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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BABAR Collaboration(del Amo Sanchez, P. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays. Phys. Rev. D, 81(11), 111103–8pp.
Abstract: We search for CP violation in a sample of 4.7 x 10(4) Cabibbo suppressed D-0 -> K+K-pi(+)pi(-) decays. We use 470 fb(-1) of data recorded by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage rings running at center-of-mass energies near 10.6 GeV. CP violation is searched for in the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D-0 and (D) over bar (0) decays. The measured CP violation parameter is A(T) = (1.0 +/- 5.1(stat) +/- 4.4(syst)) x 10(-3).
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BABAR Collaboration(Lees, J. P. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Limits on tau lepton-flavor violating decays into three charged leptons. Phys. Rev. D, 81(11), 111101–8pp.
Abstract: A search for the neutrinoless, lepton-flavor violating decay of the tau lepton into three charged leptons has been performed using an integrated luminosity of 468 fb(-1) collected with the BABAR detector at the PEP-II collider. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1.8-3.3) x 10(-8) at 90% confidence level.
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DELPHI Collaboration(Abdallah, J. et al), Costa, M. J., Ferrer, A., Fuster, J., Garcia, C., Oyanguren, A., et al. (2010). Study of the dependence of direct soft photon production on the jet characteristics in hadronic Z (0) decays. Eur. Phys. J. C, 67(3-4), 343–366.
Abstract: An analysis of the direct soft photon production rate as a function of the parent jet characteristics is presented, based on hadronic events collected by the DELPHI experiment at LEP1. The dependences of the photon rates on the jet kinematic characteristics (momentum, mass, etc.) and on the jet charged, neutral and total hadron multiplicities are reported. Up to a scale factor of about four, which characterizes the overall value of the soft photon excess, a similarity of the observed soft photon behavior to that of the inner hadronic bremsstrahlung predictions is found for the momentum, mass, and jet charged multiplicity dependences. However for the dependence of the soft photon rate on the jet neutral and total hadron multiplicities a prominent difference is found for the observed soft photon signal as compared to the expected bremsstrahlung from final state hadrons. The observed linear increase of the soft photon production rate with the jet total hadron multiplicity and its strong dependence on the jet neutral multiplicity suggest that the rate is proportional to the number of quark pairs produced in the fragmentation process, with the neutral pairs being more effectively radiating than the charged ones.
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BABAR Collaboration(Aubert, B. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Observation of the chi(c2)(2P) meson in the reaction gamma gamma -> D(D)over-bar at BABAR. Phys. Rev. D, 81(9), 092003–16pp.
Abstract: A search for the Z(3930) resonance in gamma gamma production of the D (D) over bar system has been performed using a data sample corresponding to an integrated luminosity of 384 fb(-1) recorded by the BABAR experiment at the PEP-II asymmetric-energy electron-positron collider. The D (D) over bar invariant mass distribution shows clear evidence of the Z(3930) state with a significance of 5.8 sigma. We determine mass and width values of (3926.7 +/- 2.7 +/- 1.1) MeV/c(2) and (21.3 +/- 6.8 +/- 3.6) MeV, respectively. A decay angular analysis provides evidence that the Z(3930) is a tensor state with positive parity and C parity (J(PC) = 2(++)); therefore we identify the Z(3930) state as the chi(c2)(2P) meson. The value of the partial width Gamma(gamma gamma) x B(Z(3930) -> D (D) over bar) is found to be (0.24 +/- 0.05 +/- 0.04) keV.
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