Search

Your search keyword '"L., Venturelli"' showing total 293 results
Start Over Author "L., Venturelli"
293 results on '"L., Venturelli"'

101. Spin-parity analysis of the final state π+π−π0 from annihilation at rest in hydrogen targets at three densities

Author

Nicola Semprini-Cesari, Alberto Masoni, Paola Salvini, S. Costa, D. Calvo, V. Vagnoni, M. Poli, G. Vedovato, A. Saino, C. Scoglio, Roberto Spighi, A. Grasso, Mauro Villa, Umberto Marini Bettolo Marconi, Paola Gianotti, M.P. Bussa, A. Vitale, A. Collamati, L. Filippi, Stefania Vecchi, O. Y. Denisov, C. Damiani, L. Ferrero, L. Fava, Michelangelo Agnello, Antonio Ferretti, V. Filippini, I. Massa, O.E. Gorchakov, G. Maron, V.I. Tretyak, C. Cavion, S. De Castro, Aldo Zenoni, A.M. Rozhdestvensky, A M Rosca, D. Galli, A. Maggiora, S. Marcello, M.G. Sapozhnikov, Antonietta Donzella, V. Lucherini, R. Garfagnini, L. Busso, Tullio Bressani, Bruno Minetti, F. Nichitiu, U. Gastaldi, S. Serci, P.P. Temnikov, Alberto Rotondi, L. Valacca, Massimo Piccinini, C. Petrascu, Adriano Fontana, D. Parena, A. Vezzani, L. Venturelli, V.G. Ableev, Paolo Montagna, G. Pauli, F. Vigotti, L. Vannucci, Armando Lanaro, G. Puddu, Elena Botta, E. Rossetto, Marco Bruschi, M. Capponi, R. A. Ricci, G. L. Usai, D. Panzieri, M. Corradini, S.N. Prakhov, F. Tosello, S. Tessaro, P. Cerello, Felice Iazzi, Corrado Cicalo, A. Bertin, A. Filippi, R. Donà, Antonio Zoccoli, F. Balestra, C. Guaraldo, G. Bendiscioli, L. Santi, Alessandro Feliciello, Benedetto Giacobbe, and E. Lodi Rizzini

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Amplitude, Hydrogen, chemistry, Partial wave analysis, Pi, chemistry.chemical_element, Parity (physics), Vector meson, Atomic physics
Abstract

The partial wave analysis of the reaction p p → π + π − π 0 at rest has been performed for the first time by using high-statistics data sets collected in hydrogen targets at three different densities. The different mixtures of partial waves corresponding to our samples allow a reliable determination of each contribution. This technique is crucial in the identification of the exotic candidate f2(1565) which can be produced by 1S0, 3P1 and 3P2 initial states. The amplitude analysis was performed in the frame of the K-Matrix and P-Vector approach. It requires presence of the exotic candidates f0(1500) and f2(1565) with the following masses and total widths: (1449 ± 20)MeV, (114 ± 30)MeV and (1507 ± 15)MeV, (130 ± 20)MeV respectively. In addition to f0(980), f0(1300) f2(1270) and ϱ(770), a clear evidence of I = 1, JP = 1− signal, which we identify with ϱ(1450), is obtained.

Published
1997

102. New data on Δ++-baryon production in annihilation at rest

Author

A. Bertin, M. Bruschi, M. Capponi, A. Collamati, S. De Castro, R. Donà, A. Ferretti, D. Galli, B. Giacobbe, U. Marconi, M. Piccinini, M. Poli, N. Semprini Cesari, R. Spighi, S. Vecchi, A. Vezzani, F. Vigotti, M. Villa, A. Vitale, A. Zoccoli, M. Corradini, A. Donzella, E. Lodi Rizzini, L. Venturelli, A. Zenoni, C. Cicalò, A. Masoni, G. Puddu, S. Serci, P. Temnikov, G. Usai, O. Gortchakov, S. Prakhov, A. Rozhdestvensky, M. Sapozhnikov, V. Tretyak, P. Gianotti, C. Guaraldo, A. Lanaro, V. Lucherini, F. Nichitiu, C. Petrascu, A. Rosca, V. Ableev, C. Cavion, U. Gastaldi, M. Lombardi, G. Maron, L. Vannucci, G. Vedovato, G. Bendiscioli, V. Filippini, A. Fontana, P. Montagna, A. Rotondi, A. Saino, P. Salvini, C. Scoglio, F. Balestra, E. Botta, T. Bressani, M.P. Bussa, L. Busso, D. Calvo, P. Cerello, S. Costa, O. Denisov, L. Fava, A. Feliciello, L. Ferrero, A. Filippi, R. Garfagnini, A. Grasso, A. Maggiora, S. Marcello, D. Panzieri, D. Parena, E. Rossetto, F. Tosello, L. Valacca, G. Zosi, M. Agnello, F. Iazzi, B. Minetti, G. Pauli, S. Tessaro, and L. Santi

Subjects
Physics, Baryon, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Pion, Proton, Deuterium, Analytical chemistry, Invariant mass, Production (computer science)
Abstract

New experimental results on p d annihilation at rest into pions plus a high momentum proton in the final state are discussed. The data sample was collected using the OBELIX spectrometer at the LEAR facility (CERN). The annihilation probabilities, or more precisely the yields (Y) via channels p d → 2π − π + π 0 p and p d → 3π − 2π + π 0 p with proton momenta p > 400 MeV/c have been measured for the first time: Y = (93.2 ± 1.6) × 10−4 and Y = (52.2 ± 1.4) × 10−4, respectively. The signal in the invariant mass distribution of the pπ+ system in the region of the well-known Δ++(1232)-isobar is clearly seen in reactions p d → 2π − π + p , p d → 2π − π + π 0 p , p d → 3π − 2π + p and p d → 3π − 2π + π 0 p . The upper limit on reaction p (Δ − Δ ++ ) → 2π − π + p in the p d annihilation at rest, which could be interpreted as a manifestation of the ΔΔ component of the deuteron, was found to be Y ≤ 6.5 × 10−5 with a 90% confidence level.

Published
1997

103. P̄P partial cross sections at low energy

Author

Maurizio Piccinini, A. Zenoni, Bruno Minetti, R. Spighi, D. Panzieri, I. Massa, S.N. Prakhov, L. Venturelli, V. T. Nomokonov, A. Filippi, M.G. Sapozhnikov, L. Santi, F. Nichitiu, E. Lodi Rizzini, M. Morando, G. V. Margagliotti, G. Pauli, L. Fava, D. Parena, B. Giacobbe, A. Vezzani, A. Lanaro, L. Valacca, C. Scoglio, F. Tosello, Alberto Masoni, V.G. Ableev, P. Gianotti, S. De Castro, A. Saino, M. Capponi, S. Marcello, I. D'Antone, T. Bressani, U. Gastaldi, S. Serci, Paola Salvini, F. Balestra, S. Tessaro, G. Vedovato, E. Rossetto, C. Guaraldo, A. Benedettini, Paolo Montagna, G. Maron, Stefania Vecchi, F. D'Isep, G. Bendiscioli, Alberto Andrighetto, Michelangelo Agnello, N. Mirfakhraee, V.I. Tretyak, A. Collamati, M. Lombardi, L. Busso, N. Semprini Cesari, G. L. Usai, O.Yu. Denisov, Adriano Fontana, E. Botta, D. Calvo, L. Vannucci, A.M. Rozhdestvensky, A. Ferretti, R. Garfagnini, L. Ferrero, Mauro Villa, Felice Iazzi, D. Galli, A. Feliciello, Corrado Cicalo, R. A. Ricci, F. Vigotti, A. Donzella, U. Marconi, M. Poli, V. Filippini, Antonio Zoccoli, M.P. Bussa, A. Vitale, S. Costa, A. Grasso, C. Cavion, G. Puddu, Alberto Rotondi, C. Petrascu, A. Rosca, P. Cerello, Marco Bruschi, V. Lucherini, R. Donà, G. Zosi, M. Corradini, Petar Temnikov, A. Maggiora, and A. Bertin

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Pair production, Annihilation, Meson, Scattering, Protonium, Branching fraction, Hadron, Scattering length, Atomic physics, Atomic and Molecular Physics, and Optics
Abstract

New measurements of the pp total annihilation cross-section at very low momenta (around 50 MeV/c) confirm the previous results obtained by the OBELIX collaboration. The measured values are in general agreement with a scattering length approximation of the annihilation cross-section where the pp scattering lengths are obtained from measurement of the protonium shifts and widths and which accounts for the Coulomb interaction. Partial annihilation cross-sections and annihilation frequencies for some channels have been measured too. The values of the total and partial cross sections at the lowest p momentum show an unexpected behaviour

Published
1997

104. Study of the isovector scalar mesons in the channel p̄pK±KS0π‡ at three hydrogen target densities

Author

Felice Iazzi, Michelangelo Agnello, D. D'Isep, S.N. Prakhov, M. Capponi, A. Vezzani, A. Grasso, S. De Castro, V. Lucherini, Andrea Fontana, Antonio Zoccoli, F. Vigotti, Antonio Ferretti, C. Guaraldo, A. Feliciello, V.I. Tretyak, G. Puddu, M. Morando, S. Serci, A. Filippi, C. Scoglio, S. Tessaro, A. Maggiora, R. Donà, M.P. Bussa, Paolo Montagna, Stefania Vecchi, P. Gianotti, M. Corradini, Paola Salvini, Nicola Semprini-Cesari, A. Benedettini, R. Garfagnini, S. Costa, F. Balestra, F. Nichitiu, E. Lodi Rizzini, G. L. Usai, C. Cicalo, A. Saino, I. Massa, G. Bendiscioli, S. Marcello, Umberto Marini Bettolo Marconi, G. Pauli, Elena Botta, V. Filippini, L. Fava, A M Rosca, Mauro Villa, A. Collamati, G. V. Margagliotti, Tullio Bressani, C. Cavion, Aldo Zenoni, Alberto Masoni, U. Gastaldi, L. Busso, Marco Bruschi, Roberto Spighi, N. Mirfakhraee, D. Calvo, P.P. Temnikov, Gianfranco Zosi, I. D'Antone, L. Valacca, P. Cerello, Antonietta Donzella, L. Venturelli, L. Santi, A. Vitale, A. Bertin, L. Ferrero, O. Y. Denisov, Benedetto Giacobbe, Alberto Rotondi, C. Petrascu, V.P. Nomokonov, D. Parena, D. Panzieri, F. Tosello, E. Rossetto, M.G. Sapozhnikov, V.G. Ableev, M. Lombardi, D. Galli, A.M. Rozhdestvensky, Massimo Piccinini, Armando Lanaro, M. Poli, G. Vedovato, L. Vannucci, G. Maron, and Bruno Minetti

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Particle decay, Annihilation, Pair production, Meson, Isovector, Branching fraction, Hadron, Invariant mass, Atomic physics, Atomic and Molecular Physics, and Optics
Abstract

The study of the I = 1, 0 ++ states with the OBELIX detector in the channel pp → K ±K 0 sπ ∓ at three different target densities is reported. We discuss in particular the results about a o (980) and the evidence of an extra scalar state with mass 1.29 ± 0.01 GeV/c 2 and width 0.080 ± 0.005 GeV/c 2

