Near-threshold production of W±W^\pm, Z0Z^0 and H0H^0 at a fixed-target experiment at the future ultra-high-energy proton colliders

We outline the opportunities to study the production of the Standard Model bosons, $W^\pm$, $Z^0$ and $H^0$ at "low" energies at fixed-target experiments based at possible future ultra-high-energy proton colliders, \ie\ the High-Energy LHC, the Super proton-proton Collider and the Future Circular Collider -- hadron-hadron. These can be indeed made in conjunction with the proposed future colliders designed to reach up to $\sqrt{s}=100$ TeV by using bent crystals to extract part of the halo of the beam which would then impinge on a fixed target. Without disturbing the collider operation, this technique allows for the extraction of a substantial amount of particles in addition to serve for a beam-cleaning purpose. With this method, high-luminosity fixed-target studies at centre-of-mass energies above the $W^\pm$, $Z^0$ and $H^0$ masses, $\sqrt{s} \simeq 170-300$ GeV, are possible. We also discuss the possibility offered by an internal gas target, which can also be used as luminosity monitor by studying the beam transverse shape

Experimental investigations of the interaction of multi-GeV particles with strong crystalline fields and applications in high-energy beam lines

The thesis first introduces the theory of the interaction of energetic particles with strong crystalline fields. It then treats a number of experiments that investigate different phenomena which can be divided in two: Strong field effects and bent crystals. Both of these include a wealth of sub-topics, such as pair production, strong gamma-ray emission, radiative cooling, polarized gamma-rays and possible inhibiting effects as well as an investigation of the advantage of high-Z materials for deflection of charged particles in crystals and an examination of the radiation hardness of the deflection phenomenon. A number of used and potential applications are considered

Experimental Area of the CERN Antiproton Decelerator

The CERN Antiproton Decelerator will deliver low energy beams to four experimental beam-lines installed within the acceleratorcircumference. The limited space available imposes tight constraints on the topology of the beam-lines needed by the experimental devices. In this paper, the general layout of the experimental area is reviewed. Furthermore, a discussion of the so-called measurement line for tests and AD beam property measurements is included along with remarks on the optics of the reverse injection of protons, to be used for the commissioning

Experimental investigation of the Landau-Pomeranchuk-Migdal effect in low-Z targets

In the CERN NA63 collaboration we have addressed the question of the potential inadequacy of the commonly used Migdal formulation of the Landau-Pomeranchuk-Migdal (LPM) effect by measuring the photon emission by 20 and 178 GeV electrons in the range 100 MeV - 4 GeV, in targets of LowDensityPolyEthylene (LDPE), C, Al, Ti, Fe, Cu, Mo and, as a reference target, Ta. For each target and energy, a comparison between simulated values based on the LPM suppression of incoherent bremsstrahlung is shown, taking multi-photon effects into account. For these targets and energies, we find that Migdal's theoretical formulation is adequate to a precision of better than about 5%, irrespective of the target substance.Comment: 8 pages, 13 figure

Improved Crystal Method for Photon Beam Linear Polarization Measurement at High Energies

A method for photon linear polarization determination based on the measurement of the asymmetry of pairs produced by polarized photons in single crystals within the optimal intervals of pair particles energies is proposed. In difference to the well known methods the asymmetry in this case is essentially larger. The optimal orientation of crystal is found which provides the maximal values for analyzing power and figure of merit as well as minimal measurement time.Comment: 8 pages, 5 figure

What did we learn from the extraction experiments with bent crystals at the CERN SPS?

The feasibility and properties of particle extraction from an accelerator by means of a bent crystal were studied extensively at the CERN SPS. The main results of the experiments are presented. This includes the evidence for multipass extraction of heavy ions. These results are compared with theoretical expectations and computer simulations