The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation featu...The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation features in the SPS and RHIC energy regions are investigated by taking advantage of the gluon saturation model with geometric scaling. Predications are made for the net-baryon rapidity distributions, mean rapidity loss and gluon saturation features in central Pb ＋ Pb collisions at LHC.展开更多
We investigate the impact of so-called kinematic constraint on gluon evolution at small x.Implanting the constraint on the real emission term of the gluon ladder diagram,we obtain an integro-differential form of the B...We investigate the impact of so-called kinematic constraint on gluon evolution at small x.Implanting the constraint on the real emission term of the gluon ladder diagram,we obtain an integro-differential form of the Balitsky-Fadin-Kuraev-Lipatov(BFKL)equation.Later we solve the equation analytically using the method of characteristics.We sketch the Bjorken x and transverse momentum kt2 dependence of our solution of unintegrated gluon distributions f(x,kt2)in the kinematic constraint supplemented BFKL equation and contrasted the same with the original BFKL equation.Then we extract the integrated gluon density xg(x,Q2)from unintegrated gluon distributions f(x,kt2)and compared our theoretical prediction with that of global data fits,namely NNPDF3.1 sx and CT14.Finally we illustrate the phenomenological implication of our solution for unintegrated gluon distribution f(x,kT2)towards exploring high precision HERA DIS data by the theoretical prediction of proton structure functions(F2 and FL).展开更多
The Pomeron-nucleon coupling vertex is theoretically derived from the fundamental theory of strong interaction QCD. The empirical vertex βγ^μF1 （t） used commonly in diffractive processes with a coupling strength ...The Pomeron-nucleon coupling vertex is theoretically derived from the fundamental theory of strong interaction QCD. The empirical vertex βγ^μF1 （t） used commonly in diffractive processes with a coupling strength β = 6.0 GeV^-1 is initially obtained from QCD theoretically. Our study not only reproduces the Pomeron-nucleon coupling from QCD but also clearly shows the gluonlc origin and glueball nature of Pomeron, which is a longstanding puzzle. From this investigation, we claim that Pomeron can be regarded as a Reggeized tensor glueball ζ（2230） with quantum numbers of I^GJ^PC = 0＋2＋＋. Since the tensor glueball ζ（2230） lies on the Pomeron trajectory αp（t = Mζ^2） = 2, the longstanding puzzle that no physical particle lies on the Pomeron trajectory, αp（t） = 1.08 ＋ 0.20 GeV^-2 .t, seems to be solved.展开更多
The phenomenological non-relativistic quark model （NRQM） has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. Th...The phenomenological non-relativistic quark model （NRQM） has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential （OGEP）. An overall agreement is obtained with the experimental masses and decay widths.展开更多
This article gives the potential energy function of quark in the gluon field, derives the wave function of quark in stationary state and the quark confinement and asymptotic freedom, shows that a quark is composed of ...This article gives the potential energy function of quark in the gluon field, derives the wave function of quark in stationary state and the quark confinement and asymptotic freedom, shows that a quark is composed of two different color gluons, expounds the formation mechanism of the quark confinement and asymptotic freedom and the physical substance of “colors” of quark, and discusses the stability of hadrons in the end.展开更多
Recently, we reported an analysis of Proton structure function at small x based on Taylor approximated DGLAP equations assuming a plausible relationship between the singlet and the gluon distributions. In this paper, ...Recently, we reported an analysis of Proton structure function at small x based on Taylor approximated DGLAP equations assuming a plausible relationship between the singlet and the gluon distributions. In this paper, we report a generalised version of the previous work. A corresponding study of the suggested gluon distribution is also made.The present generalised version of the model for the structure function results in a wider x range of phenomenological validity than the earlier one. A comparison of both the models of the proton structure function and the gluon distribution is made with exact result as well as with the Froissart saturated models of Block, Durand and Mckay.展开更多
