Search for the rare decays B+→μ+μ-K+, B0→μ+μ- K*(892)0, and Bs0→μ+μ- at CDF
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:1 (2009)
Abstract:
We search for b→sμ+μ- transitions in B meson (B+, B0, or Bs0) decays with 924pb-1 of pp̄ collisions at s=1.96TeV collected with the CDF II detector at the Fermilab Tevatron. We find excesses with significances of 4.5, 2.9, and 2.4 standard deviations in the B+→μ+μ-K+, B0→μ+μ-K*(892)0, and Bs0→μ+μ- decay modes, respectively. Using B→J/ψh (h=K+, K*(892)0,) decays as normalization channels, we report branching fractions for the previously observed B+ and B0 decays, B(B+→μ+μ-K+)=(0.59±0.15±0. 04)×10-6, and B(B0→μ+μ-K*(892)0)=(0.81±0. 30±0.10)×10-6, where the first uncertainty is statistical, and the second is systematic. We set an upper limit on the relative branching fraction B(Bs0→μ+μ-)/B(Bs0→J/ψ)<2.6(2.3)×10-3 at the 95(90)% confidence level, which is the most stringent to date. © 2009 The American Physical Society.A measurement of the Q2, W and t dependences of deeply virtual Compton scattering at HERA
Journal of High Energy Physics 2009:5 (2009)
Abstract:
Deeply virtual Compton scattering, γ*p→γp has been measured in e+p collisions at HERA with the ZEUS detector using an integrated luminosity of 61.1 pb-1. Cross sections are presented as a function of the photon virtuality, Q2, and photon-proton centre-of-mass energy, W, for a wide region of the phase space, Q2 > 1.5GeV2 and 40 < W < 170GeV. A subsample of events in which the scattered proton is measured in the leading proton spectrometer, corresponding to an integrated luminosity of 31.3 pb-1, is used for the first direct measurement of the differential cross section as a function of t, where t is the square of the four-momentum transfer at the proton vertex. © SISSA 2009.In-situ Storage Image Sensor for a vertex detector at the ILC
Proceedings of Science 95 (2009)
Abstract:
In-situ Storage Image Sensor (ISIS) is a new detector concept being developed by the Linear Collider Flavour Identification collaboration for a future vertex detector at the ILC. ISIS1 was the first prototype and was used to test the operational principles. ISIS2 is the second generation of the family, and is made on a submicron CMOS process to reduce the pixel size. Characterisation of the test structures built along with the main part of the sensor array are reported here, including the readout noise, the cell well-capacity and the fringing-field effects. Preliminary results of the test on the main array are also discussed. The results indicate that ISIS is an extremely promising design for the ILC.Leading proton production in deep inelastic scattering at HERA
Journal of High Energy Physics 2009:6 (2009)
Abstract:
The semi-inclusive reaction e+p→e+Xp was studied with the ZEUS detector at HERA with an integrated luminosity of 12.8 pb -1. The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, xL > 0.32, and its transverse momentum squared satisfied p 2T < 0.5GeV2; the exchanged photon virtuality, Q2, was greater than 3GeV2 and the range of the masses of the photon-proton system was 45 < W < 225GeV. The leading proton production cross section and rates are presented as a function of xL, p2 T , Q2 and the Bjorken scaling variable, x. © SISSA 2009.Measurement of beauty photoproduction using decays into muons in dijet events at HERA
Journal of High Energy Physics 2009:4 (2009)