125602943
Is V($_{tb}$) $\simeq$ 1?
119405269
Trace anomalies and the Delta I = 1/2 rule
Trace Anomaly Dominance in weak $K$-decays successfully reproduces the $\Delta I = {1\over 2}$ selection rule results, as observed in $K_S \to \pi\pi, K_L \to \pi\pi\pi, K_S \to \gamma\gamma$ and $K_L \to \pi^0 \gamma\gamma$. Comment: 10 pages, no figure
117864746
The Delta I = 1/2 Rule in the Large N Limit
The large-N limit is used to obtain a consistent picture of the K → ππ matrix elements. It is confirmed that the dominant Q6 penguin matrix elements are enhanced by an order of magnitude compared to those of the current-current operators and that this result is consistent with chiral perturbation theory. An additional enhancement of the penguin contributions is identified with respect to standard estimates which comes from an incomplete GIM cancellation above the charm quark mass. Performing the short-distance analysis to first nontrivial order in 1/N its validity and simplicity is demonstrated. Encouraging results are obtained for A(K → ππ) amplitudes and it is pointed out that further improvements can be obtained through the inclusion of the low-energy evolution which necessarily must be done in a meson rather than a quark picture.
120345777
Geometrical T-violation
We investigate the possibility of having spontaneous T violation arising from complex vacuum expectation values with calculable phases, assuming geometrical values, entirely determined by the symmetry of the scalar potential.
122137370
The B parameter beyond the leading order of the 1/n expansion
We calculate the next-to-leading Image corrections to the B parameter which measures the size of the ΔS=2 matrix element Image . These corections turn out to be small which assures the validity of the 1/N expansion. For ΛQCD=0.3GeV we find B=0.66±0.10 to be compared with the leading order value B=0.75. We clarify the differences between these results and the results of the usual chiral perturbative calculations which give Image at the tree level but appear to signal the breakdown of chiral perturbation theory at the one-loop level.
118374875
Flavor mixing democracy and minimal CP violation
We point out that there is a unique parametrization of quark flavor mixing in which every angle is close to the Cabibbo angle theta(C) similar or equal to 13 degrees with the CP-violating phase phi(q) around 1 degrees, implying that they might all be related to the strong hierarchy among quark masses. Applying the same parametrization to lepton flavor mixing, we find that all three mixing angles are comparably large (around pi/4) and the Dirac CP-violating phase phi(l) is also minimal as compared with its values in the other eight possible parametrizations. In this spirit, we propose a simple neutrino mixing ansatz which is equivalent to the tri-bimaximal flavor mixing pattern in the phi(l) -> 0 limit and predicts sin theta(13) = 1/root 2sin(phi(l)/2) for reactor antineutrino oscillations. Hence the Jarlskog invariant of leptonic CP violation J(l) = (sin phi(l)/12) can reach a few percent if theta(13) lies in the range 7 degrees <= theta(13) <= 10 degrees. (C) 2012 Elsevier B.V. All rights reserved.
108673538
THE CERN TRACK-MATCH PROGRAM FOR VERTEX GUIDANCE BUBBLE CHAMBER MEASUREMENT SYSTEMS.
195705202
Local area networks for microcomputers
Abstract This paper analyses the ways in which modern high performance Local Area Networks (LANs) can be of use to microcomputers. It discusses some of the basic concepts of LANs, with special reference to international standards. It then presents ways in which LANs may be connected to, and used with microcomputers. Examples are given of existing applications.
108010999
The development and use of a high speed packet switching network in a high-energy physics laboratory
53610914
HST/ACS Observations of Europa's Atmospheric UV Emission at Eastern Elongation
We report results of a Hubble Space Telescope (HST) campaign with the Advanced Camera for Surveys to observe Europa at eastern elongation, i.e. Europa's leading side, on 2008 June 29. With five consecutive HST orbits, we constrain Europa's atmospheric \ion{O}{1} 1304 \A and \ion{O}{1} 1356 \A emissions using the prism PR130L. The total emissions of both oxygen multiplets range between 132 $\pm$ 14 and 226 $\pm$ 14 Rayleigh. An additional systematic error with values on the same order as the statistical errors may be due to uncertainties in modelling the reflected light from Europa's surface. The total emission also shows a clear dependence of Europa's position with respect to Jupiter's magnetospheric plasma sheet. We derive a lower limit for the O$_2$ column density of 6 $\times$ 10$^{18}$ m$^{-2}$. Previous observations of Europa's atmosphere with STIS in 1999 of Europa's trailing side show an enigmatic surplus of radiation on the anti-Jovian side within the disk of Europa. With emission from a radially symmetric atmosphere as a reference, we searched for an anti-Jovian vs sub-Jovian asymmetry with respect to the central meridian on the leading side, and found none. Likewise, we searched for departures from a radially symmetric atmospheric emission and found an emission surplus centered around 90 degree west longitude, for which plausible mechanisms exist. Previous work about the possibility of plumes on Europa due to tidally-driven shear heating found longitudes with strongest local strain rates which might be consistent with the longitudes of maximum UV emissions. Alternatively, asymmetries in Europa's UV emission can also be caused by inhomogeneous surface properties, inhomogeneous solar illuminations, and/or by Europa's complex plasma interaction with Jupiter's magnetosphere.
118467793
THE STATUS OF CERN--RHEL MINIMUM GUIDANCE.