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1. Sensitivity of a tonne-scale NEXT detector for neutrinoless double-beta decay searches

Author: The NEXT collaboration, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrián, E. Church, C. A. N. Conde, T. Contreras, A. A. Denisenko, G. Díaz, J. Díaz, J. Escada, R. Esteve, R. Felkai, L. M. P. Fernandes, P. Ferrario, A. L. Ferreira, F. Foss, E. D. C. Freitas, Z. Freixa, J. Generowicz, A. Goldschmidt, J. J. Gómez-Cadenas, R. González, D. González-Díaz, S. Gosh, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, J. A. Hernando Morata, P. Herrero, V. Herrero, J. Ho, Y. Ifergan, B. J. P. Jones, M. Kekic, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, M. Martínez-Vara, G. Martínez-Lema, A. D. McDonald, Z. E. Meziani, F. Monrabal, C. M. B. Monteiro, F. J. Mora, J. Muñoz Vidal, C. Newhouse, P. Novella, D. R. Nygren, E. Oblak, B. Palmeiro, A. Para, J. Pérez, M. Querol, A. Redwine, J. Renner, L. Ripoll, I. Rivilla, Y. Rodríguez García, J. Rodríguez, C. Rogero, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, M. Sorel, C. Stanford, J. M. R. Teixeira, P. Thapa, J. F. Toledo, J. Torrent, A. Usón, J. F. C. A. Veloso, T. T. Vuong, R. Webb, R. Weiss-Babai, J. T. White, K. Woodruff, and N. Yahlali
Subjects: Dark Matter and Double Beta Decay (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0νββ) decay of 136Xe using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0νββ decay better than 1027 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.
Published: 2021
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2. Boosting background suppression in the NEXT experiment through Richardson-Lucy deconvolution

Author: The NEXT collaboration, A. Simón, Y. Ifergan, A. B. Redwine, R. Weiss-Babai, L. Arazi, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A. I. Aranburu, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrián, E. Church, C. A. N. Conde, T. Contreras, F. P. Cossío, A. A. Denisenko, G. Díaz, J. Díaz, J. Escada, R. Esteve, R. Felkai, L. M. P. Fernandes, P. Ferrario, A. L. Ferreira, F. Foss, E. D. C. Freitas, Z. Freixa, J. Generowicz, A. Goldschmidt, J. J. Gómez-Cadenas, R. González, D. González-Díaz, S. Gosh, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, J. A. Hernando Morata, P. Herrero, V. Herrero, J. Ho, B. J. P. Jones, M. Kekic, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, M. Martínez-Vara, G. Martínez-Lema, A. D. McDonald, Z.-E. Meziani, F. Monrabal, C. M. B. Monteiro, F. J. Mora, J. Muñoz Vidal, C. Newhouse, P. Novella, D. R. Nygren, E. Oblak, M. Odriozola-Gimeno, B. Palmeiro, A. Para, J. Pérez, M. Querol, J. Renner, L. Ripoll, I. Rivilla, Y. Rodríguez García, J. Rodríguez, C. Rogero, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, M. Sorel, C. Stanford, J. M. R. Teixeira, P. Thapa, J. F. Toledo, J. Torrent, A. Usón, J. F. C. A. Veloso, T. T. Vuong, R. Webb, J. T. White, K. Woodruff, and N. Yahlali
Subjects: Dark Matter and Double Beta Decay (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract Next-generation neutrinoless double beta decay experiments aim for half-life sensitivities of ∼ 1027 yr, requiring suppressing backgrounds to < 1 count/tonne/yr. For this, any extra background rejection handle, beyond excellent energy resolution and the use of extremely radiopure materials, is of utmost importance. The NEXT experiment exploits differences in the spatial ionization patterns of double beta decay and single-electron events to discriminate signal from background. While the former display two Bragg peak dense ionization regions at the opposite ends of the track, the latter typically have only one such feature. Thus, comparing the energies at the track extremes provides an additional rejection tool. The unique combination of the topology-based background discrimination and excellent energy resolution (1% FWHM at the Q-value of the decay) is the distinguishing feature of NEXT. Previous studies demonstrated a topological background rejection factor of ∼ 5 when reconstructing electron-positron pairs in the 208Tl 1.6 MeV double escape peak (with Compton events as background), recorded in the NEXT-White demonstrator at the Laboratorio Subterráneo de Canfranc, with 72% signal efficiency. This was recently improved through the use of a deep convolutional neural network to yield a background rejection factor of ∼ 10 with 65% signal efficiency. Here, we present a new reconstruction method, based on the Richardson-Lucy deconvolution algorithm, which allows reversing the blurring induced by electron diffusion and electroluminescence light production in the NEXT TPC. The new method yields highly refined 3D images of reconstructed events, and, as a result, significantly improves the topological background discrimination. When applied to real-data 1.6 MeV e − e + pairs, it leads to a background rejection factor of 27 at 57% signal efficiency.
Published: 2021
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3. Demonstration of background rejection using deep convolutional neural networks in the NEXT experiment

Author: The NEXT collaboration, M. Kekic, C. Adams, K. Woodruff, J. Renner, E. Church, M. Del Tutto, J. A. Hernando Morata, J. J. Gómez-Cadenas, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R. Azevedo, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrián, C. A. N. Conde, T. Contreras, G. Díaz, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, A. F. M. Fernandes, L. M. P. Fernandes, P. Ferrario, A. L. Ferreira, E. D. C. Freitas, J. Generowicz, S. Ghosh, A. Goldschmidt, D. González-Díaz, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, P. Herrero, V. Herrero, Y. Ifergan, B. J. P. Jones, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, G. Martínez-Lema, M. Martínez-Vara, A. D. McDonald, Z.-E. Meziani, F. Monrabal, C. M. B. Monteiro, F. J. Mora, J. Muñoz Vidal, P. Novella, D. R. Nygren, B. Palmeiro, A. Para, J. Pérez, M. Querol, A. B. Redwine, L. Ripoll, Y. Rodríguez García, J. Rodríguez, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, C. Sofka, M. Sorel, T. Stiegler, J. F. Toledo, J. Torrent, A. Usón, J. F. C. A. Veloso, R. Webb, R. Weiss-Babai, J. T. White, and N. Yahlali
Subjects: Dark Matter and Double Beta Decay (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in 136Xe. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a 228Th calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses.
Published: 2021
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4. Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield

Author: The NEXT collaboration, A. F. M. Fernandes, C. A. O. Henriques, R. D. P. Mano, D. González-Díaz, C. D. R Azevedo, P. A. O. C. Silva, J. J. Gómez-Cadenas, E. D. C. Freitas, L. M. P. Fernandes, C. M. B. Monteiro, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrián, E. Church, C. A. N. Conde, T. Contreras, G. Díaz, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, P. Ferrario, A. L. Ferreira, J. Generowicz, S. Ghosh, A. Goldschmidt, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, J. A. Hernando Morata, P. Herrero, V. Herrero, Y. Ifergan, S. Johnston, B. J. P. Jones, M. Kekic, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, J. Martín-Albo, A. Martínez, G. Martínez-Lema, A. D. McDonald, F. Monrabal, F. J. Mora, J. Muñoz Vidal, P. Novella, D. R. Nygren, B. Palmeiro, A. Para, J. Pérez, F. Psihas, M. Querol, J. Renner, J. Repond, S. Riordan, L. Ripoll, Y. Rodríguez García, J. Rodríguez, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, C. Sofka, M. Sorel, T. Stiegler, J. F. Toledo, J. Torrent, A. Usón, J. F. C. A. Veloso, R. Webb, R. Weiss-Babai, J. T. White, K. Woodruff, and N. Yahlali
Subjects: Particle correlations and fluctuations, Photon production, Dark Matter and Double Beta Decay (experiments), Rare decay, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe–He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by ∼ 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures.
Published: 2020
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5. Radiogenic backgrounds in the NEXT double beta decay experiment

Author: The NEXT collaboration, P. Novella, B. Palmeiro, M. Sorel, A. Usón, P. Ferrario, J. J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrían, E. Church, C. A. N. Conde, T. Contreras, G. Díaz, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, A. F. M. Fernandes, L. M. P. Fernandes, A. L. Ferreira, E. D. C. Freitas, J. Generowicz, S. Ghosh, A. Goldschmidt, D. Gonźalez-Díaz, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, J. A. Hernando Morata, P. Herrero, V. Herrero, Y. Ifergan, S. Johnston, B. J. P. Jones, M. Kekic, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, G. Martínez-Lema, A. D. McDonald, F. Monrabal, C. M. B. Monteiro, F. J. Mora, J. Muñoz Vidal, D. R. Nygren, A. Para, J. Pérez, F. Psihas, M. Querol, J. Renner, J. Repond, S. Riordan, L. Ripoll, Y. Rodríguez García, J. Rodríguez, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, C. Sofka, T. Stiegler, J. F. Toledo, J. Torrent, J. F. C. A. Veloso, R. Webb, R. Weiss-Babai, J. T. White, K. Woodruff, and N. Yahlali
Subjects: Dark Matter and Double Beta Decay (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Q ββ ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events.
Published: 2019
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6. Demonstration of the event identification capabilities of the NEXT-White detector

Author: The NEXT collaboration, P. Ferrario, J. M. Benlloch-Rodríguez, G. Díaz López, J. A. Hernando Morata, M. Kekic, J. Renner, A. Usón, J. J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrían, E. Church, C. A. N. Conde, T. Contreras, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, A. F. M. Fernandes, L. M. P. Fernandes, A. L. Ferreira, E. D. C. Freitas, J. Generowicz, S. Ghosh, A. Goldschmidt, D. González-Díaz, R. Guenette, R. M. Gutíerrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, P. Herrero, V. Herrero, Y. Ifergan, S. Johnston, B. J. P. Jones, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, G. Martínez-Lema, A. D. McDonald, F. Monrabal, C. M. B. Monteiro, F. J. Mora, J. Muñoz Vidal, P. Novella, D. R. Nygren, B. Palmeiro, A. Para, J. Pérez, F. Psihas, M. Querol, J. Repond, S. Riordan, L. Ripoll, Y. Rodríguez García, J. Rodríguez, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, C. Sofka, M. Sorel, T. Stiegler, J. F. Toledo, J. Torrent, J. F. C. A. Veloso, R. Webb, R. Weiss-Babai, J. T. White, K. Woodruff, and N. Yahlali
Subjects: Dark Matter and Double Beta Decay (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat ± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat ± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies.
Published: 2019
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7. Energy calibration of the NEXT-White detector with 1% resolution near Q ββ of 136Xe

Author: The NEXT collaboration, J. Renner, G. Díaz López, P. Ferrario, J. A. Hernando Morata, M. Kekic, G. Martínez-Lema, F. Monrabal, J. J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrián, E. Church, C. A. N. Conde, T. Contreras, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, A. F. M. Fernandes, L. M. P. Fernandes, A. L. Ferreira, E. D. C. Freitas, J. Generowicz, S. Ghosh, A. Goldschmidt, D. González-Díaz, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, P. Herrero, V. Herrero, Y. Ifergan, S. Johnston, B. J. P. Jones, L. Labarga, A. Laing, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, A. D. McDonald, C. M. B. Monteiro, F.J. Mora, J. Muñoz Vidal, P. Novella, D. R. Nygren, B. Palmeiro, A. Para, J. Pérez, F. Psihas, M. Querol, J. Repond, S. Riordan, L. Ripoll, Y. Rodríguez García, J. Rodríguez, L. Rogers, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, C. Sofka, M. Sorel, T. Stiegler, J. F. Toledo, J. Torrent, A. Usón, J. F. C. A. Veloso, R. Webb, R. Weiss-Babai, J. T. White, K. Woodruff, and N. Yahlali
Subjects: Dark Matter and Double Beta Decay (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract Excellent energy resolution is one of the primary advantages of electroluminescent high-pressure xenon TPCs. These detectors are promising tools in searching for rare physics events, such as neutrinoless double-beta decay (ββ0ν), which require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for ββ0ν searches.
Published: 2019
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8. Sensitivity of a tonne-scale NEXT detector for neutrinoless double-beta decay searches

Author: R. Guenette, L. Ripoll, J.F. Toledo, S. Cárcel, B. J. P. Jones, P. Lebrun, A. Laing, C. Adams, N. Byrnes, A. Martínez, L.M.P. Fernandes, Javier Pérez, Iván Rivilla, F. Monrabal, I. J. Arnquist, N. López-March, J.M.R. Teixeira, Javier Rodríguez, F.I.G.M. Borges, M. Kekic, T. Contreras, A.D. McDonald, Celia Rogero, M. Losada, S. Cebrián, C. Newhouse, A.A. Denisenko, C.A.N. Conde, R.D.P. Mano, B. Palmeiro, J.A. Hernando Morata, L. Rogers, C. Romo-Luque, G. Díaz, A. Simón, Z. E. Meziani, R. Felkai, Zoraida Freixa, A. Goldschmidt, A. Usón, L. Labarga, E. Church, J. Hauptman, J.M.F. dos Santos, Kevin Bailey, C.M.B. Monteiro, J. Torrent, F.P. Santos, J.F.C.A. Veloso, E.D.C. Freitas, P. Herrero, R. Weiss-Babai, Diego González-Díaz, Y. Rodriguez Garcia, D.R. Nygren, Paola Ferrario, J. Ho, J. Renner, T.T. Vuong, Víctor H. Alvarez, J.T. White, A. Redwine, F.J. Mora, Y. Ifergan, Lior Arazi, V. Herrero, C.A.O. Henriques, E. Oblak, N. Yahlali, G. Martínez-Lema, K. Hafidi, M. Querol, A. Para, R. González, Romain Esteve, Roberto Gutiérrez, M. Sorel, C. Stanford, J. Escada, J. Haefner, A.L. Ferreira, J.V. Carrión, B. Romeo, F. Ballester, Frank W. Foss, C.D.R. Azevedo, S. Gosh, P. Thapa, R. C. Webb, J. M. Benlloch-Rodríguez, J. Muñoz Vidal, J. S. Díaz, M. Martínez-Vara, K. Woodruff, P. Novella, J. Martín-Albo, J.J. Gómez-Cadenas, J. Generowicz, European Commission, European Research Council, Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat Valenciana, Fundação para a Ciência e a Tecnologia (Portugal), Fundación 'la Caixa', and Department of Energy (US)
Subjects: Nuclear and High Energy Physics, chemistry.chemical_element, QC770-798, Parameter space, 01 natural sciences, 7. Clean energy, Atomic, Nuclear physics, Xenon, Particle and Plasma Physics, Double beta decay, Nuclear and particle physics. Atomic energy. Radioactivity, 0103 physical sciences, Dark Matter and Double Beta Decay (experiments), Nuclear, Sensitivity (control systems), 010306 general physics, Mathematical Physics, Physics, Quantum Physics, 010308 nuclear & particles physics, Raigs beta -- Desintegració, Detector, Molecular, Detectors, Nuclear & Particles Physics, chemistry, Beta rays -- Decay, Neutrino, Tonne, Order of magnitude
Abstract: The NEXT collaboration: et al., The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0νββ) decay of 136Xe using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0νββ decay better than 1027 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond., The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union’s Framework Programme for Research and Innovation Horizon 2020 (2014–2020) under the Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economía y Competitividad and the Ministerio de Ciencia, Innovación y Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program grants SEV-2014-0398 and CEX2018-000867-S, and the María de Maeztu Program MDM2016-0692; the Generalitat Valenciana of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014 and under projects UID/FIS/04559/2020 to fund the activities of LIBPhys-UC; the Pazy Foundation (Israel) under grants 877040 and 877041; the US Department of Energy under contracts number DE-AC02-06CH11357 (Argonne National Laboratory), DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0019223 / DE-SC0019054 (University of Texas at Arlington); and the University of Texas at Arlington. DGD acknowledges support from the Ramón y Cajal program (Spain) under contract number RYC-2015-18820. JM-A acknowledges support from Fundación Bancaria la Caixa (ID 100010434), grant code LCF/BQ/PI19/11690012, and from the Plan GenT program of the Generalitat Valenciana, grant code CIDEGENT/2019/049.
Published: 2021

