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
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
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
Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model par...Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.展开更多
Discovery of the X(3872)meson in 2003 ignited intense interest in exotic(neither qq nor qqq)hadrons,but a cc interpretation of this state was difficult to exclude.An unequivocal exotic was discovered in the Z_(c)(3900...Discovery of the X(3872)meson in 2003 ignited intense interest in exotic(neither qq nor qqq)hadrons,but a cc interpretation of this state was difficult to exclude.An unequivocal exotic was discovered in the Z_(c)(3900)^(+)meson—a charged charmonium-like state.A variety of models of exotic structure have been advanced but consensus is elusive.The grand lesson from heavy quarkonia was that heavy quarks bring clarity.Thus,the recently reported triplet of all-charm tetraquark candidates—X(6600),X(6900),and X(7100)—decaying to J/ψJ/ψ is a great boon,promising important insights.We review some history of exotics,chronicle the road to prospective all-charm tetraquarks,discuss in some detail the divergent modeling of J/ψJ/ψ structures,and offer some inferences about them.These states form a Regge trajectory and appear to be a family of radial excitations.A reported,but unexplained,threshold excess could hint at a fourth family member.We close with a brief look at a step beyond:all-bottom tetraquarks.展开更多
This work shows a didactic model representative of the quarks described in the Standard Model (SM). In the model, particles are represented by structures corresponding to geometric shapes of coupled quantum oscillator...This work shows a didactic model representative of the quarks described in the Standard Model (SM). In the model, particles are represented by structures corresponding to geometric shapes of coupled quantum oscillators (GMP). From these didactic hypotheses emerges an in-depth phenomenology of particles (quarks) fully compatible with that of SM, showing, besides, that the number of possible quarks is six.展开更多
The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons,...The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons, & mesons) and their components (quarks), mass difference between nucleus and its individual components (protons and neutrons), massless of gamma photons, abnormal masses of mesons and bosons, and the excess in galaxy masses (dark matter). Also, this proposal shows the exact relation between mass and energy: Strong Potential=−3.04mc2| Electric Potential |=−5.57×10−3mc2Gravitational Potential=−1.22×10−7mc2where m represents the excess in mass due to strong potential, or gravitational potential and represents the decrease in mass due to electromagnetic potential. Released energy here equals potential energy and doesn’t equal decrease in mass using the formula E = mc2. Released energy is transferred to heat, photons, kinetic energy… Finally, proposal will try to describe the relation between photon energy and mass of its components using the general equation of kinetic energy: Photon Energy=1/2mc2m is the sum of the individual masses of its components, while the total mass of photon is zero.展开更多
The understanding of the mechanism for the mass building of elementary particles of Standard Model (SM) has made significant progresses since the confirmation of the existence of the Higgs boson, in particular the rea...The understanding of the mechanism for the mass building of elementary particles of Standard Model (SM) has made significant progresses since the confirmation of the existence of the Higgs boson, in particular the realization that the mass of an elementary particle of SM is not “God-given” but is created by interactions with involved energy fields. Nevertheless, a sophisticated model to answer fundamental questions is still missing. Further research is needed to compensate for the existing deficit. The current paper is aimed to contribute to such research by using “harmonic quark series”. Harmonic quark series were introduced between 2003 and 2005 by O. A. Teplov and represented a relatively new approach to understanding the physical masses of elementary particles. Although they are not generally recognized, some research works have revealed very interesting and exciting facts regarding the mass quanta. The original harmonic quark series consists of mathematical “quark” entities with an energy-mass quantum between 7.87 MeV and 69.2 GeV. They obey a strict mathematical rule derived from the general harmonic oscillation theory. Teplov showed some quantitative relations between the masses of his harmonic quarks and the SM particles, especially in the intermediate mass range, i.e. mesons and hadrons up to 1000 MeV. Early research work also includes the investigation of H. Yang/W. Yang in the development of their so-called YY model for elementary particles (Ying-Yang model with “Ying” and “Yang” as quark components for a new theoretical particle framework). Based on Teplov’s scheme and its mathematical formula, they introduced further harmonic quarks down to 1 eV and showed some quantitative relationships between the masses of these harmonic quarks and the masses of electrons and up and down quarks. In this article, we will extend the harmonic quark series according to the Teplov scheme up to a new entity with a mass quantum of 253.4 GeV and show some interesting new mass relations to the heavy particles of the Standard Model (W boson, Z boson, top quark and Higgs boson). Based on these facts, some predictions will be made for experimental verification. We also hope that our investigation and result will motivate more researcher to dedicate their work to harmonic quark series in theory and in experiments.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
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.
