First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment

• DOI: 10.1007/jhep01(2016)104
• Publication Date: 2016-01-21T03:42:54Z
• Authors: P. Ferrario; A. Laing; N. López-March; J. J. Gómez-Cadenas; V. Álvarez; C. D. R. Azevedo; F. I. G. Borges; S. Cárcel; S. Cebrián; A. Cervera; C. A. N. Conde; T. Dafni; J. Díaz; M. Diesburg; R. Esteve; L. M. P. Fernandes; A. L. Ferreira; E. D. C. Freitas; V. M. Gehman; A. Goldschmidt; D. González-Díaz; R. M. Gutiérrez; J. Hauptman; C. A. O. Henriques; J. A. Hernando Mo...; I. G. Irastorza; L. Labarga; P. Lebrun; I. Liubarsky; D. Lorca; M. Losada; G. Luzón; A. Marí; J. Martín-Albo; G. Martínez-Lema; A. Martínez; T. Miller; F. Monrabal; M. Monserrate; C. M. B. Monteiro; F. J. Mora; L. M. Moutinho; J. Muñoz Vidal; M. Nebot-Guinot; P. Novella; D. Nygren; A. Para; J. Pérez; J. L. Pérez Aparicio; M. Querol; J. Renner; L. Ripoll; J. Rodríguez; F. P. Santos; J. M. F. dos Santos; L. Serra; D. Shuman; A. Simón; C. Sofka; M. Sorel; J. F. Toledo; J. Torrent; Z. Tsamalaidze; J. F. C. A. Veloso; J. A. Villar; R. Webb; J. T. White; N. Yahlali; H. Yepes-Ramírez
• Keywords: Ionization; Physics - Instrumentation and Detectors; Xenon; Nuclear physics; Atomic; 01 natural sciences; 7. Clean energy; High Energy Physics - Experiment; High Energy Physics - Experiment (hep-ex); Particle and Plasma Physics; Engineering; Dark Matter; Nanotechnology; High-Energy Collider; Double Beta Decay; Mathematical Physics; Quantum Physics; Physics; Particle physics; Particle and High Energy Physics; Instrumentation and Detectors (physics.ins-det); Nuclear and Plasma Physics; Neutrino Detection; Nuclear & Particles Physics; Nuclear and plasma physics; Programming language; Desintegració beta; Time projection chamber; Particle and high energy physics; Dark matter (Astronomy); Mathematical physics; SIGNAL (programming language); Physical Sciences; Matèria fosca (Astronomia); MECANICA DE LOS MEDIOS CONTINUOS Y TEORIA DE ESTRUCTURAS; Nuclear and High Energy Physics; Geometry; FOS: Physical sciences; 530; Electron; Quantum mechanics; Particle Dark Matter and Detection Methods; TECNOLOGIA ELECTRONICA; Layer (electronics); Neutrino; 0103 physical sciences; FOS: Mathematics; Nuclear; Particle Physics and High-Energy Collider Experiments; Ion; Topology (electrical circuits); Signature (topology); FOS: Nanotechnology; Molecular; Beta Decay; Double beta decay; Computer science; Materials science; Physics and Astronomy; Electroluminescence; Double-Beta Decay; Electrical engineering; Neutrino Flavor Transformation and Detection; Energy (signal processing); Mathematics

The NEXT experiment aims to observe the neutrinoless double beta decay of xenon in a high-pressure Xe136 gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qbb. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype. Single electrons resulting from the interactions of Na22 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the Th228 decay chain were used to represent the background and the signal in a double beta decay. These data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 +- 1.4 (stat.)%, while maintaining an efficiency of 66.7 +- 1% for signal events.