The pseudo-rapidity distribution of charged hadron multiplicity in Pb+Pb collisions at√s=2.76 TeV is studied by using Color Glass Condensate dynamics in the fixed coupling case.We fit the HERA experimental data with ...The pseudo-rapidity distribution of charged hadron multiplicity in Pb+Pb collisions at√s=2.76 TeV is studied by using Color Glass Condensate dynamics in the fixed coupling case.We fit the HERA experimental data with heavy parton mass effect to obtain saturation exponentλ=0.22.It is found that the charged hadron multiplicity can only describe after including heavy parton mass effect due to a large amount of heavy partons produced at large hadron collider(LHC)energy.The pomeron loop effect contribution to hadron production is also investigated.It shows that charged hadron multiplicity is underestimated by including the pomeron loop effect,which indicates that the pomeron loop effect may not exist at LHC energy.展开更多
The production of heavy-Havor quark c(c)and b(b)in pp collisions is described under perturbative quantum chromodynamics framework,the extrapolation from hadron-hadron up to nucleus-nucleus collisions is based on geome...The production of heavy-Havor quark c(c)and b(b)in pp collisions is described under perturbative quantum chromodynamics framework,the extrapolation from hadron-hadron up to nucleus-nucleus collisions is based on geometrical model by taking into account the nucleus shadowing effect.We simulate the heavy quark production,the decay to dilepton and effects of detection and analysis technique of the pairs,and predict the muon rate and the invariant mass spectrum of dimuons that could be detected in forward region in Pb-Pb collisions at large hadron collider energies.展开更多
An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive ...An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive structure function F2 measured in lepton-hadron scattering experiments at small values of Bjorken x. It is shown that the descriptions of the inclusive structure function F2 and longitudinal structure function FL are improved with the massive analytic structure function, which may imply the gluon saturation effect dominating the parton evolution process at HERA. The inclusion of the heavy quarks prevent the divergence of the lepton-hadron cross section, which plays a significant role in the description of the photoproduction region.展开更多
Within the framework of a factorization model, we study the behaviour of nuclear modification factor in Au Au collisions at RHIC and Pb-Pb collisions at LHC. We find that the nuclear modification factor is inversely p...Within the framework of a factorization model, we study the behaviour of nuclear modification factor in Au Au collisions at RHIC and Pb-Pb collisions at LHC. We find that the nuclear modification factor is inversely proportional to the radius of the quark-gluon plasma and is dominated by the surface emission of hard jets. We predict the nuclear modification factor R^LHC AA - 0.15 in central Pb-Pb collisions at LHC. The study shows that the factorization model can be used to describe the centrality dependence of nuclear modification factor of the high transverse momentum particles produced in heavy ion collisions at both RHIC and LHC.展开更多
We calculate the exclusive charmonium photo-production in the framework of color glass condensate.To obtain a good description of the vector meson production experimental data at HERA,we introduce a vector meson mass ...We calculate the exclusive charmonium photo-production in the framework of color glass condensate.To obtain a good description of the vector meson production experimental data at HERA,we introduce a vector meson mass dependent skewness factor into the skewness effect.Then we extend the skewness improved model to the LHC energies.The numerical results of our model are in good agreement with theΨ/Ψ and Ψ（2S）data in ultraperipheral proton-proton collisions at LHC,which show the significance of the vector meson mass-dependent skewness factor.A prediction of the exclusive charmonium photo-production in ultra-peripheral nucleus-nucleus collisions is performed since it can provide a good way to test the effectiveness of the color glass condensate.展开更多
A new concept,rigidity of pseudo-rapidity spectrum,is extended into the study of the multiplicity fluctuations in high energy nucleus-nucleus interactions.In using the novel method to analyze the data of l6O-Em at 14....A new concept,rigidity of pseudo-rapidity spectrum,is extended into the study of the multiplicity fluctuations in high energy nucleus-nucleus interactions.In using the novel method to analyze the data of l6O-Em at 14.6,60,and 200A GeV,and ^(32)S-Em at 200A GeV,it is found that the rigidity of pseudo-rapidity spectrum in the central domain of pseudo-rapidity might be a mixture of Poisson type and Wigner one.展开更多
We study the geometric scaling in the new combined data of the hadron-electron ring accelerator by using the Golec-Biernat-Wfisthoff model. It is found that the description of the data is improved once the high accura...We study the geometric scaling in the new combined data of the hadron-electron ring accelerator by using the Golec-Biernat-Wfisthoff model. It is found that the description of the data is improved once the high accurate data are used to determine the model parameters. The value of xo extracted from the fit is larger than the one from the previous study, which indicates a larger saturation scale in the new combined data. This makes more data located in the saturation region, and our approach is more reliable. This study lets the saturation model confront such high precision new combined data, and tests geometric scaling with those data. We demonstrate that the data lie on the same curve, which shows the geometric scaling in the new combined data. This outcome seems to support that the gluon saturation would be a relevant mechanism to dominate the parton evolution process in deep inelastic scattering, due to the fact that the geometric scaling results from the gluon saturation mechanism.展开更多