Published
1997

105. Results on spin-parity analysis of n̄p → π+π−π+ in flight

Author

E. Rossetto, Tullio Bressani, U. Gastaldi, M. Capponi, N. Semprini Cesari, L. Santi, D. Panzieri, S. Costa, P. Cerello, A. Bertin, Antonio Ferretti, A. Feliciello, Alberto Masoni, I. Massa, D. Calvo, Bruno Minetti, Michelangelo Agnello, L. Ferrero, S. Marcello, A. Filippi, S.N. Prakhov, Antonio Zoccoli, M. Lombardi, R. Donà, M. Morando, P.P. Temnikov, Gianfranco Zosi, A. Vezzani, L. Valacca, L. Fava, D. Galli, S. De Castro, M.G. Sapozhnikov, V. Lucherini, Alberto Rotondi, F. D'Isep, G. Belli, C. Scoglio, C. Petrascu, D. Parena, A. Saino, Umberto Marini Bettolo Marconi, A M Rosca, Mauro Villa, G. V. Margagliotti, S. Serci, F. Tosello, V.G. Ableev, N. Mirfakhraee, M. Corradini, S. Tessaro, L. Venturelli, G. Maron, M. Poli, V. Filippini, G. Vedovato, Roberto Spighi, P. Gianotti, F. Nichitiu, C. Cavion, Elena Botta, L. Vannucci, Aldo Zenoni, E. Lodi Rizzini, G. L. Usai, C. Guaraldo, M.P. Bussa, Andrea Fontana, Stefania Vecchi, R. A. Ricci, G. Pauli, Felice Iazzi, G. Bendiscioli, Alberto Andrighetto, V.I. Tretyak, A. Maggiora, A. Collamati, A. Vitale, A.M. Rozhdestvensky, F. Balestra, C. Cicalo, Massimo Piccinini, F. Vigotti, Marco Bruschi, G. Puddu, R. Garfagnini, Antonietta Donzella, Armando Lanaro, Benedetto Giacobbe, Paola Salvini, I. D'Antone, A. Benedettini, O. Gortchakov, A. Grasso, O. Y. Denisov, L. Busso, and Paolo Montagna

Subjects
Physics, Nuclear and High Energy Physics, Angular momentum, Annihilation, Pion, Pair production, Meson, Hadron, Elementary particle, Invariant mass, Atomic physics, Atomic and Molecular Physics, and Optics
Abstract

We report in this paper the results of the study of the ƒ 0 (1500)/ƒ 2 (1565) resonances in the in-flight annihilation reaction np → 2 π + π − , taking into account a possible dependence on the n momentum.

Published
1997

106. A search for axial vectors in annihilations at rest in gaseous hydrogen at NTP

Author

L. Fava, R. Spighi, S.N. Prakhov, S. De Castro, D. Galli, A. Filippi, R. Donà, R. Garfagnini, F. Tosello, G. L. Usai, Marco Bruschi, S. Tessaro, S. Serci, A. Lai, Nicola Semprini-Cesari, Elena Botta, Michelangelo Agnello, Piergiorgio Cerello, V.I. Tretyak, A. Saino, L. Musa, S. Costa, A. Maggiora, Maurizio Piccinini, V. Lucherini, O.E. Gorchakov, A. Vezzani, A M Rosca, L. Valacca, F. Balestra, O. Y. Denisov, L. Venturelli, S. Marcello, M. Capponi, Petar Temnikov, Tullio Bressani, A. Grasso, A. Bertin, U. Gastaldi, C. Scoglio, Antonio Zoccoli, G. Bendiscioli, V. Filippini, F. Vigotti, Alberto Masoni, U. Marconi, D. Calvo, Mauro Villa, Paola Salvini, A. Vitale, L. Busso, C. Cavion, L. Santi, Adriano Fontana, Aldo Zenoni, C. Guaraldo, A. Ferretti, A. Collamati, Felice Iazzi, L. Vannucci, Corrado Cicalo, Paolo Montagna, M.P. Bussa, Stefania Vecchi, Antonietta Donzella, B. Giacobbe, M. Corradini, F. Nichitiu, G. Pauli, A. Feliciello, L. Ferrero, Alberto Rotondi, C. Petrascu, D. Parena, E. Lodi Rizzini, M.G. Sapozhnikov, V.G. Ableev, M. Lombardi, A.M. Rozhdestvensky, D. Panzieri, G. Puddu, E. Rossetto, Armando Lanaro, M. Poli, G. Vedovato, Paola Gianotti, Bruno Minetti, and G. Maron

Subjects
Pseudoscalar, Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Gaseous hydrogen, Pi
Abstract

The study of the K±Kmiss0π∓π+π− channel (7016 events), from p p annihilations in a gaseous hydrogen target at NTP, with the OBELIX spectrometer at LEAR (CERN), is presented. A spin-parity analysis provides evidence for two axial vectors, one in the low K K π mass region, the well established f1(1285), decaying to a0(980)π, the second, the 1++ component of the old puzzling E l , the f1(1420), decaying mainly to K ∗ K , seen for the first time in p p annihilation at rest. The analysis confirms the dominant production of the pseudoscalar η(1405), decaying mainly to (Kπ) S K , and the existence of a second pseudoscalar in the same mass region, the η(1460), decaying mainly to K ∗ K .

Published
1997

107. [Untitled]

Author

J.P. Merrison, R.A. Lewis, Alberto Rotondi, G. Testera, Maurizio Piccinini, M.R. Masullo, T. Yamazaki, J. S. Hangst, Dezso Horvath, Yasunori Yamazaki, T. Goldman, M. Macri, Gerald A. Smith, Nicola Semprini-Cesari, E. Widmann, Georg Bollen, Michael Doser, S.P. Møller, M. Charlton, L. Venturelli, C. L. Cesar, D. Zanello, Michael H. Holzscheiter, G. Torelli, K. Kirsebom, Michael Martin Nieto, Ryugo S. Hayano, E. Lodi-Rizzini, Helge Knudsen, Antonio Zoccoli, R.J. Hughes, D. DePedis, A. Bertin, Renato Fedele, V. Lagomarsino, F. Galluccio, N. S. P. King, E. Uggerhøj, Paola Salvini, G.L. Morgan, U. Marconi, John Eades, M. Corradini, Marco Bruschi, G. Manuzio, A. Vitale, X. Feng, V.G. Vaccaro, Clifford M Surko, Rosa Poggiani, G. Rouleau, R. Landua, G. Laricchia, and G. Bendiscioli

Subjects
Nuclear physics, Physics, Physics::General Physics, Rydberg constant, Antiproton, CPT symmetry, Magnetic trap, Antimatter, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Antihydrogen, Positronium, Lamb shift
Abstract

The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter. In recent years, impressive progress has been achieved at the Low Energy Antiproton Ring (LEAR) at CERN in capturing antiprotons in specially designed Penning traps, in cooling them to energies of a few milli-electron volts, and in storing them for hours in a small volume of space. Positrons have been accumulated in large numbers in similar traps, and low energy positron or positronium beams have been generated. Finally, steady progress has been made in trapping and cooling neutral atoms. Thus the ingredients to form antihydrogen at rest are at hand. We propose to investigate the different methods to form antihydrogen at low energy, and to utilize the best of these methods to capture a number of antihydrogen atoms sufficient for spectroscopic studies in a magnetostatic trap. Once antihydrogen atoms have been captured at low energy, spectroscopic methods can be applied to interrogate their atomic structure with extremely high precision and compare it to its normal matter counterpart, the hydrogen atom. Especially the 1S-2S transition, with a lifetime of the excited state of 122 ms and thereby a natural linewidth of 5 parts in 1016, offers in principle the possibility to directly compare matter and antimatter properties at a level of 1 part in 1018. Additionally, comparison of the gravitational masses of hydrogen and antihydrogen, using either ballistic or spectroscopic methods, can provide direct experimental tests of the Weak Equivalence Principle for antimatter at a high precision.

Published
1997

108. Experimental apparatus for annihilation cross-section measurements of low energy antiprotons

Author

Aldo Mozzanica, M. Leali, Masaki Hori, Matteo Ferroni, N. Zurlo, L. Venturelli, Ryugo S. Hayano, Camilla Baratto, E. Vallazza, M. Corradini, M. Prest, Alberto Vomiero, Valerio Mascagna, K. Todoroki, and E. Lodi Rizzini

Subjects
antinucleon-nucleon interaction, Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Annihilation, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, antiproton decelerator, Antiproton Decelerator, Experimental physics, Nuclear physics, Cross section (physics), Low energy, Antiproton, scintillating tracker, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, Instrumentation
Abstract

The nuclear physics program of the ASACUSA experiment at the Antiproton Decelerator (AD) at CERN is concerned with the measurements of antiproton-nuclei cross-sections at low energies (from 5.3 MeV down to the 100 keV region). These measurements are expected to contribute to understand the dynamics of the annihilation process. We give here a full description of the experimental apparatus used for the measurements at 5.3 MeV.

Published
2013

109. Two-photon laser spectroscopy of antiprotonic helium and the antiproton-electron mass ratio

Author

B. Juhász, S. Friedreich, Nicola Zurlo, L. Venturelli, Dezso Horvath, Andreas Dax, Eberhard Widmann, T. Pask, D. Barna, Anna Sótér, Masaki Hori, and Ryugo S. Hayano

Subjects
Nuclear physics, Physics, Proton, Antiproton, Electron rest mass, Physics::Atomic Physics, Electron, Mass ratio, Atomic physics, Nuclear Experiment, Spectroscopy, Antiprotonic helium, Atomic mass
Abstract

We report our latest results from our two-photon spectroscopy of antiprotonic helium (a bound state of a helium nucleus, an electron and an antiproton). By measuring three transition frequencies with a precision of 2.3−5×10−9 and comparing these to 3-body QED calculations, we derived the antiproton-electron mass ratio 1,836.1526736(23),which agrees with the proton-electron mass ratio (known to a three-times better precision) within the errors. Since the (anti)proton's atomic mass is known to a better precision than that of the electron, assuming mp = mp this result can be used to determine the electron's atomic mass as me=0.0005485799091(7) u.

Published
2013

110. Towards the production of anti-hydrogen beams

Author

K. S. Tanaka, A. Mohri, Yugo Nagata, Yasuyuki Matsuda, Y. Enomoto, Yasuyuki Nagashima, Naofumi Kuroda, Yoshio Kanai, Hiroyuki A. Torii, B. Juhász, Yasunori Yamazaki, Nicola Zurlo, K. Fujii, M. Leali, M. Otsuka, Valerio Mascagna, D. J. Murtagh, Koji Michishio, H. Imao, S. Van Gorp, M. Corradini, Stefan Ulmer, E. Lodi-Rizzini, Hiroyuki Higaki, C. Kim, and L. Venturelli

Subjects
Condensed Matter::Quantum Gases, Physics, anti-hydrogen beam, non-neutral plasma, Field (physics), Hydrogen, hyperfine structure, chemistry.chemical_element, anti-hydrogen, Magnetic field, Physics and Astronomy (all), chemistry, Antiproton, Antimatter, Physics::Atomic Physics, Atomic physics, Antihydrogen, Hyperfine structure, Beam (structure)
Abstract

Recently, the production of low energy anti-hydrogen atoms in the cusp trap with the use of 150eV antiproton beams from the MUSASHI trap was reported. The purpose of producing low energy anti-hydrogen atoms in a cusped magnetic field is to extract a polarized anti-hydrogen beam to a field free region, so that the hyperfine structure of anti-hydrogen atoms can be measured.

