• Physics 15, s105
The ATLAS Collaboration has detected triple W-boson manufacturing—a uncommon occasion that would ultimately provide indicators of latest physics.
The World Huge Net was invented at CERN in 1989 as a technique to share knowledge from particle-physics experiments. Now a kind of experiments, ATLAS, is sharing knowledge that carries the label “WWW” for a unique cause. Sifting by 20 billion proton-proton collisions from Run 2 at CERN’s Giant Hadron Collider (LHC), the ATLAS group has recognized round 270 occasions producing three W bosons . By measuring these uncommon occasions, the researchers have supplied one other high-precision take a look at of the usual mannequin of particle physics—specifically, concerning boson-boson interactions.
In the usual mannequin, bosons carry the basic forces: for instance, W and Z bosons carry the weak power, whereas photons carry the electromagnetic power. The brand new measurements will not be the primary by which three weak-force bosons have been noticed in particle collisions (see Synopsis: Hat Trick Commentary for Bosons). Nevertheless, that is the primary time that observers have pinpointed that the bosons are W’s, relatively than a mix of W’s and Z’s. By extracting W-only occasions, the ATLAS group was in a position to goal particular interactions, together with ones the place a single W decays into three lower-energy W’s. These interactions may probably be delicate to hypothetical particles that aren’t predicted in the usual mannequin.
At collision energies of 13 TeV, the ATLAS group measured the WWW cross part (a measure of the likelihood of this occasion) to be 820 femtobarns, which is barely larger than the usual mannequin prediction. To inform whether or not this overproduction is actual or only a statistical fluke, researchers will want extra knowledge, which is more likely to come from the lately began LHC Run 3 (see Analysis Information: Good Omens for Run 3).
Michael Schirber is a Corresponding Editor for Physics Journal primarily based in Lyon, France.
- G. Aad et al. (ATLAS Collaboration), “Commentary of WWW manufacturing in pp collisions at
with the ATLAS detector,” Phys. Rev. Lett. 129, 061803 (2022).