Search results for " Anni"
showing 10 items of 847 documents
A bounded version of bosonic creation and annihilation operators and their related quasi-coherent states
2007
Coherent states are usually defined as eigenstates of an unbounded operator, the so-called annihilation operator. We propose here possible constructions of {\em quasi-coherent states}, which turn out to be {\em quasi} eigenstate of a \underline{bounded} operator related to an annihilation-like operator. We use this bounded operator to construct a sort of modified harmonic oscillator and we analyze the dynamics of this oscillator from an algebraic point of view.
“UTILE E NECESSARIO PAREVA E PARE IL ROMANZO”: LA RICERCA DI UNA NUOVA PROSA NELLA RUSSIA DEGLI ANNI VENTI
2007
An introduction to a collection of articles on the Soviet novel of the Twenties, outlining the situation of prose writing at the time, caught between the heritage of the avant-garde and the requirements of the authorities.
Structural-relaxation phenomena in As–S glasses as probed by combined PAL/DBAR technique
2015
Abstract Experimental techniques exploring phenomena of positron–electron interaction, namely the positron annihilation lifetime spectroscopy and Doppler broadening of annihilation radiation, are shown to be very informative tools to study radiation- and thermally-induced phenomena in chalcogenide glasses of binary As–S system. Time-dependent processes of free-volume voids agglomeration (expansion), fragmentation (refining) and disappearing (contraction) are identified as main stages of physical aging in S-rich glasses, while a competitive channel of coordination topological defects formation associated with void charging becomes significant in a vicinity of near-stoichiometric glass compos…
Äänekosken Naiskuoro 1941-2005
2005
Anomalous quartic gauge boson couplings at hadron colliders
2000
We analyze the potential of the Fermilab Tevatron and CERN Large Hadron Collider (LHC) to study anomalous quartic vector--boson interactions (photon photon Z Z) and (photon photon W+ W-). Working in the framework of SU(2)_L X U(1)_Y chiral Lagrangians, we study the production of photons pairs accompanied by (e+e-), (e nu), and jet pairs to impose bounds on these new couplings, taking into account the unitarity constraints. We compare our findings with the indirect limits coming from precision electroweak measurements as well as with presently available direct searches at LEPII. We show that the Tevatron Run II can provide limits on these quartic limits which are of the same order of magnitu…
Searches for heavy neutrinos from Z decays
1992
We have searched for possible fourth family heavy neutrinos, pair produced in Z0 decays, in a sample of about 112 000 hadronic Z0 final states collected with the DELPHI detector. For all mixing matrix elements we exclude a new Dirac neutrino lighter than 44.5 GeV at a 95% confidence level, if the neutrino couples to the electron or muon family, and lighter than 44.0 GeV, if the neutrino couples to the tau family. Depending on the values of the mixing element and to which lepton family the neutrino couples, we obtain mass limits up to 46.2 GeV. For all mixing matrix elements we exclude a new Majorana neutrino lighter than 39.0 GeV, if it couples to the electron or the muon family, and lighte…
Verso un curricolo 0-6: continuità, discontinuità e prospettive possibili a partire da un percorso di ricerca-azione nella città di Palermo
2021
A partire da una ricerca sulla costruzione di un possibile curricolo zero-sei, condotta con un gruppo di insegnanti di scuola dell’infanzia statale ed un gruppo di educatrici di un nido comunale operanti nello stesso territorio (un quartiere del centro storico di Palermo), l’articolo mira a mettere in luce e a problematizzare ambiti di continuità e di discontinuità tra i due servizi educativi collegandoli alla storia e alla cultura organizzativa dei servizi stessi. Intende, inoltre, riflettere su possibili proposte di cambiamento organizzativo nella direzione della continuità, attraverso l’adozione di una metodologia partecipativa centrata sulla autovalutazione riflessiva, sulla progettazio…
New high-sensitivity searches for neutrons converting into antineutrons and/or sterile neutrons at the HIBEAM/NNBAR experiment at the European Spalla…
2021
Abstract The violation of baryon number, B , is an essential ingredient for the preferential creation of matter over antimatter needed to account for the observed baryon asymmetry in the Universe. However, such a process has yet to be experimentally observed. The HIBEAM/NNBAR program is a proposed two-stage experiment at the European Spallation Source to search for baryon number violation. The program will include high-sensitivity searches for processes that violate baryon number by one or two units: free neutron–antineutron oscillation ( n → n ̄ ) via mixing, neutron–antineutron oscillation via regeneration from a sterile neutron state ( n → [ n ′ , n ̄ ′ ] → n ̄ ), and neutron disappearan…
L’educazione familiare e il consumo del cinema negli anni Cinquanta tra Nord e Sud d’Italia
2017
In questo articolo, il cinema degli anni Cinquanta viene indagato come mezzo di consumo e come strumento di socializzazione delle masse italiane, in un confronto tra il Nord industrializzato e il Sud ancora prevalentemente agricolo, ma anche tra le zone urbane e quelle rurali, tra classi e tra generi differenti. Seguendo la storia del cinema italiano nel «decennio più lungo del secolo breve», dal neorealismo al melò alla commedia, emerge che il cinema entrava nella vita delle famiglie italiane plasmandole, ridisegnando identità e costruendo nuovi immaginari. Nonostante il diverso approccio con cui le famiglie italiane andavano al cinema, questo fu vissuto come una fonte di istruzione che co…
AMBIENTE COSTRUITO E SOSTENIBILITÀ – Materiali riciclati e Design for Disassembly tra ricerca e buone pratiche
2020
In the context of environmental emergency of which the construction sector is one of the main causes – since it consumes 40% of the (embodied and operational) energy and produces about a third of the total waste – and due to the ambitious objectives set by the international community and by many countries to reduce the environmental impact of buildings during their whole life cycle, this paper wants to make a contribution to the understanding of the state of the art on cycle-based research activities, sustainable experiments and good practices that the building industry and the academy have implemented in recent years. In particular, it refers to cycle-based theoretical and experimental act…