Lifetime of Doubly Charmed Baryons

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.     

$J^{P}$ Assignments of $\Lambda_c^{+}$ Baryons

The ＂good＂ diquark is employed to study A＋ baryons within a mass loaded flux tube model. The study indicates that all A＋ baryons candidates in the 2008 review by the Particle Data Group （PDG） are well described in the mass loaded flux model. The quantum numbers JP of these A＋ candidates are assigned. If Ac（2765）＋ is an orbitally excited A＋, it is likely the JP=3/2＋one. If ∧c（2765）＋ is an orbitally excited ∑c, there ought to be another JP=3/2＋∧c＋with mass ≈2770 MeV. In the model, there exists no JP=1/2＋∧c＋（≈2700）predicted in existing literature. Ac （2940）＋ is very possible the orbitally excited baryon with     

Charmed baryon magnetic moments in the covariant oscillator quark model with isospin symmetry breaking

The magnetic moments of charmed baryons are studied in the covariant oscillator quark model including isospin symmetry breaking effect. In the uncharmed sector, the results differ from those obtained using conventional non-relativistic quark model (nrqm). But in the charmed sector the present values are much nearer to thenrqm results than those calculated using models with hadron mass dependence.     

Quark-diquark model description for double charm baryons

We report here the mass spectrum and magnetic moments of ccq（q ∈ u,d,s） systems in the potential model framework by assuming the inter-quark potential as the colour coulomb plus power form with power index ν varying between 0.1 to 2.0.Here the two charm quarks are considered for the diquark states.The conventional one gluon exchange interaction has been employed to get the hyperfine and the fine structure between different states.We have predicted many low-lying states whose experimental verification can exclusively support the quark-diquark structure of the baryons.     

Non-leptonic weak decays of charmed baryons

It is shown that the ΔC _h=ΔS decays of a baryon sextuplet, triplet and singlet of SU (3), into meson and baryon, can provide simple tests of the iscspin and SU (3) transformation properties of the ΔC _h=ΔS non-leptonic interaction in the Glashow Iliopoulos-Maiani scheme.     

Quark-diquark model description for double charm baryons

We report here the mass spectrum and magnetic moments of ccq(q ∈ u,d,s) systems in the potential model framework by assuming the inter-quark potential as the colour coulomb plus power form with power index ν varying between 0.1 to 2.0.Here the two charm quarks are considered for the diquark states.The conventional one gluon exchange interaction has been employed to get the hyperfine and the fine structure between different states.We have predicted many low-lying states whose experimental verification can exclusively support the quark-diquark structure of the baryons.     

Spectra of charmed and bottom baryons with hyperfine interaction

Up to now,the excited charmed and bottom baryon states have still not been well studied experimentally or theoretically.In this paper,we predict the mass of ?*b,the only L=0 baryon state which has not been observed,to be 6069.2 Me V.The spectra of charmed and bottom baryons with the orbital angular momentum L = 1 are studied in two popular constituent quark models,the Goldstone boson exchange(GBE) model and the one gluon exchange(OGE) hyperfine interaction model.Inserting the latest experimental data from the "Review of Particle Physics",we find that in the GBE model,there exist some multiplets(Σc(b),Ξ c(b)and ?c(b)) in which the total spin of the three quarks in their lowest energy states is 3/2,but in the OGE model there is no such phenomenon.This is the most important difference between the GBE and OGE models.These results can be tested in the near future.We suggest more efforts to study the excited charmed and bottom baryons both theoretically and experimentally,not only for the abundance of baryon spectra,but also for determining which hyperfine interaction model best describes nature.     

Charmed baryons in a relativistic quark model

We calculate mass spectra of charmed baryons within a relativistically covariant quark model based on the Bethe-Salpeter equation in instantaneous approximation. Interactions are given by a linearly rising three-body confinement potential and a flavor-dependent two-body force derived from QCD instanton effects. This model has already been successfully applied to the calculation of light flavor baryon spectra and is now extended to heavy baryons. Within the same framework we compare the results to those obtained with the more conventional one-gluon exchange potential.     

