What is mass: Q&A

Q:

It takes trillions of collisions to produce a few Higgs bosons, and they decay very quickly. However, if this boson is supposed to give things their mass, shouldn’t there be an abundant supply of Higgs bosons around us? This seems contradictory to me.
In other words, if they are not around us constantly, what gives me my mass?
According to our current description of the micro-world, called “quantum field theory”, all particles and forces are described by fields. A field is an association of a scalar, a vector or a matrix to each point in the space-time (which, by the way, is assumed to be continuous). Each field can oscillate, i.e. can be described as an superposition of harmonic oscillators, or simply waves. The point is: how do we see such waves? We have to transfer energy to those fields, for example by crashing two protons against each other. At this point, an oscillation can get enough energy so we can detect it with our instruments.
From another point of view, there is a link between the length you are exploring (in particle physics, usually in the range of 10^-15 m or less) and the energy of the collision (usually trillions of electron volts). In the end, our detectors are very very large microscopes. With the ordinary light you can probe distances down to  6.2 x 10^-5 cm to 7.5 x 10^-5 cm (the wavelength of red light), but if you want to see a DNA strand (50 Ångstrom in width) you have to use x-rays (0.01 to 10 nm). But at this point, you risk to break up a living cell! Red light has a wavelength that is simply too long to see such small structures. Well, the same applies to the inside of nucleus, but the “light” you have to use need to be MUCH more powerful – gamma rays, or you can use something completely different such as gluons, the carriers of the strong nuclear interaction, as we do at the LHC.
So, to finally answer the question, we are “soaked” in the Higgs field, we just don’t see it directly but we feel its presence by the mass. That said, keep in mind that there are other mechanism to give mass to particles. I assume you already know that most of the mass of ordinary matter is made by the nuclei, which in turn are made of protons and neutrons (the electron is ~2000 times lighter than the proton). Now, the mass of these particles is made by less than 50% by their “static” constituents, called “up” and “down” quarks  (personally, I study a fat relative of the “up” quark, called “top” quark, which is as heavy as a gold nucleus and lives just 10^-33 seconds). All the rest is made by the kinetic energy due to the exchange of gluons, and since E=mc^2 you interpret this kinetic energy as an overall mass. This mechanism has nothing to do with the Higgs boson and accounts for the largest part of the actual mass you see in everyday life.
But this is not the end of the story: from cosmology and astrophysics some years ago we discovered that all the protons and netruons (i.e.: stars and nebulae) represent ~5% of the whole mass of the Universe. Another 25% doesn’t seem to interact with light, and it’s called dark matter. The remaining 70% is a complete mystery, nicknamed dark energy, which is sort-of anti-gravity and is responsible of the increase in the expansion rate of the Universe
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s