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
It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to un...It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics （QCD）. Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson-Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudo- critical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region.展开更多
A much simpler and self-consistent derivation of the non-linear component Gu×Gv of the quantum chromodynamic SU(3) field tensor is given which does not require the postulate of color confinement to complete the d...A much simpler and self-consistent derivation of the non-linear component Gu×Gv of the quantum chromodynamic SU(3) field tensor is given which does not require the postulate of color confinement to complete the derivation and which mirrors SU(2)’s formal development.展开更多
β decay is one of the most fundamental and thoroughly studied nuclear decay. Surprisingly, the β decay rates were found to have a periodic time variability [1]. However, others argued that there is no evidence for s...β decay is one of the most fundamental and thoroughly studied nuclear decay. Surprisingly, the β decay rates were found to have a periodic time variability [1]. However, others argued that there is no evidence for such cyclic deviation from the exponential first order kinetics decay law [2]. Here we propose that the β decay is a pseudo-first order exchange reaction triggered by uddũexotic mesons and propose a QCD gas theory. In analogy to the atmospheric gas density, the proposed QCD gas density drops with elevation from the sun. Accordingly, we propose that the β decay rate periodic variability is due to the pseudo-first order exchange reaction kinetics and the QCD gas atmospheric density drop. The proposed QCD gas may be a possible candidate for Einstein’s general theory of relativity ether [3]. Our main results are the derived formulas for calculating the effective mass of the QCD gas and the cosmology perfect fluid equation of state dimensionless parameter, based on the measured ratio of the β decay rates at the earth trajectory aphelion and perihelion dates. .展开更多
Based on a generalized Yang-Mills framework, gravitational and strong interactions can be unified in analogy with the unification in the electroweak theory. By gauging T （4） × [SU （3）] color in flat space-tim...Based on a generalized Yang-Mills framework, gravitational and strong interactions can be unified in analogy with the unification in the electroweak theory. By gauging T （4） × [SU （3）] color in flat space-time, we have a unified model of chromo-gravity with a new tensor gauge field, which couples universally to all gluons, quarks and anti-quarks. The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same ‘effective Riemann metric tensors’ in the geometric-optics （or classical） limit. The emergence of ef f ective metric tensors in the classical limit is essential for the unified model to agree with experiments. The unified model suggests that all gravitational, strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework.展开更多
9.1. Basics Quantum Chromodynamics （QCD）, the gauge field theory that describes the strong interactions of colored quarks and gluons, is the SU（3） component of the SU（3）×SU（2）×U（1） Standard Model ...9.1. Basics Quantum Chromodynamics （QCD）, the gauge field theory that describes the strong interactions of colored quarks and gluons, is the SU（3） component of the SU（3）×SU（2）×U（1） Standard Model of Particle Physics.展开更多
Updated September 2013 by S. Hashimoto （KEK）, J. Laiho （Syracuse University）, and S.R. Sharpe （University of Washington）. 18.1. Lattice regularization of QCD
The observations of fully-charm tetraquark states in the LHCb,CMS,and ATLAS experiments suggested the existence of hadronic molecules of two-charmonium states,which may also imply bound states in the threecharmonium s...The observations of fully-charm tetraquark states in the LHCb,CMS,and ATLAS experiments suggested the existence of hadronic molecules of two-charmonium states,which may also imply bound states in the threecharmonium systems.In this work,we study the possible bound states in the triple-ηcand triple-J/ψsystems with J^(PC)=0^(-+)and 1^(--),respectively.In quantum chromodynamics sum rules,we calculate the two-point correlation functions and spectral functions up to the dimension-four gluon condensate.We use the iterative dispersion relation approach to deal with the five-loop banana integrals,which significantly improves computational efficiency.Our results show that the masses of triple-ηcand triple-J/ψstates lie below the corresponding mass thresholds,supporting the existence of such three-body bound states.展开更多
Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental tech...Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.展开更多
We present a concise review of the vector charmonium state ψ(4230), which was originally labelled as Y(4260)in the literature. As one of the earliest candidates for a quantum chromodynamics exotic states, its interpr...We present a concise review of the vector charmonium state ψ(4230), which was originally labelled as Y(4260)in the literature. As one of the earliest candidates for a quantum chromodynamics exotic states, its interpretation has initiated various ideas about possible manifestations of non-perturbative mechanisms in the charmonium mass regime. In this short article we briefly review the experimental status of ψ(4230) and discuss possible theoretical interpretations. We will focus on four broadly investigated scenarios, i.e., tetraquark, hybrid, hadro-quarkonium,and hadronic molecule, and highlight the key issues based on these approaches. Crucial experimental observables,e.g., mass position, lineshapes, di-lepton decay width Γ_(ee), production rates in B meson decays, dominant hadronic decay patterns, and the potential 1^(-+)and 0^(--)exotic partners, are assessed, which can provide crucial structure information for understanding this mysterious state.展开更多
We extend a well-known mass-gap equation for pure gluodynamics in global colour models(formulated in equal-time quantization in Coulomb gauge)to one in which gluons are split into two sets,each exhibiting different ma...We extend a well-known mass-gap equation for pure gluodynamics in global colour models(formulated in equal-time quantization in Coulomb gauge)to one in which gluons are split into two sets,each exhibiting different masses.If the theory is SU(N)×SU(M)with gluons in both groups having identical couplings(as suggested by Grand Unification arguments at large scales)it is immediate to see that different masses are generated for each subgroup.This global symmetry is not broken,but the split masses erase accidental symmetries that might be present due to the two couplings being the same at a large scale,such as SU(N×M)or similar.We also numerically explore a couple of low-dimensional examples of simple Lie groups,but in spite of the system of equations having a form that would seem to allow spontaneous symmetry breaking,it is not triggered for these groups whose algebra has no ideal,and the dispersion relations for the various gluons converge to the same form.展开更多
能量扫描理论合作组(Beam Energy Scan Theory Collaboration,BEST)的目标是建立一个可以描述美国相对论重离子对撞机(Relativistic Heavy-Ion Collider,RHIC)上第二期能量扫描实验的动力学框架。该实验有可能找到强相互作用相图上的临...能量扫描理论合作组(Beam Energy Scan Theory Collaboration,BEST)的目标是建立一个可以描述美国相对论重离子对撞机(Relativistic Heavy-Ion Collider,RHIC)上第二期能量扫描实验的动力学框架。该实验有可能找到强相互作用相图上的临界点。本文总结自2016年起,BEST合作组取得重要进展,并对未来探索中高密度区相图做了展望。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
In this article we modify our previous model for the mechanisms underlying the glitch phenomena in pulsars. Accordingly, pulsars are born with embryonic cores that are made of purely incompressible superconducting glu...In this article we modify our previous model for the mechanisms underlying the glitch phenomena in pulsars. Accordingly, pulsars are born with embryonic cores that are made of purely incompressible superconducting gluon-quark superfluid (henceforth SuSu-cores). As the ambient medium cools and spins down due to emission of magnetic dipole radiation, the mass and size of SuSu-cores must grow discretely with time, in accordance with the Onsager-Feynmann analysis of superfluidity. Here we argue that the spacetime embedding glitching pulsars is dynamical and of bimetric nature: inside SuSu-cores the spacetime must be flat, whereas the surrounding region, where the matter is compressible and dissipative, the spacetime is Schwarzschild. It is argued here that the topological change of spacetime is derived by the strong nuclear force, whose operating length scales are found to increase with time to reach O (1) cm at the end of the luminous lifetimes of pulsars. The here-presented model is in line with the recent radio- and gravitational wave observations of pulsars and merger of neutron stars.展开更多
The Crab and Vela are well-studied glitching pulsars and the data obtained so far should enable us to test the reliability of models of their internal structures. Very recently it was proposed that glitching pulsars a...The Crab and Vela are well-studied glitching pulsars and the data obtained so far should enable us to test the reliability of models of their internal structures. Very recently it was proposed that glitching pulsars are embedded in bimetric spacetime: their incompressible superfluid cores (SuSu-cores) are embedded in flat spacetime, whereas the ambient compressible and dissipative media are enclosed in Schwarzschild spacetime. In this letter we apply this model to the Crab and Vela pulsars and show that a newly born pulsar initially of and an embryonic SuSu-core of could evolve into a Crab-like pulsar after 1000 years and into a Vela-like pulsar 10,000 years later to finally fade away as an invisible dark energy object after roughly 10 Myr. Based thereon we infer that the Crab and the Vela pulsars should have SuSu-cores of and , respectively. Furthermore, the under- and overshootings phenomena observed to accompany the glitch events of the Vela pulsar are rather a common phenomenon of glitching pulsars that can be well-explained within the framework of bimetric spacetime.展开更多
