We calculate the two-body strong decays of the orbitally excited scalar mesons $D_0^*(2400)$ and $D_J^*(3000)$ by using the relativistic Bethe-Salpeter (BS) method. $D_J^*(3000)$ was observed recently by the LHCb Collaboration, the quantum number of which has not been determined yet. In this paper, we assume that it is the $0^+(2P)$ state and obtain the transition amplitude by using the PCAC relation, low-energy theorem and effective Lagrangian method. For the $1P$ state, the total widths of $D_0^*(2400)^{0}$ and $ D_0^*(2400)^+$ are 226 MeV and 246 MeV, respectively. With the assumption of $0^+(2P)$ state, the widths of $D_J^*(3000)^0$ and $D_J^*(3000)^+$ are both about 131 MeV, which is close to the present experimental data. Therefore, $D_J^*(3000)$ is a strong candidate for the $2^3P_0$ state.
Exclusive semileptonic B meson decays to orbitally excited D mesons are investigated in the infinitely heavy quark limit in the framework of the relativistic quark model based on the quasipotential approach. The B\to D^{**}eνIsgur-Wise functions τ_{3/2}(w) and τ_{1/2}(w) are determined. It is found that the relativistic transformation of the meson wave functions (Wigner rotation of the light quark spin) contribute already at the leading order of the heavy quark expansion.
Orbitally excited heavy-light mesons are potentially important as tools for tagging the flavors and momenta of ground-state pseudoscalars detected through weak decays. We use heavy-quark symmetry supplemented by insights gleaned from potential models to estimate masses and widths of $p$-wave $B$, $B_s$, and $D_s$ mesons. We generalize these results to higher excitations.
The mass spectrum of orbitally and radially excited states of B and D mesons is calculated in the framework of the relativistic quark model. The expansion in inverse powers of the heavy quark mass is carried out up to the first order, while the light quark is treated without expansion. We find that the relativistic treatment of the light quark plays an important role. Different patterns of P level inversion are discussed. The obtained masses of orbitally and radially excited states are in accord with available experimental data and heavy quark symmetry relations.
The BaBar Collaboration has recently reported branching fractions for semileptonic decays of the $B$ meson into final states with charged and neutral $D_{1}(2420)$ and $D_{2}^{\ast}(2460)$, two narrow orbitally excited charmed mesons. We evaluate these branching fractions within the framework of a constituent quark model in two steps, one which involves a semileptonic decay and the other one mediated by a strong process. Our results are in agreement with the experimental data.
A new Regge-like mass relation for excited light mesons is presented in relativized quark model which supports an universality that the quark mass dependence of the light meson spectroscopy is suppressed significantly and the confining parameter is nearly family independent. It is obtained by using auxiliary field method and quasi-linearizing the solution to the mass relation solved from the model. The resulted mass predictions are in good agreement with the observed masses for the orbitally-excited trajectory family of $π/b$, $ρ/a$, $η/h$, $ω/f$, $K^{\ast}$ and $ϕ/f^{\prime}$. A semiclassical…
In this paper we compute, within in the context of a relativistic quark model, the Isgur-Wise functions for exclusive semileptonic $\bar B \to X_c$ decays, where $X_c$ is any charmed mesons with total spin $J=0,1,2$ or one of their first excited states. The relevant matrix elements are computed by a direct numerical integration, in coordinate space, of the convolution of the wave function of the $B$ meson at rest and the wave function of the $X_c$ meson, boosted according with its recoil factor. Our results are compared with other predictions found in the existing literature.
The transition form factors of the semileptonic $B \rightarrow D_2^*(2460)\ell\barν\,\,\,\,(\ell=τ,μ,e)$ decay channel are calculated within the framework of the three-point QCD sum rules. The fit functions of the form factors are then used to estimate the total decay width and branching ratio of this transition. The order of branching ratio shows that this channel can be detected at LHCb.
