From the lineshape of the $X(3872)$ to its structure
| Autor: | Esposito, Angelo, Maiani, Luciano, Pilloni, Alessandro, Polosa, Antonio D., Riquer, Veronica |
|---|---|
| Rok vydání: | 2021 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.105.L031503 |
| Popis: | From a study of the lineshape of the $X(3872)$, the LHCb collaboration measures a sizeable negative effective range. This cannot be reconciled with a shallow $D\bar{D}^*$ bound state hypothesis. Based on Weinberg's compositeness criterion, together with a theorem by Smorodinsky, it follows that the $X$ has to have a compact hidden charm structure, most likely a tetraquark, interacting with unbound $D\bar{D}^*$ pairs via short-distance color forces. This conclusion is strengthened by the general pattern recently emerging for exotic mesons. Comment: 6 pages. Updated version including the evaluation of the error on the effective range. Discussion and conclusions unchanged. To appear as a Letter in Physical Review D |
| Databáze: | arXiv |
| Externí odkaz: |
|