Jul 4 – 11, 2018
Asia/Seoul timezone

Van der Meer calibration of the CMS luminosity detectors in 2017

Jul 6, 2018, 10:07 AM
105 (COEX, Seoul)


COEX, Seoul

Parallel Accelerator: Physics, Performance, and R&D for Future Facilities Accelerators: Physics, Performance, and R&D for Future Facilities


Dr Moritz Guthoff (Deutsches Elektronen-Synchrotron (DE)) Olena Karacheban (CERN) Paul Lujan (Universita e INFN, Padova (IT)) Chris Palmer (Princeton University (US))


To guarantee smooth and uninterrupted luminosity measurements the CMS experiment is equipped in Run II with three online luminometers: the Pixel Luminosity Telescope (PLT), the Fast Beam Condition Monitor (BCM1F) and the Forward Calorimeter (HF). For the offline luminosity measurement and a cross check of the online detectors the pixel detector is used (Pixel Cluster Counting, PCC). For the calibration of the luminometers once per year a full program of van der Meer (VdM) scans is performed. It consists of series of standard VdM scans and 4 imaging scans. In the standard VdM scans both beams are moving across each other and the transverse size of the beam overlap is defined. Imaging VdM scans are required to disentangle XY correlation. For steering magnet calibrations, under the special beam conditions during the VdM scan, the length scale (LS) calibration is performed. Detailed studies of the systematic effects of beam-beam deflections, orbit drift, LS calibration and unbunched beam correction allow precise luminosity calibration. The methodology of the luminosity calibration and final uncertainty on the integrated luminosity will be presented.

Primary authors

Anton Babaev (National Research Tomsk Polytechnic University (RU)) James Dale Bueghly (Northwestern University (US)) Edgar Carrera Jarrin (Boston University) Anne Dabrowski (CERN) Jonas Daugalas (Vilnius University (LT)) Andres Guillermo Delannoy Sotomayor (University of Tennessee (US)) Thoth Kenneth Gunter (Northwestern University (US)) Dr Moritz Guthoff (Deutsches Elektronen-Synchrotron (DE)) Joseph Heideman (University of Tennessee (US)) Sam Higginbotham (Princeton University (US)) Alexis Kalogeropoulos (Princeton University) Olena Karacheban (CERN) Joscha Knolle (Deutsches Elektronen-Synchrotron (DE)) Andreas Kornmayer (CERN) Mr Georgios Krintiras (Universite Catholique de Louvain (UCL) (BE)) Arkady Lokhovitskiy (University of Canterbury (NZ)) Paul Lujan (Universita e INFN, Padova (IT)) Jingyu Luo (Princeton University (US)) Peter Major (Eotvos Lorand University (HU)) Daniel Marlow (Princeton University (US)) Chris Palmer (Princeton University (US)) Jakob Salfeld-Nebgen (Princeton University (US)) David Stickland (Princeton University (US)) Dr Nicolo Tosi (INFN Bologna, Bologna (IT)) Peter Tsrunchev (University of Sofia (BG)) Oleksii Turkot (DESY) Zhen Xie (Princeton University (US))

Presentation materials