ArcAdiA

Study of the ATLAS MDT spectrometer using high energy CERN combined test beam data

2008-12-31T23:00:00Z

Study of the ATLAS MDT spectrometer using high energy CERN combined test beam data Adorisio, C.; Aielli, G.; Alexopoulos, Th.; Alviggi, M.; Amelung, C.; Anastopoulos, Ch.; Avolio, G.; Avramidou, R.; Bachas, K.; Bagnaia, P.; Ball, R.; Lacava, F.; Lancon, E.; Lanza, A.; Laporte, J. -F.; Lellouch, D.; Levin, D. S.; Levinson, L.; Liberti, B.; Lifshitz, R.; Linde, F.; Barisonzi, M.; Luci, C.; Lupu, N.; Maccarrone, G.; Maeno, T.; Mair, K.; Maltezos, S.; Manz, A.; Marchesotti, M.; Meoni, E.; Mikenberg, G.; Baroncelli, Antonio; Mohr, W.; Mohrdieck-Moeck, S.; Nagano, K.; Nicolaidou, R.; Nikolaev, K.; Nikolopoulos, K.; Nisati, A.; Nomoto, H.; Oliver, J.; Orestano, Domizia; Barone, M.; Osborne, L. S.; Ouraou, A.; Palestini, S.; Pasqualucci, E.; Passeri, Antonio; Pastore, F.; Patricelli, S.; Perrino, R.; Petridou, Ch.; Petrucci, Fabrizio; Bauer, F.; Podkladkin, S.; Policicchio, A.; Pomarede, D.; Ponsot, P.; Pontecorvo, L.; Primavera, M.; Rebuzzi, D.; Richter, R.; Rimoldi, A.; Rosati, S.; Bellomo, M.; Rothberg, J.; Sakamoto, H.; Salvatore, D.; Sampsonidis, D.; Santonico, R.; Sasaki, O.; Schricker, A.; Schuh, S.; Schune, P.; Shoa, M.; Benhammou, Y.; Skvorodnev, N.; Sliwa, K.; Camillocci, E. Solfaroli; Spagnolo, S.; Spogli, L.; Strauss, E.; Sugaya, Y.; Tanaka, S.; Tarem, S.; Taylor, F. E.; Bensinger, J.; Todorova, S.; Trigger, I.; Tsiafis, I.; Tsipolitis, G.; Valderanis, Ch.; Valente, P.; Vandelli, W.; van der Graaf, H.; Vari, R.; Veneziano, S.; Beretta, M.; Ventura, A.; Ventura, S.; Vermeulen, J.; Vlachos, S.; Vreeswijk, M.; Yasu, Y.; Wellenstein, H.; Werneke, P.; Wijnen, T.; Wolter, M.; Bianchi, Riccardo Maria; Wotschack, J.; Woudstra, M.; Zema, F.; Zhao, Z.; Zhemchugov, A.; Zhou, B.; Zimmerman, S.; Bianco, M.; Bini, C.; Bobbink, G.; Borisov, A.; Boterenbrood, H.; Boyko, I.; Branchini, Paolo; Brambilla, E.; Brandenburg, G.; Bratzler, U.; Bressler, S.; Brouwer, G.; Cambiaghi, M.; Canale, V.; Caprio, M.; Cardarelli, R.; Cerutti, F.; Chapman, J. W.; Chelkov, G.; Chevalier, L.; Chiodini, G.; Cirilli, M.; Coco, R.; Curatolo, M.; Dai, T.; De Asmundis, R.; Dedovich, D.; Della Pietra, M.; Della Volpe, D.; DeZorzi, G.; Di Ciaccio, A.; DiDomenico, A.; Di Luise, Silvestro; Di Simone, A.; Dris, M.; Dushkin, A.; Ernwein, J.; Esposito, B.; Etzion, E.; Fakhrutdinov, R.; Falciano, S.; Fassouliotis, D.; Ferrari, R.; Formica, A.; Fukunaga, C.; Gaudio, G.; Gazis, Ev.; Giraud, P. -F.; Gorini, E.; Grancagnolo, F.; Gregory, J. A.; Groenstege, H.; da Costa, J. Guimaraes; Guyot, C.; Harel, A.; Hart, R.; Hashemi, K.; Hassani, S.; Herten, G.; Horvat, S.; Hurst, P.; Ichimiya, R.; Lengo, P.; Ikeno, M.; Ioannou, P.; Iodice, Mauro; Ishino, M.; Iwasaki, H.; Kataoka, Y.; Khodinov, A.; Konig, A.; Kortner, O.; Kotov, S.; Kourkoumelis, C.; Kozhin, A.; Krepouri, A.; Kroha, H.; Krumshteyn, Z.; Kurashige, H.; Landgraf, U. 2009-01 Nuclear instruments & methods in physics research section A, Accelerators spectrometers, detectors and associated equipment 598 400-415 In 2004, a combined system test was performed in the H8 beam line atthe CERN SPS with a setup reproducing the geometry of sectors of theATLAS Muon Spectrometer, formed by three stations of Monitored DriftTubes (MDT). The full ATLAS analysis chain Was used to obtain theresults presented in this paper. The basic design performances of theWon Spectrometer were verified. The stability of MDT calibrationconstants, the alignment system using optical devices and high energytracks, as well as the intrinsic sagitta resolution of the MuonSpectrometer were studied and found to agree with expectations. Thereconstruction of muon tracks using the combined information from boththe Inner Detector and the Muon Spectrometer are also presented. (C)2008 Elsevier B.V. All rights reserved.