9. Demonstration of background rejection using deep convolutional neural networks in the NEXT experiment

Author: T. Contreras, Z. E. Meziani, R. Weiss-Babai, I. J. Arnquist, J.V. Carrión, J. Renner, N. López-March, L. Rogers, F.J. Mora, J. Generowicz, T.M. Stiegler, Vicente Herrero, F.P. Santos, G. Martínez-Lema, C.M.B. Monteiro, R.D.P. Mano, L.M.P. Fernandes, J.M. Benlloch-Rodríguez, P. Herrero, C. Adams, N. Byrnes, B. Palmeiro, J.A. Hernando Morata, N. Yahlali, D. González-Díaz, Y. Rodriguez Garcia, J. S. Díaz, M. Martínez-Vara, P. Novella, F.I.G.M. Borges, Romain Esteve, J.F.C.A. Veloso, E.D.C. Freitas, J. Martin-Albo, M. Del Tutto, A. Usón, R. Guenette, F. Monrabal, Roberto Gutiérrez, A.D. McDonald, C.D.R. Azevedo, J.T. White, J.F. Toledo, S. Cárcel, P. Lebrun, A. Martínez, M. Diesburg, E. Church, A. Laing, Kevin Bailey, J. Rodríguez, M. Kekic, A.B. Redwine, C.A.O. Henriques, J. Escada, L. Ripoll, J. Torrent, Lior Arazi, B. J. P. Jones, Víctor H. Alvarez, J. Haefner, B. Romeo, R. Felkai, M. Losada, A. Goldschmidt, J. Hauptman, K. Woodruff, L. Labarga, Y. Ifergan, J.M.F. dos Santos, C. Romo-Luque, Javier Pérez, S. Cebrián, Sudip Ghosh, R. C. Webb, G. Díaz, F. Ballester, Paola Ferrario, D.R. Nygren, A.F.M. Fernandes, M. Querol, C. Sofka, A. Para, M. Sorel, A.L. Ferreira, K. Hafidi, C.A.N. Conde, A. Simón, J.J. Gómez-Cadenas, J. Muñoz Vidal, and UAM. Departamento de Física Teórica
Subjects: Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Calibration (statistics), Computer Science::Neural and Evolutionary Computation, Nuclear physics, FOS: Physical sciences, Topology (electrical circuits), 01 natural sciences, Convolutional neural network, Atomic, Partícules (Física nuclear), High Energy Physics - Experiment, Interaccions electró-positró, TECNOLOGIA ELECTRONICA, High Energy Physics - Experiment (hep-ex), Particle and Plasma Physics, Double beta decay, 0103 physical sciences, Dark Matter and Double Beta Decay (experiments), Nuclear, Nuclear Matrix, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, 010306 general physics, Electron-positron interactions, Mathematical Physics, Particles (Nuclear physics), Physics, Quantum Physics, 010308 nuclear & particles physics, business.industry, Event (computing), Network on, SIGNAL (programming language), Molecular, Física, Pattern recognition, Detector, Instrumentation and Detectors (physics.ins-det), Beta Decay, Nuclear & Particles Physics, Doble desintegració beta, Identification (information), lcsh:QC770-798, Física nuclear, Artificial intelligence, business
Abstract: [EN] Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in Xe-136. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a Th-228 calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses, This study used computing resources from Artemisa, co-funded by the European Union through the 2014-2020 FEDER Operative Programme of the Comunitat Valenciana, project DIFEDER/2018/048. This research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357. The NEXT collaboration acknowledges support from the following agencies and institutions: Xunta de Galicia (Centro singularde investigacion de Galicia accreditation 2019-2022), by European Union ERDF, and by the "Maria de Maeztu" Units of Excellence program MDM-2016-0692 and the Spanish Research State Agency"; the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad and the Ministerio de Ciencia, Innovacion y Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program grants SEV-20140398 and CEX2018-000867-S; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014 and under projects UID/FIS/04559/2020 to fund the activities of LIBPhys-UC; the U.S. Department of Energy under contracts number DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0019223/DE SC0019054 (University of Texas at Arlington); and the University of Texas at Arlington. DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC-2015 18820. JMA acknowledges support from Fundacion Bancaria "la Caixa" (ID 100010434), grant code LCF/BQ/PI19/11690012. We also warmly acknowledge the Laboratori Nazionali del Gran Sasso (LNGS) and the Dark Side collaboration for their help with TPB coating of various parts of the NEXT-White TPC. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment.
Published: 2021

10. The dynamics of ions on phased radio-frequency carpets in high pressure gases and application for barium tagging in xenon gas time projection chambers

Author: B.J.P. Jones, A. Raymond, K. Woodruff, N. Byrnes, A.A. Denisenko, F.W. Foss, K. Navarro, D.R. Nygren, T.T. Vuong, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, S. Ayet, C.D.R. Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, S. Bounasser, S. Cárcel, J.V. Carrión, S. Cebrián, E. Church, C.A.N. Conde, T. Contreras, F.P. Cossío, G. Díaz, J. Díaz, T. Dickel, J. Escada, R. Esteve, A. Fahs, R. Felkai, L.M.P. Fernandes, P. Ferrario, A.L. Ferreira, E.D.C. Freitas, Z. Freixa, J. Generowicz, A. Goldschmidt, J.J. Gómez-Cadenas, R. González, D. González-Díaz, R. Guenette, R.M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C.A.O. Henriques, J.A. Hernando Morata, P. Herrero-Gómez, V. Herrero, J. Ho, Y. Ifergan, M. Kekic, L. Labarga, A. Laing, P. Lebrun, D. Lopez Gutierrez, N. López-March, M. Losada, R.D.P. Mano, J. Martín-Albo, A. Martínez, G. Martínez-Lema, M. Martínez-Vara, A.D. McDonald, Z.E. Meziani, K. Mistry, F. Monrabal, C.M.B. Monteiro, F.J. Mora, J. Muñoz Vidal, P. Novella, E. Oblak, M. Odriozola-Gimeno, B. Palmeiro, A. Para, J. Pérez, M. Querol, A.B. Redwine, J. Renner, L. Ripoll, I. Rivilla, Y. Rodríguez García, J. Rodríguez, C. Rogero, L. Rogers, B. Romeo, C. Romo-Luque, F.P. Santos, J.M.F. dos Santos, A. Simón, M. Sorel, C. Stanford, J.M.R. Teixeira, P. Thapa, J.F. Toledo, J. Torrent, A. Usón, J.F.C.A. Veloso, R. Webb, R. Weiss-Babai, J.T. White, N. Yahlali, Texas A&M University, Department of Energy (US), National Science Foundation (US), Welch Foundation, Austrian Science Fund, European Commission, European Research Council, Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Fundación 'la Caixa', Ministerio de Ciencia, Innovación y Universidades (España), Generalitat Valenciana, Fundação para a Ciência e a Tecnologia (Portugal), Pazy foundation, and Argonne National Laboratory (US)
Subjects: Nuclear and High Energy Physics, Instrumentation
Abstract: NEXT Collaboration: et al., Radio-frequency (RF) carpets with ultra-fine pitches are examined for ion transport in gases at atmospheric pressures and above. We develop new analytic and computational methods for modeling RF ion transport at densities where dynamics are strongly influenced by buffer gas collisions. An analytic description of levitating and sweeping forces from phased arrays is obtained, then thermodynamic and kinetic principles are used to calculate ion loss rates in the presence of collisions. This methodology is validated against detailed microscopic SIMION simulations. We then explore a parameter space of special interest for neutrinoless double beta decay experiments: transport of barium ions in xenon at pressures from 1 to 10 bar. Our computations account for molecular ion formation and pressure dependent mobility as well as finite temperature effects. We discuss the challenges associated with achieving suitable operating conditions, which lie beyond the capabilities of existing devices, using presently available or near-future manufacturing techniques., The University of Texas at Arlington NEXT group is supported by the Department of Energy, USA under Early Career Award number DE-SC0019054 (BJPJ), by Department of Energy, USA Award DE-SC0019223 (DRN), the National Science Foundation, USA under award number NSF CHE 2004111 (FWF), and the Robert A Welch Foundation, Y-2031-20200401 (FWF). The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union’s Framework Programme for Research and Innovation Horizon 2020 (2014–2020) under the Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economía Competitividad and the Ministerio de Ciencia, Innovación Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program grants SEV-2014-0398 and CEX2018-000867-S, and the María de Maeztu Program MDM-2016-0692; from Fundacion Bancaria la Caixa (ID 100010434), grant code LCF/BQ/PI19/11690012; the Generalitat Valenciana of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014 and under projects UID/FIS/04559/2020 to fund the activities of LIBPhys-UC; the Pazy Foundation (Israel) under grants 877040 and 877041; the US Department of Energy under contracts number DE-AC02-06CH11357 (Argonne National Laboratory, USA), DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M). DGD acknowledges support from the Ramón y Cajal program (Spain) under contract number RYC-2015-18820. JM-A acknowledges support from Fundación Bancaria la Caixa (ID 100010434), grant code LCF/BQ/PI19/11690012, and from the Plan GenT program of the Generalitat Valenciana , grant code CIDEGENT/2019/049.
Published: 2022

11. Boosting background suppression in the NEXT experiment through Richardson-Lucy deconvolution

Author: Javier Pérez, Javier Rodríguez, T. Contreras, C. Newhouse, Marta Losada, T.T. Vuong, L. Rogers, A.A. Denisenko, K. Woodruff, S. Cebrián, N. López-March, K. Hafidi, R. C. Webb, J.V. Carrión, J. Torrent, J. M. Benlloch-Rodríguez, L. Ripoll, J.T. White, P. Lebrun, B. J. P. Jones, J. Muñoz Vidal, R.D.P. Mano, Iván Rivilla, F. Monrabal, B. Aparicio, A.B. Redwine, Y. Ifergan, C.A.O. Henriques, F.P. Cossío, I.J. Arnquist, J. Ho, R. Guenette, Z.-E. Meziani, J.F. Toledo, B. Palmeiro, Kevin Bailey, C. Adams, A.D. McDonald, N. Byrnes, S. Cárcel, R. Felkai, A.I. Aranburu, J.A. Hernando Morata, J. S. Díaz, M. Martínez-Vara, P. Novella, L.M.P. Fernandes, J.M.R. Teixeira, J. Martín-Albo, J.J. Gómez-Cadenas, C. Stanford, J. Escada, F.P. Santos, C.D.R. Azevedo, F.I.G.M. Borges, E. Oblak, A. Para, A. Usón, R. González, M. Querol, P. Herrero, M. Sorel, J.F.C.A. Veloso, E.D.C. Freitas, C.A.N. Conde, Luis Labarga, C.M.B. Monteiro, A.L. Ferreira, H. Almazán, Zoraida Freixa, A. Goldschmidt, J. Hauptman, Ana Martínez, Diego González-Díaz, Y. Rodriguez Garcia, J.M.F. dos Santos, J. Haefner, Víctor H. Alvarez, Lior Arazi, Frank W. Foss, Roberto Gutiérrez, V. Herrero, E. Church, N. Yahlali, C. Romo-Luque, Romain Esteve, F. Ballester, S. Gosh, Paola Ferrario, D. R. Nygren, M. Kekic, A. Laing, M. Odriozola-Gimeno, P. Thapa, J. Generowicz, R. Weiss-Babai, J. Renner, G. Díaz, G. Martínez-Lema, B. Romeo, F.J. Mora, Celia Rogero, A. Simón, and European Commission
Subjects: Nuclear and High Energy Physics, Ionization, Physics - Instrumentation and Detectors, Ionització, FOS: Physical sciences, double beta decay, Richardson–Lucy deconvolution, Bragg peak, Electron, QC770-798, 01 natural sciences, Signal, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Double beta decay, Nuclear and particle physics. Atomic energy. Radioactivity, gas, 0103 physical sciences, 010306 general physics, Physics, 010308 nuclear & particles physics, Raigs beta -- Desintegració, Instrumentation and Detectors (physics.ins-det), Computational physics, dark matter and double beta decay (experiments), Beta rays -- Decay, Deconvolution, Energy (signal processing)
Abstract: The NEXT collaboration: et al., Next-generation neutrinoless double beta decay experiments aim for half-life sensitivities of ∼ 1027 yr, requiring suppressing backgrounds to < 1 count/tonne/yr. For this, any extra background rejection handle, beyond excellent energy resolution and the use of extremely radiopure materials, is of utmost importance. The NEXT experiment exploits differences in the spatial ionization patterns of double beta decay and single-electron events to discriminate signal from background. While the former display two Bragg peak dense ionization regions at the opposite ends of the track, the latter typically have only one such feature. Thus, comparing the energies at the track extremes provides an additional rejection tool. The unique combination of the topology-based background discrimination and excellent energy resolution (1% FWHM at the Q-value of the decay) is the distinguishing feature of NEXT. Previous studies demonstrated a topological background rejection factor of ∼ 5 when reconstructing electron-positron pairs in the 208Tl 1.6 MeV double escape peak (with Compton events as background), recorded in the NEXT-White demonstrator at the Laboratorio Subterráneo de Canfranc, with 72% signal efficiency. This was recently improved through the use of a deep convolutional neural network to yield a background rejection factor of ∼ 10 with 65% signal efficiency. Here, we present a new reconstruction method, based on the Richardson-Lucy deconvolution algorithm, which allows reversing the blurring induced by electron diffusion and electroluminescence light production in the NEXT TPC. The new method yields highly refined 3D images of reconstructed events, and, as a result, significantly improves the topological background discrimination. When applied to real-data 1.6 MeV e−e+ pairs, it leads to a background rejection factor of 27 at 57% signal efficiency.
Published: 2021

