Questions tagged [elementary-particles]

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Why do physicists say that elementary particles are point particles?

For example, an electron, it has mass and charge, but is considered to have point mass and point charge, but why? Why are they assumed to have charge and mass in a single infinitely small point in ...
7
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1answer
508 views

What are fundamental dimensions used to describe the physical universe? [closed]

I have heard that the universe can be explained in terms of the four fundamental forces. I have also heard it can be explained in terms such as space, time, energy, mass or even motion. To further ...
3
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1answer
971 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 $(Z)$, ...
2
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2answers
197 views

Why is boson spin number related to attraction and repulsion?

The accepted answer to this question says Since the electroweak interaction is mediated by spin 1 bosons, it is the case that "like (charge) repels like and opposites attract". Another answer ...
1
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2answers
112 views

Quarks are now considered to be fundamentals, but so were atoms some time ago. So the way we see is only limited by our technological advances? [duplicate]

After watching this FuseSchool - Global Education episode, I cannot stop thinking how can something not have a substructure, how it cannot be split? http://www.youtube.com/watch?v=nlv06lSAC7c
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1answer
80 views

Which are the obstructions for $E_8^L\times E_8^R$ unification?

After left-right symmetry extension of the standard model, $$G' \times SU(2)^L \times SU(2)^R$$ it would seem that a logical pathway to grand unification is to try to obtain it by breaking down from ...
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0answers
119 views

Are we able to store low energy positrons in a magnetic field for arbitrarily long time?

And if not, what prevents us? Is there a mathematical equation describing the loss rate?
2
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1answer
571 views

Which of the properties of particles are intrinsic properties and why? [closed]

For macroscopic objects it's clear that - once observed - the observed property does exist for a while, even if we are no longer observing it. That has to do with the complexity and stability of such ...
2
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3answers
3k views

What is the smallest observable structure in the universe?

I've been wondering about the Planck length recently, but it is not observable. What is the smallest actually observable structure in the universe?
2
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1answer
97 views

What is compositeness at energy scale $\Lambda$?

I am a high school student taking a modern physics course. I am reading the 1983 journal article New Tests for Quark and Lepton Substructure which covers some science and mathematics behind quark and ...
2
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1answer
891 views

Strangeness of elementary particles

What is the property, whose violation led to the assumption of strangeness? Prior to the discovery of strangeness was it assumed that particles that are produced by strong interactions can decay only ...
2
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2answers
293 views

Angle in pair production

Assuming a very high energy photon (energy $E$) crosses the atmosphere and produces an electron-positron pair, I would like to know what is the angle between these to leptons produced. I was trying to ...
2
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1answer
311 views

Decay, scattering and forces in quantum field theory

In quantum field theory, the concept of a force is not explicitly present, and we speak of interactions. I guess we could say that a force is an emergent phenomenon. Interactions manifest themselves ...
1
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1answer
233 views

Physics of K meson

$K^{0}$ meson consists of a $d$ quark and an $\bar{s}$ antiquark. Its antiparticle $\bar{K^{0}}$ consists of an $s$ quark and a $d$ antidown quark. $$|K^{0}\rangle=|d\bar{s}\rangle$$ $$|\bar{K}^{0}\...
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0answers
108 views

Why don't strings have a Planck mass?

I understand that strings have a size of roughly the Planck length $l_P$ of $10^{-35}$ m. If that is the case then one would expect that their mass would be roughly the Planck mass which is an ...
1
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1answer
70 views

Strong gravity at the micro level?

I have read this: https://resonance.is/black-holes-elementary-particles-revisiting-pioneering-investigation-particles-may-micro-black-holes/ where it says: For the case of hadrons, it is at least ...
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2answers
130 views

What is the reason for a wide B$_S$ peak in dimuon plot?

Why is the B$_s$ meson peak in dimuon invariant mass spectrum wider than the others? Upsilon meson has a lifetime of several orders of magnitude shorter, which by my intution should lead the wider ...
0
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1answer
41 views

How do electrons absorb and reflect photons 100% of the times if their existence is based on probabilities in the density cloud? [closed]

Shouldnt there be observations where we never see the color of an object because none of their electrons existed in the space where photons would hit them ? Or does this not happen because of how many ...
0
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1answer
819 views

Particle Detector: dE/dX and momentum resolution

I'm reading an article describing a particle detector. I did not understand the following things in it. "The drift chamber (of this detector) was described as having a dE/dX resolution that is better ...
0
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2answers
113 views

Since nucleons are not elementary particles more, how we call nucleons and electrons together now? [closed]

In the time before the discovery of quarks the nucleon particle proton and neutron together with electrons were called elementary particles. It's a little bit boring to have only the possibility to ...
0
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2answers
1k views

What does temperature look like at the subatomic level?

I am trying to get a better understanding of the definition of temperature at the subatomic level. I have a background in molecular biology with some college physics, but no deep quantum mechanics ...
-1
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2answers
910 views

How can a truly elementary particle change into other particles? [duplicate]

Consider for example the next changess: The change of a Higgs and the change of a muon [in the diagram of which we also see the decay of (virtual) $W^-$ into an electron and its associated neutrino)]....
-1
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1answer
131 views

What is a subatomic particle? [closed]

I am curious as to what a subatomic particle is and have done a bit of research but have turned up with nothing of any help.