Construction and tests of a fine granularity lead-scintillating fibers calorimeter

2008-12-31T23:00:00Z

Construction and tests of a fine granularity lead-scintillating fibers calorimeter Branchini, Paolo; Ceradini, Filippo; Corradi, Giovanni; Di Micco, Biagio; Passeri, Antonio 2009-01 Journal of Physics: Conference Series 160 1-8 We report the construction and the tests of a small prototype of the lead-scintillating fiber calorimeter of the KLOE experiment, instrumented with multianode photomultipliers to obtain a 16 times finer readout granularity. The prototype is 15 cm wide, 15 radiation lengths deep and is made of 200 layers of fibers 50 cm long. On one side it is read out with an array of 3×5 multianode photomultipliers Hamamatsu type R8900-M16, each segmented with 4×4 anodes, the read out granularity being 240 pixels of 11×11 mm2 corresponding to about 64 scintillating fibers each. These are interfaced to the 6×6 mm2 pixeled photocathode with truncated pyramid light guides made of Bicron BC-800 plastic to partially transmit the UV light. Each photomultiplier provides also an OR of the 16 last dynodes that is used for trigger. The response of the individual anodes, their relative gain and cross-talk has been measured with the light (440 nm) of a laser illuminating only few fibers on the side opposite to the readout. We finally present the first results of the calorimeter response to cosmic rays in autotrigger mode.

Calibration and performances of the KLOE calorimeter

2008-12-31T23:00:00Z

Calibration and performances of the KLOE calorimeter Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Bacci, Cesare; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocchetta, Simona Serena; Bossi, F.; Branchini, Paolo; Campana, P.; Capon, G.; Capussela, T.; Ceradini, Filippo; Chi, S.; Chiefari, G.; Ciambrone, P.; Crucianelli, F.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, Biagio; Doria, A.; Dreucci, M.; Felici, G.; Ferrari, A.; Ferrer, M. L.; Fiore, S.; Forti, C.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Gorini, E.; Graziani, E.; Kluge, W.; Kulikov, V.; Lacava, F.; Lanfranchi, G.; Lee-Franzini, J.; Leone, D.; Martini, M.; Massarotti, P.; Mei, W.; Meola, S.; Miscetti, S.; Moulson, M.; Mueller, S.; Murtas, F.; Napolitano, M.; Nguyen, Federico; Palutan, M.; Pasqualucci, E.; Passeri, Antonio; Patera, V.; Perfetto, F.; Primavera, M.; Santangelo, P.; Saracino, G.; Sciascia, B.; Sciubba, A.; Sibidanov, A.; Spadaro, T.; Testa, M.; Tortora, Ludovico; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G. 2009-01-01 Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment 598 239-243 The KLOE experiment uses a fine sampling lead-scintillating fibrecalorimeter to measure energy, time and position of neutral and charged particles. The overall detector consists of 88 modules organised in a barrel and two end-caps, for a total granularity of 2440 cells, read-out by photo-multipliers at both fibre ends. The chosen design of a high sampling fraction with the usage of thin lead layers and fast scintillating fibres allows to reach good efficiency for photonenergies down to few MeV, good energy resolution and excellent time resolution. The design, calibration and performances of the calorimeter on efficiency, time/position/energy resolution and particle identification is reviewed. The overall calorimeter impact on kaon tagging and on physics results is also presented.

