The axion-like particle(ALP)is one kind of the best-motivated new particles.We consider its production from the pseudoscalar mesonic decays M→M′a,with M being a pseudoscalar meson B or K.The upper limits on the flav...The axion-like particle(ALP)is one kind of the best-motivated new particles.We consider its production from the pseudoscalar mesonic decays M→M′a,with M being a pseudoscalar meson B or K.The upper limits on the flavor-conserving ALP–quark coupling parameter guare obtained by assuming the ALP to be an invisible particle.We find that the most severe constraint on gucomes from the decay K^(+)→π^(+)vv for 0.05 Ge V≤M_(a)≤0.35 Ge V,while the decays B^(+,0)→K^(+,0)vvand B^(+,0)→π^(+,0)υvcan also generate significant constraints.展开更多
We investigate mesonic condensation in isospin matter under rotation.Using the two-flavor NJL effective model in the presence of global rotation,we demonstrate two important effects of rotation on its phase structure:...We investigate mesonic condensation in isospin matter under rotation.Using the two-flavor NJL effective model in the presence of global rotation,we demonstrate two important effects of rotation on its phase structure:a rotational suppression of the scalar-channel condensates,in particular,the pion condensation region;and a rotational enhancement of the rho condensation region with vector-channel condensate.A new phase diagram for isospin matter under rotation is mapped out on the ω−μI plane where the three distinct phases,corresponding to the σ,π,ρ-dominated regions,respectively,are separated by a second-order line at low isospin chemical potential as well as a first-order line at high rotation and are further connected at a tri-critical point.展开更多
We investigate the e^(+)e^(-)→∑∑^(-) and e^(+)e^(-)→Λ∑^(-)reactions within the extended vector meson dominance model.In addition to the ground state mesons ρ and ω,we consider the contributions of the excited ...We investigate the e^(+)e^(-)→∑∑^(-) and e^(+)e^(-)→Λ∑^(-)reactions within the extended vector meson dominance model.In addition to the ground state mesons ρ and ω,we consider the contributions of the excited states ρ(3D),ω(3D),φ(3D),and ρ(2850).It is found that the current experimental data on the Σ electromagnetic form factors in timelike region can be well reproduced.The Φ(3D) resonance is essential to the near thresholdenhancement of the cross-section for the e^(+)e^(-)→∑∑^(-) reaction. Furthermore, in the e^(+)e^(-)→Λ∑^(-) reaction, theρ(3D) is important to get a good fit for the experimental results.展开更多
We argue that the hypothesis that positive-parity charm meson resonances exhibit a compact tetraquark structure has some clear tension with recent lattice results for the S-waveπD system for an SU(3)flavor symmetric ...We argue that the hypothesis that positive-parity charm meson resonances exhibit a compact tetraquark structure has some clear tension with recent lattice results for the S-waveπD system for an SU(3)flavor symmetric setting.In particular,we show that such a diquark–anti-diquark tetraquark scenario would call for the presence of a state in the flavor[15]representation,not seen in the lattice analysis.Moreover,we show that analogous lattice data in the axial-vector channel are even more sensitive to the internal structure of these very interesting states.展开更多
As an approximate Goldstone boson with zero quantum number and zero standard model charge,the long-lived η meson exhibits the decay processes that offer a unique opportunity to explore physics beyond the standard mod...As an approximate Goldstone boson with zero quantum number and zero standard model charge,the long-lived η meson exhibits the decay processes that offer a unique opportunity to explore physics beyond the standard model and new sources of charge parity violation.Further,they facilitate the testing of the low-energy quantum chromodynamics theory and measurement of the fundamental parameters of light quarks.To pursue these goals,we propose a plan to construct a super ηfactory at HIAF high-energy terminal or at CiADS after its energy upgrade.The high-intensity proton beam at HIAF enables the production of many η samples,exceeding 1013events per year during the first stage,utilizing multiple layers of thin targets composed of light nuclei.This paper presents the physics goals,the first-version conceptual design of the spectrometer,and preliminary simulation results.展开更多