Using a new perturbative expansion method in Quantum Chromodynamics with a non-perturbative gluon background, the gluon propagator is calculated up to the one-loop level, and renormalized in the modified minimal subtr...Using a new perturbative expansion method in Quantum Chromodynamics with a non-perturbative gluon background, the gluon propagator is calculated up to the one-loop level, and renormalized in the modified minimal subtraction scheme. The resultant renormalization constants of the quantum gluon field and the gauge parameter receive a non-perturbative contribution coming from the gluon condensate <FF> besides the usual perturbative one, respectively.展开更多
Based on the quark-gluon structure of nucleon and the existence of Odderon in nucleon via gluon selfinteraction, the elastic scattering of pp at high energies is studied. Our theoretical predictions reproduce experime...Based on the quark-gluon structure of nucleon and the existence of Odderon in nucleon via gluon selfinteraction, the elastic scattering of pp at high energies is studied. Our theoretical predictions reproduce experimental data perfectly. The contributions from individual terms of quark-quark, gluon-gluon interactions, quark-gluon interference and the Odderon terms to total cross section are analyzed. In addition to the leading quark-quark contribution, the Odderon contribution is quite important. In particular, the Odderon plays an essential role in fitting to data. Therefore, We may claim that the high energy pp and pp elastic scattering may be good processes to search for the Odderon, the three Reggeized gluon bound states.展开更多
In this paper, the gluon propagator in Landau gauge has been studied on a lattice, including the quenched and the unquenched one. The small geometry size of lattice we use is 16^3 × 32, and the big one is 20^3 &#...In this paper, the gluon propagator in Landau gauge has been studied on a lattice, including the quenched and the unquenched one. The small geometry size of lattice we use is 16^3 × 32, and the big one is 20^3 × 64. For the quenched approximation, we fit the numerical results and give a little different fitting values. We also obtain unquenched effects by comparing the gluon propagator resulting from the quenched and unquenched configurations, for both the two-flavor and three-flavor cases. For the unquenched configurations, an obvious quark mass dependence has not been found in the small quark mass case, but is found in the three-flavor case when the quark mass is big.展开更多
An approximation method based on Regge behavior is presented. This new methodrelates the reduced cross section derivative and the structure function Regge behavior at low x.With the use of this approximation method, t...An approximation method based on Regge behavior is presented. This new methodrelates the reduced cross section derivative and the structure function Regge behavior at low x.With the use of this approximation method, the C and λ parameters are calcuiated from the HERAreduced cross section data taken at low-x. Also, we calculate the structure functions F_2(x, Q~2)even for low-x values, which have not been investigated. To test the validity of calculatedstructure functions, we find the gluon distribution function in the Leading order approximationbased on Regge behaviour of structure function and compare to the NLO QCD fit to H1 data and NLOparton distribution function.展开更多
Based on Dyson Schwinger Equations （DSEs） in the “rainbow” approximation, the dependence of quark effective mass on gluon propagator is investigated by use of three different phenomenological gluon propagators wit...Based on Dyson Schwinger Equations （DSEs） in the “rainbow” approximation, the dependence of quark effective mass on gluon propagator is investigated by use of three different phenomenological gluon propagators with two parameters, the strength parameter x and range parameter △. Our theoretical calculations for the quark effective mass Mf（p^2）, defined by the self-energy functions Af（p^2） and Bi（p%2） of the DSEs, show that the dynamically running quark effective mass is strongly dependent on gluon propagator. Therefore, because gluon propagator is completely unknown, the quark effective mass cannot be exactly determined theoretically.展开更多
Gluon propagator is investigated for pure Yang-Mills SU(3) gauge theory in field-strength approach. It isfound that instantohs provide a homogeneous solid-like medium background which generates finite nonzero momentum...Gluon propagator is investigated for pure Yang-Mills SU(3) gauge theory in field-strength approach. It isfound that instantohs provide a homogeneous solid-like medium background which generates finite nonzero momentumgluon propagator and gluon receives effective mass.展开更多
The transport properties of gluon in color space in a system of coexistence of both hadronic and QGP phases are investigated from the quantum transport equation of gluon.
