Thursday , February 25 2021

The investigation of atomic parity violation reaches a new milestone



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IMAGE: Experimental configuration of the Ytterbium experiment at the Helmholtz Institute in Mainz with physicist Dr. Dionysis Antypas.
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Credit: photo / ©: Dionysis Antypas

A reflection always reproduces the objects as a mirror image, instead of just individual parts or individual parts in a completely different orientation. All or nothing, the mirror can not reflect a little. This illustrates a principle of fundamental symmetry in nature. For decades, physics assumed that the laws of nature in our world and in the mirror world would be identical, that parity would be preserved. Then, in 1956, within the scope of elementary particles, or more precisely in the field of weak interaction, researchers found a violation of this principle. The parity violation has been a subject of scientific research since then. The physicists of the Johannes Gutenberg University of Mainz (JGU) have recently managed to observe the parity violation at the atoms of iterbium with different neutron numbers. The initial effect of the measurements is to confirm the predictions of the Standard Model of particle physics that atoms with different neutron numbers would demonstrate violation of parity. The research was published in the famous Physics of nature newspaper.

The parity violation effect increases with the number of neutrons

The violation of parity is only known in the weak interaction, one of the four fundamental forces of nature. It was discovered for the first time in beta decay in 1956 at the atoms of 1979, and later it was studied in several elements. In 1995 at the University of California at Berkeley, Professor Dmitry Budker began performing precision measurements on the ytterbium element, a rare earth metal. It was this work that he brought with him when he arrived at the University of Mainz in 2014. "Our research involves several isotopes of the iterative. Isotopes are atoms with the same amount of protons but different neutron numbers in the nucleus," said Dr. Dionysis Antypas of Helmholtz Institute of Mainz (HIM). "We select a chain of four seven iberbium isotopes and confirm the Standard Model's predictions: the more neutrons are in the nucleus, the greater the effect of parity violation," said Antypas, who summarized the results of four years of work in the project.

The comparison of the effect on different isotopes was the first proposal by Professor Victor Flambaum in 1986. Flambaum, Australian physicist at the University of New South Wales, has been a member of the Gutenberg Research College of the University of Mainz (GRC) for two years and conducts collaborative research with scientists of the JGU. Physicists performed the research using a device at the Helmholtz Institute in Mainz: in the presence of an electric and magnetic field, the atoms of ytterbium are excited by laser light and the amplitude of the parity violation has been measured.

The results prepare the way for later investigations on the nucleus of iberbio

"The latest discoveries mark a significant milestone in the investigation into the violation of atomic parity," said Budker, who summarizes the data. "They are also a very important framework in the path to future research objectives." The measurements of scientists also offer information about an additional Z boson. Bosons Z mediate weak interaction. The scientists in the field speculate on the existence of an additional Z boson, referred to as "Z prime" or "Z" with a much smaller mass than the Z boson established.

In the future, Budker and Antypas plan to study the nucleus of terbium to determine the distribution of their neutrons and study the weak interaction between their nucleons. These projects are in line with the MESA program and the projects of the PRISMA + Excellence Cluster at the Johannes Gutenberg University in Mainz.

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Related links:

https: //budkeruni-mainz.of / – Budker Group

https: //budkeruni-mainz.of /? page_id =20 – Parity violation in Ytterbium

https: //www.wave mainz.of / – Helmholtz Institute of Mainz (HIM)

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