We propose the revised description of a baryon as a composition of bound stated sea-quarks and unbound stated sea-quarks from the previously proposed description of baryon as a meson pair. The purpose of this article ...We propose the revised description of a baryon as a composition of bound stated sea-quarks and unbound stated sea-quarks from the previously proposed description of baryon as a meson pair. The purpose of this article is to show the following two possibilities. The first one shows the qualitative explanation to support our description of a nucleon as a pair of pions and the second one is that it gives an explanation of ALICE results that the pTdependence of Λc+/D0ratio is 0.5. Each isospin group is constructed of both baryons and antibaryons. This way of construction is consistent with that of mesons. The results obtained are listed in tables. This shows that the generalized Gell-Mann-Nishijima relation equation holds under the condition that the baryon number is 0.展开更多
In nuclear collisions at RHIC energies, an excess of Ω hyperons over ■ is observed, indicating that Ω has a net baryon number despite s and s quarks being produced in pairs. The baryon number in Ω may have been tr...In nuclear collisions at RHIC energies, an excess of Ω hyperons over ■ is observed, indicating that Ω has a net baryon number despite s and s quarks being produced in pairs. The baryon number in Ω may have been transported from the incident nuclei and/or produced in the baryon-pair production of Ω with other types of anti-hyperons such as Ξ. To investigate these two scenarios, we propose to measure the correlations between Ω and K and between Ω and anti-hyperons. We use two versions, the default and string-melting, of a multiphase transport(AMPT) model to illustrate the method for measuring the correlation and to demonstrate the general shape of the correlation. We present the Ω-hadron correlations from simulated Au+Au collisions at ■ =7.7 and 14.6 Ge V and discuss the dependence on the collision energy and on the hadronization scheme in these two AMPT versions. These correlations can be used to explore the mechanism of baryon number transport and the effects of baryon number and strangeness conservation on nuclear collisions.展开更多
The initial idea for baryonic acoustic oscillations (BAO) came about during early efforts to understand the origin of galaxies by studying perturbed versions of the Friedmann-Robertson-Walker (FRW) model. In more rece...The initial idea for baryonic acoustic oscillations (BAO) came about during early efforts to understand the origin of galaxies by studying perturbed versions of the Friedmann-Robertson-Walker (FRW) model. In more recent times, the emphasis has shifted to the idea that 2-point galaxy correlations embedded in the distribution of matter by the BAO could be used as a standard ruler to fix the parameters of cosmological models. In this paper, we first consider the actual business of extracting the correlation length from large data sets of measured galaxy locations. To facilitate this process, we introduce a much-improved method for extracting the correlation peak from the data set. Fundamental to this process in any model is the use of a fiducial cosmological model to transition from redshift space to comoving coordinate space where the correlations actually exist. The belief is that the correlation length so determined can then be reverted to redshift space to fix the parameters of cosmological models. We show, however, that this process is circular and hence of no value whatsoever for fixing model parameters. All one obtains are the parameters of the model used to transition to comoving space in the first place. Finally, we present simple arguments that show that the idea of BAO being responsible for the structure of the universe, i.e. the cosmic web, is unworkable.展开更多
We propose a new description of a baryon as a pair of mesons. This description is an extension of the previously proposed description of a nucleon as a pair of pions. The purpose of this article is to show the followi...We propose a new description of a baryon as a pair of mesons. This description is an extension of the previously proposed description of a nucleon as a pair of pions. The purpose of this article is to show the following two possibilities. The first one is that it shows the qualitative explanation to support our description of a nucleon as a pair of pions and the second one is that it gives the systematic way of estimation of baryon mass not only for light baryons but also for heavy baryons (charm baryons and bottom baryons). Each isospin group is constructed of both baryons and antibaryons. This way of construction is consistent with that of mesons. The results obtained are listed in tables (Tables 1-9). This shows that the generalized Gell-Mann-Nishijima relation equation holds under the condition that the baryon number is 0 and that the obtained masses are fairly good, even for heavy baryons. Our description also yields several examples of baryon decay modes.展开更多
