JET X SECTION · Measurement of the inclusive jet cross section

Measurement of the inclusive jet cross section

The goal of the project is the measurement of the inclusive jet cross section with the ATLAS detector using proton-proton collisions at a centre of mass energy of sqrt(s) = 7 TeV provided by the Large Hadron Collider. The researcher focused in the 2011 dataset which has 100 times the amount of data of the first measurement done with the 2010 data. This measurement used jets with transverse momenta in the TeV regime and thus tests the shortest space-time distances in the structure of the proton accessible today. As an additional benefit, a small uncertainty in the jet energy measurement was determined exploiting the balance of the transverse momenta of a jet and a well measured reference object. This precise calibration translates in a much more precise measurement of the inclusive jet cross section. Also, the theoretical predictions had an important improvement with respect to previous measurements. For the first time, an energy regime is explored where the electroweak corrections play a non-negligible role in the Standard Model prediction. These electroweak corrections have been included in the theoretical prediction. These two factors: better jet energy measurement and more precise theoretical predictions - through the inclusion of the electroweak corrections - makes a more significant data / theory comparison compared with previous measurements. However, the 2011 data taking period had unprecedented levels in the number of additional proton-proton interactions produced in the same bunch crossing where the hard scattering was produced (pile up). Understanding the impact of pile up in the measurement was one of the most challenging points of the project. In the attachment 'Jet X achievement description.pdf', the most relevant features of the measurement are described, emphasising the personal role of the researcher in each of them.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз