B How much energy do you need to split up a proton?

[TR094]

TL;DR Summary

how much energy do you need to split up a proton?

is it even possible to split pu a proton and how much energy would it take to do that? i heard that it requires so much that it would make new a quark.

 

[Vanadium 50]

Since there is no such thing as half a proton, you'll have to better define what you mean by "splitting: one in order to have a productive discussion.

 

[berkeman]

Welcome to PF.

TL;DR Summary: how much energy do you need to split up a proton?

is it even possible to split pu a proton and how much energy would it take to do that? i heard that it requires so much that it would make new a quark.

I see from your New Member Introduction post that you are still in high school, and very interested in particle physics. Good for you.

How much reading have you been doing about the standard model of particle physics? That will help you understand what particles can be split into more fundamental particles, and the energies required to accomplish that:

https://en.wikipedia.org/wiki/Particle_physics

 

[phinds]

i heard that ...

@TR094, just so you are aware, "I heard that ... " is not an acceptable citation here on PF. We have no idea what you actually heard.

 

[TR094]

Since there is no such thing as half a proton, you'll have to better define what you mean by "splitting: one in order to have a productive discussion.

like is it possible to take a quark out of a proton? like an up quark

 

[Orodruin]

like is it possible to take a quark out of a proton? like an up quark

No. A free quark would have non-trivial color charge. QCD is confining, meaning such states cannot be isolated.

 

[nightvidcole]

At MINIMUM you'd need ~140 MeV for pion production, which can be interpreted as removal of a quark followed by creation of a quark-antiquark pair.

 

[PeroK]

TL;DR Summary: how much energy do you need to split up a proton?

is it even possible to split pu a proton and how much energy would it take to do that? i heard that it requires so much that it would make new a quark.

As a side note, you could try my "beginners' guide to baryons", which might give you a flavour of particle physics:

https://www.physicsforums.com/insights/a-beginners-guide-to-baryons/

 

[TR094]

As a side note, you could try my "beginners' guide to baryons", which might give you a flavour of particle physics:

https://www.physicsforums.com/insights/a-beginners-guide-to-baryons/

Thanks, I'll look into it!

 

[ohwilleke]

TL;DR Summary: how much energy do you need to split up a proton?

is it even possible to split pu a proton and how much energy would it take to do that? i heard that it requires so much that it would make new a quark.

No. A free quark would have non-trivial color charge. QCD is confining, meaning such states cannot be isolated.

Deconfinement In Quark-Gluon Plasma

QCD (quantum chromodynamics, which is the physics of the strong force) confines all quarks and gluons into strong force bound systems called hadrons up to a certain threshold of energy.

All hadrons are naturally unstable except protons and bound neutrons, which are stable indefinitely. Free neutrons have a mean lifetime of about 15 minutes. All other hadrons have mean lifetimes before they naturally decay into something else that ranges from on the order of microseconds to something on the order of 10^-24 seconds.

If you apply enough energy, protons and other hadrons in a system can dissolve into what is called a "quark-gluon plasma", which is made up of deconfined quarks and gluons, and as noted in the link: "the formation of a quark–gluon plasma occurs at the temperature of T ≈ 150–160 MeV, the Hagedorn temperature, and an energy density of ≈ 0.4–1 GeV/fm³." It takes beam strengths vastly greater than 1-2 GeV to get that energy density, realistically, something on the order of low to mid-TeV energy beam strength (more than a thousand times greater).

CERN claims to have created such as state for the first time in the year 2000. The only experimental facilities currently capable of creating quark-gluon plasma the Large Hadron Collider at CERN and Brookhaven National Laboratory's Relativistic Heavy Ion Collider.

Quark-gluon plasma, a.k.a. QGP, is unstable and hadronizes (i.e. breaks up into confined quarks and gluons in hadrons) as it cools below the Hagedorn temperature. Only a tiny amount of it has been created in human history and the QCP created has been extremely short-lived.

QGP requires conditions too extreme to be created naturally in the post-Big Bang universe (after the first hour or two, or perhaps even less) by any known natural means.

Disrupting Protons To Make New Particles

Far less proton-proton collision energy is needed to lead to a high energy physics event that produces end products that are something other than two protons (some combination of leptons like electrons, muons, taus, and neutrinos, photons, and other hadrons, including hadrons more massive than the protons that were in the initial state, since their kinetic energy can be converted into mass), which could also credibly be described as splitting a proton.

