Tuggle, Joseph M.I present measurements of radiative B meson decays to the final states K<sub>S</sub> &pi;<super>0</super> &gamma; and K &phi; &gamma; based on data collected at the &Upsilon;(4S) resonance with the BaBar detector at the PEP-II e<super>+</super>e<super>&ndash;</super> collider at SLAC. In a data sample of 467 million BBbar pairs, the time-dependent CP asymmetry in B<super>0</super> &rarr; K<sub>S</sub> &pi;<super>0</super> &gamma; decays is measured in two regions of K<sub>S</sub>-&pi;<super>0</super> invariant mass. In the K* region, 0.8 < m(K<sub>S</sub> &pi;<super>0</super>) < 1.0 GeV/c<super>2</super>, we find S<sub>K* &gamma;</sub> = &ndash;0.03 &plusmn; 0.29 &plusmn; 0.03 and C<sub>K* &gamma;</sub> = &ndash;0.14 &plusmn; 0.16 &plusmn; 0.03; in the range 1.1 < m(K<sub>S</sub> &pi;<super>0</super>) < 1.8 GeV/c<super>2</super>, we find S<sub>KS &pi;0 &gamma;</sub> = &ndash;0.78 &plusmn; 0.59 &plusmn; 0.09 and C<sub>KS &pi;0 &gamma;</sub> = &ndash;0.36 &plusmn; 0.33 &plusmn; 0.04. With a sample of 228 million BBbar pairs we measure the branching fraction B(B<super>+</super> &rarr; K<super>+</super> &phi; &gamma;) = (3.5 &plusmn; 0.6 &plusmn; 0.4) &times; 10<super>&ndash;6</super> and set the limit B(B<super>0</super> &rarr; K<super>0</super> &phi; &gamma;) < 2.7 &times; 10<super>&ndash;6</super> at 90% confidence level. The direct CP asymmetry in B<super>+</super> &rarr; K<super>+</super> &phi; &gamma; is found to be A<sub>CP</sub> = (&ndash;26 &plusmn; 14 &plusmn; 5)%. In each case the uncertainties are statistical and systematic, respectively.en-USRadiative B Meson Decay as a Probe of Physics Beyond the Standard Model: Time-Dependent CP Violation in B<super>0</super> &rarr; K<sub>S</sub> &pi;<super>0</super> &gamma; and the B &rarr; &phi; K &gamma; Branching FractionDissertationPhysics, Elementary Particles and High EnergyB MesonElectroweak pengiunRadiative penguinRare decay