$p_T^Z$, $p_T^W$ measurement in ATLAS

by Fabrice Balli (CEA Saclay), Dr Luca Rottoli (University of Zurich (CH))

Thursday 21 Sept 2023, 11:00 → 13:00 Europe/Zurich

4/2-011 - TH common room (CERN)

The differential spectrum of electroweak gauge bosons, measured via their leptonic decays, is among the most important observables at the LHC. The level of precision reached in the experimental measurements plays a prominent role in the extraction of parton distribution functions as well as in the determination of fundamental SM parameters, such as the strong coupling constant and the W mass. For this reason, an accurate theoretical understanding of transverse momentum observables is paramount to exploit the precise data and perform meticulous tests of the SM. In this talk we discuss recent advancements in the theoretical descriptions of the transverse momentum spectra of electroweak bosons and how they compare to experimental data. We furthermore describe the experimental techniques employed for the reconstruction of the differential spectra, focussing in particular the challenges in the reconstruction of the W transverse momentum. We present recent results by the ATLAS collaboration and we discuss possible strategies to exploit accurate computations of QCD and QED corrections in the context of LHC measurements.

Fabrice Balli is an ATLAS experimental physicist. He did is PhD thesis in CEA Saclay on the top quark mass measurement and jet energy calibration in ATLAS, and moved in 2014 to the University of Manchester as postoctoral research associate. During that time he was appointed co-responsible of the jet energy scale and jet energy resolution (JES/JER) sub-group of ATLAS. In 2015 he obtained a permanent position at CEA Saclay, where he led several analyses on precision electroweak physics, in particular the measurement of W, Z cross-sections, the transverse momentum of the W (pTW) and the W mass using low pileup data. Having being involved in the commissioning of the New Small Wheel electronics in the years 2021-2022, he led in parallel the measurement of pTW for which a preliminary result has been released last Spring. From October 1st, he will be co-responsible of the Jet/ETMiss group in ATLAS.

Luca Rottoli is an SNF Ambizione Fellow in theoretical particle physics at the University of Zürich. Previously, he held a postdoctoral position at the University of Milano Bicocca and he has been a postdoctoral research affiliate at the Lawrence Berkeley National Laboratory. He obtained his PhD at the University of Oxford. His research interests focus on a variety of phenomenological and more formal aspects of QCD, ranging from the precise determination of PDFs to the development of tools for high-order and all-order analytic computations.