We study the masses of the doubly bottom baryons and the charmed-bottom baryons up to O(p^(3))in heavy baryon chiral perturbation theory.We determine the unknown low energy constants in the quark model and lattice QCD...We study the masses of the doubly bottom baryons and the charmed-bottom baryons up to O(p^(3))in heavy baryon chiral perturbation theory.We determine the unknown low energy constants in the quark model and lattice QCD.We show the numerical results for the masses of the doubly bottom baryons and the charmed-bottom baryons up to O(p^(3)).展开更多
This paper posits that the upward-going ANITA events are derived from the cosmic ray of the baryonic-dark matter (BDM) Higgs boson. In the extended standard model (ESM) for baryonic matter and dark matter, the spontan...This paper posits that the upward-going ANITA events are derived from the cosmic ray of the baryonic-dark matter (BDM) Higgs boson. In the extended standard model (ESM) for baryonic matter and dark matter, the spontaneous symmetry breaking through the Higgs mechanism for the symmetrical massless baryonic matter left-handed neutrinos and massless dark matter right-handed neutrinos produced massless baryonic matter left-handed neutrinos, sterile massive dark matter neutrinos, and the BDM Higgs boson. The BDM Higgs boson is the composite of the high-mass tau neutrino and the high-mass dark matter neutrino. During the passage through the high-density part of the Earth, the BDM Higgs boson is transformed into the oscillating BDM Higgs boson between the composite of the high-mass tau neutrino and the high-mass dark matter neutrino and the composite of the high-mass tau neutrino and the low-mass dark matter neutrino. The oscillating BDM Higgs boson decays into the high-mass tau neutrino with the extra energy and the low-mass dark matter neutrino (27 eV) in the low-density water-ice layer of the Earth. The high-mass tau neutrino is converted into ultra-high-energy tau neutrino which decays into tau lepton through the charged-current interactions, and tau lepton emerges from the surface of ice. Based on the periodic table of elementary particles, the calculated value for the high-mass tau neutrino with the extra energy is 0.47 EeV in good agreement with the observed 0.56 and 0.6 EeV. The periodic table of elementary particles for baryonic matter, dark matter, and gravity is based on the seven principal mass dimensional orbitals for stable baryonic matter leptons (electron and left-handed neutrinos), gauge bosons, gravity, and dark matter and the seven auxiliary mass dimensional orbitals for unstable leptons (muon and tau) and quarks, and calculates accurately the masses of all elementary particles and the cosmic rays by using only five known constants.展开更多
In this letter,the cosmic distance-duality relation has been constrained with a model-independent method by combining the baryon acoustic oscillation(BAO)data and the type Ia supernova(SNe Ia)data.The results show tha...In this letter,the cosmic distance-duality relation has been constrained with a model-independent method by combining the baryon acoustic oscillation(BAO)data and the type Ia supernova(SNe Ia)data.The results show that this relation is consistent with the observational data in the 68.27%error range,except for the instance of Union 2.1 plus BAO with the statistic errors only,where the relation is consistent with the observations in the 95.45%error range.To study the result of the uncertainty of the Hubble constant on the investigation of this relation,we treat the dimensionless Hubble constant h as a free parameter and get that the observational data favors the relation in the 68.27%error range.And then h has been marginalized and the results support that this relation is favored by the observations in the 68.27%error range too.展开更多
The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation featu...The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation features in the SPS and RHIC energy regions are investigated by taking advantage of the gluon saturation model with geometric scaling. Predications are made for the net-baryon rapidity distributions, mean rapidity loss and gluon saturation features in central Pb ＋ Pb collisions at LHC.展开更多
The exact solution of Sehrodinger equation corresponding to a baryonic system is the main interest in the present work. We take into account both quadratic and Coulomb terms in the potential relation. Next, after pres...The exact solution of Sehrodinger equation corresponding to a baryonic system is the main interest in the present work. We take into account both quadratic and Coulomb terms in the potential relation. Next, after presenting an exact solution, we have calculated the spin and isospin effects in both ground and excited states. The results are comparable with experimental data.展开更多
We use the latest baryon acoustic oscillation and Union 2.1 type Ia supernova data to test the cosmic opacity between different redshift regions without assuming any cosmological models. It is found that the universe ...We use the latest baryon acoustic oscillation and Union 2.1 type Ia supernova data to test the cosmic opacity between different redshift regions without assuming any cosmological models. It is found that the universe may be opaque between the redshift regions 0.35 0.44, 0.44 0.57 and 0.6-0.73 since the best fit values of cosmic opacity in these regions are positive, while a transparent universe is favored in the redshift region 0.57-0.63. However, in general, a transparent universe is still consistent with observations at the lo confidence level.展开更多
