How do having no mass or charge affect structure?

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Discussion Overview

The discussion revolves around the properties and implications of neutrinos, particularly the electron neutrino, in relation to mass, charge, and their structural characteristics within the quantum realm. Participants explore theoretical aspects, the nature of elementary particles, and the relationship between mass and dimension.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants question whether the electron neutrino, having no mass or charge, implies it has no dimensions or if it can possess dimensions despite its lack of mass.
  • It is proposed that neutrinos are pointlike and lack internal structure, suggesting they are elementary particles with dimensions smaller than measurable scales.
  • Some argue that the absence of mass and charge might indicate a more fundamental nature compared to particles that possess mass and charge.
  • Participants discuss the relationship between mass and dimension, noting that in quantum mechanics, these concepts may not be intrinsically related as they are in classical mechanics.
  • There is a mention that the current understanding of the electron neutrino's mass is not settled, with some asserting it has a non-zero mass based on experimental data.
  • Some participants express confusion regarding the role of the Higgs boson in determining particle mass, with discussions highlighting that the Higgs mechanism does not predict masses but allows for them based on coupling values.
  • Questions arise about the structure of sub-atomic particles and the fundamental basis for their charges, with some suggesting that understanding structure could be key to understanding charge origins.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the properties of neutrinos, the implications of mass and charge, and the role of the Higgs boson. The discussion remains unresolved on several points, particularly concerning the nature of neutrinos and the relationship between mass, charge, and structure.

Contextual Notes

Some statements reflect uncertainties about the current theoretical understanding of neutrinos and the Higgs mechanism, with limitations noted in the clarity of definitions and the implications of mass and charge in quantum mechanics.

variable1
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I am curious to know if anyone can shed some light on a question I have concerning the neutrino. I am referring only to the electron neutrino and not the others that have theoretical mass values. If it has not mass or charge does that mean it has no dimensions? Or because it has no mass can it have any dimension? Is there any theory on the structure or physical properties of quontum particles? I ask because I am trying to understand some fundamental structural qualities in the quantum world. Thanks in advance for your insight.
 
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I should spell check before submiting...
 
The neutrino, as any other elementary particle (it's not important if they have or not a mass different from zero) is pointlike. This statement is to be read in the following sense: as far as we know right now the neutrino has no internal structure (it's an elementary particle), it means that it isn't composed of any king of "subparticle". In our understanding an elementary particle has no dimension, they are like points, that means just that they dimensions are smaller than any mesure we can realize right now.
 
Also there is presently no reason to suppose that the mass of the electron neutrino is zero.
 
That makes sense on a basic level. I understand also that the physical dimensions given to the larger particles is based on the motion of quarks. It seems to me that an object with no mass and no charge we might conclude it is more fundamental than a particle with mass and charge? Its kind of like trying to understand the mechanics of a black hole. If an object can be infinitely small why can't it also be infinitely large? Again I am just trying to rap my head around the concept of no charge or mass. Seems to me if it exists and we can measure it or detect it then whe should be interested in its structure. Assuming neutrinos have in fact been detected.
 
Bill_K said:
Also there is presently no reason to suppose that the mass of the electron neutrino is zero.

Right. I am only referring to the current theory about those values. Is the current value assigned to the electron neutrino such because it is so poorly understood?
 
As I have understood, your difficulties are related to the fact that neutrinos havo no mass and no charge. But this is not a limitation. For example electrons have both mass and charge but they are pointlike too. The importat concept is that there is no such thing as poinlike objects in nature. When we say that an object is pointlike we are talking about a mathematical description, but in nature it is just something whose dimension we are not able to mesure yet because they are very very small.
It can happen for both massless or massive particle, or for both charged or chargeless particles (consider also that electric charge is not the only charge in nature).
The concept of mass is a concept completely unrelated to the concept of dimension.
 
Got it... Thanks again for helping. I totally get that mass and dimension are different concepts and in classical mechanics they have a vital relationship. So in quantum mechanics then, I am guessing, The two concepts are not related in such an intrinsic fasion?
 
variable1 said:
Right. I am only referring to the current theory about those values. Is the current value assigned to the electron neutrino such because it is so poorly understood?
Neutrinos are understood quite well, actually. We have a theory that says that electron neutrino has non zero mass. Experimental data place upper bound on the mass (according to Wikipedia it's 2.2 eV which is freakishly low).
 
  • #10
Dead Boss said:
Neutrinos are understood quite well, actually. We have a theory that says that electron neutrino has non zero mass. Experimental data place upper bound on the mass (according to Wikipedia it's 2.2 eV which is freakishly low).

There in is my missunderstanding... I was looking at a chart for sub-atomic particles and it labeled the charge and mass as zero. I looked up your reference and did see the >2.2 eV reference... Thanks
 
  • #11


variable1 said:
I should spell check before submiting...

I think you meant "submitting" ... :-p
 
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  • #12
Given that the Higg's boson has been confirmed, shouldn't we be able to predict the theoretical mass of a neutrino?
 
  • #13
No, the mass is put in by hand. It is the value of the coupling of the neutrino to the Higgs. The Higgs mechanism does not give a prediction for Standard Model masses.
 
  • #14
Yes... I am sure that given how recent Higgs has been potentially discovered there are several efforts underway to reconsile a lot of unknowns to include the mass of the neutrino.

Being that my original post had to do with structure are there any theories about the actual structure of sub-atomic particles? I am interested in the basis for charges. I understand that we know particles come in the 3 basic charges but why do they have said charge? It is my opinion that structure would play a key roll in the nature and source of those charges. Or is it a matter of it is what it is and we leave it at that?
 
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  • #15
kloptok said:
No, the mass is put in by hand. It is the value of the coupling of the neutrino to the Higgs. The Higgs mechanism does not give a prediction for Standard Model masses.

Wait.. What? I thought the Higgs was the source of mass in matter?
 
  • #16
Where is the 'spell check icon'...I have nver found it...as you can tell
 
  • #17
variable1 said:
Wait.. What? I thought the Higgs was the source of mass in matter?

The following quote from forum user Bill_K should answer your question (from this thread):

Bill_K said:
The Higgs particle only relates to the rest mass of certain elementary particles, not mass in general. Composite particles like the proton for example, would still have mass even if the Higgs did not exist.

Furthermore, even for those particles, the Higgs does not explain why they have mass. It only permits them to. I hope you see the difference! Electrons, muons, quarks couple to the Higgs field, and the strength of their coupling determines their mass. But no one understands why the coupling exists, or why the various masses have the particular values they do. Some future theory will have to answer these questions.
 
  • #18
Ah... ok. That does make sense. But as I read some of the other Higgs posts I understood the Higgs mechanism ie the particle and the field, is fundamental to all sub-atomic particles and it is this mechanism that explains why particles have mass. It was only a theory without proof before its likely discovery here in the last few days. I was under the impression that the Higgs mechanism is what was being used to explain why particles have mass. Correct me if I am wrong.. Which I probably am.. Thanks again for the help in understanding this issue.
 

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