Disformal transformations and the motion of a particle in semi-classical gravity Sandip Chowdhury, Kunal Pal, Kuntal Pal and Tapobrata Sarkar Eur. Phys. J. C, 81 10 (2021) 946 Published online: 25 October 2021 DOI: 10.1140/epjc/s10052-021-09751-z