In this work, we calculate the mass spectrum of doubly heavy baryons with the diquaxk model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquaxk field and a light quark field. Cont...In this work, we calculate the mass spectrum of doubly heavy baryons with the diquaxk model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquaxk field and a light quark field. Contributions of the operators up to dimension six are taken into account in the operator product expansion. Within a reasonable error tolerance, our numerical results axe compatible with other theoretical predictions. This indicates that the diquaxk picture reflects the reality and is applicable to the study of doubly heavy baryons.展开更多
Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are ob...Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are obtained in a unified manner. Our result shows that by employing either the △-mode or the Y-mode confining potential, one can achieve reasonable baryon spectra. The △-mode may be mostly effective for the short- and medium-distances, while the Y-mode may offer more contributions to the spectra for long-distances. Although the binding energies in baryon spectra may deviate by a few to several tens MeV for different modes, it is hard to determine either one to be dominant by simply evaluating the baryon spectra. One may need to invoke the baryon decay process to make further judgement.展开更多
In the present work, the masses of the decuplet baryons at finite temperature are investigated using thermM QCD sum rules. Making use of the quark propagator at finite temperature, we caiculate the spectral functions ...In the present work, the masses of the decuplet baryons at finite temperature are investigated using thermM QCD sum rules. Making use of the quark propagator at finite temperature, we caiculate the spectral functions to T8 order, and find that there are no contributions to the spectral functions at T8 order and the temperature corrections mainly come from that containing T4 ones. The calculations show very little temperature dependence of the masses below T =0.11 GeV. While above that vaJue, the masses decrease with increasing temperature. The results indicate that the hadron-quark phase transition temperature may be Tc ≥ 0.11 GeV for the decuplet bayons.展开更多
Using the effective Hamiltonian method, we analyze the B0-B0 mixing in the extension of the standard model （SM） where baryon number and lepton number are local gauge symmetries. The numerical results indicate the co...Using the effective Hamiltonian method, we analyze the B0-B0 mixing in the extension of the standard model （SM） where baryon number and lepton number are local gauge symmetries. The numerical results indicate the correction from the extra particles to the mass difference ArnB is significant. There is a 60% enhancement compared to the SM prediction for AraB at most, which agrees with the current experimental result.展开更多
In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the param...In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the parameter space, we find that the branching ratios of t →cγ and t →cg can reach 10^-6 and 10^-5 respectively, which can be detected in near future.展开更多
From the equations of motion for baryons in the scalar strong interaction hadron theory (SSI), two coupled third order radial wave equations for baryon doublets have been derived and published in 1994. These equations...From the equations of motion for baryons in the scalar strong interaction hadron theory (SSI), two coupled third order radial wave equations for baryon doublets have been derived and published in 1994. These equations are solved numerically here, using quark masses obtained from meson spectra and the masses of the neutron, ?0 and ?0 as input. Confined wave functions dependent upon the quark-diquark distance as well as the values of the four integration constants entering the quark-diquark interaction potential are found approximately. These approximative, zeroth order results are employed in a first order perturbational treatment of the equations of motion for baryons in SSI for free neutron decay. The predicted magnitude of neutron’s half life agrees with data. If the only free parameter is adjusted to produce the known A asymmetry coefficient, the predicted B asymmetry agrees well with data and vice versa. It is pointed out that angular momentum is not conserved in free neutron decay and that the weak coupling constant is detached from the much stronger fine structure constant of electromagnetic coupling.展开更多
