Evidence of forward–backward correlation of pions in ultra-relativistic ring- and jet-like events in interactions at A GeVAzharuddin Ahmed, Nirpat Subba, Shreya Bhattacharjee, Abdel Nasser Tawfik and Prabir Kr. HaldarEur. Phys. J. A, 57 12 (2021) 322DOI: https://doi.org/10.1140/epja/s10050-021-00635-0