Strong Decays of Charm Mesons D1*(2680), D3*(2760), D2*(3000)

In this article, we assign the higher charm mesons D₁^*(2680), D₃^*(2760) and D₂^*(3000) to be the 2S 1^-, 1D 3^- and 1F 2⁺ states, respectively, and study the two-body strong decays to the ground state charm mesons and light pseudoscalar mesons with the heavy meson effective theory. We obtain the ratios among the strong decays, which can be confronted to the experimental data in the future and shed light on the nature of those higher charm mesons.     

Systematic analysis of D_J(2580), D_J~*(2650), D_J(2740), D_J~*(2760),D_J(3000) and D_J~*(3000) in the D meson family

In this work, we tentatively assign the charmed mesons D J(2580), D*J(2650), D J(2740), D*J(2760),D J(3000) and D*J(3000) observed by the LHCb collaboration according to their spin, parity and masses, then systematically study their strong decays to ground state charmed mesons plus pseudoscalar mesons with the3P0 decay model. Based on these studies, we assign the D*J(2760) as the 1D5/23-state, the D*J(3000) as the 1F5/22+or 1F7/24+state, the D J(3000) as the 1F7/23+or 2P1/21+state in the D meson family. As a byproduct, we also study the strong decays of the states 2P1/20+, 2P3/22+, 3S1/21-, 3S1/20-etc, which will be valuable in searching for the partners of these D mesons.     

Production of P-wave charm and charm-strange mesons in hadronic Z0 decays

Results are presented on the production of excited charm and excited charm-strange mesons in hadronic Z⁰ decays. The results are obtained from approximately 4.3 million hadronic Z⁰ decays, collected on or near the Z⁰ resonance using the OPAL detector at LEP. The D⁰ ₁(2420) and D^*0 ₂ (2460) mesons are reconstructed in the D^*+π^-. final state and their separate production rates in charm fragmentation and in weak decays of b-hadrons are determined. Assuming that the decay widths of these mesons are saturated by the allowed D*π and Dπ final states, the charm hadronization fractions and the inclusive branching ratios of b-hadrons to these neutral P-wave charm mesons are determined to be     

Hadron molecules

We discuss a possible interpretation of the open charm mesons D*s0 (2317),D s1 (2460) and the hidden charm mesons X(3872),Y(3940) and Y(4140) as hadron molecules.Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D* s0 (2317) and D s1 (2460) states.The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration.Determing the radiative (γJ/ψ and γψ(2s)) and strong (J/ψ2π and J/ψ3π) decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X(3872).Finally,we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes J/ψ+ω or J/ψ+φ,respectively.     

Possible heavy molecular states composed of a pair of excited charm-strange mesons

The P-wave charm-strange mesons Ds0(2317) and Ds1(2460) lie below the DK and D*K threshold respectively. They are extremely narrow because their strong decays violate the isospin symmetry. We study the possible heavy molecular states composed of a pair of excited charm strange mesons. As a byproduct, we also present the numerical results for the bottonium-like analogue.     

Possible heavy molecular states composed of a pair of excited charm-strange mesons

The P-wave charm-strange mesons D_s0(2317) and D_s1(2460) lie below the DK and D^* K threshold respectively. They are extremely narrow because their strong decays violate the isospin symmetry. We study the possible heavy molecular states composed of a pair of excited charm strange mesons. As a byproduct, we also present the numerical results for the bottonium-like analogue.     

Analysis of the Possible $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ Molecules with QCD Sum Rules *

In this article, we assume that there exist the pseudoscalar $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ molecular states $Z_{1,2}$ and construct the color singlet-singlet molecule-type interpolating currents to study their masses with the QCD sum rules. In calculations, we consider the contributions of the vacuum condensates up to dimension-10 and use the formula $\mu=\sqrt{M_{X/Y/Z}^{2}-(2{\mathbb{M}}_{c})^{2}}$ to determine the energy scales of the QCD spectral densities. The numerical results, $M_{Z_1}=4.61_{-0.08}^{+0.11}\,\text{GeV}$ and $M_{Z_2}=4.60_{-0.06}^{+0.07}\,\text{GeV}$, which lie above the $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ thresholds respectively, indicate that the $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ are difficult to form bound state molecular states, the $Z_{1,2}$ are probably resonance states.     