If most of the universe is made of baryons, we encounter a serious contradiction in explaining the observed structure formulation. Therefore, we need non-baryonic dark matter to comprise the universe. In a previous pa...If most of the universe is made of baryons, we encounter a serious contradiction in explaining the observed structure formulation. Therefore, we need non-baryonic dark matter to comprise the universe. In a previous paper, the present author proposed an infinite sub-layer quark model in which there exists an infinite number of up quark <i>q<sub>u</sub></i> (∞) and down quark <i>q<sub>d</sub></i> (∞) at an infinite sub-layer level. These quarks have non-baryon quantum number with one-half electric charge. Thus, <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks are candidates for the non-baryonic dark matter. It is then shown that CP is violated only in the doublet of <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks to account for the asymmetry of the number of particles and anti-particles in the present universe. It should be emphasized that if the internal space of <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks in the first generation is a noncommutative geometry, CP violation can be explained without increasing the number of particles and generations. Thus, a pair of an infinite number of <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks would be produced in the first moments after the Big Bang and form the hadrons including the nucleons and remain as the non-baryonic cold dark matter for all time. From the <i>q<sub>f</sub></i> (∞) quarks with the flavors <i>f</i> = <i>u</i>, <i>d</i>, <i>s</i>, <i>c</i>, <i>t</i>, and <i>b</i>, we compared our prediction value of the cross-section ratio <i>R</i> with the experimental values. We obtained the theoretical branching ratio <i>R</i> = 15/4 = 3.75 which is in good agreement with the experimental values from 12.00 GeV to 46.47 GeV in electron-positron annihilation into muon pairs and quark pairs.展开更多
Baryon magnetic moments of p, n, ∑^＋,∑^-,Ξ^0, Ξ^- and the beta decay ratios （G A/Gv ） of n → p, ∑^-→n and Ξ^0→∑^＋ are calculated in a colored quark cluster model. With SU（3） breaking, the model gives a...Baryon magnetic moments of p, n, ∑^＋,∑^-,Ξ^0, Ξ^- and the beta decay ratios （G A/Gv ） of n → p, ∑^-→n and Ξ^0→∑^＋ are calculated in a colored quark cluster model. With SU（3） breaking, the model gives a good fit to the experimental values of those baryon magnetic moments and the beta decay ratios. Our results show that the orbital motion has a significant contribution to the spin and magnetic moments of those baryons and the strange component in nucleon is small.展开更多
We study the ＇t Hooft coupling gt and the mass splitting of the ground-state baryons in terms of the large Noinspired quark model, by which the Hartree wavefunctions of light quarks are obtained. By fitting the spect...We study the ＇t Hooft coupling gt and the mass splitting of the ground-state baryons in terms of the large Noinspired quark model, by which the Hartree wavefunctions of light quarks are obtained. By fitting the spectra of decuplet and octet baryons, we obtain the ＇t Hooft coupling gt to be around 1.57. We generalize the scenario to the case of heavy baryons, such as Ac, gt values which does not deviate much from 1.57, as well as to the case of mesons with 9t far from that for baryons. The consequence is discussed.展开更多
In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams a...In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams are also included. The hadronic matrix elements are evaluated in the simple non-relativistic harmonic oscillator model. Our numerical results are generally consistent with that obtained by other authors who used the diquark model. However, all the theoretical predictions on the lifetimes are one order larger than the upper limit set by the recent SELEX measurement. This discrepancy would be clarified by the future experiment. If more accurate experiment still confirms the value of the SELEX collaboration, there must be some unknown mechanism to be explored.展开更多
文摘We propose the revised description of a baryon as a composition of bound stated sea-quarks and unbound stated sea-quarks from the previously proposed description of baryon as a meson pair. The purpose of this article is to show the following two possibilities. The first one shows the qualitative explanation to support our description of a nucleon as a pair of pions and the second one is that it gives an explanation of ALICE results that the pTdependence of Λc+/D0ratio is 0.5. Each isospin group is constructed of both baryons and antibaryons. This way of construction is consistent with that of mesons. The results obtained are listed in tables. This shows that the generalized Gell-Mann-Nishijima relation equation holds under the condition that the baryon number is 0.
文摘In nuclear collisions at RHIC energies, an excess of Ω hyperons over ■ is observed, indicating that Ω has a net baryon number despite s and s quarks being produced in pairs. The baryon number in Ω may have been transported from the incident nuclei and/or produced in the baryon-pair production of Ω with other types of anti-hyperons such as Ξ. To investigate these two scenarios, we propose to measure the correlations between Ω and K and between Ω and anti-hyperons. We use two versions, the default and string-melting, of a multiphase transport(AMPT) model to illustrate the method for measuring the correlation and to demonstrate the general shape of the correlation. We present the Ω-hadron correlations from simulated Au+Au collisions at ■ =7.7 and 14.6 Ge V and discuss the dependence on the collision energy and on the hadronization scheme in these two AMPT versions. These correlations can be used to explore the mechanism of baryon number transport and the effects of baryon number and strangeness conservation on nuclear collisions.
