Would it be possible to collide electrons with protons to get more energy than electron/electron and more accuracy than proton/proton collisions?
Colliding protons with electrons instead of electrons with positrons or protons with either protons or antiprotons is a completely different kind of experiment, that can give you different information from the other ones.First, at high collision energy the proton resolves into constituents, so you actually collide electrons with quarks. And that means that you generally don’t gain much in terms of centre of mass energy over an electron-positron collider. The colliding quark usually carries only a small fraction of proton momentum. And even if it happens to carry a most of the proton momentum, then the collision becomes highly asymmetric and most of the collision energy goes into movement of the centre of mass of the system.Second, it is difficult to create “new particles” in such a collision. In electron-positron collision colliding particles usually annihilate and entire collision energy is available to creation of new particles. In proton-proton you get many gluon-gluon collisions which can also turn the entire energy of colliding gluons into new particles. In electron-proton the electron and quark just scatter from each other and production of new particles occurs only during hadronization of the struck quark, or as a higher order process in the collision itself. In both cases only a fraction of collision energy goes into those new particles and the probability of producing them is lower. So, while electron-proton collisions are a great tool for studies of proton structure, they are not that great if you want to search for new physics. Unless that new physics contains particles like leptoquarks, that can be directly produced by fusion between an electron and a quark.So yes, electrons and protons can be collided and it has been done, but they are not a replacement for electron-positron or proton-proton, they are a complementary kind of experiment.
Why do the electrons not collide with or get attracted to the protons in the nucleus?
First, it is important to realize that there is an extremely low probability for an electron to be inside the nucleus. The probability of finding an electron in any given volume is the integral of the absolute square of its wave function over that volume. The wave functions for electrons depend on their angular momentum and it is only the s orbitals that do not vanish there. Even for the s orbitals, the volume of the nucleus is 10^15 times smaller than the region occupied by the electrons, so we’re talking about a very low probability.When, nonetheless, an electron is in the immediate neighborhood of a proton, it requires the weak interaction to combine to form a neutron. The interaction is actually in terms of one of the proton’s up quarks:e- + u → neutrino + d(The process actually is viewed as occurring in two parts:e- → W- + neutrinou + W- → dwhere W- is a weak intermediate vector boson)The u quark has charge +2/3 while the down quark has charge -1/3. The proton, comprised of two u and one d quark has changed to a neutron comprised of two d and one u quark. The electron is gone and a neutrino escapes.Weak interactions, as the name suggests, are quite rare, but this interaction and others involving the weak interaction do occur. There is a very very tiny effect of weak interactions on the energy levels of hydrogen, and this has been measured.The situation changes under extremely strong gravitation. When a star collapses, the central core is under such strong pressure that the electron orbitals are forced within the nucleus. This results in gravitational collapse. We sometimes see the resulting neutrino flux from a supernova and observe the resulting neutron star.
Why does the Large Hadron Collider use two proton beams instead of a proton beam and an anti-proton beam?
The advantage of using antiprotons colliding with protons is that the highest energy collisions are between valence quarks and antiquarks. Such collisions can produce very high energy off-shell gluons which can decay to pairs of new strongly interacting particles, or new gauge bosons. But at the extremely high energies of LHC protons, the valence quarks carry less momentum and the “sea” antiquarks do the job well enough, especially when you take into account how hard it is to produce, collect, and then accelerate antiprotons.Also, just considering Higgs boson production, which is dominated by gluon fusion, it does not matter if you use protons or antiprotons, clearly, and we can get much higher luminosity colliding protons.
What happens when a photon and a proton collide?
