Neutron Stars and the Universe's mysteries revealed via the Skin of an Atomic Nucleus
In a recent article published in the scientific journal Nature Physics, Chalmers researchers present a breakthrough in the calculation of the atomic nucleus of the heavy and stable element lead.
When a star dies, its violent death can lead to the birth of a Neutron Star. A teaspoon of the several-kilometer neutron star weighs a billion tonnes, making it one of the universe's true heavyweights.
Despite the immense size difference between a microscopic atomic nucleus and a neutron star several kilometers in size, the physics that governs their attributes is essentially the same.
The atomic nucleus of the Isotope lead-208 and a Neutron star are unimaginably different in size, but most of their properties are described by the same physical principles.
It is believed that massive neutron stars colliding in space are able to create precious metals such as Gold and Platinum.
While the properties of these stars still remain a mystery, the answer may be under the skin of one of Earth's smallest building blocks "an atomic nucleus of lead".
It has proven difficult to get the atom's nucleus to reveal the secrets of the strong force that governs the interior of neutron stars.
The common denominator is the strong force that holds the particles "protons and neutrons" together in an atomic nucleus. The same force also prevents a neutron star from collapsing.
Although the strong force is fundamental in the cosmos, yet including it in computer models is difficult. This is especially true for heavy neutron-rich atomic nuclei like lead.
Therefore, scientists have struggled with many unanswered questions in their difficult calculations.
In order to study the atomic nucleus of lead, researchers from the Chalmers University of Technology in Sweden have now developed a new computational model that can provide answers.
Chalmers' new computer model, developed together with colleagues in North America and England, now points the way forward.
It enables high-precision predictions of properties for the isotope lead-208 and its so-called ‘neutron skin’. Isotope lead-208 has 126 neutrons and 82 protons.
According to this new computational model
Heavy atomic nuclei have an excess of neutrons over protons, resulting in the formation of a neutron skin whose thickness is sensitive to nuclear force details.
The 126 neutrons (red) in the atomic nucleus form an outer envelope, which can be described as skin. The thickness of the skin matters. How thick the skin is, is linked to the properties of the strong force.
By predicting the thickness of the neutron skin, scientists can learn more about how the strong force works in both atomic nuclei and neutron stars.
Research leader Christian Forssén, Professor at the Department of Physics at Chalmers says, "we predict that the neutron skin is surprisingly thin, which can provide new insights into the force between the neutrons."
According to him, a breakthrough aspect of their model is its ability to assess theoretical margins of error in addition to providing predictions. This is crucial for achieving scientific progress.
The research was done on some of the world's most powerful supercomputers. Mainly the Swedish Research Council and the European Research Council have funded the Chalmers researchers.Source - Article published in the journal Nature Physics