To investigate the possible geometric structure of the proton,an improved stringy proton model is constructed beyond the smallest distance approximation and treats the constituent(up and down)quark-initiated gluon tub...To investigate the possible geometric structure of the proton,an improved stringy proton model is constructed beyond the smallest distance approximation and treats the constituent(up and down)quark-initiated gluon tubes separately,where the constituent quarks are connected by gluon tubes which merge at the Fermat point of the quark triangle.The exclusive diffractive vector meson production process in electron-proton deep inelastic scattering is used to test the stringy structure of the proton.We calculate the coherent and incoherent differential cross sections of the exclusive diffractive J/Ψphotoproduction in the framework of Color Glass Condensate.The results show that our calculations are in good agreement with HERA data.Especially,our results give a better description of the HERA data at small t as compared to the ones from the hot spot model where the constituent quarks are independently distributed in the proton.Meanwhile,the radius of the proton resulting from the improved stringy proton model is coincident with the one from fitting to the data from GlueX Collaboration at Jefferson Lab,which indicates that the predictive power of the stringy proton model is significantly improved once it goes beyond the smallest distance approximation and treats the constituent quarks separately,instead of using the same profile for the up and down quarks initiated gluon tubes.Moreover,we assume that the transverse shape of the gluon tube satisfies Gaussian distribution,and explore the distribution width of the individual gluon tubes.We find an interesting result that the up quark-initiated gluon tube seems to have a larger distribution width than the down quarkinitiated gluon tube,which is favored by the HERA data.展开更多
Recently,taking advantage of the large volume of data collected by the detector,the BESIII International Collaboration successfully measured the decay constant for the charmed meson D+-with the best precision to date....Recently,taking advantage of the large volume of data collected by the detector,the BESIII International Collaboration successfully measured the decay constant for the charmed meson D+-with the best precision to date.As an unstable particle,the charmed meson D+can decay via many different pathways,each with a different possibility.In the process of the decay,its constituent heavy charm quark can transform itself into other particles,thereby diverting the subsequent decay cascade into a different pathway or a different decay network.展开更多
The X(3872)is theoretically predicted to have a spin-0 partner state denoted as X_(0).Assuming the X_(0)as a molecular bound state,we calculate the decay widths of X_(0)→VV and X_(0)→PP(V and P stand for light vecto...The X(3872)is theoretically predicted to have a spin-0 partner state denoted as X_(0).Assuming the X_(0)as a molecular bound state,we calculate the decay widths of X_(0)→VV and X_(0)→PP(V and P stand for light vector and pseudoscalar mesons,respectively)via intermediate charmed meson loops.Three different configurations of the X_(0),i.e.,pure neutral components(θ=0),isospin singlet(θ=π/4),and pure charged components(θ=π/2),are investigated.Within a commonly accepted range of the model parameterα,the predicted decay widths of X_(0)→VV are on the order of a few hundred keV,while the decay widths of X_(0)→PP can reach several MeV.The X_(0)→ρρandππhave larger decay rates.The relative width ratios between the channels are nearly model-independent.Moreover,among those channels only with isovector or isoscalar mesons,the relevant ratios are also independent of the phase angle.The predicted ratios are helpful for searching the X_(0)in the future experiments at BESIII and Belle II.展开更多
In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius...In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.展开更多
The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productio...The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints.展开更多
Observation of unexpectedly large global spin alignment of φ vector mesons in non-central heavy-ion collisions by STAR experiment may reveal the non-perturbative nature of quark interaction in hot matter through fluc...Observation of unexpectedly large global spin alignment of φ vector mesons in non-central heavy-ion collisions by STAR experiment may reveal the non-perturbative nature of quark interaction in hot matter through fluctuating strong force field with short correlation length.展开更多