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.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1606703)the National Natural Science Foundation of China(Grant No.12075288)the Youth Innovation Promotion Association CAS.
文摘Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.
基金supported by the Research Start-Up Funding Project of Nanjing Normal Universitythe National Natural Science Foundation of China(Grant Nos.12075123 and 12061141002)the National Science Research and Development Program of China(Grant No.2023YFA1605804)。
文摘Discovery of the X(3872)meson in 2003 ignited intense interest in exotic(neither qq nor qqq)hadrons,but a cc interpretation of this state was difficult to exclude.An unequivocal exotic was discovered in the Z_(c)(3900)^(+)meson—a charged charmonium-like state.A variety of models of exotic structure have been advanced but consensus is elusive.The grand lesson from heavy quarkonia was that heavy quarks bring clarity.Thus,the recently reported triplet of all-charm tetraquark candidates—X(6600),X(6900),and X(7100)—decaying to J/ψJ/ψ is a great boon,promising important insights.We review some history of exotics,chronicle the road to prospective all-charm tetraquarks,discuss in some detail the divergent modeling of J/ψJ/ψ structures,and offer some inferences about them.These states form a Regge trajectory and appear to be a family of radial excitations.A reported,but unexplained,threshold excess could hint at a fourth family member.We close with a brief look at a step beyond:all-bottom tetraquarks.
文摘This work shows a didactic model representative of the quarks described in the Standard Model (SM). In the model, particles are represented by structures corresponding to geometric shapes of coupled quantum oscillators (GMP). From these didactic hypotheses emerges an in-depth phenomenology of particles (quarks) fully compatible with that of SM, showing, besides, that the number of possible quarks is six.
文摘The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons, & mesons) and their components (quarks), mass difference between nucleus and its individual components (protons and neutrons), massless of gamma photons, abnormal masses of mesons and bosons, and the excess in galaxy masses (dark matter). Also, this proposal shows the exact relation between mass and energy: Strong Potential=−3.04mc2| Electric Potential |=−5.57×10−3mc2Gravitational Potential=−1.22×10−7mc2where m represents the excess in mass due to strong potential, or gravitational potential and represents the decrease in mass due to electromagnetic potential. Released energy here equals potential energy and doesn’t equal decrease in mass using the formula E = mc2. Released energy is transferred to heat, photons, kinetic energy… Finally, proposal will try to describe the relation between photon energy and mass of its components using the general equation of kinetic energy: Photon Energy=1/2mc2m is the sum of the individual masses of its components, while the total mass of photon is zero.
文摘The understanding of the mechanism for the mass building of elementary particles of Standard Model (SM) has made significant progresses since the confirmation of the existence of the Higgs boson, in particular the realization that the mass of an elementary particle of SM is not “God-given” but is created by interactions with involved energy fields. Nevertheless, a sophisticated model to answer fundamental questions is still missing. Further research is needed to compensate for the existing deficit. The current paper is aimed to contribute to such research by using “harmonic quark series”. Harmonic quark series were introduced between 2003 and 2005 by O. A. Teplov and represented a relatively new approach to understanding the physical masses of elementary particles. Although they are not generally recognized, some research works have revealed very interesting and exciting facts regarding the mass quanta. The original harmonic quark series consists of mathematical “quark” entities with an energy-mass quantum between 7.87 MeV and 69.2 GeV. They obey a strict mathematical rule derived from the general harmonic oscillation theory. Teplov showed some quantitative relations between the masses of his harmonic quarks and the SM particles, especially in the intermediate mass range, i.e. mesons and hadrons up to 1000 MeV. Early research work also includes the investigation of H. Yang/W. Yang in the development of their so-called YY model for elementary particles (Ying-Yang model with “Ying” and “Yang” as quark components for a new theoretical particle framework). Based on Teplov’s scheme and its mathematical formula, they introduced further harmonic quarks down to 1 eV and showed some quantitative relationships between the masses of these harmonic quarks and the masses of electrons and up and down quarks. In this article, we will extend the harmonic quark series according to the Teplov scheme up to a new entity with a mass quantum of 253.4 GeV and show some interesting new mass relations to the heavy particles of the Standard Model (W boson, Z boson, top quark and Higgs boson). Based on these facts, some predictions will be made for experimental verification. We also hope that our investigation and result will motivate more researcher to dedicate their work to harmonic quark series in theory and in experiments.
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.
