Motivated by the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕand the light exotic candidates,we found that there may exist molecular states composed of f0(1710)ωand f0(1710)ϕ,which correspond to X(2440)and...Motivated by the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕand the light exotic candidates,we found that there may exist molecular states composed of f0(1710)ωand f0(1710)ϕ,which correspond to X(2440)and X(2680)observed a few decades ago.The branching fractions of X(2440)and X(2680)to various PV and KKω(ϕ)channels were estimated in the molecular scenario.In addition,the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕindicate sizable molecular components in the J/ψstate.Thus,we consider J/ψas the superposition of thecc¯(1S),f0(1710)ω,and f0(1710)ϕmolecular states.These molecular components have a significant impact on the light hadron decays of J/ψ,which may elucidate the long standingρ−πpuzzle.展开更多
We explored a new approach to search for a low-mass Z′particle through J/ψdecays by identifying its existence through parity-violating phenomena in the isospin-violating final states ofΛΣ¯^(0)and the correspo...We explored a new approach to search for a low-mass Z′particle through J/ψdecays by identifying its existence through parity-violating phenomena in the isospin-violating final states ofΛΣ¯^(0)and the corresponding charge conjugated states ofΛΣ¯^(0).Our investigation centered on a generation-independent and leptophobic Z′with mass below 10 GeV.Given the present experimental conditions at Beijing Spectrometer III(BESIII)and the anticipated opportunities at the Super Tau Charm Factory(STCF),we conducted Monte-Carlo simulations to predict possible events at both facilities.Notably,we foresee a substantial enhancement in the precision of the lower limit estimation ofαNP as well as a reduction in statistical uncertainty with upcoming STCF experiments.Furthermore,it is essential to highlight that a null result in the measurement ofαNP would impose stringent constraints,requiring the Z′−q−q couplings to be in the order of 10^(−2).展开更多
A measurement of the number of J/ψ events collected with the BESⅢ detector in 2009 and 2012 is performed using inclusive decays of the J/ψ. The number of J/ψ events taken in 2009 is recalculated to be（223.7±...A measurement of the number of J/ψ events collected with the BESⅢ detector in 2009 and 2012 is performed using inclusive decays of the J/ψ. The number of J/ψ events taken in 2009 is recalculated to be（223.7±1.4）×10^6, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESⅢ software. The number of J/ψ events taken in 2012 is determined to be（1086.9±6.0）×10^6. In total, the number of J/ψ events collected with the BESⅢ detector is measured to be（1310.6±7.0）×10^6, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.展开更多
The number of J/ψ events collected with the BES detector at the BEPC from June 12 to July 28, 2009 is determined to be （225.3 ± 2.8） × 10^ 6 using J/ψ→inclusive events, where the uncertainty is the syst...The number of J/ψ events collected with the BES detector at the BEPC from June 12 to July 28, 2009 is determined to be （225.3 ± 2.8） × 10^ 6 using J/ψ→inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.展开更多
The medium modifications of J/ψ production in d-Au collisions at SNN = 200 GeV are studied in the Glauber model. By means of the c.m. energy loss parameter per collision studied in Drell-Yan process, taking account o...The medium modifications of J/ψ production in d-Au collisions at SNN = 200 GeV are studied in the Glauber model. By means of the c.m. energy loss parameter per collision studied in Drell-Yan process, taking account of the inhomogeneous shadowing effect, we find that the initial-state energy loss effect can be ignored in d-Au collisions at mid-rapidity. Then, the final-state J/ψ absorption effect is also considered and the theoretical results are in good agreement with the recent experimental data given by PHENIX. Finally, the experimental results of J/ψ production in d-Pb collisions are also predicted at RHIC and LHC energies respectively.展开更多
The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov ap...The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov approach,we calculate the cross section and the nuclear modification factor of forward J/ψ production in p+Pb collisions at s^(1/2) 5:02 TeV.Then,the backward J/ψ production in p+Pb collisions at s^(1/2) 8:16 Te V is also analyzed.In our calculation,the phenomenology KLRAd S/CFT model and the rc BK approach,which are valid at a small x,are used to calculate the three-point function.It is shown that the theoretical results fit well with the experimental data from ALICE and LHCb.展开更多
