Precision measurement of the $\eta\to\pi^+\pi^-\pi^0$ Dalitz plot distribution with the KLOE detector

Anastasi, A.; Babusci, D.; Bencivenni, G.; Berlowski, M.; Bloise, C.; Bossi, F.; Branchini, P.; Budano, A.; Caldeira Balkeståhl, L.; Cao, B.; Ceradini, F.; Ciambrone, P.; Curciarello, F.; Czerwiński, E.; D'Agostini, Giulio; Dané, E.; De Leo, V.; De Lucia, E.; De Santis, A.; De Simone, P.; Di Cicco, A.; Di Domenico, Antonio; Di Salvo, R.; Domenici, D.; D'Uffizi, A.; Fantini, A.; Felici, G.; Fiore, S.; Gajos, A.; Gauzzi, Paolo; Giardina, G.; Giovannella, S.; Graziani, E.; Happacher, F.; Heijkenskjöld, L.; Ikegami Andersson, W.; Johansson, T.; Kamińska, D.; Krzemien, W.; Kupsc, A.; Loffredo, S.; Mandaglio, G.; Martini, M.; Mascolo, M.; Messi, R.; Miscetti, S.; Morello, G.; Moricciani, D.; Moskal, P.; Papenbrock, M.; Passeri, A.; Patera, Vincenzo; Perez Del Rio, E.; Ranieri, A.; Santangelo, P.; Sarra, I.; Schioppa, M.; Silarski, M.; Sirghi, F.; Tortora, L.; Venanzoni, G.; Wiślicki, W.; Wolke, M.

doi:10.1007/JHEP05(2016)019

Using 1.6 fb−1 of e+e− → ϕ → ηγ data collected with the KLOE detector at DAΦNE, the Dalitz plot distribution for the η → π+π−π0 decay is studied with the world’s largest sample of ∼ 4.7 · 106 events. The Dalitz plot density is parametrized as a polynomial expansion up to cubic terms in the normalized dimensionless variables X and Y . The experiment is sensitive to all charge conjugation conserving terms of the expansion, including a gX2Y term. The statistical uncertainty of all parameters is improved by a factor two with respect to earlier measurements.

Precision measurement of the $\eta\to\pi^+\pi^-\pi^0$ Dalitz plot distribution with the KLOE detector / Anastasi, A., Babusci, D., Bencivenni, G., Berlowski, M., Bloise, C., Bossi, F., Branchini, P., Budano, A., Caldeira Balkeståhl, L., Cao, B., Ceradini, F., Ciambrone, P., Curciarello, F., Czerwiński, E., D'Agostini, G., Dané, E., De Leo, V., De Lucia, E., De Santis, A., De Simone, P., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1126-6708. - STAMPA. - 05:(2016). [10.1007/JHEP05(2016)019]