[Marxism] Physicists Recover From a Summer’s Particle ‘Hangover’

Louis Proyect lnp3 at panix.com
Tue Oct 18 14:11:16 MDT 2016


NY Times, Oct. 18 2016
Physicists Recover From a Summer’s Particle ‘Hangover’
by George Johnson

As I sat last month in the cafeteria at CERN, the nuclear research 
center near Geneva that is home to the Large Hadron Collider, I looked 
out at the expanse of tables and wondered what all those young 
physicists were talking about.

Judging from their enthusiasm, they had recovered from the summer’s 
“diphoton hangover,” the nickname given to the disappointment that 
followed the coming apart, weeks earlier, of a striking observation — an 
excess number of photons hinting that some exotic new particle might be 
lurking behind the scenes, an encore to the Higgs boson.

Could it be a cousin of the Higgs, or a long sought particle of dark 
matter? The excitement led to a speculative bubble of papers seeking to 
explain what turned out to be a nonevent. What had jumped out as a 
pattern in the data was apparently a mirage, like seeing a pyramid on Mars.

A victim of its own success, particle physics has come to a turning 
point. For decades, the theorists have been calling the shots, 
predicting particles like the Higgs for the experimenters to find, 
plugging the holes in the cosmic puzzle. Now, with the pieces in place, 
in the form of the Standard Model, the theorists are hoping to push 
further, looking again to the experimenters to confront them with new 
things to theorize about — clues, perhaps, to an even deeper order.

As plates and utensils clattered around me, I thought of an earlier 
changing of the guard. In 1962 in this same cafeteria, a 32-year-old 
theorist named Murray Gell-Mann wrote a prediction on a napkin that 
helped set the course for the next half-century of research.

During the early decades of the 1900s, swashbuckling experimenters had 
run the show. Launching their instruments in balloons and carrying them 
to mountaintops, they brought back snapshots of cosmic ray particles 
that made no sense.

“Who ordered that?” Isidor I. Rabi, a renowned theorist, famously said 
after he learned of the muon — a fat, short-lived cousin of the 
electron. Then came interlopers called pions, kaons, lambdas, sigmas and 
xis.

Just three particles — electrons, protons and neutrons — seemed like 
enough to make the world. What were all of these extras? They didn’t fit 
into any existing scheme.

With pencil and paper, Dr. Gell-Mann devised one, doing for physics what 
Mendeleev, with his periodic table of the elements, had done for 
chemistry. Sorting the particles into clusters of eight and 10, Dr. 
Gell-Mann came up with a framework he called the Eightfold Way. It had 
nothing to do with Buddhism. He just liked the name.

Among the rows and columns of Mendeleev’s table there had been empty 
spaces — place holders for elements like germanium (a kin to carbon, 
silicon, tin and lead) that would not be discovered for years. And so it 
was with the gaps in the Eightfold Way.

If Dr. Gell-Mann’s math was right — a pretty good bet — there had to be 
a particle he called the omega minus. He described what to look for on a 
cafeteria napkin and handed it to a colleague, Nicholas Samios.

Two years later, Dr. Samios, one of the great experimenters of his 
generation, discovered the particle at Brookhaven National Laboratory on 
Long Island. (It had also been predicted by the Israeli physicist Yuval 
Ne’eman, who was sitting at lunch that day with Dr. Gell-Mann at CERN.)

 From then on, the theorists were ascendant. With its bona fides 
established, the Eightfold Way led to quarks, gluons and ultimately the 
Standard Model, a chart with its own holes to fill. One by one, the 
experimenters obliged until the keystone, the Higgs, was put in place, 
discovered with the Large Hadron Collider in 2012.

And that, for the theorists, led to a postpartum depression. Though now 
complete, the Standard Model (available on a T-shirt at the CERN gift 
shop) lacks the elegance one might like in a well-made universe.

There are matter particles and force particles with masses ranging from 
zero (photons and gluons) and near zero (neutrinos) to the top quark, 
which is as hefty as an entire atom of tungsten — an element whose name, 
in Swedish, means “heavy stone.”

The Higgs explains how particles acquired mass, but not why they were 
spit forth with such a hodgepodge of different values. Least satisfying 
of all, the Standard Model leaves out the most salient of forces, 
gravity, which is described by an entirely different theory.

Is this how the universe just happens to be? Or is there a grander 
theory that would demand that things be precisely this way? And so the 
search goes on.

There is no reason other than sheer stubbornness for human brains to 
assume that they are neurologically equipped to understand the finest 
details of creation. But those vibrant physicists in the CERN cafeteria 
didn’t seem burdened with existential angst.

As they lined up to bus their lunch trays, placing the dishes on a 
conveyor belt, I wondered for a moment about the fate of all those 
discarded napkins. All it might take is one, marked in pencil or ink 
with a unique scribble, to set particle physics off on its next adventure.

Beneath our feet, particles collided silently in the tunnels, striking 
more sparks to puzzle over.



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