Absolute luminosity measurements are of general interest for colliding-beam
experiments at storage rings. These measurements are necessary to determine the
absolute cross-sections of reaction processes and are valuable to quantify the
performance of the accelerator. LHCb has applied two methods to determine the
absolute scale of its luminosity measurements for proton-proton collisions at
the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van
der Meer scan" method a novel technique has been developed which makes use of
direct imaging of the individual beams using beam-gas and beam-beam
interactions. This beam imaging method is made possible by the high resolution
of the LHCb vertex detector and the close proximity of the detector to the
beams, and allows beam parameters such as positions, angles and widths to be
determined. The results of the two methods have comparable precision and are in
good agreement. Combining the two methods, an overal precision of 3.5% in the
absolute luminosity determination is reached. The techniques used to transport
the absolute luminosity calibration to the full data-taking period are
presented.
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
REGISTER
Did you like this article? 
