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Particle that only has mass when moving in one direction observed for first time

https://phys.org/news/2024-12-particle-mass.html

Excerpt:

For the first time, scientists have observed a collection of particles, also known as a quasiparticle, that’s massless when moving one direction but has mass in the other direction. The quasiparticle, called a semi-Dirac fermion, was first theorized 16 years ago, but was only recently spotted inside a crystal of semi-metal material called ZrSiS. The observation of the quasiparticle opens the door to future advances in a range of emerging technologies from batteries to sensors, according to the researchers.

.....The team’s analysis showed the presence of semi-Dirac fermions at the crossing points. Specifically, they appeared massless when moving in a linear path but switched to having mass when moving in a perpendicular direction. Shao explained that ZrSiS is a layered material, much like graphite that is made up of layers of carbon atoms that can be exfoliated down into sheets of graphene that are one atom thick. Graphene is a critical component in emerging technologies, including batteries, supercapacitors, solar cells, sensors and biomedical devices.

“It is a layered material, which means once we can figure out how to have a single layer cut of this compound, we can harness the power of semi-Dirac fermions, control its properties with the same precision as graphene,” Shao said. “But the most thrilling part of this experiment is that the data cannot be fully explained yet. There are many unsolved mysteries in what we observed, so that is what we are working to understand.”

U.S. appeals court tosses Nasdaq diversity rules for company boards

https://www.axios.com/2024/12/12/nasdaq-board-diversity-regulations-appeals-court?

Excerpt:

A federal appeals court on Wednesday struck down the Nasdaq’s diversity disclosure rules for companies listed on the stock exchange, which were designed to boost the representation of women and minority directors on boards.

.....The conservative-majority New Orleans-based 5th U.S. Circuit Court of Appeals ruled the Securities and Exchange Commission did not have the power to approve the rule that required companies to ensure women and minority directors were on their boards or provide an explanation of why this was not the case.