@article{aec84c01308648b7a963aaccf4f19526,
title = "Importance of d-wave contributions in the charge symmetry breaking reaction dd→4Heπ0",
abstract = "This letter reports a first quantitative analysis of the contribution of higher partial waves in the charge symmetry breaking reaction dd→4Heπ0 using the WASA-at-COSY detector setup at an excess energy of Q=60MeV. The determined differential cross section can be parametrized as dσ/dΩ=a+bcos2θ⁎, where θ⁎ is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a=(1.55±0.46(stat)+0.32 −0.8(syst))pb/sr and b=(13.1±2.1(stat)−2.7 +1.0(syst))pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the Δ isobar to the dd→4Heπ0 reaction and is, therefore, crucial for a quantitative understanding of quark mass effects in nuclear production reactions.",
keywords = "Charge symmetry breaking, Deuteron–deuteron interactions, Pion production, NEAR-THRESHOLD, Deuteron deuteron interactions, MESON PRODUCTION, QUARK MASSES, COSY, COLLISIONS",
author = "{The WASA-at-COSY Collaboration} and P. Adlarson and W. Augustyniak and W. Bardan and M. Bashkanov and Bergmann, {F. S.} and M. Ber{\l}owski and A. Bondar and M. B{\"u}scher and H. Cal{\'e}n and I. Ciepa{\l} and H. Clement and E. Czerwi{\'n}ski and K. Demmich and R. Engels and A. Erven and W. Erven and W. Eyrich and P. Fedorets and K. F{\"o}hl and K. Fransson and F. Goldenbaum and A. Goswami and K. Grigoryev and Gullstr{\"o}m, {C. O.} and C. Hanhart and L. Heijkenskj{\"o}ld and V. Hejny and N. H{\"u}sken and L. Jarczyk and T. Johansson and B. Kamys and G. Kemmerling and G. Khatri and A. Khoukaz and O. Khreptak and Kirillov, {D. A.} and S. Kistryn and H. Kleines and B. K{\l}os and W. Krzemie{\'n} and P. Kulessa and A. Kup{\'s}{\'c} and A. Kuzmin and K. Lalwani and D. Lersch and B. Lorentz and A. Magiera and R. Maier and P. Marciniewski and B. Shwartz",
year = "2018",
month = jun,
day = "10",
doi = "10.1016/j.physletb.2018.04.037",
language = "English",
volume = "781",
pages = "645--650",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",
}