Using ～ 14 × 10^6 ψ（2S） and ～ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ（2S）→Ω-Ω^＋ is measured with about 5a statistical significance. The A electric dipole and ∧...Using ～ 14 × 10^6 ψ（2S） and ～ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ（2S）→Ω-Ω^＋ is measured with about 5a statistical significance. The A electric dipole and ∧ decay parameter are studied using the decay J/ψ →∧∧→ ppπ^＋π^-. Using （106±3）× 10^6 ψ（2S） decays collected at BESⅢ/BEPC Ⅱ, we have obtained some interesting physics results. The branching fractions of XcJ→π^0π^0, ηη are measured with precision improved. The mass and width of he（l^1P1） state, together with the branching fractions of Br（ψ（2S） →π^0hc） and Br（hc →γηc） are the first measurements. Surprisingly, the decays of Xc1→φφ, ωω, and ωφ are firstly observed in BESⅢ data.展开更多
The energy loss effect of incoming gluons from J/ψ production in p-A（or d-A） collisions is investigated by means of the E866, RHIC and LHC experimental data. The gluon mean energy loss per unit path length d E/d L ...The energy loss effect of incoming gluons from J/ψ production in p-A（or d-A） collisions is investigated by means of the E866, RHIC and LHC experimental data. The gluon mean energy loss per unit path length d E/d L = 2.18 ± 0.14 Ge V/fm is extracted by fitting the E866 experimental data for J/ψ production cross section ratios R W（Fe）/Be（x F）. The obtained result indicates that the incoming gluons lose more energy than the incident quarks. By comparing the theoretical results with E866, RHIC, and LHC experimental data, it is found that the nuclear suppression due to the incident gluon（quark） energy loss reduces（increases） with the increase of the kinematic variable x F（or y）. The energy loss effect of incoming gluons plays an important role in the suppression of J/ψ production in a wide energy range from√s = 38.7 Ge V to√s = 5.0 Te V, and the influence of incident quark energy loss can be ignored for high energies（such as at RHIC and LHC energy）.展开更多
We report the methods and plans for measuring the differential cross section of J/ψ→μ^＋μ^- production, using data to be collected in the first LHC run by the CMS detector. Making use of the large B-hadron lifetim...We report the methods and plans for measuring the differential cross section of J/ψ→μ^＋μ^- production, using data to be collected in the first LHC run by the CMS detector. Making use of the large B-hadron lifetime, we show how to separate the promptly produced J/ψ’s from those coming from B-hadron decays. Since the J/ψ production cross section is expected to be large, the analysis should be viable with relatively small data sets, that will become available early in the startup of the LHC. We also address effects of a non-perfect detector alignment, as well as systematic uncertainties. About 70 thousand J/ψ decays are reconstructed from Monte Carlo data, which corresponds to an integrated luminosity of 3 pb^-1 in 14 TeV collisions, in the range of pT^J/ ψbetween 5 and 40 GeV/c. The precision of the result is limited by systematic uncertainties, and is at the 15% level.展开更多
Based on the branching fractions of J/ψ→VP from different experiments, we investigate the properties of the coupling constants of J/ψ→ VP decays using a model-dependent approach. We find that the octet coupling co...Based on the branching fractions of J/ψ→VP from different experiments, we investigate the properties of the coupling constants of J/ψ→ VP decays using a model-dependent approach. We find that the octet coupling constant, gs, of strong interaction is about twice larger than that of the singlet coupling constant g1; the electromag- netic breaking parameters g_E^i are larger than the mass breaking parameters g_M^i, moreover, the three parameters of the electromagnetic effect are about equal, but the three parameters of the mass effect are obviously different and their uncertainties are also large; and the phase angle between strong and electromagnetic interactions is in the range of 700-80°. It deepens our understanding of the coupling constant of J/ψ→VP decays.展开更多
The helicity amplitudes for Jψ→ ∧∧ and the relevant background decays are presented for measuring the ∧ decay parameter α ＋（∧ → pπ^＋） in J/ψ→ ∧∧. The Monte Carlo （MC） simulations based on the helici...The helicity amplitudes for Jψ→ ∧∧ and the relevant background decays are presented for measuring the ∧ decay parameter α ＋（∧ → pπ^＋） in J/ψ→ ∧∧. The Monte Carlo （MC） simulations based on the helicity amplitudes information are carried out. The likelihood fit method to determine the .∧ decay parameter is presented. Based on the MC generated sample, the sensitivity of the measurement for α＋ has been estimated, which shows that the J/ψ→ ∧∧ channel can be used to measure the .∧ decay parameter α＋（∧ → pπ^＋） well.展开更多
We study the decay process of J/ψ→ e＋e-φ where the relatively clean electromagnetic （EM） transitions appear at leading order at tree level while the hadronic contributions only emerge via hadronic loop transitio...We study the decay process of J/ψ→ e＋e-φ where the relatively clean electromagnetic （EM） transitions appear at leading order at tree level while the hadronic contributions only emerge via hadronic loop transitions. We include the low-lying scalar f0（980） and pseudoscalar η/η′ as the dominant contributions in the evaluation of the hadronic loop contributions. It is found that the hadronic effects are negligible compared with the EM contributions. The decay width of J/ψ→ e＋e-φis determined to be about 2.12 × 10^-6 keV if there is no other leading mechanism contributing. This result will be tested by the BESIII experiment with a large J/ψ data sample.展开更多
J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for...J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for J/ψproduction cross-section ratios RW/Be（x F） are presented and compared with the selected E866 experimental data with the cc remaining colored on its entire path in the medium. It is shown that the combination of the different nuclear effects accounts quite well for the observed J/ψ suppression in the experimental data. It is found that the J/ψ suppression on RW/Be（x F） from the initial state nuclear effects is more important than that induced by the energy loss of color octet cc in the large x F region. Whether the cc pair energy loss is linear or quadratic with the path length is not determined. The obtained cc pair energy loss per unit path length α = 2.78±0.81 Ge V/fm, which indicates that the heavy quark in cold nuclear matter can lose more energy compared to the outgoing light quark.展开更多
With three theoretical models of nuclear effects on gluon distribution functions,the differentialcross sections and the total cross sections for associate production of J/ψ and γ with large P_T in high energyp-Fe co...With three theoretical models of nuclear effects on gluon distribution functions,the differentialcross sections and the total cross sections for associate production of J/ψ and γ with large P_T in high energyp-Fe collisions are calculated.展开更多
The absorption cross section σ<sub>abs</sub> of J/ψ produced in relativistic heavy ioncollisions is deduced based on the analysis of the absorption length through which theproduced J/ψ passes in the col...The absorption cross section σ<sub>abs</sub> of J/ψ produced in relativistic heavy ioncollisions is deduced based on the analysis of the absorption length through which theproduced J/ψ passes in the colliding nuclei.The obtained σ<sub>abs</sub> in A-A collisions is con-siderably higher than that in h-A processes.The reason for this different result is dis-cussed in terms of an analysis of the p<sub>T</sub>-dependence of the produced J/ψ.展开更多
基金Supported by National Natural Science Foundation of China(11805160,11747040,11675082)Qinglan Project of Jiangsu Province in 2021。
文摘Motivated by the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕand the light exotic candidates,we found that there may exist molecular states composed of f0(1710)ωand f0(1710)ϕ,which correspond to X(2440)and X(2680)observed a few decades ago.The branching fractions of X(2440)and X(2680)to various PV and KKω(ϕ)channels were estimated in the molecular scenario.In addition,the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕindicate sizable molecular components in the J/ψstate.Thus,we consider J/ψas the superposition of thecc¯(1S),f0(1710)ω,and f0(1710)ϕmolecular states.These molecular components have a significant impact on the light hadron decays of J/ψ,which may elucidate the long standingρ−πpuzzle.