Measurement of the branching ratio and search for a CP violating asymmetry in the η→π+π−e+e− (γ ) decay at KLOE

2009-05-17T22:00:00Z

Measurement of the branching ratio and search for a CP violating asymmetry in the η→π+π−e+e− (γ ) decay at KLOE Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocchetta, Simona; Bossi, F.; Branchini, Paolo; Capon, G.; Capussela, T.; Ceradini, Filippo; Ciambrone, P.; Crucianelli, F.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, Biagio; Dreucci, M.; Felici, G.; Fiore, S.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Graziani, Enrico; Lanfranchi, G.; Lee-Franzini, J.; Leone, D.; Martini, M.; Massarotti, P.; Meola, S.; Miscetti, S.; Moulson, M.; Mueller, S.; Murtas, F.; Napolitano, M.; Nguyen, Federico; Palutan, M.; Pasqualucci, E.; Passeri, Antonio; Patera, V.; Perfetto, F.; Santangelo, P.; Sciascia, B.; Spadaro, T.; Testa, M.; Tortora, Ludovico; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G. 2009-05-18 Physics Letters B 675 283-288 We have studied the η→π+π−e+e− (γ ) decay using about 1.7 fb−1 collected by the KLOE experiment at the DA NE φ-factory. This corresponds to about 72 millions η mesons produced in φ radiative decays. We have measured the branching ratio, inclusive of radiative effects, with 4% accuracy: BR(η→ π+π−e+e− (γ )) = (26.8 ± 0.9Stat. ± 0.7Syst.) × 10−5. We have obtained the first measurement of the CPodd ππ–ee decay planes angular asymmetry, Aφ = (−0.6±2.5Stat. ±1.8Syst.)×10−2.

Temperature effect on RPC performance in the ARGO-YBJ experiment

2009-08-31T22:00:00Z

Temperature effect on RPC performance in the ARGO-YBJ experiment Aielli, G.; Bacci, Cesare; Bartoli, B.; Bernardini, P.; Bi, X. J.; Bleve, C.; Branchini, Paolo; Budano, Antonio; Bussino, Severino; Calabrese Melcarne, A. K.; Camarri, P.; Cao, Z.; Cappa, A.; Cardarelli, R.; Catalanotti, S.; Cattaneo, C.; Celio, Paola; Chen, S. Z.; Chen, Y.; Cheng, N.; Creti, P.; Cui, S. W.; Dai, B. Z.; D'Ali Staiti, G.; Danzengluobu; Dattoli, M.; De Mitri, I.; D'Ettorre Piazzoli, B.; De Vincenzi, Mario; Di Girolamo, T.; Ding, X. H.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Galeazzi, Fulvio; Galeotti, P.; Gargana, Riccardo; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Huang, Q.; Iacovacci, M.; Iuppa, R.; James, Irina; Jia, H. Y.; Labaciren; Li, H. J.; Li, J. Y.; Li, X. X.; Liberti, B.; Liguori, G.; Liu, C.; Liu, C. Q.; Liu, M. Y.; Liu, J.; Lu, H.; Ma, X. H.; Mancarella, G.; Mari, Stefano Maria; Marsella, G.; Martello, D.; Mastroianni, S.; Meng, X. R.; Montini, Paolo; Ning, C. C.; Pagliaro, A.; Panareo, M.; Perrone, L.; Pistilli, Pio; Qu, X. B.; Rossi, E.; Ruggieri, Federico; Saggese, L.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Stanescu, Cristian; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, B.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xu, B.; Xue, L.; Yan, Y. X.; Yang, Q. Y.; Yang, X. C.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, JiLong; Zhang, JianLi; Zhang, L.; Zhang, P.; Zhang, X. Y.; Zhang, Y.; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Zizzi, G. 2009-09 Nuclear Instruments & Methods in Physics Research. Section A 608 246-250 The ARGO-YBJ experiment has been taking data for nearly 2 years. In order to monitor continuously the performance of the Resistive Plate Chamber detectors and to study the daily temperature effects on the detector performance, a cosmic ray muon telescope was setup near the carpet detector array in the ARGO-YBJ laboratory. Based on the measurements performed using this telescope, it is found that, at the actual operating voltage of 7.2kV, the temperature effect on the RPC time resolution is about 0.04ns/degrees C and on the particle detection efficiency is about 0.03%/degrees C. Based on these figures we conclude that the environmental effects do not affect substantially the angular resolution of the ARGO-YBJ detector.