Published
2013

111. Experimental antiproton nuclear stopping power inH2andD2

Author

C. Guaraldo, M. Morando, V. Filippini, Antonietta Donzella, Elena Botta, C. Cavion, Michelangelo Agnello, R.A. Ricci, F. Tosello, S. Tessaro, M. Capponi, N. Semprini Cesari, L. Santi, G. Bendiscioli, M. Lombardi, Paola Salvini, Mauro Villa, L. Ferrero, D. Galli, Paolo Montagna, M.G. Sapozhnikov, Alessandro Feliciello, E. Rossetto, Alberto Masoni, Bruno Minetti, V.G. Ableev, D. Calvo, S. De Castro, A. Grasso, Alberto Rotondi, Roberto Spighi, F. Vigotti, I. D'Antone, C. Petrascu, D. Parena, S. Costa, S. Serci, Felice Iazzi, L. Busso, A. Vitale, Corrado Cicalo, F. Balestra, Antonio Zoccoli, O.E. Gorchakov, R. Garfagnini, U. Marconi, A M Rosca, Armando Lanaro, D. Panzieri, S. Marcello, O.Yu. Denisov, A.M. Rozhdestvensky, Tullio Bressani, Massimo Piccinini, G. Vedovato, U. Gastaldi, G. Puddu, Paola Gianotti, G.L. Usai, M. Corradini, L. Vannucci, S.N. Prakhov, F. Nichitiu, A. Maggiora, G. Pauli, V. Lucherini, L. Venturelli, A. Zenoni, Benedetto Giacobbe, M. Poli, E. Lodi Rizzini, Marco Bruschi, A. Filippi, W. Tretyak, P. Cerello, A. Bertin, A. Vezzani, M.P. Bussa, Stefania Vecchi, P.P. Temnikov, Gianfranco Zosi, Adriano Fontana, A. Saino, and Antonio Ferretti

Subjects
Physics, Baryon, Nuclear physics, Antiparticle, Antiproton, Computer Science::Information Retrieval, Antimatter, Hadron, Stopping power (particle radiation), Elementary particle, Nucleon, Atomic and Molecular Physics, and Optics
Abstract

Data about antiprotons slowing down in gaseous targets at very low energies ({ital E}{lt}1 keV) show that the stopping power in D{sub 2} is lower than in H{sub 2}; the right way to explain this behavior seems to be through a nuclear stopping power derived from the classical Rutherford formula. {copyright} {ital 1996 The American Physical Society.}

Published
1996

112. decay to in annihilation at rest

Author

A. Lai, S. De Castro, Armando Lanaro, Tullio Bressani, U. Gastaldi, Mauro Villa, Paola Salvini, Nicola Semprini-Cesari, L. Musa, S. Costa, G. Puddu, B. Cereda, O.Yu. Denisov, S. Serci, S. Marcello, L. Santi, M. Morando, A.M. Rozhdestvensky, N. Mirfakhrai, A. Filippi, Michelangelo Agnello, Paolo Montagna, M.P. Bussa, D. Galli, G. Maron, Massimo Piccinini, M.G. Sapozhnikov, L. Ferrero, Stefania Vecchi, Elena Botta, E. Rossetto, Alberto Rotondi, L. Venturelli, Alberto Masoni, C. Petrascu, D. Parena, A. Feliciello, D. Calvo, G. Bendiscioli, Gianfranco Zosi, A. Grasso, Petar Temnikov, D. Panzieri, V.G. Ableev, Felice Iazzi, Antonietta Donzella, M. Poli, Corrado Cicalo, L. Busso, A. Bertin, A. Vezzani, G. L. Usai, Adriano Fontana, Bruno Minetti, Paola Gianotti, R. Garfagnini, V.I. Tretyak, Benedetto Giacobbe, C. Guaraldo, F. Tosello, S. Tessaro, A. Maggiora, E. Lodi Rizzini, F. Vigotti, V. Lucherini, F. Balestra, Antonio Ferretti, Marco Bruschi, Roberto Spighi, A. Saino, A. Vitale, A M Rosca, Antonio Zoccoli, V. Filippini, C. Cavion, Aldo Zenoni, Umberto Marini Bettolo Marconi, M. Corradini, F. Nichitiu, G. Pauli, and Piergiorgio Cerello

Subjects
Nuclear physics, Pseudoscalar, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Large Hadron Collider, Spectrometer, Partial wave analysis, Dalitz plot, Resonance, Bar (unit)
Abstract

The results of the analysis of 3940 (K K π)ππ events from a sample of 18 millions p p annihilations in the liquid hydrogen target of the OBELIX spectrometer at LEAR (CERN) are presented. The presence of two pseudoscalar states at 1.416±0.002GeV/c2, with width 0.050±0.004GeV/c2, and at 1.46±0.01GeV/c2, with width 0.105±0.015GeV/c2, is established. The lighter mass resonance decays mainly to K K π , possibly with final state interactions and a small contribution coming from a0π. The higher mass 0−+ state, which is seen for the first time in p p annihilation at rest, decays only to K ∗ K . Masses, widths and decay modes are in agreement with the analysis of J Ψ radiative decay performed by the Mark III Collaboration. From the fit the G-parity was determined to be +1. The dominant three-body decay mode of the lighter pseudoscalar is observed for the first time in this measurement.

Published
1995

113. Measurements of the annihilation at rest

Author

S. Costa, R. Spighi, A. Masoni, Elena Botta, Felice Iazzi, S. Marcello, S. De Castro, A. Filippi, Paola Salvini, F. Balestra, Corrado Cicalo, R. A. Ricci, Maurizio Piccinini, G. Puddu, Sergio Serci, Michelangelo Agnello, M. Capponi, M. Poli, Tullio Bressani, M. Lombardi, Piergiorgio Cerello, U. Gastaldi, G. Vedovato, V. Lucherini, M.G. Sapozhnikov, A. Saino, D. Calvo, A. Maggiora, V.I. Tretyak, G. Maneva, Paolo Montagna, C. Guaraldo, O.E. Gorchakov, B. Cereda, R. Garfagnini, P. Boccaccio, M.P. Bussa, Paola Gianotti, F. Nichitiu, V.G. Ableev, F. Tosello, S. Tessaro, M. Morando, Stefania Vecchi, Gianfranco Zosi, E. Rossetto, G. L. Usai, L. Vannucci, Adriano Fontana, G. Pauli, L. Ferrero, A. Feliciello, Armando Lanaro, S.N. Prakhov, L. Busso, L. Santi, A. Vitale, D. Galli, Petar Temnikov, Mauro Villa, G. V. Margagliotti, Antonietta Donzella, D. D'Isep, Bruno Minetti, Alberto Rotondi, E. Lodi Rizzini, B. Giacobbe, A. Bertin, Nicola Semprini-Cesari, O.Yu. Denisov, D. Panzieri, V. Filippini, A.M. Roshdestvensky, A. Grasso, Aldo Zenoni, G. Bendiscioli, Marco Bruschi, L. Fava, U. Marconi, G. Maron, L. Venturelli, and Antonio Zoccoli

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Nuclear magnetic resonance, Analytical chemistry
Abstract

The measurement of different reactions of p d annihilation at rest in a gaseous target has been performed using the OBELIX spectrometer at LEAR (CERN). A strong deviation from the OZI-rule prediction was found from the measurement of the ratio R = φπ ωπ in two regions of proton momenta, P c and P > 400 MeV/ c : R( φπ − ωπ − ) = (133 ± 26) × 10 −3 and (113 ± 30) × 10 −3 , respectively. These values are about 30 times greater than the theoretical prediction. For the first time the excitation of the †-resonance was observed among the final-state products of p d annihilation. The existence of a broad enhancement in the 4π invariant mass at m ≈ 1480 MeV, seen in previous experiments, was confirmed. A ≈ 100 MeV downward shift of the bump position, when the proton momentum increased up to P > 400 MeV/ c , was also observed, while the positions of ω, ϱ and f 2 (1270) did not change with the proton momentum. The following branching ratios were measured: BR( p d → π − φ p ) = (6.62 ± 0.49) × 10 −4 , for P c ; BR( p d → π − φ p ) = (0.95 ± 0.22) × 10 −4 , for P > 400 MeV/ c ; BR( p d → π − ω p ) = (49.7 ± 8.9) × 10 −4 , for P c ; BR( p d → π − ω p ) = (8.38 ± 1.09) × 10 −4 , for P > 400 MeV/ c ; BR( p d → 2π − π + p ) = (150 ± 6) × 10 −4 , for P c ; BR( p d → 2π − π + p ) = (16.6 ± 0.9) × 10 −4 , for P > 400 MeV/ c ; BR( p d → 3π − 2π + p ) = (326 ± 12) × 10 −4 , for P c ; BR( p d → 3π − 2π + p ) = (44 ± 7) × 10 −4 , for P > 400 MeV/ c ; BR( p d → Λ K + π − ) = (0.96 ± 0.19) × 10 −4 , for P > 400 MeV/ c ; BR( p d → Λ K + π − π 0 ) = (3.5 ± 0.8) × 10 −4 , for P > 400 MeV/ c ; BR( p p → 2π − 2π + ) = (540 ± 20) × 10 −4 ; BR( p p → 3π − 3π + ) = (251 ± 21) × 10 −4 .

Published
1995

114. FINUDA and hypernuclei production at DAωNE

Author

N. Colonna, L. Fiore, Rinaldo Rui, S. Marcello, M. Bertani, A. Donzella, Felice Iazzi, D. R. Gill, A. Sharma, Paola Salvini, A. Olin, L. Venturelli, E. Rossetto, D. Calvo, Bruno Minetti, S. Sarwar, C. Guaraldo, S. Yen, S. Bianco, S. Costa, Paolo Montagna, G. D’Erasmo, N. Grion, Elena Botta, V. Lucherini, Paolo Camerini, Michelangelo Agnello, Armando Lanaro, G. R. Smith, P. Gianotti, V. Paticchio, A. Feliciello, L. Busso, Tullio Bressani, A. Filippi, E.M. Fiore, M. Corradini, V. Filippini, Aldo Zenoni, E. Lodi-Rizzini, C. Cattaneo, Alberto Rotondi, F.L. Fabbri, and A. Pantaleo

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Positron, Luminosity (scattering theory), law, Electron, Collider, Linear particle accelerator, law.invention
Abstract

The DAωNE project at the Laboratori Nazionali di Frascati (LNF) is an e + e − collider with electron and positron beams accelerated to 510 MeV by a Linac injector. DAωNE is designed to reach a top luminosity L ∼ 10 33 cm −2 s −1 , that is, to produce ∼4×10 3 ω (1020) s −1 . The hypernuclear research program at DAωNE relies on low-energy kaons, ∼ 16MeV, being produced by ω-meson decays at rest: ω → K − K + with a B.R.∼49%. In the initial stage, DAωNE will operate at a L ∼ 10 32 cm −2 s −1 , however the number of ω produced, and the large geometrical acceptance of the FINUDA detector, ∼ 3 sr , will allow a strong hypernuclear physics program to be pursued.

Published
1995

115. Antiproton Slowing Down inH2and He and Evidence of Nuclear Stopping Power

Author

Tullio Bressani, M. Corradini, L. Ferrero, Alberto Rotondi, Bruno Minetti, F. Tosello, S. Tessaro, F. Nichitiu, E. Botta, E. Rossetto, M.P. Bussa, G. Pauli, G. Puddu, Stefania Vecchi, S. De Castro, B. Cereda, S. Serci, A. Grasso, D. Galli, C. Guaraldo, N. Semprini Cesari, M.G. Sapozhnikov, L. Santi, Roberto Spighi, D. Panzieri, L. Venturelli, A. Vitale, Alessandro Feliciello, U. Marconi, Paola Gianotti, V. Filippini, P. Cerello, Mauro Villa, S. Costa, Paola Salvini, L. Busso, Antonio Zoccoli, R. Garfagnini, A. Bertin, M. Morando, Aldo Zenoni, A. Filippi, A.M. Rozhdestvensky, G. Belli, Paolo Montagna, V.I. Tretyak, Benedetto Giacobbe, V. Lucherini, E. Lodi Rizzini, Armando Lanaro, Antonietta Donzella, M. Bruschi, M. Piccinini, S. Marcello, G. Bendiscioli, A. Saino, Felice Iazzi, Corrado Cicalo, G. L. Usai, Michelangelo Agnello, P.P. Temnikov, Adriano Fontana, Alberto Masoni, and D. Calvo

Subjects
Physics, Antiparticle, Annihilation, General Physics and Astronomy, Charged particle, Nuclear physics, Baryon, Antiproton, Antimatter, Physics::Accelerator Physics, Stopping power (particle radiation), Physics::Atomic Physics, Atomic physics, Nuclear Experiment, Nucleon
Abstract

We report stopping powers of hydrogen and helium for antiprotons of kinetic energies ranging from about 0.5 keV to 1.1 MeV. The Barkas effect, i.e., a difference in the stopping power for antiprotons and protons of the same energy in the same material, shows up clearly in either of the gases. Moreover, below [approx]0.5 keV there is indirect evidence for an increase of the antiproton stopping power. This nuclear'' effect, i.e., energy losses in quasimolecular interactions, shows up in fair agreement with theoretical predictions.

Published
1995

116. Antiprotons stopping in xenon

Author

M.P. Bussa, Germano Bonomi, A. Grasso, L. Venturelli, L. Santi, M. Corradini, M.L. Colantoni, F. Balestra, C. Guaraldo, G. Piragino, O.E. Gorchakov, F. Tosello, S. Tessaro, A.M. Rozhdestvensky, M. Maggiora, E. Lodi Rizzini, L. Ferrero, O. Y. Denisov, G. V. Margagliotti, R. Garfagnini, C. Petrascu, S.N. Prakhov, L. Busso, Antonietta Donzella, V.I. Tretyak, A. Maggiora, Andrea Bianconi, Gianfranco Zosi, E., Lodirizzini, A., Bianconi, G., Bonomi, M. P., Bussa, M., Corradini, A., Donzella, L., Venturelli, O. E., Gorchakov, S. N., Prakhov, A. M., Rozhdestvensky, V. I., Tretyak, F., Balestra, L., Busso, M. L., Colantoni, O. Y., Denisov, L., Ferrero, R., Garfagnini, A., Grasso, A., Maggiora, M., Maggiora, G., Piragino, F., Tosello, G., Zosi, Margagliotti, Giacomo, S., Tessaro, and L., Santi

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Cross section (physics), Xenon, Low energy, chemistry, Antiproton, Low density, chemistry.chemical_element, Atomic physics, Hyperfine structure
Abstract

Experimental data on p slowing down at very low energy in a low density (0.2 mbar pressure) Xe target evidence a very low capture cross section with respect to He, H 2 and D 2 in agreement with specific phenomenological previsions by Briggs et al. [Hyperfine Interact. 119 (1999) 235; J. Phys. B 32 (1999) 197].

Published
2001

117. Further evidence for low-energy protonium production in vacuum

Author

P. Montagna, Carlo Canali, Alberto Rotondi, Claude Amsler, Ryugo S. Hayano, P. Genova, Alban Kellerbauer, D. P. van der Werf, L. Venturelli, M. Macri, M. Charlton, V. Lagomarsino, G. Testera, L. V. Jørgensen, C. Regenfus, Adriano Fontana, R. Landua, E. Lodi Rizzini, Alessandro Variola, G. Manuzio, Nicola Zurlo, C. Carraro, and Germano Bonomi

Subjects
Physics, Annihilation, General Physics and Astronomy, Plasma, 01 natural sciences, 010305 fluids & plasmas, Ion, Nuclear physics, Positron, Physics::Plasma Physics, Protonium, Antiproton, 0103 physical sciences, Bound state, Physics::Accelerator Physics, Nuclear Physics - Experiment, Physics::Atomic Physics, Atomic physics, 010306 general physics, Antihydrogen
Abstract

We describe an experiment performed in the ATHENA apparatus in which there is evidence that the antiproton-proton bound state, protonium, has been produced at very low energies in vacuum following the interaction of cold antiprotons with a trapped cloud of molecular hydrogen ions. The latter were confined in a centrifugally separated belt outside a positron plasma used for antihydrogen formation. Studies have been performed at low positron plasma temperatures in which the protonium annihilation signal has been identified along with that from antihydrogen, and we discuss how their contributions can be disentangled. With the positron plasma heated to around 10,000 K the ions become distributed in the positrons, and the majority of the annihilation signal can be explained in terms of protonium formationion, as antihydrogen creation is heavily suppressed. In this case we compare the observed protonium formation rate with expectations from theory and find reasonable accord, when experimental systematics are taken into account. The effect on the annihilation signals of the passage of an electron current through a pre-loaded positron plasma has been studied in detail, and the results are presented here for the first time.

Published
2012

118. Thorotrast: analysis of the time evolution of its α activity concentration, in the 70 years following the chemical purification of Thorium

Author

M. Corradini, N. Zurlo, M. Leali, E. Lodi Rizzini, Andrea Bianconi, and L. Venturelli

Subjects
Radiochemistry, Time Factors, Simulazione, Thorium, Biophysics, Active components, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, General Medicine, Models, Theoretical, Alpha Particles, Excretion, Serie Torio, Thorotrast, Attività in-vivo, chemistry.chemical_compound, chemistry, Activity concentration, Radiology, Nuclear Medicine and imaging, Thorium Dioxide
Abstract

We simulate the α-activity of the Thorium series elements present in the contrast medium named Thorotrast, used until 1960 and cause of certified deaths until today. Assuming, as active components at t = 0 , 232Th and 228Th in the same relative concentration they have in nature, α-activity oscillates for some decades before reaching a stationary value that in absence of biological depletion would be A ST = 24000 Bq/g. Our Montecarlo code generates the nuclear decays of the Thorium series with and without in-vivo biological depletion, arriving to three kinds of results for the activity: 1) Theoretical activity concentration (no biological depletion). Our result is fitted by: A ( t ) = A S T ⋅ { [ 1 − exp ( − t / 10 ) ] + [ exp ( − t / t B ) ( 1 − 0.8 exp ( − t / t A ) ) ] } , with t in years, t A = 1.07 ⋅ 10 − 2 years, and t B = 2.38 years. 2) Weak biological depletion (228Ra/232Th equilibrium activity ratio 0.6, 224Ra/228Ra e.a.r. 0.9, 10% excretion for 220Rn). The ratio of the activity concentration to the theoretical activity concentration is fitted by: A weak ( t ) / A ( t ) = 0.61 + 0.29 exp [ − ( t / 15 ) 2 ] (t in years). 3) Strong biological depletion (228Ra/232Th e.a.r. 0.4, 224Ra/228Ra e.a.r. 0.8, 10% excretion for 220Rn). The ratio of the activity concentration to the theoretical activity concentration is fitted by A strong ( t ) / A ( t ) = 0.44 + 0.4 exp [ − ( t / 13 ) 2 ] (t in years). We also report fluctuation calculation for two cases where standard statistical behavior is not expected.

Published
2012

119. First experimental detection of antiproton in-flight annihilation on nuclei at ∼ 130 keV

Author

K. Todoroki, L. Venturelli, M. Prest, Masaki Hori, Valerio Mascagna, E. Lodi-Rizzini, D. Barna, Nicola Zurlo, Hossein Aghai-Khozani, M. Leali, E. Vallazza, Ryugo S. Hayano, Anna Sótér, M. Corradini, and Takumi Kobayashi

Subjects
Mass number, Physics, Light nucleus, Particle physics, Annihilation, media_common.quotation_subject, Nuclear Theory, Theoretical models, General Physics and Astronomy, Asymmetry, Cosmology, Nuclear physics, Antiproton Decelerator, Antiproton, Nuclear Experiment, media_common
Abstract

The existing data of antinucleon-nucleon and antinucleon-nuclei annihilation cross-sections are confined to energies above about 1MeV. Experimental limitations have prevented till now the lower energies data to be achieved in spite of the interest they represent for theoretical models. One of the unresolved question concerns the antiproton annihilation cross-section measured at LEAR on light nuclei in the MeV region, which show a saturation with the mass number of the target nucleus against any naive expectation. With regard to fundamental cosmology, the knowledge of the annihilation cross-sections at energies below 1MeV can contribute to understand the matter-antimatter asymmetry in the Universe. We present here the experimental demonstration of the feasibility of the measurement of antiproton-nuclei annihilation cross-sections in the 100 keV region.

Published
2012

120. Synthesis of antihydrogen atoms in a CUSP trap

Author

Akihiro Mohri, Yasunori Yamazaki, Yugo Nagata, L. Venturelli, Y. Enomoto, N. Zurlo, H. Imao, Naofumi Kuroda, E. Lodi-Rizzini, H. A. Torii, Koji Michishio, Eberhard Widmann, M. Corradini, Miki Ohtsuka, M. Leali, Valerio Mascagna, K. S. Tanaka, Yasuyuki Kanai, B. Juhász, K. Fujii, C. Kim, Hiroyuki Higaki, Yasuyuki Nagashima, and Yasuyuki Matsuda

Subjects
Condensed Matter::Quantum Gases, Physics, Cusp (singularity), Physics::General Physics, Nuclear and High Energy Physics, CPT symmetry, CPT invariance, Antihydrogen, Atomic beam, Hyperfine splitting, Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Physical and Theoretical Chemistry, Magnetic field, Atomic and Molecular Physics, Atom, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Rotational spectroscopy, Atomic physics, and Optics, Hyperfine structure, Beam (structure)
Abstract

ASACUSA collaboration has been making a path to realize high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atom in flight for stringent test of the CPT symmetry. Recently, we have succeeded in synthesizing our first cold antihydrogen atoms employing a CUSP trap. It is expected that synthesized antihydrogen atoms in the low-field-seeking states are preferentially focused along the cusp magnetic field axis whereas those in the high-field-seeking states are not focused, resulting in the formation of a spin-polarized antihydrogen beam. We report the recent results of antihydrogen atom synthesis and beam production developed with the CUSP trap.