B→K_0~*(1430)η~(') decays in the pQCD approach

Based on the assumption of two-quark structure of the scalar meson K*0(1430),we calculate the CP-averaged branching ratios for B→K0*(1430)η(') decays in the framework of the perturbative QCD(pQCD) approach here.We perform the evaluations in two scenarios for the scalar meson spectrum.We find that:(a) the pQCD predictions for Br(B→K*0(1430)η(')) which are about 10-5-10-6,basically agree with the data within large theoretical uncertainty;(b) the agreement between the pQCD predictions and the data in Scenario I is better than that in Scenario II,which can be tested by the forthcoming LHC experiments;(c) the annihilation contributions play an important role for these considered decays.     

Analysis of the excited bottom and bottom-strange states B1（5721）, B2*（5747）,Bs1（5830）, Bs2*（5840）, BJ（5840） and BJ（5970） of the B meson family

In order to make a further confirmation of the assignments of the excited bottom and bottom-strange mesons B1(5721),B2^*(5747),Bs1(5830)and Bs2^*(5840)and identify possible assignments of BJ(5840)and BJ(5970),we study the strong decay of these states with the 3P0 decay model.Our analysis supports the assignments of B1(5721)and B2*(5747)as the 1P'1 and 1^3P2 states,and Bs1(5830)and Bs2^*(5840)as the strange partners of B1(5721)and B2^*(5747).Besides,we tentatively identify the recently observed BJ(5840)and BJ(5970)as the 2^3S1 and 13D3 states.It is noted that these conclusions need further confirmation by measurements of the decay channels BJ(5840)→Bπand BJ(5970)→Bπ.     

DsJ(2860) as the first radial excitation of Ds0*(2317)

A coupled-channel model previously employed to describe the narrow Ds0*(2317) and broad D0*(2400) charmed scalar mesons is generalized so as to include all ground-state pseudoscalar-pseudoscalar and vector-vector two-meson channels. All parameters are chosen fixed at published values, except for the overall coupling constant, which is fine-tuned to reproduce the Ds0*(2317) mass. Thus, the radial excitations Ds0*(2850) and D0*(2740) are predicted, both with a width of about 50 MeV. The former state appears to correspond to the new DsJ(2860) resonance decaying to DK announced by BABAR in the course of this work. Also, the D0*(2400) resonance is roughly reproduced, though perhaps with a somewhat too low central resonance peak.     

D* D_1(2420) and D D'*(2600) interactions and the charged charmonium-like state Z(4430)

The D* D_1(2420) and DD '*(2600) interactions are studied in a one-boson-exchange model. Isovector bound state solutions with spin parity J~P= 1~+are found from the D* D_1(2420) interaction, which may be related to the observed charged charmonium-like state Z(4430). There is no bound state solution found from the DD '*(2600)interaction.     

Production of orbitally excited charm mesons in semileptonic B decays

A sample of 3.6 million hadronic Z decays recorded between 1991 and 1995 with the ALEPH detector at LEP is used to investigate semileptonic decays of B mesons into final states involving orbitally excited charm mesons. Topological vertex criteria are used to search for decays involving narrow D** states as well as wide D** resonances and non-resonant D(*)π final states. The sum of the branching ratios for these processes is measured to be ${? Br}({?erline {? B}}?ghtarrow {? D}? ?l^{-}{?erline v}) + {? Br}({?erline {? B}}?ghtarrow {? D}^{?t}? ?l^{-}{?erline v})?op =(2.26 pm 0.29({? stat}) pm 0.33({? syst}))%,$which accounts for a significant fraction of the deficit between inclusive measurements and the sum of exclusive semileptonic B decay modes.     