12. Sensitivity of the NEXT experiment to Xe-124 double electron capture

Author: C.M.B. Monteiro, J.F.C.A. Veloso, G. Díaz, E.D.C. Freitas, B. Palmeiro, Y. Rodriguez Garcia, R. Weiss-Babai, J. Muñoz Vidal, F.P. Santos, Saunab Ghosh, Sandra K. Johnston, J.T. White, F. Ballester, J. Renner, Lior Arazi, J. Generowicz, A.B. Redwine, P. Herrero, V. Herrero, G. Martínez-Lema, J.M. Benlloch-Rodríguez, Paola Ferrario, A. Goldschmidt, J. Hauptman, L. Ripoll, B. J. P. Jones, J. S. Díaz, M. Martínez-Vara, P. Novella, F. Monrabal, J. Martín-Albo, J.J. Gómez-Cadenas, I.J. Arnquist, N. López-March, C.D.R. Azevedo, Kevin Bailey, A.D. McDonald, C. Adams, N. Byrnes, J. Torrent, Jose Repond, M. Kekic, S. Riordan, E. Church, R.D.P. Mano, T. Contreras, M. Querol, Javier Pérez, J.V. Carrión, C. Romo-Luque, L.M.P. Fernandes, B. Romeo, C. Sofka, C.A.O. Henriques, F.J. Mora, J.A. Hernando Morata, K. Woodruff, Jose A. Rodriguez, D. González-Díaz, L. Rogers, A. Usón, Marta Losada, C.A.N. Conde, Luis Labarga, T.M. Stiegler, A. Para, Víctor H. Alvarez, D. R. Nygren, F.I.G.M. Borges, A. Laing, J. Haefner, A. Simón, N. Yahlali, M. Sorel, A.F.M. Fernandes, P. Lebrun, S. Cebrián, Ana Martínez, A.L. Ferreira, Romain Esteve, R. C. Webb, M. Diesburg, R. Guenette, J. Escada, J.F. Toledo, S. Cárcel, K. Hafidi, J.M.F. dos Santos, Y. Ifergan, R. Felkai, Roberto Gutiérrez, and UAM. Departamento de Física Teórica
Subjects: Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Electron capture, Dark Matter and Double Beta Decay, Extrapolation, FOS: Physical sciences, chemistry.chemical_element, Electrons, Electron, 01 natural sciences, 7. Clean energy, Atomic, High Energy Physics - Experiment, TECNOLOGIA ELECTRONICA, Nuclear physics, High Energy Physics - Experiment (hep-ex), Xenon, Particle and Plasma Physics, Double beta decay, 0103 physical sciences, Nuclear Matrix, Nuclear, Sensitivity (control systems), Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Mathematical Physics, Physics, Quantum Physics, Isotope, 010308 nuclear & particles physics, Raigs beta -- Desintegració, Detector, Física, Molecular, Detectors, Instrumentation and Detectors (physics.ins-det), Beta Decay, Nuclear & Particles Physics, chemistry, 13. Climate action, Beta rays -- Decay
Abstract: [EN] Double electron capture by proton-rich nuclei is a second-order nuclear process analogous to double beta decay. Despite their similarities, the decay signature is quite di erent, potentially providing a new channel to measure the hypothesized neutrinoless mode of these decays. The Standard-Model-allowed two-neutrino double electron capture has been predicted for a number of isotopes, but only observed in 78Kr, 130Ba and, recently, 124Xe. The sensitivity to this decay establishes a benchmark for the ultimate experimental goal, namely the potential to discover also the lepton-number-violating neutrinoless version of this process. Here we report on the current sensitivity of the NEXT-White detector to 124Xe 2 ECEC and on the extrapolation to NEXT-100. Using simulated data for the 2 ECEC signal and real data from NEXT-White operated with 124Xe-depleted gas as background, we de ne an optimal event selection that maximizes the NEXT-White sensitivity. We estimate that, for NEXT-100 operated with xenon gas isotopically enriched with 1 kg of 124Xe and for a 5-year run, a sensitivity to the two-neutroni double electron capture half-life of 6x10exp22 years (at 90% con dence level) or better can be reached., The NEXT collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Sklodowska-Curie Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad and the Ministerio de Ciencia, Innovacion y Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program grants SEV-2014-0398 and CEX2018-000867-S, and the Maria de Maeztu Program MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014, under project UID/FIS/04559/2013 to fund the activities of LIBPhys, and under grants PD/BD/105921/2014, SFRH/BPD/109180/2015 and SFRH/BPD/76842/2011; the U.S. Department of Energy under contracts number DE-AC02-06CH11357 (Argonne National Laboratory), DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0019223/DE-SC0019054 (University of Texas at Arlington); and the University of Texas at Arlington. DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC-2015-18820. We also warmly acknowledge the Laboratori Nazionali del Gran Sasso (LNGS) and the Dark Side collaboration for their help with TPB coating of various parts of the NEXT-White TPC. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment
Published: 2021

13. Dependence of polytetrafluoroethylene reflectance on thickness at visible and ultraviolet wavelengths in air

Author: B. J. P. Jones, A. Usón, Víctor H. Alvarez, G. Martínez-Lema, R. Weiss-Babai, J.F.C.A. Veloso, E.D.C. Freitas, A.B. Redwine, J. Renner, F. Ballester, Kevin Bailey, A.D. McDonald, K. Hafidi, J. Torrent, J. S. Díaz, M. Martínez-Vara, P. Novella, A. Goldschmidt, J. Hauptman, P. Herrero, D. R. Nygren, L.M.P. Fernandes, J. Martín-Albo, J.J. Gómez-Cadenas, Paola Ferrario, Y. Ifergan, N. Yahlali, T. Contreras, B. Romeo, L. Rogers, K. Woodruff, D. González-Díaz, Saunab Ghosh, Marta Losada, E. Church, X. Li, Lior Arazi, J.M.F. dos Santos, Romain Esteve, Javier Pérez, J. M. Benlloch-Rodríguez, F.J. Mora, G. Díaz, S. Riordan, J. Haefner, C. Romo-Luque, C.A.O. Henriques, F.P. Santos, Jose Repond, R. Felkai, A. Simón, J. Muñoz Vidal, P. Lebrun, J.V. Carrión, C.D.R. Azevedo, A.F.M. Fernandes, M. Diesburg, Jorge Luis Rodriguez, F. Monrabal, C.A.N. Conde, Luis Labarga, T.M. Stiegler, J. Escada, N. López-March, B. Palmeiro, C. Burch, A. Laing, R. Guenette, J.F. Toledo, S. Cárcel, Roberto Gutiérrez, R.D.P. Mano, A. Para, S. Cebrián, Ana Martínez, F.I.G.M. Borges, M. Sorel, I.J. Arnquist, J.A. Hernando Morata, A.L. Ferreira, M. Querol, C. Adams, N. Byrnes, R. C. Webb, A. Loya Villalpando, V. Herrero, M. Kekic, J.T. White, C.M.B. Monteiro, Y. Rodriguez Garcia, and L. Ripoll
Subjects: Physics - Instrumentation and Detectors, FOS: Physical sciences, Library science, 7. Clean energy, 01 natural sciences, 030218 nuclear medicine & medical imaging, Synthetic materials, TECNOLOGIA ELECTRONICA, 03 medical and health sciences, 0302 clinical medicine, Political science, 0103 physical sciences, media_common.cataloged_instance, European union, Instrumentation, Ultraviolet radiation, Mathematical Physics, media_common, 010308 nuclear & particles physics, European research, Time projection Chambers (TPC), Instrumentation and Detectors (physics.ins-det), Visible radiation, Double-beta decay detectors, Reflectivity, Detector design and construction technologies and materials, National laboratory
Abstract: [EN] Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. However, the reflectance of PTFE is a function of its thickness. In this work, we investigate this dependence in air for light of wavelengths 260 nm and 450 nm using two complementary methods. We find that PTFE reflectance for thicknesses from 5 mm to 10 mm ranges from 92.5% to 94.5% at 450 nm, and from 90.0% to 92.0% at 260 nm We also see that the reflectance of PIFE of a given thickness can vary by as much as 2.7% within the same piece of material. Finally, we show that placing a specular reflector behind the PTFE can recover the loss of reflectance in the visible without introducing a specular component in the reflectance., The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad and the Ministerio de Ciencia, Innovacion y Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program grants SEV-2014-0398 and CEX2018-000867-S, and the Maria de Maeztu Program MDM-2016-0692; the Generalitat Valenciana under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014 and under projects UID/04559/2020 to fund the activities of LIBPhys-UC; the U.S. Department of Energy under contracts No. DE-AC02-06CH11357 (Argonne National Laboratory), DE-AC0207CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0019223/DE-SC0019054 (University of Texas at Arlington); and the University of Texas at Arlington (USA). DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC2015-18820. JM-A acknowledges support from Fundacion Bancaria "la Caixa" (ID 100010434), grant code LCF/BQ/PI19/11690012. Finally, we thank Brendon Bullard, Paolo Giromini and Neeraj Tata for helpful discussions and assistance with preliminary measurements.
Published: 2020

14. Radio frequency and DC high voltage breakdown of high pressure helium, argon, and xenon

Author: C.D.R. Azevedo, J.F.C.A. Veloso, E.D.C. Freitas, R. Guenette, A. Para, Sandra K. Johnston, J.F. Toledo, S. Cárcel, F.P. Santos, F.J. Mora, C.A.N. Conde, Luis Labarga, G. Martínez-Lema, P. Lebrun, M. Sorel, Jose A. Rodriguez, A. Martínez, Roberto Gutiérrez, T.M. Stiegler, A. Usón, A.L. Ferreira, Saunab Ghosh, Jose Repond, J.V. Carrión, Víctor H. Alvarez, J.M. Benlloch-Rodríguez, Lior Arazi, T. Contreras, A.A. Denisenko, A. Simón, J.M.F. dos Santos, B. Romeo, M. Querol, S. Riordan, F.I.G.M. Borges, E. Church, J.T. White, L. Norman, J. Muñoz Vidal, D. González-Díaz, C.A.O. Henriques, J. Haefner, Kevin Bailey, J. Baeza-Rubio, L.M.P. Fernandes, G. Díaz, A.D. McDonald, S. Cebrián, L. Ripoll, N. López-March, B. J. P. Jones, D. Huerta, R. C. Webb, Frank W. Foss, Marta Losada, M. Diesburg, A.F.M. Fernandes, C. Sofka, L. Rogers, M. Kekic, F. Monrabal, J. Escada, K. Hafidi, J. Torrent, R.D.P. Mano, C.M.B. Monteiro, R. Felkai, Javier Pérez, A. Goldschmidt, Y. Rodriguez Garcia, J. Hauptman, K. Woodruff, P. Herrero, J.A. Hernando Morata, I.J. Arnquist, J. S. Díaz, P. Novella, C. Adams, N. Byrnes, J. Martín-Albo, J.J. Gómez-Cadenas, B. Palmeiro, V. Herrero, N. Yahlali, Romain Esteve, A. Laing, D. R. Nygren, J. Generowicz, F. Ballester, Paola Ferrario, P. Thapa, C. Romo-Luque, R. Weiss-Babai, and J. Renner
Subjects: Materials science, Physics - Instrumentation and Detectors, chemistry.chemical_element, FOS: Physical sciences, Dielectric, 01 natural sciences, 030218 nuclear medicine & medical imaging, TECNOLOGIA ELECTRONICA, 03 medical and health sciences, Gaseous detectors, 0302 clinical medicine, Xenon, 0103 physical sciences, Nuclear Experiment (nucl-ex), Instrumentation, Nuclear Experiment, Mathematical Physics, Helium, Argon, Dielectric strength, 010308 nuclear & particles physics, High voltage, Instrumentation and Detectors (physics.ins-det), Gaseous imaging and tracking detectors, chemistry, Radio frequency, Atomic physics, Voltage
Abstract: Motivated by the possibility of guiding daughter ions from double beta decay events to single-ion sensors for barium tagging, the NEXT collaboration is developing a program of R&D to test radio frequency (RF) carpets for ion transport in high pressure xenon gas. This would require carpet functionality in regimes at higher pressures than have been previously reported, implying correspondingly larger electrode voltages than in existing systems. This mode of operation appears plausible for contemporary RF-carpet geometries due to the higher predicted breakdown strength of high pressure xenon relative to low pressure helium, the working medium in most existing RF carpet devices. In this paper we present the first measurements of the high voltage dielectric strength of xenon gas at high pressure and at the relevant RF frequencies for ion transport (in the 10 MHz range), as well as new DC and RF measurements of the dielectric strengths of high pressure argon and helium gases at small gap sizes. We find breakdown voltages that are compatible with stable RF carpet operation given the gas, pressure, voltage, materials and geometry of interest.
Published: 2020

15. Electron drift and longitudinal diffusion in high pressure xenon-helium gas mixtures

Author: Jose Repond, F.J. Mora, T.M. Stiegler, J. Pérez, I. J. Arnquist, C. Romo-Luque, C.A.N. Conde, A. Simón, C.M.B. Monteiro, J.M. Benlloch-Rodríguez, K. Hafidi, M. Kekic, A. Para, Y. Rodriguez Garcia, D. González-Díaz, M. Sorel, A.L. Ferreira, A.D. McDonald, G. Díaz, N. Yahlali, M. Querol, M. Losada, J. Muñoz Vidal, Sandra K. Johnston, D.R. Nygren, Romain Esteve, B. Al Atoum, B. Palmeiro, E. Church, C.D.R. Azevedo, G. Martínez-Lema, C. Sofka, J. Generowicz, F.I.G.M. Borges, M. Diesburg, K. Woodruff, L. Ripoll, J.T. White, V. Herrero, B. J. P. Jones, J. Haefner, J. Escada, B. Romeo, R. Felkai, F. Ballester, Roberto Gutiérrez, R. Weiss-Babai, J. S. Díaz, P. Novella, J. Renner, J. Martín-Albo, J.J. Gómez-Cadenas, L.M.P. Fernandes, R. Guenette, P. Herrero, A. Laing, J.F. Toledo, S. Cárcel, S. Riordan, P. Lebrun, A. Martínez, S. Cebrián, R. C. Webb, J.M.F. dos Santos, Paola Ferrario, C.A.O. Henriques, A. Goldschmidt, J. Hauptman, J. Torrent, K. Bailey, F.P. Santos, Javier Rodríguez, L. Rogers, A. Usón, Víctor H. Alvarez, J.F.C.A. Veloso, E.D.C. Freitas, Lior Arazi, F. Monrabal, J. V. Carrión, N. López-March, R.D.P. Mano, J.A. Hernando Morata, C. Adams, A.F.M. Fernandes, L. Labarga, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, and Generalitat Valenciana
Subjects: Physics - Instrumentation and Detectors, Materials science, Drift velocity, Physics::Instrumentation and Detectors, Extrapolation, FOS: Physical sciences, chemistry.chemical_element, Electron, 01 natural sciences, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Xenon, Electric field, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Nuclear Experiment (nucl-ex), Diffusion (business), Nuclear Experiment, Instrumentation, Mathematical Physics, Helium, 010308 nuclear & particles physics, Instrumentation and Detectors (physics.ins-det), chemistry, Atomic physics, Bar (unit)
Abstract: We report new measurements of the drift velocity and longitudinal diffusion coefficients of electrons in pure xenon gas and in xenon-helium gas mixtures at 1-9 bar and electric field strengths of 50-300 V/cm. In pure xenon we find excellent agreement with world data at all $E/P$, for both drift velocity and diffusion coefficients. However, a larger value of the longitudinal diffusion coefficient than theoretical predictions is found at low $E/P$ in pure xenon, below the range of reduced fields usually probed by TPC experiments. A similar effect is observed in xenon-helium gas mixtures at somewhat larger $E/P$. Drift velocities in xenon-helium mixtures are found to be theoretically well predicted. Although longitudinal diffusion in xenon-helium mixtures is found to be larger than anticipated, extrapolation based on the measured longitudinal diffusion coefficients suggest that the use of helium additives to reduce transverse diffusion in xenon gas remains a promising prospect.
Published: 2019

