Tagged Questions
-1
votes
0answers
31 views
where do courses offered for quantum mechanics(for m.tech) in India [closed]
where do courses offered in M.tech for quantum mechanics in india ,tell me whether these courses offered in any of the IITs in india I am studying Electrical & Elctronics Engg. at present,I would ...
2
votes
1answer
56 views
Why is the total interaction cross section larger for incident particles with lower energy?
The cross section of a nuclear interaction is a measurement of the probability of that interaction occuring. These probabilities are typically presented in terms of barns ($10^{-28}$ m$^2$) as a ...
4
votes
2answers
120 views
nuclear fission and half life
Why is the alpha, beta or gamma decay of an unstable nucleus unaffected by the chemical situation of an atom, such as the nature of the molecule or solid in which it is bound? The chemical situation ...
4
votes
0answers
58 views
Can we excite a nucleus by means of very intense low energy gamma-photon irradiation?
The phenomenon of multiphoton ionisation of atoms has been studied, both theoretically and experimentally, for several decades. Intense LASER beam devices are the apparatuses used for the experimental ...
3
votes
4answers
232 views
How can the nucleus of an atom be in an excited state?
An example of the nucleus of an atom being in an excited state is the Hoyle State, which was a theory devised by the Astronomer Fred Hoyle to help describe the vast quantities of carbon-12 present in ...
4
votes
1answer
100 views
Why is the Wick contraction in HFB or BCS equal to a single-particle density?
I'm trying to understand how in Hartree-Fock-Bogoliubov
(HFB) or BCS theory we can write a product of creation/annihilation operators as single-particle densities under the guise of "Wick's theorem".
...
0
votes
1answer
79 views
Optimal methods for mapping out molecules, atoms and nuclei and their energy levels?
I'm wondering if it would be possible to map out all the different types of molecules, atoms and nuclei and their energy levels on one page (even if in a generalised way)? But perhaps I'm referring to ...
1
vote
1answer
97 views
About Efimov States and Halo-Nuclei
I read that
Halo nuclei could be seen as special Efimov states, depending on the subtle definitions. (The last sentence in the second to last paragraph of this Wikipedia article.)
This does ...
-1
votes
1answer
103 views
Direct nuclear reactions problems [closed]
can anyone explain Multi-step nuclear reactions in terms of direct nuclear reactions .
0
votes
1answer
89 views
Direct nuclear reaction in nuclear physics
Time taken to occur a direct nuclear reaction is very low $10^{-22}$sec . I want to know the Importance of direct nuclear reactions.
3
votes
0answers
203 views
Nuclear/quantum physics simulation software
Is there any software which is able to simulate D-T interaction for example and get temperature-crosssection curve without referencing to any experimental data?
Do we have quantum-level simulation ...
1
vote
2answers
169 views
Where does the “borrowed energy” come from in Alpha decay?
I was also thinking about the uncertainty principle in regards with energy & time. The question of something like:
Alpha tunneling out of the nucleus is where this can be invoked, but having an ...
4
votes
3answers
133 views
How do we know that internal conversion creates no intermediate photon?
I've read, from several sources, that in internal conversion -- an excited electron transferring its energy to another electron which is then emitted -- no intermediate gamma radiation is produced.
...
4
votes
1answer
515 views
Relationship between nuclear spin and nuclear magnetic moment?
We know that nuclear magnetic moment can be expressed in terms of the expected value for nuclear spin as:
$$\langle\mu\rangle =[g_lj+(g_s-g_l)\langle s_z\rangle]\frac{\mu_N}{\hbar}$$
(Cf. Krane), ...
13
votes
1answer
428 views
How come random matrices can predict energy spectra of heavy atoms?
Some of the applications of random matrices is to find the spectra of heavy atoms in nuclear physics which are usually difficult to find otherwise.
How can starting from randomness of some kind, ...
5
votes
2answers
698 views
Tunneling of alpha particles
Consider this explanation of the alpha decay: It says
The Coulomb barrier faced by an alpha
particle with this energy is about 26
MeV, so by classical physics it cannot
escape at all. ...
3
votes
0answers
1k views
Energy Levels of 3D Isotropic Harmonic Oscillator (Nuclear Shell Model)
One simple way of detailing the very basic structure of the nuclear shell model involves placing the nucleons in a 3D isotropic oscillator. It's easy to show that the energy eigenvalues are $E = ...
12
votes
4answers
5k views
Why do electrons occupy the space around nuclei, and not collide with them?
We all learn in grade school that electrons are negatively-charged particles that inhabit the space around the nucleus of an atom, that protons are positively-charged and are embedded within the ...
6
votes
3answers
257 views
References on the non-compositeness of the known elementary particles
What paper(s) or theory(s) describe or prove that the elementary particles that we have determined today cannot be made up of smaller more fundamental particles?
4
votes
0answers
344 views
Long time deviations from exponential decay in radioactivity
Are there any examples of common substances whose decay is not exponential?
We're used to thinking about radioactivity in terms of half-lives. This is a concept that makes sense only for a decay that ...
3
votes
1answer
687 views
Why must the deuteron wavefunction be antisymmetric?
Wikipedia article on deuterium says this:
The deuteron wavefunction must be
antisymmetric if the isospin
representation is used (since a proton
and a neutron are not identical
particles, ...
3
votes
1answer
631 views
Fermi's Golden Rule
It is well known that to calculate the probability of transition in the scattering processes, as a first approximation, we use the Fermi golden rule. This rule is obtained considering the initial ...