Recent astronomical observations of high redshift quasars, dark matter-dominated galaxies, mergers of neutron stars, glitch phenomena in pulsars, cosmic microwave background and experimental data from hadronic collide...Recent astronomical observations of high redshift quasars, dark matter-dominated galaxies, mergers of neutron stars, glitch phenomena in pulsars, cosmic microwave background and experimental data from hadronic colliders do not rule out, but they even support the hypothesis that the energy-density in our universe most likely is upper-limited by <span style="white-space:nowrap;"><i>p<sub>max</sub><sup style="margin-left:-25px;">uni</sup></i> </span>which is predicted to lie between 2 to 3 the nuclear density <em>p</em><sub>0</sub>. Quantum fluids in the cores of massive NSs with <em>p </em><span style="white-space:nowrap;"><span style="white-space:nowrap;">≈</span><i> <span style="white-space:nowrap;"><i>p<sub>max</sub><sup style="margin-left:-25px;">uni</sup></i> </span></i><span style="white-space:nowrap;">e</span>a</span>ch the maximum compressibility state, where they become insensitive to further compression by the embedding spacetime and undergo a phase transition into the purely incompressible gluon-quark superfluid state. A direct correspondence between the positive energy stored in the embedding spacetime and the degree of compressibility and superfluidity of the trapped matter is proposed. In this paper relevant observational signatures that support the maximum density hypothesis are reviewed, a possible origin of <span style="white-space:nowrap;"><i>p<sub>max</sub><sup style="margin-left:-25px;">uni</sup></i> </span>i<span style="white-space:nowrap;">s pr</span>oposed and finally the consequences of this scenario on the spacetime’s topology of the universe as well as on the mechanisms underlying the growth rate and power of the high redshift QSOs are discussed.展开更多
We give a direct method for calculating the quark-number susceptibility at finite chemical potential and zero temperature. In this approach the quark-number susceptibility is totally determined by G[μ]（p） （the dre...We give a direct method for calculating the quark-number susceptibility at finite chemical potential and zero temperature. In this approach the quark-number susceptibility is totally determined by G[μ]（p） （the dressed quark propagator at finite chemical potential μ）. By applying the general result in our previous study [Phys. Rev. C 71 （2005） 015205, 034901, 73 （2006） 016004 ] G[μ]（p） is calculated from the model quark propagator proposed by Pagels and Stokar [Phys. Rev. D 20 （1979） 2947]. The full analytic expression of the quark-number susceptibility at finite μ and zero T is obtained.展开更多
With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtai...With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtained masses of the two radial excitations are comparable with the experimental data.展开更多
We present the results for the transition temperature of quantum chromodynamics （QCD） with two degenerate flavours （Nf = 2） of Wilson quarks. On lattice 8^3 × 4 with 4 representing the temporal extent, by usi...We present the results for the transition temperature of quantum chromodynamics （QCD） with two degenerate flavours （Nf = 2） of Wilson quarks. On lattice 8^3 × 4 with 4 representing the temporal extent, by using the Ferrenberg-Swendsen reweighting method, we determine the critical β = 6/g^2 where the transition occurs, g is the coupling constant. On lattice 8^2 × 20 × 4, by using the axial vector Ward-Takahashi identity, we calculate the current quark mass amq, a is the lattice spacing. Assuming the O（4） scaling, the critical β in the chiral limit is determined. We calculate the p meson mass amp at zero temperature on lattice 8^3 × 20. By using the experimental p meson mass to set the scale, we obtain 194（1） MeV for the transition temperature in the chiral limit.展开更多
Based on the external field approach and the differential form of Ward identity, we derive a more compact formula for the particle-number susceptibility in QED3 at finite temperature. Using the zero frequency approxim...Based on the external field approach and the differential form of Ward identity, we derive a more compact formula for the particle-number susceptibility in QED3 at finite temperature. Using the zero frequency approximation the numerical value of the particle-number susceptibility is calculated in the Dyson-Schwinger approach for the case that the number of fermion flavours equals one and two, respectively. An enhanced fluctuation of the particlenumber density is observed across the transition temperature, which should be an essential characteristic of chiral phase transition in QED3.展开更多
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Supported by the National Natural Science Foundation of China under Grant Nos 11275097,11475085,11535005,and 11265017the Jiangsu Planned Projects for Postdoctoral Research Funds under Grant No 1402006C+2 种基金the China Postdoctoral Science Foundation under Grant No 2015M571728the Natural Science Foundation of Jiangsu Province under Grant No BK20130078the Guizhou-Provincial Outstanding Youth Science and Technology Talent Cultivation Object Special Funds under Grant No QKHRZ(2013)28
文摘It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics （QCD）. Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson-Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudo- critical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region.
