# Multiplicity Smearing + ### The original concept: > Let me follow the original one first, where they try to smear the gen lvl multiplicity to the reco lvl distribution. 1. Given a certain response matrix, will have the gen lvl mult ($x$) smear to the corresponded reco lvl distribution ($N(y)|_{x}$) ![](https://i.imgur.com/qRQ9iDB.png) 2. So the concept is actually like a convolutional operation: $\delta(x) \to f(y)|_{x}$ ($f(y)|_{x}$: normalized $N(y)|_{x}$), for instance: for $N_{trk}^{gen}=8$, after the operation, will become a smeared distribution ![](https://i.imgur.com/CQzaeCj.png) 3. This can make the smeared gen ntrk distribution look like reco's: ![](https://i.imgur.com/ZUHm9Kh.png) 4. This will not ensure the event-to-event matching btw reco, gen mult, since when doing the smearing as point 2 suggests, it is a random-sampling process. ![](https://i.imgur.com/1vUA7PE.png) + ### Conclusion: It seems to me that this is an operation only applicable on gen level, where we do want smeared/randomized the gen distribution + ### Detailed results: https://drive.google.com/drive/folders/1pOr61WhGcglmqP3o5HyS1sCPbaoezMpk?usp=sharing