# Tagged Questions

The tag has no wiki summary.

424 views

### Do particle pairs avoid each other? Please end my musings

Can you explain what happens when a particle and its antiparticle are created. Do they whiz away from each other at the speed of light or what? I suppose that they don't because otherwise they would ...
172 views

### Can you tell if a particle is in superposition?

This may be an easy answer for anybody. Is it possible to detect if a particle A is still in a superposition via the sending a group of particles B through a box containing particle A?
218 views

### How can Sub-Atomic Particles be Visualized?

Can you see or accurately visualise sub atomic particles or are they known only by maths and/or inference?
263 views

### Temporal part of Quantum Wavefunction

I was hoping that someone could give me the more fundamental reason that we take as the temporal part of a quantum wavefunction the function $e^{-i\omega t}$ and not $e^{+i\omega t}$? Clearly ...
23k views

### How to deduce E=(3/2)kT?

It says in my course notes that a particle has so-called "kinetic energy" $E=\frac{3}{2}kT=\frac{1}{2}mv^²$ Where does this formula come from? What is k?
1k views

### What is the meaning of the word “particle” in particle physics?

I want to use Matt Strassler's definition of the word "particle" as a specific example: Matt Strassler writes: (1) "...all the elementary “particles” (i.e. quanta) of nature are quanta of waves ...
296 views

### Center Of Mass Troubles

I understand the concept of Center Of Mass(com), but I am having a difficult time interpreting the equation of the simplified case of one-dimension. The book I am reading defines the position of the ...
955 views

### Particles vs Waves

As I remember long ago, in my physics classes, I always had a great trouble understanding the concept of waves. Our professor used to explain, as if everything in this world is made up of waves. ...
213 views

### $sss$ decay and violation of strangeness

Why can the hyperon $\Omega^{-}$ not decay by strong interaction? It seems that strangeness must be violated, but why is it the only way?
437 views

### Why doesn't my particle simulation end in a flat disc?

I've made a 3d particle simulator where particles are attracted to each other by the inverse of the square radius. The purpose of my experiment is to see if this alone would create a flat disk (like ...
273 views

### Understanding a Physics Paper on Quantum Teleportation of Continuous variables

The paper I am trying to understand is here: http://pra.aps.org/abstract/PRA/v49/i2/p1473_1 The paper describes the quantum teleportation protocol in a general case with continuous dynamical ...
183 views

### Would synchronized dancing be a good way to describe entangled atoms to a laymen?

I was talking my professor about entanglement swapping between light and matter and it is briefly described here: You start out with a crystal capable of doing parametric down conversion of incoming ...
701 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 ...
560 views

### What was the first discovery of the delta baryon $\Delta^{++}$?

The delta baryons (also called delta resonances) are a family of subatomic hadron particles which have the symbols $\Delta^{++}$, $\Delta^{+}$, $\Delta^{0}$, and $\Delta^{−}$ and electric charges +2, ...
312 views

### Why are atoms particles?

The Oxford English Dictionary definition of particle is as follows: "A component of the physical world smaller than the atom." I read an article in NewScientist and it said "...all particles from ...
716 views

### The observation of a non-SM resonance at 38 MeV

Was reported here. Of course if this is real it is very exciting. It leads me to the question: given that it took so long to find this resonance at a meager 38 MeV, is it possible that all SUSY ...
847 views

### Why is it that protons and electrons have exactly the same but opposite charge? [duplicate]

Possible Duplicate: Why do electron and proton have the same but opposite electric charge? Doesn't it seem very curious that one is an elementary particle and the other a subatomic particle ...
97 views

### Is Joule heating only between charged particles?

The Wikipedia page for Joule heating explains "It is now known that Joule heating is caused by interactions between the moving particles that form the current (usually, but not always, electrons) and ...
211 views

### Photoelectric effect without light rays

For electromagnetic waves we have the photon association, one imagines light as particles "flying around". What is the analogy for a constant electrical field, one which doesn't change in time ...
681 views

### Existence of creation and annihilation operators

In a multiple particle Hilbert space (any space of any multi-particle system), is it sufficient to define creation and annihilation operators by their action (e.g. mapping an n-particle state to an ...
286 views

### Very basic question on spin

Can anyone give a simple explanation for what the fractions and integers mean in particle physics when describing spin? I've seen on another forum (the naked scientist) that it should not be thought ...
395 views

### Some very basic questions on the Higgs Boson

What exactly is a boson? Is the Higgs boson the cause of gravity or a result of it? Does the collision of particles at the LHC create a gravity field or waves or somehow interact with the gravity ...
335 views

### Is particle number a problem for formulating statistical physics in a mathematically rigorous manner?

Quantities like the chemical potential can be expressed as something like $$\mu=-T\left(\tfrac{\partial S}{\partial N}\right)_{E,V}.$$ Now the entropy is the log some volume, which depends on the ...
1k views

### What entities create a gravitational field?

It is well known that masses create a gravitational field. Photons are affected by gravitation, but do they generate a gravitational field as well? What about the other gauge bosons? Do gravitons ...
104 views

### The Large Hadron Collider produce material residues?

In the LHC particles are accelerated until they collide, producing energy and this make new particles. My question is what happened after this. What happened to new particles and to old particles ...
559 views