16. Mitigation of backgrounds from cosmogenic 137 Xe in xenon gas experiments using 3 He neutron capture

Author: A. Usón, Víctor H. Alvarez, L. Labarga, J. Torrent, Sandra K. Johnston, K. Bailey, J. Haefner, M. Sorel, R.D.P. Mano, P. Lebrun, T. Contreras, C.A.O. Henriques, P. Herrero, Y. Ifergan, J. Generowicz, A.L. Ferreira, Javier Rodríguez, G. Díaz, J.F.C.A. Veloso, E.D.C. Freitas, B. Palmeiro, M. Diesburg, M. Querol, Jose Repond, J. Escada, F.J. Mora, J. M. Benlloch-Rodríguez, J.V. Carrión, L. Rogers, F. Monrabal, Lior Arazi, Javier Pérez, C.M.B. Monteiro, C. Adams, T.M. Stiegler, Diego González-Díaz, G. Martínez-Lema, Y. Rodriguez Garcia, J. A. Hernando Morata, R. Felkai, L.M.P. Fernandes, A.F.M. Fernandes, A. Goldschmidt, C. Sofka, Sudip Ghosh, S. Cebrián, B. Romeo, M. Kekic, C.D.R. Azevedo, E. Church, C.A.N. Conde, P. Novella, A.B. Redwine, F.I.G.M. Borges, R. M. Gutiérrez, J. Martín-Albo, N. Lopez-March, R. C. Webb, J.J. Gómez-Cadenas, N. Byrnes, F.P. Santos, A.D. McDonald, J. Muñoz Vidal, K. Woodruff, D. R. Nygren, R. Weiss-Babai, J. T. White, J. Renner, J. M. Hauptman, A. Laing, N. Yahlali, Romain Esteve, M. Losada, R. Dingler, V. Herrero, F. Ballester, Paola Ferrario, I. J. Arnquist, R. Guenette, B. Smithers, J.F. Toledo, S. Cárcel, S. Riordan, A. Martínez, L. Ripoll, B. J. P. Jones, S. Pingulkar, J.M.F. dos Santos, J. Díaz, A. Para, K. Hafidi, A. Simón, C. Romo-Luque, and UAM. Departamento de Física Teórica
Subjects: Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Scintillation and light emission processes, Gas and liquid scintillators, FOS: Physical sciences, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, TECNOLOGIA ELECTRONICA, Nuclear physics, Gaseous detectors, Solid, High Energy Physics - Experiment (hep-ex), Xenon, Double beta decay, 0103 physical sciences, Isotopes of xenon, Spallation, Neutron, 010306 general physics, Physics, 010308 nuclear & particles physics, Física, Instrumentation and Detectors (physics.ins-det), Beta Decay, Neutron temperature, Neutron capture, chemistry, Scintillators, Radioactive decay
Abstract: [EN] Xe-136 is used as the target medium for many experiments searching for 0 nu beta beta. Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of Xe-137 created by the capture of neutrons on Xe-136. This isotope decays via beta decay with a half-life of 3.8 min and a Q(beta) of similar to 4.16 MeV. This work proposes and explores the concept of adding a small percentage of He-3 to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we find the contamination from Xe-137 activation can be reduced to negligible levels in tonne and multi-tonne scale high pressure gas xenon neutrinoless double beta decay experiments running at any depth in an underground laboratory., The work described was supported by the Department of Energy under Award numbers DE-SC0019054 and DE-SC0019223. The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Program for Research and Innovation Horizon 2020 (2014-2020) under the Marie Skodowska-Curie Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad of Spain under grants FIS2014-53371-C04, the Severo Ochoa Program SEV-2014-0398 and the Maria de Maetzu Program MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014, under project UID/FIS/04559/2013 to fund the activities of LIBPhys, and under grants PD/BD/105921/2014, SFRH/BPD/109180/2015 and SFRH/BPD/76842/2011. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment.
Published: 2020

17. Search for Rare and Forbidden Charm Meson DecaysD0→Vℓ+ℓ−andhhℓℓ

Author: K. O'Shaughnessy, dos Reis Ac, K. C. Peng, A. K. Tripathi, S. M. Yang, N. R. Stanton, Alberto Santoro, A. J. Slaughter, A. Nguyen, P.A. Kasper, S. Yoshida, A. Napier, K. Denisenko, S. B. Bracker, A. Álvarez Fernández, M. Sheaff, S. Amato, D. Yi, D. C. Langs, R. Weiss-Babai, R. A. Burnstein, L. M. Cremaldi, E. Wolin, G. F. Fox, B. Quinn, A.B. d'Oliveira, A. Rafatian, E.M. Aitala, C. James, N. W. Reay, J. Leslie, N. Witchey, S. Takach, G. Hurvits, C. Zhang, S. Watanabe, de Mello Neto, M. V. Purohit, B. Lundberg, R. H. Milburn, H.S. Carvalho, A.K.S. Santha, A.M. Halling, S. Banerjee, Kevin Stenson, J. C. Anjos, J. A. Appel, R. A. Sidwell, J. Magnin, Sokoloff, R. Zaliznyak, D. J. Summers, K. Gounder, Daniel Ashery, T. Carter, A. J. Schwartz, D. A. Sanders, L. Perera, G. Blaylock, G. Herrera, K. Thorne, Simon Kwan, D. Mihalcea, S. Devmal, H. A. Rubin, S. Radeztsky, P. Gagnon, C. L. Darling, R. J. Stefanski, N. K. Copty, J. Solano, J. Wiener, J.J. Reidy, C. Göbel, S. MayTal-Beck, de Miranda Jm, B. T. Meadows, P. R. Burchat, and I. Bediaga
Subjects: Physics, Particle physics, Antiparticle, Muon, Meson, Neutral current, High Energy Physics::Phenomenology, General Physics and Astronomy, Nuclear physics, Pseudoscalar, High Energy Physics::Experiment, Vector meson, Charm (quantum number), Lepton
Abstract: We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the ${D}^{0}$ (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a ${\ensuremath{\rho}}^{0}$, ${\overline{K}}^{*0}$, or $\ensuremath{\varphi}$ vector meson or a nonresonant $\ensuremath{\pi}\ensuremath{\pi}$, $K\ensuremath{\pi}$, or $\mathrm{KK}$ pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).
Published: 2001

18. Study of theDs+→π−π+π+Decay and Measurement off0Masses and Widths

Author: G. F. Fox, D. J. Summers, K. Gounder, J. M. De Miranda, B. T. Meadows, M. D. Sokoloff, J. R. T. de Mello Neto, P.A. Kasper, S. B. Bracker, S. Radeztsky, S. Watanabe, J.J. Reidy, M. Sheaff, R. J. Stefanski, S. Devmal, R. A. Sidwell, S. Takach, B. Lundberg, I. Bediaga, C. Zhang, A. J. Slaughter, J. A. Appel, A. Napier, Daniel Ashery, K. Denisenko, P. Gagnon, A.M. Halling, D. Yi, K. C. Peng, H.S. Carvalho, S. M. Yang, A. Nguyen, A. Massafferri, H. A. Rubin, N. K. Copty, S. MayTal-Beck, R. Zaliznyak, Simon Kwan, S. Yoshida, A. K. Tripathi, D. C. Langs, M. V. Purohit, C. L. Darling, K. O'Shaughnessy, G. Blaylock, A.K.S. Santha, J. Solano, C. James, S. Amato, A.B. d'Oliveira, E.M. Aitala, Alberto Santoro, J. C. Anjos, N. W. Reay, J. Leslie, J. Magnin, D. A. Sanders, J. Wiener, L. Perera, D. Mihalcea, A. C. dos Reis, R. Weiss-Babai, A. Álvarez Fernández, L. M. Cremaldi, K. Thorne, Patricia R. Burchat, E. Wolin, S. Banerjee, N. Witchey, C. Göbel, A. J. Schwartz, R. H. Milburn, R. A. Burnstein, N. R. Stanton, A. Rafatian, G. Hurvits, Kevin Stenson, G. Herrera, T. Carter, and B. Quinn
Subjects: Physics, Crystallography, Particle physics, Pi, General Physics and Astronomy, Dalitz plot
Abstract: From a sample of $848\ifmmode\pm\else\textpm\fi{}44$ ${D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ decays, we find $\ensuremath{\Gamma}({D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+})/\ensuremath{\Gamma}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.245\ifmmode\pm\else\textpm\fi{}{0.028}_{\ensuremath{-}0.012}^{+0.019}$. Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels ${\ensuremath{\rho}}^{0}(770){\ensuremath{\pi}}^{+}$, ${\ensuremath{\rho}}^{0}(1450){\ensuremath{\pi}}^{+}$, ${f}_{0}(980){\ensuremath{\pi}}^{+}$, ${f}_{2}(1270){\ensuremath{\pi}}^{+}$, and ${f}_{0}(1370){\ensuremath{\pi}}^{+}$. We also present the values obtained for masses and widths of the resonances ${f}_{0}(980)$ and ${f}_{0}(1370)$.
Published: 2001

19. Experimental Evidence for a Light and Broad Scalar Resonance inD+→π−π+π+Decay

Author: N. R. Stanton, N. Witchey, D.C. Langs, S. Radeztsky, S. MayTal-Beck, A. Nguyen, Alberto Santoro, Kevin Stenson, J. Magnin, A.K. Tripathi, A.M. Halling, D. J. Summers, K. Gounder, R. H. Milburn, I. Bediaga, C. Zhang, R. A. Burnstein, J. A. Appel, G. F. Fox, S. M. Yang, S. Yoshida, P.A. Kasper, J.J. Reidy, A. Massafferri, A. Rafatian, J. Wiener, R. J. Stefanski, G. Blaylock, A. Napier, H.S. Carvalho, B. Lundberg, de Miranda Jm, K. Denisenko, D. Yi, Sokoloff, N. W. Reay, J. Leslie, G. Hurvits, C. Göbel, S. Takach, S. Watanabe, R. Weiss-Babai, B. T. Meadows, Daniel Ashery, M. Sheaff, C. L. Darling, S. B. Bracker, D. A. Sanders, A. J. Schwartz, Simon Kwan, Sudeshna Banerjee, J. C. Anjos, T. Carter, G. Herrera, P. Gagnon, C. James, R. Zaliznyak, N. K. Copty, S. Amato, B. Quinn, H. A. Rubin, de Mello Neto, J. Solano, D. Mihalcea, A. J. Slaughter, M. V. Purohit, A.K.S. Santha, K. O'Shaughnessy, dos Reis Ac, S. Devmal, L.P. Perera, R. A. Sidwell, Patricia R. Burchat, A.B. d'Oliveira, E.M. Aitala, A. Álvarez Fernández, L. M. Cremaldi, E. Wolin, K. C. Peng, and K. Thorne
Subjects: Physics, Nuclear magnetic resonance, Amplitude, Scalar (mathematics), Analytical chemistry, Pi, General Physics and Astronomy, Dalitz plot, Resonance
Abstract: From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.
Published: 2001

20. Asymmetries in the production of Λc+ and Λc− baryons in 500 GeV/c π− nucleon interactions

Author: S. M. Yang, R. A. Burnstein, Kevin Stenson, S. Yoshida, A. Rafatian, C. Zhang, H.S. Carvalho, N. Witchey, M. V. Purohit, A. Nguyen, K. C. Peng, A.B. d'Oliveira, A. Fernandez, D.C. Langs, S. MayTal-Beck, B. Quinn, J. R. T. de Mello Neto, A.K.S. Santha, E.M. Aitala, A. Napier, K. Denisenko, D. Yi, R. Weiss-Babai, G. Hurvits, R. A. Sidwell, D. A. Sanders, R. J. Stefanski, N. K. Copty, A.K. Tripathi, I. Bediaga, G. Blaylock, K. Thorne, J. C. Anjos, A. J. Slaughter, T. Carter, L. M. Cremaldi, E. Wolin, D. Mihalcea, S. B. Bracker, N. R. Stanton, F.R.A. Simão, A. C. dos Reis, J. Magnin, A. J. Schwartz, C. L. Darling, J.J. Reidy, B. Lundberg, B. T. Meadows, R. Zaliznyak, M. Sheaff, M. D. Sokoloff, G. Herrera, P.A. Kasper, Sudeshna Banerjee, S. Devmal, P. R. Burchat, D. J. Summers, R. H. Milburn, L.P. Perera, K. Gounder, K. O'Shaughnessy, J. M. De Miranda, Alberto Santoro, J. Solano, Daniel Ashery, S. Amato, G. F. Fox, H. A. Rubin, S. Takach, S. Radeztsky, S. Watanabe, A.M. Halling, Simon Kwan, P. Gagnon, C. James, J. A. Appel, N. W. Reay, J. Leslie, J. Wiener, and C. Göbel
Subjects: Physics, Nuclear and High Energy Physics, media_common.quotation_subject, Lambda, Asymmetry, Baryon, Nuclear physics, symbols.namesake, Pi, symbols, Feynman diagram, Production (computer science), Fermilab, Nucleon, media_common
Abstract: We present a measurement of asymmetries in the production of Λ c + and Λ c − baryons in 500 GeV/ c π − -nucleon interactions from the E791 experiment at Fermilab. The asymmetries were measured as functions of Feynman x ( x F ) and transverse momentum squared ( p T 2 ) using a sample of 1 819±62 Λ c 's observed in the decay channel Λ c + → pK − π + . We observe more Λ c + than Λ c − baryons, with an asymmetry of (12.7±3.4±1.3)% independent of x F and p T 2 in our kinematical range (−0.1⩽ x F ⩽0.6 and 0.0⩽ p T 2 ⩽8.0 (GeV/ c ) 2 ). This Λ c asymmetry measurement is the first with data in both the positive and negative x F regions.
Published: 2000

21. Asymmetries in the production of Λ0, Ξ−, and hyperons in 500 GeV/c π−–nucleon interactions

Author: J. A. Appel, Michael Sokoloff, K. O'Shaughnessy, A. Napier, P.A. Kasper, A.B. d'Oliveira, E.M. Aitala, K. Denisenko, D. Yi, R. Weiss-Babai, C. James, R. Zaliznyak, S. Devmal, B. Quinn, G. Blaylock, A.J. Slaughter, A. J. Schwartz, C. L. Darling, S. Takach, A. Rafatian, L.P. Perera, K. C. Peng, S. B. Bracker, N. Witchey, J. R. T. de Mello Neto, J. Wiener, J.J. Reidy, G. Hurvits, Milind Purohit, I. Bediaga, Don Summers, A. Fernandez, D.C. Langs, R. A. Sidwell, B. Lundberg, C. Göbel, C. Zhang, A.K.S. Santha, L. M. Cremaldi, D. Ashery, E. Wolin, A. Nguyen, S. MayTal-Beck, H. A. Rubin, Kevin Stenson, M. Sheaff, N. R. Stanton, J. C. Anjos, T. Carter, A.K. Tripathi, R. H. Milburn, Alberto Santoro, F.R.A. Simão, N. K. Copty, Brian Meadows, Patricia R. Burchat, A. C. dos Reis, K. Thorne, J. Solano, G. Herrera, S. Yoshida, H.S. Carvalho, N. W. Reay, J. Leslie, Simon Kwan, David Sanders, P. Gagnon, K. Gounder, J. M. De Miranda, S. Radeztsky, A.M. Halling, J. Magnin, R.A. Burnstein, Sudeshna Banerjee, S. Amato, G. F. Fox, and S. Watanabe
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, media_common.quotation_subject, Astrophysics::Cosmology and Extragalactic Astrophysics, Asymmetry, Nuclear physics, Baryon, symbols.namesake, Transverse momentum, symbols, Feynman diagram, High Energy Physics::Experiment, Fermilab, Nuclear Experiment, Nucleon, media_common
Abstract: We present a measurement of asymmetries in the production of Λc+ and Λc− baryons in 500 GeV/c π−-nucleon interactions from the E791 experiment at Fermilab. The asymmetries were measured as functions of Feynman x (xF) and transverse momentum squared (pT2) using a sample of 1 819±62 Λc's observed in the decay channel Λc+→pK−π+. We observe more Λc+ than Λc− baryons, with an asymmetry of (12.7±3.4±1.3)% independent of xF and pT2 in our kinematical range (−0.1⩽xF⩽0.6 and 0.0⩽pT2⩽8.0 (GeV/c)2). This Λc asymmetry measurement is the first with data in both the positive and negative xF regions.
Published: 2000