We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and g...We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and gluon number fluctuations are included with x2/d.o.f. = 0.867, x2/d.o.f. = 0.923 and x2/d.o.f. = 0.878 for three different groups of experimental data. The values of diffusive coefficient subtracted from the fit are smaller than the ones obtained by considering only the gluon number fluctuations in our previous studies. The smaller values of the diffusive coefficient are in agreement with the theoretical predictions, where the gluon number fluctuations are suppressed by the running coupling which leads to smaller values of the diffusive coefficient.展开更多
Effects of Glauber gluons,which cause the elastic scattering process between different jets,are studied in the frame of soft-collinear effective theory.Glauber modes are added into the action before being integrated o...Effects of Glauber gluons,which cause the elastic scattering process between different jets,are studied in the frame of soft-collinear effective theory.Glauber modes are added into the action before being integrated out,which is helpful in studies on the Glauber couplings of collinear and soft particles.It is proved that the final state interactions cancel out for processes inclusive enough.So are interactions with the light cone coordinates x^(+)and x^(-)greater than those of the hard collision.The eikonalization of Glauber couplings of active particles and absorption of these couplings into soft and collinear Wilson lines are discussed,which is related to the loop level definitions of Glauber gluons here.The active-spectator coherence is proved to be harmless to the inclusive summation of spectator-spectator and spectator-soft Glauber exchanges.Based on this result,spectator-spectator and spectator-soft Glauber exchanges cancel out in the processes considered here.Graphic aspects of the cancellation are also discussed to explain relations between the graphic and operator level cancellation of Glauber gluons.展开更多
An approximate analytical form of the gluon distribution function from the derivative F2 proton structure function data at low-x assuming the Regge-like behavior of the gluon distribution function at this limit is pre...An approximate analytical form of the gluon distribution function from the derivative F2 proton structure function data at low-x assuming the Regge-like behavior of the gluon distribution function at this limit is presented. In this method, we calculate λ and C parameters for each low-x value at several Q^2 values using the scaling violation of the F2 proton structure function. For low-x, A is found to be independent of x within the experimental accuracy. We make use of the leading order Altarelli-Parisi （A-P） evolution equations in our analysis. To test the validity of our new determined gluon distribution functions, we compare them with the QCD parton distribution functions at low-x region.展开更多
We do a numerical calculation on the quark-loop effects on the dressed gluon propagator in the chiral limit. It is found that the quark-loop effects on the dressed gluon propagator are significant in solving the quark...We do a numerical calculation on the quark-loop effects on the dressed gluon propagator in the chiral limit. It is found that the quark-loop effects on the dressed gluon propagator are significant in solving the quark propagator in the rainbow approximation of the Dyson-Schwinger equation. The approach we used here is quite general and can also be used to calculate both the chemical potential and current quark mass dependence of the dressed gluon propagator.展开更多
In this paper, we study the top content of nucleon by analyzing azimuthal asymmetries in lepton-nucleon deep inelastic scattering(DIS), also we search for the Higgs boson associated production channel, tˉt H, at the ...In this paper, we study the top content of nucleon by analyzing azimuthal asymmetries in lepton-nucleon deep inelastic scattering(DIS), also we search for the Higgs boson associated production channel, tˉt H, at the large hadron-electron collider(LHe C) caused by boson-gluon fusion(BGF) contribution. We use azimuthal asymmetries inγ*Q cross sections in terms of helicity contributions to semi-inclusive deep inelastic scattering to investigate numerical properties of the cos 2? distribution. We conclude that measuring azimuthal distributions caused by intrinsic heavy quark production can directly probe heavy quarks inside nucleon. Moreover, in order to estimate the probability of producing the Higgs boson, we suggest another approach in the framework of calculating tˉt cross section in boson-gluon fusion mechanism. Finally, we can confirm that this observed massive particle is referred to Higgs boson produced by fermion loop.展开更多
This article proves that the number of gluons is conserved in strong interaction and non-conserved in weak interaction by extending the idea that the quark is composed of gluons to other particles. It explains why the...This article proves that the number of gluons is conserved in strong interaction and non-conserved in weak interaction by extending the idea that the quark is composed of gluons to other particles. It explains why the parity is non-conserved in weak interaction, why the fermions could be divided into the three generations, why the antiparticle of neutrino is itself and why the neutrino oscillation exists.展开更多
基金supported by National Natural Science Foundation of China(No.10975091)CCNU-QLPL Innovation Fund(QLPL2011P01)+1 种基金Excellent Youth Foundation of Hubei Scientific Committee(2006ABB036)Education Commission of Hubei Province of China(Z20081302)
文摘The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation features in the SPS and RHIC energy regions are investigated by taking advantage of the gluon saturation model with geometric scaling. Predications are made for the net-baryon rapidity distributions, mean rapidity loss and gluon saturation features in central Pb ＋ Pb collisions at LHC.