I am just getting to see your question now, with an excellent answer from Eli Pasternak. Just wanted to add some information that may encourage further thinking. The low energy photon which is in the long wavelength and lower frequency EM wave spectrum behaves like more a wave form than particle, thus can also pass through more easily such as through atoms or protons. Compared to that the high energy photon which has higher frequency and shorter wavelength, behaves more like a particle than wave, and can “strike” the proton, give it more momentum( like a smaller ball colliding with a larger ball), or bounce off of it, or get deflected, (or absorbed/merged)… more like a particle-particle interaction than wave-particle interaction. All this is consistent with the wave-particle duality of light( or matter ). Lower frequency light behaves more like wave on the wave-particle duality spectrum, and the higher frequency light behaves more like particles at the other end of the spectrum. One fascinating thing is that if a proton absorbs a photon, and gains some extra energy(mass), it will generally give it up in the form of a photon with a different or the same frequency or energy, and not continue to gain more and more energy(mass), which nature does not seem to allow… they must emit it out as photon also to prevent continued weight gain toward a more unstable nucleus. So many photons must strike a proton(nucleus) per second and if there was no way to give up the excess energy or transient gain in mass for each absorption scenario, or increase in momentum from collision, then a nucleus could never be able to maintain a certain mass, and would get bloated very fast and break into fragments, or explode. Nothing could exist if that innate mechanism of emitting out transiently gained energy or mass in the form of photon was not there… it appears to be an innate self preservation mode of atoms and sub-atomic particles in general… Kaiser T, MD.
When a stationary proton collides with a high energy proton, both starts to increase in speed, but how does the stationary proton gain speed?
Any one of average knowledge about scattering theory, will be able to answer,first the stationary proton is called a target, and the moving with high energy proton is called the projectile, which hits the target or collides with the target,so you need to rephrase your question,because stationary means it is at rest,Now when the collision occurs the projectile(moving proton),in any state the collision occurs,will supply the target with energy which activate it to move with speed,this is called inelastic collision,If you come running and collide with a stationary person,don`t you give him energy to move him for certaint distance within certain time,which means he gains speed due to the energy gained from your energy, but the total energy is conserved.
Do heads on collisions of protons in LHC occur in a complete vacuum?
Firstly,Complete vacuum is never possible . There has to be at least some gas molecules left behind unevacuated. But it iterates at ultra high vacuum.ULTRAHIGH VACUUM: the beam vacuum pressure is about 10^(–7) Pa in the beam pipe at cryogenic temperature (~5 K) because they want to avoid collisions with gas molecules, and lower than 10^–9 Pa close to Interaction Points, because in this part is where collisions take place.
What will happen if two electrons collide? Or in other words, can we fuse electrons?
A2AOOOOOOOOH BOY!!! YOU GON ON TO MAKE A DOOZY OF A WIRL-WIN AIN'TCHA?!?!Okay.....hypothetical scenario......2 electrons, are touching each other. Why did the world come to this. Well, we can't make 2 electrons touch each other, never, nada, not even God can do it, He'd break the rules that he made to create the universe. So you just have to accept that we won't be able to do it in hells chance, and the one in the LHC where they're colliding 2 protons? It's more in the sense making them more unstable as we push them so close that they just break apart because of the extreme amount of energy that the protons gain due to the reduced kinetic energy from repulsion. Now electrons........they're touching each other. You really want to do this?Okay, first thing is that due to the extreme proximity of these 2 same charges, they are acted by Coulomb forces of high values that it is just unimaginable to write down. The sudden acceleration of such high values causes them to be repelled from each other so fast that the photon produced by the electrons is of just way too high energy and frequency that if theories of mass being photons of extremely high frequencies is true, then the electron would've made mass instead of a photon right there itself. They'd be running away from each other at speeds that would make the Oh-My-God particle's speed look like a snail compared to this, a dead snail that is.Also, because of the high momentum, I doubt they'd have a viable "matter wave" property, they might be the most perfect mass we'd even come across. Looks like we're gonna see de-Broglie get out of his coffin tonight.
Is there a chance that the Hadron Collider could cause another 'Big Bang"?
No. The big bang contained all the energy and matter in the current universe. The stuff the LHC is throwing together is on the scale of atoms. You just don't have any stuff there, really. They are trying to recreate what happened just after the big bang to test models of physics that are currently untestable - such as string theory.
How massive do the protons accelerated at the LHC become according to relativity?
Their mass is a Lorentz invariant, which means it never changes. That’s what popularizers of physics call the “rest mass”; particle physicists don’t bother with the modifier.What you are asking for, really, is the particle’s total relativistic energy, [math]E = \sqrt{p^2 c^2 + m^2 c^4}[/math]. The LHC has recently been upgraded to (IIRC) 13 TeV. That’s roughly 13859 times the proton’s rest mass (expressed as an energy) of 938 MeV. So the Lorentz factor is [math]\gamma \equiv 1/\sqrt{1 - v^2/c^2} = 13859[/math]. If you like, you can figure out from that how close the velocity is to c. Pretty close, but not there.