Big Bang Nucleosynthesis Reactions Catalyzed by a Long Lived Negatively Charged Leptonic Particle

An accurate quantum three body calculation is performed for the new type of big bang nucleosynthesis (BBN) reactions that are catalyzed by a hypothetical long lived negatively charged, massive leptonic particle (called X−) such as the supersymmetric (SUSY) particle stau, the scalar partner of the tau lepton. It is known that if the X− particle has a lifetime τX ≳103 s, it can capture a light element previously synthesized in standard BBN and form a Coulombic bound state, for example, (7Be X−) at temperature T9 ≲0.4 (in units of 109 K), (αX−) at T9 ≲ 0.1 and (pX−) at T9 ≲ 0.01. The bound state, an exotic atom, is expected to induce the following reactions in which X− acts as a catalyst: i) α transfer reactions such as (αX−) + d → 6Li + X, ii) radiative capture reactions such as (7Be X−) + p → (8B X−) + γ, iii) three body breakup reactions such as (7Li X−) + p → α + α + X−, iv) charge exchange reactions such as (pX−) + α → (αX−) +p and v) neutron induced reactions such as (8Be X−) + n →9Be + X−. In recent papers it has been claimed that some of these X− catalyzed reactions have significantly large cross sections so that the inclusion of the reactions into the BBN network calculation can markedly change the abundances of some elements, giving not only a solution to the 6Li 7Li problem (the calculated underproduction of 6Li by a factor of ∼1000 and overproduction of 7Li+7Be by a factor of ∼3) but also a constraint on the lifetime and primordial abundance of the elementary particle X−. However, most of these calculations of the reaction cross sections in the literature were performed assuming too naive models or approximations that are unsuitable for these complicated low energy nuclear reactions. We use a high accuracy few body calculation method developed by the authors and provide precise cross sections and rates of these catalyzed BBN reactions for use in the BBN network calculation.