The “Strong CP Problem” is a term used by scientists to describe one of the most well-known physics mysteries of the present. Coming from the baffling peculiarity that neutrons don’t collaborate with electric fields in spite of being comprised of quarks — more modest, principal particles that convey electric charges — the Solid CP Issue places into question the Standard Model of material science, or the arrangement of speculations researchers have been utilizing to make sense of the laws of nature for quite a long time.
A new method for looking for axions, hypothetical particles that could help solve this mystery, has been discovered by a group of theoretical physicists from the University of Minnesota, Twin Cities. The new strategy developed by the physicists opens up previously untapped opportunities for detecting axions in particle collider experiments by collaborating with experimental researchers at the Fermilab National Accelerator Laboratory.
As per the editor’s suggestion, the researchers’ paper appears in Physical Review Letters.
Zhen Liu, co-author of the paper and assistant professor in the University of Minnesota School of Physics and Astronomy, stated, “As particle physicists, we’re trying to develop our best understanding of nature.” Through established theoretical frameworks, scientists have found elementary particles with remarkable success over the past century. Along these lines, it’s very astounding why neutrons don’t couple to electric fields on the grounds that, in our known hypothesis, we would anticipate that they should. If the axion is found, it will significantly advance our fundamental understanding of nature’s structure.”
Collider experiments are one of the primary methods for studying subatomic particles and possibly discovering new ones. Scientists basically cause beams of particles to collide, and when they do, the energy they give off causes other particles to pass through a detector, and scientists can look at their properties.
The proposed method by Liu and his team involves measuring the “decay” product of the hypothetical axion into two muons, which are known particles that are basically the heavier version of the electron. This product is what happens when an unstable heavy particle transforms into multiple lighter particles. The researchers believe they can locate the axion and demonstrate its existence by reconstructing such decays backward from the detector’s muon tracks.
Raymond Co, co-author of the paper and postdoctoral researcher at the William Fine Theoretical Physics Institute and the University of Minnesota School of Physics and Astronomy, stated, “With this research, we’re expanding ways we can search for the axion particle.” Axion decay into muons has never been used to locate the axion particle in neutrino or collider experiments. This study paves the way for future endeavors in our field by providing new opportunities.”
The theoretical aspect of the study is led by Liu and coworkers, as well as Kun-Feng Lyu, a postdoctoral researcher in physics and astronomy at the University of Minnesota, and Soubhik Kumar, a postdoctoral researcher at the University of California, Berkeley. They are a part of the ArgoNeuT collaboration, which brings together experimentalists and theorists from all over the country to conduct experiments at Fermilab to investigate particles.
In this paper, the theoretical team led by the University of Minnesota collaborated with the experimental researchers to search for axions using their new approach and existing ArgoNeuT experiment data. In the future, the researchers intend to apply their theoretical calculations of the axion production rate to the results of the experiments.
More information: R. Acciarri et al, First Constraints on Heavy QCD Axions with a Liquid Argon Time Projection Chamber Using the ArgoNeuT Experiment, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.221802
