Modified two-body potential approach to the peripheral direct capture astrophysical <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mi>a</mml:mi><mml:mo>+</mml:mo><mml:mi>A</mml:mi><mml:mo>→</mml:mo><mml:mi>B</mml:mi><mml:mo>+</mml:mo><mml:mi>γ</mml:mi></mml:math> reaction and asymptotic normalization coefficients