22. Correlations between D and $${\overline D}$$ mesons produced in 500 GeV/cπ−-nucleon interactions

Author: D. Ashery, Patricia R. Burchat, S. Radeztsky, K. O'Shaughnessy, J. A. Appel, J.J. Reidy, H.S. Carvalho, A.M. Halling, K. Gounder, J. M. De Miranda, B. Lundberg, A.B. d'Oliveira, David Sanders, C. Göbel, E.M. Aitala, K. C. Peng, Kevin Stenson, G. Blaylock, Don Summers, C.J. Solano Salinas, L.P. Perera, R.A. Burnstein, K. Thorne, S. Takach, Milind Purohit, I. Bediaga, Sudeshna Banerjee, S. MayTal-Beck, L. M. Cremaldi, E. Wolin, J. R. T. de Mello Neto, A.K.S. Santha, A. Napier, K. Denisenko, S. Amato, D. Yi, A.J. Slaughter, A.K. Tripathi, R. Weiss-Babai, G. F. Fox, J. C. Anjos, H. A. Rubin, D. Mihalcea, R. A. Sidwell, S. Watanabe, A. Nguyen, B. Quinn, S. M. Yang, C. Zhang, A. C. dos Reis, R. J. Stefanski, S. Yoshida, T. Carter, N. Witchey, A. Fernandez, D.C. Langs, M. Sheaff, Sokoloff, N. K. Copty, N. R. Stanton, C. James, Stephen B. Bracker, J. Wiener, R. Zaliznyak, P.A. Kasper, Simon Kwan, P. Gagnon, N. W. Reay, J. Leslie, C. L. Darling, A. Rafatian, G. Hurvits, Alberto Santoro, Brian Meadows, R. H. Milburn, A. J. Schwartz, and G. Herrera
Subjects: Physics, Quantum chromodynamics, Particle physics, Meson, High Energy Physics::Phenomenology, Order (ring theory), Nuclear physics, D meson, High Energy Physics::Experiment, Production (computer science), Charm (quantum number), Nuclear Experiment, Nucleon, Event generator
Abstract: We present a study of correlations between D and $${\overline D}$$ mesons produced in 500 GeV/cπ−-nucleon interactions, based on data from experiment E791 at Fermilab. We have fully reconstructed 791 ± 44 charm meson pairs to study correlations between the transverse and longitudinal momenta of the two D mesons and the relative production rates for different types of D meson pairs. We see slight correlations between the longitudinal momenta of the D and the $${\bar D}$$ , and significant correlations between the azimuthal angle of the D and the $${\bar D}$$ . The experimental distributions are compared to a next-to-leading-order QCD calculation and to predictions of the PYTHIA/JETSET Monte Carlo event generator. We observe less correlation between transverse momenta and different correlations between longitudinal momenta than these models predict for the default values of the model parameters. Better agreement between data and theory might be achieved by tuning the model parameters or by adding higher order perturbative terms, thus contributing to a better understanding of charm production. The relative production rates for the four sets of charm pairs, $$D^0{{\overline D}^0}, D^0 D^{-}, D^+{{\overline D}^0}, D^+ D^{-}$$ as calculated in the PYTHIA/JETSET event generator with the default parameters, agree with data as far as the relative ordering, but predict too many $$D^+ {{\overline D}^0}$$ pairs and too few $$D^+ D^{-}$$ pairs.
Published: 2000

23. Multidimensional resonance analysis of Λc+→pK−π+

Author: E.M. Aitala, S. Amato, J.C. Anjos, J.A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S.B. Bracker, P.R. Burchat, R.A. Burnstein, T. Carter, H.S. Carvalho, N.K. Copty, L.M. Cremaldi, C. Darling, K. Denisenko, S. Devmal, A. Fernandez, G.F. Fox, P. Gagnon, C. Gobel, K. Gounder, A.M. Halling, G. Herrera, G. Hurvits, C. James, P.A. Kasper, S. Kwan, D.C. Langs, J. Leslie, B. Lundberg, J. Magnin, S. MayTal-Beck, B. Meadows, J.R.T. de Mello Neto, D. Mihalcea, R.H. Milburn, J.M. de Miranda, A. Napier, A. Nguyen, A.B. d'Oliveira, K. O'Shaughnessy, K.C. Peng, L.P. Perera, M.V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N.W. Reay, J.J. Reidy, A.C. dos Reis, H.A. Rubin, D.A. Sanders, A.K.S. Santha, A.F.S. Santoro, A.J. Schwartz, M. Sheaff, R.A. Sidwell, A.J. Slaughter, M.D. Sokoloff, J. Solano, N.R. Stanton, R.J. Stefanski, K. Stenson, D.J. Summers, S. Takach, K. Thorne, A.K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, S.M. Yang, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang
Subjects: Baryon, Physics, Nuclear and High Energy Physics, Particle physics, Amplitude, Resonance analysis, Pi, Resonance, Lambda, Bar (unit)
Abstract: We present the results of a five-dimensional resonant amplitude analysis of the $\Lambda_c^+{\to}pK^{-}\pi^{+}$ system based on $946\pm 38$ reconstructed decays. These data were produced in 500 GeV/$c$ $\pi^-$-N interactions by Fermilab experiment E791. We report measurements of the amplitudes for $\Lambda_c^+$ decay into nonresonant $pK^-\pi^+$ and to $p\bar{K}^{*0}(890)$, $\Delta^{++}(1232)K^-$, and $\Lambda(1520)\pi^+$ and we comment on other possible resonant enhancements. This is the first complete amplitude analysis of the $\Lambda_c^{+}{\to}pK^{-}\pi^{+}$ system. We find that $(54.8\pm5.5\pm3.5)$% of the decays are nonresonant, $(19.5\pm2.6\pm1.8)$% of the decays are via the $\bar{K}^{*0}$ resonance, $(18.0\pm2.9\pm2.9)$% of the decays are via the $\Delta^{++}$ resonance, and $(7.7\pm1.8\pm1.1)$% of the decays are via the $\Lambda(1520)$ resonance. We find evidence for an increasingly negative polarization of the $\Lambda_c^+$ baryons as a function of $p_T^2$, in agreement with a recent model\cite{dha} and with a related measurement\cite{jez}.
Published: 2000

24. Measurement of the form-factor ratios for D+s→φℓ+νℓ

Author: E.M. Aitala, S. Amato, J.C. Anjos, J.A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S.B. Bracker, P.R. Burchat, R.A. Burnstein, T. Carter, H.S. Carvalho, N.K. Copty, L.M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, G.F. Fox, P. Gagnon, C. Gobel, K. Gounder, A.M. Halling, G. Herrera, G. Hurvits, C. James, P.A. Kasper, S. Kwan, D.C. Langs, J. Leslie, B. Lundberg, S. MayTal-Beck, B. Meadows, J.R.T. de Mello Neto, D. Mihalcea, R.H. Milburn, J.M. de Miranda, A. Napier, A. Nguyen, A.B. d'Oliveira, K. O'Shaughnessy, K.C. Peng, L.P. Perera, M.V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N.W. Reay, J.J. Reidy, A.C. dos Reis, H.A. Rubin, D.A. Sanders, A.K.S. Santha, A.F.S. Santoro, A.J. Schwartz, M. Sheaff, R.A. Sidwell, A.J. Slaughter, M.D. Sokoloff, J. Solano, N.R. Stanton, R.J. Stefanski, K. Stenson, D.J. Summers, S. Takach, K. Thorne, A.K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, S.M. Yang, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Electron channel, Form factor (quantum field theory), Lepton
Abstract: We have measured the form factor ratios r_V = V(0)/A_1(0) and r_2 = A_2(0)/A_1(0) for the decay D_s^+ -> phi ell^+ nu_ell, phi -> K^+ K^-, using data from charm hadroproduction experiment E791 at Fermilab. Results are based on 144 signal and 22 background events in the electron channel and 127 signal and 34 background events in the muon channel. We combine the measurements from both lepton channels to obtain r_V = 2.27 +- 0.35 +- 0.22 and r_2 = 1.57 +- 0.25 +- 0.19.
Published: 1999

25. Search for the pentaquark via the decay

Author: R. Zaliznyak, Sudeshna Banerjee, A. Napier, K. Denisenko, T. Carter, J.J. Reidy, D. Yi, J. A. Appel, R. Weiss-Babai, S. Takach, L.P. Perera, A. J. Schwartz, S. Amato, S. Radeztsky, Simon Kwan, G. F. Fox, P.A. Kasper, N. Witchey, S. M. Yang, L. M. Cremaldi, I. Bediaga, E. Wolin, S. MayTal-Beck, A. Fernandez, S. Yoshida, D.C. Langs, S. Gerzon, A.K. Tripathi, G. Herrera, J. Lichtenstadt, S. Watanabe, D. J. Summers, K. Gounder, P. Gagnon, J. M. De Miranda, A. J. Slaughter, B. T. Meadows, M. D. Sokoloff, P. R. Burchat, K. O'Shaughnessy, Kevin Stenson, R. A. Sidwell, R. J. Stefanski, N. W. Reay, J. Leslie, S. B. Bracker, Alberto Santoro, B. Quinn, M. V. Purohit, A.M. Halling, J. C. Anjos, H.S. Carvalho, D. Mihalcea, A.K.S. Santha, J. R. T. de Mello Neto, E.M. Aitala, K. C. Peng, Daniel Ashery, R. A. Burnstein, B. Lundberg, A. C. dos Reis, A. Rafatian, G. Hurvits, H. A. Rubin, N. K. Copty, J. Solano, J. Wiener, C. Göbel, C. Zhang, C. James, M. Sheaff, A. Nguyen, D. A. Sanders, K. Thorne, G. Blaylock, R. H. Milburn, N. R. Stanton, A. B. D'Oliveira, and C. L. Darling
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Cross section (physics), Particle physics, Branching fraction, Fermilab, Beam (structure), Pentaquark
Abstract: We have searched for evidence of the production and decay of a neutral bound-state pentaquark, one of a predicted doublet of states: P 0 c s =| c suud〉 and P − c s =| c sddu〉 . Specifically, we have searched for the decay P 0 c s →K ∗0 K − p in data from Fermilab experiment E791, in which a 500 GeV/c π− beam interacted with nuclear targets. We find mass-dependent upper limits at the 90% confidence level for the ratio of cross section times branching fraction of this decay relative to that for the decay D s − →K ∗0 K − . The upper limits vary between 0.016 and 0.036 for M(P 0 c s ) between 2.75 and 2.91 GeV/c2, assuming a pentaquark lifetime of 0.4 ps.
Published: 1999

26. Measurement of the Ds lifetime

Author: E.M. Aitala, S. Amato, J.C. Anjos, J.A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S.B. Bracker, P.R. Burchat, R.A. Burnstein, T. Carter, H.S. Carvalho, N.K. Copty, L.M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, G.F. Fox, P. Gagnon, C. Gobel, K. Gounder, A.M. Halling, G. Herrera, G. Hurvits, C. James, P.A. Kasper, S. Kwan, D.C. Langs, J. Leslie, B. Lundberg, S. MayTal-Beck, B. Meadows, J.R.T. de Mello Neto, D. Mihalcea, R.H. Milburn, J.M. de Miranda, A. Napier, A. Nguyen, A.B. d'Oliveira, K. O'Shaughnessy, K.C. Peng, L.P. Perera, M.V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N.W. Reay, J.J. Reidy, A.C. dos Reis, H.A. Rubin, D.A. Sanders, A.K.S. Santha, A.F.S. Santoro, A.J. Schwartz, M. Sheaff, R.A. Sidwell, A.J. Slaughter, M.D. Sokoloff, J. Solano, N.R. Stanton, R.J. Stefanski, K. Stenson, D.J. Summers, S. Takach, K. Thorne, A.K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, S.M. Yang, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang
Subjects: Physics, High Energy Physics - Experiment (hep-ex), Nuclear and High Energy Physics, Particle physics, Meson, Maximum likelihood, FOS: Physical sciences, Charm (quantum number), Fermilab, Measure (mathematics), Standard deviation, High Energy Physics - Experiment
Abstract: We report the results of a precise measurement of the Ds meson lifetime based on 1662 +/- 56 fully reconstructed Ds -> phi pi decays, from the charm hadroproduction experiment E791 at Fermilab. Using an unbinned maximum likelihood fit, we measure the Ds lifetime to be 0.518 +/- 0.014 +/- 0.007 ps. The ratio of the measured Ds lifetime to the world average D0 lifetime is 1.25 +/- 0.04. This result differs from unity by six standard deviations, indicating significantly different lifetimes for the Ds and the D0., 12 pages, 3 figures, 2 table. LaTeX
Published: 1999

27. Measurement of the form-factor ratios for D→ℓν

Author: N. R. Stanton, S. Takach, A. Napier, K. Denisenko, D. Yi, R. Weiss-Babai, B. Lundberg, S. B. Bracker, S. M. Yang, S. Radeztsky, G. Blaylock, R. Zaliznyak, K. C. Peng, S. Yoshida, J.J. Reidy, Simon Kwan, J. R. T. de Mello Neto, R. H. Milburn, A.B. d'Oliveira, E.M. Aitala, P.A. Kasper, C. Zhang, D. C. Langs, D. J. Summers, K. Gounder, B. T. Meadows, A. Álvarez Fernández, J. M. De Miranda, Kevin Stenson, M. D. Sokoloff, L. M. Cremaldi, E. Wolin, S. MayTal-Beck, S. Amato, R. J. Stefanski, Pauline Gagnon, N. K. Copty, A. J. Slaughter, T. Carter, A. Nguyen, J. Wiener, R. A. Sidwell, S. Banerjee, C. Göbel, D. Mihalcea, C. James, A.M. Halling, J. A. Appel, A. C. dos Reis, M. V. Purohit, J. Solano, G. F. Fox, B. Quinn, D. A. Sanders, Daniel Ashery, I. Bediaga, A.K.S. Santha, S. Watanabe, N. W. Reay, J. Leslie, L. Perera, N. Witchey, C. L. Darling, K. Thorne, Patricia R. Burchat, R. A. Burnstein, A. Rafatian, G. Hurvits, K. O'Shaughnessy, Alberto Santoro, M. Sheaff, H. A. Rubin, H.S. Carvalho, J. C. Anjos, A. J. Schwartz, G. Herrera, and A. K. Tripathi
Subjects: Physics, Nuclear and High Energy Physics, chemistry, Analytical chemistry, chemistry.chemical_element, Platinum, Carbon
Published: 1998

28. Search for the Pentaquark via thePcs¯0→φπpDecay

Author: S. Yoshida, S. Banerjee, A. K. Tripathi, A. J. Slaughter, S. MayTal-Beck, A. Napier, J. C. Anjos, D. Yi, R. Weiss-Babai, S. Gerzon, N. R. Stanton, J. R. T. de Mello Neto, A. Nguyen, Daniel Ashery, C. James, B. Lundberg, J. Leslie, E.M. Aitala, B. T. Meadows, D. C. Langs, M. Sheaff, M. D. Sokoloff, P. R. Burchat, N. W. Reay, S. B. Bracker, J. A. Appel, P. Gagnon, S. Amato, H. A. Rubin, K. O'Shaughnessy, J. Lichtenstadt, I. Bediaga, H.S. Carvalho, G. Blaylock, R. H. Milburn, C. Zhang, Simon Kwan, R. Zaliznyak, T. Carter, A. B. d'Oliveira, J. Wiener, P.A. Kasper, N. K. Copty, J. J. Reidy, A. J. Schwartz, K. Denisenko, S. Takach, C. Göbel, A. K. S. Santha, M. V. Purohit, R. A. Sidwell, S. Watanabe, G. Herrera, S. Radeztsky, A. C. dos Reis, C. L. Darling, D. J. Summers, K. Gounder, J. M. De Miranda, A.M. Halling, L. Perera, K. Thorne, B. Quinn, Alberto Santoro, R. A. Burnstein, A. Rafatian, G. Hurvits, Kevin Stenson, N. Witchey, K. C. Peng, A. Álvarez Fernández, L. M. Cremaldi, and E. Wolin
Subjects: Physics, Particle decay, Particle physics, Pion, Meson, Branching fraction, High Energy Physics::Phenomenology, Hadron, General Physics and Astronomy, High Energy Physics::Experiment, Energy (signal processing), Pentaquark, Bar (unit)
Abstract: We report results of the first search for the pentaquark P_{{c bar}s} which is predicted to be a doublet of states: P^0_{{c bar}s}=({c bar} s u u d) and P^-_{{c bar}s}=({c bar} s d d u). A search was made for the decay P^0_{{c bar}s} --> phi,pi,p in data from Fermilab experiment E791, in which 500 GeV/c pi^- beam interacted with nuclear targets. We present upper limits at 90% confidence level for the ratio of cross section times branching fraction of this decay to that for the decay D_s --> phi,pi. The upper limits are 0.031 and 0.063 for M(P^0_{{c bar}s}) = 2.75 and 2.86 GeV/c^2, respectively, assuming a P^0_{{c bar}s} lifetime of 0.4 ps.
Published: 1998

29. Branching fractions for D0→K+K− and D0→π+π−, and a search for CP violation in D0 decays

Author: N. Witchey, Simon Kwan, A. Fernandez, A. Nguyen, S. B. Bracker, Don Summers, P.A. Kasper, P. Gagnon, R. Zaliznyak, J. A. Appel, A. K. Tripathi, J. R. T. de Mello Neto, L.P. Perera, J.J. Reidy, A.J. Schwartz, N.J. Copty, S. Radeztsky, C. Zhang, Kevin Stenson, K. C. Peng, D. C. Langs, D. Ashery, A. Napier, R. A. Sidwell, Michael Sokoloff, K. O'Shaughnessy, K. Denisenko, A.M. Halling, S. MayTal-Beck, D. Yi, Alberto Santoro, S. Takach, A.B. d'Oliveira, R. Weiss-Babai, E.M. Aitala, T. Carter, Brian Meadows, C. L. Darling, M. Sheaff, G. Blaylock, Patricia R. Burchat, N. W. Reay, J. Leslie, A.K.S. Santha, K. Thorne, L. M. Cremaldi, E. Wolin, A. Rafatian, R.A. Burnstein, J. C. Anjos, Sudeshna Banerjee, David Sanders, G. Hurvits, J. Solano, S. Amato, K. Gounder, G. F. Fox, J. M. De Miranda, Milind Purohit, I. Bediaga, R. H. Milburn, S. Watanabe, B. Quinn, H. A. Rubin, J. Wiener, B. Lundberg, C. Göbel, C. James, G. Herrera, N. R. Stanton, H.S. Carvalho, A.J. Slaughter, S. Yoshida, and A. C. dos Reis
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, media_common.quotation_subject, CP violation, Fermilab, Charm (quantum number), Branching (polymer chemistry), Asymmetry, High Energy Physics - Experiment, media_common
Abstract: Using the large hadroproduced charm sample collected in experiment E791 at Fermilab, we have measured ratios of branching fractions for the two-body singly-Cabibbo-suppressed charged decays of the D0: (D0 -> KK)/(D0 -> Kpi) = 0.109 +- 0.003 +- 0.003, (D0 -> pipi)/(D0 -> Kpi) = 0.040 +- 0.002 +- 0.003, and (D0 -> KK)/(D0 -> pipi) = 2.75 +- 0.15 +- 0.16. We have looked for differences in the decay rates of D0 and D0bar to the CP eigenstates K+K- and pi+pi-, and have measured the CP asymmetry parameters A_CP(K+K-) = -0.010 +- 0.049 +- 0.012 and A_CP(pi+pi-) = -0.049 +- 0.078 +- 0.030, both consistent with zero., Comment: 10 Postscript pages, including 2 figures. Submitted to Phys. Lett. B
Published: 1998

30. Study of the decay D0→K−K+π−π+

Author: Daniel Ashery, L. M. Cremaldi, E. Wolin, H. A. Rubin, M. V. Purohit, A.K.S. Santha, M. Sheaff, A.B. d'Oliveira, K. O'Shaughnessy, E.M. Aitala, A. J. Slaughter, J. R. T. de Mello Neto, N. K. Copty, I. Bediaga, P.A. Kasper, A. Napier, S. MayTal-Beck, C. James, K. C. Peng, N. W. Reay, J. Leslie, K. Denisenko, D. Yi, C. Zhang, D. J. Summers, K. Gounder, A.M. Halling, L.P. Perera, Kevin Stenson, R. Weiss-Babai, D. C. Langs, J. M. De Miranda, S. Yoshida, B. Quinn, B. T. Meadows, J. A. Appel, J. Solano, R. A. Sidwell, M. D. Sokoloff, S. B. Bracker, P. R. Burchat, G. F. Fox, H.S. Carvalho, N. Witchey, R. H. Milburn, A. Fernandez, R. Zaliznyak, A. C. dos Reis, A.J. Schwartz, B. Lundberg, Simon Kwan, J.J. Reidy, T. Carter, S. Watanabe, P. Gagnon, J. Wiener, A. K. Tripathi, C. Göbel, Sudeshna Banerjee, C. L. Darling, G. Herrera, S. Amato, S. Radeztsky, S. Takach, Alberto Santoro, R. A. Burnstein, A. Rafatian, G. Hurvits, D. A. Sanders, K. Thorne, A. Nguyen, N. R. Stanton, J. C. Anjos, and G. Blaylock
Subjects: Physics, Nuclear and High Energy Physics, Amplitude, Branching fraction, Analytical chemistry, Fermilab, Measure (mathematics)
Abstract: Using data from Fermilab fixed-target experiment E791, we measure the branching ratio for D 0 → K − K + π − π + and its resonant components. We find Γ(D 0 →K − K + π − π + ) Γ(D 0 →K − π + π − π + ) =(3.13±0.37±0.36) %. A coherent amplitude analysis is used to estimate the resonant components. We measure the ratios Γ(D 0 →f) Γ(D 0 →K − π + π − π + ) to be (2.0±0.9±0.8)% for f = φρ 0 , (0.9±0.4±0.5)% for f = φπ + π − , f=K ∗0 (892) K ∗0 (892) , and f= K ∗0 (892)K + π − or K ∗0 (892)K − π + .
Published: 1998

31. Measurement of the Form-Factor Ratios forD+→K¯*0e+νe

Author: N. R. Stanton, N. K. Copty, C. Zhang, P.A. Kasper, D. Mihalcea, Kevin Stenson, A. K. Tripathi, A. C. dos Reis, S. MayTal-Beck, J. Solano, A. J. Slaughter, R. H. Milburn, B. T. Meadows, M. D. Sokoloff, G. P. Gagnon, J. R. T. de Mello Neto, P. R. Burchat, Daniel Ashery, J. Wiener, A. Napier, K. Denisenko, N. W. Reay, J. Leslie, S. Yoshida, K. C. Peng, B. Quinn, D. Yi, D. C. Langs, I. Bediaga, H. A. Rubin, R. Weiss-Babai, D. J. Summers, C. James, K. Gounder, N. Witchey, Simon Kwan, M. V. Purohit, J. M. De Miranda, J.J. Reidy, K. O'Shaughnessy, A.K.S. Santha, S. Banerjee, H.S. Carvalho, Alberto Santoro, J. C. Anjos, A. Álvarez Fernández, B. Lundberg, R. A. Burnstein, L. M. Cremaldi, M. Sheaff, J. A. Appel, E. Wolin, D. A. Sanders, G. Blaylock, A. Rafatian, G. Hurvits, T. Carter, C. L. Darling, R. A. Sidwell, L. Perera, A. J. Schwartz, S. B. Bracker, A.B. d'Oliveira, E.M. Aitala, K. Thorne, S. Takach, S. Radeztsky, A. Nguyen, G. Herrera, S. Amato, A.M. Halling, G. F. Fox, S. Watanabe, and R. Zaliznyak
Subjects: Physics, Particle physics, General Physics and Astronomy, Electron neutrino
Abstract: We present a measurement of the form-factor ratios r_V=V(0)/A_1(0) and r_2=A_2(0)/A_1(0) for the decay D^+ -> \overline K^{*0} e^+ \nu_e. The measurement is based on a signal of approximately 3000 $D^+ -> \overline K^{*0} e^+ \nu_e, \overline K^{*0} -> K^-\pi^+$ decays reconstructed in data from charm hadroproduction experiment E791 at Fermilab. The results are r_V = 1.84 +- 0.11 +- 0.08 and r_2 = 0.71 +- 0.08 +- 0.09.
Published: 1998

32. Search forD0−D0mixing and doubly-Cabibbo-suppressed decays of theD0in hadronic final states

Author: A. Nguyen, L.P. Perera, B. Lundberg, Simon Kwan, P. Gagnon, D. C. Langs, A. Napier, D. Yi, R. Weiss-Babai, Daniel Ashery, C. L. Darling, Milind Purohit, I. Bediaga, C. Zhang, M. Sheaff, A.M. Halling, A.K.S. Santha, A.B. d'Oliveira, E.M. Aitala, Alberto Santoro, H. A. Rubin, N. W. Reay, J. Leslie, K. C. Peng, N. Witchey, N. K. Copty, S. Takach, T. Carter, S. Yoshida, R. Zaliznyak, R. H. Milburn, K. O'Shaughnessy, B. T. Meadows, A. J. Schwartz, K. Thorne, J. A. Appel, A. Álvarez Fernández, M. D. Sokoloff, P. R. Burchat, P.A. Kasper, D. J. Summers, J. C. Anjos, G. Herrera, K. Gounder, J. M. De Miranda, S. B. Bracker, L. M. Cremaldi, E. Wolin, R. A. Sidwell, S. Watanabe, H.S. Carvalho, B. Quinn, R. A. Burnstein, Sudeshna Banerjee, C. James, A. J. Slaughter, A. Rafatian, S. Radeztsky, G. Hurvits, S. Amato, J. R. T. de Mello Neto, Kevin Stenson, A. C. dos Reis, J. Wiener, C. Göbel, J.J. Reidy, S. MayTal-Beck, N. R. Stanton, G. Blaylock, and A. K. Tripathi
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Pion, Hadron, Charge (physics), Sensitivity (control systems), Mixing (physics)
Abstract: We present results of a search for ${D}^{0}\ensuremath{-}{D}^{0}$ mixing and doubly-Cabibbo-suppressed decays of the ${D}^{0}$ in Fermilab experiment E791, a fixed-target charm hadroproduction experiment. We look for evidence of mixing in the decay chain ${D}^{*}\ensuremath{\rightarrow}\ensuremath{\pi}\stackrel{\ensuremath{\rightarrow}}{D}\ensuremath{\pi}(K\ensuremath{\pi}$ or $K\ensuremath{\pi}\ensuremath{\pi}\ensuremath{\pi})$. If the charge of the pion from the ${D}^{*}$ decay is the same as the charge of the kaon from the $D$ decay (a ``wrong-sign'' event), mixing may have occurred. Mixing can be distinguished from other sources of wrong-sign events (such as doubly-Cabibbo-suppressed decays) by analyzing the distribution of decay times. We see no evidence of mixing. Allowing for $\mathrm{CP}$ violation in the interference between DCS and mixing amplitudes our fitted ratio for mixed to unmixed decay rates is ${r}_{\mathrm{mix}}{=(0.39}_{\ensuremath{-}0.32}^{+0.36}\ifmmode\pm\else\textpm\fi{}0.16)%$. This corresponds to a 90% C.L. upper limit of ${r}_{\mathrm{mix}}l0.85%$. The sensitivity of this result is comparable to that of previous measurements, but the assumptions made in fitting the data are notably more general. We present results from many fits to our data under various assumptions. If we assume ${r}_{\mathrm{mix}}=0$, we find a two-sigma wrong-sign enhancement in the $K\ensuremath{\pi}$ mode which we ascribe to doubly Cabibbo-suppressed decays. The ratios of doubly Cabibbo-suppressed decays to Cabibbo-favored decays are ${r}_{\mathrm{dcs}}(K\ensuremath{\pi}{)=(0.68}_{\ensuremath{-}0.33}^{+0.34}\ifmmode\pm\else\textpm\fi{}0.07)%$ and ${r}_{\mathrm{dcs}}(K\ensuremath{\pi}\ensuremath{\pi}\ensuremath{\pi}{)=(0.25}_{\ensuremath{-}0.34}^{+0.36}\ifmmode\pm\else\textpm\fi{}0.03)%$.
Published: 1998

33. Asymmetries between the production of D− and D+ mesons from 500 GeV/c π− nucleon interaction as functions of x and p2

Author: D. C. Langs, A. Nguyen, J. R. T. de Mello Neto, S. Takach, B. T. Meadows, M. D. Sokoloff, P. R. Burchat, K. C. Peng, I. Bediaga, R. Zaliznyak, S. MayTal-Beck, Simon Kwan, G. Blaylock, N. Witchey, K. O'Shaughnessy, A. Fernandez, L. M. Cremaldi, E. Wolin, N. R. Stanton, S. Radeztsky, S. Yoshida, J. Wiener, R. H. Milburn, E.M. Aitala, P. Gagnon, A. Napier, K. Denisenko, Sudeshna Banerjee, S. B. Bracker, C. Göbel, C. Zhang, D. J. Summers, D. Yi, M. V. Purohit, K. Gounder, J. A. Appel, J. M. De Miranda, J.J. Reidy, N. K. Copty, R. Weiss-Babai, A.J. Schwartz, S. Amato, L.P. Perera, A.K.S. Santha, B. Lundberg, N. W. Reay, J. Leslie, C. L. Darling, A.B. d'Oliveira, A.M. Halling, Kevin Stenson, B. Quinn, Daniel Ashery, K. Thorne, S. Watanabe, A. J. Slaughter, H. A. Rubin, D. Mihalcea, C. James, A. C. dos Reis, R. A. Sidwell, Alberto Santoro, A. K. Tripathi, R. A. Burnstein, A. Rafatian, G. Hurvits, M. Sheaff, H.S. Carvalho, G. Herrera, J. C. Anjos, P.A. Kasper, and T. Carter
Subjects: Physics, Nuclear and High Energy Physics, Meson, High Energy Physics::Lattice, media_common.quotation_subject, Nuclear Theory, High Energy Physics::Phenomenology, Asymmetry, Charm quark, Nuclear physics, High Energy Physics::Experiment, Fermilab, Nuclear Experiment, Nucleon, media_common
Abstract: We present measurements of the production of Ds− mesons relative to Ds+ mesons as functions of xF and of pt2 for a sample of 2445 Ds decays to φπ. The Ds mesons were produced in Fermilab experiment E791 with 500 GeV/c π− mesons incident on one platinum and four carbon foil targets. The acceptance-corrected integrated asymmetry in the xF range −0.1 to 0.5 for Ds± mesons is 0.032 ± 0.022 ± 0.022, consistent with no net asymmetry. We compare the results as functions of xF and pt2 to predictions and to the large production asymmetry observed for D± mesons in the same experiment. These comparisons support the hypothesis that production asymmetries come from the fragmentation process and not from the charm quark production itself.
Published: 1997

