Latest Issue of Science News

Science Ticker

Your daily roundup of
research news
Ashley Yeager
Science Ticker

More precision added to mass estimate of electron

Sponsor Message

Guest post by Andrew Grant

The electron has been weighed with unprecedented precision, researchers report February 19 in Nature. Its new and improved mass, 17 times as precise as the previous best estimate, is 0.000548579909067 atomic mass units. (An atomic mass unit is one-twelfth the mass of a carbon-12 atom, or 1.66 trillionths of a trillionth of a gram.) German researchers calculated the mass by analyzing a lone electron bound to a bare carbon nucleus.

Adding a few decimal places of confidence may seem trivial, but physicists need precise measurements of known particles to have a chance of discovering a new particle or force that interacts with them.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.