The OPERA magnetic spectrometer

The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.Comment: 6 pages, 10 figures, presented at the 2003 IEEE-NSS conference, Portland, OR, USA, October 20-24, 200

The ZEUS Micro Vertex Detector

During the HERA luminosity shutdown period 2000/01 the tracking system of the ZEUS experiment has been upgraded with a silicon Micro Vertex Detector (MVD). The barrel part of the detector consists of three layers of single sided silicon strip detectors, while the forward section is composed of four wheels. In this report we shortly present the assembly procedure and in more details the test beam results on the spatial resolution of half modules. The first results of a cosmic ray test are presented and the radiation monitor system is described.Comment: 8 pages, 5 figures, Talk presented at the VERTEX 2001 Workshop, 23-28 Sept. 2001, Brunnen, Switzerland. Submitted to Nucl. Instr. and Meth.

'Oltre l'Australia c'è la luna': Maggio garfagnino and the Emigrant Experience

When I first visited the Garfagnana region of north-western Tuscany in 1991, I was assured by functionaries from the provincial government that the Maggio tradition of sung popular theatre would be finished within five years. The singers were too old, the tourists weren’t interested, there were no young people to carry it on. Yet over the next five years of my increasing involvement in the tradition, I saw a growth in the numbers of performances, active performers and companies, and audience numbers. This chapter advances some thoughts as to why Maggio continued so strongly against the odds in its home region of the Garfagnana, while attempts to mount performances in Australia have (to my knowledge) so far failed, despite the considerable numbers of Garfagnini who emigrated there. I will argue that the strength of the nexus between paese (home town) and performance practice in the Garfagnino Maggio stems from the Garfagnana’s long history of emigration, and that indeed various features of the Maggio genre appear to result from, or at least be intensified by, a “diaspora effect”, that is, the effect of expatriates on their community of origin. I argue that to understand the themes, form, performance practice and survival of this most localised of traditions we need to take into account the transnationalism of many Garfagnini and the role of campanilismo (loyalty to one’s home village) in sustaining emigrants abroad.Australian Research Counci

Two-body Photodisintegration of 4^{4}He with Full Final State Interaction

The cross sections of the processes $^4$He($\gamma,p$)$^3$H and $^4$He($\gamma,n$)$^3$He are calculated taking into account the full final state interaction via the Lorentz integral transform (LIT) method. This is the first consistent microscopic calculation beyond the three--body breakup threshold. The results are obtained with a semirealistic central NN potential including also the Coulomb force. The cross sections show a pronounced dipole peak at 27 MeV which lies within the rather broad experimental band. At higher energies, where experimental uncertainties are considerably smaller, one finds a good agreement between theory and experiment. The calculated sum of three-- and four--body photodisintegration cross sections is also listed and is in fair agreement with the data.Comment: 18 pages, 6 figure

Design and Tests of the Silicon Sensors for the ZEUS Micro Vertex Detector

To fully exploit the HERA-II upgrade,the ZEUS experiment has installed a Micro Vertex Detector (MVD) using n-type, single-sided, silicon micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 micrometers, with five intermediate strips (20 micrometer strip pitch). The designs of the silicon sensors and of the test structures used to verify the technological parameters, are presented. Results on the electrical measurements are discussed. A total of 1123 sensors with three different geometries have been produced by Hamamatsu Photonics K.K. Irradiation tests with reactor neutrons and Co-60 photons have been performed for a small sample of sensors. The results on neutron irradiation (with a fluence of 1 x 10^{13} 1 MeV equivalent neutrons / cm^2) are well described by empirical formulae for bulk damage. The Co-60 photons (with doses up to 2.9 kGy) show the presence of generation currents in the SiO_2-Si interface, a large shift of the flatband voltage and a decrease of the hole mobility.Comment: 33 pages, 25 figures, 3 tables, accepted for publication in NIM

Beam Test of Silicon Strip Sensors for the ZEUS Micro Vertex Detector

For the HERA upgrade, the ZEUS experiment has designed and installed a high precision Micro Vertex Detector (MVD) using single sided micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 microns, with five intermediate strips (20 micron strip pitch). An extensive test program has been carried out at the DESY-II testbeam facility. In this paper we describe the setup developed to test the ZEUS MVD sensors and the results obtained on both irradiated and non-irradiated single sided micro-strip detectors with rectangular and trapezoidal geometries. The performances of the sensors coupled to the readout electronics (HELIX chip, version 2.2) have been studied in detail, achieving a good description by a Monte Carlo simulation. Measurements of the position resolution as a function of the angle of incidence are presented, focusing in particular on the comparison between standard and newly developed reconstruction algorithms.Comment: 41 pages, 21 figures, 2 tables, accepted for publication in NIM

On the muon neutrino mass

During the runs of the PS 179 experiment at LEAR of CERN, we photographed an event of antiproton-Ne absorption, with a complete pi+ -> mu+ ->e+ chain. From the vertex of the reaction a very slow energy pi+ was emitted. The pi+ decays into a mu+ and subsequently the mu+ decays into a positron. At the first decay vertex a muon neutrino was emitted and at the second decay vertex an electron neutrino and a muon antineutrino. Measuring the pion and muon tracks and applying the momentum and energy conservation and using a classical statistical interval estimator, we obtained an experimental upper limit for the muon neutrino mass: m_nu < 2.2 MeV at a 90% confidence level. A statistical analysis has been performed of the factors contributing to the square value of the neutrino mass limit.Comment: 18 pages, 5 eps figure

Florencia en el "desierto de las tribulaciones". Nota sobre Jerónimo Savonarola, profeta del bien común histórico

El artículo examina las características de la predicación que el fraile dominicano Jerónimo Savonarola (1452-1498) desarrolla en Florencia en sus tres últimos años y medio de vida. En dicho periodo, iniciado con la fuga del tirano Piero de Médicis, intentThe article examines the preaching features of the Dominican Friar Girolamo Savonarola (1452-1498) in Florence in the last 3? years of his life, after the escape of the tyrant Piero de Medici. During that period, he demonstrates to be able to direct the

The GERDA experiment at Gran Sasso: Search for neutrinoless double beta decay in germanium 76

The GERmanium Detector Array (GERDA) is a low background experiment at the Laboratori Nazionali del Gran Sasso (LNGS) designed to search for the rare neutrinoless double beta decay (0νββ) of 76Ge. In the first phase of the experiment, high purity germanium diodes inherited from the former Heidelberg-Moscow and IGEX experiments are operated “bare” and immersed in liquid argon, with an overall background environment of 2 · 10−2 cts/(keVkg yr), a factor of ten better than its predecessors. Preliminary measurements on two neutrinos double beta decay (2νββ) giving T2ν 1/2 = (1.88 ± 0.10) · 1021 yr and a recently published background model are discussed in the paper. Results on 0νββ are expected in summer 2013 and, in the absence of a signal, the expected sensitivity is T0ν 1/2 > 1.9 × 1025 yr. Phase II of the experiment is scheduled to start at the end of 2013, after an upgrade shutdown, with an additional set of new detectors. Thanks to the new design of the diodes and to the introduction of liquid argon instrumentation techniques, the experiment aims to reduce further the expected background to about 1 · 10−3 cts/(keVkg yr), and improve the 0νββ sensitivity to T0ν 1/2 > 1.35 · 1026 yr