Study of high momentum eta' production in B --> eta'Xs

We measure the branching fraction for the charmless semi-inclusive process B --> eta'Xs, where the eta' meson has a momentum in the range 2.0 to 2.7 GeV/c in the upsilon4S center-of-mass frame and Xs represents a system comprising a kaon and zero to four pions. We find B(B --> eta'Xs) = [3.9 +/- 0.8(stat) +/- 0.5(syst) +/- 0.8(model)] x 10(-4). We also obtain the Xs mass spectrum and find that it fits models predicting high masses.     

Limits on the decay-rate difference of neutral B mesons and on CP, T, and CPT violation in B(0-0)B oscillations

Using events in which one of two neutral B mesons from the decay of an Upsilon(4S) meson is fully reconstructed, we determine parameters governing decay (DeltaGamma(d)/Gamma(d)), CP, and T violation (|q/p|), and CP and CPT violation (Re z,Im z). The results, obtained from an analysis of 88 x 10(6) Upsilon(4S) decays recorded by BABAR, are sgn(Re lambda(CP))DeltaGamma(d)/Gamma(d)=-0.008+/-0.037(stat)+/-0.018(syst)[-0.084,0.068],|q/p|=1.029+/-0.013(stat)+/-0.011(syst)[1.001,1.057],(Re lambda(CP)/|lambda(CP)|) Re z=0.014+/-0.035(stat)+/-0.034(syst)[-0.072,0.101],Im z=0.038+/-0.029(stat)+/-0.025(syst)[-0.028,0.104]. The values inside the square brackets indicate the 90% confidence-level intervals. These results are consistent with standard model expectations.     

Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.     

Search for the radiative decays B-->rhogamma and B0-->omegagamma

A search of the exclusive radiative decays B-->rho(770)gamma and B0-->omega(782)gamma is performed on a sample of about 84x10(6) BBmacr; events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- storage ring. No significant signal is seen in any of the channels. We set upper limits on the branching fractions B of B(B0-->rho(0)gamma)<1.2 x 10(-6), B(B+-->rho+gamma)<2.1 x 10(-6), and B(B0-->omegagamma)<1.0 x 10(-6) at 90% confidence level (C.L.). Using the assumption that Gamma(B-->rhogamma)=Gamma(B+-->rho(+)gamma)=2 x Gamma(B0-->rho(0)gamma), we find the combined limit B(B-->rhogamma)<1.9 x 10(-6), corresponding to B(B-->rhogamma)/B(B-->K*gamma)<0.047 at 90% C.L.     

Measurement of the inclusive charmless semileptonic branching ratio of B mesons and determination of |V ub|

We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89 x 10(6) (-)BB events recorded with the BABAR detector at the Upsilon(4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the mass distribution of the hadronic system accompanying the lepton and is used to determine the ratio of branching fractions B((-)B-->X(u)lnu;)/B((-)B-->Xlnu;)=[2.06+/-0.25(stat)+/-0.23(syst)+/-0.36(theo)]x10(-2). Using the measured branching fraction for inclusive semileptonic B decays, we find B((-)B-->X(u)lnu;)=[2.24+/-0.27(stat)+/-0.26(syst)+/-0.39(theo)]x10(-3) and derive the Cabibbo-Kobayashi-Maskawa matrix element |V(ub)|=[4.62+/-0.28(stat)+/-0.27(syst)+/-0.48(theo)]x10(-3).     

Improved Measurement of the Cabibbo-Kobayashi-Maskawa angle alpha using B0(B) --> rho+rho- decays

We present results from an analysis of B(0)B(0)--> rho(+)rho(-) using 232 x 10(6) Gamma (4S) --> BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We measure the longitudinal polarization fraction f(L) = 0.978 +/- 0.014(stat) + 0.021 / -0.029(syst) and the CP-violating parameters S(L)= -0.33 +/- 0.24(stat) + 0.08 / -0.14(syst) and C(L)= -0.03 +/- 0.18(stat) +/- 0.09(syst). Using an isospin analysis of B --> rhorho decays, we determine the unitarity triangle parameter alpha. The solution compatible with the standard model is alpha = (100 +/- 13) degrees.     

New approach to the measurement of the nonlinear refractive index of short (<25 m) lengths of silica and erbium-doped fibers

The nonlinear refractive index n2 of silica fiber (24 m) and erbium-doped fiber (10 m) is measured to within an accuracy of 5% by use of time-delayed photorefractive beam coupling of intense 53-ps, 1.064-microm pulses that experience self-phase modulation in the fibers. The resultant induced grating autocorrelation response yields a value of n2/A(eff) and a calibration standard for the fiber. A phase shift of the order of 0.19pi can be detected and is limited only by laser amplitude fluctuations. A unique advantage of this technique is its ability to measure n2 accurately in short lengths (z < or = 25 m) of fiber, whereas other approaches typically use much longer lengths of fiber (z > or = 100 m).     

