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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2011). Search for Hadronic Decays of a Light Higgs Boson in the Radiative Decay Gamma -> gamma A(0). Phys. Rev. Lett., 107(22), 221803–7pp.
Abstract: We search for hadronic decays of a light Higgs boson (A(0)) produced in radiative decays of an Gamma(2S) or Gamma(3S) meson, Gamma -> gamma A(0). The data have been recorded by the BABAR experiment at the Gamma(3S) and Gamma(2S) center-of-mass energies and include (121.3 +/- 1.2) x 10(6) Gamma(3S) and (98.3 +/- 0.9) x 10(6) Gamma(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Gamma(nS) -> gamma A(0))B(A(0) -> hadrons) (n = 2 or 3) that range from 1 x 10(-6) for an A(0) mass of 0: 3 GeV/c(2) to 8 x 10(-5) at 7 GeV/c(2).
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Albertus, C., Hernandez, E., & Nieves, J. (2011). Exclusive c -> s, d semileptonic decays of ground-state spin-1/2 doubly charmed baryons. Phys. Lett. B, 704(5), 499–509.
Abstract: We evaluate exclusive semileptonic decays of ground-state spin-1/2 doubly heavy charmed baryons driven by a c -> s, d transition at the quark level. Our results for the form factors are consistent with heavy quark spin symmetry constraints which are valid in the limit of an infinitely massive charm quark and near zero recoil. Only a few exclusive semileptonic decay channels have been theoretically analyzed before. For those cases we find that our results are in a reasonable agreement with previous calculations.
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2011). Search for a Heavy Toplike Quark in p p-bar Collisions at sqrt(s)=1.96 TeV. Phys. Rev. Lett., 107(26), 261801–8pp.
Abstract: We present the results of a search for pair production of a heavy toplike (t') quark decaying to Wq final states using data corresponding to an integrated luminosity of 5.6 fb(-1) collected by the CDF II detector in p (p) over bar collisions at root s = 1.96 TeV. We perform parallel searches for t' -> Wb and t' -> Wq (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t' quark mass, we set upper limits on the t'(t) over bar' production cross section and exclude a standard model fourth-generation t' quark decaying to Wb (Wq) with mass below 358 (340) GeV/c(2) at 95% C. L.
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Doring, M., Meissner, U. G., Oset, E., & Rusetsky, A. (2011). Unitarized Chiral Perturbation Theory in a finite volume: Scalar meson sector. Eur. Phys. J. A, 47(11), 139–15pp.
Abstract: We develop a scheme for the extraction of the properties of the scalar mesons f(0)(600), f(0)(980), and a(0)(980) from lattice QCD data. This scheme is based on a two-channel chiral unitary approach with fully relativistic propagators in a finite volume. In order to discuss the feasibility of finding the mass and width of the scalar resonances, we analyze synthetic lattice data with a fixed error assigned, and show that the framework can be indeed used for an accurate determination of resonance pole positions in the multichannel scattering.
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ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Escobar, C., et al. (2011). Measurement of the Z -> tau tau cross section with the ATLAS detector. Phys. Rev. D, 84(11), 112006–29pp.
Abstract: The Z -> tau tau cross section is measured with the ATLAS experiment at the LHC in four different final states determined by the decay modes of the tau leptons: muon-hadron, electron-hadron, electron-muon, and muon-muon. The analysis is based on a data sample corresponding to an integrated luminosity of 36 pb(-1), at a proton-proton center-of-mass energy of root s = 7 TeV. Cross sections are measured separately for each final state in fiducial regions of high detector acceptance, as well as in the full phase space, over the mass region 66-116 GeV. The individual cross sections are combined and the product of the total Z production cross section and Z -> tau tau branching fraction is measured to be 0.97 +/- 0.07(stat) +/- 0.06(syst) +/- 0: 03(lumi) nb, in agreement with next-to-next-to-leading order calculations.
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