基金Supported in part by the National Key Research and Development Program of China under(2020YFC2201501)the National Natural Science Foundation of China(NSFC)(12347103,12205063)。
文摘We explored a new approach to search for a low-mass Z′particle through J/ψdecays by identifying its existence through parity-violating phenomena in the isospin-violating final states ofΛΣ¯^(0)and the corresponding charge conjugated states ofΛΣ¯^(0).Our investigation centered on a generation-independent and leptophobic Z′with mass below 10 GeV.Given the present experimental conditions at Beijing Spectrometer III(BESIII)and the anticipated opportunities at the Super Tau Charm Factory(STCF),we conducted Monte-Carlo simulations to predict possible events at both facilities.Notably,we foresee a substantial enhancement in the precision of the lower limit estimation ofαNP as well as a reduction in statistical uncertainty with upcoming STCF experiments.Furthermore,it is essential to highlight that a null result in the measurement ofαNP would impose stringent constraints,requiring the Z′−q−q couplings to be in the order of 10^(−2).
基金Supported by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(10805053,11125525,11175188,11235011,11322544,11335008,11425524)+15 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics(CCEPP)Collaborative Innovation Center for Particles and Interactions(CICPI)Joint Large-Scale Scientific Facility Funds of NSFC and CAS(11179007,U1232201,U1232107,U1332201)CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,INPACShanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey(DPT2006K-120470)Russian Foundation for Basic Research(14-07-91152)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science FoundationUniversity of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),DarmstadtWCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘A measurement of the number of J/ψ events collected with the BESⅢ detector in 2009 and 2012 is performed using inclusive decays of the J/ψ. The number of J/ψ events taken in 2009 is recalculated to be（223.7±1.4）×10^6, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESⅢ software. The number of J/ψ events taken in 2012 is determined to be（1086.9±6.0）×10^6. In total, the number of J/ψ events collected with the BESⅢ detector is measured to be（1310.6±7.0）×10^6, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.
基金Supported by Ministry of Science and Technology of China (2009CB825200)National Natural Science Foundation of China (NSFC) (10625524, 10821063, 10825524, 10835001, 10935007, 11125525)+3 种基金Joint Funds of National Natural Science Foundation of China (11079008, 11179007)Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program (KJCX2-YW-N29, KJCX2-YW-N45)100 Talents Program of CAS, Istituto Nazionale di Fisica Nucleare, Italy, U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-91ER40682, DE-FG02-94ER40823)U.S. National Science Foundation, University of Groningen (RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt, WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0)
文摘The number of J/ψ events collected with the BES detector at the BEPC from June 12 to July 28, 2009 is determined to be （225.3 ± 2.8） × 10^ 6 using J/ψ→inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.
基金Supported by Innovation Foundation of Academy of Armored Forces Engineering of PLA (20062L10)Natural Science Foundation of Hebei Province (A2005000535)
文摘The medium modifications of J/ψ production in d-Au collisions at SNN = 200 GeV are studied in the Glauber model. By means of the c.m. energy loss parameter per collision studied in Drell-Yan process, taking account of the inhomogeneous shadowing effect, we find that the initial-state energy loss effect can be ignored in d-Au collisions at mid-rapidity. Then, the final-state J/ψ absorption effect is also considered and the theoretical results are in good agreement with the recent experimental data given by PHENIX. Finally, the experimental results of J/ψ production in d-Pb collisions are also predicted at RHIC and LHC energies respectively.
