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Recent measurements by the Belle Collaboration of the exclusive production of two charmonia in e(+)e(-) annihilation differ substantially from theoretical predictions. We suggest that a significant part of the discrepancy can be explained by the process e(+)e(-)-->J/psi+J/psi. Because the J/psi+J/psi production process can proceed through fragmentation of two virtual photons into two cc pairs, its cross section may be larger than that for J/psi+eta(c) by about a factor of 3.7, in spite of a suppression factor alpha(2)/alpha(2)(s) that is associated with the QED and QCD coupling constants. 相似文献
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Adam NE Alexander JP Berkelman K Cassel DG Crede V Duboscq JE Ecklund KM Ehrlich R Fields L Galik RS Gibbons L Gittelman B Gray R Gray SW Hartill DL Heltsley BK Hertz D Hsu L Jones CD Kandaswamy J Kreinick DL Kuznetsov VE Mahlke-Krüger H Meyer TO Onyisi PU Patterson JR Peterson D Phillips EA Pivarski J Riley D Ryd A Sadoff AJ Schwarthoff H Shepherd MR Stroiney S Sun WM Urner D Wilksen T Weinberger M Athar SB Avery P Breva-Newell L Patel R Potlia V Stoeck H Yelton J Rubin P Cawlfield C 《Physical review letters》2005,94(23):232002
We describe new measurements of the inclusive and exclusive branching fractions for psi(2S) transitions to J/psi using e(+)e(-) collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching fractions reported here represent either the most precise measurements to date or the first direct measurements. Indirectly and in combination with other CLEO measurements, we determine B(chi(cJ) --> gamma(J/psi)) and B[psi(2S) --> light hadrons]. 相似文献
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Choi SK Olsen SL Abe K Abe K Adachi I Aihara H Asano Y Bahinipati S Bakich AM Ban Y Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chen A Chen WT Cheon BG Chistov R Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Enari Y Fang F Fratina S Gabyshev N Gershon T Gokhroo G Golob B Hara T Hastings NC Hayasaka K Hayashii H Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Iijima T Imoto A Inami K Ishikawa A Iwasaki M 《Physical review letters》2005,94(18):182002
We report the observation of a near-threshold enhancement in the omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from a 253 fb(-1) data sample that contains 275 x 10(6) BB pairs that were collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. The statistical significance of the omegaJ/psi mass enhancement is estimated to be greater than 8sigma. 相似文献
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Armstrong TA Bettoni D Bharadwaj V Biino C Borreani G Broemmelsiek D Buzzo A Calabrese R Ceccucci A Cester R Church MD Dalpiaz P Dalpiaz PF Dibenedetto R Dimitroyannis D Fabbri MG Fast JE Gianoli A Ginsburg CM Gollwitzer KE Hahn AA Hasan MA Hsueh SY Lewis RA Luppi E Macrí M Majewska A Mandelkern MA Marchetto F Marinelli M Marques JL Marsh W Martini M Masuzawa M Menichetti E Migliori A Mussa R Palestini S Pallavicini M Passaggio S Pastrone N Patrignani C Peoples J Pesando L Petrucci F Pia MG 《Physical review D: Particles and fields》1993,47(3):772-783
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Schub MH Jansen DM Mishra CS Ho PM Brown CN Carey TA Chen YC Childers R Cooper WE Darden CW Gidal G Gounder KN Isenhower LD Jeppesen RG Kaplan DM Kapustinsky JS Kiang GC Kowitt MS Lane DW Lederman LM Leitch MJ Lillberg JW Luebke WR Luk KB McGaughey PL Moss JM Peng JC Preston RS Pripstein D Sa J Sadler ME Schnathorst R Tanikella V Teng PK Wilson JR 《Physical review D: Particles and fields》1996,53(1):570
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Ablikim M Bai JZ Ban Y Cai X Chen HF Chen HS Chen HX Chen JC Chen J Chen YB Chu YP Dai YS Diao LY Deng ZY Dong QF Du SX Fang J Fang SS Fu CD Gao CS Gao YN Gu SD Gu YT Guo YN Guo ZJ Harris FA He KL He M Heng YK Hou J Hu HM Hu JH Hu T Huang XT Ji XB Jiang XS Jiang XY Jiao JB Jin DP Jin S Jin Y Lai YF Li G Li HB Li J Li RY Li SM Li WD Li WG Li XL Li XN Li XQ Liang YF Liao HB Liu BJ Liu CX Liu F Liu F Liu HH Liu HM Liu J Liu JB Liu JP Liu J Liu Q Liu RG Liu ZA Lou YC Lu F Lu GR Lu JG Luo CL Ma FC 《Physical review letters》2008,100(19):192001
Using psi(2S) --> pi(+)pi(-) J/psi events in a sample of 14.0 x 10(6) psi(2S) decays collected with the BES-II detector, a search for the decay of the J/psi to invisible final states is performed. No signal is found, and an upper limit at the 90% confidence level is determined to be 1.2 x 10(-2) for the ratio B(J/psi --> invisible)/B(J/psi-->mu(+)mu(-)). This is the first search for J/psi decays to invisible final states. 相似文献
