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NEXT Collaboration(Alvarez, V. et al), Carcel, S., Cervera-Villanueva, A., Diaz, J., Ferrario, P., Gil, A., et al. (2013). Near-intrinsic energy resolution for 30-662 keV gamma rays in a high pressure xenon electroluminescent TPC. Nucl. Instrum. Methods Phys. Res. A, 708, 101–114.
Abstract: We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 Xe-136 neutrino-less double beta decay (0 nu beta beta) experiment with the main objectives of demonstrating near-intrinsic energy resolution at energies up to 662 keV and of optimizing the NEXT-100 detector design and operating parameters. Energy resolutions of similar to 1% FWHM for 662 keV gamma rays were obtained at 10 and 15 atm and similar to 5% FWHM for 30 keV fluorescence xenon X-rays. These results demonstrate that 0.5% FWHM resolutions for the 2459 keV hypothetical neutrino-less double beta decay peak are realizable. This energy resolution is a factor 7-20 better than that of the current leading 0 nu beta beta experiments using liquid xenon and thus represents a significant advancement. We present also first results from a track imaging system consisting of 64 silicon photo-multipliers recently installed in NEXT-DBDM that, along with the excellent energy resolution, demonstrates the key functionalities required for the NEXT-100 0 nu beta beta search.
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ANTARES Collaboration(Adrian-Martinez, S. et al), Barrios-Marti, J., Hernandez-Rey, J. J., Lambard, G., Mangano, S., Sanchez-Losa, A., et al. (2015). Search for muon-neutrino emission from GeV and TeV gamma-ray flaring blazars using five years of data of the ANTARES telescope. J. Cosmol. Astropart. Phys., 12(12), 014–27pp.
Abstract: The ANTARES telescope is well-suited for detecting astrophysical transient neutrino sources as it can observe a full hemisphere of the sky at all times with a high duty cycle. The background due to atmospheric particles can be drastically reduced, and the point-source sensitivity improved, by selecting a narrow time window around possible neutrino production periods. Blazars, being radio-loud active galactic nuclei with their jets pointing almost directly towards the observer, are particularly attractive potential neutrino point sources, since they are among the most likely sources of the very high-energy cosmic rays. Neutrinos and gamma rays may be produced in hadronic interactions with the surrounding medium. Moreover, blazars generally show high time variability in their light curves at different wavelengths and on various time scales. This paper presents a time-dependent analysis applied to a selection of flaring gamma-ray blazars observed by the FERMI/LAT experiment and by TeV Cherenkov telescopes using five years of ANTARES data taken from 2008 to 2012. The results are compatible with fluctuations of the background. Upper limits on the neutrino fluence have been produced and compared to the measured gamma-ray spectral energy distribution.
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Addazi, A., Valle, J. W. F., & Vaquera-Araujo, C. A. (2016). String completion of an SU(3)(c) x SU(3)(L) x U(1)(X) electroweak model. Phys. Lett. B, 759, 471–478.
Abstract: The extended electroweak SU(3)(c) circle times SU(3)(L) circle times U(1)(X) symmetry framework “explaining” the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (un)oriented open strings, on Calabi-Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron-antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.
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Real, D., Calvo, D., Zornoza, J. D., Manzaneda, M., Gozzini, R., Ricolfe-Viala, C., et al. (2024). Fast Coincidence Filter for Silicon Photomultiplier Dark Count Rate Rejection. Sensors, 24(7), 2084–12pp.
Abstract: Silicon Photomultipliers find applications across various fields. One potential Silicon Photomultiplier application domain is neutrino telescopes, where they may enhance the angular resolution. However, the elevated dark count rate associated with Silicon Photomultipliers represents a significant challenge to their widespread utilization. To address this issue, it is proposed to use Silicon Photomultipliers and Photomultiplier Tubes together. The Photomultiplier Tube signals serve as a trigger to mitigate the dark count rate, thereby preventing undue saturation of the available bandwidth. This paper presents an investigation into a fast and resource-efficient method for filtering the Silicon Photomultiplier dark count rate. A low-resource and fast coincident filter has been developed, which removes the Silicon Photomultiplier dark count rate by using as a trigger the Photomultiplier Tube input signals. The architecture of the coincidence filter, together with the first results obtained, which validate the effectiveness of this method, is presented.
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Abgrall, N. et al, Cervera-Villanueva, A., Escudero, L., Monfregola, L., & Stamoulis, P. (2011). Time projection chambers for the T2K near detectors. Nucl. Instrum. Methods Phys. Res. A, 637(1), 25–46.
Abstract: The T2K experiment is designed to study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large Super-Kamiokande detector located 295 km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to better understand neutrino interactions at the energy scale below a few GeV. A key element of the near detectors is the ND280 tracker, consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The data collected with the tracker are used to study charged current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. The tracker is surrounded by the former UA1/NOMAD dipole magnet and the TPCs measure the charges, momenta, and particle types of charged particles passing through them. Novel features of the TPC design include its rectangular box layout constructed from composite panels, the use of bulk micromegas detectors for gas amplification, electronics readout based on a new ASIC, and a photoelectron calibration system. This paper describes the design and construction of the TPCs, the micromegas modules, the readout electronics, the gas handling system, and shows the performance of the TPCs as deduced from measurements with particle beams, cosmic rays, and the calibration system.
