Higgs boson and top quark coupled together
What does it mean?
Published: 24 July 2018 (GMT+10)
As of 4 June 2018, new results from the two independently run particle detectors at the Large Hadron Collider (LHC) in Geneva, Switzerland, establish the associated production of the Higgs boson together with top quarks. A report in the prestigious journal Nature stated:
The observations showed directly — for the first time — that the strength of the interactions between the Higgs and the top quark is consistent with the expectation of the Standard Model.1
The CMS collaboration of the European Council for Nuclear Research (CERN) has just published results,2 while its sister collaboration known as ATLAS, also at CERN, has also just submitted new results for publication.3 Both teams have reached a statistical significance exceeding the gold standard of five standard deviations. These results are said to prove that the quark’s interaction with the Higgs field is what causes quarks to have mass. Although physicists have had indirect evidence of it for some time, now we have direct proof that this hypothesis is correct. Precision measurements of the Higgs boson such as this give new clues of where to look for new physics. So what kind of new physics are physicists looking for, and why the fervent search?
The unnatural mass of the Higgs
No one knows the reason that some particles interact strongly with the Higgs field, giving them a large mass, while other particles react weakly, giving them a smaller mass. These so-called coupling strengths are treated as constants of nature that must be measured. According to the very successful Relativistic Quantum Field Theory (QFT), the Higgs mass should be 10¹⁷ (a hundred million billion) times larger than the 126 GeV that has been observed at the Large Hadron Collider, due to quantum mechanical (QM) interactions among the underlying quantum fields. This must mean that the QM interactions that make large positive contributions dozens of digits long to the Higgs mass have added to the large negative contributions dozens of digits long to give the Higgs its tiny resulting mass (cf. proton’s mass = 0.938 GeV).
Physics’ nightmare scenario
The actual Higgs mass that we have observed from the LHC is its rest mass plus quantum corrections predicted by QFT. Physicists are left to explain how the positive and negative factors for these quantum corrections, all dozens of digits long, have magically canceled out, leaving an extraordinarily tiny value behind. “It seems as inevitable that we have to face the ‘nightmare scenario’ and the unprecedented collapse of decades of speculative work.”4 The nightmare comes as the LHC has offered no path at all toward a theory of nature that better satisfies an evolutionary Big Bang worldview. Creationists, on the other hand, can have sweet dreams.
The Higgs field was first theorized to make the Standard Model (SM) of particle physics consistent. The Standard Model is a collection of theories that embodies all of our current understanding of fundamental particles and forces. It is supported by a great deal of experimental evidence, making predictions that match experiments to one part in 10 billion. Without the Higgs field to give particles mass, the SM would make nonsensical predictions such as probabilities greater than one for some interactions. With the discovery of the Higgs boson in 2012, the Standard Model (SM) of particle physics is now complete. One would think everybody should be celebrating this milestone achievement for high-energy physics. On the contrary, the singular reaction of particle physicist Kyle Cranmer expresses the sentiments of so many of his colleagues:
“We don’t like it.”5
Supersymmetry to the rescue
Supersymmetry theory says that the Standard Model particles each have a heavy supersymmetric twin: for the electron, there is the hypothetical “selectron”, for the quark, there is a “squark”, and so on. If supersymmetry is correct, there should be a whole new set of elementary particles to discover. These supersymmetry (SUSY) super-partners would give quantum corrections with opposite signs to the Higgs mass. Thus, with SUSY, it would not be unnatural for the Higgs mass to be at its measured value of 126 GeV. Are you beginning to get the feeling that physics may be losing its objectivity with SUSY? An article in Evolution News & Science Today states that physicists seem to be “expanding sets of hypotheses to avoid some embarrassing metaphysics.”6 Scientific American clearly reports the reason physicists have fallen in love with SUSY: “by far the biggest motivation for studying supersymmetry—it solves the conundrum of the Higgs hierarchy problem.”7 In other words physicists are making a fervent search for supersymmetry particles at the LHC because SUSY explains why the Higgs mass is low in a “natural” way, with no fine-tuning.
Despite the enormous effort to search for signs of supersymmetry in the LHC data, none have emerged so far. If supersymmetry is responsible for keeping the Higgs mass low, then sparticles should show up at energies not much higher than the Higgs mass. The fact that nothing has been found already rules out many popular forms of SUSY. Professor Chris Parkes, spokesman for the UK participation in the LHCb experiment, told BBC News, “Supersymmetry may not be dead, but these latest results have certainly put it into hospital.”8 He adds that superparticles are “running out of places to hide.”