### Can every particle be regarded as being a combination of Black holes and White holes?

Can the statement be regarded as true? That every particle, or element in the universe can be regarded as a combination of black hole and white hole in variable proportion.
2k views

### How can/does calculus describe the movement of a particle?

I was talking to Roger Penrose about calculus in the appendix in his book Cycles Of Time and he said I'd need a good understanding of calculus if I wanted to read his book in great depth. He said I ...
332 views

### Higgs boson and quasiparticles

Do we know exactly the difference between particles and quasiparticles? Is Higgs boson a particle or a quasiparticle? I ask this because if I understood well, Higgs boson created by a spontaneaous ...
357 views

### How can particles being closed strings in String Theory create solidity in objects?

I understand how particles with certain masses can form to make atoms, which create solidity in objects due to Pauli's Exclusion Principle and what have you. These particles actually have mass and to ...
230 views

### what interactions would take place between a free proton and a dipolariton?

What interactions can be expected to take place between a free proton and a dipolariton, (a) at high energies and (b) at lower energies? A dipolariton is a bosonic quasi-particle mentioned in a ...
283 views

### A question regarding particle trajectories in the symplectic manifold formalism

How to solve a free particle on a 2-sphere using symplectic manifold formalism of classical mechanics ? Is there a way to get coriolis effect directly, without going into Newton mechanics? And is ...
913 views

### Questions on wave-particle duality

Wave-particle duality states that a particle has both wave properties and particle properties when one is not observing it. 1) What is an observer? Need it be anything living or can other particles ...
330 views

### How the nucleon structure has been identified experimentally?

It is known that nucleons (proton, neutron) are composed of partons (quarks, etc.). How was this identified experimentally? In particular, how it has been identified that nucleons comprise of more ...
2k views

### Are elementary particles actually more elementary than quasiparticles?

Quarks and leptons are considered elementary particles, while phonons, holes, and solitons are quasiparticles. In light of emergent phenomena, such as fractionally charged particles in fractional ...
1k views

### Do particles and anti-particles attract each other?

Do particles and anti-particles attract each other? From the very basic understanding that they are created out of nothing mutually and collide to annihilate each other seems to indicate this happens ...
264 views

### Stability of neutron [duplicate]

Possible Duplicate: How come neutrons in a nucleus don't decay? It is known that free neutron decays in 15 minutes on average. Why is it much more stable when "placed" in nuclei? Edit: ...
1k views

### why is there no ninth gluon?

A teacher of mine told me once that there were no ninth gluon because such a one should be white and interact infinitely far, and no one has been observed. Is there also a theoretical reason?
34 views

### GUT predictions for charm mass?

Most GUT models have some relationship between down-type quarks and leptons, that more or less agree with the observed values after running the renormalization equations. But, what about up-type ...
214 views

### Speed Distribution of The Particles

I want to know the distribution of the particles's speed. The particles what I mean are nucleons and electrons of element. Consume there is 1kg of iron on room temperature and it's shape is sphere. ...
4k views

### Speed of a particle in quantum mechanics: phase velocity vs. group velocity

Given that one usually defines two different velocities for a wave, these being the phase velocity and the group velocity, I was asking their meaning for the associated particle in quantum mechanics. ...
2k views

### Why does Davisson-Germer experiment confirm electron's wave-particle duality?

First I apologize if my question is trivial and for my poor English. I was wondering why my teacher states that "electron's wave-particle duality is verified if we observe diffraction of the electron ...
842 views

### Does the speed of sand flow in a hourglass depend on a height of a sand column above the hourglass neck?

In a hourglass, does the sand flow through the neck depend on the amount of sand in the upper glass? If we consider a sand flow analogous to fluid flow, then it should depend linearly, but in that ...
850 views

### What is the “shape” of atomic/subatomic particles?

I apologize in advance for my ignorance if this is a question with an obvious answer... I am not experienced in this field. But are such particles in the universe points with a charge, or are they ...
177 views

### What is a proton-rich atom?

http://wiki.chemprime.chemeddl.org/images/e/e4/Plot_of_Neutron_Number_vs._Proton_Number_.jpg The above graph shows that all elements have more neutrons than protons in this nucleus. So how is there ...
236 views

### Transition of Electric Charge In Collision Between Proton And Antiproton

I know that $$p+\bar{p}\to 4\pi^++4\pi^-+(\gamma)$$ Before the collision, the sum of absolute electric charge value is $2$. $$\left | +1 \right |+\left | -1 \right |=2$$ After the collision, the ...
2k views

### How Did Paul Dirac Predict The Existence of Antiproton?

The existence of the antiproton with -1 electric charge, opposite to the +1 electric charge of the proton, was predicted by Paul Dirac in his 1933 Nobel Prize lecture. Quotation by Wikipedia. ...
1k views

### Confusion between the de Broglie wavelength of a particle and wave packets

So I learned that the de Broglie wavelength of a particle, $\lambda = \frac{h}{p}$, where h is Planck's constant and p is the momentum of the particle. I also learned that a quantum mechanics ...
1k views

### Good book about elementary particles for high school students?

I need a good book about elementary particles. I am a high school student and don't want anything to technical. I read a brief history of time and the universe in a nutshell but i want something that ...
Can spin of a particle or a group of particles become infinity? Explain plz. Is there any representation for spins like dot(for $S=0$) and arrow (for $S=1$)? If so what for $S= \infty$?