With record-breaking precision, physicists just measured the most powerful particle

With record-breaking precision, physicists just measured the most powerful particle ...

Recent developments in particle physics have taken a toll. For years, researchers have used particles to make sure that the rules used to explain the Universe are in good standing.

Physicists using the Large Hadron Collider (LHC) have now measured the heaviest known elementary particle with an unprecedented amount of precision.

In an essential victory for the Standard Model of particle physics, the set of rules that determine the behavior of all particles that compose our world come with a margin of error that''s significantly smaller than the previous one, giving physicists a boost of confidence in the particle''s true mass.

This measurement might be the first step towards gaining a deeper understanding of how our Universe works.

The highest quark is referred to as the elementary particle, which is the most significant of all known elementary particles, which contribute to a fundamental component of our understanding of the Universe.

Importantly, it receives its mass from coupling with the elusive Higgs boson. This partnership is the strongest coupling at this scale that we know of in the Standard Model.


The greatest quark is what the top quark is decaying into. Once it''s been smashed into existence by a collider, the top quark can only decay through weak force, and it forms a W boson (and, in theory, a bottom quark).

If you''re a regular ScienceAlert reader, you may recognize the W boson as the reason behind the recent controversy.

Researchers have recently published a solid backlog of evidence that suggests that previous estimates of the W-boson''s mass might be incorrect.

If these findings are further confirmed, then it would suggest that the entire Standard Model might be incorrect.

This is where the greatest quark comes into play, and we can utilize its force to make predictions about both the Higgs boson and W boson, therefore getting the most exact measure is crucial.

"Remarkably, our knowledge of the very stability of our Universe depends on our combined knowledge of the Higgs-boson and the top-quark masses," a press release from the European Council for Nuclear Research (CERN), which led the study.

"We only know that the Universe is very close to a metastable state with the accuracy of the current measurements of the top-quark mass. In the long term, the Universe would be less stable, potentially disappearing in a violent event similar to the Big Bang."

While it may seem simple to''weigh'''' these particles, like we do regular objects, to see their mass, it''s still not that easy.

In devices such as the Large Hadron Collider, physicists smash together subatomic particles that are called protons to produce an elementary particle. Each collision results in a range of other particles being spat out, allowing researchers to investigate these byproducts in a controlled environment.

It''s still tricky to actually understand each particle''s properties. When we begin talking on these incredible small scales, we enter the quantum realm in which particles become a little fuzzy, and it''s difficult to pinpoint exactly what their mass is.

One strategy is to conduct an experiment a number of times and then statistically crush the findings.Another is to use different methods. In this case, researchers directly measured the particle while also conducting a measurement using other methods in combination with established theory (in this case, referred to as its pole mass measurement).

According to the CERN researchers, their new outcome is 0.12 GeV less sensitive than previously calculated based on the same data, making the particle 172.76 gigaelectron volts (give or take 0.3 of a giga electronvolt) quite similar to what we''d expect of standard models.

Recent top-quark mass measurement and uncertainty (left) and the most recent measurements (right). (CMS, LHC, CERN)

New analysis methods allow for better understanding of variables than previously to help improve accuracy.

The most recent analysis of collision data from the LHC''s Compact Muon Solenoid (CMS) detector in 2016 looked at five different properties of collision events that had produced a pair of top quarks. The properties they examined are dependent on what the mass of the top quark is, and previous studies had only examined three properties of the events.

The researchers then calibrated the dataset with great precision to determine which uncertainties were there. They could then extract these limitations and better understand them when it comes to selecting the best fit for the top-quark mass''s final value.

While this outcome in itself is a significant step forward for particle physics and a probable victory for the Standard Model, CERN says that even more precision will be obtained when the same approach is applied to the CMS detector in 2017 and 2018, without any future issues, already breaking records. The LHC was just switched on after a three-year shutdown, and is already breaking records.

It''s safe to say that with this updated mass measurement, and the techniques that led it, we''re about to get even deeper into our understanding of the darkest aspects of the Universe. Watch this space.

You can learn more about the CERN dataset.

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