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15
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1answer
6k views

Phase shifts in scattering theory

I have been studying scattering theory in Sakurai's quantum mechanics. The phase shift in scattering theory has been a major conceptual and computational stumbling block for me. How (if at all) does ...
7
votes
3answers
401 views

Is there Bremsstrahlung radiation for a charged massless particle?

This is a follow up question from: Massless charged particles Since by definition such a particle would interact with photons- resulting in some change in momentum- would the particle emit ...
5
votes
6answers
781 views

What needs to happen for one to ingest radioactive particles and how likely is this?

There are many stories about radioactivity and the relative danger of it in the news lately, but very little actual information. The radioactivity levels around Fukushima Daiichi are high, but seem ...
7
votes
3answers
368 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?
5
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1answer
1k views

Why does lambda decay violate parity?

When a lambda particle decays into proton and a pion, I am told it does not conserve parity. Why?
5
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2answers
6k views

How do alpha and beta particles ionise surrounding particles?

I've been wondering about this question for a while. If you have alpha and beta particles released from a radioactive core, how do they ionise surrounding particles?
7
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2answers
2k views

Why can't massless particle exceed speed of light?

Why massless particle can't exceed speed of light?
3
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4answers
169 views

is the Z boson one entity or are there as many entities as decay pairs, but they are equivalent and lumped together

just wondering if it is a distinction without a difference - it seeming a bit weird that one thing can decay into different things.
6
votes
1answer
329 views

Unusual particle effects at CERN

In 2010 there were press reports that CERN had identified unusual properties in particle behavour in collisions. One link here. Here is a partial quote: "In some sense, it's like the particles talk ...
3
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3answers
2k views

are particles “knots” or “kinks” of excitation in a field?

this is my mental picture for how they travel without a medium, how (like water waves) some can't stay still, why they have wave and particle properties, energy/mass equivalence, conservation, etc. ...