共查询到20条相似文献,搜索用时 31 毫秒
1.
Bolton T Brown JS Bunnell KO Burchell M Burnett TH Cassell RE Coffman D Coward DH Coyle P DeJongh F Drinkard J Dubois GP Eigen G Eisenstein BI Freese T Gatto C Gladding G Heusch CA Hitlin DG Izen JM Kim PC Labs J Li A Lockman WS Mallik U Matthews CG Mir R Mockett PM Odian A Parrish L Pitman D Richman JD Sadrozinski HF Scarlatella M Schalk TL Schindler RH Seiden A Stockdale IE Toki W Tripsas B Wang MZ Weinstein AJ Weseler S Willutzki HJ Wisniewski WJ Xu R Zhu Y 《Physical review letters》1992,69(9):1328-1331
2.
Armstrong TA Bettoni D Bharadwaj V Biino C Borreani G Broemmelsiek D Buzzo A Calabrese R Ceccucci A Cester R Church M Dalpiaz P Dalpiaz PF Dimitroyannis D Fabbri M Fast J Gianoli A Ginsburg CM Gollwitzer K Govi G Hahn A Hasan M Hsueh S Lewis R Luppi E Macrí M Majewska AM Mandelkern M Marchetto F Marinelli M Marques J Marsh W Martini M Masuzawa M Menichetti E Migliori A Mussa R Palestini S Pallavicini M Passaggio S Pastrone N Patrignani C Peoples J Petrucci F Pia MG Pordes S Rapidis P Ray R 《Physical review D: Particles and fields》1996,54(11):7067-7070
3.
We present theoretical predictions for the transverse-momentum distribution of J/psi mesons promptly produced in gammagamma collisions within the factorization formalism of nonrelativistic quantum chromodynamics, including the contributions from both direct and resolved photons, and we perform a conservative error analysis. The fraction of J/psi mesons from decays of bottom-flavored hadrons is estimated to be negligibly small. New data taken by the DELPHI Collaboration at LEP2 nicely confirm these predictions, while they disfavor those obtained within the traditional color-singlet model. 相似文献
4.
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 AM Mandelkern MA Marchetto F Marinelli M Marques JL Marsh W Martini M Masuzawa M Menichetti E Migliori A Mussa R Palestini S Pallavicini M Pastrone N Patrignani C Peoples J Pesando L Petrucci F Pia MG Pordes S 《Physical review D: Particles and fields》1993,48(7):3037-3044
5.
Coffman D DeJongh F Dubois G Eigen G Hauser J Hitlin DG Matthews CG Mincer A Richman JD Wisniewski WJ Zhu Y Burchell M Dorfan DE Drinkard J Gatto C Hamilton RP Heusch CA Köpke L Lockman WS Partridge R Sadrozinski HF Scarlatella M Schalk TL Seiden A Weinstein AJ Weseler S Xu R Becker JJ Blaylock GT Eisenstein BI Freese T Gladding G Izen JM Plaetzer SA Simopoulos C Spadafora AL Stockdale IE Tripsas B Mallik U Roco M Wang MZ Adler J Bolton T Brient JC Bunnell KO Cassell RE Coward DH Einsweiler KF 《Physical review D: Particles and fields》1990,41(5):1410-1413
6.
Abe F Albrow MG Amendolia SR Amidei D Antos J Anway-Wiese C Apollinari G Areti H Atac M Auchincloss P Azfar F Azzi P Bacchetta N Badgett W Bailey MW Bao J de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Bartalini P Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Benton D Beretvas A Berge JP Bertolucci S Bhatti A Biery K Binkley M Bird F Bisello D Blair RE Blocker C Bodek A Bokhari W Bolognesi V Bortoletto D Boswell C Boulos T 《Physical review letters》1996,76(12):2015-2020
7.
8.
9.
10.
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
11.
Bai JZ Bian JG Chai ZW Chen GP Chen HF Chen JC Chen SM Chen Y Chen YB Chen YQ Cheng BS Cheng ZD Cui XZ Ding HL Ding WY Du ZZ Fan XL Fang J Gao CS Gao ML Gao SQ Gu JH Gu SD Gu WX Gu YF Guo YN Han SW Han Y He J He JT He M Hu GY Hu JL Hu QH Hu T Hu XQ Huang XP Huang YZ Jiang CH Jin S Jin Y Kang SH Ke ZJ Lai YF Lan HB Lang PF Li J Li PQ Li Q Li RB Li W Li WD Li WG Li XH Li XN Lin SZ Liu HM Liu J Liu JH Liu Q Liu RG Liu Y Liu ZA Lu F 《Physical review letters》1996,77(19):3959-3962
12.
