@article{cc450bb54e8c428e9e22ae58483d48d7,

title = "Probing the core of the strong nuclear interaction",

abstract = "The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of quantum chromodynamics. However, as these equations cannot be solved directly, nuclear interactions are described using simplified models, which are well constrained at typical inter-nucleon distances1–5 but not at shorter distances. This limits our ability to describe high-density nuclear matter such as that in the cores of neutron stars6. Here we use high-energy electron scattering measurements that isolate nucleon pairs in short-distance, high-momentum configurations7–9, accessing a kinematical regime that has not been previously explored by experiments, corresponding to relative momenta between the pair above 400 megaelectronvolts per c (c, speed of light in vacuum). As the relative momentum between two nucleons increases and their separation thereby decreases, we observe a transition from a spin-dependent tensor force to a predominantly spin-independent scalar force. These results demonstrate the usefulness of using such measurements to study the nuclear interaction at short distances and also support the use of point-like nucleon models with two- and three-body effective interactions to describe nuclear systems up to densities several times higher than the central density of the nucleus.",

author = "The CLAS Collaboration and A. Schmidt and Pybus, {J. R.} and R. Weiss and Segarra, {E. P.} and A. Hrnjic and A. Denniston and O. Hen and E. Piasetzky and Weinstein, {L. B.} and N. Barnea and M. Strikman and A. Larionov and D. Higinbotham and A. Schmidt and Pybus, {J. R.} and R. Weiss and Segarra, {E. P.} and A. Hrnjic and A. Denniston and O. Hen and E. Piasetzky and Weinstein, {L. B.} and N. Barnea and M. Strikman and A. Larionov and D. Higinbotham and S. Adhikari and M. Amaryan and G. Angelini and G. Asryan and H. Atac and H. Avakian and Gayoso, {C. Ayerbe} and L. Baashen and L. Barion and M. Bashkanov and M. Battaglieri and A. Beck and I. Bedlinskiy and F. Benmokhtar and A. Bianconi and Biselli, {A. S.} and F. Boss{\`u} and S. Boiarinov and M. Brahim and Briscoe, {W. J.} and W. Brooks and Burkert, {V. D.} and F. Cao and M. Dugger",

note = "Funding Information: Acknowledgements We acknowledge the efforts of the staff of the Accelerator and Physics Divisions at Jefferson Lab that made this experiment possible. The analysis presented here was carried out as part of the Jefferson Lab Hall B data-mining project supported by the US Department of Energy (DOE). The research was also supported by the National Science Foundation, the Israel Science Foundation, the Pazi Foundation, the Chilean Comisi{\'o}n Nacional de Investigaci{\'o}n Cient{\'i}fica y Tecnol{\'o}gica, the French Centre National de la Recherche Scientifique and Commissariat a l'Energie Atomique, the French–American Cultural Exchange, the Italian Istituto Nazionale di Fisica Nucleare, the National Research Foundation of Korea, and the UK Science and Technology Facilities Council. Jefferson Science Associates operates the Thomas Jefferson National Accelerator Facility for the DOE, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.",

year = "2020",

month = feb,

day = "27",

doi = "10.1038/s41586-020-2021-6",

language = "English (US)",

volume = "578",

pages = "540--544",

journal = "Nature",

issn = "0028-0836",

publisher = "Nature Publishing Group",

number = "7796",

}