基金supported by the Natural Science Foundation of Hebei Province(A2012210043)
文摘The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov approach,we calculate the cross section and the nuclear modification factor of forward J/ψ production in p+Pb collisions at s^(1/2) 5:02 TeV.Then,the backward J/ψ production in p+Pb collisions at s^(1/2) 8:16 Te V is also analyzed.In our calculation,the phenomenology KLRAd S/CFT model and the rc BK approach,which are valid at a small x,are used to calculate the three-point function.It is shown that the theoretical results fit well with the experimental data from ALICE and LHCb.
基金Supported by National Natural Science Foundation of China (10491300,10225524,10225525,10425523,10625524,10521003,10821063,10825524)Chinese Academy of Sciences (KJ 95T-03)+2 种基金100 Talents Program of CAS (U-11,U-24,U-25)Knowledge Innovation Project of CAS (U-602,U-34 (IHEP))National Natural Science Foundation of China (10225522 (Tsinghua University))
文摘Using ～ 14 × 10^6 ψ（2S） and ～ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ（2S）→Ω-Ω^＋ is measured with about 5a statistical significance. The A electric dipole and ∧ decay parameter are studied using the decay J/ψ →∧∧→ ppπ^＋π^-. Using （106±3）× 10^6 ψ（2S） decays collected at BESⅢ/BEPC Ⅱ, we have obtained some interesting physics results. The branching fractions of XcJ→π^0π^0, ηη are measured with precision improved. The mass and width of he（l^1P1） state, together with the branching fractions of Br（ψ（2S） →π^0hc） and Br（hc →γηc） are the first measurements. Surprisingly, the decays of Xc1→φφ, ωω, and ωφ are firstly observed in BESⅢ data.
基金supported by the National Natural Science Foundation of China (11775213, 12005220)the USTC Research Funds of the Double First-Class Initiative(YD2360002001)。
基金Supported by National Natural Science Foundation of China(11405043,11575052)
文摘The energy loss effect of incoming gluons from J/ψ production in p-A（or d-A） collisions is investigated by means of the E866, RHIC and LHC experimental data. The gluon mean energy loss per unit path length d E/d L = 2.18 ± 0.14 Ge V/fm is extracted by fitting the E866 experimental data for J/ψ production cross section ratios R W（Fe）/Be（x F）. The obtained result indicates that the incoming gluons lose more energy than the incident quarks. By comparing the theoretical results with E866, RHIC, and LHC experimental data, it is found that the nuclear suppression due to the incident gluon（quark） energy loss reduces（increases） with the increase of the kinematic variable x F（or y）. The energy loss effect of incoming gluons plays an important role in the suppression of J/ψ production in a wide energy range from√s = 38.7 Ge V to√s = 5.0 Te V, and the influence of incident quark energy loss can be ignored for high energies（such as at RHIC and LHC energy）.
基金Supported by NSFC (10099630)Ministry of Science and Technology of China (2007CB816101)
文摘We report the methods and plans for measuring the differential cross section of J/ψ→μ^＋μ^- production, using data to be collected in the first LHC run by the CMS detector. Making use of the large B-hadron lifetime, we show how to separate the promptly produced J/ψ’s from those coming from B-hadron decays. Since the J/ψ production cross section is expected to be large, the analysis should be viable with relatively small data sets, that will become available early in the startup of the LHC. We also address effects of a non-perfect detector alignment, as well as systematic uncertainties. About 70 thousand J/ψ decays are reconstructed from Monte Carlo data, which corresponds to an integrated luminosity of 3 pb^-1 in 14 TeV collisions, in the range of pT^J/ ψbetween 5 and 40 GeV/c. The precision of the result is limited by systematic uncertainties, and is at the 15% level.
