12,531 research outputs found
Combined Partial Wave Analysis for the description of exclusive production
The production of p K+ {\Lambda} in elementary p + p collision was
investigated using the Bonn Gatchina Partial Wave Analysis framework. This
approach allows the determination of possible participating production wave
depending on the quantum numbers of the system. For the analysis seven data
samples, measured at different detectors and beam energies, were used.For the
extraction of the p{\Lambda} scattering length a cross check with established
methods is required. Furthermore the total cross section of the production
process is needed to be determined to extra cross section for the separate
waves. Both methods are described in this work.Comment: 4 pages, 2 figure
Unexpected features of e+e-->ppbar and e+e-->lambda-lambdabar cross sections near threshold
Unexpected features of the BaBar data on e+e- in baryon-antibaryon cross
sections are discussed. These data have been collected, with unprecedented
accuracy, by means of the initial state radiation technique, which is
particularly suitable in giving good acceptance and energy resolution at
threshold. A striking feature observed in the BaBar data is the non-vanishing
cross section at threshold for all these processes. This is the expectation due
to the Coulomb enhancement factor acting on a charged fermion pair. In the case
of e+e- in proton-antiproton it is found that Coulomb final state interactions
largely dominate the cross section and the form factor is |G^p(4M^2_p)|~1,
which could be a general feature for baryons. In the case of neutral baryons an
interpretation of the non-vanishing cross section at threshold is suggested,
based on quark electromagnetic interaction and taking into account the
asymmetry between attractive and repulsive Coulomb factors. Besides strange
baryon cross sections are compared to U-spin invariance predictions.Comment: 12 pages, 11 figure
A defect in early myogenesis causes Otitis media in two mouse models of 22q11.2 Deletion Syndrome
Otitis media (OM), the inflammation of the middle ear, is the most common disease and cause for surgery in infants worldwide. Chronic Otitis media with effusion (OME) often leads to conductive hearing loss and is a common feature of a number of craniofacial syndromes, such as 22q11.2 Deletion Syndrome (22q11.2DS). OM is more common in children because the more horizontal position of the Eustachian tube (ET) in infants limits or delays clearance of middle ear effusions. Some mouse models with OM have shown alterations in the morphology and angle of the ET. Here, we present a novel mechanism in which OM is caused not by a defect in the ET itself but in the muscles that control its function. Our results show that in two mouse models of 22q11.2DS (Df1/+ and Tbx1(+/-)) presenting with bi- or unilateral OME, the fourth pharyngeal arch-derived levator veli palatini muscles were hypoplastic, which was associated with an earlier altered pattern of MyoD expression. Importantly, in mice with unilateral OME, the side with the inflammation was associated with significantly smaller muscles than the contralateral unaffected ear. Functional tests examining ET patency confirmed a reduced clearing ability in the heterozygous mice. Our findings are also of clinical relevance as targeting hypoplastic muscles might present a novel preventative measure for reducing the high rates of OM in 22q11.2DS patients
Increasing Performances of TCP Data Transfers Through Multiple Parallel Connections
Although Transmission Control Protocol (TCP) is a widely deployed and successful protocol, it shows some limitations in present-day environments. In particular, it is unable to exploit multiple (physical or logical) paths between two hosts. This paper presents PATTHEL, a session-layer solution designed for parallelizing stream data transfers. Parallelization is achieved by striping the data flow among multiple TCP channels. This solution does not require invasive changes to the networking stack and can be implemented entirely in user space. Moreover, it is flexible enough to suit several scenarios - e.g. it can be used to split a data transfer among multiple relays within a peer-to-peer overlay networ
Putting the self into perspective: Fiction and moral imagination in Giovanni Verga
In this article, I argue that we should avoid a moralist interpretation of Verga and his Verist works. The literary value of Verga's Verist works consists neither in the expression of a nostalgia for the good life within a traditional community, nor in a defiant attitude towards a nihilist modernity. This is better shown by a careful reading of Fantasticheria, which I claim is the key text for understanding both Verga's career as a writer, and his novel I Malavoglia (1881). Fantasticheria is both a form of self-writing, whereby Verga stages himself as a modernist writer, and a metanarrative and meta-fictional commentary, which elaborates on a theory of literary fiction. According to Verga, writing and reading fiction is an exercise in moral imagination; it is a way of imagining life from the others’ point of view, and putting one's own sense of oneself into perspective
Il Gattopardo di Lampedusa come saga familiare: realismo modernista ed erosione dell’orizzonte della famiglia patriarcale
In questo saggio l'autore sostiene che la lettura tuttora diffusa del Gattopardo come un romanzo storico scritto da un conservatore non è accettabile. Il Gattopardo va invece interpretato come una saga familiare che racconta uno dei cambiamenti più radicali della società moderna: l’erosione dell’orizzonte di senso della famiglia patriarcale. Per sostenere questa interpretazione del Gattopardo l'autore riconsidera anzitutto le scelte di vita di Lampedusa e la sua concezione della politica. Poi commenta le sue riflessioni sulla letteratura e mostra come sia la stesura dei Ricordi a convincerlo a scrivere una saga familiare. Il saggio si chiude con un’analisi del Gattopardo, dove si mostra come sia il suo stile narrativo, che l'autore chiama “realismo modernista”, a condurre lettrici e lettori a immaginare dall’interno la scomparsa dell’orizzonte della famiglia patriarcale
Kaon production and propagation at intermediate relativistic energies
We systematically study observables in nucleus-nucleus collisions at
1-2 A GeV within the Boltzmann-Uehling-Uhlenbeck (BUU) transport model. We
compare our calculations with the KaoS data on the kaon multiplicities and
spectra. In addition, the kaon collective flow is computed and compared with
the FOPI and KaoS data. We show, that the elliptic kaon flow measured recently
by the KaoS Collaboration is best described by using the Brown-Rho
parametrization of the kaon potential ( MeV).Comment: 21 pages, 3 tables, 17 figures; references added; version accepted in
PR
Raccontare l’Italia plurale: “questione meridionale” e immaginario morale nel Verga verista
In questo saggio sostengo che il Verga verista racconti il paesaggio morale dell’Italia moderna. Attraverso la lettura di passi tratti dai testi dei primi meridionalisti e di Pitrè e passi tratti dalla Prefazione a "I Malavoglia" e da "Fantasticheria", mostro come il Verga verista abbandoni l’immaginario morale del nazionalismo romantico, per dare forma alla sua immaginazione liberale e al suo realismo morale, grazie ai quali può raccontare dall’interno una pluralità di orizzonti di senso divergenti ed eterogenei
Sum rule for a difference of proton and neutron total photoproduction cross-sections
Starting from very high energy inelastic electron-nucleon scattering with a
production of a hadronic state to be moved closely to the direction of the
initial nucleon, then utilizing analytic properties of parts of forward virtual
Compton scattering amplitudes on proton and neutron, one obtains the relation
between nucleon form factors and a difference of proton and neutron
differential electroproduction cross-sections. In particular, for the case of
small transferred momenta, one finally derives sum rule, relating Dirac proton
mean square radius and anomalous magnetic moments of proton and neutron to the
integral over a difference of the total proton and neutron photoproduction
cross-sections.Comment: LaTeX2e, 7 pages, 1 eps figure (revised version
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