Promising high strangeness dibaryons are studied by the extended quark delocalization and color screeningmodel. It is shown that besides H particle and di-Ω, there might be other dibaryon candidates worth to be searc...Promising high strangeness dibaryons are studied by the extended quark delocalization and color screeningmodel. It is shown that besides H particle and di-Ω, there might be other dibaryon candidates worth to be searchedexperimentally such as NΩ.展开更多
We survey contemporary studies of hadrons and strongly interacting quarks using QCD's Dyson-Schwinger equations, addressing the following aspects: confinement and dynamical chiral symmetry breaking; the hadron spe...We survey contemporary studies of hadrons and strongly interacting quarks using QCD's Dyson-Schwinger equations, addressing the following aspects: confinement and dynamical chiral symmetry breaking; the hadron spectrum; hadron elastic and transition form factors, from small-to large-Q2; parton distribution functions; the physics of hadrons containing one or more heavy quarks; and properties of the quark gluon plasma.展开更多
We in terms of optical theorem estimate the lifetime of B<SUB>c</SUB> meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and...We in terms of optical theorem estimate the lifetime of B<SUB>c</SUB> meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and D mesons. In the estimation, we find that the bound-state effects are important, and take them into account carefully in the framework which attributes the effects to the effective masses of the decay heavy quarks in the inclusive processes. We also find that to B<SUB>c</SUB> lifetime the penguin contribution is enhanced due to possible interference between the penguin and the 'tree part' c<SUB>1</SUB>O<SUB>1</SUB> + c<SUB>2</SUB>O<SUB>2</SUB>.展开更多
In this article, we assume that the （0^＋,1^＋） strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then w...In this article, we assume that the （0^＋,1^＋） strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then we study the radiative decays Bs0→Bs^＊γ, Bs1→Bsγ, Bs1→Bs^＊γ, and Bs1→Bs0γ, and observe that the widths are rather narrow. We can search for the （0^＋, 1^＋） strange-bottom mesons in the invariant Bsπ^0 and Bs^＊π^0 mass distributions in the strong decays or in the invariant Bs^＊γ, and Bsγ mass distributions in the radiative decays.展开更多
Based on a semi-classical expansion for quantum chromodynamics in the instanton liquid background, the correlation function of the 0^＋＋ scalar glueball current is calculated. Besides the pure classical and quantum c...Based on a semi-classical expansion for quantum chromodynamics in the instanton liquid background, the correlation function of the 0^＋＋ scalar glueball current is calculated. Besides the pure classical and quantum contributions, the contributions arising from the interactions between the classical instanton fields and quantum gluon ones come into play. It turns out that the latter contributions have a great role not only in making the stabilization of the subtracted and unsubtracted Laplace-transformed QCD sum rules for 0^＋＋ scalar glueball, but also in bring back the consistency between the two related sum rules, or equivalently between the QCD asymptotic expression and low energy theorem. The result for the scalar glueball mass is predicted to be mG= 1.35 GeV.展开更多
Within the framework of the low-energy effective theory arising from the instanton vacuum model of QCD, the longitudinal virtual photon light-cone wavefunction, ФγⅡ（u, P^2）, corresponding to the nonlocal quark-an...Within the framework of the low-energy effective theory arising from the instanton vacuum model of QCD, the longitudinal virtual photon light-cone wavefunction, ФγⅡ（u, P^2）, corresponding to the nonlocal quark-antiquark vector current is calculated at the low-energy scale. The coupling constant, Fγ（P^2） or equivalently fγ（P^2）, of the quark antiquark vector current to the virtual photon state is also obtained by imposing the normalization condition to the photon wavefunction. The behaviour of the coupling constant as well as the obtained photon wavefunction is discussed.展开更多
This paper discusses the masses and possible members of 2^1S0 and 2^3S1 meson multiplets in the framework of meson-meson mixing and Regge phenomenology. For the 2^1S0 meson nonet, K＊ （1460） may be the observed stat...This paper discusses the masses and possible members of 2^1S0 and 2^3S1 meson multiplets in the framework of meson-meson mixing and Regge phenomenology. For the 2^1S0 meson nonet, K＊ （1460） may be the observed state of the 2^1S0 isodoublet with a mass of 1400 MeV and the mass of w（1420） is 1412 MeV. For the 2^3S1 meson nonet, K＊（1410） seems too light to be the 2^3S1 ns member. The fact that the agreement between the present findings and those given by experiments and other different approaches is satisfactory implies that the assignments in this paper may be reasonable.展开更多