The first experiment to accelerate a proton to break up an atomic nucleus was by Cockroft and Walton in 1932, but that only broke up a residual nuclear force bond between particles in a meta-stable uranium atom. Over time, colliders and their immediate predecessor technologies grew more powerful (from the link in this paragraph):

Proton-proton colliders starting in the 1960s were finally reaching a point where the collision could produce something other than two protons afterwards on a consistent basis, although there may have been examples of this earlier (in the 1950s) at somewhat lower energies (10s to 100s of MeVs) that I have missed in a brief review.

 

[TR094]

Deconfinement In Quark-Gluon Plasma

QCD (quantum chromodynamics, which is the physics of the strong force) confines all quarks and gluons into strong force bound systems called hadrons up to a certain threshold of energy.

All hadrons are naturally unstable except protons and bound neutrons, which are stable indefinitely. Free neutrons have a mean lifetime of about 15 minutes. All other hadrons have mean lifetimes before they naturally decay into something else on the order of microseconds to something on the order of 10^-24 seconds.

If you apply enough energy, protons and other hadrons in a system can dissolve into what is called a "quark-gluon plasma" is deconfined quarks and gluons, and as noted in the link: "the formation of a quark–gluon plasma occurs at the temperature of T ≈ 150–160 MeV, the Hagedorn temperature, and an energy density of ≈ 0.4–1 GeV/fm³." It takes beam strengths vastly greater than 1-2 GeV to get that energy density, something on the order of the mid-TeV energy beam strength.

CERN claims to have created such as state for the first time in the year 2000. The only experimental facilities currently capable of creating quark-gluon plasma the Large Hadron Collider at CERN and Brookhaven National Laboratory's Relativistic Heavy Ion Collider.

Quark-gluon plasma, a.k.a. QGP, is unstable and hadronizes as it cools below the Hagedorn temperature. Only a tiny amount of it has been created in human history and the QCP created has been extremely short-lived.

QGP requires conditions too extreme to be created naturally in the post-Big Bang universe (after the first hour or two, or even less) by any known natural means.

Disrupting Protons To Make New Particles

Far less proton-proton collision energy is needed to lead to a high energy physics event that produces end products that are something other than two protons (some combination of leptons like electrons, muons, and neutrinos, photons, and other hadrons, including hadrons more massive than the protons that were in the initial state, since their kinetic energy can be converted into mass), which could also credibly be described as splitting a proton.

The first experiment to accelerate a proton to break up an atomic nucleus was by Cockroft and Walton in 1932, but that only broke up a residual nuclear force bond between particles in a meta-stable uranium atom. Over time, colliders and their immediate predecessor technologies grew more powerful (from the link in this paragraph):

View attachment 336653

View attachment 336654
Proton-proton colliders starting in the 1960s were finally reaching a point where the collision could produce something other than two protons afterwards on a consistent basis, although there may have been examples of this earlier (in the 1950s) at somewhat lower energies (10s to 100s of MeVs) that I have missed in a brief review.

Thx so much! Oh yeah where was the tiny amount of qgp made?

 

[ohwilleke]

Thx so much! Oh yeah where was the tiny amount of qgp made?

Brookhaven is on the eastern part of Long Island near New York City.

The Large Hadron Collider crosses the border between Switzerland and France:

 

[Orodruin]

Deconfinement In Quark-Gluon Plasma

QCD (quantum chromodynamics, which is the physics of the strong force) confines all quarks and gluons into strong force bound systems called hadrons up to a certain threshold of energy.

All hadrons are naturally unstable except protons and bound neutrons, which are stable indefinitely. Free neutrons have a mean lifetime of about 15 minutes. All other hadrons have mean lifetimes before they naturally decay into something else on the order of microseconds to something on the order of 10^-24 seconds.

If you apply enough energy, protons and other hadrons in a system can dissolve into what is called a "quark-gluon plasma", which is made up of deconfined quarks and gluons, and as noted in the link: "the formation of a quark–gluon plasma occurs at the temperature of T ≈ 150–160 MeV, the Hagedorn temperature, and an energy density of ≈ 0.4–1 GeV/fm³." It takes beam strengths vastly greater than 1-2 GeV to get that energy density, realistically, something on the order of low to mid-TeV energy beam strength.