We present the first phenomenological study of the masses of orbitally excited baryons in large N_c QCD. Restricting here to the nonstrange sector of the L=1 baryons, the 1/N_c expansion is used to order and select a basis of effective operators that spans the nine observables (seven masses and two mixing angles). Fits are performed using subsets of the complete set of nine operators, including corrections up to O(1/N_c) where leading order is N_c^1. This study shows that the 1/N_c expansion provides an excellent framework for analyzing the mass spectrum, and uncovers a new hierarchy of operat…
The complete spectrum of $c\bar{b}$ states is obtained in a phenomenological non relativistic quark model(NRQM), which consists of a confinement potential and one gluon exchange potential (OGEP) as effective quark - antiquark potential. We make predictions for the radiative decay (E1 and M1) widths and weak decay widths of $c\bar{b}$ states in the framework of NRQM formalism.
In this letter we discuss the masses and the splittings of 1(2S+1)P_J states in the spectrum of D and B mesons, as they appear in the approach of the QCD string with quarks at the ends. We find good agreement of our predictions with those of other QCD-motivated models as well as with the lattice and experimental data, including recent experimental results. We discuss the ordering pattern for P levels in D- and B-mesonic spectrum.
The mass and residues of the first radial and orbital excitations of $J=\frac{1}{2}$ baryons containing two heavy quarks (b or c) are calculated within the QCD sum rules method. In calculations, the general forms of the interpolating currents with symmetric and anti-symmetric forms with respect to the exchange of heavy quarks have been used. Our results on the spectroscopic parameters of doubly heavy baryons are compared with the predictions of other theoretical approaches.
Meson mass spectra, evaluated in the framework of the relativistic model of quasi-independent quarks, are presented. Mass values are obtained with the help of numerical calculations based on the Dirac equation and by phenomenological mass formulae. The Dirac equation involves the potential, which is sum of the vector quasi-Coulombic potential and the scalar linear rising confinement potential. The phenomenological mass formulae are applied to excited meson states consisting of u-, d-quarks and antiquarks with isotopical spin I=1. A comparison of the evaluated mass spectra with existing data is…
Within the k_t-factorization framework, we study diffractive production of orbitally excited vector mesons and compare it with the production of radial excitations, focusing on the rho(1450)/rho(1700) case. At small Q^2, orbital excitation of light quarkonia is found to dominate over radial excitations in diffractive production. We predict strong suppression of the production of orbital excitations by longitudinal photons, which leads to very small sigma_L/sigma_T ratio. At small Q^2, the s-channel helicity violating transitions contribute \sim 10-15% of the transverse cross section and \sim 5…
The rare processes $B_c\to D_{(s)J} ^{(*)}μ\barμ$, where $D_{(s)J}^{(*)}$ stands for the final meson $D_{s0}^*(2317)$, $D_{s1}(2460,2536)$,~$D_{s2}^*(2573)$, $D_0^*(2400)$, $D_{1}(2420,2430)$ or~$D_{2}^*(2460)$, are studied within the Standard Model. The hadronic matrix elements are evaluated in the Bethe-Salpeter approach and furthermore a discussion on the gauge-invariant condition of the annihilation hadronic currents is presented. Considering the penguin, box, annihilation, color-favored cascade and color-suppressed cascade contributions, the observables $\text{d}Br/\text{d}Q^2$, $A_{LPL}$…
The form factors of weak decays of the B meson to orbitally excited scalar, axial vector and tensor light mesons are calculated in the framework of the QCD-motivated relativistic quark model based on the quasipotential approach. Relativistic effects are systematically taken into account. The form factors are expressed trough the overlap integrals of the meson wave functions and their dependence on the momentum transfer is selfconsistently determined in the whole kinematical range. On this basis semileptonic and two-body nonleptonic B decay rates to orbitally excited light mesons are calculated…
The form factors of weak decays of the B_c meson to orbitally excited charmonium, D, B_s and B mesons are calculated in the framework of the QCD-motivated relativistic quark model based on the quasipotential approach. Relativistic effects are systematically taken into account. The form factor dependence on the momentum transfer is reliably determined in the whole kinematical range. The form factors are expressed trough the overlap integrals of the meson wave functions which are known from the previous mass spectra calculations within the same model. On this basis semileptonic and nonleptonic B…
We re-investigate the effects of the $1/m_c$ corrections on the spectrum of the lowest orbitally excited $D$-meson states. We argue that one should expect the $1/m_c$ corrections to induce a significant mixing between the two lowest lying $1^+$ states. We discuss the implications of this mixing and compute its effect on the semileptonic decays $B \to D^{**} \ell \barν$ and the strong $D^{**}$ decays.
