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Author BABAR Collaboration (del Amo Sanchez, P. et al); Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A.
Title Test of Lepton Universality in Y(1S) Decays at BABAR Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 104 Issue 19 Pages 191801 - 7pp
Keywords
Abstract (down) The ratio R-tau mu(Y(1S)) = Gamma Y(1S)->tau(+)tau(-)/Gamma(+)(-)(Y(1S)->mu)(mu) is measured using a sample of (121.8 +/- 1.2) x 10(6)Y(3S) events recorded by the BABAR detector. This measurement is intended as a test of lepton universality and as a search for a possible light pseudoscalar Higgs boson. In the standard model (SM) this ratio is expected to be close to 1. Any significant deviations would violate lepton universality and could be introduced by the coupling to a light pseudoscalar Higgs boson. The analysis studies the decays Y(3S) -> Y(1S)pi(+)pi(-), Y(1S) -> l(+)l(-), where l = mu, tau. The result, R-tau μ(Y(1S)) = 1.005 +/- 0.013(stat) +/- 0.022(syst), shows no deviation from the expected SM value, while improving the precision with respect to previous measurements.
Address [Sanchez, P. del Amo; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.] Univ Savoie, Lab Annecy Le Vieux Phys Particules, CNRS, IN2P3, F-74941 Annecy Le Vieux, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000277699600013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 451
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Author NEXT Collaboration (Martinez-Lema, G. et al); Palmeiro, B.; Botas, A.; Laing, A.; Renner, J.; Simon, A.; Alvarez, V.; Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Kekic, M.; Lopez-March, N.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Perez, J.; Querol, M.; Rodriguez, J.; Romo-Lugue, C.; Sorel, M.; Torrent, J.; Yahlali, N.
Title Calibration of the NEXT-White detector using Kr-83m decays Type Journal Article
Year 2018 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 13 Issue Pages P10014 - 21pp
Keywords Charge transport; multiplication and electroluminescence in rare gases and liquids; Gaseous imaging and tracking detectors; Time projection Chambers (TPC); Double-beta decay detectors
Abstract (down) The NEXT-White (NEW) detector is currently the largest radio-pure high-pressure xenon gas time projection chamber with electroluminescent readout in the world. It has been operating at Laboratorio Subterraneo de Canfranc (LSC) since October 2016. This paper describes the calibrations performed using Kr-83m decays during a long run taken from March to November 2017 (Run II). Krypton calibrations are used to correct for the finite drift-electron lifetime as well as for the dependence of the measured energy on the event transverse position which is caused by variations in solid angle coverage both for direct and reflected light and edge effects. After producing calibration maps to correct for both effects we measure an excellent energy resolution for 41.5 keV point-like deposits of (4.553 +/- 0.010 (stat.) +/- 0.324 (sys.)) % FWHM in the full chamber and (3.804 +/- 0.013 (stat.) +/- 0.112 (sys.)) % FWHM in a restricted fiducial volume. Using naive 1/root E scaling, these values translate into resolutions of (0.5916 +/- 0.0014 (stat.) +/- 0.0421 (sys.)) % FWHM and (0.4943 +/- 0.0017 (stat.) +/- 0.0146 (sys.)) % FWHM at the Q(beta beta) energy of xenon double beta decay (2458 keV), well within range of our target value of 1%.
Address [Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: gonzalo.martinez.lema@usc.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000447061800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3754
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Author NEXT Collaboration (Ferrario, P. et al); Laing, A.; Lopez-March, N.; Gomez-Cadenas, J.J.; Alvarez, V.; Carcel, S.; Cervera-Villanueva, A.; Diaz, J.; Liubarsky, I.; Lorca, D.; Martin-Albo, J.; Martinez, A.; Monrabal, F.; Monserrate, M.; Muñoz Vidal, J.; Nebot-Guinot, M.; Novella, P.; Querol, M.; Renner, J.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Yahlali, N.
Title First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment Type Journal Article
Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 104 - 18pp
Keywords Dark Matter; Double Beta Decay
Abstract (down) The NEXT experiment aims to observe the neutrinoless double beta decay of Xe-136 in a high-pressure xenon 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 Q(beta beta). 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 Na-22 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the Th-228 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.