CERN claims to have created such as state for the first time in the year 2000. The only experimental facilities currently capable of creating quark-gluon plasma the Large Hadron Collider at CERN and Brookhaven National Laboratory's Relativistic Heavy Ion Collider.

Quark-gluon plasma, a.k.a. QGP, is unstable and hadronizes (i.e. breaks up into confined quarks and gluons in hadrons) as it cools below the Hagedorn temperature. Only a tiny amount of it has been created in human history and the QCP created has been extremely short-lived.

QGP requires conditions too extreme to be created naturally in the post-Big Bang universe (after the first hour or two, or perhaps even less) by any known natural means.

Disrupting Protons To Make New Particles

Far less proton-proton collision energy is needed to lead to a high energy physics event that produces end products that are something other than two protons (some combination of leptons like electrons, muons, taus, and neutrinos, photons, and other hadrons, including hadrons more massive than the protons that were in the initial state, since their kinetic energy can be converted into mass), which could also credibly be described as splitting a proton.

The first experiment to accelerate a proton to break up an atomic nucleus was by Cockroft and Walton in 1932, but that only broke up a residual nuclear force bond between particles in a meta-stable uranium atom. Over time, colliders and their immediate predecessor technologies grew more powerful (from the link in this paragraph):

View attachment 336653

View attachment 336654
Proton-proton colliders starting in the 1960s were finally reaching a point where the collision could produce something other than two protons afterwards on a consistent basis, although there may have been examples of this earlier (in the 1950s) at somewhat lower energies (10s to 100s of MeVs) that I have missed in a brief review.

I mean, yes and no, if so you could equally well say you saw free gluons because you did deep-inelastic scattering.

 

[ohwilleke]

you could equally well say you saw free gluons because you did deep-inelastic scattering.

Maybe so. Deep-inelastic scattering usually isn't described in that way, while QGP is almost always described that way, but it is a fair point and to some extent boils down the exactly how "free" is defined.

 

[Vanadium 50]

Despite that voluminous post, a QGP absolutely does not eject a quark from a proton or otherwise "split" a proton. The size of a QGPO is no bigger than a nucleus, and actually because of Lorentz contraction, smaller.

 

[ohwilleke]

Despite that voluminous post, a QGP absolutely does not eject a quark from a proton or otherwise "split" a proton. The size of a QGPO is no bigger than a nucleus, and actually because of Lorentz contraction, smaller.

Did you mean to say "no bigger than a nucleon"? A nucleus of U-238, for example, could be much bigger than a proton.

QGP causes the quarks to cease to be confined, and causes the proton to no longer exist, with the proton replaced by "free" color charged particles. Its failure to occupy more volume isn't inconsistent with a proton being deconfined and hence "split" into free components.

 

[snorkack]

Deconfinement In Quark-Gluon Plasma

QCD (quantum chromodynamics, which is the physics of the strong force) confines all quarks and gluons into strong force bound systems called hadrons up to a certain threshold of energy.

Which in QCD is expected to be infinite.
Note that merely infinite binding energy (consistent with all observations so far) does not suffice to show standard model to be correct. The standard model specifically predicts that the colour force on a lone quark should be constant at long distances. If the colour force decreased at distance but the potential still diverged to infinity, that would be a standard model violation. If the colour force increased further at distance, that would also be a standard model violation!

All hadrons are naturally unstable except protons and bound neutrons, which are stable indefinitely. Free neutrons have a mean lifetime of about 15 minutes. All other hadrons have mean lifetimes before they naturally decay into something else that ranges from on the order of microseconds to something on the order of 10^-24 seconds.

If you apply enough energy, protons and other hadrons in a system can dissolve into what is called a "quark-gluon plasma", which is made up of deconfined quarks and gluons, and as noted in the link: "the formation of a quark–gluon plasma occurs at the temperature of T ≈ 150–160 MeV, the Hagedorn temperature, and an energy density of ≈ 0.4–1 GeV/fm³." It takes beam strengths vastly greater than 1-2 GeV to get that energy density, realistically, something on the order of low to mid-TeV energy beam strength (more than a thousand times greater).

