arXiv subjects

L. Labarga

Publications and source records attributed to L. Labarga.

132 records · Page 8Linked to original sources

arXiv2012

SiPMs coated with TPB : coating protocol and characterization for NEXT

Silicon photomultipliers (SiPM) are the photon detectors chosen for the tracking readout in NEXT, a neutrinoless ββ decay experiment which uses a high pressure gaseous xenon time projection chamber (TPC). The reconstruction of event track and topology in this gaseous detector is a key handle for background rejection. Among the commercially available sensors that can be used for tracking, SiPMs offer important advantages, mainly high gain, ruggedness, cost-effectiveness and radio-purity. Their main drawback, however, is their non sensitivity in the emission spectrum of the xenon scintillation (peak at 175 nm). This is overcome by coating these sensors with the organic wavelength shifter tetraphenyl butadienne (TPB). In this paper we describe the protocol developed for coating the SiPMs with TPB and the measurements performed for characterizing the coatings as well as the performance of the coated sensors in the UV-VUV range.

physics.ins-det↗

arXiv2011

Supernova Relic Neutrino Search at Super-Kamiokande

A new Super-Kamiokande (SK) search for Supernova Relic Neutrinos (SRNs) was conducted using 2853 live days of data. Sensitivity is now greatly improved compared to the 2003 SK result, which placed a flux limit near many theoretical predictions. This more detailed analysis includes a variety of improvements such as increased efficiency, a lower energy threshold, and an expanded data set. New combined upper limits on SRN flux are between 2.8 and 3.0 nu_e cm^-2 s^-1 > 16 MeV total positron energy (17.3 MeV E_nu).

hep-ex↗

arXiv2011

Search for Differences in Oscillation Parameters for Atmospheric Neutrinos and Antineutrinos at Super-Kamiokande

We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande -I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best fit antineutrino mixing is found to be at (dm2bar, sin2 2 thetabar) = (2.0x10^-3 eV^2, 1.0) and is consistent with the overall Super-K measurement.

hep-ex↗

arXiv2009

The LAGUNA design study- towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are being studied: Boulby (UK), Canfranc (Spain), Fréjus (France/Italy), Pyhäsalmi (Finland), Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The design study aims at the comprehensive and coordinated technical assessment of each site, at a coherent cost estimation, and at a prioritization of the sites within the summer 2010.

physics.ins-det↗

arXiv2007

Response Uniformity of the ATLAS Liquid Argon Electromagnetic Calorimeter

The construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize the complete energy reconstruction chain from the readout and calibration electronics to the signal and energy reconstruction. It was also possible to check the full Monte Carlo simulation of the calorimeter. The analysis of the uniformity, resolution and extraction of constant term is presented. Typical non-uniformities of 0.5% and typical global constant terms of 0.6% are measured for the barrel and end-cap modules.

physics.ins-det↗

arXiv1996

Pomerons and Jet Events at HERA

We study two and three jet events with a large rapidity gap at HERA. Unlike in the Ingelman-Schlein approach we do not adscribe a structure to the Pomeron. Instead, the coupling of the Pomeron to quarks or gluons is taken pointlike, which makes the model easy to test: the only degrees of freedom are the coupling constants of the Pomeron to the quarks or the gluons and a cutoff procedure to keep the Pomeron-gluon coupling well behaved.

hep-ph↗