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Feb2313 08:41 AM
ZapperZ

1 
21,126 
God particle is 'found': Scientists at Cern expected to announce on Wednesday Higgs boson particle has been discovered...

Jul1112 01:13 AM
tom.stoer

178 
34,706 
Hi everyone,
I have studied QFT, the SM and the Higgs mechanism when I was in university and after reading an...

T 05:03 PM
Jochent

3 
129 
Hi all,
I think that the off shell decay dosn't decrease the decay cross section, I mean if a particle X
decays...

T 01:31 PM
mfb

1 
178 

 
 
 
Hi everyone. I'm studying Heavy Quark Effective Theory and I have some problems in proving an equality. I'm am...

Y 06:01 PM
Hepth

7 
282 
All nuclei with A > 210 are alpha emitters, yet very few emit protons spontaneously.
Yet both decays lower the...

Apr2214 06:52 PM
mathman

2 
309 
Hi all,
I am currently trying to calculate the beta function for scalar QCD theory (one loop for general su(n)).
...

Apr2214 03:07 PM
The_Duck

1 
198 
Here's an example of the graphs I am currently studying.
...

Apr2214 02:53 AM
snorkack

2 
292 
Starting from the Lagrangian density:
L= \frac{1}{4}F_{\mu\nu}F^{\mu\nu} + \frac{m^{2}}{2} B_{\mu}B^{\mu}
we can...

Apr2114 08:03 AM
ChrisVer

1 
308 
Ive attached the R ratio formula to this post, please could someone who is familiar with it tell me what Nc is?
...

Apr2014 04:19 PM
mfb

5 
247 
What are the lowest energy transmutation caused by a neutrino and an antineutrino respectively?

Apr1914 09:00 AM
Vanadium 50

7 
328 
Is there something like a "neutrino spectrum"?.
Would it be analog to light spectrum?.
Sorry for the ignorance, just...

Apr1814 07:58 PM
kurros

3 
331 
Hi,
I am just learning some materials and struggling to find what the other octet is. I know the following:
3...

Apr1814 09:37 AM
Bill_K

1 
317 
All the Feynman diagrams I have seen so far for a neutron colliding with a neutrino have a w+ with an arrow from the...

Apr1814 09:26 AM
mfb

3 
332 
So I'm trying to show that one choice of representation for the SuSy generators fulfills the SuSy algebra.... (one of...

Apr1814 07:11 AM
andrien

4 
354 
What is the Decay Width of a particle and how is it related to the particle's lifetime ?

Apr1814 06:19 AM
UltrafastPED

1 
240 
Hi folks  does anyone know of a proof that particle (quanta) number in QFT is / is not Lorentz invariant? I'd be...

Apr1714 03:53 PM
Mordred

20 
664 
I know that fermions and bosons can thermodynamics can be calculated via the Fermidirac or Bose_Einstein...

Apr1714 01:54 PM
Mordred

4 
312 
i've looked online and the closest i've found to a definition is this:
what does this mean? i understand that...

Apr1714 07:21 AM
rwooduk

3 
359 
This is related to a homework problem but I want to understand it as well. How can a proton break up into a positron...

Apr1614 11:14 AM
metamathphys

3 
429 
Hi all,
I'd like to know how the chiral symmetry protect the electron mass in the oneloop calculation of the...

Apr1614 10:09 AM
andrien

1 
309 
Hi Folks,
We use a UV bulb in my workplace which contains deuterium gas. The bulb is safely contained within a...

Apr1514 06:04 PM
teaforone

4 
350 
Hi folks,
I've been reading about MontonenOlive duality and understand that two different classical theories can...

Apr1514 03:52 PM
metroplex021

0 
277 
Consider
e+e* > q+q* in the centre of mass frame. Where I am using star for antiparticle.
the quark and anti...

Apr1514 07:11 AM
RGevo

9 
489 
I'm looking at charmonium and its decays. Given a list of data on the charmonium states I'm asked to say why ψ'' has...

Apr1414 07:20 AM
Einj

2 
361 
Hi all,
I have a couple questions about radiation from radioactive elements. I've read a lot of articles on the...

Apr1314 10:46 PM
Simon Bridge

9 
458 
Hi.
This may be a trivial question, but I'm unable to find a definitve answer.
How is the mass on a atomic...

Apr1214 06:01 PM
bcrowell

4 
367 
Why are exited states of an Isotope metastable? Is it because they have a large spin and therefore the final states...

Apr1214 10:00 AM
mfb

4 
465 
I came across a worked example question in a particle physics book this morning that had a beam of neutrinos of energy...

Apr1214 03:34 AM
Naz93

3 
412 
So i have a question regarding a homework question i'm working on which suggest a neutral pion travelling with...

Apr1114 05:55 PM
mfb

2 
328 
I read this on a website called Physics for Idiots
"If an electron gets near another electron it emits a virtual...

Apr1114 04:06 PM
mfb

6 
594 
Hi everyone. I have been studying CP violation in kaon systems. I would like to know is someone can explain why, to...

Apr1114 02:16 PM
Einj

6 
385 
I am trying to derive the conserved charge from the symmetry of the action under Lorentz transformations, but I am...

Apr1114 02:04 PM
samalkhaiat

5 
386 
I'm learning about particle physics at the moment, and have read that the J=3/2 multiplet contains baryons comprised...

Apr1014 01:50 PM
Naz93

3 
396 
In SM, people say the ##SU(2)\otimes U(1)## theory unify the EM and weak interaction. I understand that the two...

Apr1014 12:35 PM
clem

2 
377 
I don't completely understand why an electron positron pair cannot be created from an isolated photon. I understand it...

Apr1014 07:59 AM
ofirg

10 
422 
Hi, I'm in the process of revision for upcoming exams, one likely question will give a number of decays (~5) and ask...

Apr1014 06:37 AM
rwooduk

6 
385 
1) Since Wigner it is well known that for massless particles of spin s the physical states are labelled by helicity h...

Apr914 10:37 PM
strangerep

67 
5,560 
How can we determine the ranges of strong interactions and weak interactions?
Can calculations of relevant scattering...

Apr914 09:36 PM
Simon Bridge

4 
379 
Hi. I was reading Griffiths page 289 and I wasn't sure how the transition from Eq. (8.45) to (8.46) was allowed. What...

Apr914 07:20 PM
spookyfish

2 
334 
Why is the chiral symmetry breakdown determined for the vector/axial current as:
V =...

Apr914 05:07 PM
The_Duck

1 
335 