Observation of Single Top Quarks at DZero

par Dr Dugan O'Neil (IRFU (CEA) and Simon Fraser University (Canada))

vendredi 25 sept. 2009, 14:00 → 15:00 Europe/Paris

Auditorium M. Vivargent (LAPP)

The top quark, the heaviest known elementary particle, was discovered via pair production at the Tevatron in 1995. While pair production occurs via the strong interaction, it should also be possible to create top quarks singly via the electroweak interaction. There are many reasons to look for this process: a simple measurement of its cross section gives a direct measurement of the CKM element Vtb, measuring the various production modes independently is a sensitive probe of new physics, it is a source of highly polarized top quarks, and its experimental signature is very similar to that of several other interesting processes (eg. light Higgs). These factors have motivated an intense search for single top quark production over the last decade. However, observing this process has proved to be very challenging due to enormous backgrounds. Finally, in early 2009 the D0 and CDF collaborations announced observation of the single top quark production process. This seminar will present the D0 single top observation analysis as well as some of the new measurements which have arisen from it.

Slides oneil_LAPP25092009.pdf