34. The doubly Cabibbo-suppressed decay D+ → K+ π− π+

Author: S. Yoshida, N. Witchey, A. Fernandez, L. M. Cremaldi, E. Wolin, B. Quinn, L.P. Perera, P.A. Kasper, D. C. Langs, S. B. Bracker, S. Takach, Alberto Santoro, K. O'Shaughnessy, N. K. Copty, R. A. Sidwell, Kevin Stenson, A. Nguyen, S. May Tal-Beck, R. A. Burnstein, A. Napier, D. J. Summers, K. Gounder, K. Denisenko, J. A. Appel, S. Watanabe, J. M. De Miranda, A. Rafatian, J.J. Reidy, K. C. Peng, D. Yi, A.J. Schwartz, M. V. Purohit, R. H. Milburn, R. Weiss-Babai, B. Lundberg, G. Hurvits, I. Bediaga, A.M. Halling, S. Radeztsky, A. C. dos Reis, A.K.S. Santha, K. Thorne, Daniel Ashery, N. R. Stanton, T. Carter, Simon Kwan, A.B. d'Oliveira, C. L. Darling, E.M. Aitala, Sudeshna Banerjee, H. A. Rubin, G. Herrera, P. Gagnon, A. J. Slaughter, B. T. Meadows, N. W. Reay, J. Leslie, M. D. Sokoloff, P. R. Burchat, S. Amato, J. R. T. de Mello Neto, G. Blaylock, R. Zaliznyak, H.S. Carvalho, J. C. Anjos, J. Wiener, C. James, C. Zhang, A. K. Tripathi, and M. Sheaff
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Branching fraction, Analytical chemistry, Dalitz plot, Fermilab
Abstract: We report the observation of the doubly Cabibbo-suppressed decay D + → K + π − π + in data from Fermilab charm hadroproduction experiment E791. With a signal of 59 ± 13 events we measured the ratio of the branching fraction for this mode to that of the Cabibbo-favored decay D + → K − π + π + to be B (D + → K + π − π + ) / B ( D + → K − π + π + ) = (7.7 ± 1.7 ± 0.8) × 10 −3 . A Dalitz plot analysis was performed to search for resonant structures.
Published: 1997

35. Observation of D - π production correlations in 500 GeV π− - N interactions

Author: E.M. Aitala, S. Amato, J.C. Anjos, J.A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S.B. Bracker, P.R. Burchat, R.A. Burnstein, T. Carter, H.S. Carvalho, N.K. Copty, I. Costa, L.M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, P. Gagnon, S. Gerzon, K. Gounder, A.M. Halling, G. Herrera, G. Hurvits, C. James, P.A. Kasper, S. Kwan, D.C. Langs, J. Leslie, B. Lundberg, S. MayTal-Beck, B.T. Meadows, J.R.T. de Mello Neto, R.H. Milburn, J.M. de Miranda, A. Napier, A. Nguyen, A.B. d'Oliveira, K. O'Shaughnessy, K.C. Peng, L.P. Perera, M.V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N.W. Reay, J.J. Reidy, A.C. dos Reis, H.A. Rubin, A.K.S. Santha, A.F.S. Santoro, A.J. Schwartz, M. Sheaff, R.A. Sidwell, A.J. Slaughter, M.D. Sokoloff, N.R. Stanton, K. Stenson, D.J. Summers, S. Takach, K. Thorne, A.K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, FOS: Physical sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), symbols.namesake, Pion, Fragmentation (mass spectrometry), Phase space, Pi, symbols, Feynman diagram, High Energy Physics::Experiment, Fermilab, Nuclear Experiment
Abstract: We study the charge correlations between charm mesons produced in 500 GeV pi- - N interactions and the charged pions produced closest to them in phase space. With 110,000 fully reconstructed D mesons from experiment E791 at Fermilab, the correlations are studied as functions of the Dpi - D mass difference and of Feynman x. We observe significant correlations which appear to originate from a combination of sources including fragmentation dynamics, resonant decays, and charge of the beam., Comment: 12 pages and 2 figures
Published: 1997

36. Measurement of the branching ratio

Author: E.M. Aitala, S. Amato, J.C. Anjos, J.A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S.B. Bracker, P.R. Burchat, R.A. Burnstein, T. Carter, H.S. Carvalho, N.K. Copty, L.M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, P. Gagnon, K. Gounder, A.M. Halling, G. Herrera, G. Hurvits, C. James, P.A. Kasper, S. Kwan, D.C. Langs, J. Leslie, B. Lundberg, S. MayTal-Beck, B. Meadows, J.R.T. de Mello Neto, R.H. Milburn, J.M. de Miranda, A. Napier, A. Nguyen, A.B. d'Oliveira, K. O'Shaughnessy, K.C. Peng, L.P. Perera, M.V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N.W. Reay, J.J. Reidy, A.C. dos Reis, H.A. Rubin, A.K.S. Santha, A.F.S. Santoro, A.J. Schwartz, M. Sheaff, R.A. Sidwell, A.J. Slaughter, M.D. Sokoloff, N.R. Stanton, K. Stenson, D.J. Summers, S. Takach, K. Thorne, A.K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Branching fraction, Charm (quantum number)
Abstract: We report a measurement of the branching ratio B(D+-->rho^0 l nu)/ B(D+-->K*0 l nu) from the Fermilab charm hadroproduction experiment E791. Based on signals of 49+-17 events in the D+--> rho^0 e nu mode and 54+-18 events in the D+--> rho^0 mu nu mode, we measure B(D+-->rho^0 e nu)/B(D+-->K*0 e nu) = 0.045+-0.014+-0.009, and B(D+-->rho^0 mu nu)/B(D+-->K*0 mu nu) = 0.051+-0.015+-0.009. Combining the results from both the electronic and muonic modes, we obtain B(D+-->rho^0 l nu)/B(D+-->K*0 l nu) = 0.047+-0.013. This result is compared to theoretical predictions.
Published: 1997

37. Search forD0D¯0Mixing in Semileptonic Decay Modes

Author: E. M. Aitala, S. Amato, J. C. Anjos, J. A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S. B. Bracker, P. R. Burchat, R. A. Burnstein, T. Carter, H. S. Carvalho, N. K. Copty, I. Costa, L. M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, P. Gagnon, S. Gerzon, C. Gobel, K. Gounder, A. M. Halling, G. Herrera, G. Hurvits, C. James, P. A. Kasper, S. Kwan, D. C. Langs, J. Leslie, B. Lundberg, S. MayTal-Beck, B. Meadows, J. R. T. de Mello Neto, R. H. Milburn, J. M. de Miranda, A. Napier, A. Nguyen, A. B. d'Oliveira, K. O'Shaughnessy, K. C. Peng, L. P. Perera, M. V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N. W. Reay, J. J. Reidy, A. C. dos Reis, H. A. Rubin, A. K. S. Santha, A. F. S. Santoro, A. J. Schwartz, M. Sheaff, R. A. Sidwell, A. J. Slaughter, M. D. Sokoloff, N. R. Stanton, K. Stenson, K. Sugano, D. J. Summers, S. Takach, K. Thorne, A. K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang
Subjects: Physics, Nuclear physics, Semileptonic decay, chemistry, Bar (music), High Energy Physics::Phenomenology, General Physics and Astronomy, chemistry.chemical_element, High Energy Physics::Experiment, Fermilab, Carbon, Mixing (physics)
Abstract: We report the result of a search for D0 - D0_bar mixing in the data from hadroproduction experiment E791 at Fermilab. We use the D* tag and semileptonic decay vertices of D0 to look for wrong-sign decays with mixing time dependence.
Published: 1996

38. Mass splitting and production of Σc0 and Σc++ measured in 500 GeV π− -N interactions

Author: M. Sheaff, Michael Sokoloff, I. Costa, K. O'Shaughnessy, S. Gerzon, Milind Purohit, I. Bediaga, A. Rafatian, H.S. Carvalho, Don Summers, J. G. Smith, L. M. Cremaldi, E. Wolin, R.A. Burnstein, B. Quinn, A. Nguyen, S. Takach, E.M. Aitala, P.A. Kasper, Sudeshna Banerjee, J.J. Reidy, H. A. Rubin, Aleardo Manacero, G. Hurvits, N. R. Stanton, D. C. Langs, C. L. Darling, S. Amato, K. Gounder, J. M. De Miranda, S. B. Bracker, K. C. Peng, J. R. T. de Mello Neto, J. Wiener, J. Lichtenstadt, C. James, Simon Kwan, B. Lundberg, A.J. Slaughter, R. H. Milburn, S. MayTal-Beck, N. Kondakis, N. Witchey, A. K. Tripathi, A.K.S. Santha, T. Carter, K. Sugano, A. Fernandez, Jürgen Engelfried, Patricia R. Burchat, A.J. Schwartz, P. Gagnon, D. Ashery, G. Blaylock, S. Radeztsky, S. Watanabe, L.P. Perera, J. A. Appel, J. C. Anjos, Alberto Santoro, N. W. Reay, J. Leslie, A.M. Halling, Brian Meadows, R. Zaliznyak, R. A. Sidwell, K. Thorne, G. Herrera, A. Napier, K. Denisenko, D. Yi, R. Weiss-Babai, A. C. dos Reis, A. B. d'Oliveira, C. Zhang, and N. K. Copty
Subjects: Physics, Nuclear and High Energy Physics, Mass spectrum, Analytical chemistry, Spectral line
Abstract: From a sample of 2722 ± 78 Λc+ decaying to the pK−π+ final state, we have observed, in the hadroproduction experiment E791 at Fermilab, 143 ± 20 Σc0 and 122 ± 18 Σc++ through their decays to Λc+π±. The mass difference M(Σc0) − M(Λc+) is measured to be (167.38 ± 0.29 ± 0.15) MeV; for M(Σc++) − M(Λc+), we find (167.76 ± 0.29 ± 0.15) MeV. The rate of Λc+ production from decays of the Σc triplet is (22 ± 2 ± 3) % of the total Λc+ production assuming equal rate of production from all three, as measured for Σc0 and Σc++. We do not observe a statistically significant Σc baryon-antibaryon production asymmetry. The xF and pt2 spectra of Λc+ from Σc decays are observed to be similar to those for all Λc+'s produced.
Published: 1996

39. Asymmetries between the production of D+ and D− mesons from 500 GeV/c π−-nucleus interactions as a function of xF and pt2

Author: S. Gerzon, A. Álvarez Fernández, N. Witchey, A. Nguyen, T. Carter, J. G. Smith, B. T. Meadows, B. Quinn, L. M. Cremaldi, E. Wolin, M. D. Sokoloff, N. R. Stanton, P. R. Burchat, D. C. Langs, R. A. Burnstein, A. Napier, A. Rafatian, M. V. Purohit, K. Denisenko, D. Yi, C. Zhang, Daniel Ashery, R. Weiss-Babai, A.K.S. Santha, G. Hurvits, J.J. Reidy, B. Lundberg, K. O'Shaughnessy, A.B. d'Oliveira, E.M. Aitala, K. Sugano, P.A. Kasper, S. Amato, K. C. Peng, Alberto Santoro, H. A. Rubin, S. Banerjee, A. J. Slaughter, S. MayTal-Beck, D. Granite, N. Kondakis, I. Bediaga, L. Perera, J. Wiener, P. Gagnon, J. R. T. de Mello Neto, G. Blaylock, C. Göbel, R. A. Sidwell, K. Thorne, S. Watanabe, J. Astorga, C. L. Darling, C. James, D. J. Summers, K. Gounder, J. M. De Miranda, R. H. Milburn, R. Zaliznyak, H.S. Carvalho, A. C. Reis, A.M. Halling, S. Takach, S. Radeztsky, A. J. Schwartz, G. Herrera, Aleardo Manacero, J. A. Appel, Simon Kwan, N. W. Reay, J. Leslie, S. B. Bracker, M. Aryal, J. C. Anjos, A. K. Tripathi, M. Sheaff, I. Costa, and J. Lichtenstadt
Subjects: Physics, Quark, Nuclear and High Energy Physics, Particle physics, Meson, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, FOS: Physical sciences, Function (mathematics), High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Pi, High Energy Physics::Experiment, Production (computer science), Fermilab, Nuclear Experiment, Nucleon, Beam (structure)
Abstract: We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used.
Published: 1996

40. Publisher’s Note: Model-independent measurement ofS-waveK−π+systems usingD+→Kππdecays from Fermilab E791 [Phys. Rev. D 73, 032004 (2006)]

Author: P. Gagnon, R. Zaliznyak, A.M. Halling, G. Blaylock, M. V. Purohit, S. Banerjee, N. W. Reay, C. L. Darling, J. Leslie, B. T. Meadows, A.B. d'Oliveira, E.M. Aitala, D. C. Langs, M. D. Sokoloff, A.K.S. Santha, P. R. Burchat, N. R. Stanton, B. Lundberg, G. F. Fox, D. J. Summers, Simon Kwan, D. Mihalcea, K. Gounder, K. C. Peng, J. M. De Miranda, S. Devmal, K. O'Shaughnessy, S. Watanabe, M. Sheaff, P.A. Kasper, A. C. dos Reis, N. Witchey, S. M. Yang, A. Napier, K. Denisenko, C. Zhang, S. Yoshida, J. Wiener, C. Göbel, A. Álvarez Fernández, D. Yi, S. B. Bracker, Alberto Santoro, W. M. Dunwoodie, R. H. Milburn, A. J. Slaughter, D. A. Sanders, R. Weiss-Babai, S. Amato, L. M. Cremaldi, R. A. Burnstein, I. Bediaga, E. Wolin, L. Perera, J.J. Reidy, B. Quinn, J. A. Appel, A. Rafatian, K. Thorne, A. Nguyen, S. Takach, A. Massafferri, G. Hurvits, R. A. Sidwell, S. Radeztsky, S. MayTal-Beck, T. Carter, A. K. Tripathi, C. James, J. Magnin, Kevin Stenson, J. C. Anjos, J. R. T. de Mello Neto, A. J. Schwartz, G. Herrera, H.S. Carvalho, N. K. Copty, J. Solano, Daniel Ashery, H. A. Rubin, and R. J. Stefanski
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Particle decay, S-wave, Pi, Fermilab
Published: 2006