文摘A much simpler and self-consistent derivation of the non-linear component Gu×Gv of the quantum chromodynamic SU(3) field tensor is given which does not require the postulate of color confinement to complete the derivation and which mirrors SU(2)’s formal development.
文摘β decay is one of the most fundamental and thoroughly studied nuclear decay. Surprisingly, the β decay rates were found to have a periodic time variability [1]. However, others argued that there is no evidence for such cyclic deviation from the exponential first order kinetics decay law [2]. Here we propose that the β decay is a pseudo-first order exchange reaction triggered by uddũexotic mesons and propose a QCD gas theory. In analogy to the atmospheric gas density, the proposed QCD gas density drops with elevation from the sun. Accordingly, we propose that the β decay rate periodic variability is due to the pseudo-first order exchange reaction kinetics and the QCD gas atmospheric density drop. The proposed QCD gas may be a possible candidate for Einstein’s general theory of relativity ether [3]. Our main results are the derived formulas for calculating the effective mass of the QCD gas and the cosmology perfect fluid equation of state dimensionless parameter, based on the measured ratio of the β decay rates at the earth trajectory aphelion and perihelion dates. .
基金Supported by Jing Shin Research Fund of UMassD Foundation
文摘Based on a generalized Yang-Mills framework, gravitational and strong interactions can be unified in analogy with the unification in the electroweak theory. By gauging T （4） × [SU （3）] color in flat space-time, we have a unified model of chromo-gravity with a new tensor gauge field, which couples universally to all gluons, quarks and anti-quarks. The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same ‘effective Riemann metric tensors’ in the geometric-optics （or classical） limit. The emergence of ef f ective metric tensors in the classical limit is essential for the unified model to agree with experiments. The unified model suggests that all gravitational, strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework.
文摘9.1. Basics Quantum Chromodynamics （QCD）, the gauge field theory that describes the strong interactions of colored quarks and gluons, is the SU（3） component of the SU（3）×SU（2）×U（1） Standard Model of Particle Physics.
文摘Updated September 2013 by S. Hashimoto （KEK）, J. Laiho （Syracuse University）, and S.R. Sharpe （University of Washington）. 18.1. Lattice regularization of QCD
基金supported by the National Natural Science Foundation of China(Grant No.12175318)the Natural Science Foundation of Guangdong Province of China(Grant No.2023A1515011704)。
文摘The observations of fully-charm tetraquark states in the LHCb,CMS,and ATLAS experiments suggested the existence of hadronic molecules of two-charmonium states,which may also imply bound states in the threecharmonium systems.In this work,we study the possible bound states in the triple-ηcand triple-J/ψsystems with J^(PC)=0^(-+)and 1^(--),respectively.In quantum chromodynamics sum rules,we calculate the two-point correlation functions and spectral functions up to the dimension-four gluon condensate.We use the iterative dispersion relation approach to deal with the five-loop banana integrals,which significantly improves computational efficiency.Our results show that the masses of triple-ηcand triple-J/ψstates lie below the corresponding mass thresholds,supporting the existence of such three-body bound states.
基金supported by the the National Key R&D Program of China(Grant Nos.2022YFA1604900 and 2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12025501,12435007,12405133,and 12347180)+1 种基金China Postdoctoral Science Foundation(Grant No.2023M740189)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233381).