Dragan Hajduković laments the situation in which particle physicists find themselves:
After three years of work at LHC, the experimental findings strongly confirm the Standard Model and have nearly eliminated supersymmetry as a possible physical theory… The current crisis is worsened by the fact that the long domination of supersymmetric theories has largely suppressed alternative thinking.4
Supersymmetry is dead… or is it?
Physicists gathered in Copenhagen on 22 August 2016, to settle a bet on supersymmetry. The original wager was made in 2000 just as construction began on the Large Hadron Collider. Twenty renowned physicists signed “Yes”, that at least one SUSY particle would be experimentally detected within a given amount of time, while twenty-four physicists signed “No.” As the declared losers, each who signed “Yes” was obliged to buy the winners who signed “No” a bottle of good cognac worth at least $100.
Yet not all theorists are ready to concede that supersymmetry is dead. “The fact that the Higgs fits the Standard Model means new physics is farther up the energy scale. We know it is there, we just don’t know if it is tomorrow or the next decade,” said Guido Tonelli, a professor at the University of Pisa in Italy and a leader in the Higgs hunt.9
The trick is that supersymmetry can never really be completely disproved:
It can always be tweaked so that sparticles appear only at energies that are just out of reach of the best existing colliders. Yet the more such tweaks are applied, the more they erode the elegance for which the theory is admired.10
Gian Giudice, head of CERN’s theory department, admits that these are difficult times for theoretical physicists: “Our hopes seem to have been shattered. We have not found what we wanted.”9
Concerning the new 4 June 2018 declaration from CERN about the coupling of the top quark and the Higgs, although the data analysis is not yet complete, at this point it seems unlikely something more than statistical anomalies will show up.11
Low Higgs mass invokes anthropic reasoning
To date, the Large Hadron Collider has not seen any new physics besides the Higgs particle. The laws of nature have turned out to not be “natural” in the way most particle physicists wanted them to be. This desire comes from the fact that physicists can see there are two logically viable explanations for the “unnatural” fine-tuning of the Higgs mass. Either:
- there is a God, and He created the universe very finely-tuned for life as we know it, or
- there is a very big ensemble of universes out there, and we just happen to be in a universe suitable for life as we know it. This collection of universes is commonly referred to as the “Multiverse.”
Within the hypothetical Multiverse, the laws of physics would be different in each individual universe:
Out of all these universes, only the ones with accidentally lightweight Higgs bosons will allow atoms to form and thus give rise to living beings. But this ‘anthropic’ argument is widely disliked for being seemingly untestable.12
Fine-tuning is no longer an issue to physicists who believe in the unfalsifiable existence of the Multiverse. By placing their faith in chance and a very large number of universes, evolutionary-minded physicists no longer have to explain why the Higgs mass is low in our universe. Thus they attempt to erase the fingerprints of God in His creation.
Christian physicists, on the other hand, can confidently proclaim that the created things they study clearly point to God's invisible attributes, namely His eternal power and Godhead. For by the witness of creation, no one has an excuse for unbelief in the Creator God.
References and notes
- Physicists cheer rendezvous of Higgs boson and top quark: Encounters between two subatomic particles support reigning theory, Nature, 8 June 2018; nature.com. Return to text.
- Sirunyan, A.M. et al. (CMS Collaboration), Observation of ttH Production, Physical Review Letters 120:231801, 4 June 2018; journals.aps.org. Return to text.
- ATLAS collaboration, Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector, 1 June 2018; arxiv.org/abs/1806.00425. Return to text.
- Hajduković, D.S., The signatures of new physics, astrophysics and cosmology? arxiv.org. Return to text.
- Cranmer, K., The Higgs Boson: A natural disaster!, Quantum Diaries; quantumdiaries.org. Return to text.
- Dr. Rob Sheldon quoted in Klinghoffer, D., To avoid the implications of cosmic fine-tuning, a continuing quest, Evolution News & Science Today, 22 August 2014; evolutionnews.org. Return to text.
- Wolchover, N., Supersymmetry fails test, forcing physics to seek new ideas, Quanta Magazine, 29 November 2012; scientificamerican.com. Return to text.
- Ghosh, P., Popular science theory running out of places to hide, BBC News, 12 November 2012; bbc.com. Return to text.
- Overbye, D., Yearning for new physics at CERN, in a Post-Higgs Way, The New York Times, 19 June 2017; nytimes.com. Return to text.
- A bet about a cherished theory of physics may soon pay out, The Economist, 12 Nov., 2016; economist.com. Return to text.
- Hossenfelder, S., The multiworse is coming, Backreaction, 13 March 2018; backreaction.blogspot.com. Return to text.
- Wolchover, N., What no new particles means for physics: Physicists are confronting their “nightmare scenario.” What does the absence of new particles suggest about how nature works?, Quanta Magazine, 9 August 2016; quantamagazine.org. Return to text.