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BABAR Collaboration(del Amo Sanchez, P. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Observation of the rare decay B-0 -> K-S(0) K-+/-pi(-/+). Phys. Rev. D, 82(3), 031101–8pp.
Abstract: We report an analysis of charmless hadronic decays of neutral B mesons to the final state (KSK +/-)-K-0 pi(-/+) (sic), using a data sample of (465 +/- 5) x 10(6) B (B) over bar events collected with the BABAR detector at the Gamma(4S) resonance. We observe an excess of signal events with a significance of 5.2 standard deviations including systematic uncertainties and measure the branching fraction to be B(B-0 -> (KSK +/-)-K-0 pi(-/+) (sic) (3.2 +/- 0.5 +/- 0.3) x 10(-6), where the uncertainties are statistical and systematic, respectively.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., & Oyanguren, A. (2011). Search for Production of Invisible Final States in Single-Photon Decays of Gamma(1S). Phys. Rev. Lett., 107(2), 021804–7pp.
Abstract: We search for single-photon decays of the Gamma(1S) resonance, Gamma -> gamma + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A(0), or a pair of dark matter particles, chi(chi) over bar. Both A(0) and chi are assumed to have zero spin. We tag Gamma(1S) decays with a dipion transition Gamma(1S) -> pi(+)pi(-)Y(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A0) <= 9.2 GeV and m(chi) <= 4.5 GeV in the sample of 98 x 10(6) Gamma(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2011). Observation of eta(c) (1S) and eta(c) (2S) decays to K(+)K(-) pi(+) pi(-) pi(0) in two-photon interactions. Phys. Rev. D, 84(1), 012004–9pp.
Abstract: We study the processes gamma gamma -> K(S)(0) K(-+) pi(-+) and gamma gamma -> K(+)K(-) pi(+)pi(-)pi(0) using a data sample of 519: 2fb(-1) recorded by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at center-of-mass energies near the Y(nS) (n = 2, 3, 4) resonances. We observe the eta(c) (1S), chi(c0) (1P) and eta(c) (2S) resonances produced in two-photon interactions and decaying to K(+)K(-) pi(+)pi(-)pi(0), with significances of 18.1, 5.4 and 5.3 standard deviations (including systematic errors), respectively, and report 4.0 sigma evidence of the X(c2)(1P) decay to this final state. We measure the eta(c)(2S) mass and width in K(S)(0) K(+-) pi(+-) decays, and obtain the values m(eta(c)(2S)) = 3638: 5 +/- 1.5 +/- 0.8 MeV/c(2) and Gamma(eta(c)(2S)) = 13.4 +/- 4: 6 +/- 3.2 MeV, where the first uncertainty is statistical and the second is systematic. We measure the two-photon width times branching fraction for the reported resonance signals, and search for the X(c2) (2P) resonance, but no significant signal is observed.
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BABAR Collaboration(del Amo Sanchez, P. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). B-meson decays to eta ' rho, eta ' f(0), and eta ' K*. Phys. Rev. D, 82(1), 011502–8pp.
Abstract: We present measurements of B-meson decays to the final states eta'rho, eta'f(0), and eta'K*, where K* stands for a vector, scalar, or tensor strange meson. We observe a significant signal or evidence for eta'rho(+) and all the eta'K* channels. We also measure, where applicable, the charge asymmetries, finding results consistent with no direct CP violation in all cases. The measurements are performed on a data sample consisting of 467 X 10(6) B (B) over bar pairs, collected with the BABAR detector at the PEP-II e(+)e(-) collider at the SLAC National Accelerator Laboratory. Our results favor the theoretical predictions from perturbative QCD and QCD factorization and we observe an enhancement of the tensor K-2*(1430) with respect to the vector K*(892) component.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Evidence for the decay X(3872) -> J/psi omega. Phys. Rev. D, 82(1), 011101–8pp.
Abstract: We present a study of the decays B-0,B-+ -> J/psi pi(+)pi(-)pi K-0(0,+), using 467 x 106 B (B) over bar pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) -> J/psi omega, with product branching fractions B(B+ -> X(3872K(+)) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.2(stat) +/- 0.1(syst)] x 10(-5), and B(B-0 -> X(3872)K-0) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.3(stat) +/- 0.1(syst)] x 10(-5). A detailed study of the pi(+) pi(-) pi(0) mass distribution from X(3872) decay favors a negative-parity assignment.
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