Bai Z Blaylock GT Bolton T Brient JC Browder T Brown JS Bunnell KO Burchell M Burnett TH Cassell RE Coffman D Cook V Coward DH DeJongh F Dorfan DE Drinkard J Dubois GP Eigen G Einsweiler KF Eisenstein BI Freese T Gatto C Gladding G Grab C Hauser J Heusch CA Hitlin DG Izen JM Kim PC Labs J Li A Lockman WS Mallik U Matthews CG Mincer AI Mir R Mockett PM Nemati B Odian A Parrish L Partridge R Pitman D Plaetzer SA Richman JD Sadrozinski HF Scarlatella M Schalk TL Schindler RH Seiden A Simopoulos C 《Physical review letters》1990,65(20):2507-2510
13.
14.
15.
Bai Z Blaylock GT Bolton T Browder TE Brown JS Bunnell KO Burnett TH Cassell RE Coffman D Cook V DeJongh F Dorfan DE Drinkard J Dubois GP Eigen G Einsweiler KF Eisenstein BI Freese T Gatto C Gladding G Hauser J Heusch CA Hitlin DG Izen JM Kim PC Labs J Li A Lockman WS Mallik U Matthews CG Mincer AI Mir R Mockett PM Mozley RF Nemati B Odian A Parrish L Partridge R Pitman D Plaetzer SA Richman JD Sadrozinski HF Scarlatella M Schalk TL Schindler RH Seiden A Simopoulos C Stockdale IE Toki W 《Physical review letters》1990,65(11):1309-1312
16.
Jousset J Ajaltouni Z Falvard A Jnad H Michel B Montret JC Bisello D Busetto G Castro A Pescara L Racioppi F Sartori P Stanco L Augustin JE Cosme G Couchot F Fulda F Grosdidier G Jean-Marie B Lepeltier V Mane F Szklarz G Baldini R Schioppa M 《Physical review D: Particles and fields》1990,41(5):1389-1400
17.
Double-charm production e+e- -->J/psi + cc at B factories with next-to-leading-order QCD corrections
The inclusive J/psi production in e;{+}e;{-}-->J/psicc at B factories is one of the most challenging open problems in heavy quarkonium physics. The observed cross section of this double-charm production process is larger than existing leading order (LO) QCD predictions by a factor of 5. In the nonrelativistic QCD (NRQCD) factorization formalism, we calculate the next-to-leading order (NLO) QCD virtual and real corrections to this process, and find that these corrections can substantially enhance the cross section with a K factor of about 1.8. We further take into account the feeddown contributions from higher charmonium states [mainly the psi(2S) as well as chi_{cJ}] and the two-photon contributions, and find that the discrepancy between theory and experiment can be largely removed. 相似文献
18.
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
19.
Abulencia A Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Azzurri P Bacchetta N Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Bartsch V Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Blair RE Blocker C Blumenfeld B Bocci A 《Physical review letters》2007,98(23):232001
We measure the ratio of cross section times branching fraction, Rp=sigma chi c2 B(chi c2-->J/psi gamma)/sigma chi c1 B(chi c1-->J/psi gamma), in 1.1 fb(-1) of pp collisions at square root s=1.96 TeV. This measurement covers the kinematic range pT(J/psi)>4.0 GeV/c, |eta(J/psi)<1.0, and pT(gamma)>1.0 GeV/c. For events due to prompt processes, we find Rp=0.395+/-0.016(stat)+/-0.015(syst). This result represents a significant improvement in precision over previous measurements of prompt chi c1,2 hadro production. 相似文献
20.
Yuan CZ Shen CP Wang P McOnie S Adachi I Aihara H Aulchenko V Aushev T Bahinipati S Balagura V Barberio E Bedny I Bitenc U Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chen A Chen KF Chen WT Cheon BG Chistov R Cho IS Choi Y Dalseno J Danilov M Dash M Eidelman S Fratina S Gabyshev N Golob B Ha H Haba J Hayasaka K Hayashii H Hazumi M Heffernan D Hokuue T Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Ikado K Inami K Ishikawa A Itoh R Iwasaki Y Kah DH Kaji H Kang JH Katayama N 《Physical review letters》2007,99(18):182004
The cross section for e(+)e(-)-->pi(+)pi(-)J/psi between 3.8 and 5.5 GeV/c(2) is measured using a 548 fb(-1) data sample collected on or near the Upsilon(4S) resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c(2), corresponding to the so called Y(4260), is observed. In addition, there is another cluster of events at around 4.05 GeV/c(2). A fit using two interfering Breit-Wigner shapes describes the data better than one that uses only the Y(4260), especially for the lower-mass side of the 4.25 GeV enhancement. 相似文献