R2 log R quantum corrections and the inflationary observables

We study a model of inflation with terms quadratic and logarithmic in the Ricci scalar, where the gravitational action is f (R) = R+alpha R-2+beta R-2 In R. These terms are expected to arise from one loop corrections involving matter fields in curved space-time. The spectral index ris and the tensor to scalar ratio yield 4 x 10(-4) less than or similar to r less than or similar to 0.03 and 0.94 less than or similar to n(s) <= 0.99. i.e. r is an order of magnitude bigger or smaller than the original Starobinsky model which predicted r similar to 10(-3). Further enhancement of r gives a scale invariant n(s) similar to 1 or higher. Other inflationary observables are dn(s)/d ln k greater than or similar to 5.2 x 10(-4), mu less than or similar to 2.1 x 10(-8), y less than or similar to 2.6 x 10(-9). Despite the enhancement in r, if the recent BICEP2 measurement stands, this model is disfavoured.