The strangeness production ratios [bar wedge]/∧ and [bar wedge]/K0S are measured by the LHCb detector
from 0.3 nb-1 of proton-proton collisions delivered by the Large Hadron Collider (LHC)
at CERN with centre-of-mass energy √s = 0.9TeV and 1.8 nb-1 at √s = 7TeV. Both
ratios are presented as a function of transverse momentum, pT, and rapidity, y, in the
ranges 0.15 < pT < 2.50 GeV/c and 2.0 < y < 4.5. The ratios measured at the two energies
are in good agreement in an overlapping region of rapidity loss, Δ y = ybeam - y, and are
consistent with previous measurements.
A review of the Standard Model is presented with emphasis on the diffculties in its
application for predictions of physics at the LHC. Phenomenological models are introduced
as the current state of the art for such predictions. Accurate models are required as an
essential benchmark for future discoveries of physics beyond the Standard Model. LHCb's
results represent a powerful test for these models in the soft QCD regime for processes
including hadronisation. The ratio [bar wedge]/∧, measuring the transport of baryon number from
the collision into the detector, is smaller in data than predicted, particularly at high
rapidity. The ratio [bar wedge]/K0
S, measuring the baryon-to-meson suppression in strange quark
hadronisation, is significantly larger than expected.
The LHCb experiment is introduced, with particular focus on its Ring Imaging
Cherenkov (RICH) detectors. The development and successful implementation of a
method to align those RICH detectors is presented, using proton-proton collision data
from the early running period of the Large Hadron Collider, which began in November
2009. The performance of the RICH detectors is investigated with preliminary analysis
of the Cherenkov photon yield. The RICH mirror positions are monitored using an
automated software control system, which has been running successfully since October
2008
