Results from a partial-wave analysis of the decay {ital J}/{psi}{r arrow}{gamma}{ital K}{sub {ital S}}{sup 0}{ital K{plus minus}}{pi}{sup {minus plus}} in the {ital K}{sub {ital S}}{sup 0}{ital ...K}{sup {plus minus}}{pi}{sup {minus plus}} invariant-mass range 1.35--1.6 GeV/{ital c}{sup 2} are presented. Within the isobar model, the data in this mass range are best described by a mixture of 0{sup {minus}+} and 1{sup ++} amplitudes, corresponding to the {ital K}{sup *}{ital {bar K}}+c.c ({ital P} wave), {ital K}{sup *}{ital {bar K}}+c.c ({ital S} wave), and {ital a}{sub 0}(980) {pi} ({ital S} wave) channels. These results show that {eta}(1430) is not a {ital J}{sup {ital P}{ital C}}=0{sup {minus}+} {ital a}{sub 0}(980){pi} resonance, but a mixture of overlapping states.
We determine the resonant substructure of {ital D}{sup 0}{r arrow}{ital K}{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}} decays using a five-dimensional maximum-likelihood technique to extract ...the relative fractions and phases of the amplitudes contributing to this final state. We find that two-body decay modes account for at least 76% of all decays. We obtain branching ratios for several decay modes including {ital B}({ital D}{sup 0}{r arrow}{ital K}{sup {minus}}{ital a}{sub 1}{sup +}) =(9.0{plus minus}0.9{plus minus}1.7)%, {ital B}({ital D}{sup 0}{r arrow}{ital {bar K}} {sup *0}{rho}{sup 0})=(1.9{plus minus}0.3{plus minus}0.7)%, and {ital B}({ital D}{sup 0}{r arrow}{ital K}{sub 1}(1270){sup {minus}}{pi}{sup +}) =(1.8{plus minus}0.5 {plus minus}0.8)%. For the decay mode {ital D}{sup 0}{r arrow}{ital {bar K}} {sup *0}{rho}{sup 0}, the {ital {bar K}} {sup *0} and {rho}{sup 0} are found to be polarized with their spins oriented in the direction of their motion as seen from the {ital D}{sup 0} frame.
We report a study of the hadronic branching fractions of the {ital D}{sub {ital s}}{sup +} meson, which is used to extract an upper limit on the absolute branching fraction for {ital D}{sub {ital ...s}}{sup +}{r arrow}{phi}{pi}{sup +}. A search is made for fully reconstructed events from the reaction {ital e}{sup +}{ital e}{sup {minus}}{r arrow}D{sub s}{sup *{plus minus}}D{sub s}{sup {minus plus}}, {ital D}{sub {ital s}}{sup *{plus minus}}{r arrow}{gamma}D{sub s}{sup {plus minus}}, using seven exclusive {ital D}{sub {ital s}}{sup +} decay modes. The data sample of 6.30{plus minus}0.46 ppB{sup {minus}1} was collected at {radical}{ital {bar s}}=4.14 GeV with the Mark III detector at the SLAC {ital e}{sup +}{ital e{minus}} storage ring SPEAR. No candidate events are observed. The measured relative {ital D}{sub {ital s}}{sup +} branching fractions and {sigma}{ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}) are used to establish the limit {ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}){lt}4.1% at 90% confidence level.
We present a study of the decay sequence {ital J}/{psi}{r arrow}{gamma}{ital X}, {ital X}{r arrow}{gamma}{rho}{sup 0}, {rho}{sup 0}{r arrow}{pi}{sup +}{pi}{sup {minus}}, based on 5.8{times}10{sup 6} ...produced {ital J}/{psi} collected by the Mark III detector at the SLAC storage ring SPEAR. In the {gamma}{rho}{sup 0} mass spectrum, we find two peaks with masses and widths consistent with the axial-vector mesons {ital f}{sub 1}(1285) and {ital f}{sub 1}(1420) that have recently been observed in two-photon collisions. Fits to the angular distributions confirm that the first peak is an axial-vector state, but are unable to distinguish between the {ital f}{sub 1}(1420) or the pseudoscalar {eta}(1430) for the high-mass peak. Product branching fractions for both objects are presented.
We determine the resonant substructure of {ital D}{r arrow}{ital {bar K}}{pi}{pi}{pi} decays, extracting the relative fractions and phases of the amplitudes contributing to the {ital K}{sup ...{minus}}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}, {ital {bar K}} {sup 0}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}, {ital K}{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup 0}, and {ital {bar K}} {sup 0}{pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} final states. We find that two-body decay modes account for at least 75% of these decays. We obtain branching ratios for {ital D}{r arrow}{ital {bar K}a}{sub 1}(1260), {ital D}{r arrow}{ital {bar K}} {sup *}{rho}, {ital D}{r arrow}{ital {bar K}}{sub 1}(1270){pi}, {ital D}{r arrow}{ital {bar K}}{sub 1}(1400){pi}, and {ital D}{sup 0}{r arrow}{ital {bar K}} {sup 0}{omega} decay modes, as well as for several three- and four-body decay modes. In the case of {ital D}{r arrow}{ital {bar K}a}{sub 1}(1260) and {ital D}{r arrow}{ital {bar K}} {sup *}{rho}, we obtain the branching ratios for all three possible isospin combinations, enabling us to extract the isospin-1/2 and -3/2 amplitudes, and their relative phases. We find that the isospin-3/2 amplitudes are suppressed relative to the isospin-1/2 amplitudes. This implies that the widths of the {ital D}{sup +} modes are suppressed relative to those of the {ital D}{sup 0}, confirming that an understanding of the lifetime difference of the {ital D}{sup 0} and {ital D}{sup +} depends on an understanding of two-body hadronic decays. For the {ital D}{r arrow}{ital {bar K}} {sup *}{rho} decay modes, we obtain detailed information on the polarization of the {ital {bar K}} {sup *} and {rho}. This enables us to place constraints on the form factors for {ital D}{r arrow}{ital {bar K}} {sup *} and {ital D}{r arrow}{rho} transitions.
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