arXiv subjects
Publications and source records attributed to Greg Landsberg.
We evaluate the prospects for detecting a non-standard light Higgs boson with a significant branching ratio to two photons, in Run II of the Fermilab Tevatron. We derive the reach for several channels: $2γ$ inclusive, $2γ+1$ jet and $2γ+2$ jets. We present the expected Run II limits on the branching ratio of $h\toγγ$ as a function of the Higgs mass, for the case of ``bosonic'', as well as ``topcolor'' Higgs bosons.
We present recent results on searches for non-SUSY new physics at the CDF and D0 Collaborations in the 1992-1996 Fermilab Tevatron run. While no compelling evidence for existence of new physics was found, the Tevatron data have excluded a significant region of the theoretically allowed phase space for a variety of non-SUSY extensions of the Standard Model. Tight limits on the existence of the following new phenomena are set: leptoquarks of all three generations, quark-lepton compositeness, 4-th generation quarks, fermiophobic Higgs, technicolor, etc. Prospects of the Tevatron experiments in Run II are discussed.
In the model of Arkani-Hamed, Dimopoulos, and Dvali where gravity is allowed to propagate in the extra dimensions of very large size, virtual graviton exchange between the standard model particles can give rise to signatures that can be tested in collider experiments. We study these effects in dilepton and diphoton production at hadron colliders. Specifically, we examine the double differential cross-section in the invariant mass and scattering angle, which is found to be useful in separating the gravity effects from the standard model. In this work, sensitivity obtained using the double differential cross-section is higher than that in previous studies based on single differential distributions. Assuming no excess of events over the standard model predictions, we obtain the following 95% confidence level lower limits on the effective Planck scale: $0.9-1.5$ TeV in the Tevatron Run I, $1.3-2.5$ TeV in Run IIa, $1.7-3.5$ TeV in Run IIb, and $6.5-12.8$ TeV at the LHC. The range of numbers corresponds to the number of extra dimensions $n=7-2$.
We discuss possibilities of detecting neutral and charged long-lived particles with the upgraded D0 detector in Run II of the Fermilab Tevatron accelerator, using photon pointing, dE/dx, and time-of-flight techniques. Such particles appear in many SM extensions, e.g., Gauge Mediated SUSY. This work has been done in the context of the BTMSSM Working group of the Run II SUSY/Higgs Workshop at Fermilab.