[en] A spin-transparent beam kicker is proposed for allowing a terrain following design of a very large ring without destroying beam polarization

[en] In a bold move to boost US high energy physics. President Reagan has approved construction of the world's largest particle accelerator, the Superconducting Supercollider, SSC. With the requested start in Financial Year 1988, the Supercollider could be completed in 1996. The actual timetable depends on Congressional approval and actual levels of funding

[en] The running scenarios of the LHCb experiment in the early operation period of the LHC are discussed in view of the foreseen machine evolution. Aligment of the overall detector and its calibration will be the primary concern of the first runs; the strategy to perform them is described. The experiment aims to be in a stable running condition as soon as possible. Some of the measurements with the data collected in the first months of operation at a 14 TeV collision energy are outlined

[en] The main goal of the ALICE experiment at LHC is to study strongly interacting matter at high energy densities, especially signatures and properties of the quark-gluon plasma. This goal manifests itself in a rich physics program. Although ALICE is mainly designed to study heavy-ion collisions, a dedicated program will concentrate on proton-proton physics. The talk will introduce the capabilities of ALICE to contribute to the field of p+p physics at the LHC. Two unique properties are its low p_T cut-off and the excellent PID capabilities. The various topics of the proton-proton physics program, which will allow a close scrutiny of existing theoretical models, will be described. Furthermore, the interpretation of measurements of heavy-ion collisions necessitates the comparison to measurements of p+p collisions. At startup, neither the LHC luminosity nor its energy will have their nominal values. Still several physics topics can be studied from the very beginning. These ''day-1'' physics topics will be presented as well as the effort that is already ongoing to be ready for the first collision. (orig.)

[en] Two-loop contributions to the muon (g−2) from fermion/sfermion loops in the MSSM are presented, and an overview of the full MSSM prediction for (g−2) is given with emphasis on the behaviour in scenarios which are compatible with LHC data, including scenarios with large mass splittings. Compared to all previously known two-loop contributions, the fermion/sfermion loop contributions can yield the largest numerical results. The new contributions contain the important universal quantities Δα and Δρ, and for large sfermion masses the contributions are non-decoupling and logarithmically enhanced. We find up to 15% (30%) corrections for sfermion masses in the 20 TeV (1000 TeV) range

[en] The design and characteristics of detectors applicable at 20 TeV are discussed, followed by detector considerations for a high luminosity hadron-hadron machine

[en] We calculate the complete-NLO predictions for $t\stackrel{¯<!--\; ??\; -->}{t}{W}^{\pm <!--\; ??\; -->}$ and $t\stackrel{¯<!--\; ??\; -->}{t}t\stackrel{¯<!--\; ??\; -->}{t}$ production in proton-proton collisions at 13 and 100 TeV. All the non-vanishing contributions of $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^i{\mathrm{\alpha <!--\; ??\; -->}}^j)$ with $i+j=3,4$ for $t\stackrel{¯<!--\; ??\; -->}{t}{W}^{\pm <!--\; ??\; -->}$ and $i+j=4,5$ for $t\stackrel{¯<!--\; ??\; -->}{t}t\stackrel{¯<!--\; ??\; -->}{t}$ are evaluated without any approximation. For $t\stackrel{¯<!--\; ??\; -->}{t}{W}^{\pm <!--\; ??\; -->}$ we find that, due to the presence of $tW\to <!--\; ???\; -->tW$ scattering, at 13(100) TeV the $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s{\mathrm{\alpha <!--\; ??\; -->}}^3)$ contribution is about 12(70)% of the LO, i.e., it is larger than the so-called NLO EW corrections (the $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^2{\mathrm{\alpha <!--\; ??\; -->}}^2)$ terms) and has opposite sign. In the case of $t\stackrel{¯<!--\; ??\; -->}{t}t\stackrel{¯<!--\; ??\; -->}{t}$ production, large contributions from electroweak $tt\to <!--\; ???\; -->tt$ scattering are already present at LO in the $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^3\mathrm{\alpha <!--\; ??\; -->})$ and $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^2{\mathrm{\alpha <!--\; ??\; -->}}^2)$ terms. For the same reason we find that both NLO terms of $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^4\mathrm{\alpha <!--\; ??\; -->})$, i.e., the NLO EW corrections, and $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^3{\mathrm{\alpha <!--\; ??\; -->}}^2)$ are large ($\pm <!--\; ??\; -->15\mathrm{\%<!--\; \%\; -->}$ of the LO) and their relative contributions strongly depend on the values of the renormalisation and factorisation scales. However, large accidental cancellations are present (away from the threshold region) between these two contributions. Moreover, the NLO corrections strongly depend on the kinematics and are particularly large at the threshold, where even the relative contribution from $\mathcal{O}({\mathrm{\alpha <!--\; ??\; -->}}_s^2{\mathrm{\alpha <!--\; ??\; -->}}^3)$ terms amounts to tens of percents.

[en] An accelerator that crosses the Fermilab site boundary must have a minimum effect on the surrounding environment and the people residing in the area. Unobstructed public access should be allowed above the ring except in relatively few areas such as the injection, dump, and experimental regions. The accelerator should be a benign and unobtrusive neighbor not only when it is completed but also in the construction period. For these reasons underground tunneling for all or most of the ring seems attractive. In this note we look into some questions raised by tunneling beyond the Fermilab site. Most of our discussion is of general applicability. However, we will use as examples two specific ring configurations. The examples have not been optimized from the point of view of physics output or accelerator technology but are just specific examples which allow us to study questions of tunneling. One is a ring of 5 km radius (5 TeV) tangent to the Tevatron and entirely east of the Fox River and fed by a beam from the Tevatron which crosses under the river. We assume that each of these machines will have 100 beam fills per year and we scale the maximum intensities with the accelerator radii. Thus we assume that there will be 1.0 E14 protons in each beam of the 20 TeV machine and 2.5 E13 for the 5 TeV machine

[en] Constraints on new physics from collider searches are usually presented in terms of so-called simplified models. However, because simplified models only consider a very small number of degrees of freedom of a more complete fundamental extension of the standard model, they are likely to provide an incomplete picture. To evaluate the impact of new physics searches more broadly, interpretations are made in terms of full models like the phenomenological Minimal Supersymmetric Standard Model (pMSSM). An integral part of such an analysis is a scan of the parameter space. In this talk, results from previous pMSSM scans are reviewed and a new parameter scan is presented as the basis of a run II pMSSM interpretation by the CMS experiment.

[en] In the Standard Model, there are many striking similarities between the quark and the lepton sector, like the number of families and the mass hierarchy between them. Leptoquarks are hypothetical particles that occur in various models for physics beyond the Standard Model and provide a connection between the two sectors. They are commonly assumed to couple to quarks and leptons of the same fermion generation but this need not be the case. This contribution gives an overview of the motivation for and presents important aspects of the search for scalar leptoquarks performed by the ATLAS collaboration using proton-proton collision data collected at a centre-of-mass energy of √(s) = 13 TeV.