In heavy ion collision, the event plane is a key parameter defined as the plane composted by the impact parameter b and beam axis z, It is a crucial reference for various observables, which focus on the initial spatia...In heavy ion collision, the event plane is a key parameter defined as the plane composted by the impact parameter b and beam axis z, It is a crucial reference for various observables, which focus on the initial spatial anisotropy of the overlap region in heavy ion collision. We notice that in some recent heavy ion collision experiments, due to potentially inefficient or even the invalidity of experimental facilities, the reconstructed event plane, which is used in elliptic flow study, may be biased towards a non-flat distribution. In this study, we develop a toy model for fast estimation of the bias effect and its influence on the elliptic flow. The possible azimuthal bias of the detector is firstly studied by varying the part of its azimuthal information. We also study on the limit acceptance of the detector, which will be used to measure the particle of interest in an elliptic flow. The outcomes are presented by comparing the flow study results with or without the non-flat effect on the event plane.展开更多
We study the pseudo-rapidity distribution of hadron multiplicities of high energy Pb＋Pb collisions by using color glass condensate dynamics at LHC/ALICE in the fixed coupling case. It is found that after including th...We study the pseudo-rapidity distribution of hadron multiplicities of high energy Pb＋Pb collisions by using color glass condensate dynamics at LHC/ALICE in the fixed coupling case. It is found that after including the pomeron loop effects the charged hadron multiplicities at central rapidity are about 1500 for central Pb＋Pb collisions, which are significantly smaller than the saturation based calculations, ～ 1700 ÷ 2500 and compatible with that based on a study of multiplicities in the fragmentation region.展开更多
We study the rapidity losses in central heavy-ion collisions from ACS to RHIC encrgolcs with the mean rapidity determined from the projectile net-baryon distribution after collisions. The projectile net-baryon distrib...We study the rapidity losses in central heavy-ion collisions from ACS to RHIC encrgolcs with the mean rapidity determined from the projectile net-baryon distribution after collisions. The projectile net-baryon distribution in the full rapidity range is obtained by phenomenologically removing the target contribution at the forward rapidity region from the experimental net-baryon measurements and taking into account the projectile contribution in the backward rapidity region. Based on the full projectile net-baryon distributions, calculations show that the rapidity loss stops increasing from the SPS top energy to RHIC energies, indicating that baryon transport does not depend strongly on energy at high energies.展开更多
基金Supported by the Guizhou Normal University Doctoral Research Fund,Guizhou Science Foundation under Grant Nos JLKS[2009]15,J[2010]2145 and J[2013]2217the National Natural Science Foundation of China under Grant Nos 11020101060,IRG11221504,1005044 and 11264008the National Basic Research Program of China under Grant No 2013CB837803.
文摘The pseudo-rapidity distribution of charged hadron multiplicity in Pb+Pb collisions at√s=2.76 TeV is studied by using Color Glass Condensate dynamics in the fixed coupling case.We fit the HERA experimental data with heavy parton mass effect to obtain saturation exponentλ=0.22.It is found that the charged hadron multiplicity can only describe after including heavy parton mass effect due to a large amount of heavy partons produced at large hadron collider(LHC)energy.The pomeron loop effect contribution to hadron production is also investigated.It shows that charged hadron multiplicity is underestimated by including the pomeron loop effect,which indicates that the pomeron loop effect may not exist at LHC energy.
基金Supported by the National Natural Science Foundation of China under Grant No.19875019,and Center National de La Recherche Scientique of France.
文摘The production of heavy-Havor quark c(c)and b(b)in pp collisions is described under perturbative quantum chromodynamics framework,the extrapolation from hadron-hadron up to nucleus-nucleus collisions is based on geometrical model by taking into account the nucleus shadowing effect.We simulate the heavy quark production,the decay to dilepton and effects of detection and analysis technique of the pairs,and predict the muon rate and the invariant mass spectrum of dimuons that could be detected in forward region in Pb-Pb collisions at large hadron collider energies.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11305040,11375071 and 11447203the Education Department of Guizhou Province Innovation Talent Fund under Grant No[2015]5508+2 种基金the Education Department of Guizhou Province Innovation Team Fund under Grant No[2014]35the Guizhou Province Science Technology Foundation under Grant No[2015]2114the Guizhou Province Innovation Talent Team Fund under Grant No[2015]4015
文摘An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive structure function F2 measured in lepton-hadron scattering experiments at small values of Bjorken x. It is shown that the descriptions of the inclusive structure function F2 and longitudinal structure function FL are improved with the massive analytic structure function, which may imply the gluon saturation effect dominating the parton evolution process at HERA. The inclusion of the heavy quarks prevent the divergence of the lepton-hadron cross section, which plays a significant role in the description of the photoproduction region.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10575044 and 10635020, the National Key Basic Research Programme of China under Grant No 2008CB317106, and the Ministry of Education of China under Grant Nos 306022 and IRT0624.
