25
votes
5answers
3k views

Do electrons have shape?

According to the Wikipedia page on the electron: The electron has no known substructure. Hence, it is defined or assumed to be a point particle with a point charge and no spatial extent. Does ...
3
votes
1answer
168 views

Rigorous mathematical formalism of particle physics

Can anyone provide me with a rigorous mathematical definition of the fundamental particles (all fundamental bosons and fermions), reflecting the analogy of action of groups with interaction of ...
-9
votes
2answers
193 views

Which is the heaviest elementary particle? [closed]

Which elementary particle has the greatest rest mass? (For the sake of this question I'll call a photon's rest mass 0, whether it is or isn't (actually, tell me if this is the right thing to do)).
1
vote
0answers
62 views

Fundamental difference between neutron and proton

As I try to understand the elementary particles,I was reading strong interactions and Isospin from a book.Then I came across this: Thus,the strong interactions do not distinguish between a proton ...
0
votes
0answers
63 views

What is the most fundamental peice of matter? What is it that thing which can no more be sub-divided?

I know that there is theory that strings are the most fundamental particles. But if it is a string, then it can be 'cut' into pieces, and if it can be 'cut', then it can be cut at infinitely many ...
-1
votes
2answers
85 views

Are particles solid?

My intuitive understanding is that although atoms are mostly empty space, the nucleus is solid. Thus a neutron or a neutrino can collide with it and do things like deflect or cause a nuclear ...
2
votes
1answer
111 views

What is the difference between QFT and elementary particle physics?

I'm a little unclear as to how QFT differs from Elementary particle physics. They both use pictorials of Feynman graphs, is it that Elementary particle physics assumes the point particle perspective, ...
1
vote
1answer
106 views

Elementary particles

That's what Wikipedia says about Elementary Particle: In particle physics, an elementary particle or fundamental particle is a particle whose substructure is unknown, thus it is not known to be ...
1
vote
2answers
98 views

Can we make usable energy from subnuclear particles?

I understand mass and energy are the same, but in this question I will be talking about mass being turned into usable energy (electricity/heat/etc). We can make our energy through chemical reactions ...
1
vote
5answers
188 views

Do the particles made in a collider exist outside the collider?

Below is the transcript of a section from Demystifying the Higgs Boson with Leonard Susskind. Around 1:02:23 Susskind says that the heaviest of the fermions is called the top quark. Top quark is ...
12
votes
3answers
288 views

Why are all force particles bosons?

All of the force-particles in the standard model are bosons, now my question is pretty short, namely: Why are all force particles bosons? This can't be a coincidence.
3
votes
1answer
42 views

Asymmetry in muon energies of public CMS dimuon event data

CMS published for educational purposes (caveat) 100.000 dimuon events: https://cms-docdb.cern.ch/cgi-bin/PublicDocDB//ShowDocument?docid=11583 As one easily sees, column 4 shows the first muon's ...
8
votes
2answers
455 views

Is everything made of massless particles?

Photons have no mass. Yet they interact gravitationally, as all energy does, with other energetic and massive particles. This means that if you put multiple photons in a system, you get something that ...
0
votes
0answers
103 views

History of the elementary particles

The current model for the elementary particles is the standard model. I understand its basics It is for me however, difficult to wrap my mind around it without having some kind of knowledge of the ...
3
votes
1answer
320 views

Why no fundamental force from the Higgs? [duplicate]

I wish to ask whether I understand the following correctly. This universe seems to have six fundamental elementary bosons namely photon $(\gamma),\ W$-bosons$(W^+,W^-),$ gluon$(g),\ Z$-boson $(Z)$, ...
0
votes
1answer
109 views

Is everything in the physical world composite?

In philosophy there is a principle that anything composite cannot have existed eternally, since it is preceded by its parts and whatever forces assembled it. Is everything in the physical world ...
1
vote
0answers
101 views

Matrix element approximation

In the formula for the decay width of $\Upsilon(4S)$ to B-mesons from $\text{e}^+\text{e}^-$ collisions: $$\Gamma_{\Upsilon(4S)\to B\bar{B}}=\frac{\left|\underline{P}_B \right|}{8\pi ...
2
votes
0answers
110 views

Parton Distribution Functions, average cross section of the nucleon

Say we are given the scattering cross section for neutrinos from $d$ and $\bar{u}$ quarks as $\frac{d\sigma^{d}}{dQ^2}=\frac{G_F^2}{\pi}$, $\frac{d\sigma^{\bar{u}}}{dQ^2}=\frac{G_F^2}{\pi} (1-y)^2$, ...
3
votes
0answers
63 views

Can the mass of a SUSY particle depend on the process it participates in?

I believe that mass is property of every particle,as well as spin etc.Now I'm interested in SUSY particles in cMSSM model.Can it be,that mass of a SUSY particle (at one point in five parameter space) ...
3
votes
2answers
498 views

Why do physicists think that the electron is an elementary particle?

When we first discovered the proton and neutron, I'm sure scientists didn't think that it was made up of quark arrangements, but then we figured they could be and experiments proved that they were. ...
1
vote
1answer
494 views

Definition of elementary particle [duplicate]

Possible Duplicate: Why are atoms particles? According to wikipedia an elementary particle or fundamental particle is a particle not known to have substructure. Moreover, I've learned ...
1
vote
2answers
406 views

A basic confusion about what is an atom

Wikipedia defines atom as The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. and defines electron as: The ...