基金Supported by the National Natural Science Foundation of China (10979008)Program for Science and Technology Innovation Talents in Universities of He’nan Province (2012HASTIT030)the Natural Science Foundation of He’nan Province (102300410210)
文摘Based on the branching fractions of J/ψ→VP from different experiments, we investigate the properties of the coupling constants of J/ψ→ VP decays using a model-dependent approach. We find that the octet coupling constant, gs, of strong interaction is about twice larger than that of the singlet coupling constant g1; the electromag- netic breaking parameters g_E^i are larger than the mass breaking parameters g_M^i, moreover, the three parameters of the electromagnetic effect are about equal, but the three parameters of the mass effect are obviously different and their uncertainties are also large; and the phase angle between strong and electromagnetic interactions is in the range of 700-80°. It deepens our understanding of the coupling constant of J/ψ→VP decays.
基金National Natural Science Foundation of China (10491303,10521003)Knowledge Innovation Project ofChinese Academy of Sciences (U-612 IHEP)
文摘The helicity amplitudes for Jψ→ ∧∧ and the relevant background decays are presented for measuring the ∧ decay parameter α ＋（∧ → pπ^＋） in J/ψ→ ∧∧. The Monte Carlo （MC） simulations based on the helicity amplitudes information are carried out. The likelihood fit method to determine the .∧ decay parameter is presented. Based on the MC generated sample, the sensitivity of the measurement for α＋ has been estimated, which shows that the J/ψ→ ∧∧ channel can be used to measure the .∧ decay parameter α＋（∧ → pπ^＋） well.
基金Supported by National Natural Science Foundation of China(11375128,11425525)Sino-German CRC 110 Symmetries and the Emergence of Structure in QCD(11261130311)
文摘We study the decay process of J/ψ→ e＋e-φ where the relatively clean electromagnetic （EM） transitions appear at leading order at tree level while the hadronic contributions only emerge via hadronic loop transitions. We include the low-lying scalar f0（980） and pseudoscalar η/η′ as the dominant contributions in the evaluation of the hadronic loop contributions. It is found that the hadronic effects are negligible compared with the EM contributions. The decay width of J/ψ→ e＋e-φis determined to be about 2.12 × 10^-6 keV if there is no other leading mechanism contributing. This result will be tested by the BESIII experiment with a large J/ψ data sample.
基金Supported by National Natural Science Foundation of China(11075044,11347107)Natural Science Foundation of Hebei Province(A2013209299)
文摘J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for J/ψproduction cross-section ratios RW/Be（x F） are presented and compared with the selected E866 experimental data with the cc remaining colored on its entire path in the medium. It is shown that the combination of the different nuclear effects accounts quite well for the observed J/ψ suppression in the experimental data. It is found that the J/ψ suppression on RW/Be（x F） from the initial state nuclear effects is more important than that induced by the energy loss of color octet cc in the large x F region. Whether the cc pair energy loss is linear or quadratic with the path length is not determined. The obtained cc pair energy loss per unit path length α = 2.78±0.81 Ge V/fm, which indicates that the heavy quark in cold nuclear matter can lose more energy compared to the outgoing light quark.
基金The project supported in part by the National Natural Science Foundation of Chinathe Doctoral Program Foundation of Institution of Higher Education of Chinathe Provincial Natural Science Foundation of Hebei
文摘With three theoretical models of nuclear effects on gluon distribution functions,the differentialcross sections and the total cross sections for associate production of J/ψ and γ with large P_T in high energyp-Fe collisions are calculated.
基金The project partly supported by the National Natural Science Foundation of China
文摘The absorption cross section σ<sub>abs</sub> of J/ψ produced in relativistic heavy ioncollisions is deduced based on the analysis of the absorption length through which theproduced J/ψ passes in the colliding nuclei.The obtained σ<sub>abs</sub> in A-A collisions is con-siderably higher than that in h-A processes.The reason for this different result is dis-cussed in terms of an analysis of the p<sub>T</sub>-dependence of the produced J/ψ.
