Measurement of the Inclusive Jet Cross Section with the ATLAS Detector at the Large Hadron Collider
This thesis presents the measurement of the inclusive jet cross section using data collected in 2010 by the ATLAS detector, with a particular focus on the reconstruction and calibration techniques used for jets in this measurement and on the estimate of the systematic uncertainty on their energy scale. The inclusive jet cross section measurement is used as input to fits of parton distribution functions. Although the PDF analysis in this thesis is preliminary and its main purpose is to serve as
... ose is to serve as a proof of principle for future studies, improvements in the knowledge of the gluon density are observed thanks to the inclusion of ATLAS data. iv v Acknowledgements There are many people to whom I am indebted. First of these is my supervisor, Amanda Cooper-Sarkar. She has been incredibly supportive when I have needed it, and at the same time has given me the freedom to pursue work of my own choosing. Much of the work in this thesis was influenced by Tancredi Carli, whose encouragement, guidance and approachability during my time at CERN made much of this thesis write itself. Thanks to Cigdem Issever for always helping me see the big picture, to the other Oxford group members (Tony Weidberg, Hugo Beauchemin and Todd Huffmann in particular) for the advice on both physics and the practical side of things and to Alan Barr for being the perfect College Advisor. I am grateful to the Oxford Particle Physics secretaries for turning bureaucracy into something easy that could be handled with a smile. Thanks also to Peter Loch, for giving me chances to take over both the JetPerformance code and his kitchen, even though he's a master of both. My D. Phil. course in Oxford was supported by the concrete help of a number of Foundations: the Rotary Club (Clubs of Feltre (BL) and Pinner, with special thanks to Ian and Judy Shave for always being more than wonderful counsellors), the Blanceflor, Scatcherd and Charterhouse Foundations, the Stapley Trust, the British Foundation of Women Graduates and the Fondazione Della Riccia. Thanks to Dag, Toshi, Michael and the other JetEtMiss activists for making me feel part of a strong team where deadlines were challenging but still fun. In particular, thanks to Pier-Olivier: without suggestions (and live office-playing) of an excellent soundtrack, deriving a JES uncertainty wouldn't have been so epic and HAppy. Dag (again), Paolo, Bogdan, Pavel, Shima, Mario, Pavel, Eric and all the other inclusive jet/dijet cross section analysers at CERN deserve special thanks for answering all my questions at all times and for not complaining about the burned cakes I sometimes brought to meetings. Thanks to Frederik and Yumi for teaching me things about jets, (recursive) limit setting and proper screeching, and to Heidrun for the patience whenever she had to listen to all of these. I am also indebted to Sing and Teresa for overseas delivery of ramen, Canadian coke and advice when needed. Thanks to the Oxford Physics peeps: Sam+James=JAM, Dan, Alex, Phil, theBODDY and the younglings for filling the days in the department with banter. I would also like to thank Steven, Mike, Francoise, Mel, Robin, the ducks that sift primes in the Cherwell and the lesser waterchickens since they all contributed to make Oxford sunny regardless of British weather. Thanks to the LTA for the tablesnakes, coffees, ski trips and nights out. Special thanks to the LTA girls for keeping up the tradition of girly nights. Thanks to the colleghe, Market, Chiara+Gae, the Toni, the Valery, Laura, Nadia, Olivia and Dirk for all the skype/email/live support.