What to Expect from the L.H.C. Reboot

http://www.newyorker.com/tech/elements/what-to-expect-from-the-rebooted-large-hadron-collider

by jonbaer • 11 years ago

15 2 11 years ago

sgt101• 11 years ago

The article claims that 1000's of Higg's events were detected. My belief is that CMS saw 20 ish events and Atlas about 200. Is there anyone who actually knows?

mattheww• 11 years ago

This is not a very straight-forward question to answer. The short answer is that both CMS and ATLAS detected a couple thousand Higgs events.

The long answer depends on your definition of detected. As you probably know, the Higgs decays into many different combinations of particles. In some of these cases, we have very little chance of determining whether there was a Higgs in the event. In fact, only in H(iggs) -> ZZ -> 4l(eptons), do we stand a reasonably good chance of saying whether a specific event contains the Higgs. In this channel, CMS and ATLAS both observed ~20 events.

The next two most sensitive channels are H->WW->2l+2nu (neutrino) and H->2photon. In the most Higgs-enriched regions that have been constructed, the contribution from Higgs is ~10% in H->WW->2l+2nu and ~20% in H->2photon. So in these channels, we have very little chance to say whether a specific event contained a Higgs, but if we look at all the events, we see features that wouldn't be present if there weren't any Higgs bosons. The contributions from Higgs in these channels are a few hundred events in CMS and ATLAS.

Then there are even less sensitive channels, which means we have even less chance to say whether a specific event contains a Higgs. CMS and ATLAS probably detected a few hundred to a thousand or so events each in these channels.

What to Expect from the L.H.C. Reboot

Related Stories