How do you define temperature? If two protons collide at total energy 300 MeV (150 MeV per particle), what is their temperature?

Quark-gluon plasma, a.k.a. QGP, is unstable and hadronizes (i.e. breaks up into confined quarks and gluons in hadrons) as it cools below the Hagedorn temperature. Only a tiny amount of it has been created in human history and the QCP created has been extremely short-lived.

QGP requires conditions too extreme to be created naturally in the post-Big Bang universe (after the first hour or two, or perhaps even less) by any known natural means.

High energy collisions go on all the time, in cosmic rays.

Disrupting Protons To Make New Particles

Far less proton-proton collision energy is needed to lead to a high energy physics event that produces end products that are something other than two protons (some combination of leptons like electrons, muons, taus, and neutrinos, photons, and other hadrons, including hadrons more massive than the protons that were in the initial state, since their kinetic energy can be converted into mass), which could also credibly be described as splitting a proton.

The first experiment to accelerate a proton to break up an atomic nucleus was by Cockroft and Walton in 1932, but that only broke up a residual nuclear force bond between particles in a meta-stable uranium atom. Over time, colliders and their immediate predecessor technologies grew more powerful (from the link in this paragraph):

Proton-proton colliders starting in the 1960s were finally reaching a point where the collision could produce something other than two protons afterwards on a consistent basis, although there may have been examples of this earlier (in the 1950s) at somewhat lower energies (10s to 100s of MeVs) that I have missed in a brief review.

There is a trivial way of producing "something other than two protons afterwards" - namely two protons and one photon (bremsstrahlung). No threshold energy (it goes on all energies to infrared and radio waves).
There is one low energy reaction which we all depend on, yet we have never ever observed, that splits a proton and produces a hadron heavier than proton. Its crosssection sucks because it is a weak process:
p+p=d+e⁺+ν_e
At higher energies, first exotic particles we could produce with better (electromagnetic) crosssection would be
p+p=p+p+e⁺+e^-
from 1022 keV
A better crosssection to split a proton and produce a heavier hadron would be
p+p=p+n+π⁺
above 140 MeV

Now, d behaves like it contained distinct p and n. Its binding energy is mere 1,1 MeV per nucleon, 2,2 MeV total. Bigger nuclei are more bound. α has average binding energy over 7 MeV, and the binding energy of the last neutron over 20 MeV. At bigger nuclei, the average binding energy grows over 8 MeV (peaking at Ni-62) but the binding energy of last nucleon drops. They still behave like they consisted of distinct protons and nucleons.
Low energy collisions of nucleons and nuclei still behave like nuclei consisted of nucleons. But from 140 MeV on, there is the energy to produce extra quarks (starting with pions).

What is the qualitative difference between a proton-proton collision where the two protons produce a pi meson and turn into neutron but supposedly stay individual hadrons throughout, and a proton-proton collisions where the two protons supposedly merge into quark-gluon plasma and then turn back into distinct hadrons? Can you trace them?
In the basic reaction
p+p=p+p+p+p~
can you identify which two of the three outgoing protons were the original incoming ones, and which one is the one newly created as pair of the antiproton? They are indistinguishable particles.

 

[ohwilleke]

Which in QCD is expected to be infinite.

Do you dispute that quark-gluon plasma is a thing?

How do you define temperature? If two protons collide at total energy 300 MeV (150 MeV per particle), what is their temperature?

There are a standard means of conversion that is basically a function of kinetic energy per volume.

High energy collisions go on all the time, in cosmic rays.

Not with the energy density necessary to produce QGP.

There is a trivial way of producing "something other than two protons afterwards" - namely two protons and one photon (bremsstrahlung). No threshold energy (it goes on all energies to infrared and radio waves).

Yeah, that is a trivial exception.

can you identify which two of the three outgoing protons were the original incoming ones, and which one is the one newly created as pair of the antiproton? They are indistinguishable particles.

So what?

The point is that we know that somehow or other, there was not simply non-disruptive conservation of the original particles that did not involve a disruption of the original QCD bound structures, and this definition is one plausible way to interpret what someone means when they talk about "splitting the proton", a term which doesn't have a meaning which is as obvious as splitting a large many nucleon nucleus of an atom.