gentle giant of science

Peter Higgs was a gentle man who wanted a quiet life. However, fate had other plans for him. In 1964, after returning to his home in Edinburgh after a failed weekend camping trip, he came up with an idea that would become his one of the most important components of the Standard Model of particle physics: the Higgs mechanism. Ta. In 2012, the Higgs boson predicted by his theory was finally discovered at the European Institute for Nuclear Physics (CERN), providing the experimental basis for a physical model that describes three of his four fundamental forces of nature. was provided.

Higgs summarized his ideas in a two-page scientific paper entitled “Symmetry Breaking and the Mass of Gauge Bosons.” Initially, the paper was rejected by major European physics journals as having no obvious relevance to physics. But then he added a paragraph mentioning the possibility of observable consequences of his idea and submitted his paper to an American physics journal. physical review letterSimilar ideas were studied by physicists Robert Braut and François Unglert, and independently by Gerald Guralnik, CR Hagen, and Tom Kibble, and these two groups also published research in the same journal . However, perhaps as a result of an additional paragraph predicting the physical consequences of his theory, Higgs’ name became associated with the hypothesis, and eventually his four known forces in nature became It formed the basis of a successful effort to integrate the two. : Weak electromagnetic interaction.

The concept developed by Higgs and colleagues was applied to superconductivity (a phenomenon in which certain materials become completely conductive when cooled below a certain critical temperature) by Nobel Prize-winning condensed matter physicist Philip W. Anderson. Built on. Zero electrical resistance. In fact, it’s easiest to understand the idea in this context.

Electromagnetism is a long-range force that underlies nearly every physical process that governs chemistry and life on Earth. The repulsive force between her two negatively charged electrons, although weak, is felt throughout the visible universe. In our modern relativistic quantum physics understanding of the universe, forces are transmitted by the exchange of virtual particles. In this model, electromagnetism is understood as due to the exchange between electrons of virtual photons, which are electromagnetic quanta. The actual photon is the fundamental quantum that makes up light and all observable electromagnetic phenomena.

According to this understanding, because photons have no mass, electromagnetism is a long-range force, and therefore virtual photons can be exchanged between arbitrarily far apart electrons, requiring negligible energy for the exchange. There is only that.

Superconductivity is one of the most remarkable quantum mechanical phenomena that can be observed in macroscopic materials. It took almost 50 years after its experimental discovery for a theoretical explanation of superconductivity to be established. (In 1913, Heike Kamerling Onnes received the Nobel Prize in Physics for the discovery of superconductivity. John Bardeen, Leon N. Cooper, and J. Robert Schriefer collaborated for the development of superconductivity theory. won his 1972 Nobel Prize).

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Theoretical explanations involved the formation of special quantum states filled with “Cooper pairs.” A Cooper pair is a pair of electrons that, under certain conditions, are favorable for energetically condensing and bonding, and once bonded, can flow unhindered through a material.

One of the many strange properties of superconductors is that they are impermeable to electromagnetic fields. The strong electric field vanishes exponentially just below the surface of the superconducting material. This is called the Meissner effect. This happens because as photons propagate through the material through this special Cooper pair state, they behave as if they were giant particles rather than massless particles. However, the electromagnetic field quickly dissipates within the surface of the material because the force transmitted by giant particles must be short-range rather than long-range.

Higgs (along with Blaut, Englert, Guralnik, Hagen, and Kibble) realized that similar phenomena could occur in the relativistic quantum fields of particle physics. In this case, instead of electron pairs condensing in matter, the quantum field associated with the new subatomic particle could condense into the vacuum of empty space. As a result, background fields that permeate the entire space can have a significant impact. When a previously massless particle interacts with this field, its flow is impeded, as if it had gained mass, similar to how photons in a superconductor act as giant particles.

At the time, this may have seemed like just an interesting curiosity.Perhaps this journal is physics letters Rejected Higgs’ paper. However, three years later, Steve N. Weinberg and Abdus Salam independently revived the old model proposed by Sheldon Glashow, showing that this “Higgs mechanism” combines electromagnetism with the weak forces acting within the nucleus of an atom. I realized that integration is possible. Responsible for nuclear radiation.

It was shown that the equations describing the weak force could be put into a form similar to those in electromagnetism, but only if the particles that are carriers of the weak force (now called W and Z particles) are very heavy; The difference is that it is more than 80 times its mass. As heavy as a proton. The problem was that if we added an explicit term to the equation to give mass to these particles, the resulting theory would make meaningless predictions, making many interactions infinitely stronger.

Weinberg and Salam realized in 1967 that if there is a new background quantum field in nature, the Higgs field, and that W and Z particles interact with it, even if at a fundamental level these particles Even though they have no mass, if the Higgs field exists throughout the universe, particles behave as if they were huge. If the photon did not interact with the Higgs field, it would remain massless. In this way, we can integrate the W and Z particles and photons into a single theory. If the Higgs field did not exist in nature, all particles would have no mass and the two forces would appear identical. But if the Higgs field existed, the W and Z particles would appear huge, the weak force would suddenly become short-range, and could only be expressed at subnuclear scales, while electromagnetism would be the same as we know and love today. will continue to be a long-range force. Perhaps even more surprising, the Higgs field may be considered responsible for the observed mass of almost all elementary particles in nature. Anything that strongly interacts with this field behaves as if it has a large mass. Those with weaker interactions have less mass. And those that didn’t interact at all don’t get mass.

In 1979, Weinberg, Salam, and Glashow won the Nobel Prize for their integration of electromagnetism and the weak force, and in 1984, the W and Z particles were experimentally discovered in Cologne and Carlo Rubbia, and in 1984, Simon van Del Mer won the Nobel Prize that year. Physics for discovery.

All that remained to fully verify the electroweak unification was the discovery of a quantum associated with the mysterious new Higgs field. In 2012, the Higgs boson was observed experimentally at CERN, the same place where his W and Z particles were discovered, leading to one of the most beautiful theoretical and experimental stories in modern particle physics. It was completed.

Although Higgs appreciated the beauty of the discovery, he was not thrilled on a personal level. He later said that the discovery of the Higgs boson, which led to his 2013 Nobel Prize win (co-authored with François Unglert), had “ruined my life”. He is not a man who likes to be in the spotlight, and for almost his 50 years he has lived in relative anonymity, as a figure known only in physics circles. When Nobel Prize-winning physicist Leon Lederman wrote a popular book in 1993 calling the Higgs boson the “God particle,” he was not amused. The Higgs field would have made our observable universe possible. A problem they made up. Lederman later said he had intended to call the particles “fuck particles,” but his editor forced him to change the name. Having known and worked with Leon, I wonder if this was a joke, but we’ll never know.

All of us who knew Peter recognized him as a kind, quiet and gentle man who enjoyed theoretical and mathematical exploration and the friendship of his colleagues. I first met him around 1980 when I was attending a particle physics summer school in Scotland, where Glashaw and two subsequent Nobel laureates, Gerald Thoeft and Barry Barish, were also attending a particle physics summer school. He was giving a lecture. Peter preferred to stay behind the scenes and mingle with others, even as a junior graduate student like me (I was completing my PhD at the time).

His kindness and humility made as much of an impression on me as the important theoretical discoveries associated with his name. For Higgs was both a scholar and a gentleman. That’s the greatest compliment I can give to anyone, but it’s very rare that I get to say that. We have lost an important scientist. We have lost another wonderful person. It was an honor and honor to know him.