Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Performance of the LHCb Vertex Detector Alignment Algorithm determined
  with Beam Test Data   LHCb is the dedicated heavy flavour experiment at the Large Hadron Collider
at CERN. The partially assembled silicon vertex locator (VELO) of the LHCb
experiment has been tested in a beam test. The data from this beam test have
been used to determine the performance of the VELO alignment algorithm. The
relative alignment of the two silicon sensors in a module and the relative
alignment of the modules has been extracted. This alignment is shown to be
accurate at a level of approximately 2 micron and 0.1 mrad for translations and
rotations, respectively in the plane of the sensors. A single hit precision at
normal track incidence of about 10 micron is obtained for the sensors. The
alignment of the system is shown to be stable at better than the 10 micron
level under air to vacuum pressure changes and mechanical movements of the
assembled system.

17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg