Forward Physics at the LHC (Elba 2010)

The papers review the main theoretical and experimental aspects of the Forward Physics at the Large Hadron Collider

Determination of absolute neutrino masses from Z-bursts

Ultrahigh energy neutrinos (UHE\nu) scatter on relic neutrinos (R\nu) producing Z bosons, which can decay hadronically producing protons (Z-burst). We compare the predicted proton spectrum with the observed ultrahigh energy cosmic ray (UHECR) spectrum and determine the mass of the heaviest R\nu via a maximum likelihood analysis. Our prediction depends on the origin of the power-like part of the UHECR spectrum: m_\nu=2.75^{+1.28}_{-0.97} eV for Galactic halo and 0.26^{+0.20}_{-0.14} eV for extragalactic (EG) origin. The necessary UHE\nu flux should be detected in the near future.Comment: slight rewording, revised neutrino fluxes, conclusions unchanged, version to appear in Phys. Rev. Let

Spectrum and Charge Ratio of Vertical Cosmic Ray Muons up to Momenta of 2.5 TeV/c

The ALEPH detector at LEP has been used to measure the momentum spectrum and charge ratio of vertical cosmic ray muons underground. The sea-level cosmic ray muon spectrum for momenta up to 2.5 TeV/c has been obtained by correcting for the overburden of 320 meter water equivalent (mwe). The results are compared with Monte Carlo models for air shower development in the atmosphere. From the analysis of the spectrum the total flux and the spectral index of the cosmic ray primaries is inferred. The charge ratio suggests a dominantly light composition of cosmic ray primaries with energies up to 10^15 eV

Space, Time and Color in Hadron Production Via e+e- -> Z0 and e+e- -> W+W-

The time-evolution of jets in hadronic e+e- events at LEP is investigated in both position- and momentum-space, with emphasis on effects due to color flow and particle correlations. We address dynamical aspects of the four simultanously-evolving, cross-talking parton cascades that appear in the reaction e+e- -> gamma/Z0 -> W+W- -> q1 q~2 q3 q~4, and compare with the familiar two-parton cascades in e+e- -> Z0 -> q1 q~2. We use a QCD statistical transport approach, in which the multiparticle final state is treated as an evolving mixture of partons and hadrons, whose proportions are controlled by their local space-time geography via standard perturbative QCD parton shower evolution and a phenomenological model for non-perturbative parton-cluster formation followed by cluster decays into hadrons. Our numerical simulations exhibit a characteristic `inside-outside' evolution simultanously in position and momentum space. We compare three different model treatments of color flow, and find large effects due to cluster formation by the combination of partons from different W parents. In particular, we find in our preferred model a shift of several hundred MeV in the apparent mass of the W, which is considerably larger than in previous model calculations. This suggests that the determination of the W mass at LEP2 may turn out to be a sensitive probe of spatial correlations and hadronization dynamics.Comment: 52 pages, latex, 18 figures as uu-encoded postscript fil

Performance of the Beetle readout chip for LHCb

Beetle is a 128-channel readout chip, which will be used in the silicon vertex detector, the pile-up veto counters and the silicon tracker of the LHCb experiment at CERN. A further application of the Beetle chip is the readout of the LHCb RICH, in case it is equipped with multi-anode PMTs. The scope of this paper is the design changes leading to the latest version 1.3 of the Beetle readout chip. In addition, measurements on earlier versions and simulation results driving these changes are shown

SEU Robustness, Total Dose Radiation Hardness and Analogue Performance of the Beetle Chip

The Beetle is a 128 channel readout chip for silicon strip detectors in LHCb. In addition to the pipelined readout path known from the RD20 architecture which can be used either in analogue or binary mode, the Beetle features an additional prompt binary readout path, used for the LHCb pile-up veto counters and a triple-redundant layout of the control logic. It is manufactured in commercial 0.25 µm CMOS technology using radiation hard design techniques. In addition to a total dose irradiation with X-rays, an SEU irradiation test with 65 MeV protons was performed with Beetle1.3. The results of this test are presented together with new results from the Beetle versions 1.3, 1.4 and 1.5, which were submitted in the Beetle ER engineering run in May 2004

Experiments to Find or Exclude a Long-Lived, Light Gluino

Gluinos in the mass range ~1 1/2 - 3 1/2 GeV are absolutely excluded. Lighter gluinos are allowed, except for certain ranges of lifetime. Only small parts of the mass-lifetime parameter space are excluded for larger masses unless the lifetime is shorter than ~ 2 10^{-11} (m_{gluino}/ GeV) sec. Refined mass and lifetime estimates for R-hadrons are given, present direct and indirect experimental constraints are reviewed, and experiments to find or definitively exclude these possibilities are suggested.Comment: 27 pp, latex with 1 uufiled figure, RU-94-35. New version amplifies discussion of some points and corresponds to version for Phys. Rev.

Enhanced Radiation Hardness and Faster Front Ends for the Beetle Readout Chip

This paper summarizes the recent progress in the development of the 128 channel pipelined readout chip Beetle, which is intended for the silicon vertex detector, the inner tracker, the pile-up veto trigger and the RICH detectors of LHCb. Deficiencies found in the front end of the Beetle Version 1.0 and 1.1 chips resulted in the submissions of BeetleFE 1.1 and BeetleFE 1.2, while BeetleSR 1.0 implements test circuits to provide future Beetle chips with logic circuits hardened against single event upset (SEU). Section I. motivates the development of new front ends for the Beetle chip, and section II. summarizes their concepts and construction. Section III. reports preliminary results from the BeetleFE 1.1 and BeetleFE 1.2 chips, while section IV. describes the BeetleSR 1.0 chip. An outlook on future test and development of the Beetle chip is given in section V

Standard Model Physics at LEP

Selected topics on precision tests of the Standard Model of the Electroweak and the Strong Interaction at the LEP $e^+e^-$ collider are presented, including an update of the world summary of measurements of $\alpha_s$, representing the state of knowledge of summer 1999. This write-up of lecture notes consists of a reproduction of slides, pictures and tables, supplemented by a short descriptive text and a list of relevant references.Comment: lecture given at Intern. Summer School at Nijmegen, August 1999, 44 pages, 36 (mostly coloured) figures, LaTeX, needs crckapb.st