6 results on '"Rappazzo, G. F."'
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2. First Measurement of a Long-Lived π^{+}π^{-} Atom Lifetime.
- Author
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Adeva B, Afanasyev L, Anania A, Aogaki S, Benelli A, Brekhovskikh V, Cechak T, Chiba M, Chliapnikov PV, Doskarova P, Drijard D, Dudarev A, Dumitriu D, Fluerasu D, Gorin A, Gorchakov O, Gritsay K, Guaraldo C, Gugiu M, Hansroul M, Hons Z, Horikawa S, Iwashita Y, Karpukhin V, Kluson J, Kobayashi M, Kruglov V, Kruglova L, Kulikov A, Kulish E, Lamberto A, Lanaro A, Lednicky R, Mariñas C, Martincik J, Nemenov L, Nikitin M, Okada K, Olchevskii V, Ovsiannikov V, Pentia M, Penzo A, Plo M, Prusa P, Rappazzo GF, Romero Vidal A, Ryazantsev A, Rykalin V, Saborido J, Schacher J, Sidorov A, Smolik J, Takeutchi F, Trojek T, Trusov S, Urban T, Vrba T, Yazkov V, Yoshimura Y, and Zrelov P
- Abstract
The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike π^{+}π^{-} atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1 μm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n_{A}^{L}=436_{-61}^{+157}|_{tot}, the lifetime of the 2p state is found to be τ_{2p}=(0.45_{-0.30}^{+1.08}|_{tot})×10^{-11} s, not contradicting the corresponding QED 2p state lifetime τ_{2p}^{QED}=1.17×10^{-11} s. This lifetime value is three orders of magnitude larger than our previously measured value of the π^{+}π^{-} atom ground state lifetime τ=(3.15_{-0.26}^{+0.28}|_{tot})×10^{-15} s. Further studies of long-lived π^{+}π^{-} atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor ππ scattering lengths with the aim to check QCD predictions.
- Published
- 2019
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3. Observation of a narrow charm-strange meson D(+)(sJ)(2632)-->D(+)(s)eta and D(0)K(+).
- Author
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Evdokimov AV, Akgun U, Alkhazov G, Amaro-Reyes J, Atamantchouk AG, Ayan AS, Balatz MY, Bondar NF, Cooper PS, Dauwe LJ, Davidenko GV, Dersch U, Dolgolenko AG, Dzyubenko GB, Edelstein R, Emediato L, Endler AM, Engelfried J, Eschrich I, Escobar CO, Filimonov IS, Garcia FG, Gaspero M, Giller I, Golovtsov VL, Gouffon P, Gülmez E, Kangling H, Iori M, Jun SY, Kaya M, Kilmer J, Kim VT, Kochenda LM, Konorov I, Kozhevnikov AP, Krivshich AG, Krüger H, Kubantsev MA, Kubarovsky VP, Kulyavtsev AI, Kuropatkin NP, Kurshetsov VF, Kushnirenko A, Kwan S, Lach J, Lamberto A, Landsberg LG, Larin I, Leikin EM, Yunshan L, Luksys M, Lungov T, Maleev VP, Mao D, Chensheng M, Zhenlin M, Mathew P, Mattson M, Matveev V, McCliment E, Moinester MA, Molchanov VV, Morelos A, Nelson KD, Nemitkin AV, Neoustroev PV, Newsom C, Nilov AP, Nurushev SB, Ocherashvili A, Onel Y, Ozel E, Ozkorucuklu S, Penzo A, Petrenko SV, Pogodin P, Procario M, Ramberg E, Rappazzo GF, Razmyslovich BV, Rud VI, Russ J, Schiavon P, Simon J, Sitnikov AI, Skow D, Smith VJ, Srivastava M, Steiner V, Stepanov V, Stutte L, Svoiski M, Terentyev NK, Thomas GP, Torres I, Uvarov LN, Vasiliev AN, Vavilov DV, Vázquez-Jáuregui E, Verebryusov VS, Victorov VA, Vishnyakov VE, Vorobyov AA, Vorwalter K, You J, Wenheng Z, Shuchen Z, and Zukanovich-Funchal R
- Abstract
We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, D(+)(s)eta and D0K+. In the D(+)(s)eta decay mode we observe a peak with 101 events over a combinatoric background of 54.9 events at a mass of 2635.4+/-3.3 MeV/c(2). There is a corresponding peak of 21 events over a background of 6.9 at 2631.5+/-2.0 MeV/c(2) in the decay mode D0K+. The decay width of this state is <17 MeV/c(2) at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(D(+)(s)eta) is 0.14+/-0.06. The mechanism that keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the D(+)(s)eta decay mode.
