In nucleosynthesis three possible paths are known to bridge the mass gaps at A = 5 and A = 8 .
The primary path producing the bulk of the carbon in our Universe proceeds via the triple-alpha process ^ { 4 } He ( 2 \alpha , \gamma ) ^ { 12 } C. This process takes place in helium-burning of red giant stars .
We show that outside a narrow window of about 0.5 % of the strength or range of the strong force , the stellar production of carbon or oxygen through the triple-alpha process is reduced by factors of 30 to 1000 .
Outside this small window the creation of carbon or oxygen and therefore also carbon-based life in the universe is strongly disfavored .
The anthropically allowed strengths of the strong force also give severe constraints for the sum of the light quark masses as well as the Higgs vacuum expectation value and mass parameter at the 1 % level .