  We use reduced fidelity approach to characterize quantum phase transitions in
the one-dimensional spin-1/2 dimerized Heisenberg chain in the
antiferromagnetic case. The reduced fidelity susceptibilities between two
nearest-neighboring spin pairs are considered. We find that they are directly
related to the square of the second derivative of the ground-state energy. This
enables us to conclude that the former might be a more effective indicator of
the second-order quantum phase transitions than the latter. Two further
exemplifications are given to confirm the conclusion is available for a broad
class of systems with SU(2) and translation symmetries. Moreover, a general
connection between reduced fidelity susceptibility and quantum phase
transitions is illustrated.
