U(1)B−LU(1)B−L extra-natural inflation with Standard Model on a brane

The interrelation between inflationary cosmology and new physics beyond the Standard Model (SM) is studied in a U(1)B−LU(1)B−L extension of the SM embedded in a (4+14+1)-dimensional spacetime. In the scenario we study, the inflaton arises from the Wilson loop of the U(1)B−LU(1)B−L gauge group winding an extra-dimensional cycle. Particular attention is paid to the coupling between the inflaton and SM particles that are confined on a brane localized in the extra dimension. We find that the inflaton decay channels are rather restricted in this scenario and the resulting reheating temperature is relatively low.