The mid-rapidity transverse momentum spectra of charmed mesons in Pb–Pb and pp(p)collisions are analyzed using the Tsallis–Pareto distribution derived from non-extensive statistics.We provide uniform descriptions of...The mid-rapidity transverse momentum spectra of charmed mesons in Pb–Pb and pp(p)collisions are analyzed using the Tsallis–Pareto distribution derived from non-extensive statistics.We provide uniform descriptions of both small and large systems over a wide range of collision energies and hadron transverse momenta.By establishing the relationship between the event multiplicity and Tsallis parameters,we observe that there is a signifi-cant linear relationship between the thermal temperature and Tsallis q parameter in Pb–Pb collisions at √sNN=2.76 TeV and 5.02 TeV.Further,the slope of the T–(q-1)parameter plot is positively correlated with the hadron mass.In addition,charmed mesons have a higher thermal temperature than light hadrons at the same q-1,indicat-ing that the charm flavor requires a higher temperature to reach the same degree of non-extensivity as light flavors in heavy-ion collisions.The same fit is applied to the trans-verse momentum spectra of charmed mesons in pp(p)collisions over a large energy range using the Tsallis–Pareto distribution.It is found that the thermal temperature increases with system energy,whereas the q parameter becomes saturated at the pp(p)limit,q-1=0.142±0.010.In addition,the results of most peripheral Pb–Pb collisions are found to approach the pp(p)limit,which suggests that more peripheral heavy-ion collisions are less affected by the medium and more similar to pp(p)collisions.展开更多
基金partially supported by the National Natural Science Foundation of China under Grant Nos.11875157 and 12147214。
文摘The axion-like particle(ALP)is one kind of the best-motivated new particles.We consider its production from the pseudoscalar mesonic decays M→M′a,with M being a pseudoscalar meson B or K.The upper limits on the flavor-conserving ALP–quark coupling parameter guare obtained by assuming the ALP to be an invisible particle.We find that the most severe constraint on gucomes from the decay K^(+)→π^(+)vv for 0.05 Ge V≤M_(a)≤0.35 Ge V,while the decays B^(+,0)→K^(+,0)vvand B^(+,0)→π^(+,0)υvcan also generate significant constraints.
基金supported by the Ministry of Science and Technology of China (MSTC) under the"973"(2015CB856904(4))by NSFC (11735007)+3 种基金by NSF (PHY-1352368,PHY-1913729)by the U.S. Department of Energy,Office of Science,Office of Nuclear Physics,within the framework of the Beam Energy Scan Theory (BEST)Topical Collaborationpartial support from the China Scholarship Councilthe Institute for Advanced Study of Indiana University for partial support.
文摘We investigate mesonic condensation in isospin matter under rotation.Using the two-flavor NJL effective model in the presence of global rotation,we demonstrate two important effects of rotation on its phase structure:a rotational suppression of the scalar-channel condensates,in particular,the pion condensation region;and a rotational enhancement of the rho condensation region with vector-channel condensate.A new phase diagram for isospin matter under rotation is mapped out on the ω−μI plane where the three distinct phases,corresponding to the σ,π,ρ-dominated regions,respectively,are separated by a second-order line at low isospin chemical potential as well as a first-order line at high rotation and are further connected at a tri-critical point.
基金partly supported by the National Key R&D Program of China(Grant No.2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12435007,12361141819,12275185,and 12335002)。
文摘We investigate the e^(+)e^(-)→∑∑^(-) and e^(+)e^(-)→Λ∑^(-)reactions within the extended vector meson dominance model.In addition to the ground state mesons ρ and ω,we consider the contributions of the excited states ρ(3D),ω(3D),φ(3D),and ρ(2850).It is found that the current experimental data on the Σ electromagnetic form factors in timelike region can be well reproduced.The Φ(3D) resonance is essential to the near thresholdenhancement of the cross-section for the e^(+)e^(-)→∑∑^(-) reaction. Furthermore, in the e^(+)e^(-)→Λ∑^(-) reaction, theρ(3D) is important to get a good fit for the experimental results.
