[en] This paper presents a concise summary of the developments achieved in the context of the 'Photons' Working Group of the 1991 ECFA Workshop on Physics with Linear Colliders. After reviewing, in Section 2, the current knowledge in the beam-beam interaction and its main physics implications, we calculate in Section 3 effective photon and electron luminosity spectra. Section 4 discusses background issues associated with photon-photon processes. Finally, we briefly survey, in Section 5, recent updates on the principle issues and the physics potential of the so-called 'Compton Collider'. (orig.)

[en] We review theoretical and experimental results relevant to charm and bottom physics. In particular, we consider charmonium and open heavy-flavour production at Tevatron, LEP and HERA colliders, and in heavy-ion scattering. We study the prospect of future b-physics measurement at the LHC with the ATLAS and CMS detectors. (author)

[en] We present the FP420 R and D project, which has been studying the key aspects of the development and installation of a silicon tracker and fast-timing detectors in the LHC tunnel at 420 m from the interaction points of the ATLAS and CMS experiments. These detectors would measure precisely very forward protons in conjunction with the corresponding central detectors as a means to study Standard Model (SM) physics, and to search for and characterise new physics signals. This report includes a detailed description of the physics case for the detector and, in particular, for the measurement of Central Exclusive Production, pp→p+φ+p, in which the outgoing protons remain intact and the central system φ may be a single particle such as a SM or MSSM Higgs boson. Other physics topics discussed are γγ and γp interactions, and diffractive processes. The report includes a detailed study of the trigger strategy, acceptance, reconstruction efficiencies, and expected yields for a particular pp→pHp measurement with Higgs boson decay in the b b-bar mode. The document also describes the detector acceptance as given by the LHC beam optics between the interaction points and the FP420 location, the machine backgrounds, the new proposed connection cryostat and the moving ('Hamburg') beam-pipe at 420 m, and the radio-frequency impact of the design on the LHC. The last part of the document is devoted to a description of the 3D silicon sensors and associated tracking performances, the design of two fast-timing detectors capable of accurate vertex reconstruction for background rejection at high-luminosities, and the detector alignment and calibration strategy.

[en] Charm production in charged current deep inelastic scattering has been measured for the first time in e^±p collisions, using data collected with the ZEUS detector at HERA, corresponding to an integrated luminosity of 358 pb⁻¹. Results are presented separately for e⁺p and e⁻p scattering at a centre-of-mass energy of $\sqrt{s}$ = 318 GeV within a kinematic phase-space region of 200 GeV² < Q² < 60000 GeV² and y < 0.9, where Q² is the squared four-momentum transfer and y is the inelasticity. The measured cross sections of electroweak charm production are consistent with expectations from the Standard Model within the large statistical uncertainties.