文摘Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.
基金supported in part by the National Natural Science Foundation of China (Grant Nos.12375073 and 12235018)。
文摘We present a concise review of the vector charmonium state ψ(4230), which was originally labelled as Y(4260)in the literature. As one of the earliest candidates for a quantum chromodynamics exotic states, its interpretation has initiated various ideas about possible manifestations of non-perturbative mechanisms in the charmonium mass regime. In this short article we briefly review the experimental status of ψ(4230) and discuss possible theoretical interpretations. We will focus on four broadly investigated scenarios, i.e., tetraquark, hybrid, hadro-quarkonium,and hadronic molecule, and highlight the key issues based on these approaches. Crucial experimental observables,e.g., mass position, lineshapes, di-lepton decay width Γ_(ee), production rates in B meson decays, dominant hadronic decay patterns, and the potential 1^(-+)and 0^(--)exotic partners, are assessed, which can provide crucial structure information for understanding this mysterious state.
基金supported by the EU under grant 824093(STRONG2020)spanish MICINN under PID2019-108655GBI00/AEI/10.13039/501100011033,PID2019-106080GB-C21 and PRX23/00225(estancias en el extranjero)Univ.Complutense de Madrid under research group 910309 and the IPARCOS institute。
文摘We extend a well-known mass-gap equation for pure gluodynamics in global colour models(formulated in equal-time quantization in Coulomb gauge)to one in which gluons are split into two sets,each exhibiting different masses.If the theory is SU(N)×SU(M)with gluons in both groups having identical couplings(as suggested by Grand Unification arguments at large scales)it is immediate to see that different masses are generated for each subgroup.This global symmetry is not broken,but the split masses erase accidental symmetries that might be present due to the two couplings being the same at a large scale,such as SU(N×M)or similar.We also numerically explore a couple of low-dimensional examples of simple Lie groups,but in spite of the system of equations having a form that would seem to allow spontaneous symmetry breaking,it is not triggered for these groups whose algebra has no ideal,and the dispersion relations for the various gluons converge to the same form.
文摘能量扫描理论合作组(Beam Energy Scan Theory Collaboration,BEST)的目标是建立一个可以描述美国相对论重离子对撞机(Relativistic Heavy-Ion Collider,RHIC)上第二期能量扫描实验的动力学框架。该实验有可能找到强相互作用相图上的临界点。本文总结自2016年起,BEST合作组取得重要进展,并对未来探索中高密度区相图做了展望。
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In this article we modify our previous model for the mechanisms underlying the glitch phenomena in pulsars. Accordingly, pulsars are born with embryonic cores that are made of purely incompressible superconducting gluon-quark superfluid (henceforth SuSu-cores). As the ambient medium cools and spins down due to emission of magnetic dipole radiation, the mass and size of SuSu-cores must grow discretely with time, in accordance with the Onsager-Feynmann analysis of superfluidity. Here we argue that the spacetime embedding glitching pulsars is dynamical and of bimetric nature: inside SuSu-cores the spacetime must be flat, whereas the surrounding region, where the matter is compressible and dissipative, the spacetime is Schwarzschild. It is argued here that the topological change of spacetime is derived by the strong nuclear force, whose operating length scales are found to increase with time to reach O (1) cm at the end of the luminous lifetimes of pulsars. The here-presented model is in line with the recent radio- and gravitational wave observations of pulsars and merger of neutron stars.
文摘The Crab and Vela are well-studied glitching pulsars and the data obtained so far should enable us to test the reliability of models of their internal structures. Very recently it was proposed that glitching pulsars are embedded in bimetric spacetime: their incompressible superfluid cores (SuSu-cores) are embedded in flat spacetime, whereas the ambient compressible and dissipative media are enclosed in Schwarzschild spacetime. In this letter we apply this model to the Crab and Vela pulsars and show that a newly born pulsar initially of and an embryonic SuSu-core of could evolve into a Crab-like pulsar after 1000 years and into a Vela-like pulsar 10,000 years later to finally fade away as an invisible dark energy object after roughly 10 Myr. Based thereon we infer that the Crab and the Vela pulsars should have SuSu-cores of and , respectively. Furthermore, the under- and overshootings phenomena observed to accompany the glitch events of the Vela pulsar are rather a common phenomenon of glitching pulsars that can be well-explained within the framework of bimetric spacetime.
