Measurements of branching fractions for B^+ → p^+γ, B^0 → p^0γ, and B^0 → ωγ

We present branching fraction measurements for the radiative decays B^+ → ρ^+ γ, B^0 → ρ^0 γ, and B^0 → ωγ. The analysis is based on a data sample of 465 × 10^6 B[overline B] events collected with the BABAR detector at the PEP-II asymmetric-energy B Factory located at the Stanford Linear Accelerator Center. We find [script B](B^+ → ρ^+ γ) = (1.20_(-0.37)^(+0.42) ± 0.20) × 10^(-6), [script B](B^0 → ρ^0γ) = (0.97_(-0.22)^(+0.24) ± 0.06) × 10^(-6), and a 90% C.L. upper limit [script B](B^0 → ωγ) < 0.9 × 10^(-6), where the first error is statistical and the second is systematic. We also measure the isospin-violating quantity Γ(B^+ → ρ^+ γ)/2Γ(B^0 → ρ^0γ)-1 = -0.43_(-0.22)^(+0.25)±0.10

Measurement of the γγ*→π0 transition form factor

We study the reaction e + e − → e + e − π 0 in the single tag mode and measure the differential cross section d σ / d Q 2 and the γ γ ∗ → π 0 transition form factor in the momentum transfer range from 4 to 40     GeV 2 . At Q 2 > 10     GeV 2 the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442     fb − 1 of integrated luminosity collected at PEP-II with the BABAR detector at e + e − center-of-mass energies near 10.6 GeV

Unsaturated σ-hydrocarbyl transition-metal complexes. Part 2. Synthesis and reactions of vinylplatinum complexes and a comparison with analogous fluorovinyl and alkynyl complexes

Alkenyl (CHCH2 or CFCF2) or alkynyl (CCPh) derivatives of trimethyltin are shown to be superior to lithium or magnesium reagents for the synthesis of corresponding mono-organoplatinum(II) species by metathesis (L = SnMe3R +cis-[PtCl2L2]→trans-[PtRClL2]+ SnMe3Cl tertiary phosphine). The reactivity order for SnMe3R is R = CCPh > CFCF2 > CHCH2. This order is also found for oxidative addition of SnMe3R to Pt0 to give cis-[PtRL2(SnMe3)]. When the latter complex (R = CHCH2) reacts with X2 or MeX further oxidative addition occurs exclusively at the platinum centre. Aromatic isonitriles (R′NC)co-ordinate to the platinum and give insertion products trans-[Pt{C(CHCH2)= NR′}ClL2] on heating or carbene complexes with NBunH2. The alkynyl trans-[Pt(CCPh)ClL2] also forms 1 :1 adducts with R′NC and carbene complexes therefrom, but no insertion products. Spectroscopic data for the new complexes are presented

Exclusive production of D_{s}^{+}D_{s}^{-}, D_{s}^{*+}D_{s}^{-}, and D_{s}^{*+}D_{s}^{*-} via e^{+}e^{-} annihilation with initial-state radiation

We perform a study of exclusive production of Ds+Ds-, Ds*+Ds-, and Ds*+Ds*- final states in initial-state-radiation events from e+e- annihilations at a center-of-mass energy near 10.58 GeV, to search for charmonium 1-- states. The data sample corresponds to an integrated luminosity of 525  fb-1 and was recorded by the BABAR experiment at the PEP-II storage ring. The Ds+Ds-, Ds*+Ds-, and Ds*+Ds*- mass spectra show evidence of the known ψ resonances. Limits are extracted for the branching ratios of the decays X(4260)→Ds(*)+Ds(*)-