alpha particle mass

sub-atomic physics. Symbol m_α. 6.644 656 5(11) × 10^-27 kg = 7 294.299 536 3(32) m_e with relative standard uncertainties 1.7 × 10^-7 and 4.4 × 10^-10.
[Mohr P. J., Taylor B. N. CODATA Recommended Values of the Fundamental Physical Constants: 2002 (to be published)]
[Mohr P. J., Taylor B. N. Rev. Mod. Phys. Vol. 72:351-495 (2000)]
[Mohr P. Phys. Today Vol. 53:7, 11-16 (2000)]
[For latest recommended values, see http://physics.nist.gov/cuu/Constants/index.html]