Proton-air cross section measurement with the ARGO-YBJ cosmic ray experiment

2009-11-15T23:00:00Z

Proton-air cross section measurement with the ARGO-YBJ cosmic ray experiment Aielli, G.; Bacci, Cesare; Bartoli, B.; Bernardini, P.; Bi, X. J.; Bleve, C.; Branchini, Paolo; Budano, A.; Bussino, Severino; Calabrese Melcarne, A. K.; Camarri, P.; Cao, Z.; Cappa, A.; Cardarelli, R.; Catalanotti, S.; Cattaneo, C.; Celio, Paola; Chen, S. Z.; Chen, Y.; Cheng, N.; Creti, P.; Cui, S. W.; Dai, B. Z.; D'Ali Staiti, G.; Danzengluobu; Dattoli, M.; De Mitri, I.; D'Ettorre Piazzoli, B.; De Vincenzi, Mario; Di Girolamo, T.; Ding, X. H.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Galeazzi, Fulvio; Galeotti, P.; Gargana, Riccardo; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Huang, Q.; Iacovacci, M.; Iuppa, R.; James, Irina; Jia, H. Y.; Labaciren; Li, H. J.; Li, J. Y.; Li, X. X.; Liberti, B.; Liguori, G.; Liu, C.; Liu, C. Q.; Liu, M. Y.; Liu, J.; Lu, H.; Ma, X. H.; Mancarella, G.; Mari, Stefano Maria; Marsella, G.; Martello, D.; Mastroianni, Stefano; Meng, X. R.; Montini, Paolo; Ning, C. C.; Pagliaro, A.; Panareo, M.; Perrone, L.; Pistilli, Pio; Qu, X. B.; Rossi, E.; Ruggieri, Federico; Saggese, L.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Stanescu, Cristian; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, B.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xu, B.; Xue, L.; Yan, Y. X.; Yang, Q. Y.; Yang, X. C.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, JiLong; Zhang, JianLi; Zhang, L.; Zhang, P.; Zhang, X. Y.; Zhang, Y.; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Zizzi, G. 2009-11-16 Physical Review D 80 092004 The proton-air cross section in the energy range 1-100 TeV has been measured by the ARGO-YBJ cosmic ray experiment. The analysis is based on the primary cosmic ray flux attenuation for different atmospheric depths (i.e. zenith angles) and exploits the detector capabilities of selecting the shower development stage by means of hit multiplicity, density and lateral profile measurements at ground. The effects of shower fluctuations, the contribution of heavier primaries and the uncertainties of the hadronic interaction models, have been taken into account. The results have been used to estimate the total proton-proton cross section at center-of-mass energies between 70 and 500 GeV, where no accelerator data are currently available.

Study of the ATLAS MDT spectrometer using high energy CERN combined test beam data

