Crouching Sigma, Hidden Scalar in $γγ\toπ^0π^0$
| dc.creator | Pennington, M. R. | |
| dc.date | 2006-04-25 | |
| dc.date.accessioned | 2026-07-07T07:09:59Z | |
| dc.date.available | 2026-07-07T07:09:59Z | |
| dc.description | There has long been speculation about the nature of the $σ$-resonance. For three decades Jaffe has argued for a tetraquark composition, while others have claimed it is largely a glueball. A key pointer to its nature is its coupling to two photons. Consequently, there have been recent proposals to observe this important scalar hiding in $γγ\toπ^0π^0$. We show here that the $σ$ is already crouching in this cross-section exactly as measured twenty years ago. What is new is that precise knowledge of the position of the $σ$-pole, provided by the analysis of the Roy equations, now allows its two photon coupling to be accurately fixed. Its two photon width is found to be $(4.1 \pm 0.3)$ keV, a value far too large for a gluonic, or even a tetraquark, state. | |
| dc.description | 10 pages, 4 figures | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0604212 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0604212 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/111285 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Crouching Sigma, Hidden Scalar in $γγ\toπ^0π^0$ | |
| dc.type | text |