Measurement of branching fractions and mass spectra of B-->Kpipigamma

We present a measurement of the partial branching fractions and mass spectra of the exclusive radiative penguin processes B-->Kpipigamma in the range m(Kpipi)<1.8 GeV/c(2). We reconstruct four final states: K(+)pi(-)pi(+)gamma, K(+)pi(-)pi(0)gamma, K(S)(0)pi(-)pi(+)gamma, and K(S)(0)pi(+)pi(0)gamma, where K(S)(0)-->pi(+)pi(-). Using 232 x 10(6) e(+)e(-)-->BB events recorded by the BABAR experiment at the SLAC PEP-II asymmetric-energy storage ring, we measure the branching fractions B(B(+)-->K(+)pi(-)pi(+)gamma)=[2.95+/-0.13(stat)+/-0.20(syst)] x 10(-5), B(B(0)-->K(+)pi(-)pi(0)gamma)=[4.07+/-0.22(stat)+/-0.31(syst)] x 10(-5), B(B(0)-->K(0)pi(+)pi(-)gamma)=[1.85+/-0.21(stat)+/-0.12(syst)] x 10(-5), and B(B(+)-->K(0)pi(+)pi(0)gamma)=[4.56+/-0.42(stat)+/-0.31(syst)] x 10(-5).     

Constructing Space for Science at the Royal Institution of Great Britain

Those who have worked in the Royal Institution of Great Britain have, since its foundation in 1799, made significant contributions to scientific knowledge, to its practical application, and to its communication to a wide variety of audiences. Such work cannot be carried out in an architectural vacuum, and in this paper we examine how the buildings of the Royal Institution, 20 and 21 Albemarle Street in central London, have shaped the work undertaken within its walls and how, on a number of occasions, the buildings have been reconfigured to take account of the evolving needs of scientific research and communication. This paper is based on the Conservation Plan of the Royal Institution that we wrote during 2003. The Conservation Plan did not examine the land owned by the Royal Institution to the north (i.e., 22 and 23 Albemarle Street; for this area see Richard Garnier, “Grafton Street, Mayfair,” Georgian Group Journal 13 (2003), 210–272), but it did discuss 18 and 19 Albemarle Street. In this paper we concentrate on the core Royal Institution buildings at 20 and 21 Albemarle Street. Other studies of the relationship of architecture,space, and science include Crosbie Smith and Jon Agar, ed., Making Space for Science: Territorial Themes in the Shaping of Knowledge (Basingstoke: Macmillan, 1997); Peter Galison and Emily Thompson, ed., The Architecture of Science (Cambridge, Mass.: MIT Press, 1999); and Sophie Forgan,“The architecture of science and the idea of a university,” Studies in History and Philosophy of Science 20 (1989), 405–434. Frank A.J.L. James is Professor of the History of Science at the Royal Institution; he has written widely on the history of nineteenth-century science in its social and cultural contexts and is editor of the Correspondence of Michael Faraday. He is President of the British Society for the History of Science. Anthony Peers is an Associate of Rodney Melville and Partners where he works in the field of building conservation as an architectural historian. He is a Council member of the Ancient Monument Society.     

Interaction of H2S with α-Fe2O3(0 0 0 1) surface

The atomic-scale structural changes in an α-Fe₂O₃ (hematite) (0 0 0 1) surface induced by sulfidation and subsequent oxidation processes were studied by X-ray photoemission spectroscopy, LEED, and X-ray standing wave (XSW) measurements. Annealing the α-Fe₂O₃(0 0 0 1) with a H₂S partial pressure of 1 × 10⁻⁷ Torr produced iron sulfides on the surface as the sulfur atoms reacted with the substrate Fe ions. The oxidation state of the substrate Fe changed from 3+ to 2+ as a result of the sulfidation. The XSW measured distance of the sulfur atomic-layer from the unrelaxed substrate oxygen layer was 3.16 Å. The sulfide phase consisted of three surface domains identified by LEED. Formation of the two-dimensional FeS₂ phase with structural parameters consistent with an outermost layer of (1 1 1) pyrite has been proposed. Atomic oxygen exposure oxidized the surface sulfide to a sulfate () and regenerated the α-Fe₂O₃(0 0 0 1) substrate, which was indicated by a (1 × 1) LEED pattern and the re-oxidization of Fe to 3+.