descritti dal veggente di Patmo? Il sole, invece, si era ancora alzato sull’«Italia romana» mortificata e devastata dalle «idee degli ascetici» e dalla «violenza dei barbari» – e la terminologia carducciana è rivelatrice di contatti non occasionali, meditati, con uno dei grandi filoni di indagine storica e di rievocazione letteraria che caratterizzarono l’ottocentesca ricostruzione della légende des siècles europea –:Il sole! V’è dunque ancora una patria? e v’è il mondo? E l’Italia distendeva le membra raggricciate dal gelo della notte, e toglieasi d’intorno al capo il velo dell’ascetismo per guardare all’oriente. Di fatti sin nei primi anni del secolo undecimo sentesi come un brulicare di vita ancor timida e occulta, che poi scoppierà in lampi e tuoni di pensieri e di opere: di qui veramente incomincia la storia del popolo italiano

Convergence of Neural Networks with a Class of Real Memristors with Rectifying Characteristics

The paper considers a neural network with a class of real extended memristors obtained via the parallel connection of an ideal memristor and a nonlinear resistor. The resistor has the same rectifying characteristic for the current as that used in relevant models in the literature to account for diode-like effects at the interface between the memristor metal and insulating material. The paper proves some fundamental results on the trajectory convergence of this class of real memristor neural networks under the assumption that the interconnection matrix satisfies some symmetry conditions. First of all, the paper shows that, while in the case of neural networks with ideal memristors, it is possible to explicitly find functions of the state variables that are invariants of motions, the same functions can be used as Lyapunov functions that decrease along the trajectories in the case of real memristors with rectifying characteristics. This fundamental property is then used to study convergence by means of a reduction-of-order technique in combination with a Lyapunov approach. The theoretical predictions are verified via numerical simulations, and the convergence results are illustrated via the applications of real memristor neural networks to the solution of some image processing tasks in real time

Complete Stability of Neural Networks With Extended Memristors

The article considers a large class of delayed neural networks (NNs) with extended memristors obeying the Stanford model. This is a widely used and popular model that accurately describes the switching dynamics of real nonvolatile memristor devices implemented in nanotechnology. The article studies via the Lyapunov method complete stability (CS), i.e., convergence of trajectories in the presence of multiple equilibrium points (EPs), for delayed NNs with Stanford memristors. The obtained conditions for CS are robust with respect to variations of the interconnections and they hold for any value of the concentrated delay. Moreover, they can be checked either numerically, via a linear matrix inequality (LMI), or analytically, via the concept of Lyapunov diagonally stable (LDS) matrices. The conditions ensure that at the end of the transient capacitor voltages and NN power vanish. In turn, this leads to advantages in terms of power consumption. This notwithstanding, the nonvolatile memristors can retain the result of computation in accordance with the in-memory computing principle. The results are verified and illustrated via numerical simulations. From a methodological viewpoint, the article faces new challenges to prove CS since due to the presence of nonvolatile memristors the NNs possess a continuum of nonisolated EPs. Also, for physical reasons, the memristor state variables are constrained to lie in some given intervals so that the dynamics of the NNs need to be modeled via a class of differential inclusions named differential variational inequalities

Laboratory and on-site tests for rapid runway repair

The attention to rapid pavement repair has grown fast in recent decades: this topic is strategic for the airport management process for civil purposes and peacekeeping missions. This work presents the results of laboratory and on-site tests for rapid runway repair, in order to analyse and compare technical and mechanical performances of 12 different materials currently used in airport. The study focuses on site repairs, a technique adopted most frequently than repairs with modular elements. After describing mechanical and physical properties of the examined materials (2 bituminous emulsions, 5 cement mortars, 4 cold bituminous mixtures and 1 expanding resin), the study presents the results of carried out mechanical tests. The results demonstrate that the best performing material is a one-component fast setting and hardening cement mortar with graded aggregates. This material allows the runway reopening 6 h after the work. A cold bituminous mixture (bicomponent premixed cold asphalt with water as catalyst) and the ordinary cement concrete allow the reopening to traffic after 18 h, but both ensure a lower service life (1000 coverages) than the cement mortar (10,000 coverages). The obtained results include important information both laboratory level and field, and they could be used by airport management bodies and road agencies when scheduling and evaluating pavement repairs

The Swift X-ray Telescope Cluster Survey III: Cluster Catalog from 2005-2012 Archival Data

We present the Swift X-ray Cluster Survey (SWXCS) catalog obtained using archival data from the X-ray telescope (XRT) on board the Swift satellite acquired from 2005 to 2012, extending the first release of the SWXCS. The catalog provides positions, soft fluxes, and, when possible, optical counterparts for a flux-limited sample of X-ray group and cluster candidates. We consider the fields with Galactic latitude |b| > 20 degree to avoid high HI column densities. We discard all of the observations targeted at groups or clusters of galaxies, as well as particular extragalactic fields not suitable to search for faint extended sources. We finally select ~3000 useful fields covering a total solid angle of ~400 degree^2. We identify extended source candidates in the soft-band (0.5-2keV) images of these fields using the software EXSdetect, which is specifically calibrated for the XRT data. Extensive simulations are used to evaluate contamination and completeness as a function of the source signal, allowing us to minimize the number of spurious detections and to robustly assess the selection function. Our catalog includes 263 candidate galaxy clusters and groups down to a flux limit of 7E-15 erg/cm^2/s in the soft band, and the logN-logS is in very good agreement with previous deep X-ray surveys. The final list of sources is cross-correlated with published optical, X-ray, and SZ catalogs of clusters. We find that 137 sources have been previously identified as clusters, while 126 are new detections. Currently, we have collected redshift information for 158 sources (60% of the entire sample). Once the optical follow-up and the X-ray spectral analysis of the sources are complete, the SWXCS will provide a large and well-defined catalog of groups and clusters of galaxies to perform statistical studies of cluster properties and tests of cosmological models.Comment: 41 pages, 16 figures, 3 tables, published on ApJS in Jan 201