A chiral Lagrangian approach to radiative vector meson decays

The radiative decays of vector mesons are considered from an effective Lagrangian point of view. It is pointed out that the crucial question of flavour symmetry breaking in these decays has an almost unique solution in this approach; this solution involves non orthogonal mixing of the ω and the π. The decay rates are calculated and compared with experiment.     

Observation of chicJ radiative decays to light vector mesons

Using a total of 2.74 x 10(7) decays of the psi(2S) collected with the CLEO-c detector, we present a study of chi(cJ)-->gammaV, where V=rho(0), omega, phi. The transitions chi(c1)-->gammarho(0 and chi(c1)-->gammaomega are observed with B(chi(c1)-->gammarho(0))=(2.43+/-0.19+/-0.22) x 10(-4) and B(chi(c1)-->gammaomega)=(8.3+/-1.5+/-1.2) x 10(-5). In the chi(c1)-->gammarho(0) transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other chi(cJ) states to light vector mesons are presented.     

Hadronic three-body decays of light vector mesons

The decays of light vector mesons into three pseudoscalar mesons are calculated to leading order in the recently proposed counting scheme that is based on the hadrogenesis conjecture. Fully differential as well as integrated decay widths are presented. Since the required parameters have been fixed by other processes, the considered three-body decays are predictions of the presented approach. The decay width of the omega meson into three pions agrees very well with the experiment. The partial decay widths of the K^* into its three K channels are predicted.     

Strong decays of radially excited vector mesons

Motivated by the recent discovery at Orsay of ?′ (1680), we study the strong interaction decays of radially excited vector mesons within the framework of the³ P ₀ quark pair creation model. We stress the relative importance of phase space, algebraic spinflavor couplings, and spatial overlaps. Quite a few features of the data can be will understood by the presence of a node in the spatial wave function, but the detailed structure of the modes ρ′→4π remains a serious challenge.     

On some rare weak decays of vector mesons

Some semileptonic weak decays of vector mesons are considered within the most popular quark models. Unfortunately, the predicted branching ratios are too small to make a study of these decays realistic at meson factories under construction.     

Symmetry breaking schemes and radiative decays of vector mesons

We have studied a hierarchy of SU(3) breaking schemes for the radiative decays of the vector mesons. In all of the four models we examine in detail, we find it hard to reconcile the newly measured radiative widths of ? → πγ, $\text{K}{}^{01}\text{→ K}{}^0\text{γ}$, φ → πγ, and φ → ηγ with the older measurements and upper bounds on other radiative rates. In particular we have difficulty in understanding the narrow radiative width of ?. A possible extension to an SU(4) symmetry breaking scheme is also suggested.     

Radiative decays of heavy vector mesons into paraquarkonia

The width for decays of the type 1^?→γ + 0^? is evaluated using the two gluon mechanism of QCD. In particular we compute Γ(Ψ → γ + η′), Γ(Ψ → γ + η) and Γ(? → γ + η_c). The first two are found to be in reasonable agreement with the experimental results, while the latter leads to a branching ratio of 2 × 10^?5.     

Understanding the radiative decays of vector charmonia to light pseudoscalar mesons

We show that the newly measured branching ratios of vector charmonia (J/ψ$J/\psi$, ψ^′${\psi }^{\prime }$ and ψ(3770)$\psi (3770)$) into γP, where P   stands for light pseudoscalar mesons π⁰${\pi }^0$, η  , and η^′${\eta }^{\prime }$, can be well understood in the framework of vector meson dominance (VMD) in association with the ηc–η(η^′)${\eta }_c\text{–}\eta ({\eta }^{\prime })$ mixings due to the axial gluonic anomaly. These two mechanisms behave differently in J/ψ$J/\psi$ and ψ^′→γP${\psi }^{\prime }\to \gamma P$. A coherent understanding of the branching ratio patterns observed in J/ψ(ψ^′)→γP$J/\psi ({\psi }^{\prime })\to \gamma P$ can be achieved by self-consistently including those transition mechanisms at hadronic level. The branching ratios for ψ(3770)→γP$\psi (3770)\to \gamma P$ are predicted to be rather small.     

Weak decays of heavy vector mesons toponium and open top

We point out that for sufficiently heavy top quark masses, i.e.,m _t ?20 GeV, weak interactions govern the decays ofboth the corresponding pseudoscalar and vector mesons,T andT ^* . Furthermore they significantly modify toponium decays. We discuss in detail the implications forT _b ^* decays and describe how especially its leptonic decays provide such spectacular signatures that they could serve to detect top production in hadron-hadron collisions. We also draw a scenario for toponium decays.     

Quark structure and weak decays of heavy mesons

We construct a cellular space which has as a continuous limit the Euclidean spaceR ^N . We consider quantum mechanics on this cellular space and we examine in particular an harmonic oscillator and a free particle on the cellularR ¹,R ² respectively. In both cases we find that the energy spectrum is bounded from above.Partially supported by CEC Science project No SC1-CT91-0729     

Inclusive production of neutral vector mesons in hadronic Z decays

A data sample of about 3.0 million hadronicZ decays collected by the ALEPH experiment at LEP in the years 1991 through 1994 is used to make an inclusive selection of B hadron events. In this event sample 4227±140±252B* mesons in the decayB*→Bγ and 1944±108±161B** _u,d mesons decaying into a B meson and a charged pion are reconstructed. Here and in the followingB** _u,d denotes the eightL=1(bū) and (bd) states and their charge conjugate. For the well establishedB* meson the following quantities are obtained:ΔM=M _B*−M_B=(45.30±0.35±0.87) MeV/c² andN _B*/(N _B+N _B*)=(77.1±2.6±7.0)%. The angular distribution of the photons in theB* rest frame is used to measure the relative contribution of longitudinalB* polarization states to beσ _L/(σ _L+σ _T)=(33±6±5)%.     

Lepton flavor violating decays of vector mesons in the MRSSM

In this study, we analyze the rare decays of the neutral vector mesons J/ψ and Υ(nS) in the scenario of the minimal R-symmetric supersymmetric standard model using the effective Lagrangian method. The predicted branching ratios are dominated by the mass insertion parameters δ^ij, i.e., the off-diagonal inputs, and the contributions of different parts are comparable. Taking into account the experimental constraints on the mass insertion parameters, the predicted branching ratios for the...