Question on Particle Physics (i.e. the "God Particle")

Analog

Lifer
Jan 7, 2002
12,755
3
0
I was reading in the national geographic special on the new accelerator in Europe:

http://ngm.nationalgeographic....ticle-interactive.html

The Higgs Boson is supposed to be 200 times heavier than a proton. If that's the case, then how can it be a component of a Proton? I.e. doesn't the individual components of a proton (quarks, gluons etc) have to add up to its mass? I must be missing something, because quarks and gluons are also heavier than protons? Perhaps relativity has something to do with this?

Thanks
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
First rule of particle physics, particle physics is really cool.

Anyway, particle physics refers to the energy of a particle. Very rarely do they talk about its rest mass (and that's only really useful with the elementary set of protons, neutrons and electrons).
 

Analog

Lifer
Jan 7, 2002
12,755
3
0
Originally posted by: Born2bwire
First rule of particle physics, particle physics is really cool.

Anyway, particle physics refers to the energy of a particle. Very rarely do they talk about its rest mass (and that's only really useful with the elementary set of protons, neutrons and electrons).

Probably 100 to 200 times the mass of a proton, The Higgs particle is unstable: It will last less than a millionth of a billionth of a billionth of a second before decaying into a spray of other particles.

When it says 100 to 200 times the mass of a proton, then it must be comparing apples to apples, and I interpret that as rest mass. If it meant energy (as in mc^2), then why not say the same for the proton? :confused:
 

f95toli

Golden Member
Nov 21, 2002
1,547
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As born2wire has alraady pointed out: When particle physicists talk about "mass" they are always refering to the ENERGY of the particle; which is why the unit is usually MeV or GeV (eV=1 electrion volt=1.6022e-19 Joule).
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
Originally posted by: Analog
Originally posted by: Born2bwire
First rule of particle physics, particle physics is really cool.

Anyway, particle physics refers to the energy of a particle. Very rarely do they talk about its rest mass (and that's only really useful with the elementary set of protons, neutrons and electrons).

Probably 100 to 200 times the mass of a proton, The Higgs particle is unstable: It will last less than a millionth of a billionth of a billionth of a second before decaying into a spray of other particles.

When it says 100 to 200 times the mass of a proton, then it must be comparing apples to apples, and I interpret that as rest mass. If it meant energy (as in mc^2), then why not say the same for the proton? :confused:

Particle physics mainly deals with the realm of relativistic particles. Most of the particles that they are interested in do not occur at a high enough rate at room temperature. They have to accelerate particles to relativistic speeds and then collide them with various targets to achieve a total energy high enough to allow these particles to exist. It would be meaningless to talk about rest mass in this case because the interactions and observations would be of the particles moving at relativistic speeds. Under these terms, it's more appropriate and easier to consider the energy of the particle. The special theory of relativity relates mass and energy so there is no difference between the references.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: f95toli
As born2wire has alraady pointed out: When particle physicists talk about "mass" they are always refering to the ENERGY of the particle; which is why the unit is usually MeV or GeV (eV=1 electrion volt=1.6022e-19 Joule).

Well, sorta. High energy physicists operate in h(bar) = c = 1 units. Whenever they say GeV, they are actually saying GeV/c^2 where c = 1.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: Born2bwire
Originally posted by: Analog
Originally posted by: Born2bwire
First rule of particle physics, particle physics is really cool.

Anyway, particle physics refers to the energy of a particle. Very rarely do they talk about its rest mass (and that's only really useful with the elementary set of protons, neutrons and electrons).

Probably 100 to 200 times the mass of a proton, The Higgs particle is unstable: It will last less than a millionth of a billionth of a billionth of a second before decaying into a spray of other particles.

When it says 100 to 200 times the mass of a proton, then it must be comparing apples to apples, and I interpret that as rest mass. If it meant energy (as in mc^2), then why not say the same for the proton? :confused:

Particle physics mainly deals with the realm of relativistic particles. Most of the particles that they are interested in do not occur at a high enough rate at room temperature. They have to accelerate particles to relativistic speeds and then collide them with various targets to achieve a total energy high enough to allow these particles to exist. It would be meaningless to talk about rest mass in this case because the interactions and observations would be of the particles moving at relativistic speeds. Under these terms, it's more appropriate and easier to consider the energy of the particle. The special theory of relativity relates mass and energy so there is no difference between the references.

