The nonstrange dibaryon and hidden-color effect in a chiral quark model L. R. Dai, Y. N. Zhang, Y. L. Sun and S. J. Shao Eur. Phys. J. A, 52 9 (2016) 295 Published online: 26 September 2016 DOI: 10.1140/epja/i2016-16295-6