- Published
- 2004
- Full Text
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4. First observation of the doubly charmed baryon Xi(+)(cc).
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Mattson M, Alkhazov G, Atamantchouk AG, Balatz MY, Bondar NF, Cooper PS, Dauwe LJ, Davidenko GV, Dersch U, Dolgolenko AG, Dzyubenko GB, Edelstein R, Emediato L, Endler AM, Engelfried J, Eschrich I, Escobar CO, Evdokimov AV, Filimonov IS, Garcia FG, Gaspero M, Giller I, Golovtsov VL, Gouffon P, Gülmez E, Kangling H, Iori M, Jun SY, Kaya M, Kilmer J, Kim VT, Kochenda LM, Konorov I, Kozhevnikov AP, Krivshich AG, Krüger H, Kubantsev MA, Kubarovsky VP, Kulyavtsev AI, Kuropatkin NP, Kurshetsov VF, Kushnirenko A, Kwan S, Lach J, Lamberto A, Landsberg LG, Larin I, Leikin EM, Yunshan L, Luksys M, Lungov T, Maleev VP, Mao D, Chensheng M, Zhenlin M, Mathew P, Matveev V, McCliment E, Moinester MA, Molchanov VV, Morelos A, Nelson KD, Nemitkin AV, Neoustroev PV, Newsom C, Nilov AP, Nurushev SB, Ocherashvili A, Oliveira E, Onel Y, Ozel E, Ozkorucuklu S, Penzo A, Petrenko SV, Pogodin P, Procario M, Prutskoi VA, Ramberg E, Rappazzo GF, Razmyslovich BV, Rud VI, Russ J, Schiavon P, Simon J, Sitnikov AI, Skow D, Smith VJ, Srivastava M, Steiner V, Stepanov V, Stutte L, Svoiski M, Terentyev NK, Thomas GP, Uvarov LN, Vasiliev AN, Vavilov DV, Verebryusov VS, Victorov VA, Vishnyakov VE, Vorobyov AA, Vorwalter K, You J, Wenheng Z, Shuchen Z, and Zukanovich-Funchal R
- Abstract
We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence.
- Published
- 2002
- Full Text
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5. Precision measurements of the lambda(+)(c) and D0 lifetimes.
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Kushnirenko A, Alkhazov G, Atamantchouk AG, Balatz MY, Bondar NF, Cooper PS, Dauwe LJ, Davidenko GV, Dersch U, Dolgolenko AG, Dzyubenko GB, Edelstein R, Emediato L, Endler AM, Engelfried J, Eschrich I, Escobar CO, Evdokimov AV, Filimonov IS, Garcia FG, Gaspero M, Giller I, Golovtsov VL, Gouffon P, Gülmez E, Kangling H, Iori M, Jun SY, Kaya M, Kilmer J, Kim VT, Kochenda LM, Konorov I, Kozhevnikov AP, Krivshich AG, Krüger H, Kubantsev MA, Kubarovsky VP, Kulyavtsev AI, Kuropatkin NP, Kurshetsov VF, Kwan S, Lach J, Lamberto A, Landsberg LG, Larin I, Leikin EM, Yunshan L, Luksys M, Lungov T, Maleev VP, Mao D, Chensheng M, Zhenlin M, Mathew P, Mattson M, Matveev V, McCliment E, Moinester MA, Molchanov VV, Morelos A, Nelson KD, Nemitkin AV, Neoustroev PV, Newsom C, Nilov AP, Nurushev SB, Ocherashvili A, Onel Y, Ozel E, Ozkorucuklu S, Penzo A, Petrenko SV, Pogodin P, Procario M, Prutskoi VA, Ramberg E, Rappazzo GF, Razmyslovich BV, Rud VI, Russ J, Schiavon P, Simon J, Sitnikov AI, Skow D, Smith VJ, Srivastava M, Steiner V, Stepanov V, Stutte L, Svoiski M, Terentyev NK, Thomas GP, Uvarov LN, Vasiliev AN, Vavilov DV, Verebryusov VS, Victorov VA, Vishnyakov VE, Vorobyov AA, Vorwalter K, You J, Wenheng Z, Shuchen Z, and Zukanovich-Funchal R
- Abstract
We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we observe lifetimes of tau[Lambda(+)(c)] = 198.1+/-7.0+/-5.6 fs and tau[D0] = 407.9+/-6.0+/-4.3 fs.