基金supported in part by the National Natural Science Foundation of China(NSFC)under Grants Nos.12125507,12361141819,and 12047503the National Key R&D Program of China under Grant No.2023YFA1606703+1 种基金the Chinese Academy of Sciences(CAS)under Grants No.YSBR-101the CAS President’s International Fellowship Initiative(PIFI)under Grant No.2025PD0087 for the partial support。
文摘We argue that the hypothesis that positive-parity charm meson resonances exhibit a compact tetraquark structure has some clear tension with recent lattice results for the S-waveπD system for an SU(3)flavor symmetric setting.In particular,we show that such a diquark–anti-diquark tetraquark scenario would call for the presence of a state in the flavor[15]representation,not seen in the lattice analysis.Moreover,we show that analogous lattice data in the axial-vector channel are even more sensitive to the internal structure of these very interesting states.
基金supported by the National Natural Science Foundation of China(Nos.12222512 and 12005266)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34030300).
文摘As an approximate Goldstone boson with zero quantum number and zero standard model charge,the long-lived η meson exhibits the decay processes that offer a unique opportunity to explore physics beyond the standard model and new sources of charge parity violation.Further,they facilitate the testing of the low-energy quantum chromodynamics theory and measurement of the fundamental parameters of light quarks.To pursue these goals,we propose a plan to construct a super ηfactory at HIAF high-energy terminal or at CiADS after its energy upgrade.The high-intensity proton beam at HIAF enables the production of many η samples,exceeding 1013events per year during the first stage,utilizing multiple layers of thin targets composed of light nuclei.This paper presents the physics goals,the first-version conceptual design of the spectrometer,and preliminary simulation results.
基金supported by the National Natural Science Foundation of China under Grant No.12165004 and and Key Grant No.12061141008the Basic and Applied Basic Research Project of Guangzhou Science and Technology Bureau under Grant No.202201011324+1 种基金the Education Department of Guizhou Province under Grant No.QJJ[2022]016the National Key Research and Development Program of China under Grant Nos.2024YFA1610800 and 2022YFA1602103。
文摘To investigate the possible geometric structure of the proton,an improved stringy proton model is constructed beyond the smallest distance approximation and treats the constituent(up and down)quark-initiated gluon tubes separately,where the constituent quarks are connected by gluon tubes which merge at the Fermat point of the quark triangle.The exclusive diffractive vector meson production process in electron-proton deep inelastic scattering is used to test the stringy structure of the proton.We calculate the coherent and incoherent differential cross sections of the exclusive diffractive J/Ψphotoproduction in the framework of Color Glass Condensate.The results show that our calculations are in good agreement with HERA data.Especially,our results give a better description of the HERA data at small t as compared to the ones from the hot spot model where the constituent quarks are independently distributed in the proton.Meanwhile,the radius of the proton resulting from the improved stringy proton model is coincident with the one from fitting to the data from GlueX Collaboration at Jefferson Lab,which indicates that the predictive power of the stringy proton model is significantly improved once it goes beyond the smallest distance approximation and treats the constituent quarks separately,instead of using the same profile for the up and down quarks initiated gluon tubes.Moreover,we assume that the transverse shape of the gluon tube satisfies Gaussian distribution,and explore the distribution width of the individual gluon tubes.We find an interesting result that the up quark-initiated gluon tube seems to have a larger distribution width than the down quarkinitiated gluon tube,which is favored by the HERA data.
文摘Recently,taking advantage of the large volume of data collected by the detector,the BESIII International Collaboration successfully measured the decay constant for the charmed meson D+-with the best precision to date.As an unstable particle,the charmed meson D+can decay via many different pathways,each with a different possibility.In the process of the decay,its constituent heavy charm quark can transform itself into other particles,thereby diverting the subsequent decay cascade into a different pathway or a different decay network.
基金supported by the National Natural Science Foundation of China(Grant Nos.12475081 and 12105153)the Natural Science Foundation of Shandong Province(Grant Nos.ZR2021MA082 and ZR2022ZD26)Taishan Scholar Project of Shandong Province(Grant No.tsqn202103062).
