This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton ...sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
A new measurement of the b ¯ b production cross section in 920 GeV proton-nucleus collisions is presented by the HERA-B Collaboration. The b ¯ b production is tagged via inclusive bottom quark decays ...into J / ψ mesons by exploiting the longitudinal separation of J / ψ → l + l − decay vertices from the primary proton-nucleus interaction point. Both e + e − and μ + μ − channels are reconstructed for a total of 83 ± 12 inclusive b → J / ψ X events found. The combined analysis yields a b ¯ b to prompt J / ψ cross section ratio of Δ σ ( b ¯ b ) Δ σ J / ψ = 0.032 ± 0.005 stat ± 0.004 sys measured in the x F acceptance ( − 0.35 < x F < 0.15 ), extrapolated to σ ( b ¯ b ) = 14.9 ± 2.2 stat ± 2.4 sys nb/nucleon in the total phase space.
The Proceedings of the 2003 SLAC Workshops on flavor physics with a high
luminosity asymmetric e+e- collider. The sensitivity of flavor physics to
physics beyond the Standard Model is addressed in ...detail, in the context of the
improvement of experimental measurements and theoretical calculations.
The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B ...spectrometer covers negative values of
x
F
up to
x
F
=
−
0.3
and a broad range in transverse momentum from 0.0 to 4.8GeV/
c. The studies presented in this paper include
J
/
ψ
differential distributions and the suppression of
J
/
ψ
production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.
The Proceedings of the 2003 SLAC Workshops on flavor physics with a high luminosity asymmetric e+e- collider. The sensitivity of flavor physics to physics beyond the Standard Model is addressed in ...detail, in the context of the improvement of experimental measurements and theoretical calculations.
Advanced heavy ion beam probe (HIBP) operates on the T-10 tokamak with 20–130 μA Tl+ beam accelerated up to 330 keV. The HIBP has a unique capability to measure the mean value of the core plasma ...potential, and the oscillations in potential φ, density ne and poloidal magnetic field simultaneously in 5 spatially separated sample volumes for OH and ECRH plasmas with n¯e=(0.3−5)×1019 m−3, 100<Ipl<330 kA. Time evolution of local plasma parameters and/or radial profiles can be measured in a single shot. The profile in the range 0.25<ρ<1 is available shot by shot for B0<2.2 T. The paper describes main elements of hardware: injector, beamlines, control systems, analyzer, power supplies, and software for HIBP. Physical examples show that HIBP can measure the cross-phase of density oscillations, the poloidal phase velocity of turbulence rotation, the poloidal electric field and the radial turbulent particle flux. Spectral analysis allows us to distinguish various types of turbulence, such as broadband (<500 kHz), quasicoherent, tearing and geodesic acoustic modes.
We have searched for Theta^+(1540) and Xi^{--}(1862) pentaquark candidates in proton-induced reactions on C, Ti and W targets at mid-rapidity and \sqrt{s} = 41.6 GeV. In 2x10^8 inelastic events we ...find no evidence for narrow (sigma~5 MeV) signals in the Theta^+ -> pK_s and Xi^{--} -> Xi^-pi^- channels: our 95% CL upper limits (UL) for the inclusive production cross section times branching fraction Bx(dsigma/dy)|_{y~0} are 3.7 and 2.5 microb/N. The UL of the yield ratio of Theta^+ / Lambda(1520) < 2.7% is significantly lower than model predictions. Our UL of BxXi^{--} / Xi(1530)^0 < 4% is at variance with the results that have provided first evidence for the Xi^{--} signal.
Inclusive differential cross sections $d\sigma_{pA}/dx_F$ and $d\sigma_{pA}/dp_t^2$ for the production of \kzeros, \lambdazero, and \antilambda particles are measured at HERA in proton-induced ...reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to $\sqrt {s} = 41.6$ GeV in the proton-nucleon system. The ratios of differential cross sections \rklpa and \rllpa are measured to be $6.2\pm 0.5$ and $0.66\pm 0.07$, respectively, for \xf $\approx-0.06$. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions $d\sigma_{pA}/dp_t^2$ also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections $\sigma_{pA}$ on the atomic mass $A$ of the target material is discussed, and the deduced cross sections per nucleon $\sigma_{pN}$ are compared with results obtained at other energies.
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