New ATLAS particle part of 'everyday mass'

This boson isn’t the Higgs

While we’ve been paying all our attention to the elusive Higgs boson, the ATLAS experiment has turned up another particle which researchers say could be responsible for shed light on* much of the mass of “everyday objects”.

The new object, known as chi-b(3P), is the first confirmed brand-new particle discovered at the Large Hadron Collider (LHC), and is discussed in this Arxiv paper, submitted to Physical Review Letters.

In their press release, the researchers, led by teams from the Universities of Birmingham and Lancaster, say the new object is formed when a beauty quark – a.k.a. a bottom quark – combines with an antiquark to bind together (the release doesn’t tell El Reg how that binding takes place without annihilation, which is a pity).

The quark-antiquark binding, the researchers say, is mediated by the strong nuclear force, which is why “a lot of the mass of everyday objects comes from the strong interaction we are investigating using the chi-b”, said Lancaster’s ATLAS group head Professor Roger Jones.

The pairing also makes the chi-b(3P) different to the Higgs: it contains two particles, whereas the Higgs is a single, indivisible particle.

Lighter partners of the chi-b(3P) have been observed for many years, but while predicted by theory, this is the first time the chi-b(3P) itself has been spotted in signals from the LHC. It was a needle-in-a-haystack task, as is pretty much all ATLAS analysis, with the new particle’s decay signal discovered among the billions of particle collisions the instrument produces. ®

Bootnote: The original first paragraph was inaccurate, and has since been corrected.

Sponsored: Designing and building an open ITOA architecture