The UVES Large Program for Testing Fundamental Physics II: Constraints
  on a Change in {\mu} Towards Quasar HE 0027-1836
  We present an accurate analysis of the H2 absorption lines from the zabs ~
2.4018 damped Ly{\alpha} system towards HE 0027-1836 observed with the Very
Large Telescope Ultraviolet and Visual Echelle Spectrograph (VLT/UVES) as a
part of the European Southern Observatory Large Programme "The UVES large
programme for testing fundamental physics" to constrain the variation of
proton-to-electron mass ratio, {\mu} = mp/me. We perform cross-correlation
analysis between 19 individual exposures taken over three years and the
combined spectrum to check the wavelength calibration stability. We notice the
presence of a possible wavelength dependent velocity drift especially in the
data taken in 2012. We use available asteroids spectra taken with UVES close to
our observations to confirm and quantify this effect. We consider single and
two component Voigt profiles to model the observed H2 absorption profiles. We
use both linear regression analysis and Voigt profile fitting where
{\Delta}{\mu}/{\mu} is explicitly considered as an additional fitting
parameter. The two component model is marginally favored by the statistical
indicators and we get {\Delta}{\mu}/{\mu} = (-2.5 +/- 8.1(stat) +/- 6.2(sys))
ppm. When we apply the correction to the wavelength dependent velocity drift we
find {\Delta}{\mu}/{\mu} = (-7.6 +/- 8.1(stat) +/- 6.3(sys)) ppm. It will be
important to check the extent to which the velocity drift we notice in this
study is present in UVES data used for previous {\Delta}{\mu}/{\mu}
measurements.