Published
2012

121. Meson spectroscopy withS- andP-wave-dominant initial-state selection in $$\bar pp$$ annihilationannihilation

Author

C. Guaraldo, G. Piragino, Felice Iazzi, D. Yu. Denisov, Paolo Montagna, Corrado Cicalo, P. Cerello, G. Maron, A. Bertin, Roberto Spighi, G. Belli, F. Tosello, S. Tessaro, Bruno Minetti, A. Filippi, A. Vitale, G.C. Bonazzola, G. Bendiscioli, E. Rossetto, Mauro Villa, Tullio Bressani, Paola Salvini, S.N. Prakhov, V. Filippini, M. Lombardi, M. Corradini, L. Fava, P. Boccaccio, U. Gastaldi, C. De Leo, F. Nichitiu, A. Lai, M. Capponi, S. De Castro, Marco Bruschi, G. Pauli, D. Panzieri, G. V. Margagliotti, Alessandro Feliciello, Benedetto Giacobbe, Antonietta Donzella, M.G. Sapozhnikov, A.M. Rozhdestvensky, L. Musa, L. Vannucci, Alberto Andrighetto, M. Morando, V.I. Tretyak, G. Puddu, N. Semprini Cesari, A. Maggiora, B. Cereda, S. Serci, L. Santi, V.G. Ableev, V. Lucherini, L. Ferrero, Massimo Piccinini, A. Grasso, L. Busso, E. Lodi Rizzini, M.P. Bussa, Alberto Rotondi, L. Venturelli, S. Costa, Stefania Vecchi, R. Garfagnini, R. A. Ricci, Umberto Marini Bettolo Marconi, Armando Lanaro, F. Balestra, A. Zenoni, Antonio Zoccoli, M. Poli, T. D. Galli, G. Vedovato, Paola Gianotti, Elena Botta, A. Adamo, I. Massa, S. Marcello, F. D'Isep, P.P. Temnikov, Gianfranco Zosi, Adriano Fontana, A. Saino, Michelangelo Agnello, Alberto Masoni, D. Calvo, and G. L. Usai

Subjects
Physics, Particle physics, Annihilation, Meson, Branching fraction, Nuclear Theory, Detector, State (functional analysis), Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment, Spectroscopy, Computer Science::Databases, Bar (unit)
Abstract

The possibility of selecting the initial angular-momentum state from which antiproton-proton annihilation at rest can occur can be a fundamental tool in meson spectroscopy. With the OBELIX detector different target systems have been employed, ranging fromS-wave toP-wave dominance. The preliminary results both on meson spectroscopy and branching ratio measurements are discussed.

Published
1994

122. The φπ+/ωπ+ ratio from $$\bar np$$ annihilationsannihilations

Author

D. Galli, I. Massa, M. G. Sapozhnikov, F. Tosello, L. Fava, S. Marcello, P. Cerello, Petar Temnikov, S. Tessaro, P. Boccaccio, A. Grasso, S. De Castro, F. D'Isep, Maurizio Piccinini, A. Bertin, C. Guaraldo, U. Marconi, V.I. Tretyak, Mauro Villa, M.P. Bussa, Alberto Masoni, Gianfranco Zosi, S. Serci, Stefania Vecchi, G. Piragino, L. Venturelli, S. Costa, A. Vitale, Felice Iazzi, Corrado Cicalo, M. Morando, D. Calvo, G. V. Margagliotti, L. Ferrero, D. Panzieri, Alessandro Feliciello, A. Filippi, G. Puddu, B. Giacobbe, B. Cereda, Alberto Rotondi, N. Semprini Cesari, M. Lombardi, G. L. Usai, F. Nichitiu, V. Filippini, Bruno Minetti, A. Maggiora, V. Lucherini, L. Santi, Michelangelo Agnello, P. Montagna, Aldo Zenoni, G. Pauli, G.C. Bonazzola, Antonio Zoccoli, Paola Salvini, G. Bendiscioli, M. Capponi, Tullio Bressani, A. Adamo, R. Garfagnini, U. Gastaldi, E. Rossetto, Marco Bruschi, G. Maron, L. Vannucci, R. A. Ricci, F. Balestra, E. Lodi Rizzini, Armando Lanaro, A.M. Rozhdestvensky, M. Poli, G. Vedovato, Paola Gianotti, and L. Busso

Subjects
Nuclear physics, Physics, Particle physics, OZI rule, Production (computer science), Bar (unit)
Abstract

A preliminary study of\(\bar np\) three-prong annihilations into the channels K− K+ π+ and π− π+ π+ π0 is presented for ∼ 100–297 MeV/c\(\bar n\) momenta. The extracted φπ+/ωπ+ production ratio shows that also in this channel, never measured before using an\(\bar np\) beam, the OZI rule is strongly violated.

Published
1994

123. Evidence of a new state at ∼ 1660 MeV/c2 observed in $$\bar np$$ annihilationsannihilations

Author

C. De Leo, L. Venturelli, S. Costa, Paolo Montagna, G. Puddu, D. Yu. Denisov, S.N. Prakhov, L. Fava, G.C. Bonazzola, Paola Salvini, Mauro Villa, R. Spighi, Bruno Minetti, Alberto Masoni, Maurizio Piccinini, S. De Castro, M.G. Sapozhnikov, G. Belli, D. Calvo, N. Semprini Cesari, A. Saino, L. Santi, E. Rossetto, M. Corradini, F. Nichitiu, V.G. Ableev, Armando Lanaro, M. Capponi, A. Maggiora, A. Grasso, G. Pauli, Antonietta Donzella, B. Giacobbe, Tullio Bressani, V. Lucherini, U. Gastaldi, L. Busso, Michelangelo Agnello, M. Poli, G. Vedovato, P. Cerello, Petar Temnikov, A. Bertin, B. Cereda, G. L. Usai, D. Panzieri, S. Serci, M. Lombardi, Paola Gianotti, G. Maron, L. Vannucci, A. Adamo, A. Filippi, Antonio Zoccoli, V. Filippini, T. D. Galli, F. Balestra, A.M. Rozhdestvensky, Marco Bruschi, E. Lodi Rizzini, Aldo Zenoni, I. Massa, S. Marcello, Felice Iazzi, F. D'Isep, Corrado Cicalo, Gianfranco Zosi, Adriano Fontana, M.P. Bussa, Stefania Vecchi, F. Tosello, S. Tessaro, U. Marconi, A. Vitale, R. Garfagnini, Elena Botta, M. Morando, V.I. Tretyak, C. Guaraldo, G. Piragino, G. Bendiscioli, G. V. Margagliotti, Alessandro Feliciello, L. Ferrero, Alberto Rotondi, R. A. Ricci, and P. Boccaccio

Subjects
Physics, Nuclear physics, Annihilation, Bar (music), Spectrum (functional analysis), High Energy Physics::Experiment, Invariant mass, State (functional analysis), Atomic physics, Nuclear Experiment
Abstract

A study of\(\bar np\) in-flight annihilations is presented. The 4π invariant mass spectrum resulting from the analysis of the five-prong exclusive events, following the annihilation of ∼ (100–297) MeV/c\(\bar n\), reveals, besides a large structure centred at ∼ 1500 MeV/c2, some evidences for a new state around 1660 MeV/c2.

Published
1994

124. Measurement of the frequency of the annihilation reaction p → ππ at rest in a NTP hydrogen target

Author

L. Fava, C. Guaraldo, A.M. Rozhdestvensky, U. Marconi, Armando Lanaro, Bruno Minetti, A. Vitale, S. De Castro, A. Bertin, M. Capponi, Tullio Bressani, M. Poli, G. Vedovato, Paola Gianotti, Piergiorgio Cerello, L. Busso, Maurizio Piccinini, I. D'Antone, U. Gastaldi, S. Serci, Mauro Villa, R. Spighi, A. Saino, Michelangelo Agnello, R. Garfagnini, Antonietta Donzella, V. Filippini, A. Grasso, G. Maron, B. Giacobbe, P.P. Temnikov, Gianfranco Zosi, I. Massa, Alberto Masoni, S. Marcello, Aldo Zenoni, Adriano Fontana, A. Ferretti, D. Calvo, Marco Bruschi, D. Galli, A. Feliciello, F. Nichitiu, G. Pauli, Alberto Andrighetto, Paolo Montagna, A. Maggiora, V. Lucherini, B. Cereda, P. Boccaccio, Paola Salvini, A. Filippi, Elena Botta, M. Lombardi, G. Puddu, L. Venturelli, L. Ferrero, F. Balestra, M. G. Sapozhinikov, Alberto Rotondi, M.P. Bussa, S. Costa, Stefania Vecchi, Felice Iazzi, L. Vannucci, Corrado Cicalo, N. Semprini Cesari, L. Santi, G. L. Usai, F. Tosello, S. Tessaro, E. Lodi Rizzini, E. Rossetto, D. Panzieri, G. Bendiscioli, Antonio Zoccoli, V.I. Tretyak, and M. Morando

Subjects
Rest (physics), Physics, Nuclear physics, Nuclear and High Energy Physics, Angular momentum, Annihilation, Hydrogen, chemistry, Antiproton, chemistry.chemical_element, Atomic physics
Abstract

The annihilation frequency of the reaction p p → π 0 π 0 has been measured, for the first time by stopping antiprotons in a NTP hydrogen target. The obtained result ƒ(π 0 π 0 ) NTP = (12.7±0.5±2.0)×10 −4 is discussed in the frame of the study of the initial angular momentum of the pp system.

Published
1994

125. Measurement of the frequency of the annihilation reaction pp → π0π0 at rest in a NTP hydrogen target

Author

M. Agnello, A. Andrighetto, F. Balestra, G. Bendiscioli, A. Bertin, P. Boccaccio, E. Botta, T. Bressani, M. Bruschi, M.P. Bussa, L. Busso, D. Calvo, M. Capponi, B. Cereda, P. Cerello, C. Cicalò, S. Costa, I. D'Antone, S. De Castro, A. Donzella, L. Fava, A. Feliciello, L. Ferrero, A. Ferretti, A. Filippi, V. Filippini, A. Fontana, D. Galli, R. Garfagnini, U. Gastaldi, B. Giacobbe, P. Gianotti, A. Grasso, C. Guaraldo, F. Iazzi, A. Lanaro, E. Lodi Rizzini, M. Lombardi, V. Lucherini, A. Maggiora, S. Marcello, U. Marconi, G. Maron, A. Masoni, I. Massa, B. Minetti, P. Montagna, M. Morando, F. Nichitiu, D. Panzieri, G. Pauli, M. Piccinini, M. Poli, G. Puddu, E. Rossetto, A. Rotondi, A.M. Rozhdestvensky, A. Saino, P. Salvini, L. Santi, M.G. Sapozhinikov, N. Semprini Cesari, S. Serci, R. Spighi, P. Temnikov, S. Tessaro, F. Tosello, V.I. Tretyak, G. Usai, L. Vannucci, S. Vecchi, G. Vedovato, L. Venturelli, M. Villa, A. Vitale, A. Zenoni, A. Zoccoli, and G. Zosi

Subjects
lcsh:Physics, lcsh:QC1-999
Abstract

The annihilation frequency of the reaction pp → π0π0 has been measured, for the first time by stopping antiprotons in a NTP hydrogen target. The obtained result ƒ(π0π0)NTP = (12.7±0.5±2.0)×10−4 is discussed in the frame of the study of the initial angular momentum of the p̄p system.