文摘Within the framework of a factorization model, we study the behaviour of nuclear modification factor in Au Au collisions at RHIC and Pb-Pb collisions at LHC. We find that the nuclear modification factor is inversely proportional to the radius of the quark-gluon plasma and is dominated by the surface emission of hard jets. We predict the nuclear modification factor R^LHC AA - 0.15 in central Pb-Pb collisions at LHC. The study shows that the factorization model can be used to describe the centrality dependence of nuclear modification factor of the high transverse momentum particles produced in heavy ion collisions at both RHIC and LHC.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11765005,11305040,IRG11521064,11775097 and 11465021the Fund of Science and Technology Department of Guizhou Province under Grant No[2015]2114the Education Department of Guizhou Province under Grant No.KY[2017]004
文摘We calculate the exclusive charmonium photo-production in the framework of color glass condensate.To obtain a good description of the vector meson production experimental data at HERA,we introduce a vector meson mass dependent skewness factor into the skewness effect.Then we extend the skewness improved model to the LHC energies.The numerical results of our model are in good agreement with theΨ/Ψ and Ψ（2S）data in ultraperipheral proton-proton collisions at LHC,which show the significance of the vector meson mass-dependent skewness factor.A prediction of the exclusive charmonium photo-production in ultra-peripheral nucleus-nucleus collisions is performed since it can provide a good way to test the effectiveness of the color glass condensate.
基金Supported by the National Natural Science Foundation of China under Grant No.19475014the Natural Science Foundation of Hubei Province。
文摘A new concept,rigidity of pseudo-rapidity spectrum,is extended into the study of the multiplicity fluctuations in high energy nucleus-nucleus interactions.In using the novel method to analyze the data of l6O-Em at 14.6,60,and 200A GeV,and ^(32)S-Em at 200A GeV,it is found that the rigidity of pseudo-rapidity spectrum in the central domain of pseudo-rapidity might be a mixture of Poisson type and Wigner one.
基金Supported by the Doctoral Research Funds of Guizhou Normal University, the Guizhou Science Foundation under Grant No J[2013]2217, the National Natural Science Foundation of China under Grant Nos 11305040 and 11375071, and the Program of Introducing Talents of Discipline to Universities of China.
文摘We study the geometric scaling in the new combined data of the hadron-electron ring accelerator by using the Golec-Biernat-Wfisthoff model. It is found that the description of the data is improved once the high accurate data are used to determine the model parameters. The value of xo extracted from the fit is larger than the one from the previous study, which indicates a larger saturation scale in the new combined data. This makes more data located in the saturation region, and our approach is more reliable. This study lets the saturation model confront such high precision new combined data, and tests geometric scaling with those data. We demonstrate that the data lie on the same curve, which shows the geometric scaling in the new combined data. This outcome seems to support that the gluon saturation would be a relevant mechanism to dominate the parton evolution process in deep inelastic scattering, due to the fact that the geometric scaling results from the gluon saturation mechanism.
基金Supported by the Doctoral Research Fund of Guizhou Normal University, the National Natural Science Foundation of China under Grant Nos 11305040, 10635020, 10635020, 10975062, 11020101060 and 10875051, the Program of Introducing Talents of Discipline to Universities under Grant No B08033, and the China Scholarship Council under Grant No 2011677012.
文摘In heavy ion collision, the event plane is a key parameter defined as the plane composted by the impact parameter b and beam axis z, It is a crucial reference for various observables, which focus on the initial spatial anisotropy of the overlap region in heavy ion collision. We notice that in some recent heavy ion collision experiments, due to potentially inefficient or even the invalidity of experimental facilities, the reconstructed event plane, which is used in elliptic flow study, may be biased towards a non-flat distribution. In this study, we develop a toy model for fast estimation of the bias effect and its influence on the elliptic flow. The possible azimuthal bias of the detector is firstly studied by varying the part of its azimuthal information. We also study on the limit acceptance of the detector, which will be used to measure the particle of interest in an elliptic flow. The outcomes are presented by comparing the flow study results with or without the non-flat effect on the event plane.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10875051 and 10635020 （key project）, the Key Project of the Ministry of Education of China under Grant Nos 306022 and IRT0624, and the National Basic Research Program of China under Grant No 2008CB317106.
文摘We study the pseudo-rapidity distribution of hadron multiplicities of high energy Pb＋Pb collisions by using color glass condensate dynamics at LHC/ALICE in the fixed coupling case. It is found that after including the pomeron loop effects the charged hadron multiplicities at central rapidity are about 1500 for central Pb＋Pb collisions, which are significantly smaller than the saturation based calculations, ～ 1700 ÷ 2500 and compatible with that based on a study of multiplicities in the fragmentation region.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10975061, 10875051 and 10635020, the National Key Basic Research Program of China under Grant No 2008CB317106, and the Ministry of Education of China under Grant Nos 306022 and IRT0624.
文摘We study the rapidity losses in central heavy-ion collisions from ACS to RHIC encrgolcs with the mean rapidity determined from the projectile net-baryon distribution after collisions. The projectile net-baryon distribution in the full rapidity range is obtained by phenomenologically removing the target contribution at the forward rapidity region from the experimental net-baryon measurements and taking into account the projectile contribution in the backward rapidity region. Based on the full projectile net-baryon distributions, calculations show that the rapidity loss stops increasing from the SPS top energy to RHIC energies, indicating that baryon transport does not depend strongly on energy at high energies.
