/ 99 06 20 8 v 1 1 J un 1 99 9 New physics in tt spin correlations at the Tevatron

X iv : h ep - p h / 99 06 20 8 v 2 3 J un 1 99 9 New physics in tt spin correlations at the Tevatron

We show that the angular distributions of leptons or jets due to tt spin correlations allow a determination of the top chromomagnetic moment κ with an accuracy of order 0.1. The method is quite insensitive to background, event reconstruction, and other experimental uncertainties. The total event number is important, so we suggest the inclusion of all-hadronic events.

X iv : h ep - p h / 99 12 28 1 v 1 9 D ec 1 99 9 A systematic analysis of new physics effects in spin correlations in qq →

I show that there are eight new physics operators that contribute to top pair production and subsequent decay in interference with the leading SM process at the Tevatron and estimate their expected statistical inaccuracies. All fully differential cross sections are calculated in the 6-particle phase space. The observation of angular correlations dramatically improves the accuracy of the extract...

/ 99 06 28 6 v 1 8 J un 1 99 9 B → X s l + l − decays in supersymmetry

ar X iv : h ep - p h / 99 06 23 9 v 1 3 J un 1 99 9 Ruling out a higher spin field solution to the cosmological constant problem

We consider the modification of Newton's gravity law in Dolgov's higher spin models [1, 2] designed to compensate the cosmological constant. We find that the effective Planck mass is unacceptably large in these models. We also point out that the properties of gravitational waves are entirely different in these models as compared to general relativity.

ar X iv : h ep - t h / 99 06 02 9 v 1 3 J un 1 99 9