Address [Ferrario, P.; Laing, A.; Lopez-March, N.; Gomez-Cadenas, J. J.; Alvarez, V.; Carcel, S.; Cervera, A.; Diaz, J.; Liubarsky, I.; Lorca, D.; Martin-Albo, J.; Martinez, A.; Monrabal, F.; Monserrate, M.; Munoz Vidal, J.; Nebot-Guinot, M.; Novella, P.; Querol, M.; Renner, J.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Yahlali, N.] CSIC, Inst Fis Corpuscular IFIC, Jose Beltran 2, Valencia 46980, Spain, Email: paola.ferrario@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000370438900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2560
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Author NEXT Collaboration (Novella, P. et al); Carcel, S.; Carrion, J.V.; Lopez, F.; Lopez-March, N.; Martin-Albo, J.; Muñoz Vidal, J.; Querol, M.; Romo-Luque, C.; Sorel, M.; Uson, A.
Title Demonstration of neutrinoless double beta decay searches in gaseous xenon with NEXT Type Journal Article
Year 2023 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 190 - 35pp
Keywords Dark Matter and Double Beta Decay (experiments); Rare Decay
Abstract (down) The NEXT experiment aims at the sensitive search of the neutrinoless double beta decay in Xe-136, using high-pressure gas electroluminescent time projection chambers. The NEXT-White detector is the first radiopure demonstrator of this technology, operated in the Laboratorio Subterr & aacute;neo de Canfranc. Achieving an energy resolution of 1% FWHM at 2.6 MeV and further background rejection by means of the topology of the reconstructed tracks, NEXT-White has been exploited beyond its original goals in order to perform a neu-trinoless double beta decay search. The analysis considers the combination of 271.6 days of Xe-136-enriched data and 208.9 days of 136Xe-depleted data. A detailed background mod-eling and measurement has been developed, ensuring the time stability of the radiogenic and cosmogenic contributions across both data samples. Limits to the neutrinoless mode are obtained in two alternative analyses: a background-model-dependent approach and a novel direct background-subtraction technique, offering results with small dependence on the background model assumptions. With a fiducial mass of only 3.50 +/- 0.01 kg of Xe-136-enriched xenon, 90% C.L. lower limits to the neutrinoless double beta decay are found in the T-1/2(0 nu) > 5.5x10(23) -1.3x10(24) yr range, depending on the method. The presented techniques stand as a pro of-of-concept for the searches to be implemented with larger NEXT detectors.
Address [Hauptman, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: pau.novella@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:001085073500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5798
Permanent link to this record
 

 
Author NEXT Collaboration (Henriques, C.A.O. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Kekic, M.; Laing, A.; Lopez-March, N.; Martinez, A.; Martinez-Lema, G.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Romo-Luque, C.; Simon, A.; Sorel, M.; Yahlali, N.
Title Electroluminescence TPCs at the thermal diffusion limit Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 027 - 23pp
Keywords Dark Matter and Double Beta Decay (experiments); Photon production; Particle correlations and fluctuations; Rare decay
Abstract (down) The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the Xe-136 isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO2, CH4 and CF4) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 for pure xenon down to 2.5 using additive concentrations of about 0.05%, 0.2% and 0.02% for CO2, CH4 and CF4, respectively. Our results show that CF4 admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH4 presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO2 and CH4 show potential as molecular additives in a large xenon TPC. While CO2 has some operational constraints, making it difficult to be used in a large TPC, CH4 shows the best performance and stability as molecular additive to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%, which is only slightly worse than the one obtained for pure xenon. We demonstrate the possibility to have an electroluminescence TPC operating very close to the thermal diffusion limit without jeopardizing the TPC performance, if CO2 or CH4 are chosen as additives.
Address [Henriques, C. A. O.; Monteiro, C. M. B.; Freitas, E. D. C.; Mano, R. D. P.; Jorge, M. R.; Fernandes, A. F. M.; Fernandes, L. M. P.; dos Santos, J. M. F.] Univ Coimbra, Phys Dept, LIBPhys, Rua Larga, P-3004516 Coimbra, Portugal, Email: pancho@gian.fis.uc.pt
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000455157300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3873
Permanent link to this record