2009-01-10T23:00:00Z

Study of the ATLAS MDT spectrometer using high energy CERN combined test beam data Adorisio, C.; Aielli, G.; Alexopoulos, Th.; Alviggi, M.; Amelung, C.; Anastopoulos, Ch.; Avolio, G.; Avramidou, R.; Bachas, K.; Bagnaia, P.; Ball, R.; Barisonzi, M.; Baroncelli, Antonio; Barone, M.; Bauer, F.; Bellomo, M.; Benhammou, Y.; Bensinger, J.; Beretta, M.; Bianchi, Riccardo Maria; Bianco, M.; Bini, C.; Bobbink, G.; Borisov, A.; Boterenbrood, H.; Boyko, I.; Branchini, Paolo; Brambilla, E.; Brandenburg, G.; Bratzler, U.; Bressler, S.; Brouwer, G.; Cambiaghi, M.; Canale, V.; Caprio, M.; Cardarelli, R.; Cerutti, F.; Chapman, J. W.; Chelkov, G.; Chevalier, L.; Chiodini, G.; Cirilli, M.; Coco, R.; Curatolo, M.; Dai, T.; De Asmundis, R.; Dedovich, D.; Della Pietra, M.; Della Volpe, D.; DeZorzi, G.; Di Ciaccio, A.; DiDomenico, A.; Di Luise, Silvestro; Di Simone, A.; Dris, M.; Dushkin, A.; Ernwein, J.; Esposito, B.; Etzion, E.; Fakhrutdinov, R.; Falciano, S.; Fassouliotis, D.; Ferrari, R.; Formica, A.; Fukunaga, C.; Gaudio, G.; Gazis, Ev.; Giraud, P. -F.; Gorini, E.; Grancagnolo, F.; Gregory, J. A.; Groenstege, H.; Guimaraes da Costa, J.; Guyot, C.; Harel, A.; Hart, R.; Hashemi, K.; Hassani, S.; Herten, G.; Horvat, S.; Hurst, P.; Ichimiya, R.; Lengo, P.; Ikeno, M.; Ioannou, P.; Iodice, Mauro; Ishino, M.; Iwasaki, H.; Kataoka, Y.; Khodinov, A.; Konig, A.; Kortner, O.; Kotov, S.; Kourkoumelis, C.; Kozhin, A.; Krepouri, A.; Kroha, H.; Krumshteyn, Z.; Kurashige, H.; Landgraf, U.; Lacava, F.; Lancon, E.; Lanza, A.; Laporte, J. -F.; Lellouch, D.; Levin, D. S.; Levinson, L.; Liberti, B.; Lifshitz, R.; Linde, F.; Luci, C.; Lupu, N.; Maccarrone, G.; Maeno, T.; Mair, K.; Maltezos, S.; Manz, A.; Marchesotti, M.; Meoni, E.; Mikenberg, G.; Mohr, W.; Mohrdieck-Moeck, S.; Nagano, K.; Nicolaidou, R.; Nikolaev, K.; Nikolopoulos, K.; Nisati, A.; Nomoto, H.; Oliver, J.; Orestano, Domizia; Osborne, L. S.; Ouraou, A.; Palestini, S.; Pasqualucci, E.; Passeri, Antonio; Pastore, F.; Patricelli, S.; Perrino, R.; Petridou, Ch.; Petrucci, Fabrizio; Podkladkin, S.; Policicchio, A.; Pomarede, D.; Ponsot, P.; Pontecorvo, L.; Primavera, M.; Rebuzzi, D.; Richter, R.; Rimoldi, A.; Rosati, S.; Rothberg, J.; Sakamoto, H.; Salvatore, D.; Sampsonidis, D.; Santonico, R.; Sasaki, O.; Schricker, A.; Schuh, S.; Schune, P.; Shoa, M.; Skvorodnev, N.; Sliwa, K.; Solfaroli Camillocci, E.; Spagnolo, S.; Spogli, Luca; Strauss, E.; Sugaya, Y.; Tanaka, S.; Tarem, S.; Taylor, F. E.; Todorova, S.; Trigger, I.; Tsiafis, I.; Tsipolitis, G.; Valderanis, Ch.; Valente, P.; Vandelli, W.; van der Graaf, H.; Vari, R.; Veneziano, S.; Ventura, A.; Ventura, S.; Vermeulen, J.; Vlachos, S.; Vreeswijk, M.; Yasu, Y.; Wellenstein, H.; Werneke, P.; Wijnen, T.; Wolter, M.; Wotschack, J.; Woudstra, M.; Zema, F.; Zhao, Z.; Zhemchugov, A.; Zhou, B.; Zimmerman, S. 2009-01-11 Nuclear Instruments & Methods in Physics Research. Section A 598 400-415 In 2004, a combined system test was performed in the H8 beam line at the CERN SPS with a setup reproducing the geometry of sectors of the ATLAS Muon Spectrometer, formed by three stations of Monitored DriftTubes (MDT). The full ATLAS analysis chain was used to obtain the results presented in this paper. The basic design performances of the Muon Spectrometer were verified. The stability of MDT calibration constants, the alignment system using optical devices and high energy tracks, as well as the intrinsic sagitta resolution of the Muon Spectrometer were studied and found to agree with expectations. The reconstruction of muon tracks using the combined information from both the Inner Detector and the Muon Spectrometer are also presented.