- Published
- 2001
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6. Observation of the Cabibbo-Suppressed Decay Ξ_{c}^{+} → pK^{-}π^{+}.
- Author
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Jun SY, Akchurin N, Andreev VA, Atamantchouk AG, Aykac M, Balatz MY, Bondar NF, Bravar A, Cooper PS, Dauwe LJ, Davidenko GV, Dersch U, Dolgolenko AG, Dreossi D, Dzyubenko GB, Edelstein R, Emediato L, Endler AM, Engelfried J, Eschrich I, Escobar CO, Evdokimov AV, Filimonov IS, Garcia FG, Gaspero M, Gerzon S, Giller I, Golovtsov VL, Goncharenko YM, Gottschalk E, Gouffon P, Grachov OA, Gülmez E, Iori M, Kamenski AD, Kangling H, Kaya M, Kilmer J, Kim VT, Kochenda LM, Königsmann K, Konorov I, Kozhevnikov AA, Krivshich AG, Krüger H, Kubantsev MA, Kubarovsky VP, Kulyavtsev AI, Kuropatkin NP, Kurshetsov VF, Kushnirenko A, Kwan S, Lach J, Lamberto A, Landsberg LG, Larin I, Leikin EM, Luksys M, Lungov T, Magarrel D, Maleev VP, Mao D, Masciocchi S, Mathew P, Mattson M, Matveev V, McCliment E, McKenna SL, Moinester MA, Molchanov VV, Morelos A, Mukhin VA, Nelson KD, Nemitkin AV, Neoustroev PV, Newsom C, Nilov AP, Nurushev SB, Ocherashvili A, Oleynik G, Onel Y, Ozel E, Ozkorucuklu S, Patrichev S, Penzo A, Petrenko SI, Pogodin P, Povh B, Procario M, Prutskoi VA, Ramberg E, Rappazzo GF, Razmyslovich BV, Rud VI, Russ J, Schiavon P, Semyatchkin VK, Simon J, Sitnikov AI, Skow D, Smith VJ, Srivastava M, Steiner V, Stepanov V, Stutte L, Svoiski M, Terentyev NK, Thomas GP, Uvarov LN, Vasiliev AN, Vavilov DV, Verebryusov VS, Victorov VA, Vishnyakov VE, Vorobyov AA, Vorwalter K, Wenheng Z, You J, Yunshan L, Zhenlin M, Zhigang L, and Zukanovich Funchal R
- Abstract
We report the first observation of the Cabibbo-suppressed charm baryon decay Ξ_{c}^{+}→pK^{-}π^{+}. We observe 150±22±5 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Σ^{-} beam. The branching fractions of the decay relative to the Cabibbo-favored Ξ_{c}^{+}→Σ^{+}K^{-}π^{+} and Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} are measured to be B(Ξ_{c}^{+}→pK^{-}π^{+})/B(Ξ_{c}^{+}→Σ^{+}K^{-}π^{+})=0.22±0.06±0.03 and B(Ξ_{c}^{+}→pK^{-}π^{+})/B(Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+})=0.20±0.04±0.02, respectively.
- Published
- 2000
- Full Text
- View/download PDF
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