Strong-field Breit-Wheeler pair production with bremsstrahlung <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> rays in the perturbative-to-nonperturbative-transition regime

Photoproduction of electron-positron pairs by bremsstrahlung gamma-rays propagating through a high-intensity optical laser wave is studied. By calculating total pair production yields as well energy and angular distributions the produced particles for range intensities, we analyze influence that broad frequency spectrum exerts on properties process in transition region between perturbative non-perturbative interaction regimes. In particular, demonstrate continuous shifting mainly contributing interval frequencies during course indicate characteristic signatures laser-dressed particle mass.