We study the three-dimensional quantum Ising spin glass in a transvers
e magnetic field following the evolution of the bond probability distr
ibution under renormalization-group transformations. The phase diagram
(critical temperature T(c) vs transverse field GAMMA) we obtain shows
a finite slope near T = 0, in contrast with the infinite slope for th
e pure case. Our results compare very well with the experimental data
recently obtained for the dipolar Ising spin glass LiHo0.167Y0.833F4,
in a transverse field. This indicates that this system is more appropr
iately described by a model with short-range interactions than by an e
quivalent Sherrington-Kirkpatrick model in a transverse field.