Relativistic properties of qqbar potentail, mass spectra of orbitally and radially excited B and D mesons as well as semileptonic decays of B mesons to orbitally excited D mesons are discussed in the framework of the relativistic quark model based on the quasipotential approach.
We have obtained the differential decay rate and calculated the branching ratios of the exclusive semileptonic decays $B(D) \to Xlν$, where $X$ is a p-wave meson, using the nonrelativistic ISGW quark model. Our results are compared with the predictions of the ISGW2 model. We have computed some branching ratios that were not reported or were reported with 0.00 in this model. For example, we find that $Br(B_c^- \to \bar{B_{s2}^{*0}}l^-\barν) = 4.03 \times 10^{-5}$, $Br(B_c^- \to \bar{B_2^{*0}}l^- \barν) =3.65 \times 10^{-6}$ and $Br(D_s^+ \to f_2l^+ν) = 2.7 \times 10^{-5}$, which seems to be at …
The exclusive rare radiative B meson decay to the orbitally excited tensor K_2^*(1430) meson is investigated in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. The calculated branching ratio BR(B --> K_2^*(1430)γ)=(1.7\pm 0.6)\times 10^{-5} as well as the ratio BR(B --> K_2^*(1430)γ)/BR(B --> K^*(892)γ)=0.38\pm 0.08 is found in a good agreement with recent experimental data from CLEO.
The BaBar Collaboration has recently reported products of branching fractions that include $B$ meson semileptonic decays into final states with charged and neutral $D_{1}(2420)$ and $D_{2}^{\ast}(2460)$, two narrow orbitally excited charmed mesons. We evaluate these branching fractions, together with those concerning $D_{0}^{\ast}(2400)$ and $D_{1}'(2430)$ mesons, within the framework of a constituent quark model. The calculation is performed in two steps, one of which involves a semileptonic decay and the other is mediated by a strong process. Our results are in agreement with the experimenta…
Once chosen the dynamics in one frame, the rest frame in this paper, the Bakamjian and Thomas method allows to define relativistic quark models in any frame. These models have been shown to provide, in the infinite quark mass limit, fully covariant current form factors as matrix elements of the quark current operator. In this paper we use the rest frame dynamics fitted from the meson spectrum by various authors, already shown to provide a reasonable value for $ρ^2$. From the general formulae for the scaling invariant form factors $ξ^{(n)}(w)$, $τ_{1/2}^{(n)}(w)$ and $τ_{3/2}^{(n)}(w)$, we pred…
The discussion of the 70-plet of negative parity baryons illustrates the large Nc QCD approach to orbitally excited baryons. In the case of the l=1 baryons the existing data allows to make numerous predictions to first order in the SU(3) symmetry breaking. New relations between splittings are found that follow from the spin-flavor symmetry breaking. The Lambda(1405) is well described as a three-quark state and a spin-orbit partner of the Lambda(1520). Singlet states with higher orbital angular momentum are briefly discussed.
We discuss in general the construction of gauge-invariant non-local meson operators on the lattice. We use such operators to study the $P$- and $D$-wave mesons as well as hybrid mesons in quenched QCD, with quark masses near the strange quark mass. The resulting spectra are compared with experiment for the orbital excitations. For the states produced by gluonic excitations (hybrid mesons) we find evidence of mixing for non-exotic quantum numbers. We give predictions for masses of the spin-exotic hybrid mesons with $J^{PC}=1^{-+},\ 0^{+-}$, and $2^{+-}$.
The exclusive rare radiative B meson decays to orbitally excited axial-vector mesons K_1^*(1270), K_1(1400) and to the tensor meson K_2^*(1430) are investigated in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. These decays are considered without employing the heavy quark expansion for the s quark. Instead the s quark is treated to be light and the expansion in inverse powers of the large recoil momentum of the final K^{**} meson is used to simplify calculations. It is found that the ratio of the branching fractions of rare radiative…
$b \to c$ semileptonic sum rule: orbitally excited hadrons
KEK Theory Center, IPNS, KEK（高能加速器研究机构理论中心）；Graduate Institute for Advanced Studies, SOKENDAI（日本综合研究大学院大学高等研究院）；Institute for Advanced Research (IAR), Nagoya University（名古屋大学先进研究院）；Kobayashi-Maskawa Institute (KMI) for the Origin of Particles and the Universe, Nagoya University（名古屋大学小林-益川粒子与宇宙起源研究所）；Department of Liberal Arts, Saitama Medical University（埼玉医科大学通识教育部）
研究$b\to c τ\overline{ν}$过渡中涉及轨道激发的重子的半轻子求和规则，探讨偏离小速度极限的现象，指出激发强子导致偏差增大，但相关形式因子尚不充分约束。
Possible assignments of $D_{s1}(2700)^\pm$ and $D_{sJ}(2860)$ in the conventional quark model are analyzed. The study indicates that both the orbitally excited $c\bar s$ and the radially excited $c\bar s$ are possible. Some implications to these assignments are explored. If $D_{s1}(2700)^\pm$ and $D_{sJ}(2860)$ are the orbitally excited D-wave $1^- (j^P={3\over 2}^-)$ and $3^- (j^P={5\over 2}^-)$, respectively, another orbitally excited D-wave $2^-$ $D_s$, $D_{s2}(2800)$, is expected. If $D_{s1}(2700)^\pm$ and $D_{sJ}(2860)$ are the first radially excited $1^- (j^P={1\over 2}^-)$ and $0^+ (j^P…
We calculate the masses and the strong decays of orbitally excited states $B_{s0}$, $B'_{s1}$, $B_{s1}$ and $B_{s2}$ by the improved Bethe-Salpeter method. The predicted masses of $B_{s0}$ and $B'_{s1}$ are $M_{B_{s0}}=5.723\pm0.280 {\rm GeV}$, $M_{B'_{s1}}=5.774\pm0.330 {\rm GeV}$. We calculate the isospin symmetry violating decay processes $B_{s0}\to B_s π$ and $B'_{s1}\to B_s^* π$ through $π^0-η$ mixing and get small widths. Considering the uncertainties of the masses, for $B_{s0}$ and $B'_{s1}$, we also calculate the OZI allowed decay channels: $B_{s0}\to B\bar K$ and $B'_{s1}\to B^*\bar K…
We investigated the form factors of the $B_{c}$ meson into $P$-wave orbitally excited charmonium using the nonrelativistic QCD effective theory. Through the analytic computation, the next-to-leading order relativistic corrections to the form factors were obtained, and the asymptotic expressions were studied in the infinite bottom quark mass limit. Employing the general form factors, we discussed the exclusive decays of the $B_{c}$ meson into $P$-wave orbitally excited charmonium and a light meson. We found that the relativistic corrections lead to a large correction for the form factors, which…
Stimulated by recent progress made by the LHCb Collaboration in discoveries of new bottom baryons, e.g., the $Ξ_{b}(6227)^{-}$ and the $Σ_{b}(6097)^{\pm}$, we re-examine the orbitally excited spectrum of the charmed and bottom baryons using Regge approach in the heavy quark-diquark picture. The results indicate that the spin-averaged mass spectrum of the orbitally-excited charmed and bottom baryons can be described by a linear Regge relation, which is derived from the rotating QCD string model. By giving further mass-splitting analysis of spin-dependent interactions, we explain the baryons $Ξ_…
