arXiv subjects
Publications and source records attributed to Yubing Dong.
The isotriplet Sigmac(2800) baryon with possible quantum numbers J(P) = 1/2(+), 1/2(-) or 3/2(+), 3/2(-) is considered as a hadronic molecule composed of a nucleon and a D meson. We determine the strong two-body decay widths Sigmac to Lambdac + pi which are shown to be consistent with current data for the J(P) = 1/2(+) and J(P) = 3/2(-) assignments.
The Lambdac(2940)+ baryon with possible quantum numbers J(P) = 1/2+ and 1/2- is studied as a molecular state composed of a nucleon and D* meson. We give predictions for the strong two-body decay channels Lambdac(2940)+ to p D0, Sigmac(++) pi(-) and Sigmac(0) pi(+) where the sum of partial widths is consistent with current data for the case of J(P) = 1/2(+). The case of J(P) = 1/2(-) is shown to be ruled out.
The X(3872) with quantum numbers J(PC) = 1(++) is considered as a composite hadronic state comprised of the dominant molecular D(0) D*(0) component and other hadronic pairs - D(+-) D*(-+), Jpsi omega and Jpsi rho. Applying the compositeness condition we constrain the couplings of the X(3872) to its constituents. We calculate two- and three-body hadronic decays of the X(3872) to charmonium states chi(cJ) and pions using a phenomenological Lagrangian approach. Next using the estimated X-Jpsi-omega and and X-Jpsi-rho couplings we calculate the widths of X(3872) to Jpsi + h, where h = pi(+) pi(-), pi(+) pi(-) pi(0), pi(0) gamma and gamma. The obtained results for the decay pattern of the X(3872) in a molecular interpretation could be useful for running and planned experiments.
A phenomenological Lagrangian approach is employed to study the electromagnetic properties of the deuteron. The deuteron is regarded as a weakly bound state of the proton and neutron. We construct a general form for the electromagnetic one- and two-body transition operators formulated in terms of the nucleon fields, which are then used in the calculation of the electromagnetic deuteron form factors. One of the two-body operators is responsible for explaining the quadrupole moment form factor. We show that in our approach the data on the deuteron form factors as well as on the differential cross section of elastic electron-deuteron scattering are well explained.
The X(3872) resonance is considered as a hadronic molecule, a loosely-bound state of charmed D0 and D*0 mesons, since its mass is very close to the D*0 barD0 threshold. Assuming structure and quantum numbers of X(3872) as (D0 barD*0 - D*0 barD0)/sqrt(2) and J(PC) = 1(++), we calculate the X(3872) to gamma J/psi decay using a phenomenological Lagrangian approach. We also estimate the contribution of an additional c bar(c) component in the X(3872) to this decay width, which is shown to be suppressed relative to the one of the molecular configuration.
A longitudinal transition operator that satisfies the gauge invariance requirement is introduced in constituent quark model. The corresponding longitudinal transitions between the nucleon and baryon resonances are calculated. We show that the study of the longitudinal coupling plays an important role in understanding the structure of baryons.