Magnetic moments of baryons in broken SU(4)

Assuming that the anomalous magnetic moment interaction has the formaT ₁ ¹ +bT ₂ ² +cT ₄ ⁴ +sT _α ^α in SU(4), which may arise due to symmetry breaking or some other dynamical effects, we have obtained the magnetic moments and the transition moments of the ordinary and charmed baryons.     

Charmed hadrons in nuclear medium

We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner.We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions.We discuss the implications of the in-medium properties of open-charm mesons on the D s0 （2317） and the predicted X（3700） scalar resonances.     

Charmed hadrons in nuclear medium

We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions. We discuss the implications of the in-medium properties of open-charm mesons on the DsO(2317) and the predicted X(3700) scalar resonances.     

Triply heavy baryons in the constituent quark model

The constituent quark model is used to compute the ground and excited state masses of QQQ baryons containing either c or b quarks.The quark model parameters previously used to describe the properties of charmonium and bottomonium states were used in this analysis.The non-relativistic three-body bound state problem is solved by means of the Gaussian expansion method which provides sufficient accuracy and simplifies the subsequent evaluation of the matrix elements.Several low-lying states with quantum numbers J^P=1/2^±,3/2^±,5/2^±and 7/2^+are reported.We compare the results with those obtained by the other theoretical formalisms.There is a general agreement for the mass of the ground state in each sector of triply heavy baryons.However,the situation is more puzzling for the excited states,and appropriate comments about the most relevant features of our comparison are given.     

D→PP衰变过程的末态相互作用

利用单粒子交换方法,研究了D介子衰变到两个赝标粒子中的末态相互作用.通过实验数据中抽取的强相角来分析末态相互作用的效应     

Baryon magnetic moments in a quark model

The magnetic moments of uncharmed and charmed baryons are considered to arise through single-quark and two-quark transitions in a quark model. The magnetic moment operator is taken to transform as:T _β ^α ˜aT ₁ ¹ , +bT ₂ ² +cT ₃ ³ +dT ₄ ⁴ , whereT _β ^α are members of SU(4)20′-plet. The assumption, that the magnetic moment operator obtains contribution from the single and two-quark transitions, yields good results for the magnetic moment values of uncharmed baryons. Magnetic moments of charmed baryons can be expressed in terms of one parameter.     

J~P assignments of Λ_c~+ baryons

The "good" diquark is employed to study Λ_c~+ baryons within a mass loaded flux tube model. The study indicates that all Λ_c~+ baryons candidates in the 2008 review by the Particle Data Group (PDG) are well described in the mass loaded flux model. The quantum numbers J~P of these Λ_c~+ candidates are assigned. If Λ_c(2765)~+ is an orbitally excited Λ_c~+, it is likely the J~P=3~+/2 one. If Λ_c(2765)~+ is an orbitally excited Σ_c, there ought to be another J~P = 3~+/2 Λ_c~+ with mass ≈ 2770 MeV. In the model, there exists no J~P = 1~+/2 Λ_c~+ (≈ 2700) predicted in existing literature. Λ_c(2940)~+ is very possible the orbitally excited baryon with J~P = 5~-/2.     

Charmed Meson Production in Deep Inelastice+A Scattering at Small-x

Based on the nuclear effects considered in the Glauber-Gribov approach, charmed meson production in high energy deep inelastic e+A scattering is investigated in the color dipole formalism. Using the Peterson fragmentation function and the KLR-AdS/CFT color dipole model, which reasonably well describes the HERA data for the inclusive structure functions at small Bjorken-x, we present the predictive results for the D-meson transverse spectra at EIC and LHeC energies. The theoretical results indicate that the $x$-independence phenomena at very small-x predicted by the KLR-AdS/CFT model are not seen in our calculation.