Exclusive semileptonic decays of B mesons to orbitally excited D mesons are considered beyond the infinitely heavy quark limit in the framework of the relativistic quark model based on the quasipotential approach. This model agrees with the structure of heavy quark mass corrections predicted by the heavy quark effective theory and allows the determination of corresponding leading and subleading Isgur-Wise functions. It is found that both relativistic and 1/m_Q contributions significantly influence the decay rates. Thus, relativistic transformations of the meson wave functions (Wigner rotation …
We present a model-independent analysis of the mass spectrum of nonstrange l=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a basis of effective operators that spans the nine observables (seven masses and two mixing angles). Comparison to the data provides support for the validity of the 1/N_c expansion, but also reveals that only a few nontrivial operators are strongly preferred. We show that our results have a consistent interpretation in a constituent quark model with pseudoscalar meson exchange interactions.
We consider a new approach towards constructing approximate holographic duals of QCD from experimental hadron properties. This framework allows us to derive a gravity dual which reproduces the empirically found linear square-mass trajectories of universal slope for radially and orbitally excited hadrons. Conformal symmetry breaking in the bulk is exclusively due to infrared deformations of the anti-de Sitter metric and governed by one free mass scale proportional to Lambda_QCD. The resulting background geometry exhibits dual signatures of confinement and provides the first examples of holograp…
The Belle Collaboration has recently reported a study of the decays $B \to D_{s1}(2536)^{+}\bar{D}^{(\ast)}$ and has given also estimates of relevant ratios between branching fractions of decays $B \to D^{(\ast)}D_{sJ}^{(\ast)}$ providing important information to check the structure of the $D_{s0}^{\ast}(2317)$, $D_{s1}(2460)$ and $D_{s1}(2536)$ mesons. The disagreement between experimental data and Heavy Quark Symmetry has been used as an indication that $D_{s0}^{\ast}(2317)$ and $D_{s1}(2460)$ mesons could have a more complex structure than the canonical $c\bar{s}$ one. We analyze these rati…
We review results for the mass spectrum of orbitally excited baryons obtained in the $1/N_c$ expansion. We show the dependence of various contributions to the mass operator as a function of the excitation energy.
The framework of phenomenological quark-antiquark potential (Coulomb plus linear confinement) model with the Gaussian wave function is used for detailed study of masses of the ground, orbitally and radially excited states of heavy-light $Q\overline{q}$, $\left(Q=c,q=u/d,s\right)$ mesons. We incorporate $\mathcal{O}(1/m)$ correction to the potential energy term and relativistic corrections to the kinetic energy term of the hamiltonian. The spin-hyperfine, the spin-orbit and the tensor interactions incorporating the effect of mixing are employed to obtained the pseudoscalar, the vector, radially…
Orbitally excited L=1 charm mesons are studied by QCD sum rules in the framework of heavy quark effective theory. The meson masses and the strong decay widths are obtained. This talk is based on our works of refs. 1 and 2 collaborated with Y.B. Dai, C.S. Huang, M.Q. Huang and H.Y. Jin.
