A group of 50 international physicists, led by UC Riverside's Ann Heinson, has detected for the first time a subatomic particle, the top quark, produced without the simultaneous production of its antimatter partner -- an extremely rare event. The discovery of the single top quark could help scientists better explain how the universe works and how objects acquire their mass, thereby assisting human understanding of the fundamental nature of the universe. The heaviest known elementary particle, the top quark has the same mass as a gold atom and is one of the fundamental building blocks of nature. Understood to be an ingredient of the nuclear soup just after the Big Bang, today the top quark does not occur naturally but must be created experimentally in a high-energy particle accelerator, an instrument capable of recreating the conditions of the early universe. For the full article: Click Here A naked quark beats Britney without knickers: pants down!

Hi DA,

I have reviewed the papers that Heinson's group has produced over the years. One phrase that is either in the abstract or the conclusion sections keeps recurring. For example, one recent paper is

http://arxiv.org/abs/hep-ex/0604020

In the abstract to this paper we see the phrase: "No evidence for a single top quark signal is found."

An announcement of the new discovery is expected to appear in the Physical Review Letters. I suppose that we will see what we see. My gut feel on this one is that they don't really have much. I could well be wrong though, but I am not holding my breath.

Dr. R.

Was it, or was it not, accepted for publication in PRL? That will tell quite a bit about it.

Hi DA,

The term used in the article that you mention above is "submitted." If a free top quark had been found, it would be big news - not a PRL!

To be fair about this I should mention that these people, and there are a lot of them and they are all named as author/contributors, are spending lots of time developing methods to "sort the wheat from the chaff." They are have put considerable energy into the means of studying and analysing these collision events. That by itself is a worthy effort and will almost certainly produce something good.


Dr. R.

I agree. The most amazing thing about this research is not the discovery of a naked top quark. Rather, as you point out, that they can gather the stats and perform the analysis.

http://arxiv.org/abs/hep-ex/0612052

Looks like PRL material to me. They just verify an aspect of the standard model, namely that because the weak interaction can change the flavor of quarks, you can produce the top quark without producing its antimatter partner (but you must produce another anti-quark, of course). This is important because you can then measure some unknown parameters.