Precision Luminosity of LHC Proton-Proton Collisions at 13 TeV Using Hit-Counting with TPX Pixel Devices

Andre Sopczak; Babar Ali; Thanawat Asawatavonvanich; Jakub Begera; Benedikt Bergmann; Thomas Billoud; Petr Burian; Ivan Caicedo; Davide Caforio; Erik Heijne; Josef Janecek; Claude Leroy; Petr Manek; Kazuya Mochizuki; Yesid Mora; Josef Pacik; Costa Papadatos; Michal Platkevic; Stepan Polansky; Stanislav Pospisil; Michal Suk; Zdenek Svoboda

doi:10.1109/tns.2017.2664664

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arXiv · 1702.00711

Precision Luminosity of LHC Proton-Proton Collisions at 13 TeV Using Hit-Counting with TPX Pixel Devices

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Abstract

A network of Timepix (TPX) devices installed in the ATLAS cavern measures the LHC luminosity as a function of time as a stand-alone system. The data were recorded from 13 TeV proton-proton collisions in 2015. Using two TPX devices, the number of hits created by particles passing the pixel matrices was counted. A van der Meer scan of the LHC beams was analysed using bunch-integrated luminosity averages over the different bunch profiles for an approximate absolute luminosity normalization. It is demonstrated that the TPX network has the capability to measure the reduction of LHC luminosity with precision. Comparative studies were performed among four sensors (two sensors in each TPX device) and the relative short-term precision of the luminosity measurement was determined to be 0.1% for 10 s time intervals. The internal long-term time stability of the measurements was below 0.5% for the data-taking period.

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Andre Sopczak, Babar Ali, Thanawat Asawatavonvanich, Jakub Begera, Benedikt Bergmann, Thomas Billoud, Petr Burian, Ivan Caicedo, Davide Caforio, Erik Heijne, Josef Janecek, Claude Leroy, Petr Manek, Kazuya Mochizuki, Yesid Mora, Josef Pacik, Costa Papadatos, Michal Platkevic, Stepan Polansky, Stanislav Pospisil, Michal Suk, Zdenek Svoboda. 2017-02-02. Precision Luminosity of LHC Proton-Proton Collisions at 13 TeV Using Hit-Counting with TPX Pixel Devices. https://doi.org/10.1109/tns.2017.2664664

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