文摘The X(3872)is theoretically predicted to have a spin-0 partner state denoted as X_(0).Assuming the X_(0)as a molecular bound state,we calculate the decay widths of X_(0)→VV and X_(0)→PP(V and P stand for light vector and pseudoscalar mesons,respectively)via intermediate charmed meson loops.Three different configurations of the X_(0),i.e.,pure neutral components(θ=0),isospin singlet(θ=π/4),and pure charged components(θ=π/2),are investigated.Within a commonly accepted range of the model parameterα,the predicted decay widths of X_(0)→VV are on the order of a few hundred keV,while the decay widths of X_(0)→PP can reach several MeV.The X_(0)→ρρandππhave larger decay rates.The relative width ratios between the channels are nearly model-independent.Moreover,among those channels only with isovector or isoscalar mesons,the relevant ratios are also independent of the phase angle.The predicted ratios are helpful for searching the X_(0)in the future experiments at BESIII and Belle II.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875122,12175025,and 12147102)Tongling University Talent Program(Grant No.R23100)。
文摘In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1611004)the National Natural Science Foundation of China(Grant Nos.12175117,12475084,and 12321005)the Shandong Province Natural Science Foundation(Grant Nos.ZFJH202303 and ZR2024MA012)。
文摘The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints.
文摘Observation of unexpectedly large global spin alignment of φ vector mesons in non-central heavy-ion collisions by STAR experiment may reveal the non-perturbative nature of quark interaction in hot matter through fluctuating strong force field with short correlation length.
基金The project supported by National Natural Science Foundation of China under Grant No.90103018
文摘Promising high strangeness dibaryons are studied by the extended quark delocalization and color screeningmodel. It is shown that besides H particle and di-Ω, there might be other dibaryon candidates worth to be searchedexperimentally such as NΩ.
基金Supported by the Project of Knowledge Innovation Program of the Chinese Academy of Sciences under Grant No. KJCX2.YW.W10Sistema Nacional de Investigadores+8 种基金CONACyT grant 46614-Fthe University of Adelaide and the Australian Research Council through Grant No. FL0992247Coordinación de la Investigación Científica (UMSNH) under Grant 4.10the U. S. Department of Energy, Office of Nuclear Physics, Grant No. DE-AC02-06CH11357Fundao de Amparo Pesquisa do Estado de So Paulo, Grant Nos. 2009/51296-1 and 2010/05772-3the National Natural Science Foundation of China under Grant Nos. 10425521, 10675002, 10705002, 10935001 and 11075052the Major State Basic Research Development Program, under Grant No. G2007CB815000Forschungszentrum Jülich GmbHthe U. S.National Science Foundation under Grant No. PHY-0903991, in conjunction with a CONACyT Mexico-USA Collaboration Grant
文摘We survey contemporary studies of hadrons and strongly interacting quarks using QCD's Dyson-Schwinger equations, addressing the following aspects: confinement and dynamical chiral symmetry breaking; the hadron spectrum; hadron elastic and transition form factors, from small-to large-Q2; parton distribution functions; the physics of hadrons containing one or more heavy quarks; and properties of the quark gluon plasma.
文摘We in terms of optical theorem estimate the lifetime of B<SUB>c</SUB> meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and D mesons. In the estimation, we find that the bound-state effects are important, and take them into account carefully in the framework which attributes the effects to the effective masses of the decay heavy quarks in the inclusive processes. We also find that to B<SUB>c</SUB> lifetime the penguin contribution is enhanced due to possible interference between the penguin and the 'tree part' c<SUB>1</SUB>O<SUB>1</SUB> + c<SUB>2</SUB>O<SUB>2</SUB>.
基金Supported by National Natural Science Foundation of China under Grant No.10775051Program for New Century Excellent Talents in Universities under Grant No.NCET-07-0282
文摘In this article, we assume that the （0^＋,1^＋） strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then we study the radiative decays Bs0→Bs^＊γ, Bs1→Bsγ, Bs1→Bs^＊γ, and Bs1→Bs0γ, and observe that the widths are rather narrow. We can search for the （0^＋, 1^＋） strange-bottom mesons in the invariant Bsπ^0 and Bs^＊π^0 mass distributions in the strong decays or in the invariant Bs^＊γ, and Bsγ mass distributions in the radiative decays.
基金Supported by the National Natural Science Foundation of China under Grant No 10075036, the BEPC National Laboratory Project of Research and Development, and the BES Collaboration Research Foundation.
文摘Based on a semi-classical expansion for quantum chromodynamics in the instanton liquid background, the correlation function of the 0^＋＋ scalar glueball current is calculated. Besides the pure classical and quantum contributions, the contributions arising from the interactions between the classical instanton fields and quantum gluon ones come into play. It turns out that the latter contributions have a great role not only in making the stabilization of the subtracted and unsubtracted Laplace-transformed QCD sum rules for 0^＋＋ scalar glueball, but also in bring back the consistency between the two related sum rules, or equivalently between the QCD asymptotic expression and low energy theorem. The result for the scalar glueball mass is predicted to be mG= 1.35 GeV.
基金Supported by the National Natural Science Foundation of China under Grant No 10075036, the BEPC National Laboratory Project R＆D and BES Collaboration Research Foundation.
文摘Within the framework of the low-energy effective theory arising from the instanton vacuum model of QCD, the longitudinal virtual photon light-cone wavefunction, ФγⅡ（u, P^2）, corresponding to the nonlocal quark-antiquark vector current is calculated at the low-energy scale. The coupling constant, Fγ（P^2） or equivalently fγ（P^2）, of the quark antiquark vector current to the virtual photon state is also obtained by imposing the normalization condition to the photon wavefunction. The behaviour of the coupling constant as well as the obtained photon wavefunction is discussed.
文摘This paper discusses the masses and possible members of 2^1S0 and 2^3S1 meson multiplets in the framework of meson-meson mixing and Regge phenomenology. For the 2^1S0 meson nonet, K＊ （1460） may be the observed state of the 2^1S0 isodoublet with a mass of 1400 MeV and the mass of w（1420） is 1412 MeV. For the 2^3S1 meson nonet, K＊（1410） seems too light to be the 2^3S1 ns member. The fact that the agreement between the present findings and those given by experiments and other different approaches is satisfactory implies that the assignments in this paper may be reasonable.
基金This is supported by the National Key Research and Development Program of China(Nos.2018YFE0205200 and 2018YFE0104700)National Natural Science Foundation of China(Nos.11890712 and 12061141008)+1 种基金Strategic Priority Research Program of CAS(No.XDB34030000)Anhui Provincial Natural Science Foundation(No.1808085J02).
文摘The mid-rapidity transverse momentum spectra of charmed mesons in Pb–Pb and pp(p)collisions are analyzed using the Tsallis–Pareto distribution derived from non-extensive statistics.We provide uniform descriptions of both small and large systems over a wide range of collision energies and hadron transverse momenta.By establishing the relationship between the event multiplicity and Tsallis parameters,we observe that there is a signifi-cant linear relationship between the thermal temperature and Tsallis q parameter in Pb–Pb collisions at √sNN=2.76 TeV and 5.02 TeV.Further,the slope of the T–(q-1)parameter plot is positively correlated with the hadron mass.In addition,charmed mesons have a higher thermal temperature than light hadrons at the same q-1,indicat-ing that the charm flavor requires a higher temperature to reach the same degree of non-extensivity as light flavors in heavy-ion collisions.The same fit is applied to the trans-verse momentum spectra of charmed mesons in pp(p)collisions over a large energy range using the Tsallis–Pareto distribution.It is found that the thermal temperature increases with system energy,whereas the q parameter becomes saturated at the pp(p)limit,q-1=0.142±0.010.In addition,the results of most peripheral Pb–Pb collisions are found to approach the pp(p)limit,which suggests that more peripheral heavy-ion collisions are less affected by the medium and more similar to pp(p)collisions.
