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.
119799537
A Consistent Analysis of the Delta I = 1/2 Rule for K Decays
We calculate the hadronic matrix elements of local operators relevant to the K→ππ decays using the 1/N expansion. This approach permits a consistent treatment of both short-and long-distance effects. The latter provide important contributions to the enhancement and suppression of the Image and ΔI = 3/2 amplitudes, respectively. A satisfactory description of the observed data can be achieved within the standard model.
15156751
Mass Issues in Fundamental Interactions
Driven by the mass problem, we raise some issues of the fundamental interactions in terms of non trivial commutation relations implemented within toy theories.
120740308
On strong physics in weak decays
Abstract We comment on some effects of strong physics in strange, charm and beauty weak decays. Measured decays indicative where a description in terms of hadrons is more appropriate than the quark-gluon perturbative language.
120251745
1/n Expansion for Kaons
Abstract We calculate various parameters of the kaon system in the leading order in 1/ N expansion, ( N being the number of colors). We find that dropping the non-leading terms enhances the ratio A (K → ππ ( I = 0))/ A (K → ππ ( I = 2)) by an additional factor 1.5 which together with the usual short-distance enhancement and penguin contributions helps in explaining the ΔI = 1 2 rule. The B parameter is found to be 3 4 , the long-distance contribution to the K L − K S mass difference ΔM is positive and amounts to 30% of the measured value. The corresponding long-distance contribution to e is at most 10%. The experimental data for e and ΔM can easily be reproduced but e′/e is found to be O(10 −2 ) if the ΔI = 1 2 rule is to be respected. The K L → γγ amplitude is reproduced and gives rise to a small CP -violating effect.
119667263
The Attractor mechanism in the minimal tensor - scalar theory of gravity
In a previous letter, we proved that the minimal tensor–scalar theory of gravity with a spatially flat Einstein metric does not generically contain an attractor mechanism towards general relativity. Hereafter we extend our proof to the case of a spatially curved Einstein metric.
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.
107816989
Performance of the HPD minimum guidance systeme, pt 1
122062189
Two years of real progress in European HEP networking : a CERN perspective
Abstract The last two years have been marked by real progress in networking in HEP. Home-made developments, studies and plans have given way to the use of real networks involving hundreds of HEP and other computers and based on externally produced software and hardware. Within the last year, the first generation of industrial software products following some of the international standards for networking have become available. Related developments are taking place in networking for on-line systems and indeed the LEP experiments are distinguished by their heavy and crucial reliance on both local and wide-area networks. This paper describes the progress made at CERN since the last two years and looks at perspectives for the future.
108673538
THE CERN TRACK-MATCH PROGRAM FOR VERTEX GUIDANCE BUBBLE CHAMBER MEASUREMENT SYSTEMS.
108010999
The development and use of a high speed packet switching network in a high-energy physics laboratory