192916821
The NEXT experiment for neutrinoless double beta decay searches
The goal of the NEXT experiment is the observation of the neutrinoless double beta decay in 136Xe using a gaseous xenon TPC with electroluminescent amplification and specialized photodetector arrays for calorimetry and tracking. After a prototyping period (2009-2014) where the technique was demonstrated, the Collaboration has completed the construction and started the operation of its first phase (NEXT-White or NEW) in the Laboratorio Subterraneo de Canfranc, in the Spanish Pyrenees, with the objectives of measuring in-situ the NEXT background model and the two-neutrino mode of the double beta decay under a radiopure regime. After running NEW, the Collaboration will operate a bigger detector, NEXT-100, which will look for the neutrinoless decay mode.
53333389
Radiopurity assessment of the tracking readout for the NEXT double beta decay experiment
The ``Neutrino Experiment with a Xenon Time-Projection Chamber'' (NEXT) is intended to investigate the neutrinoless double beta decay of 136Xe, which requires a severe suppression of potential backgrounds; therefore, an extensive screening and selection process is underway to control the radiopurity levels of the materials to be used in the experimental set-up of NEXT. The detector design combines the measurement of the topological signature of the event for background discrimination with the energy resolution optimization. Separate energy and tracking readout planes are based on different sensors: photomultiplier tubes for calorimetry and silicon multi-pixel photon counters for tracking. The design of a radiopure tracking plane, in direct contact with the gas detector medium, was specially challenging since the needed components like printed circuit boards, connectors, sensors or capacitors have typically, according to available information in databases and in the literature, activities too large for experiments requiring ultra-low background conditions. Here, the radiopurity assessment of tracking readout components based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterraaneo de Canfranc (Spain) is described. According to the obtained results, radiopure enough printed circuit boards made of kapton and copper, silicon photomultipliers and other required components, fulfilling the requirement of an overall background level in the region of interest of at most 8×10−4 counts keV−1 kg−1 y−1, have been identified.
122106372
Forward pi+/- production in p-O(2) and p-N(2) interactions at 12-GeV/c
Measurements of double-differential charged pion production cross-sections in interactions of 12 GeV/c protons on O2 and N2 thin targets are presented in the kinematic range 0.5 GeV/c ⩽pπ<8 GeV/c and 50 mrad ⩽θπ<250 mrad (in the laboratory frame) and are compared with p–C results. For p–N2 (p–O2) interactions the analysis is performed using 38576 (7522) reconstructed secondary pions. The analysis uses the beam instrumentation and the forward spectrometer of the HARP experiment at CERN PS. The measured cross-sections have a direct impact on the precise calculation of atmospheric neutrino fluxes and on the improved reliability of extensive air shower simulations by reducing the uncertainties of hadronic interaction models in the low energy range. In particular, the present results allow the common hypothesis that p–C data can be used to predict the p–N2 and p–O2 pion production cross-sections to be tested
119196633
Results of the material screening program of the NEXT experiment
The 'Neutrino Experiment with a Xenon TPC (NEXT)', intended to investigate neutrinoless double beta decay, requires extremely low background levels. An extensive material screening and selection process to assess the radioactivity of components is underway combining several techniques, including germanium gamma-ray spectrometry performed at the Canfranc Underground Laboratory; recent results of this material screening program are presented here.
122699398
Forward production of charged pions with incident pi(+/-) on nuclear targets measured at the CERN PS
Abstract Measurements of the double-differential π ± production cross-section in the range of momentum 0.5 GeV / c ⩽ p ⩽ 8.0 GeV / c and angle 0.025 rad ⩽ θ ⩽ 0.25 rad in interactions of charged pions on beryllium, carbon, aluminium, copper, tin, tantalum and lead are presented. These data represent the first experimental campaign to systematically measure forward pion hadroproduction. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. Incident particles, impinging on a 5% nuclear interaction length target, were identified by an elaborate system of beam detectors. The tracking and identification of the produced particles was performed using the forward spectrometer of the HARP detector. Results are obtained for the double-differential cross-sections d 2 σ / d p d Ω mainly at four incident pion beam momenta (3 GeV/ c , 5 GeV/ c , 8 GeV/ c and 12 GeV/ c ). The measurements are compared with the GEANT4 and MARS Monte Carlo simulation.
109935636
Comparison of large-angle production of charged pions with incident protons on cylindrical long and short targets
We gratefully acknowledge the help and support of the PS beam staff and of the numerous technical collaborators who contributed to the detector design, construction, commissioning and operation. In particular, we would like to thank G. Barichello, R. Brocard, K. Burin, V. Carassiti, F. Chignoli, D. Conventi, G. Decreuse, M. Delattre, C. Detraz, A. Domeniconi, M. Dwuznik, F. Evangelisti, B. Friend, A. Iaciofano, I. Krasin, D. Lacroix, J.-C. Legrand, M. Lobello, M. Lollo, J. Loquet, F. Marinilli, J. Mulon, L. Musa, R. Nicholson, A. Pepato, P. Petev, X. Pons, I. Rusinov, M. Scandurra, E. Usenko, and R. van der Vlugt, for their support in the construction of the detector. The collaboration acknowledges the major contributions and advice of M. Baldo-Ceolin, L. Linssen, M.T. Muciaccia and A. Pullia during the construction of the experiment. The collaboration is indebted to V. Ableev, P. Arce, F. Bergsma, P. Binko, E. Boter, C. Buttar, M. Calvi, M. Campanelli, C. Cavion, A. Chukanov, A. De Min, M. Doucet, D. Dullmann, R. Engel, V. Ermilova, W. Flegel, P. Gruber, Y. Hayato, P. Hodgson, A. Ichikawa, I. Kato, O. Klimov, T. Kobayashi, D. Kustov, M. Laveder, M. Mass, H. Meinhard, T. Nakaya, K. Nishikawa, M. Paganoni, F. Paleari, M. Pasquali, J. Pasternak, C. Pattison, M. Placentino, S. Robbins, G. Santin, V. Serdiouk, S. Simone, A. Tornero, S. Troquereau, S. Ueda, A. Valassi, F. Vannucci and K. Zuber for their contributions to the experiment and to P. Dini for help in MC production. 
