2021: A year physicists ask, ‘What’s beyond the Standard Model?’
This article was originally published at Conversation. Publications that contributed articles to Space.com’s Expert Voices: Op-Ed & Insights.
Aaron McGowan, Principal Lecturer in Physics and Astronomy, Rochester Institute of Technology
If you asked a physicist like me to explain how the world works, my lazy answer might be: “It follows the Standard Model.”
Standard model Basic physics explanation of how The universe do. It has gone through more than 50 trips around Sun although experimental physicists are constantly probing cracks in the base of the model.
With a few exceptions, it has stood up to this scrutiny, passing experimental test to experimental test with flying colors. But this hugely successful model has conceptual holes that suggest a little more needs to be learned about how the universe works.
I am a neutrino physicist. Neutrinos represent three of the firstThe 7 elementary particles in the Standard Model. They pass people on Earth at all times of the day. I study the properties of interactions between neutrinos and ordinary matter particles.
Related: Mass simulation of the universe probes the mystery of the spooky neutrino
In 2021, physicists around the world performed a number of exploratory experiments in the Standard Model. The teams measured the basic parameters of the model more precisely than ever before. Others study those pieces of knowledge where the best empirical measurements do not quite match the predictions of the Standard Model. And finally, groups have built more powerful technologies designed to push the model to its limits and be capable of discovering new particles and fields. If these efforts are successful, they could lead to a more complete theory of the universe in the future.
Fill hole in Standard Model
In 1897, JJ Thomson discovered the first elementary particle, the electron, using nothing more than glass vacuum tubes and wires. More than 100 years later, physicists are still uncovering new pieces of the Standard Model.
The Standard Model is a prediction framework that does two things. First, it explains what the fundamental particles of matter are. These are things like electrons and quarks that make up protons and neutrons. Second, it predicts how these matter particles interact with each other using “messenger particles”. These are called bosons – they consist of photons and Higgs boson – and they communicate the fundamental forces of nature. The Higgs boson was discovered until 2012 after decades of work at CERN, particle collider in Europe.
The Standard Model is extremely good at predicting many aspects of how the world should work, but it has some flaws.
Notably, it doesn’t include any description of Gravitation. While Einstein’s General Theory of Relativity describe how gravity works, physicists have yet to discover a particle that transmits gravity. A proper “Theory of Everything” would do everything the Standard Model can, but also include messenger particles that inform how gravity interacts with other particles.
Another thing the Standard Model can’t do is explain why any particle has a certain mass – physicists have to directly measure the masses of particles with experiments. Only after experiments have provided physicists with these precise masses can they be used for predictions. The better the measurements, the better predictions can be made.
Recently, physicists in a group at CERN measured How powerful does the Higgs boson itself feel. Another CERN group also measured the mass of the Higgs . boson more accurate than ever. And finally, there’s also been progress in measuring the mass of neutrinos. Physicists know neutrinos have masses greater than zero but less than currently detectable mass. A team in Germany has continued to refine techniques that would allow them to directly measure the mass of the neutrino.
Hints of new forces or particles
In April 2021, the members of Muon g-2 experiment at Fermilab published their first measurement of the magnetic moment of muon. The muon is one of the elementary particles in the Standard Model, and the measurement of one of its properties is the most accurate to date. The reason this experiment is important is that the measurement does not completely match the Standard Model predictions for magnetic moments. Basically, muon doesn’t work as it should. This finding may indicate undetected particles interacting with muon.
But at the same time, in April 2021, physicist Zoltan Fodor and his colleagues showed how they used a mathematical method called Lattice QCD to correctly calculate the magnetic moment of muon. Their theoretical prediction is different from the old ones, which still work in the Standard Model and, importantly, are consistent with the experimental measurements of the muon.
The disagreement between the previously accepted predictions, this new result, and the new prediction must be reconciled for physicists to know if the experimental results are indeed outside the Standard Model.
Physicists have to juggle between generating mind-bending ideas about the reality that make up the theory and technology so advanced that new experiments can test those theories. 2021 is an important year for the development of physics experimental tools.
First, the world’s largest particle accelerator, the Large Hadron Collider at CERN, was retired and underwent some significant upgrades. Physicists just restarted the facility in October and they plan to start Next data collection will run in May 2022. The upgrades have increased the power of the collider so that it can creates a collision at 14 TeV, up from the previous limit of 13 TeV. This means that the tiny batches of protons moving in beams around the circular accelerator together carry the same energy as an 800,000 pound (360,000 kg) passenger train traveling at 100 mph (160 mph). km/h). With these amazing energies, physicists can detect new particles that are too massive to be seen at lower energies.
Several other technological advancements have been made to help search dark matter. Many astrophysicists believe that dark matter particles, which currently do not fit the Standard Model, can answer some striking questions regarding the way gravity bends around stars – known as stars. gravitational lens – as well as the speed at which stars rotate in spiral galaxies. Projects like the Cryogenic Dark Matter Search have yet to find dark matter particles, but the teams have develop larger and more sensitive detectors will be implemented in the near future.
Of particular relevance to my work with neutrinos is the development of new detectors such as Hyper-Kamiokande and DUNE. Using these detectors, scientists hope to be able to answer questions about a fundamental asymmetry in the way neutrinos oscillate. They will also be used to monitor proton decay, a proposed phenomenon that certain theories predict will occur.
The year 2021 highlights some of the ways the Standard Model doesn’t explain all the mysteries of the universe. But new measurements and new technology are helping physicists move forward in their search for the Theory of Everything.
This article was republished from Conversation under a Creative Commons license. Read original article.
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