The news wires have been buzzing this week with the possible
discovery, at the Large Hadron Collider (LHC) in Switzerland, of the
long-sought Higgs Boson—aka the “God particle.” Just that nickname is enough to
set journalistic hearts a-flutter. But, as always in high-energy physics,
there’s more to the drama than meets the eye via standard news accounts. This
is not to say that I, a mere dilletante, really understand it, but reading lots
of accounts and seeing several videos has made some things clearer. Perhaps I
can convey that to a few readers.
To
begin with, the real action here lies with the proposed Higgs field, the Higgs Boson being only an indication that the theorized
field actually exists. But the Higgs field is not like the usual fields—the
magnetic field around earth, or the gravitational field around our sun, or an
electromagnetic field around a generator—we’re familiar with. Those fields
require an energy source, like the sun, to generate them; furthermore, the size
of the force (of gravity say, from the sun) varies with the distance from the
energy source. So, the farther we get from the sun or the earth, the less force
we feel from its gravity field. In short, most fields dissipate with distance
because the number of particles constituting the field (virtual particles) is
fewer (this last is due to the quantum understanding of fields, which used to
be thought of as continuous, but are now thought of as composed of particles,
like all else).
The
Higgs field is not like that. Theoretically at least, the Higgs field remains
the same throughout the universe even though there’s no source generating it
(if I understand it correctly, the Higgs field would have been generated in the
first nano-seconds of and by the Big Bang). Its force doesn’t dissipate with
distance because of this lack of a specific energy source. It’s everywhere.
This
means something fundamental: there really is no empty space anywhere. The
entire universe and all in it is saturated with a Higgs field (or as many as
five Higgs fields) all the time. And of course, like any field, what makes up a
Higgs field are Higgs bosons (subatomic particles). It is believed that these
Higgs bosons interact with all subatomic particles, dragging on them, thus
giving them their mass. Some have compared the Higgs field to an ocean of
molasses; any particle with mass that tries to get through it feels a drag on
itself—and this is what is meant by its mass. The only particles that don’t get
dragged on by a Higgs field are the virtually massless ones: photons (light
particles), gluons (force particles between quarks) and gravitons (the
theorized and yet undiscovered particles that express gravity). The sun-generated
neutrinos are also, like ghosts, exempt from the Higgs field’s drag. So,
because of the Higgs bosons dragging on it, a particle such as a top quark
(quarks are the components of protons) has a very large mass—indeed it is 350,000
times the rest mass of an electron (even though both particles are about the
same ‘size.’)*
So
why is it so important to find evidence of Higgs Bosons and hence Higgs fields?
There are two basic reasons. First, finding the boson will firmly,
experimentally establish that the Higgs field exists, and therefore, that it is
what gives matter its fundamental property of mass. This is key because in
order to rationalize and complete the standard theories of particle physics, an
explanation is needed for this phenomenon of mass. That is, why should some
subatomic particles have no mass (such as photons), while others have varying
degrees of mass (such as the W and Z bosons carrying the weak nuclear force). This would then fill out the Standard
Model in a way that would be impossible if the Higgs Boson could not be
detected.
Second,
there is a related and perhaps even greater problem that the “b” portion of the
Higgs Boson experiment is attempting to solve: the problem of symmetry. Symmetry
gets to the fundamental problem of why there is matter in the first place. In the Standard Model, that is, matter and its
oppositely-handed twin, antimatter, are conceived as symmetrical twins. For
every piece of matter, there is a corresponding piece of anti-matter, and when
the two meet each other (as has been demonstrated by experiment), they wipe
each other out. The question is, why, if the two are equal or symmetrical, there
is so much more matter than antimatter in the Universe we know? And related to
this: given that there was, in the very first moment of the Big Bang, also
symmetry between the force particles, and hence between the forces they convey,
why are there differences now? That is, at the first moment of creation, photons
were the same as the W and Z bosons. There was no distinction between the weak
nuclear force (W & Z bosons being its messenger particles) and the
electromagnetic force (photons being its messenger particles). But there is
now.
The
big question thus becomes: how did this apparently universal symmetry yield to
the Universe we have now? What gave matter its edge, its ability to exist? What
gave the Universe its ability to produce all the matter we see, including
ourselves? Why didn’t it remain perfectly symmetrical? The physicist Michio Kaku,
talks about this in terms that would almost convince one he was talking about God
or Genesis. He refers to the physicists’ “dream of perfect symmetry” at the
beginning of the Big Bang where everything in the Universe would have been the
same. He calls it a state of “perfection” where particles and forces and fields
were all the same. But then something, some slight “imperfection,” caused the
Universe to fall into a less symmetrical state. Some tiny fluctuation led to
the appearance of distinction: distinct
forces, distinct fields, and matter itself with its myriad distinctions. All of
which happens in logical sequence leading eventually to stars, galaxies and us,
which means, says Kaku,
“..everything
we see around us is nothing but a fragment of that original perfection.”
It
is this fall into asymmetry and all the
rest of our Universe that proceeds from it, that physicists find fascinating,
and that the discovery of the Higgs boson may help them, and us, understand.
There
is more to this, of course, and as one goes deeper it gets very complex and
very mathematical. But briefly, there is a relatively new theory called
supersymmetry, or SUSY, according to which all the currently known particles
have heavier supersymmetric partners, known as “sparticles:” quarks have their “squarks”
and photons have their “photinos.” And it may account for nature’s apparent preference
for matter over antimatter by positing not one but five Higgs fields with
asymmetry built-in, thus giving rise to the excess matter we see. All this
requires that physics would have to go way beyond the Standard Model as it is
now conceived. But that could be one perverse result of the LHC experiments.
For if, as now seems possible, the new particle recently announced at the LHC is
not a standard Higgs Boson, fitting perfectly into the Standard Model, but
rather a strange particle with an odd decay pattern, well then it’s a whole new
ball game. As one physicist put it recently:
“The Higgs sector particle not being the simplest
Higgs boson would be the first indication that, yes, there is new physics out
there. And that would provide tremendous momentum to the whole field.” (Christian
Science Monitor, July 5, 2012)
The discovery of the ‘God particle’ would, in that
case, turn out to be not the satisfying vision capping a century’s long search,
but in fact, the beginning of an entirely new quest and new model—one that might
finally be able to account for “dark matter” (fully 84% of the matter in the
Universe, about which almost nothing is known), gravity (and its messenger
particle the ‘graviton’), and the deep conundrum of matter itself.
So
stay tuned.
Lawrence DiStasi
[i] Just to keep
things clear, in the so-called Standard Model of quantum physics, there are
three sorts of particles: 1) matter particles like quarks, and electrons; 2) force
particles (akin to lumps of energy) like photons, gluons, and W and Z bosons;
3) the sought-after and possibly found Higgs particle. The last two can all be
classified as “bosons,” because they have the remarkable property of being able
to occupy the same place in space.
Need to read this 3 more times:):)
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