文摘The initial idea for baryonic acoustic oscillations (BAO) came about during early efforts to understand the origin of galaxies by studying perturbed versions of the Friedmann-Robertson-Walker (FRW) model. In more recent times, the emphasis has shifted to the idea that 2-point galaxy correlations embedded in the distribution of matter by the BAO could be used as a standard ruler to fix the parameters of cosmological models. In this paper, we first consider the actual business of extracting the correlation length from large data sets of measured galaxy locations. To facilitate this process, we introduce a much-improved method for extracting the correlation peak from the data set. Fundamental to this process in any model is the use of a fiducial cosmological model to transition from redshift space to comoving coordinate space where the correlations actually exist. The belief is that the correlation length so determined can then be reverted to redshift space to fix the parameters of cosmological models. We show, however, that this process is circular and hence of no value whatsoever for fixing model parameters. All one obtains are the parameters of the model used to transition to comoving space in the first place. Finally, we present simple arguments that show that the idea of BAO being responsible for the structure of the universe, i.e. the cosmic web, is unworkable.
文摘We propose a new description of a baryon as a pair of mesons. This description is an extension of the previously proposed description of a nucleon as a pair of pions. The purpose of this article is to show the following two possibilities. The first one is that it shows the qualitative explanation to support our description of a nucleon as a pair of pions and the second one is that it gives the systematic way of estimation of baryon mass not only for light baryons but also for heavy baryons (charm baryons and bottom baryons). Each isospin group is constructed of both baryons and antibaryons. This way of construction is consistent with that of mesons. The results obtained are listed in tables (Tables 1-9). This shows that the generalized Gell-Mann-Nishijima relation equation holds under the condition that the baryon number is 0 and that the obtained masses are fairly good, even for heavy baryons. Our description also yields several examples of baryon decay modes.
基金supported by the National Natural Science Foundation of China under Grants No.11905171 and No 12047502supported by the Natural Science Basic Research Plan in Shaanxi Province of China under Grant No.2022JQ-025。
文摘We study the masses of the doubly bottom baryons and the charmed-bottom baryons up to O(p^(3))in heavy baryon chiral perturbation theory.We determine the unknown low energy constants in the quark model and lattice QCD.We show the numerical results for the masses of the doubly bottom baryons and the charmed-bottom baryons up to O(p^(3)).
文摘This paper posits that the upward-going ANITA events are derived from the cosmic ray of the baryonic-dark matter (BDM) Higgs boson. In the extended standard model (ESM) for baryonic matter and dark matter, the spontaneous symmetry breaking through the Higgs mechanism for the symmetrical massless baryonic matter left-handed neutrinos and massless dark matter right-handed neutrinos produced massless baryonic matter left-handed neutrinos, sterile massive dark matter neutrinos, and the BDM Higgs boson. The BDM Higgs boson is the composite of the high-mass tau neutrino and the high-mass dark matter neutrino. During the passage through the high-density part of the Earth, the BDM Higgs boson is transformed into the oscillating BDM Higgs boson between the composite of the high-mass tau neutrino and the high-mass dark matter neutrino and the composite of the high-mass tau neutrino and the low-mass dark matter neutrino. The oscillating BDM Higgs boson decays into the high-mass tau neutrino with the extra energy and the low-mass dark matter neutrino (27 eV) in the low-density water-ice layer of the Earth. The high-mass tau neutrino is converted into ultra-high-energy tau neutrino which decays into tau lepton through the charged-current interactions, and tau lepton emerges from the surface of ice. Based on the periodic table of elementary particles, the calculated value for the high-mass tau neutrino with the extra energy is 0.47 EeV in good agreement with the observed 0.56 and 0.6 EeV. The periodic table of elementary particles for baryonic matter, dark matter, and gravity is based on the seven principal mass dimensional orbitals for stable baryonic matter leptons (electron and left-handed neutrinos), gauge bosons, gravity, and dark matter and the seven auxiliary mass dimensional orbitals for unstable leptons (muon and tau) and quarks, and calculates accurately the masses of all elementary particles and the cosmic rays by using only five known constants.
基金supported by the Foundation of the Guizhou Provincial Education Department of China under Grants No.KY[2016]104the National Natural Science Foundation of China under Grants Nos.11465011 and 11865018the Foundation of Guizhou Provincial Science and Technology of China under Grants No.J[2014]2150.