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We study J/psi production at RHIC and LHC energies with both initial production at energies reached and the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) with regeneration. We solve the coupled set of transport equations for the J/psi distribution in phase space and the hydrodynamic equation for evolution of quark-gluon plasma. At RHIC, continuous regeneration is crucial for the J/psi momentum distribution while the elliptic flow is still dominated by initial production. At energies reached at the LHC energy, almost all the initially created J/psis are dissociated in the medium and regeneration dominates the J/psi properties. 相似文献
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Milana J 《Physical review letters》1989,62(25):2921-2924
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Antoniazzi L Arenton M Cao Z Chen T Conetti S Corti G Cox B Delchamps S Fortney L Guffey K Haire M Ioannou P Jenkins CM Judd DJ Kourkoumelis C Manousakis-Katsikakis A Kuzminski J LeCompte T Marchionni A He M Mazur PO Murphy CT Pramantiotis P Rameika R Resvanis LK Rosati M Rosen J Shen C Shen Q Simard A Smith RP Spiegel L Stairs DG Tan Y Tesarek RJ Turkington T Turnbull L Turkot F Tzamarias S Voulgaris G Wagoner DE Wang C Yang W Yao N Zhang N Zhang X Zioulas G Zou B 《Physical review D: Particles and fields》1994,50(7):4258-4264
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We propose a model for calculating J/psi suppression in high-energy hadron-nucleus and nucleus-nucleus collisions. We factorized the process into a production of the cc- pairs convoluted with a transition probability into the observed J/psi mesons. As the produced cc- pairs exit the nuclear matter, multiple scattering increases the square of the relative momentum between the c and c- such that some pairs are transmuted into open charm states. With only one parameter, the energy gained by the produced cc- pair per unit length in the nuclear medium, our model can fit all observed J/psi suppression data in hadron-nucleus and nucleus-nucleus collisions. 相似文献
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Miller DH Sanghi B Shipsey IP Xin B Adams GS Anderson M Cummings JP Danko I Ge JY Hu D Moziak B Napolitano J He Q Insler J Muramatsu H Park CS Thorndike EH Yang F Artuso M Blusk S Khalil S Li J Menaa N Mountain R Nisar S Randrianarivony K Sia R Skwarnicki T Stone S Wang JC Bonvicini G Cinabro D Dubrovin M Lincoln A Asner DM Edwards KW Naik P Briere RA Ferguson T Tatishvili G Vogel H Watkins ME Rosner JL Adam NE Alexander JP Cassel DG Duboscq JE Ehrlich R Fields L Gibbons L Gray R Gray SW 《Physical review letters》2007,99(12):122002
We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM. 相似文献
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Leitch MJ Lee WM Beddo ME Brown CN Carey TA Chang TH Cooper WE Gagliardi CA Garvey GT Geesaman DF Hawker EA He XC Isenhower LD Kaplan DM Kaufman SB Koetke DD McGaughey PL Moss JM Mueller BA Papavassiliou V Peng JC Petitt G Reimer PE Sadler ME Sondheim WE Stankus PW 《Physical review letters》2000,84(15):3256-3260
Measurements of the suppression of the yield per nucleon of J/psi and psi(') production for 800 GeV/ c protons incident on heavy nuclear targets, relative to light nuclear targets, have been made with very broad coverage in x(F) and p(T). The observed suppression is smallest at x(F) values of 0.25 and below, and increases at larger values of x(F). It is also strongest at small p(T). Substantial differences between psi(') and J/psi production are observed for the first time in p-A collisions. The suppression for psi(') production is stronger than that for J/psi for x(F) near zero, but becomes comparable to that for J/psi for x(F)>0.6. 相似文献
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Adam NE Alexander JP Berkelman K Cassel DG Crede V Duboscq JE Ecklund KM Ehrlich R Fields L Galik RS Gibbons L Gittelman B Gray R Gray SW Hartill DL Heltsley BK Hertz D Jones CD Kandaswamy J Kreinick DL Kuznetsov VE Mahlke-Krüger H Meyer TO Onyisi PU Patterson JR Peterson D Phillips EA Pivarski J Riley D Ryd A Sadoff AJ Schwarthoff H Shi X Shepherd MR Stroiney S Sun WM Urner D Wilksen T Weaver KM Weinberger M Athar SB Avery P Breva-Newell L Patel R Potlia V Stoeck H Yelton J Rubin P Cawlfield C 《Physical review letters》2006,96(8):082004
We observe signals for the decays psi(3770) --> XJ/psi from data acquired with the CLEO detector operating at the CESR e+ e- collider with square root of s = 3773 MeV. We measure the following branching fractions Beta(psi(3770) --> XJ/psi and significances: (189 +/- 20 +/- 20) x 10(-5) (11.6sigma) for X = pi+ pi-, (80 +/- 25 +/- 16) x 10(-5) (3.4sigma) for X = pi0 pi0, and (87 +/- 33 +/- 22) x 10(-5) (3.5sigma) for X = eta, where the errors are statistical and systematic, respectively. The radiative return process e+ e- --> gamma psi(2S) populates the same event sample and is used to measure Gamma ee[psi(2S)] = (2.54 +/- 0.03 +/- 0.11) keV. 相似文献