89614484
Searching for new physics in the three-body decays of the Higgs-like particle
A bstractWe show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there is information that is lost upon integration, which can be uncovered in the differential decay widths. Concentrating on the decay h → Zℓ$ \overline{\ell} $, we identify the regions in the three-body phase space in which these effects become especially pronounced and could be detected in future experiments.
2024174
Bottom-quark forward-backward asymmetry in the standard model and beyond.
We computed the bottom-quark forward-backward asymmetry at the Tevatron in the standard model (SM) and for several new physics scenarios. Near the Z pole, the SM bottom asymmetry is dominated by tree level exchanges of electroweak gauge bosons. While above the Z pole, next-to-leading order QCD dominates the SM asymmetry as was the case with the top-quark forward-backward asymmetry. Light new physics, M(NP)≲150  GeV, can cause significant deviations from the SM prediction for the bottom asymmetry. The bottom asymmetry can be used to distinguish between competing new physics (NP) explanations of the top asymmetry based on how the NP interferes with s-channel gluon and Z exchange.
56563443
On Limit Cycles in Supersymmetric Theories
Abstract Contrary to popular belief conformality does not require zero beta functions. This follows from the work of Jack and Osborn, and examples in non-supersymmetric theories were recently found by some of us. In this Letter we show that such examples are absent in unitary N = 1 supersymmetric four-dimensional field theories. More specifically, we show to all orders in perturbation theory that the beta-function vector field of such theories does not admit limit cycles. A corollary of our result is that unitary N = 1 supersymmetric four-dimensional theories cannot be superscale-invariant without being superconformal.
117827083
Modification to footprint to accommodate an external fixed-target hall
Based on a note from C.T. Murphy on SSC Crystal Extracted Beams, we propose a modification to the footprint for the East Campus to accommodate an external beam area for 20-TeV protons. Because Murphy`s analysis uses a somewhat out-of-date ring configuration, it had to be modified to fit the current machine parameters. However, the same principles were applied. (The revised Murphy note of 9/16/89 uses the current machine parameters and is consistent with this memo.) Basically, to avoid sitting in the halo of the hewn from IR6 and IR7, the external proton hall must sit 9000 ft downstream of the center of the utility straight on the East Campus. For a crystal-extracted beam of 108 protons per second, the beam would simply drift this entire distance to the experimental hall. Some quads might be installed if necessary to transport the beam to the ham or to shape the beam. If at some time in the future the full SSC were to be extracted, this drift could be used to form secondary beamlines for very-high-energy, fixed-target experiments with pion, kaon, or muon beams. In order to accommodate the possibility of full beam extraction, the muon vectors were chosen to be 17,000 more » ft long. The control of the land for this distance assures that no radiation will be allowed to leave the site, regardless of how the program might evolve in the future. This land need only be procured under stratified fee. At the end of this area, some land could be procured on a fee simple basis to provide a space for radiation monitors. This area could also be used ultimately for a future neutrino experiment. « less
121903889
The Design and Performance of a Halo Free Intense Extracted Proton Beam at Fermilab
Abstract A set of refocussing and collimation stages has been constructed in the Proton West beam line of the Proton Area at Fermi National Accelerator Laboratory which allows the operation of a halo-free intense proton beam. Measurements made at the first target point in the Proton West experimental hall demonstrate that this system is capable of targeting 10 12 pprotons in a 4 mm diameter spot with a halo density of about 150 particle/mm 2 at a distance of 5.6 cm from the focus. This system has been operated at 200, 300, and 400 GeV.
122070076
Muon trigger electronics for hadron collider experiments
Abstract Trigger electronics designed and constructed for the SDC muon system are described briefly and results of beam tests carried out at KEK are presented. The implementation is based on custom VLSI designs in 1.2 μm CMOS. The performance characteristics of the circuits were measured and confirmed to meet specifications. Designs based on this approach are applicable to future collider experiments.
138778407
A-sector Kautzy valve tests in SITU
116001005
Measurement of the Sigma+ Magnetic Moment