It's not meaningless to talk about rest mass at all. It's the minimum energy in the center of mass frame required to produce a particle. That's why the opposing beams in a ring accelerator are so nice, the center of mass frame is the same as the laboratory frame.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: Analog
I was reading in the national geographic special on the new accelerator in Europe:

http://ngm.nationalgeographic....ticle-interactive.html

The Higgs Boson is supposed to be 200 times heavier than a proton. If that's the case, then how can it be a component of a Proton? I.e. doesn't the individual components of a proton (quarks, gluons etc) have to add up to its mass? I must be missing something, because quarks and gluons are also heavier than protons? Perhaps relativity has something to do with this?

Thanks

The Higgs isn't part of a proton. You can make a Higgs by taking two protons and adding kinetic energy. The sum of the energy of the protons' rest masses and the kinetic energy can produce the rest mass of the Higgs.
 

firewolfsm

Golden Member
Oct 16, 2005
1,848
29
91
If the higgs even exists. People become far too caught up in contemporary physics theory and forget that that's exactly what it is, theory.

Remember when we talked about string theory as if it were fact?
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: firewolfsm
If the higgs even exists. People become far too caught up in contemporary physics theory and forget that that's exactly what it is, theory.

Remember when we talked about string theory as if it were fact?

Higgs is basically part of the standard model which is very very successful. String theory is pretty far fetched...
 
Sep 12, 2004
16,852
59
86
Originally posted by: firewolfsm
If the higgs even exists. People become far too caught up in contemporary physics theory and forget that that's exactly what it is, theory.

Remember when we talked about string theory as if it were fact?
The standard model has been pretty accurate thus far and the Higgs particle is an essential part of it. Hopefully the Higgs boson exists as predicted. If not it's going to blow a huge hole in what we think we already know since it's essentially the last missing piece.

And string theory still has legs as Superstring and M-theory.
 

Analog

Lifer
Jan 7, 2002
12,755
3
0
Originally posted by: silverpig
Originally posted by: Analog
I was reading in the national geographic special on the new accelerator in Europe:

http://ngm.nationalgeographic....ticle-interactive.html

The Higgs Boson is supposed to be 200 times heavier than a proton. If that's the case, then how can it be a component of a Proton? I.e. doesn't the individual components of a proton (quarks, gluons etc) have to add up to its mass? I must be missing something, because quarks and gluons are also heavier than protons? Perhaps relativity has something to do with this?

Thanks

The Higgs isn't part of a proton. You can make a Higgs by taking two protons and adding kinetic energy. The sum of the energy of the protons' rest masses and the kinetic energy can produce the rest mass of the Higgs.

Check the link from National Geographic. They claim the Higgs does come out of colliding two protons together.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: Analog
Originally posted by: silverpig
Originally posted by: Analog
I was reading in the national geographic special on the new accelerator in Europe:

http://ngm.nationalgeographic....ticle-interactive.html

The Higgs Boson is supposed to be 200 times heavier than a proton. If that's the case, then how can it be a component of a Proton? I.e. doesn't the individual components of a proton (quarks, gluons etc) have to add up to its mass? I must be missing something, because quarks and gluons are also heavier than protons? Perhaps relativity has something to do with this?

Thanks

The Higgs isn't part of a proton. You can make a Higgs by taking two protons and adding kinetic energy. The sum of the energy of the protons' rest masses and the kinetic energy can produce the rest mass of the Higgs.

Check the link from National Geographic. They claim the Higgs does come out of colliding two protons together.

Yes, but it's not part of a proton. A proton cannot decay into a Higgs. What happens is when you smash the protons together you compress their rest mass energy (E=mc^2) plus their kinetic energy into a little ball. This little ball can form a Higgs with the addition of all this energy.

Imagine playing with LEGO. You take two bricks (protons), add a whole bunch of others (kinetic energy), and you end up with a giant space robot (Higgs). The robot was never contained in a single brick.
 

Analog

Lifer
Jan 7, 2002
12,755
3
0
Originally posted by: silverpig
Originally posted by: Analog
Originally posted by: silverpig
Originally posted by: Analog
I was reading in the national geographic special on the new accelerator in Europe:

http://ngm.nationalgeographic....ticle-interactive.html

The Higgs Boson is supposed to be 200 times heavier than a proton. If that's the case, then how can it be a component of a Proton? I.e. doesn't the individual components of a proton (quarks, gluons etc) have to add up to its mass? I must be missing something, because quarks and gluons are also heavier than protons? Perhaps relativity has something to do with this?

