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

A compact light readout system for longitudinally segmented shashlik calorimeters

The longitudinal segmentation of shashlik calorimeters is challenged by dead zones and non-uniformities introduced by the light collection and readout system. This limitation can be overcome by direct fiber-photosensor coupling, avoiding routing and bundling of the wavelength shifter fibers and embedding ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present the first experimental test of this readout scheme performed at the CERN PS-T9 beamline in 2015 with negative particles in the 1-5~GeV energy range. In this paper, we demonstrate that the scheme does not compromise the energy resolution and linearity compared with standard light collection and readout systems. In addition, we study the performance of the calorimeter for partially contained charged hadrons to assess the $e/\pi$ separation capability and the response of the photosensors to direct ionization.Comment: To appear in Nuclear Instruments and Methods in Physics Research,

Survival and reoperation in acute aortic syndromes - a single-centre experience of 912 patients

OBJECTIVES: Acute aortic syndromes are associated with poor outcomes, despite diagnostic and therapeutic advances. We analysed trends in volumes and outcomes from 2000 to 2021. METHODS: The study population includes 494 type A acute aortic syndromes (TAAAS) (54.2%) and 418 type B acute aortic syndromes (TBAAS) (45.8%). Primary outcomes were in-hospital mortality, long-term survival and freedom from aortic reoperation. RESULTS: Regardless the type of acute aortic syndrome, patient volumes increased over time. Patients with TBAAS were older, more likely to have comorbid conditions and previous cardiac surgery (P < 0.001), while cerebrovascular accidents were more frequent in TAAAS (P < 0.05). Among TAAAS, 143 (28.9%) required total arch and 351 (71.1%) hemiarch replacement. TBAAS management was medical therapy in 182 (43.5%), endovascular in 198 (47.4%) and surgical in 38 (9.1%) cases. Overall in-hospital mortality was 14.6% [18.2% in TAAAS (95% confidence interval (CI) 14.4-21.2%) vs 10.7% in TBAAS (95% CI 7.8%-13.7%); P = 0.0027]. After propensity score adjustment, in-hospital mortality exhibited a significantly decreasing trend from 2000 to 2021 (P < 0.001) in TAAAS and TBAAS. 1-, 5- and 10-year survival was 74.2%, 62.2% and 45.5% in TAAAS and 75.4%, 60.7% and 41.0% in TBAAS (P = 0.975), with no differences among treatment strategies. The adjusted cumulative reoperation risk at 10 years was more than two-fold in TBAAS versus TAAAS (9.5% vs 20.5%, hazard ratio (HR) = 2.30, 95% I 1.31-4.04). CONCLUSIONS: In the last decades, better patient triage and surgical/endovascular techniques led to substantial improvements in the management of acute aortic syndrome, with reduction in early mortality and reoperation rate. However, long-term mortality is still >50%

Pregnancy outcome after loop electrosurgical excision procedure for cervical intraepithelial neoplasia

To determine pregnancy outcomes among women who underwent loop electrosurgical excision procedure (LEEP)

Initial operation of the International Gravitational Event Collaboration

The International Gravitational Event Collaboration, IGEC, is a coordinated effort by research groups operating gravitational wave detectors working towards the detection of millisecond bursts of gravitational waves. Here we report on the current IGEC resonant bar observatory, its data analysis procedures, the main properties of the first exchanged data set. Even though the available data set is not complete, in the years 1997 and 1998 up to four detectors were operating simultaneously. Preliminary results are mentioned.Comment: 8 pages, 2 figures, 3 tables; Proceeding of the GWDAW'99. Submitted to the International Journal of Modern Physic

On-line recognition of supernova neutrino bursts in the LVD detector

In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated to a supernova explosion, in the absence of an "external trigger", e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and electron anti-neutrino intensity at the source.Comment: Accepted for pubblication on Astroparticle Physics. 13 pages, 10 figure

First CNGS events detected by LVD

The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band $\nu_{\mu}$ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the $\nu_{\tau}$ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of $7.6~10^{17}$ protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.Comment: Accepted for publication by the European Physical Journal C ; 7 pages, 11 figure

New Eco-gas mixtures for the Extreme Energy Events MRPCs: results and plans

The Extreme Energy Events observatory is an extended muon telescope array, covering more than 10 degrees both in latitude and longitude. Its 59 muon telescopes are equipped with tracking detectors based on Multigap Resistive Plate Chamber technology with time resolution of the order of a few hundred picoseconds. The recent restrictions on greenhouse gases demand studies for new gas mixtures in compliance with the relative requirements. Tetrafluoropropene is one of the candidates for tetrafluoroethane substitution, since it is characterized by a Global Warming Power around 300 times lower than the gas mixtures used up to now. Several mixtures have been tested, measuring efficiency curves, charge distributions, streamer fractions and time resolutions. Results are presented for the whole set of mixtures and operating conditions, %. A set of tests on a real EEE telescope, with cosmic muons, are being performed at the CERN-01 EEE telescope. The tests are focusing on identifying a mixture with good performance at the low rates typical of an EEE telescope.Comment: 8 pages, 6 figures, proceedings for the "XIV Workshop on Resistive Plate Chambers and Related Detectors" (19-23 February 2018), Puerto Vallarta, Jalisco State, Mexic