Adeva Andany, BernardoAfanasyev, L.Benayoun, MauriceBenelli, AngelaBerka, Z.Brekhovskikh, V.Caragheorgheopol, G.Čechák, ThomasChiba, MasamiChliapnikov, P. V.Ciocarlan, C.Constantinescu, SerbanCostantini, SilviaCurceanu (Petrascu), C.Doskarova, P.Dreossi, DiegoDrijard, DanielDudarev, A.Ferro-Luzzi, MassiFungueiriño Pazos, J. L.Gallas Torreira, María MercedesGómez Rodríguez, FaustinoLópez Aguera, María de los ÁngelesNúñez Pardo, T.Pazos, AntonioPló Casasús, MáximoMolina Rodriguez, JuanRodríguez Fernández, A.Saborido Silva, Juan JoséSantamarina Ríos, CibránTobar Vidal, María JoséVázquez Doce, OtónZrelov, Petr V.2026-01-122026-01-122011-09-03B. Adeva, L. Afanasyev, M. Benayoun, A. Benelli, Z. Berka, V. Brekhovskikh, G. Caragheorgheopol, T. Cechak, M. Chiba, P.V. Chliapnikov, C. Ciocarlan, S. Constantinescu, S. Costantini, C. Curceanu (Petrascu), P. Doskarova, D. Dreossi, D. Drijard, A. Dudarev, M. Ferro-Luzzi, J.L. Fungueiriño Pazos, M. Gallas Torreira, J. Gerndt, P. Gianotti, D. Goldin, F. Gomez, A. Gorin, O. Gorchakov, C. Guaraldo, M. Gugiu, M. Hansroul, Z. Hons, R. Hosek, M. Iliescu, V. Karpukhin, J. Kluson, M. Kobayashi, P. Kokkas, V. Komarov, V. Kruglov, L. Kruglova, A. Kulikov, A. Kuptsov, K.I. Kuroda, A. Lamberto, A. Lanaro, V. Lapshin, R. Lednicky, P. Leruste, P. Levi Sandri, A. Lopez Aguera, V. Lucherini, T. Maki, I. Manuilov, J. Marin, J.L. Narjoux, L. Nemenov, M. Nikitin, T. Nunez Pardo, K. Okada, V. Olchevskii, A. Pazos, M. Pentia, A. Penzo, J.M. Perreau, M. Plo, T. Ponta, G.F. Rappazzo, A. Riazantsev, J.M. Rodriguez, A. Rodriguez Fernandez, A. Romero Vidal, V.M. Ronjin, V. Rykalin, J. Saborido, C. Santamarina, J. Schacher, C. Schuetz, A. Sidorov, J. Smolik, F. Takeutchi, A. Tarasov, L. Tauscher, M.J. Tobar, T. Trojek, S. Trusov, V. Utkin, O. Vázquez Doce, S. Vlachos, O. Voskresenskaya, T. Vrba, C. Willmott, V. Yazkov, Y. Yoshimura, M. Zhabitsky, P. Zrelov, Determination of ππ scattering lengths from measurement of π+π− atom lifetime, Physics Letters B, Volume 704, Issues 1–2, 2011, Pages 24-29, ISSN 0370-2693, https://doi.org/10.1016/j.physletb.2011.08.074https://hdl.handle.net/10347/45014The DIRAC experiment at CERN has achieved a sizeable production of π π atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave ππ scattering length difference |a0−a2| = (0.2533+0.0080−0.0078|stat+0.0078−0.0073|syst)M_pi−^{1} has been attained, providing an important test of Chiral Perturbation Theoryeng© 2011 Elsevier B.V. This is an open access article distributed under the terms of the Creative Commons CC-BY licenseAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/DIRAC experimentElementary atomPionium atomPion scatteringjournal article10.1016/j.physletb.2011.08.0741873-2445open access