41. Model-independent measurement ofS-waveK−π+systems usingD+→Kππdecays from Fermilab E791

Author: E. M. Aitala, S. Amato, J. C. Anjos, J. A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S. B. Bracker, P. R. Burchat, R. A. Burnstein, T. Carter, H. S. Carvalho, N. K. Copty, L. M. Cremaldi, C. Darling, K. Denisenko, S. Devmal, A. Fernandez, G. F. Fox, P. Gagnon, C. Gobel, K. Gounder, A. M. Halling, G. Herrera, G. Hurvits, C. James, P. A. Kasper, S. Kwan, D. C. Langs, J. Leslie, B. Lundberg, J. Magnin, A. Massafferri, S. MayTal-Beck, B. Meadows, J. R. T. de Mello Neto, D. Mihalcea, R. H. Milburn, J. M. de Miranda, A. Napier, A. Nguyen, A. B. d’Oliveira, K. O’Shaughnessy, K. C. Peng, L. P. Perera, M. V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N. W. Reay, J. J. Reidy, A. C. dos Reis, H. A. Rubin, D. A. Sanders, A. K. S. Santha, A. F. S. Santoro, A. J. Schwartz, M. Sheaff, R. A. Sidwell, A. J. Slaughter, M. D. Sokoloff, J. Solano, N. R. Stanton, R. J. Stefanski, K. Stenson, D. J. Summers, S. Takach, K. Thorne, A. K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, S. M. Yang, D. Yi, S. Yoshida, R. Zaliznyak, C. Zhang, and W. M. Dunwoodie
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Particle decay, Pion, Meson, Partial wave analysis, Hadron, Dalitz plot, Production (computer science), Invariant mass
Abstract: A model-independent partial-wave analysis of the S-wave component of the K{pi} system from decays of D{sup +} mesons to the three-body K{sup -}{pi}{sup +}{pi}{sup +} final state is described. Data come from the Fermilab E791 experiment. Amplitude measurements are made independently for ranges of K{sup -}{pi}{sup +} invariant mass, and results are obtained below 825 MeV/c{sup 2}, where previous measurements exist only in two mass bins. This method of parametrizing a three-body decay amplitude represents a new approach to analyzing such decays. Though no model is required for the S-wave, a parametrization of the relatively well-known reference P- and D-waves, optimized to describe the data used, is required. In this paper, a Breit-Wigner model is adopted to describe the resonances in these waves. The observed phase variation for the S-, P-, and D-waves do not match existing measurements of I=(1/2) K{sup -}{pi}{sup +} scattering in the invariant mass range in which scattering is predominantly elastic. If the data are mostly I=(1/2), this observation indicates that the Watson theorem, which requires these phases to have the same dependence on invariant mass, may not apply to these decays without allowing for some interaction with the other pion. The production rate of K{supmore » -}{pi}{sup +} from these decays, if assumed to be predominantly I=(1/2), is also found to have a significant dependence on invariant mass in the region above 1.25 GeV/c{sup 2}. These measurements can provide a relatively model-free basis for future attempts to determine which strange scalar amplitudes contribute to the decays.« less
Published: 2006

42. Dalitz Plot Analysis of the DecayD+→K−π+π+and Indication of a Low-Mass ScalarKπResonance

Author: dos Reis Ac, S. M. Yang, J. Magnin, S. Yoshida, K. C. Peng, A. K. Tripathi, S. MayTal-Beck, P.A. Kasper, A.M. Halling, D. A. Sanders, J. C. Anjos, Simon Kwan, K. O'Shaughnessy, L. Perera, S. Takach, H.S. Carvalho, C. James, Alberto Santoro, K. Thorne, A. Álvarez Fernández, N. Witchey, J. Wiener, B. Lundberg, A. J. Slaughter, S. Banerjee, C. Göbel, D. C. Langs, L. M. Cremaldi, E. Wolin, C. Zhang, J.J. Reidy, A. J. Schwartz, D. Mihalcea, S. Radeztsky, R. A. Sidwell, B. Quinn, A. Nguyen, N. W. Reay, J. Leslie, I. Bediaga, A. Napier, G. Herrera, R. Zaliznyak, K. Denisenko, R. H. Milburn, G. Blaylock, M. V. Purohit, de Mello Neto, M. Sheaff, P. Gagnon, J. A. Appel, S. Amato, D. J. Summers, K. Gounder, A.K.S. Santha, N. R. Stanton, D. Yi, T. Carter, R. Weiss-Babai, Solano Salinas Cj, G. F. Fox, C. L. Darling, A. Massafferri, de Miranda Jm, B. T. Meadows, Kevin Stenson, P. R. Burchat, S. Watanabe, R. A. Burnstein, A. Rafatian, A.B. d'Oliveira, E.M. Aitala, G. Hurvits, S. B. Bracker, R. J. Stefanski, N. K. Copty, Sokoloff, Daniel Ashery, H. A. Rubin, and S. Devmal
Subjects: Physics, Particle decay, Particle physics, Pion, Meson, Hadron, General Physics and Astronomy, Resonance, Dalitz plot, Elementary particle, Boson
Abstract: We study the Dalitz plot of the decay ${D}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known $K\ensuremath{\pi}$ resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the ${K}_{0}^{*}(1430)$ to float, we obtain values consistent with those from PDG but the ${\ensuremath{\chi}}^{2}$ per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass $797\ifmmode\pm\else\textpm\fi{}19\ifmmode\pm\else\textpm\fi{}43\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{\mathrm{2}}$ and width $410\ifmmode\pm\else\textpm\fi{}43\ifmmode\pm\else\textpm\fi{}87\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{2}$. The mass and width of the ${K}_{0}^{*}(1430)$ become $1459\ifmmode\pm\else\textpm\fi{}7\ifmmode\pm\else\textpm\fi{}5\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{\mathrm{2}}$ and $175\ifmmode\pm\else\textpm\fi{}12\ifmmode\pm\else\textpm\fi{}12\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{\mathrm{2}}$, respectively. Our results provide new information on the scalar sector in hadron spectroscopy.
Published: 2002

43. Differential cross sections, charge production asymmetry, and spin-density matrix elements for D*(2010) produced in 500 GeV/c pi^- nucleon interactions

Author: J.J. Reidy, A. J. Slaughter, R. A. Burnstein, Kevin Stenson, A. Rafatian, J. A. Appel, R. Zaliznyak, D. J. Summers, K. Gounder, J. M. De Miranda, G. Hurvits, C. James, P.A. Kasper, N. R. Stanton, A. Massafferri, A. Nguyen, C. Zhang, C. J. Solano Salinas, M. V. Purohit, S. MayTal-Beck, K. O'Shaughnessy, B. T. Meadows, J. R. T. de Mello Neto, M. D. Sokoloff, P. R. Burchat, A.M. Halling, S. M. Yang, N. Witchey, A.K.S. Santha, H.S. Carvalho, N. W. Reay, J. Leslie, A.K. Tripathi, S. Yoshida, A. Fernandez, J. Magnin, Alberto Santoro, S. Takach, D. C. Langs, J. C. Anjos, T. Carter, S. B. Bracker, Simon Kwan, G. F. Fox, G. Blaylock, K. C. Peng, R. H. Milburn, P. Gagnon, R. A. Sidwell, S. Radeztsky, M. Sheaff, B. Quinn, S. Watanabe, B. Lundberg, Sudeshna Banerjee, C. L. Darling, A. J. Schwartz, I. Bediaga, D. Mihalcea, S. Amato, A. C. dos Reis, L. M. Cremaldi, E. Wolin, A.B. d'Oliveira, E.M. Aitala, D. A. Sanders, G. Herrera, K. Thorne, S. Devmal, L.P. Perera, A. Napier, K. Denisenko, D. Yi, R. Weiss-Babai, J. Wiener, C. Göbel, N. K. Copty, R. J. Stefanski, Daniel Ashery, and H. A. Rubin
Subjects: Physics, Scattering cross-section, Nuclear and High Energy Physics, media_common.quotation_subject, FOS: Physical sciences, Polarization (waves), Asymmetry, High Energy Physics - Experiment, Nuclear physics, symbols.namesake, High Energy Physics - Experiment (hep-ex), Transverse momentum, symbols, Feynman diagram, High Energy Physics::Experiment, Fermilab, Atomic physics, Spin density, Nucleon, Nuclear Experiment, media_common
Abstract: We report differential cross sections for the production of D*(2010) produced in 500 GeV/c pi^- nucleon interactions from experiment E791 at Fermilab, as functions of Feynman-x (x_F) and transverse momentum squared (p_T^2). We also report the D* +/- charge asymmetry and spin-density matrix elements as functions of these variables. Investigation of the spin-density matrix elements shows no evidence of polarization. The average values of the spin alignment are \eta= 0.01 +- 0.02 and -0.01 +- 0.02 for leading and non-leading particles, respectively., Comment: LaTeX2e (elsart.cls). 13 pages, 6 figures (eps files). Submitted to Physics Letters B
Published: 2002

44. Dalitz plot analysis of the decay D(+)--K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance

Author: E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Göbel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, A, Massafferri, S, MayTal-Beck, B, Meadows, J R T, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K S, Santha, A F S, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, C J, Solano Salinas, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang
Abstract: We study the Dalitz plot of the decay D(+)--K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.
Published: 2002

45. Design of the Slow POsitron faciliTy (SPOT) in Israel

Author: S. May-Tal Beck, I. Sabo-Napadensky, Guy Ron, Or Hen, A Kelleher, J Dumas, R. Weiss-Babai, Dan Cohen, E. Piasetzky, N. Pilip, and Eliahu Cohen
Subjects: History, Engineering, business.industry, Positron beam, Nuclear engineering, chemistry.chemical_element, Computer Science Applications, Education, Neon, Positron, chemistry, Physics::Accelerator Physics, business, Engineering design process, Beam (structure), Simulation
Abstract: A slow positron beam is being built in the Hebrew University, the Slow POsitron faciliTy (SPOT). In Israel, the beam will introduce a new tool for both fundamental and applied research. Here we present the design process of the beam, where the leading goals are safety and high efficiency, with a flexible choice of the positron source. The challenges in the design of a moderator unit, based on frozen Neon, the pre-accelerator section and the full beam-line were addressed by simulation programs using various packages: COMSOL, SIMION and GEANT4. First measurements in SPOT are expected within a year.
Published: 2014

46. Study of the decayD0→K−K−K+π+

Author: N. Witchey, D.C. Langs, J. A. Appel, S. Devmal, C. Zhang, A. Álvarez Fernández, D. A. Sanders, S. M. Yang, Michael Sokoloff, S. Yoshida, S. Takach, L. M. Cremaldi, E. Wolin, K. O'Shaughnessy, L.P. Perera, R. Zaliznyak, Kevin Stenson, J. C. Anjos, D. Mihalcea, A. M. Halling, Daniel Ashery, A. Napier, P.A. Kasper, G. F. Fox, A. C. dos Reis, S. Radeztsky, K. Denisenko, D. Yi, R. Weiss-Babai, J. Lichtenstadt, K. Thorne, S. Banerjee, S. B. Bracker, D. J. Summers, M. V. Purohit, A. Nguyen, S. Watanabe, K. Gounder, J. M. De Miranda, K. C. Peng, A.B. d'Oliveira, E.M. Aitala, R. H. Milburn, A.K.S. Santha, N. K. Copty, B. Quinn, T. Carter, C. James, J. Solano, P. Gagnon, A. J. Slaughter, J. R. T. de Mello Neto, S. Amato, J. Wiener, N. W. Reay, J. Leslie, M. Sheaff, R. J. Stefanski, C. Göbel, R. A. Sidwell, C. L. Darling, H. A. Rubin, A. J. Schwartz, S. Kwan, S. MayTal-Beck, S. Gerzon, G. Herrera, A.K. Tripathi, B. T. Meadows, P. R. Burchat, J.J. Reidy, R. A. Burnstein, I. Bediaga, A. Rafatian, H.S. Carvalho, B. Lundberg, G. Hurvits, Alberto Santoro, G. Blaylock, and N. R. Stanton
Subjects: Physics, Nuclear and High Energy Physics, chemistry, Vacuum state, Analytical chemistry, Pi, chemistry.chemical_element, Platinum, Carbon
Published: 2001

47. Search for rare and forbidden Charm Meson decays D0 --Vl+l- and hhll

Author: E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Gobel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, S, MayTal-Beck, B, Meadows, J R, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K, Santha, A F, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, J, Solano, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang
Abstract: We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).
Published: 2000

48. Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared

Author: A. Napier, K. Denisenko, D. Yi, R. Weiss-Babai, R. A. Burnstein, J. Wiener, A. Rafatian, L.P. Perera, A. J. Schwartz, B. Lundberg, A.M. Halling, C. Göbel, N. R. Stanton, G. Hurvits, N. W. Reay, A. J. Slaughter, J. Leslie, S. Radeztsky, A. Nguyen, G. Herrera, Alberto Santoro, S. Gerzon, J. A. Appel, R. A. Sidwell, B. T. Meadows, A. Álvarez Fernández, Kevin Stenson, L. M. Cremaldi, E. Wolin, D. J. Summers, K. Gounder, J. M. De Miranda, Daniel Ashery, H. A. Rubin, Simon Kwan, N. Witchey, D.C. Langs, M. V. Purohit, P. Gagnon, D. A. Sanders, R. H. Milburn, Sudeshna Banerjee, P.A. Kasper, A.K.S. Santha, N. K. Copty, K. Thorne, K. C. Peng, S. Takach, S. Amato, J. C. Anjos, I. Bediaga, M. Sheaff, G. F. Fox, G. Blaylock, R. Zaliznyak, A.B. d'Oliveira, E.M. Aitala, C. L. Darling, S. Watanabe, J. R. T. de Mello Neto, D. Mihalcea, H.S. Carvalho, A. C. dos Reis, S. Deval, Michael Sokoloff, J. Lichtenstadt, K. O'Shaughnessy, S. M. Yang, S. Yoshida, B. Quinn, S. MayTal-Beck, A.K. Tripathi, S. B. Bracker, J. Solano, J.J. Reidy, Patricia R. Burchat, T. Carter, R. J. Stefanski, C. Zhang, and C. James
Subjects: Quark, Physics, Particle physics, Valence (chemistry), General Physics and Astronomy, FOS: Physical sciences, Square (algebra), High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, Light cone, Transverse momentum, High Energy Physics::Experiment, Fermilab, Wave function, Nuclear Experiment
Abstract: We present the first direct measurements of the pion valence quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c $��^-$ into di-jets from a platinum target at Fermilab experiment E791. The results show that the $|q\bar {q}>$ light-cone asymptotic wave function, which was developed using perturbative QCD methods, describes the data well for $Q^2 \sim 10 ~{\rm (GeV/c)^2}$ or more. We also measured the transverse momentum distribution of the diffractive di-jets., 13 pages, 4 figures
Published: 2000

49. Experimental evidence for a light and broad scalar resonance in D(+) --pi(-)pi(+)pi(+) decay

Author: E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Gobel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, A, Massafferri, S, MayTal-Beck, B, Meadows, J R, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K, Santha, A F, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, J, Solano, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang
Abstract: From a sample of 1172 +/- 61 D(+)--pi(-)pi(+)pi(+) decays, we find gamma(D(+)--pi(-)pi(+)pi(+))/gamma(D(+)--K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.
Published: 2000

50. Study of the D(+)(s)--pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths

Author: E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Gobel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, A, Massafferri, S, MayTal-Beck, B, Meadows, J R, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K, Santha, A F, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, J, Solano, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang
Abstract: From a sample of 848+/-44 D(+)(s)--pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)--pi(-)pi(+)pi(+))/gamma(D(+)(s)--straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).
Published: 2000

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