基金the Department of Science and Technology(DST),India(grant DST/INSPIRE Fellowship/2017/IF160770)the Council of Scientific and Industrial Research(CSIR),New Delhi(grant 09/796(0064)2016-EMR-I)respectively for the financial assistantship.
文摘We investigate the impact of so-called kinematic constraint on gluon evolution at small x.Implanting the constraint on the real emission term of the gluon ladder diagram,we obtain an integro-differential form of the Balitsky-Fadin-Kuraev-Lipatov(BFKL)equation.Later we solve the equation analytically using the method of characteristics.We sketch the Bjorken x and transverse momentum kt2 dependence of our solution of unintegrated gluon distributions f(x,kt2)in the kinematic constraint supplemented BFKL equation and contrasted the same with the original BFKL equation.Then we extract the integrated gluon density xg(x,Q2)from unintegrated gluon distributions f(x,kt2)and compared our theoretical prediction with that of global data fits,namely NNPDF3.1 sx and CT14.Finally we illustrate the phenomenological implication of our solution for unintegrated gluon distribution f(x,kT2)towards exploring high precision HERA DIS data by the theoretical prediction of proton structure functions(F2 and FL).
文摘The Pomeron-nucleon coupling vertex is theoretically derived from the fundamental theory of strong interaction QCD. The empirical vertex βγ^μF1 （t） used commonly in diffractive processes with a coupling strength β = 6.0 GeV^-1 is initially obtained from QCD theoretically. Our study not only reproduces the Pomeron-nucleon coupling from QCD but also clearly shows the gluonlc origin and glueball nature of Pomeron, which is a longstanding puzzle. From this investigation, we claim that Pomeron can be regarded as a Reggeized tensor glueball ζ（2230） with quantum numbers of I^GJ^PC = 0＋2＋＋. Since the tensor glueball ζ（2230） lies on the Pomeron trajectory αp（t = Mζ^2） = 2, the longstanding puzzle that no physical particle lies on the Pomeron trajectory, αp（t） = 1.08 ＋ 0.20 GeV^-2 .t, seems to be solved.
文摘The phenomenological non-relativistic quark model （NRQM） has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential （OGEP）. An overall agreement is obtained with the experimental masses and decay widths.
文摘This article gives the potential energy function of quark in the gluon field, derives the wave function of quark in stationary state and the quark confinement and asymptotic freedom, shows that a quark is composed of two different color gluons, expounds the formation mechanism of the quark confinement and asymptotic freedom and the physical substance of “colors” of quark, and discusses the stability of hadrons in the end.
基金the Rajiv Gandhi National Fellowship, New Delhi for financial support
文摘Recently, we reported an analysis of Proton structure function at small x based on Taylor approximated DGLAP equations assuming a plausible relationship between the singlet and the gluon distributions. In this paper, we report a generalised version of the previous work. A corresponding study of the suggested gluon distribution is also made.The present generalised version of the model for the structure function results in a wider x range of phenomenological validity than the earlier one. A comparison of both the models of the proton structure function and the gluon distribution is made with exact result as well as with the Froissart saturated models of Block, Durand and Mckay.
