We measure the time-dependent CP asymmetry in the radiative-penguin decay B0 → KS0π-π+γ , using a sample of 471×106 Υ(4S)→BB-events recorded with the BABAR detector at the PEP-II e+e- storage ring at ...SLAC. Using events with mKππ < 1.8 GeV/c2, we measure the branching fractions of B+→K+π-π+γ and B0→K0π-π+γ, the branching fractions of the kaonic resonances decaying to K+π-π+, as well as the overall branching fractions of the B+→ρ0K+γ, B+→K*0π+γ and S-wave B+→(Kπ)0*0π+γ components. For events from the ρ mass band, we measure the CP-violating parameters SKS0π+π-γ=0.14±0.25±0.03 and CKS0π+π-γ=-0.39±0.20-0.02+0.03, where the first uncertainties are statistical and the second are systematic. We extract from this measurement the time-dependent CP asymmetry related to the CP eigenstate ρ0KS0 and obtain SKS0ργ=-0.18±0.32-0.05+0.06, which provides information on the photon polarization in the underlying b→sγ transition.
We study the lepton forward-backward asymmetry AFB and the longitudinal K* polarization FL, as well as an observable P2 derived from them, in the rare decays B→K*ℓ+ℓ-, where + is either e+e- or μ+μ-, ...using the full sample of 471 million BB-events collected at the (4S) resonance with the BABAR, detector at the PEP-II e+e- collider. We separately fit and report results for the K*0(892)+ and K*+(892)+ final states, as well as their combination K*ℓ+ℓ-, in five disjoint dilepton mass-squared bins. An angular analysis of B+→K*ℓ+ℓ- decays is presented here for the first time.
We describe in detail a previously published measurement of C P violation in B 0 - ¯ B 0 oscillations, based on an integrated luminosity of 425.7 fb − 1 collected by the BABAR experiment at the ...PEPII collider. We apply a novel technique to a sample of about 6 million ¯ B 0 → D * + ℓ − ¯ ν ℓ decays selected with partial reconstruction of the D * + meson. The charged lepton identifies the flavor of one B meson at its decay time, the flavor of the other B is determined by kaon tagging. We determine a C P violating asymmetry A C P = ( N ( B 0 B 0 ) − N ( ¯ B 0 ¯ B 0 ) ) / ( N ( B 0 B 0 ) + N ( ¯ B 0 ¯ B 0 ) ) = ( 0.06 ± 0.1 7 + 0.38 − 0.32 ) % corresponding to Δ C P = 1 − | q / p | = ( 0.29 ± 0.8 4 + 1.88 − 1.61 ) × 1 0 − 3 . This measurement is consistent and competitive with those obtained at the B factories with dilepton events.
We report on measurements of the decays of $\bar{B}$ mesons into the semileptonic final states $\bar{B}$→D(*)π+π-l-$\bar{v}$, where D(*) represents a D or D* meson and l- is an electron or a muon. ...These measurements are based on 471×106 B$\bar{B}$ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R$(*)\atop{π+π-}$ = B($\bar{B}$→D(*)π+π-l-$\bar{v}$)/B($\bar{B}$→D(*)l-$\bar{v}$) using events in which the second B meson is fully reconstructed. We find Rπ+π-=0.067 ± 0.010 ± 0.008 and R$*\atop{π+π-}$ = 0.019 ± 0.005 ± 0.004, where the first uncertainty is statistical and the second is systematic. Lastly, based on these results and assuming isospin invariance, we estimate that $\bar{B}$→D(*)ππl-$\bar{v}$ decays, where π denotes either a π± and π0 meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.
Initial state radiation (ISR) events produced in
e
+
e
− collisions at the ϒ(4S) energy region can provide access to
e
+
e
− annihilations at lower C. M. energies. At B-factory experiments the data ...rate is substantial for physics at all energies below the ϒ(4S). This paper describes the tagging of the ISR events, and identifies several physics topics that can be studied with the ISR data.
The mass m(eta(c)) and total width Gamma(eta(c))(tot) of the eta(c) meson have been measured in two-photon interactions at the SLAC e(+)e(-) asymmetric B Factory with the BABAR detector. With a ...sample of approximately 2500 reconstructed eta(c)-->K(0)(S)K+/-pi(-/+) decays in 88 fb(-1) of data, the results are m(eta(c))=2982.5+/-1.1(stat)+/-0.9(syst) MeV/c(2) and Gamma(eta(c))(tot)=34.3+/-2.3(stat)+/-0.9(syst) MeV/c(2). Using the same decay mode, a second resonance with 112+/-24 events is observed with a mass of 3630.8+/-3.4(stat)+/-1.0(syst) MeV/c(2) and width of 17.0+/-8.3(stat)+/-2.5(syst) MeV/c(2). This observation is consistent with expectations for the eta(c)(2S) state.
We present measurements of the B → η ′ K branching fractions; for B + → η ′ K + we measure also the time-integrated charge asymmetry A ch , and for B 0 → η ′ K 0 S the time-dependent C P -violation ...parameters S and C . The data sample corresponds to 232 × 10 6 B ¯¯¯ B pairs produced by e + e − annihilation at the Υ ( 4 S ) . The results are B ( B → η ′ K + ) = ( 68.9 ± 2.0 ± 3.2 ) × 10 − 6 , B ( B 0 → η ′ K 0 ) = ( 67.4 ± 3.3 ± 3.2 ) × 10 − 6 , A ch = 0.033 ± 0.028 ± 0.005 , S = 0.30 ± 0.14 ± 0.02 , and C = − 0.21 ± 0.10 ± 0.02 , where the first error quoted is statistical and the second is systematic.
The results of amplitude analyses of the Mark III data on the K{sub s}{sup 0}K{sub s}{sup 0}, K{sup +}K{sup -} and {pi}{sup +}{pi}{sup -} systems produced in J/{psi} radiative decay are shown for the ...mass range 1-2 GeV. The intensity distributions for the amplitudes having J{sup PC} values 0{sup ++} and 2{sup ++} are presented and discussed. The observed strong production of the f{sub 0}(1700) in J/{psi} radiative decay suggests that this state may consist primarily of the lightest scalar glueball state. No significant production of spin 2 is observed in the 1.7 GeV mass region.
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