The spectrum of orbitally excited $D_s$ mesons is computed in the continuum limit of quenched lattice QCD. The results are consistent with the interpretation that the narrow resonance in the $D_s π^0$ channel discovered by the BABAR Collaboration is a $J^P=0^+$ $c\bar{s}$ meson. Furthermore, within statistical errors, the $1^+-1^-$ and the $0^+-0^-$ mass splittings are equal, in agreement with the chiral multiplet structure predicted by heavy hadron chiral effective theory. On our coarsest lattice we present results from the first study of orbitally excited $D_s$ mesons with two flavors of dyn…
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 tube 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 $J^P={3\over 2}^+$ one. If $Λ_c(2765)^+$ is an orbitally excited $Σ_c$, there ought to be another $J^P={3\over 2}^+$ $Λ^+_c$ with mass $\approx 2770$ MeV. In the model, there exists no $J^P={1\over 2}…
Exclusive semileptonic B decays to orbitally and radially excited charmed mesons are investigated in the first order of the heavy quark expansion. The emerging leading and subleading Isgur-Wise functions are calculated in the framework of the relativistic quark model. It is found that both relativistic and the 1/m_Q corrections play an important role and substantially modify results. An interesting interplay between different corrections is observed.
We present numerical results for the dissociation cross sections of ground-state, orbitally- and radially-excited charmonia in collisions with light mesons. Our results are derived using the nonrelativistic quark model, so all parameters are determined by fits to the experimental meson spectrum. Examples of dissociation into both exclusive and inclusive final states are considered. The dissociation cross sections of several C=(+) charmonia may be of considerable importance for the study of heavy ion collisions, since these states are expected to be produced more copiously than the J/psi. The r…
Spectrum, radii, radial wave functions at origin, decay constants and momentum widths for radial and orbital excited $B_c$ mesons are derived within non-relativistic quark model framework through finding numerical solution of the Schrodinger equation by shooting method. Masses of orbitally excited states are derived with a more simpler method that is developed by combining the uncertainty and variational principles. Masses of $B_c$ mesons are also calculated by using Momentum widths. Besides calculations, theoretical results are compared with the experimental observations which have implicatio…
In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonic decays of the orbitally $P$-wave excited $B_{s}$ meson states $B^{**}_{s}$, including the newly found narrow $B_{s1}(5830)$ and $B^{*}_{s2}(5840)$ states, into the ($D_{s1}(2536)$, $D^{*}_{s2}(2573)$) doublet are calculated from QCD sum rules. With these universal form factors, the decay rates and branching ratios are also estimated.
We obtain the first estimates of branching ratios for the weak decays of $B_c$ meson decaying to two orbitally excited mesons namely, axial-vector meson ($A$) and tensor meson ($T$), in the final state. We calculate $B_c \to T$ transition form factors using the Isgur-Scora-Grinstein-Wise II framework and consequently predict branching ratios of $ B_c \to AT $ decays in Cabibbo-Kobayashi-Maskawa favored and suppressed modes.
Motivated by recent results on charmed baryons from CLEO and FOCUS, we reexamine the couplings of the orbitally excited charmed baryons. Due to its proximity to the [Sigma_c pi] threshold, the strong decays of the Lambda_c(2593) are sensitive to finite width effects. This distorts the shape of the invariant mass spectrum in Lambda_{c1}-> Lambda_c pi^+pi^- from a simple Breit-Wigner resonance, which has implications for the experimental extraction of the Lambda_c(2593) mass and couplings. We perform a fit to unpublished CLEO data which gives M(Lambda_c(2593)) - M(Lambda_c) = 305.6 +- 0.3 MeV an…
We study two nonets of excited vector mesons, predominantly corresponding to radially excited vector mesons with quantum numbers $n\hspace{0.08cm} ^{2S+1}L_{J}$ $=2^3S_1$ and to orbitally excited vector mesons with quantum numbers $n\hspace{0.08cm} ^{2S+1}L_{J}=1^3D_1$. We evaluate two types of decays of these mesons: into two pseudoscalar mesons and into a pseudoscalar and a ground-state vector meson. We compare the results with experimental data taken from PDG. We also make predictions for the strange-antistrange state in the $1^3D_1$ nonet denoted as $ϕ(1930)$, which has not yet been discov…
Mass spectra of excited meson states consisting of u-, d-quarks and antiquarks with I = 1 are considered. The comparison between the existing experimental data and the mass values evaluated with phenomenological formulae is carried out. Problems of identification of vector and scalar meson excited states are discussed.