Thanks

The Higgs isn't part of a proton. You can make a Higgs by taking two protons and adding kinetic energy. The sum of the energy of the protons' rest masses and the kinetic energy can produce the rest mass of the Higgs.

Check the link from National Geographic. They claim the Higgs does come out of colliding two protons together.

Yes, but it's not part of a proton. A proton cannot decay into a Higgs. What happens is when you smash the protons together you compress their rest mass energy (E=mc^2) plus their kinetic energy into a little ball. This little ball can form a Higgs with the addition of all this energy.

Imagine playing with LEGO. You take two bricks (protons), add a whole bunch of others (kinetic energy), and you end up with a giant space robot (Higgs). The robot was never contained in a single brick.

That makes a lot of sense. I knew there was a reason I nominated you for moderator... :)
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
Originally posted by: Biftheunderstudy
LEGO and giant space robots....I'm in the wrong field.

What did I say? Particle physics is really cool. I swear nobody ever reads my posts.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: Born2bwire
Originally posted by: Biftheunderstudy
LEGO and giant space robots....I'm in the wrong field.

What did I say? Particle physics is really cool. I swear nobody ever reads my posts.

Yep it is. And the theory behind it is really nice too. Being in experiment kind of sucks though as you have to get a grant for several billion dollars to build a new lab every decade or two.
 

firewolfsm

Golden Member
Oct 16, 2005
1,848
29
91
From what I've heard, the Standard Model is the best theory we have that combines the fundamental particles, but recent experiments have begun to deviate from what the standard model expected. We've patched it so account for these experiments, but that's usually a hint that things are going downhill.

We'll find out more in a couple weeks when the LHC goes online.
 

RideFree

Diamond Member
Jul 25, 2001
3,433
2
0
Originally posted by: silverpig
Originally posted by: Analog
That makes a lot of sense. I knew there was a reason I nominated you for moderator... :)

:D
Dear silverpig,
They just changed it - from ":D" - to ": D ;" without the spaces.

 

bsobel

Moderator Emeritus<br>Elite Member
Dec 9, 2001
13,346
0
0
Originally posted by: firewolfsm
If the higgs even exists. People become far too caught up in contemporary physics theory and forget that that's exactly what it is, theory.
Remember when we talked about string theory as if it were fact?

Used to? M-Theory is still the leading canidate for the GUT, all 5 flavors of string theory fold up nice and pretty into it.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: bsobel
Originally posted by: firewolfsm
If the higgs even exists. People become far too caught up in contemporary physics theory and forget that that's exactly what it is, theory.
Remember when we talked about string theory as if it were fact?

Used to? M-Theory is still the leading canidate for the GUT, all 5 flavors of string theory fold up nice and pretty into it.

Not really... Most physicists favour a modification/addition to the standard model over string theory. It's still only accepted as a purely outside shot in the dark.

Let me put it this way: You're buying a house. You have your down payment set, you have your financing in order and you've budgeted for the monthly mortgage payments. But you still have that lotto ticket for the weekend...
 

Eeezee

Diamond Member
Jul 23, 2005
9,922
0
76
Originally posted by: Analog
Originally posted by: Born2bwire
First rule of particle physics, particle physics is really cool.

Anyway, particle physics refers to the energy of a particle. Very rarely do they talk about its rest mass (and that's only really useful with the elementary set of protons, neutrons and electrons).

Probably 100 to 200 times the mass of a proton, The Higgs particle is unstable: It will last less than a millionth of a billionth of a billionth of a second before decaying into a spray of other particles.

When it says 100 to 200 times the mass of a proton, then it must be comparing apples to apples, and I interpret that as rest mass. If it meant energy (as in mc^2), then why not say the same for the proton? :confused:

Mass IS energy. That's what's so great about high energy physics!

We're not smashing two protons together at arbitrary speeds and seeing what comes out and saying "A proton is made of all of these particles we've seen." That doesn't make any sense by our current modes of understanding.

I can smash any two particles into each other, and if their energy is great enough I can create another particle (provided a few quantities are conserved, such as lepton number - although there are of course people searching for lepton number violation, etc.)

Take 2 protons, give them A LOT of energy and smash them into each other. Hopefully you see a Higgs boson (we'll know it from the stuff that the Higgs turns into, their respective energies, and their solid angles - my bet is on H->ZZ->eeee)