Higgs Boson Conservation

SneakyG

If there is not a conservation of mass, then what happens to higgs-bosons? Are they destroyed, or decay into something else (if that is even possible...)?

Drakkith

There is a conservation of mass, so I don't understand what you are asking.
Also, the higgs boson, when mediating it's field, does so as a virtual particle, not a real one, so there are no decays.

Bill_K

Higgs bosons are extremely short-lived (~10^-26 sec) and decay in many different ways. For example, h → γ + γ or h → Z⁰ + Z⁰. Z⁰'s of course immediately decay also, perhaps into μ⁺ + μ^-. These decay patterns are how Higgs events are identified.

EDIT: The Higgs lifetime depends on what mass it has. For the observed mass around 125 GeV the lifetime is closer to 10^-23 sec

montadhar

Is there a conservation of mass at all ? I thought the conservation is for energy.

Drakkith

Conservation of mass IS conservation of energy. The best example I can think of is in electron-positron annihilation that produces 2 gamma ray photons. The rest mass of both particles is converted into energy and radiated away. The mass is not gone however, as any system that includes those photons still has the exact same mass, it has simply moved.

montadhar

I doubt that can be called a conservation of mass, it has the same energy converted from mass-energy into photons. But photon's mass are 0

SneakyG

There is not a conservation of mass, but there is for energy.

Drakkith

Yes, that is why conservation of mass IS conservation of energy. The reverse is also true in the case of two photons producing an electron-positron pair.

Drakkith

I don't think that is correct: http://en.wikipedia.org/wiki/Mass_conservation

montadhar

http://en.wikipedia.org/wiki/Mass_co...ion#Exceptions

what has been implied previously

Drakkith

I'm not sure I see your point. This is exactly what I've been saying.

montadhar

no it is not. I get what you are trying to say, but it is not right to say that.

If there was a conservation of mass, then if you measure the mass of the universe at anytime it will always show the same exact number.
But that is not the case, because of the Electron-Positron example. If a pair annihilated and then you measure the mass of the universe, it will show a different number

new mass = previous mass - (electron + positron)

but does that mean that the mass disappear ? No, and that is your point, they are transformed into other form of energy. But just because they have the ability to form the previous masses again and return to the old number, doesn't make the mass value always constant.

But when talking about Conservation of energy, in the annihilation, the energy of the photons didn't pop out of nothing. They were stored in Mass-energy (E = mc^2), and then got transformed into photons. So the energy (including mass-energy) value always stays constant when measured at anytime.

montadhar

To answer SneakyG's question, it is what Bill_k said, It decays.

Drakkith

No, this is 100% wrong. IF we could measure the mass of the universe, it would be exactly the same before AND after the annihilation of the electron-positron. Energy has mass and it is conserved.

montadhar

If what you say is true, then Photons are massive, and they shouldn't move at c

Drakkith

Photons have no REST mass. They have energy and they do, in fact, contribute to gravitation.

As an example, if you take a box made out of perfect mirrors and put light in it, it will have MORE mass than an identical box with no light in it.

montadhar

This is exactly why Conservation of energy holds while Conservation of mass doesn't


http://en.wikipedia.org/wiki/Conservation_of_mass

http://en.wikipedia.org/wiki/Conservation_of_energy

If you are talking about Mass-Energy, or the Energy content in mass, then I would agree.
but the mass is not conserved.

According to GR, it is the energy (Mass-energy included) that contributes to Gravitation, so Photons are included because they have energy not mass.