Although there are some experimental hints for the higher excited $ρ$ mesons, our knowledge of their properties is much poor theoretically. Based on our recent work about excited $ρ$ mesons [Phys.Rev.D104(2021)034013], we present the mass spectra and decay properties of the higher excited $ρ$ mesons with the modified Godfrey-Isgur quark model and the $^3P_0$ strong decay model, and compare our predictions with the experimental hints, which should be helpful to search for these higher excited $ρ$ mesons.
The mass spectra of the L=1 orbitally excited heavy baryons with light quarks in both the spin-flavor symmetric and the mixed representations are studied by the $1/N_c$ expansion method in the framework of the heavy quark effective theory. The mixing effect between the baryons in the two representations is also considered. The general pattern of the spectrum is predicted which will be verified by the experiments in the near future.
We use recent experimental data on charmed mesons to constrain three coupling constants in the effective lagrangian describing the interactions of excited heavy-light mesons with light pseudoscalar mesons at order $m_Q^{-1}$. Predictions in the beauty sector are also derived.
The amplitudes for one-pion mediated transitions between heavy meson excited states are obtained in the framework of the relativistic chiral quark model. The effective coupling constants to pions and the decay widths of excited heavy mesons with l<=2 for non-radially excited, and the l=0 radially excited mesons are presented for both charmed and beauty mesons. We also discuss the allowed decays of strange excited heavy mesons by emission of a K-meson.
We comment on a possibility that a high degree of degeneracy observed in the high-lying meson (hadron) spectrum is due to Coulomb symmetry. We also shortly discuss possible principal quantum numbers n + J or n + L in highly excited states.
We discuss the decays X^* -> Xe^+e^- (``Dalitz decays'') of excited heavy mesons into their ground states and an electron-positron pair. We argue that the measurement of the invariant mass spectrum of the lepton pair gives clear indication on the quantum numbers of the excited meson and thus provides an experimental test of the quark model predictions.
Exclusive semileptonic $B$ decays into excited charmed mesons are studied with QCD sum rules in the leading order of heavy quark effective theory. Two universal Isgur-Wise functions τand ζfor semileptonic B decays into four lowest lying excited $D$ mesons ($D_1$, $D_2^*$, $D'_0$, and $D'_1$) are determined. The decay rates and branching ratios for these processes are calculated.
Recently, LHCb Collaboration announced the discovery of radial excitations of $D_s$ and $B_s$ mesons. In present work, we calculate the most promising strong and electromagnetic decay widths of radially excited $D_s(2S)$ and $B_s(2S)$ mesons within the light cone QCD sum rules method.
The hadronic decay of radially and orbitally excited charmonium above charm threshold by $^3 P_{0}$ pair creation and chromoelectric flux--tube breaking is discussed in an harmonic oscillator approximation. We find independent evidence from a study of widths for a 2S admixture in the predominantly 1D state $ψ(3770)$, and explore the possibility of metastable radially excited $2 \; ^{3}P_{0,1,2}$ states being a source of the anomalously large production of $ψ^{'}$ at the Tevatron. At least one of them is expected to be narrow as a consequence of the existence of nodes in the radial wave functio…
The first radial excitations of axial-vector mesons are considered in the framework of the extended $U(3)\times U(3)$ Nambu--Jona-Lasinio model. We calculate the mass spectrum of $a_1$, $f_1$, and also strange axial-vector mesons. For description of radially excited states we used the form factors of polynomial type of the second order in transverse quark momentum. For the ground- and the excited-state mesons consisting of light quarks we have calculated the widths of a number of strong and radiative decays. We got satisfactory agreement with experimental data for the ground states. A set of p…
