Chapter 168: A Heavy Particle?
Translator: Henyee Translations Editor: Henyee Translations
Yan Xinjue asked, “Weird?”
He walked over and stared at the computer screen. As he frowned, he said, “It does look weird. Our experiment is in the 1-10GeV segment, how did it go to 1TeV?”
Professor Grayer also looked at the screen.
There was a difference in magnitude of 1000 between GeV and TeV. This means that the particle beam in the collider tunnel had reached 1000GeV. Only 6GeV was needed to find the pentaquark.
1000GeV was an overkill.
When Professor Grayer heard Yan Xinjue’s question, he smiled and explained in a casual tone.
“I already said that this is to test the status of the collider, so this isn’t the actual experiment. If we aren’t limited by our budget, we can show off a 10TeV energy zone.”
Professor Grayer was just showing off.
He was almost bragging.
It did make sense. All of the world’s top theoretical physicists were gathered here. CERN wanted to show off their equipment.
How else would they let the world know how nutty their machine was?
The LHC could even reach 14TeV of collision energy, which meant that each particle would carry 7TeV of energy.
How scary was that?
The energy unit was used to describe the ma.s.s of a particle. For example, the ma.s.s of a hydrogen atom was about 1GeV, the Higgs particle found in 2012 was about 125 GeV.
The Shangzheng electron-positron collider is about 5GeV, magnitudes lower than the LHC.
It would take decades for China to catch up.
“… I don’t mean that the experiment range is strange,” said Lu Zhou. He poked at the computer screen and asked, “Did you not notice? There’s an unusual impact near the 750GeV range.”
“This isn’t a sign of a collision. It’s just a single two-photon signal. But it is strange how it appeared in the 750GeV zone,” murmured Professor Grayer. He rubbed his chin and continued, “But this isn’t uncommon. We always observe some special signals on ATLAS, so the data could just be a random error.”
Lu Zhou was still staring at the screen, he could not help but ask, “So this is common?”
Yan Xinjue nodded, “Yeah, it is. The signals generated by the collision are only 1% of the data. Therefore we usually guess the conclusion and verify it with experiments. You’ll get used to it.”
Particle physics was a very metaphysical thing.
Normally, atoms could not be “directly observed”. So in order to determine the existence of a particle, confidence was needed.
This was a statistical concept.
In particle physics, three standard deviations away from the mean was a “sign”, whereas five standard deviations was a “discovery”. Although the media often wrote “breakthrough progress” or “significant discovery”, most of them were only “signs”.
Therefore, they would need three-sigma to be a sign.
A temporary characteristic peak did not mean anything.
Particles could only be confirmed by repeating experiments and observing the particle on different detectors. When the confidence of the particle was above five standard deviations, it could be counted as a “discovery”.
Lu Zhou did not say anything else.
Soon after, the experiment continued.
A series of green dots appeared densely on the image with most of them concentrated around the 125GeV range.
However, Lu Zhou’s attention was still concentrated on the 750GeV zone.
Suddenly, another point jump appeared on the 750GeV zone.
Lu Zhou’s heart dropped. He then looked at Professor Grayer and asked, “What about the data on the CMS detector?”
There were many detectors in one orbit with ATLAS and CMS being the most sensitive.
There was a simple way to test if Lu Zhou’s observation was just simply an illusion. He would be correct if the observation was observed by both detectors at the same time.
When Professor Grayer heard Lu Zhou’s question, he had a weird expression.
“The data collected by the CMS is responsible for the lab upstairs. If you’re curious, wait a bit and I can take you there.”
Lu Zhou asked immediately, “Then will the test run impact data be recorded?”
Professor Grayer nodded and said, “Normally it would be archived. There isn’t much research value but I can give you a copy. It’s not cla.s.sified information anyway. But let me remind you that since this isn’t public data, you can’t use this in a thesis.”
Yan Xinjue asked curiously, “What did you find out?”
Lu Zhou thought and insisted on his own point of view. He said, “I think there’s something wrong with the 750GeV energy zone. From a statistical point of view, this could be described as random, but it feels far-fetched.”
Yan Xinjue asked jokingly, “Like from a mathematician’s perspective?”
Lu Zhou, “You could say so.”
Yan Xinjue sighed and said, “I know your research direction is mathematical physics but I have to remind you that even though mathematics is an important physics tool, not all physical phenomenon follows mathematical laws. 750GeV is way too large, the Higgs boson is only 125GeV. I think it’s just two-photon, the signal might not even be a collision.”
Yan Xinjue patted Lu Zhou’s shoulder and continued, “Don’t get caught up in the energy zone beyond 10GeV. We’re looking for the pentaquark particle. If you’re really OCD, rest a.s.sured, you won’t see any activity in the 750GeV energy zone again.”