Is it possible to improve(fix) a paper after its acceptance by the conference
Generally, papers presented at conferences include the preliminary results, and the purpose is to receive feedback on your preliminary results and improve them for the final study. If this is the case with your paper, I think you could consider making the improvement after the conference, since you are going to improve the study anyways later on based on the inputs you receive at the conference. However, if you strongly feel that making the change would improve the paper significantly, you can write to the Chairman and explain your concern. If he agrees, you can make the change.