Search results for "Global fitting"
showing 2 items of 2 documents
Z physics constraints on vector leptoquarks
1996
We analyze the constraints on vector leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the oblique and non-universal contributions of the most general effective Lagrangian for vector leptoquarks, which exhibits the $SU(2)_L \times U(1)_Y$ gauge invariance. We show that the $Z$ physics leads to stronger bounds on second and third generation vectors leptoquarks than the ones obtained from low energy and the current collider experiments.
Cross section measurements of high-p(T) dilepton final-state processes using a global fitting method
2008
We present a new method for studying high-$p_T$ dilepton events ($e^{\pm}e^{\mp}$, $\mu^{\pm}\mu^{\mp}$, $e^{\pm}\mu^{\mp}$) and simultaneously extracting the production cross sections of $p\bar{p} \to t\bar{t}$, $p\bar{p} \to W^+W^-$, and $p\bar{p} \to \ztt$ at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV. We perform a likelihood fit to the dilepton data in a parameter space defined by the missing transverse energy and the number of jets in the event. Our results, which use $360 {\rm pb^{-1}}$ of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are $\sigma(t\bar{t}) = 8.5_{-2.2}^{+2.7}$ pb, $\sigma(W^+W^-) = 16.3^{+5.2}_{-4.4}$ pb, and $\sigma(\ztt) =291^{+50}_…