文摘Recent astronomical observations of high redshift quasars, dark matter-dominated galaxies, mergers of neutron stars, glitch phenomena in pulsars, cosmic microwave background and experimental data from hadronic colliders do not rule out, but they even support the hypothesis that the energy-density in our universe most likely is upper-limited by <span style="white-space:nowrap;"><i>p<sub>max</sub><sup style="margin-left:-25px;">uni</sup></i> </span>which is predicted to lie between 2 to 3 the nuclear density <em>p</em><sub>0</sub>. Quantum fluids in the cores of massive NSs with <em>p </em><span style="white-space:nowrap;"><span style="white-space:nowrap;">≈</span><i> <span style="white-space:nowrap;"><i>p<sub>max</sub><sup style="margin-left:-25px;">uni</sup></i> </span></i><span style="white-space:nowrap;">e</span>a</span>ch the maximum compressibility state, where they become insensitive to further compression by the embedding spacetime and undergo a phase transition into the purely incompressible gluon-quark superfluid state. A direct correspondence between the positive energy stored in the embedding spacetime and the degree of compressibility and superfluidity of the trapped matter is proposed. In this paper relevant observational signatures that support the maximum density hypothesis are reviewed, a possible origin of <span style="white-space:nowrap;"><i>p<sub>max</sub><sup style="margin-left:-25px;">uni</sup></i> </span>i<span style="white-space:nowrap;">s pr</span>oposed and finally the consequences of this scenario on the spacetime’s topology of the universe as well as on the mechanisms underlying the growth rate and power of the high redshift QSOs are discussed.
基金Supported in part by the National Natural Science Foundation of China under Grant No 10575050, and the Research Fund for the Doctoral Programme of Higher Education in China under Grant No 20060284020.
文摘We give a direct method for calculating the quark-number susceptibility at finite chemical potential and zero temperature. In this approach the quark-number susceptibility is totally determined by G[μ]（p） （the dressed quark propagator at finite chemical potential μ）. By applying the general result in our previous study [Phys. Rev. C 71 （2005） 015205, 034901, 73 （2006） 016004 ] G[μ]（p） is calculated from the model quark propagator proposed by Pagels and Stokar [Phys. Rev. D 20 （1979） 2947]. The full analytic expression of the quark-number susceptibility at finite μ and zero T is obtained.
基金Supported by the National Natural Science Foundation of China under contract Nos 10425521, 10575004 and 106750077 the Key Project of the Ministry of Education of China under Grant No 305001, the Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20040001010, and the Foundation for University Key Teachers by the Ministry of Education of China.
文摘With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtained masses of the two radial excitations are comparable with the experimental data.
文摘We present the results for the transition temperature of quantum chromodynamics （QCD） with two degenerate flavours （Nf = 2） of Wilson quarks. On lattice 8^3 × 4 with 4 representing the temporal extent, by using the Ferrenberg-Swendsen reweighting method, we determine the critical β = 6/g^2 where the transition occurs, g is the coupling constant. On lattice 8^2 × 20 × 4, by using the axial vector Ward-Takahashi identity, we calculate the current quark mass amq, a is the lattice spacing. Assuming the O（4） scaling, the critical β in the chiral limit is determined. We calculate the p meson mass amp at zero temperature on lattice 8^3 × 20. By using the experimental p meson mass to set the scale, we obtain 194（1） MeV for the transition temperature in the chiral limit.
基金Supported in part by the National Natural Science Foundation of China under Grant Nos 10575050 and 10775069, and the Research Fund for the Doctoral Programme of Higher Education under Grant No 20060284020.
文摘Based on the external field approach and the differential form of Ward identity, we derive a more compact formula for the particle-number susceptibility in QED3 at finite temperature. Using the zero frequency approximation the numerical value of the particle-number susceptibility is calculated in the Dyson-Schwinger approach for the case that the number of fermion flavours equals one and two, respectively. An enhanced fluctuation of the particlenumber density is observed across the transition temperature, which should be an essential characteristic of chiral phase transition in QED3.