文摘In this letter,the cosmic distance-duality relation has been constrained with a model-independent method by combining the baryon acoustic oscillation(BAO)data and the type Ia supernova(SNe Ia)data.The results show that this relation is consistent with the observational data in the 68.27%error range,except for the instance of Union 2.1 plus BAO with the statistic errors only,where the relation is consistent with the observations in the 95.45%error range.To study the result of the uncertainty of the Hubble constant on the investigation of this relation,we treat the dimensionless Hubble constant h as a free parameter and get that the observational data favors the relation in the 68.27%error range.And then h has been marginalized and the results support that this relation is favored by the observations in the 68.27%error range too.
基金supported by National Natural Science Foundation of China(No.10975091)CCNU-QLPL Innovation Fund(QLPL2011P01)+1 种基金Excellent Youth Foundation of Hubei Scientific Committee(2006ABB036)Education Commission of Hubei Province of China(Z20081302)
文摘The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. The net-baryon distributions, nuclear stopping power and gluon saturation features in the SPS and RHIC energy regions are investigated by taking advantage of the gluon saturation model with geometric scaling. Predications are made for the net-baryon rapidity distributions, mean rapidity loss and gluon saturation features in central Pb ＋ Pb collisions at LHC.
文摘The exact solution of Sehrodinger equation corresponding to a baryonic system is the main interest in the present work. We take into account both quadratic and Coulomb terms in the potential relation. Next, after presenting an exact solution, we have calculated the spin and isospin effects in both ground and excited states. The results are comparable with experimental data.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11175093,11222545,11435006 and 11375092the K.C.Wong Magna Fund of Ningbo University
文摘We use the latest baryon acoustic oscillation and Union 2.1 type Ia supernova data to test the cosmic opacity between different redshift regions without assuming any cosmological models. It is found that the universe may be opaque between the redshift regions 0.35 0.44, 0.44 0.57 and 0.6-0.73 since the best fit values of cosmic opacity in these regions are positive, while a transparent universe is favored in the redshift region 0.57-0.63. However, in general, a transparent universe is still consistent with observations at the lo confidence level.
基金Supported by the National Natural Science Foundation of China (NSFC)by the CAS Key Projects KJCX2-yw-N29 and H92A0200S2
文摘In this work, we calculate the mass spectrum of doubly heavy baryons with the diquaxk model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquaxk field and a light quark field. Contributions of the operators up to dimension six are taken into account in the operator product expansion. Within a reasonable error tolerance, our numerical results axe compatible with other theoretical predictions. This indicates that the diquaxk picture reflects the reality and is applicable to the study of doubly heavy baryons.
基金The project supported by the Special Scientific Research Foundation for Doctoral Programs of Universities of China.
文摘Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are obtained in a unified manner. Our result shows that by employing either the △-mode or the Y-mode confining potential, one can achieve reasonable baryon spectra. The △-mode may be mostly effective for the short- and medium-distances, while the Y-mode may offer more contributions to the spectra for long-distances. Although the binding energies in baryon spectra may deviate by a few to several tens MeV for different modes, it is hard to determine either one to be dominant by simply evaluating the baryon spectra. One may need to invoke the baryon decay process to make further judgement.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11475257,11275268National University of Defense Technology Foundation under Grant No.JC14-02-05
文摘In the present work, the masses of the decuplet baryons at finite temperature are investigated using thermM QCD sum rules. Making use of the quark propagator at finite temperature, we caiculate the spectral functions to T8 order, and find that there are no contributions to the spectral functions at T8 order and the temperature corrections mainly come from that containing T4 ones. The calculations show very little temperature dependence of the masses below T =0.11 GeV. While above that vaJue, the masses decrease with increasing temperature. The results indicate that the hadron-quark phase transition temperature may be Tc ≥ 0.11 GeV for the decuplet bayons.
基金Supported by the National Natural Science Foundation of China(NNSFC)under Grant Nos.10975027,11275036,and 11047002
文摘Using the effective Hamiltonian method, we analyze the B0-B0 mixing in the extension of the standard model （SM） where baryon number and lepton number are local gauge symmetries. The numerical results indicate the correction from the extra particles to the mass difference ArnB is significant. There is a 60% enhancement compared to the SM prediction for AraB at most, which agrees with the current experimental result.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10975027,11275036,11047002Natural Science Fund of Hebei University under Grant Nos.2011JQ05 and 2012-242
文摘In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the parameter space, we find that the branching ratios of t →cγ and t →cg can reach 10^-6 and 10^-5 respectively, which can be detected in near future.