Nonfactorizable contributions to charm meson (D→ PP) decays

Two-body weak decays of charm mesons into two pseudoscalar mesons are examined employing SU(3) flavor symmetry for the non-factorizable matrix elements. Using certain measured Cabibbo-favored modes, we fix the reduced matrix elements and predict the branching ratios of the Cabibbo-angle suppressed and doubly-suppressed decays of D and D _s mesons.     

Chiral effective Lagrangian for excited heavy-light mesons from QCD

We derive the chiral effective Lagrangian for excited heavy-light mesons from QCD under proper approximations. We focus on the chiral partners with j_l~P=3+/2 and j_l~P=3~-/2 which amounts to(1~+, 2~+) and(1~-, 2~-) states respectively. The low energy constants including the masses of the chiral partners are calculated. The calculated spectrum for the excited mesons are found roughly consistent with experimental data. In addition, our results indicate that quantum numbers of B_J(5970) can be identified with 1~-or 2~-.     

Dynamics of strong and radiative decays of Ds-mesons in the hadrogenesis conjecture

The positive parity scalar D*s0(2317) and axial-vector D*s1(2460) charmed strange mesons are generated by coupled-channel dynamics through the s-wave scattering of Goldstone bosons off the pseudoscalar and vector D(Ds)-meson ground states. The specific masses of these states are obtained as a consequence of the attraction arising from the Weinberg-Tomozawa interaction in the chiral Lagrangian. Chiral corrections to order Q2χ are calculated and found to be small. The D*s0(2317) and D*s1(2460) mesons decay either strongly into the isospin-violating π0Ds and π0D*s channels or electromagnetically. We show that the π0-η and (K0D+-K+D0) mixings act constructively to generate strong widths of the order of 140 keV and emphasize the sensitivity of this value to the KD component of the states. The one-loop contribution to the radiative decay amplitudes of scalar and axial-vector states is calculated using the electromagnetic Lagrangian to chiral order Q2χ. We show the importance of taking into account processes involving light vector mesons explicitly in the dynamics of electromagnetic decays. The radiative width are sensitive to both η Ds and KD components, hence providing information complementary to the strong widths on the positive parity Ds-meson structure.     

A static calculation of radiative decay widths of mesons in a potential model of independent quarks

Taking a relativistic potential model of independent quarks with its parameters determined from a fit to the mass splittings of ground state mesons in the strange, charm and bottom flavor sector, we perform a ‘static’ calculation of decay widths for the radiative transitions of mesons within the conventional picture of photon emission by a confined quark and/or antiquark. The results obtained in most of the cases of light mesons are in an overall agreement with the experimental values. The predictions in heavy meson decays are comparable to those of other model calculations.     

Charm hadronic decays and quantum correlations at CLEO-c

Several recent CLEO-c results on hadronic decays of charm mesons are reviewed.Topics include measurements of precision branching fractions for exclusive modes,investigations of inclusive rates,and analyses of Dalitz plots.In addition,the quantum correlations of the D pairs produced at the ψ(3770) are exploited to measure phase information that is of current interest for both D and B physics.     

Z~+(4430) and Analogous Heavy Flavor States

We have studied Z~+ (4430)as a D~* D_1 molecule from the quark model,state mixing effect is considered by solving the coupled channel Schr(o)dinger equation numerically.More precise measurements of Z~+ (4430)mass and width,partial wave analysis are helpful to understand its structure.If it lies below the D~* D_1 threshold,molecule interpretation with J~P=1~- is favored,and JP =0~- can not be ruled out.Otherwise Z~+ (4430)may be a virtual state with J~P=2~-.The analogous heavy flavor mesons Z~+_(bb) and Z~(++)_(bc) are considered as well,and the masses predicted in our model are in agreement with the predictions from the potential model and QCD sum rule.