3H/3He ratio as a probe of the nuclear symmetry energy at sub-saturation densities Yongjia Wang, Chenchen Guo, Qingfeng Li and Hongfei Zhang Eur. Phys. J. A, 51 3 (2015) 37 Published online: 26 March 2015 DOI: 10.1140/epja/i2015-15037-8