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ANTARES Collaboration(Adrian-Martinez, S. et al), Barrios-Marti, J., Gomez-Gonzalez, J. P., Hernandez-Rey, J. J., Lambard, G., Mangano, S., et al. (2016). Time calibration with atmospheric muon tracks in the ANTARES neutrino telescope. Astropart Phys., 78, 43–51.
Abstract: The ANTARES experiment consists of an array of photomultipliers distributed along 12 lines and located deep underwater in the Mediterranean Sea. It searches for astrophysical neutrinos collecting the Cherenkov light induced by the charged particles, mainly muons, produced in neutrino interactions around the detector. Since at energies of similar to 10 TeV the muon and the incident neutrino are almost collinear, it is possible to use the ANTARES detector as a neutrino telescope and identify a source of neutrinos in the sky starting from a precise reconstruction of the muon trajectory. To get this result, the arrival times of the Cherenkov photons must be accurately measured. A to perform time calibrations with the precision required to have optimal performances of the instrument is described. The reconstructed tracks of the atmospheric muons in the ANTARES detector are used to determine the relative time offsets between photomultipliers. Currently, this method is used to obtain the time calibration constants for photomultipliers on different lines at a precision level of 0.5 ns. It has also been validated for calibrating photomultipliers on the same line, using a system of LEDs and laser light devices.
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ANTARES Collaboration(Aguilar, J. A. et al), Bigongiari, C., Dornic, D., Emanuele, U., Gomez-Gonzalez, J. P., Hernandez-Rey, J. J., et al. (2011). Time calibration of the ANTARES neutrino telescope. Astropart Phys., 34(7), 539–549.
Abstract: The ANTARES deep-sea neutrino telescope comprises a three-dimensional array of photomultipliers to detect the Cherenkov light induced by upgoing relativistic charged particles originating from neutrino interactions in the vicinity of the detector. The large scattering length of light in the deep sea facilitates an angular resolution of a few tenths of a degree for neutrino energies exceeding 10 TeV. In order to achieve this optimal performance, the time calibration procedures should ensure a relative time calibration between the photomultipliers at the level of similar to 1 ns. The methods developed to attain this level of precision are described.
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KM3NeT Collaboration(Aiello, S. et al), Alves Garre, S., Calvo, D., Carretero, V., Colomer, M., Gozzini, S. R., et al. (2022). Nanobeacon: A time calibration device for the KM3NeT neutrino telescope. Nucl. Instrum. Methods Phys. Res. A, 1040, 167132–13pp.
Abstract: The KM3NeT Collaboration is currently constructing a multi-site high-energy neutrino telescope in the Mediterranean Sea consisting of matrices of pressure-resistant glass spheres, each holding a set of 31 small-area photomultipliers. The main goals of the telescope are the observation of neutrino sources in the Universe and the measurement of the neutrino oscillation parameters with atmospheric neutrinos. A relative time synchronisation between photomultipliers of the nanosecond order needed to guarantee the required angular resolution of the detector. Due to the large detector volumes to be instrumented by KM3NeT, a cost reduction of the different systems is a priority. To this end, the inexpensive Nanobeacon has been designed and developed by the KM3NeT Collaboration to be used for detector time-calibration studies. At present, more than 600 & nbsp;Nanobeacons have been already produced. The characterisation of the optical pulse and the wavelength emission profile of the devices is critical for the time calibration. The optical pulse rise time has been quantified as less than 3 ns, while the Full Width Half Maximum is less than 6 ns. The wavelength drift, due to a variation of the supply voltage, has also been qualified as lower than 10 nm for the full range of the Nanobeacon. In this paper, more details about the main features of the Nanobeacon design, production and operation, together with the main properties of the light pulse generated are described.
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Abraham, R. M. et al, & Garcia Soto, A. (2022). Tau neutrinos in the next decade: from GeV to EeV. J. Phys. G, 49(11), 110501–148pp.
Abstract: Tau neutrinos are the least studied particle in the standard model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop.
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T2K Collaboration(Abe, K. et al), Antonova, M., Cervera-Villanueva, A., Fernandez, P., Izmaylov, A., & Novella, P. (2019). Search for neutral-current induced single photon production at the ND280 near detector in T2K. J. Phys. G, 46(8), 08LT01–16pp.
Abstract: Neutrino neutral-current (NC) induced single photon production is a sub-leading order process for accelerator-based neutrino beam experiments including T2K. It is, however, an important process to understand because it is a background for electron (anti)neutrino appearance oscillation experiments. Here, we performed the first search of this process below 1 GeV using the fine-grained detector at the T2K ND280 off-axis near detector. By reconstructing single photon kinematics from electron-positron pairs, we achieved 95% pure gamma ray sample from 5.738 x 10(20) protons-on-targets neutrino mode data. We do not find positive evidence of NC induced single photon production in this sample. We set the model-dependent upper limit on the cross-section for this process, at 0.114 x 10(-38) cm(2) (90% C.L.) per nucleon, using the J-PARC off-axis neutrino beam with an average energy of < E-v > similar to 0.6 GeV. This is the first limit on this process below 1 GeV which is important for current and future oscillation experiments looking for electron neutrino appearance oscillation signals.
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