We acknowledge the contributions of V. Ammosov, G. Chelkov, D. Dedovich, F. Dydak, M. Gostkin, A. Guskov, D. Khartchenko, V. Koreshev, Z. Kroumchtein, I. Nefedov, A. Semak, J. Wotschack, V. Zaets and A. Zhemchugov to the work described in this paper. 
The experiment was made possible by grants from the Institut Interuniversitaire des Sciences Nucleaires and the Interuniversitair Instituut voor Kernwetenschappen (Belgium), Ministerio de Educacion y Ciencia, Grant FPA2003-06921-c02-02 and Generalitat Valenciana, grant GV00-054-1, CERN (Geneva, Switzerland), the German Bundesministerium fur Bildung und Forschung (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), INR RAS (Moscow), the Russian Foundation for Basic Research (grant 08-02-00018) and the Particle Physics and Astronomy Research Council (UK). We gratefully acknowledge their support. This work was supported in part by the Swiss National Science Foundation and the Swiss Agency for Development and Cooperation in the framework of the programme SCOPES - Scientific co-operation between Eastern Europe and Switzerland.
14309262
A Fermi surface model for large supersymmetric AdS5 black holes
We identify a large family of 1/16 BPS operators in = 4 SYM that qualitatively reproduce the relations between charge, angular momentum and entropy in regular supersymmetric AdS5 black holes when the main contribution to their masses is given by their angular momentum.
55669946
Emergent IR dual 2d CFTs in charged AdS5 black holes
We study the possible dynamical emergence of IR conformal invariance describing the low energy excitations of near-extremal R-charged global AdS5 black holes. We find interesting behavior especially when we tune parameters in such a way that the relevant extremal black holes have classically vanishing horizon area, i.e. no classical ground-state entropy, and when we combine the low energy limit with a large N limit of the dual gauge theory. We consider both near-BPS and non-BPS regimes and their near horizon limits, emphasize the differences between the local AdS3 throats emerging in either case, and discuss potential dual IR 2d CFTs for each case. We compare our results with the predictions obtained from the Kerr/CFT correspondence, and obtain a natural quantization for the central charge of the near-BPS emergent IR CFT which we interpret in terms of the open strings stretched between giant gravitons.
15394078
Brane Effective Actions, Kappa-Symmetry and Applications
This is a review on brane effective actions, their symmetries and some of their applications. Its first part covers the Green-Schwarz formulation of single M- and D-brane effective actions focusing on kinematical aspects: the identification of their degrees of freedom, the importance of world volume diffeomorphisms and kappa symmetry to achieve manifest spacetime covariance and supersymmetry, and the explicit construction of such actions in arbitrary on-shell supergravity backgrounds.Its second part deals with applications. First, the use of kappa symmetry to determine supersymmetric world volume solitons. This includes their explicit construction in flat and curved backgrounds, their interpretation as Bogomol’nyi-Prasad-Sommerfield (BPS) states carrying (topological) charges in the supersymmetry algebra and the connection between supersymmetry and Hamiltonian BPS bounds. When available, I emphasise the use of these solitons as constituents in microscopic models of black holes. Second, the use of probe approximations to infer about the non-trivial dynamics of strongly-coupled gauge theories using the anti de Sitter/conformal field theory (AdS/CFT) correspondence. This includes expectation values of Wilson loop operators, spectrum information and the general use of D-brane probes to approximate the dynamics of systems with small number of degrees of freedom interacting with larger systems allowing a dual gravitational description.Its final part briefly discusses effective actions for N D-branes and M2-branes. This includes both Super-Yang-Mills theories, their higher-order corrections and partial results in covariantising these couplings to curved backgrounds, and the more recent supersymmetric Chern-Simons matter theories describing M2-branes using field theory, brane constructions and 3-algebra considerations.
121596909
RESTRICTIONS FROM GEOMETRY ON QUANTIZATION IN CURVED SPACE--TIME.
119108532
Helical Luttinger Liquids and three dimensional black holes
We use the AdS/CFT correspondence to discuss an equivalence between a helical, strongly coupled Luttinger liquid and a fermion propagating in the background of a topologically charged black hole in three dimensions. The Fermi level is set by the topological charges, thus surmounting difficulties in low dimensions of the standard approach using Coulomb charged black holes. The construction is fully embeddable in string theory, and the microscopic Lagrangian is explicitly known. The retarded Green function at low temperature and energy arises from the geometry very near the black hole horizon, a structure that is universal for all cold, charged liquids with a dual $\mathbb{R}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}^{s}$ invariant description in gravity. This explains a subtle relationship between Luttinger physics and the infrared behavior of higher dimensional non-Fermi liquids in the AdS/CFT correspondence.