Published
1994

126. Measurement of the annihilation frequencies in a 5 mb hydrogen gas target

Author

G. V. Margagliotti, M.P. Bussa, P. Boccaccio, Stefania Vecchi, A. Masoni, G. Bonazzola, A.M. Rozhdestvensky, S. Costa, S. De Castro, G. Pauli, A. Feliciello, Piergiorgio Cerello, R. A. Ricci, M. Capponi, Tullio Bressani, Sergio Serci, Michelangelo Agnello, I. D'Antone, C. Guaraldo, R. Garfagnini, L. Vannucci, U. Gastaldi, G. Piragino, D. Calvo, Antonietta Donzella, Maurizio Piccinini, G. Belli, M. Lombardi, D. Galli, A. Grasso, Petar Temnikov, A. Bertin, F. Tosello, S. Tessaro, F. Balestra, V.I. Tretyak, G. Maneva, L. Ferrero, N. Semprini Cesari, L. Santi, A. Lai, I. Massa, U. Marconi, M.G. Sapozhnikov, Felice Iazzi, A. Vitale, Alberto Andrighetto, Corrado Cicalo, L. Musa, Paola Salvini, A. Maggiora, S. Marcello, V. Lucherini, V.G. Ableev, Bruno Minetti, M. Morando, Mauro Villa, Alberto Rotondi, D. Panzieri, A. Filippi, G. Puddu, M. Poli, F. D'Isep, G. Vedovato, G. Bendiscioli, V. Filippini, E. Lodi Rizzini, L. Fava, R. Spighi, A. Adamo, Gianfranco Zosi, E. Rossetto, A. Zenoni, Marco Bruschi, G. L. Usai, G. Maron, L. Venturelli, M. Corradini, F. Nichitiu, Paola Gianotti, Armando Lanaro, Antonio Zoccoli, Paolo Montagna, and L. Busso

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Hydrogen, chemistry, Pi, chemistry.chemical_element, Atomic physics
Abstract

We report the first measurement of the K+K−, π+π− frequencies for p annihilations at rest in a gaseous H2 target at low pressure (5 mbar). We have obtained: fππ = (4.26±0.11)×10−3, fKK = (0.46±0.03)×10−3. The ratio R = fKK/fππ has also been measured at a pressure of 2 mbar. Comparison with previous measurements shows that fKK decreases monotonically with the target density but its value at 5 mbar is still higher than the value with L X-ray in coincidence.

Published
1994

127. Two-photon laser spectroscopy of antiprotonic helium and the antiproton-to-electron mass ratio

Author

D. Barna, B. Juhász, D Horváth, L. Venturelli, Andreas Dax, Ryugo S. Hayano, Eberhard Widmann, Anna Sótér, Masaki Hori, S. Friedreich, T. Pask, and N. Zurlo

Subjects
Atomic Physics (physics.atom-ph), FOS: Physical sciences, chemistry.chemical_element, Antiproton, Electron, Spectral line, Physics - Atomic Physics, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Exotic Atoms, Antiprotonic Helium, CPT symmetry, Laser Spectroscopy, Physics::Atomic Physics, Nuclear Experiment (nucl-ex), Spectroscopy, Nuclear Experiment, Antiprotonic helium, Helium, Exotic atom, Physics, Multidisciplinary, chemistry, Atomic physics, Doppler broadening
Abstract

Physical laws are believed to be invariant under the combined transformations of charge, parity and time reversal (CPT symmetry). This implies that an antimatter particle has exactly the same mass and absolute value of charge as its particle counterpart. Metastable antiprotonic helium ($\bar{p}{\rm He}^+$) is a three-body atom consisting of a normal helium nucleus, an electron in its ground state and an antiproton ($\bar{p}$) occupying a Rydberg state with high principal and angular momentum quantum numbers, respectively $n$ and $\ell$, such that $n\sim\ell\sim 38$. These atoms are amenable to precision laser spectroscopy, the results of which can in principle be used to determine the antiproton-to-electron mass ratio and to constrain the equality between the antiproton and proton charges and masses. Here we report two-photon spectroscopy of antiprotonic helium, in which $\bar{p}{\rm ^3He^+}$ and $\bar{p}{\rm ^4He^+}$ isotopes are irradiated by two counter-propagating laser beams. This excites nonlinear, two-photon transitions of the antiproton of the type $(n,\ell)\rightarrow (n-2,\ell-2)$ at deep-ultraviolet wavelengths ($\lambda$=139.8, 193.0 and 197.0nm), which partly cancel the Doppler broadening of the laser resonance caused by the thermal motion of the atoms. The resulting narrow spectral lines allowed us to measure three transition frequencies with fractional precisions of 2.3-5 parts in $10^9$. By comparing the results with three-body quantum electrodynamics calculations, we derived an antiproton-to-electron mass ratio of 1,836.1526736(23), where the parenthetical error represents one standard deviation. This agrees with the proton-to-electron value known to a similar precision.

Published
2011

128. Features of pi-induced collective resonances in nuclei A semi-empirical model for collective nuclear resonances in the Delta energy region

Author

T. Blokhintseva, Andrea Bianconi, R. Garfagnini, V.A. Drozdov, M. Artoni, I. Gnesi, A. Kirilov, M. Corradini, F. Tosello, G. Piragino, B. Parsamyan, I. A. Belolaptikov, G.B. Pontecorvo, M. L. Colantoni, A. Grasso, V. I. Lyashenko, A. Moiseenko, S. Baginyan, E. Lodi Rizzini, V.A. Panyushkin, V.V. Ivanov, Vladimir Frolov, D. Panzieri, Yu.A. Batusov, M. Chiosso, N. Russakovich, Gianfranco Zosi, A.M. Rozhdestvensky, Enrico Scalas, A. Dem’yanov, N. Angelov, V. Grebenyuk, P. Batyuk, F. Balestra, L. Venturelli, M. Schepkin, A. Maggiora, and V M Kovalenko

Subjects
Elastic scattering, Physics, Nuclear and High Energy Physics, PIONS, K+ COLLISIONS, Nuclear Theory, Hadron, Binding energy, XE NUCLEI, Nuclear structure, Nuclear matter, NARROW BARYON RESONANCE, TOTAL CROSS-SECTIONS, POSITIVE STRANGENESS, SCATTERING, HE-4, Excited state, Nuclear fusion, Atomic physics, Nuclear Experiment, Nucleon
Abstract

A semi-empirical model is presented for the excitation of collective nuclear resonances induced by pions on nuclei in the Δ(1232) energy region. The physical features of the collective states have been extracted according to the model by fitting data from a collection of resonant π-nucleus elastic scattering cross-sections. The contributions to the total binding energy and to the width of a collective state per each additional nucleon involved in the resonance have been extracted. The interaction between the collective resonances and the surrounding nuclear medium is discussed.

Published
2011

129. Pion induced reactions on4He in the Δ resonance energy region

Author

V. M. Grebenyuk, M. L. Colantoni, A.M. Rozhdestvensky, S. Baginyan, Michela Chiosso, F. Tosello, M. Corradini, A. Dem’yanov, E. Lodi Rizzini, Yu.A. Batusov, I. A. Belolaptikov, N.S. Angelov, T. Blokhintseva, V.E. Kovalenko, V.A. Drozdov, M. Artoni, V.A. Panyushkin, A. Moiseenko, D. Panzieri, G. Piragino, Ivan Gnesi, B. Parsamyan, P. Batyuk, G.B. Pontecorvo, Gianfranco Zosi, F. Balestra, R. Garfagnini, A. Grasso, A. Kirilov, M. Schepkin, Enrico Scalas, Andrea Bianconi, V. I. Lyashenko, A. Maggiora, L. Venturelli, N.A. Russakovich, V.V. Ivanov, and Vladimir Frolov

Subjects
Physics, Nuclear reaction, History, PAINUC experiment, Meson, PACS 27.10.+h, Resonance, PACS 25.80.-e, Delta resonance, PACS 21.65.-f, PACS 21.10.Re, pion nucleus interactions, charged pion He-4 interactions, collective resonance, Nuclear matter, Computer Science Applications, Education, Delta baryon, Nuclear physics, Pion, Atomic physics, Isotopes of helium, Excitation
Abstract

Measurement of the in-medium modifications of the Δ resonance, signatures of the excitation of nuclear collective states and the first experimental evidence for a thermal emission of photons have been obtained from the analysis of new π±4He data at Tπ = 106 MeV at PAINUC experiment.

Published
2011

130. PION INDUCED REACTIONS ON (4)He IN THE Delta RESONANCE ENERGY REGION

Author

I. A. Belolaptikov, I. Gnesi, F. Tosello, Ivanov, P. Batyuk, F. Balestra, Frolov, Drozdov, L. Venturelli, G. Piragino, S. Baginyan, Panyushkin, M. Schepkin, A. Moiseenko, Kovalenko, Gianfranco Zosi, M. Artoni, R. Garfagnini, A. Grasso, D Panziera, A. Kirilov, M. Chiosso, M. Corradini, A. Maggiora, Andrea Bianconi, Grebenyuk, N. Russakovich, Yu Batusiv, A.M. Rozhdestvensky, A. Dem’yanov, N. Angelov, Lyashenko, T. Blokhintseva, Enrico Scalas, B. Parsamyan, G.B. Pontecorvo, E L Rizzini, and M. L. Colantoni

Subjects
Physics, Nuclear and High Energy Physics, Phase transition, PAINUC experiment, Photon, pion resonances, nuclear physics, Collective state, Astronomy and Astrophysics, Nuclear matter, Resonance (particle physics), Atomic and Molecular Physics, and Optics, Nuclear physics, Pion, phase transition, nuclear matter, Collective resonance, Atomic physics, Excitation, Energy (signal processing)
Abstract

The analysis of new data on π±4 He interaction at T π =106 MeV provided information on the in-medium modifications of the Δ resonance and revealed signatures of the excitation of a nuclear collective state. Evidences for a reaction channel with thermal emission of photons are also presented.

Published
2011

131. stopping power in hydrogen below 1 MeV and the 4He metastable state

Author

S. Costa, Antonietta Donzella, G. V. Margagliotti, A. Feliciello, L. Ferrero, M. Poli, G. Vedovato, U. Marconi, Alberto Rotondi, G. Maron, Antonio Zoccoli, M. Capponi, G. Bonazzola, Tullio Bressani, D. Galli, A.M. Rozhdestvensky, Paola Salvini, G. Bendiscioli, U. Gastaldi, Sergio Serci, Michelangelo Agnello, L. Fava, L. Venturelli, M.P. Bussa, V.I. Tretyak, F. Nichitiu, G. Piragino, F. Tosello, A. Vitale, Stefania Vecchi, P. Boccaccio, Mauro Villa, Maurizio Piccinini, V. Filippini, Armando Lanaro, C. Guaraldo, M. Morando, R. Garfagnini, A. Maggiora, E. Zavattini, M. Corradini, L. Busso, S. Tessaro, G. Puddu, A. Masoni, P. Gianotti, P.P. Temnikov, Gianfranco Zosi, V. Lucherini, G. L. Usai, Bruno Minetti, L. Vannucci, F. Balestra, A. Adamo, I. Massa, E. Rossetto, M. Panzieri, M. Lombardi, S. Marcello, Felice Iazzi, C. Rizzo, G. Pauli, Corrado Cicalo, A. Zenom, Marco Bruschi, F. D'Isep, S. De Castro, N. Semprini Cesari, R. A. Ricci, Paolo Montagna, D. Calvo, M.G. Sapozhmkov, G. Belli, E. Lodi Rizzini, L. Santi, A. Grasso, and A. Bertin

Subjects
Physics, Nuclear and High Energy Physics, chemistry, Hydrogen, Gas pressure, Spectrometer, Metastability, Energy interval, Low density, chemistry.chemical_element, Stopping power, Atomic physics, Helium
Abstract

The stopping power of H, for p S was measured in the p energy interval 1 keV + 120 keV using a low density gas target ( p pρ ≈ l0 −3 + 10 −2 ÷ pρ being the Hz density at STP) with the OBELIX spectrometer at the LEAR of CEBN. Furthermore, the formation of metastable states in the p 4 He interaction at rest, having a mean life of the order of 3 μs, was investigated at six target gas pressures (3 atm and 400,250,200,150,50 mbar). The influence of contaminants (like Ha, Ne, Ar, N2 and Xe) on the life of such metastable states was examined at the target gas pressure of 3 atm.

