  We investigate the modification of the Higgs signals from vector boson fusion
at the LHC arising from higher-dimensional effective operators involving
quarks, electroweak gauge bosons and the 125-GeV scalar discovered in 2012.
Taking a few of the admissible dimension-6 operators as illustration, we work
within the framework of the Standard Model Effective Field Theory (SMEFT) and
identify kinematic variables that can reflect the presence of such effective
operators. The useful variables turn out to be the geometric mean of the
transverse momenta of the two forward jets produced in VBF and the rapidity
difference between the two forward jets. We identify the shift in event
population caused by the effective operators in the same, spanned by the above
kinematic variables. Minimum values of the Wilson coefficients of the chosen
dimension-6 operators are identified, for which they can be probed at the
$3\sigma$ level in the high luminosity run of the LHC at 14 TeV. Projected
exclusion limits on some of the couplings, obtained from our analysis, can
significantly improve the limits on such couplings derived from electroweak
precision data.