文摘Using a new perturbative expansion method in Quantum Chromodynamics with a non-perturbative gluon background, the gluon propagator is calculated up to the one-loop level, and renormalized in the modified minimal subtraction scheme. The resultant renormalization constants of the quantum gluon field and the gauge parameter receive a non-perturbative contribution coming from the gluon condensate <FF> besides the usual perturbative one, respectively.
基金The project supported in part by National Natural Science Foundation of China under Crant Nos.10565001 and 10647002the Natural Science Foundation of Guangxi Province under Grant Nos.0575020,0542042,and 0481030Guangxi University under Grant No.x051001
文摘Based on the quark-gluon structure of nucleon and the existence of Odderon in nucleon via gluon selfinteraction, the elastic scattering of pp at high energies is studied. Our theoretical predictions reproduce experimental data perfectly. The contributions from individual terms of quark-quark, gluon-gluon interactions, quark-gluon interference and the Odderon terms to total cross section are analyzed. In addition to the leading quark-quark contribution, the Odderon contribution is quite important. In particular, the Odderon plays an essential role in fitting to data. Therefore, We may claim that the high energy pp and pp elastic scattering may be good processes to search for the Odderon, the three Reggeized gluon bound states.
基金National Natural Science Foundation of China under Grant No.10575050the Research Fund for Doctoral Program of Higher Education under Grant No.20060284020
文摘In this paper, the gluon propagator in Landau gauge has been studied on a lattice, including the quenched and the unquenched one. The small geometry size of lattice we use is 16^3 × 32, and the big one is 20^3 × 64. For the quenched approximation, we fit the numerical results and give a little different fitting values. We also obtain unquenched effects by comparing the gluon propagator resulting from the quenched and unquenched configurations, for both the two-flavor and three-flavor cases. For the unquenched configurations, an obvious quark mass dependence has not been found in the small quark mass case, but is found in the three-flavor case when the quark mass is big.
文摘An approximation method based on Regge behavior is presented. This new methodrelates the reduced cross section derivative and the structure function Regge behavior at low x.With the use of this approximation method, the C and λ parameters are calcuiated from the HERAreduced cross section data taken at low-x. Also, we calculate the structure functions F_2(x, Q~2)even for low-x values, which have not been investigated. To test the validity of calculatedstructure functions, we find the gluon distribution function in the Leading order approximationbased on Regge behaviour of structure function and compare to the NLO QCD fit to H1 data and NLOparton distribution function.
文摘Based on Dyson Schwinger Equations （DSEs） in the “rainbow” approximation, the dependence of quark effective mass on gluon propagator is investigated by use of three different phenomenological gluon propagators with two parameters, the strength parameter x and range parameter △. Our theoretical calculations for the quark effective mass Mf（p^2）, defined by the self-energy functions Af（p^2） and Bi（p%2） of the DSEs, show that the dynamically running quark effective mass is strongly dependent on gluon propagator. Therefore, because gluon propagator is completely unknown, the quark effective mass cannot be exactly determined theoretically.
文摘Gluon propagator is investigated for pure Yang-Mills SU(3) gauge theory in field-strength approach. It isfound that instantohs provide a homogeneous solid-like medium background which generates finite nonzero momentumgluon propagator and gluon receives effective mass.
基金National Natural Science Foundation of China，the Foundation of Harbin Institute of Technology
文摘The transport properties of gluon in color space in a system of coexistence of both hadronic and QGP phases are investigated from the quantum transport equation of gluon.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11305040,11505036 and 11447203the Education Department of Guizhou Province Talent Fund under Grant No[2015]5508the Science and Technology Department of Guizhou Province Fund under Grant Nos[2015]2114 and [2014]7053
文摘We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and gluon number fluctuations are included with x2/d.o.f. = 0.867, x2/d.o.f. = 0.923 and x2/d.o.f. = 0.878 for three different groups of experimental data. The values of diffusive coefficient subtracted from the fit are smaller than the ones obtained by considering only the gluon number fluctuations in our previous studies. The smaller values of the diffusive coefficient are in agreement with the theoretical predictions, where the gluon number fluctuations are suppressed by the running coupling which leads to smaller values of the diffusive coefficient.
基金supported by The National Nature Science Foundation of China under Grant No.11805151The Scientific Research Foundation for the Doctoral Program of Xi’an University of Science and Technology under Grant No.6310116055+3 种基金The Scientific Fostering Foundation of Xi’an University of Science and Technology under Grant No.201709supported by The Department of Shanxi Province Natural Science Foundation of China under Grant No.2015JM1027supported by China Postdoctoral Foundation under Grant No.2015M581824,20161001International Postdoctoral Exchange Fellowship Program between JUELICH and OCPC。
文摘Effects of Glauber gluons,which cause the elastic scattering process between different jets,are studied in the frame of soft-collinear effective theory.Glauber modes are added into the action before being integrated out,which is helpful in studies on the Glauber couplings of collinear and soft particles.It is proved that the final state interactions cancel out for processes inclusive enough.So are interactions with the light cone coordinates x^(+)and x^(-)greater than those of the hard collision.The eikonalization of Glauber couplings of active particles and absorption of these couplings into soft and collinear Wilson lines are discussed,which is related to the loop level definitions of Glauber gluons here.The active-spectator coherence is proved to be harmless to the inclusive summation of spectator-spectator and spectator-soft Glauber exchanges.Based on this result,spectator-spectator and spectator-soft Glauber exchanges cancel out in the processes considered here.Graphic aspects of the cancellation are also discussed to explain relations between the graphic and operator level cancellation of Glauber gluons.
文摘An approximate analytical form of the gluon distribution function from the derivative F2 proton structure function data at low-x assuming the Regge-like behavior of the gluon distribution function at this limit is presented. In this method, we calculate λ and C parameters for each low-x value at several Q^2 values using the scaling violation of the F2 proton structure function. For low-x, A is found to be independent of x within the experimental accuracy. We make use of the leading order Altarelli-Parisi （A-P） evolution equations in our analysis. To test the validity of our new determined gluon distribution functions, we compare them with the QCD parton distribution functions at low-x region.
基金The project supported in part by National Natural Science Foundation of China under Crant No.10575050the Research Fund for the Doctoral Program of Higher Education under Grant No.20060284020
文摘We do a numerical calculation on the quark-loop effects on the dressed gluon propagator in the chiral limit. It is found that the quark-loop effects on the dressed gluon propagator are significant in solving the quark propagator in the rainbow approximation of the Dyson-Schwinger equation. The approach we used here is quite general and can also be used to calculate both the chemical potential and current quark mass dependence of the dressed gluon propagator.
文摘In this paper, we study the top content of nucleon by analyzing azimuthal asymmetries in lepton-nucleon deep inelastic scattering(DIS), also we search for the Higgs boson associated production channel, tˉt H, at the large hadron-electron collider(LHe C) caused by boson-gluon fusion(BGF) contribution. We use azimuthal asymmetries inγ*Q cross sections in terms of helicity contributions to semi-inclusive deep inelastic scattering to investigate numerical properties of the cos 2? distribution. We conclude that measuring azimuthal distributions caused by intrinsic heavy quark production can directly probe heavy quarks inside nucleon. Moreover, in order to estimate the probability of producing the Higgs boson, we suggest another approach in the framework of calculating tˉt cross section in boson-gluon fusion mechanism. Finally, we can confirm that this observed massive particle is referred to Higgs boson produced by fermion loop.
文摘This article proves that the number of gluons is conserved in strong interaction and non-conserved in weak interaction by extending the idea that the quark is composed of gluons to other particles. It explains why the parity is non-conserved in weak interaction, why the fermions could be divided into the three generations, why the antiparticle of neutrino is itself and why the neutrino oscillation exists.
