In an MIT News article playfully titled “No matter the size of a nuclear party, some protons and neutrons will always pair up and dance,” author Jennifer Chu explains that findings on the interactions of protons and neutrons recently published in the journal Nature Physics show that the nucleons may behave like atoms in a gas.
A Massachusetts Institute of Technology–led team simulated the behavior of nucleons in several types of atomic nuclei using supercomputers at Los Alamos National Laboratory and Argonne National Laboratory. The team investigated a range of nuclear interaction models and found that formulas describing a concept known as contact formalism can be generalized to predict how protons and neutrons interact at close range.
Contact formalism predicts that atoms in a gas that are far from one another and atoms that are very close together will interact in different, yet predictable, ways.
The researchers found that when nucleons are less than 1 femtometer—1 quadrillionth of a meter—apart, the particles pair up in a similar way in both small atoms, such as helium (atomic number 2), and denser atoms, such as calcium (atomic number 20). According to Chu, the researchers believe that the behavior “is likely universal for all types of atomic nuclei, such as the much denser, complicated nuclei in radioactive atoms.”