Published
1993

132. Synthesis of cold antihydrogen in a cusp trap

Author

Hiroyuki Higaki, B. Juhász, H. Imao, Y. Enomoto, Hiroyuki A. Torii, L. Venturelli, C. Kim, M. Ohtsuka, Naofumi Kuroda, Nicola Zurlo, K. Michishio, M. Leali, E. Lodi-Rizzini, Yasuyuki Nagashima, M. Corradini, Yasunori Yamazaki, Valerio Mascagna, Y. Nagata, A. Mohri, K. S. Tanaka, Yasuyuki Kanai, Yasuyuki Matsuda, and K. Fujii

Subjects
Condensed Matter::Quantum Gases, Physics, Physics::General Physics, CPT symmetry, General Physics and Astronomy, Antiprotons, Antiproton Decelerator, Physics and Astronomy (all), Positrons, Antiproton, Atom, Antihydrogen, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Rotational spectroscopy, Atomic physics, Spectroscopy, Hyperfine structure
Abstract

We report here the first successful synthesis of cold antihydrogen atoms employing a cusp trap, which consists of a superconducting anti-Helmholtz coil and a stack of multiple ring electrodes. This success opens a new path to make a stringent test of the CPT symmetry via high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atoms.

Published
2010

133. Hypernuclear physics at DAφNE, the frascati φ-factory

Author

P. Gianotti, F. D'Isep, Tullio Bressani, Alessandro Feliciello, S. Costa, Daniela Calvo, C. Guaraldo, Michelangelo Agnello, E. Lodi Rizzini, Felice Iazzi, S. Marcello, G.C. Bonazzola, L. Venturelli, V. Lucherini, A. Lanaro, Bruno Minetti, and E. Rossetto

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Spectrometer, Field (physics), Detector, Factory (object-oriented programming), High resolution
Abstract

The low-energy, background free and tagged K−s from the φ(1020) decay produced at the DAφNE φ-factory in Frascati offer a unique opportunity for high resolution hypernuclei spectroscopy with K−at rest. In this paper we outline the general problematics of this interesting field, expose the physics motivations that support our proposal and, finally, describe the techniques foreseen for precise measurements of the hypernuclear level energies and their decay modes. In this regard we investigated the performances of a magnetic spectrometer foreseen for] one of the interaction region of the DAφNE machine. Details on the detector characteristics as well as on its response to all the particles in the final state will be extensively discussed.

Published
1992

134. [Doping and sport: SIP-UISP-ISS experience]

Author

A, Ferrando, M, Costabile, E, Napoleone, S, Bertelloni, A, Fischer, S, Pontone Gravaldi, N, D'amario, F, Leonardi, L, Venturelli, F, Sferrazzo, C, Colucci, A, Ballestrazzi, F, Giuntini, A, Calzolari, L, Argiolas, M, Baltieri, P, Pancheri, L, Loschi, B, Ruffato, F, Pastore, E, Caggiano, and A, Correra

Subjects
Doping in Sports, Adolescent, Italy, Humans, Pediatrics
Published
2009

138. Antihydrogen (hydrogen) atom formation

Author

Nicola Zurlo, E. Lodi Rizzini, and L. Venturelli

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Hydrogen atom, Physical and Theoretical Chemistry, Atomic physics, Condensed Matter Physics, Antihydrogen, Atomic and Molecular Physics, and Optics, Bar (unit)
Abstract

In this paper we show how the ATHENA data samples on the antihydrogen ( ${\bar{\rm H}}$ ) formation in very different conditions provide useful information on the two different possible mechanisms: the 3-body reaction ( $\bar{p}+{e^+}+{e^+}\rightarrow {\bar{\rm H}}+ e^+$ ) and the 2-body reaction ( $\bar{p}+{\rm e^+}\rightarrow {\bar{\rm H}}+{h\nu}$ ).

Published
2009

139. Measurement of the antiproton-nucleus annihilation cross-section at very low energies

Author

Valerio Mascagna, E. Lodi Rizzini, Masaki Hori, A. Mozzanica, M. Corradini, E. Vallazza, M. Leali, M. Prest, Nicola Zurlo, and L. Venturelli

Subjects
Antiparticle, Particle physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Annihilation, Antiproton, Nuclear physics, Atomic and Molecular Physics, Nuclear, Physics::Atomic Physics, Physical and Theoretical Chemistry, Antihydrogen, Nuclear Experiment, Antiprotonic helium, Physics, Cross section, Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Antiproton Decelerator, Antimatter, Physics::Accelerator Physics, High Energy Physics::Experiment, and Optics, Nucleon
Abstract

The main fields of investigation of the ASACUSA Experiment at the Antiproton Decelerator at CERN concern test of CPT violation through spectroscopy of antihydrogen and antiprotonic helium, atomic collision and nuclear physics experiments. The nuclear physics program foresees measurements of p-nuclei cross sections at low energies (from few MeV down to the keV region) using a cylindrical detector with 6 layers of scintillating fibers surrounding the target. These measurements will contribute to understand the dynamic of the annihilation process and in particular to explain why the antiproton-nucleus annihilation rate at very low energy appears independent from the size of the target, as measured by the Obelix Collaboration at CERN for H, D and He. The preliminary results of the measurements performed during 2008 are presented.

Published
2009

140. FINUDA, the physics program

Author

V. Filippini, M. Agnello, P.A. Amaudruz, G. Beer, L. Benussi, M. Bertani, S. Bianco, E. Botta, T. Bressani, L. Busso, D. Calvo, P. Camerini, L. Celano, P. Cerello, G. D'Erasmo, F.L. Fabbri, A. Feliciello, A. Filippi, E.M. Fiore, L. Fiore, P. Gianotti, M. Giardoni, D.R. Gill, N. Grion, C. Guaraldo, L. Jie, F. Iazzi, A. Lanaro, L. Lee, V. Lucherini, S. Marcello, G. Marciano, B. Minetti, N. Mirfakhrai, O. Morra, A.A. Nozdrin, A. Olin, E. Pace, A. Pantaleo, V. Paticchio, A. Raimondo, E. Rossetto, A. Rotondi, R. Ruih, P. Salvini, S. Sarwar, V. Serdyuk, G. Smith, L. Trasatti, L. Venturelli, R. Wheadon, S. Yen, A. Zenoni, A. Zia, V., Filippini, M., Agnello, P. A., Amaudruz, G., Beer, L., Benussi, M., Bertani, S., Bianco, E., Botta, T., Bressani, L., Busso, D., Calvo, Camerini, Paolo, L., Celano, P., Cerello, G., D'Erasmo, F. L., Fabbri, A., Feliciello, A., Filippi, E. M., Fiore, L., Fiore, P., Gianotti, M., Giardoni, D. R., Gill, N., Grion, C., Guaraldo, L., Jie, F., Iazzi, A., Lanaro, L., Lee, V., Lucherini, S., Marcello, G., Marciano, B., Minetti, N., Mirfakhrai, O., Morra, A. A., Nozdrin, A., Olin, E., Pace, A., Pantaleo, V., Paticchio, A., Raimondo, E., Rossetto, A., Rotondi, Rui, Rinaldo, P., Salvini, S., Sarwar, V., Serdyuk, G., Smith, L., Trasatti, L., Venturelli, R., Wheadon, S., Yen, A., Zenoni, and A., Zia

Subjects
Nuclear physics, Physics, Nuclear reaction, Nuclear and High Energy Physics, Pion, Meson, Hadron, Monte Carlo method, Elementary particle, kaons, Particle detector, Background radiation
Published
1998

141. Temporally Controlled Modulation of Antihydrogen Production and the Temperature Scaling of Antiproton-Positron Recombination

Author

Adriano Fontana, P. Genova, Paolo Montagna, V. Lagomarsino, Claude Amsler, L. V. Jørgensen, M. Charlton, Ryugo S. Hayano, L. Venturelli, C. L. Cesar, D. P. van der Werf, G. Manuzio, E. Lodi-Rizzini, C. Regenfus, R. Landua, D. Mitchard, Germano Bonomi, C. Carraro, Niels Madsen, Alberto Rotondi, Alessandro Variola, Alban Kellerbauer, J. S. Hangst, M. C. Fujiwara, Yasunori Yamazaki, M. Amoretti, R. Funakoshi, Adam Bouchta, Nicola Zurlo, Carlo Canali, M. Macri, H.S. Pruys, P. D. Bowe, G. Testera, and Michael Doser

Subjects
Physics, General Physics and Astronomy, Pulse duration, Plasma, Penning trap, Accelerators and Storage Rings, Nuclear physics, Positron, Antiproton, Antimatter, Physics::Accelerator Physics, Plasma diagnostics, Physics::Atomic Physics, Atomic physics, Antihydrogen
Abstract

We demonstrate temporally controlled modulation of cold antihydrogen production by periodic RF heating of a positron plasma during antiproton-positron mixing in a Penning trap. Our observations have established a pulsed source of atomic antimatter, with a rise time of about 1 s, and a pulse length ranging from 3 to 100 s. Time-sensitive antihydrogen detection and positron plasma diagnostics, both capabilities of the ATHENA apparatus, allowed detailed studies of the pulsing behavior, which in turn gave information on the dependence of the antihydrogen production process on the positron temperature T. Our data are consistent with power law scaling T (-1.1+/-0.5) for the production rate in the high temperature regime from approximately 100 meV up to 1.5 eV. This is not in accord with the behavior accepted for conventional three-body recombination.

Published
2008

144. PRODUCTION AND STUDY OF ANTIHYDROGEN IN THE ATHENA EXPERIMENT

Author

G. Manuzio, E. Lodi Rizzinia, R. Landua, N. Zurlo, M. Macri, C. L. Cesar, D. Mitchard, P. Montagna, Alban Kellerbauer, M. Amoretti, H. Pruys, P. Genova, L. Venturelli, M. Charlton, G. Testera, Alberto Rotondi, C. Carraro, Carlo Canali, Alessandro Variola, M. C. Fujiwara, Adriano Fontana, J. S. Hangst, L. V. Jørgensen, D. P. van der Werf, R. Funakoshi, P. D. Bowe, Ryugo S. Hayano, Michael Doser, Niels Madsen, Claude Amsler, Germano Bonomi, Yasunori Yamazaki, V. Lagomarsino, and C. Regenfus

Subjects
Nuclear physics, Physics, Antiproton Decelerator, Large Hadron Collider, Antihydrogen
Abstract

In the last three years of data taking, the ATHENA experiment at the CERN Antiproton Decelerator facility has been able to produce large amounts of antihydrogen atoms and to study the formation process in detail. Moreover, in 2004, ATHENA tried to produce antihydrogen by means of laser stimulation. In this contribution we summarize the main results obtained and the progress made in analysing the results of the laser experiment.