文摘From the equations of motion for baryons in the scalar strong interaction hadron theory (SSI), two coupled third order radial wave equations for baryon doublets have been derived and published in 1994. These equations are solved numerically here, using quark masses obtained from meson spectra and the masses of the neutron, ?0 and ?0 as input. Confined wave functions dependent upon the quark-diquark distance as well as the values of the four integration constants entering the quark-diquark interaction potential are found approximately. These approximative, zeroth order results are employed in a first order perturbational treatment of the equations of motion for baryons in SSI for free neutron decay. The predicted magnitude of neutron’s half life agrees with data. If the only free parameter is adjusted to produce the known A asymmetry coefficient, the predicted B asymmetry agrees well with data and vice versa. It is pointed out that angular momentum is not conserved in free neutron decay and that the weak coupling constant is detached from the much stronger fine structure constant of electromagnetic coupling.
文摘If most of the universe is made of baryons, we encounter a serious contradiction in explaining the observed structure formulation. Therefore, we need non-baryonic dark matter to comprise the universe. In a previous paper, the present author proposed an infinite sub-layer quark model in which there exists an infinite number of up quark <i>q<sub>u</sub></i> (∞) and down quark <i>q<sub>d</sub></i> (∞) at an infinite sub-layer level. These quarks have non-baryon quantum number with one-half electric charge. Thus, <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks are candidates for the non-baryonic dark matter. It is then shown that CP is violated only in the doublet of <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks to account for the asymmetry of the number of particles and anti-particles in the present universe. It should be emphasized that if the internal space of <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks in the first generation is a noncommutative geometry, CP violation can be explained without increasing the number of particles and generations. Thus, a pair of an infinite number of <i>q<sub>u</sub></i> (∞) and <i>q<sub>d</sub></i> (∞) quarks would be produced in the first moments after the Big Bang and form the hadrons including the nucleons and remain as the non-baryonic cold dark matter for all time. From the <i>q<sub>f</sub></i> (∞) quarks with the flavors <i>f</i> = <i>u</i>, <i>d</i>, <i>s</i>, <i>c</i>, <i>t</i>, and <i>b</i>, we compared our prediction value of the cross-section ratio <i>R</i> with the experimental values. We obtained the theoretical branching ratio <i>R</i> = 15/4 = 3.75 which is in good agreement with the experimental values from 12.00 GeV to 46.47 GeV in electron-positron annihilation into muon pairs and quark pairs.
基金The project supported by the Knowledge Innovation Project of the Chinese Academy of Sciences under Grant Nos.KJCX2-SW-N16 and KJCX3-SYW-N2National Natural Science Foundation of China under Grant Nos.10435080 and 10575123
文摘Baryon magnetic moments of p, n, ∑^＋,∑^-,Ξ^0, Ξ^- and the beta decay ratios （G A/Gv ） of n → p, ∑^-→n and Ξ^0→∑^＋ are calculated in a colored quark cluster model. With SU（3） breaking, the model gives a good fit to the experimental values of those baryon magnetic moments and the beta decay ratios. Our results show that the orbital motion has a significant contribution to the spin and magnetic moments of those baryons and the strange component in nucleon is small.
基金Supported by the National Natural Science Foundation of China under Grant No 11265014
文摘We study the ＇t Hooft coupling gt and the mass splitting of the ground-state baryons in terms of the large Noinspired quark model, by which the Hartree wavefunctions of light quarks are obtained. By fitting the spectra of decuplet and octet baryons, we obtain the ＇t Hooft coupling gt to be around 1.57. We generalize the scenario to the case of heavy baryons, such as Ac, gt values which does not deviate much from 1.57, as well as to the case of mesons with 9t far from that for baryons. The consequence is discussed.
基金The project supported by National Natural Science Foundation of China
文摘In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams are also included. The hadronic matrix elements are evaluated in the simple non-relativistic harmonic oscillator model. Our numerical results are generally consistent with that obtained by other authors who used the diquark model. However, all the theoretical predictions on the lifetimes are one order larger than the upper limit set by the recent SELEX measurement. This discrepancy would be clarified by the future experiment. If more accurate experiment still confirms the value of the SELEX collaboration, there must be some unknown mechanism to be explored.