ARGO-YBJ constraints on very high energy emission from GRBs

2009-07-31T22:00:00Z

ARGO-YBJ constraints on very high energy emission from GRBs Aielli, G.; Bacci, Cesare; Bartoli, B.; Bernardini, P.; Bi, X. J.; Bleve, C.; Branchini, Paolo; Budano, Antonio; Bussino, Severino; Calabrese Melcarne, A. K.; Camarri, P.; Cao, Z.; Cappa, A.; Cardarelli, R.; Catalanotti, S.; Cattaneo, C.; Celio, Paola; Chen, S. Z.; Chen, Y.; Cheng, N.; Creti, P.; Cui, S. W.; Dai, B. Z.; D'Ali Staiti, G.; Danzengluobu; Dattoli, M.; De Mitri, I.; D'Ettorre Piazzoli, B.; De Vincenzi, Mario; Di Girolamo, T.; Ding, X. H.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Galeazzi, Fulvio; Galeotti, P.; Gargana, Riccardo; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Huang, Q.; Iacovacci, M.; Iuppa, R.; James, Irina; Jia, H. Y.; Labaciren; Li, H. J.; Li, J. Y.; Li, X. X.; Liberti, B.; Liguori, G.; Liu, C.; Liu, C. Q.; Liu, M. Y.; Liu, J.; Lu, H.; Ma, X. H.; Mancarella, G.; Mari, Stefano Maria; Marsella, G.; Martello, D.; Mastroianni, S.; Meng, X. R.; Montini, Paolo; Ning, C. C.; Pagliaro, A.; Panareo, M.; Perrone, L.; Pistilli, Pio; Qu, X. B.; Rossi, E.; Ruggieri, Federico; Saggese, L.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Stanescu, Cristian; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, B.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xu, B.; Xue, L.; Yan, Y. X.; Yang, Q. Y.; Yang, X. C.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, JiLong; Zhang, JianLi; Zhang, L.; Zhang, P.; Zhang, X. Y.; Zhang, Y.; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Zizzi, G. 2009-08 Astroparticle Physics 32 47-52 The ARGO-YBJ (Astrophysical Radiation Ground-based Observatory at YangBajing) experiment is designed for very high energy gamma-astronomy and cosmic ray researches. Due to the full coverage of a large area(5600 m(2)) with resistive plate chambers at a very high altitude (4300m a.s.l.), the ARGO-YBJ detector is used to search for transient phenomena, such as Gamma-ray bursts (GRBs). Because the ARGO-YBJ detector has a large field of view (similar to 2 sr) and is operated with a high duty cycle (>90%), it is well suited for GRB surveying and can be operated in searches for high energy GRBs following alarms set by satellite-borne observations at lower energies. In this paper, the sensitivity of the ARGO-YBJ detector for GRB detection is estimated. Upper limits to fluence with 99% confidence level for 26 GRBs inside the field of view from June 2006 to January 2009 are set in the two energy ranges 10-100 GeV and 10 GeV-1 TeV.

A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta ' meson

2009-07-30T22:00:00Z

A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta ' meson Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocchetta, Simona; Bossi, F.; Branchini, Paolo; Capon, G.; Capussela, T.; Ceradini, Filippo; Ciambrone, P.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, Biagio; Dreucci, M.; Felici, G.; Fiore, S.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Graziani, Enrico; Jacewicz, M.; Lanfranchi, G.; Lee-Franzini, J.; Martini, M.; Massarotti, P.; Meola, S.; Miscetti, S.; Moulson, M.; Mueller, S.; Murtas, F.; Napolitano, M.; Nguyen, Federico; Palutan, M.; Pasqualucci, E.; Passeri, Antonio; Patera, V.; Santangelo, P.; Sciascia, B.; Spadaro, T.; Testa, M.; Tortora, Ludovico; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G. 2009-07-31 Journal of High Energy Physics 7 105 We update the values of the eta-eta' mixing angle and of the eta' gluonium content by fitting our measurement R-phi = BR(phi -> etagamma)/BR(phi -> eta gamma) together with several vector meson radiative decays to pseudoscalars (V -> P gamma), pseudoscalar mesons radiative decays to vectors (P -> V gamma) and the eta' -> gamma gamma,pi(0) -> gamma gamma widths. From the fit we extract a gluonium fraction of Z(G)(2) = 0.12 +/- 0.04, the pseudoscalar mixing angle psi(P) = (40.4 +/- 0.6) degrees and the phi - omega mixing angle psi(V)= (3.32 +/- 0.09)degrees. Z(G)(2) and psi(P) are fairly consistent with those previously published. We also evaluate the impact on the eta' gluonium content determination of future experimental improvements of the eta' branching ratios and decay width.