Big Bang's 'lithium mystery' remains a mystery
Scientists have revealed that astrophysics are still clueless about the quantities of lithium predicted to have resulted from the Big Bang which were not found to be actually present in stars, known as the "lithium problem".
The research has been confirmed for the first time in experiments conducted at the underground laboratory in the Gran Sasso mountain in Italy that calculations are correct.
Lithium, aside from hydrogen and helium, is one of the three elements that are created before the first stars form. These three elements were - according to the theory - already created early on, through what is known as "primordial nucleosynthesis." That means that when the universe was only a few minutes old, neutrons and protons merged to form the nuclei of the these elements. At the Laboratory for Underground Nuclear Astrophysics (LUNA), the nucleosynthesis of lithium has now been reproduced by an international team of scientists.
In the Italian underground laboratory, the scientists fired helium nuclei at heavy hydrogen (known as deuterium) in order to reach energies similar to those just after the Big Bang. The idea was to measure how much lithium forms under similar conditions to those during the early stages of the universe. The result of the experiment: the data confirmed the theoretical predictions, which are incompatible with the observed lithium concentrations found in the universe.
Daniel Bemmerer said that for the first time, they could actually study the lithium-6 production in one part of the Big Bang energy range with their experiment.
Lithium-6 (three neutrons, three protons) is one of the element's two stable isotopes. The formation of lithium-7, which possesses an additional neutron, was studied in 2006 by Bemmerer at LUNA.
The study was published in Physical Review Letters.
(Posted on 28-08-2014)