Published
2007

145. ASACUSA STATUS REPORT ASACUSA progress during 2006 and plans for 2007 ASACUSA collaboration

Author

H H Andersen, D Barna, M Charlton, M Corradini, A Dax, J Eades, Y Enomoto, R S Hayano, H Higaki, M Hori, D Horváth, T Ichioka, H Imao, B Juhász, Y Kanai, H Knudsen, P Kristiansen, N Kuroda, M Leali, E Lodi-Rizzini, C Malbrunot, B Mccollough, S P Møller, A Mohri, A Mozzanica, Y Nagata, N Ono, T Pask, W Pirkl, A Puhm, H Saito, K Tokesi, H A Torii, U Uggerhøj, V L Varentsov, L Venturelli, E Widmann, Y Yamazaki, Z Yoshida, P Zalan, and N Zurlo

Published
2007
Full Text
View/download PDF

146. Protonium production in ATHENA

Author

P. Genova, E. Lodi Rizzini, H.S. Pruys, V. Lagomarsino, C. Regenfus, Nicola Zurlo, Niels Madsen, C. Carraro, M. Charlton, G. Manuzio, G. Testera, L. G. C. Posada, R. Funakoshi, Michael Doser, C. L. Cesar, L. V. Jørgensen, M. Amoretti, Ryugo S. Hayano, Germano Bonomi, Alessandro Variola, M. Macri, D. P. van der Werf, R. Landua, D. Mitchard, P. Montagna, Claude Amsler, L. Venturelli, Alban Kellerbauer, Yasunori Yamazaki, Alberto Rotondi, and Adriano Fontana

Subjects
Physics, Nuclear and High Energy Physics, Antiparticle, Dihydrogen cation, Penning trap, Nuclear physics, Protonium, Antiproton, Antimatter, Atom, Physics::Accelerator Physics, Physics::Atomic Physics, Atomic physics, Nuclear Experiment, Antihydrogen, Instrumentation
Abstract

The ATHENA experiment at CERN, after producing cold antihydrogen atoms for the first time in 2002, has synthesised protonium atoms in vacuum at very low energies. Protonium, i.e. the antiproton–proton bound system, is of interest for testing fundamental physical theories. In the nested penning trap of the ATHENA apparatus protonium has been produced as result of a chemical reaction between an antiproton and the simplest matter molecule, H 2 + . The formed protonium atoms have kinetic energies in the range 40–700 meV and are metastable with mean lifetimes of the order of 1 μs. Our result shows that it will be possible to start measurements on protonium at low energy antiproton facilities, such as the AD at CERN or FLAIR at GSI.

Published
2007

147. On the chemical reaction of matter with antimatter

Author

L. Venturelli, Evandro Lodi Rizzini, and N. Zurlo

Subjects
Physics, Hydrogen atom, Penning trap, Atomic and Molecular Physics, and Optics, Ion, Antiproton, Protonium, Antimatter, Excited state, Elementary reaction, Physics::Atomic Physics, Physical and Theoretical Chemistry, Atomic physics, Nuclear Experiment
Abstract

A chemical reaction between the building block antiatomic nucleus, the antiproton (p or H- in chemical notation), and the hydrogen molecular ion (H2+) has been observed by the ATHENA collaboration at CERN. The charged pair interact via the long-range Coulomb force in the environment of a Penning trap which is purpose-built to observe antiproton interactions. The net result of the very low energy collision of the pair is the creation of an antiproton-proton bound state, known as protonium (Pn), together with the liberation of a hydrogen atom. The Pn is formed in a highly excited, metastable, state with a lifetime against annihilation of around 1 micros. Effects are observed related to the temperature of the H2+ prior to the interaction, and this is discussed herein.

Published
2007

148. FAST: A scintillating fiber tracker for antiprotons annihilation detection

Author

Davide Bolognini, L. Venturelli, Nicola Zurlo, A. Mozzanica, M. Corradini, E. Vallazza, M. Prest, M. Leali, and E. Lodi Rizzini

Subjects
Very-large-scale integration, Physics, Nuclear and High Energy Physics, Scintillation, Annihilation, Large Hadron Collider, Physics::Instrumentation and Detectors, Detector, Antiproton annihilation cross section, Nuclear physics, Antiproton Decelerator, Antiproton, Fiber, scintillating fibers, tracker, Instrumentation
Abstract

A new fiber detector has been developed for the measurement of the annihilation cross-section of slow antiprotons (5 MeV for the 2006 run, 1 keV in 2007) in gaseous targets in the framework of the ASACUSA experiment at the AD Antiproton Decelerator at CERN. The cylindrical gaseous target, 10 cm in radius, is surrounded by 2 axial and 4 stereo scintillating fiber layers built with 1 mm BCF-10 fibers from Bicron. The scintillation light released by charged pions originating in the annihilation vertex is readout by 64 channel multianode PMTs produced by HAMAMATSU. The anode outputs are amplified and discriminated with VLSI ASICs manufactured by IDEAS (VA64TAP2.1) and then sampled with a 320 MHz clock in order to extract the hit and time information by a set of ALTERA FPGAs. The paper describes the detector assembly, the custom electronics readout chain and the results of the tests during the commissioning phase.

Published
2007

149. Positron plasma control techniques for the production of cold antihydrogen

Author

Alessandro Variola, J. S. Hangst, Yasunori Yamazaki, G. Manuzio, D. Mitchard, P. Montagna, Ryugo S. Hayano, L. G. C. Posada, Carlo Canali, L. Venturelli, Alban Kellerbauer, M. Amoretti, M. Macri, D. P. van der Werf, Niels Madsen, L. V. Jørgensen, P. Genova, R. Landua, P. D. Bowe, Adriano Fontana, Nicola Zurlo, V. Lagomarsino, M. Charlton, C. L. Cesar, C. Carraro, M. C. Fujiwara, R. Funakoshi, Germano Bonomi, E. Lodi Rizzini, G. Testera, Michael Doser, and Alberto Rotondi

Subjects
Physics, Range (particle radiation), Hydrogen, chemistry.chemical_element, Plasma, Atomic and Molecular Physics, and Optics, Ion, Positron, chemistry, Production (computer science), Plasma diagnostics, Atomic physics, Antihydrogen, Particle Physics - Experiment
Abstract

An observation of a clear dependence of antihydrogen production on positron plasma shapes is reported. For this purpose a plasma control method has been developed combining the plasma rotating-wall technique with a mode diagnostic system. With the help of real-time and nondestructive observations, the rotating-wall parameters have been optimized. The positron plasma can be manipulated into a wide range of shapes (aspect ratio 6.5{

Published
2007

150. New data on OZI rule violation in annihilation at rest

Author

Mauro Villa, A. Feliciello, Tullio Bressani, L. Fava, Felice Iazzi, A. Vezzani, O.Yu. Denisov, S. Marcello, D. D'Isep, A. Saino, U. Gastaldi, A.M. Rozhdestvensky, Maurizio Piccinini, S. De Castro, Corrado Cicalo, A. Grasso, Alberto Andrighetto, V.I. Tretyak, Michelangelo Agnello, A. Maggiora, Bruno Minetti, C. Guaraldo, V. Lucherini, R. Garfagnini, M.P. Bussa, S. Serci, A. Filippi, Paolo Montagna, Stefania Vecchi, D. Galli, L. Venturelli, Nicola Semprini-Cesari, F. Vigotti, E. Lodi Rizzini, Antonietta Donzella, Alberto Masoni, S. Costa, Gianfranco Zosi, Elena Botta, B. Giacobbe, D. Calvo, L. Busso, D. Panzieri, Adriano Fontana, G. Bendiscioli, G. Puddu, Paola Gianotti, A. Ferretti, Marco Bruschi, Paola Salvini, F. Tosello, G. L. Usai, V. Filippini, F. Balestra, S. Tessaro, G. V. Margagliotti, C. Cavion, E. Rossetto, L. Santi, Aldo Zenoni, Armando Lanaro, Petar Temnikov, A. Bertin, G. Belli, M. Morando, L. Ferrero, Alberto Rotondi, C. Petrascu, V.P. Nomokonov, D. Parena, U. Marconi, M. Lombardi, M.G. Sapozhnikov, V.G. Ableev, A. Vitale, R. Spighi, O.E. Gorchakov, A M Rosca, S.N. Prakhov, M. Corradini, F. Nichitiu, G. Pauli, Piergiorgio Cerello, M. Poli, Antonio Zoccoli, A., Bertin, M., Bruschi, S., De Castro, A., Ferretti, D., Galli, B., Giacobbe, U., Marconi, M., Poli, M., Piccinini, N., Semprini Cesari, R., Spighi, S., Vecchi, A., Vezzani, F., Vigotti, M., Villa, A., Vitale, A., Zoccoli, G., Belli, M., Corradini, A., Donzella, E., Lodi Rizzini, L., Venturelli, A., Zenoni, C., Cicaló, A., Masoni, G., Puddu, S., Serci, P. P., Temnikov, G., Usai, O., Yu Denisov, O. E., Gorchakov, V. P., Nomokonov, S. N., Prakhov, A. M., Rozhdestvensky, M. G., Sapozhnikov, V. I., Tretyak, P., Gianotti, C., Guaraldo, A., Lanaro, V., Lucherini, F., Nichitiu, C., Petrascu, A., Rosca, V. G., Ableev, C., Cavion, U., Gastaldi, M., Lombardi, A., Andrighetto, M., Morando, G., Bendiscioli, V., Filippini, A., Fontana, P., Montagna, A., Rotondi, A., Saino, P., Salvini, F., Balestra, E., Botta, T., Bressani, M. P., Bussa, L., Busso, D., Calvo, P., Cerello, S., Costa, L., Fava, A., Feliciello, L., Ferrero, A., Filippi, R., Garfagnini, A., Grasso, D., D'Isep, A., Maggiora, S., Marcello, D., Panzieri, D., Parena, E., Rossetto, F., Tosello, G., Zosi, M., Agnello, F., Iazzi, B., Minetti, Margagliotti, Giacomo, G., Pauli, Tessaro, Susanna, and L., Santi

Subjects
Physics, Rest (physics), Nuclear physics, Nuclear and High Energy Physics, Particle physics, PHI-MESON PRODUCTION, ANTIPROTON ANNIHILATION, Annihilation, OZI rule, Antiproton, Momentum transfer
Abstract

The results of measuring the ratio R = Y(φπ + π − ) Y(ωπ + π − ) for antiproton annihilation at rest in a gaseous and a liquid hydrogen target are presented. It was found that the value of this ratio increases with the decrease of the dipion mass, which demonstrates the difference between the φ and ω production mechanisms. An indication of the momentum transfer dependence of the apparent OZI rule violation for the φ production from the 3S1 initial state was found.

Published
1996

Catalog

Books, media, physical & digital resources
See catalog results