Questions tagged [elementary-particles]

The fundamental subatomic particles that have no (currently known) substructure. These include fermions (quarks, leptons, antiquarks, and antileptons) and bosons (gauge bosons and the Higgs boson). A particle containing two or more elementary particles is a composite particle.

Filter by
Sorted by
Tagged with
2 votes
0 answers
74 views

Is it possible that there is a third class of fermions?

There exist six types of quarks, and six types of leptons, both divided in three generations. Could there be some other new class of exactly six particles, similar to these, but with properties such ...
user avatar
  • 21
0 votes
1 answer
16 views

(Solved) Why does this Kaon interaction need the intermediate up quarks?

In the answers to a set of practice questions my lecturer shows that we need these up and antiup quarks in the middle, but I don't quite understand why we can't go straight from the down to strange ...
user avatar
0 votes
4 answers
61 views

How can beta decay change elementary particles?

From what I read on beta minus decay, when it happens a neutron gets "converted" into a proton, an electron and an electron-antineutrino. I also read that both the neutron and the proton are ...
user avatar
  • 31
1 vote
2 answers
49 views

Extending Wigner's Classification with Gauge Symmetry

In Wigner's Classification, as far as I understand, one uses unitary irreps. of the Poincare group for treating an elementary particle, since then mass $m$ and helicity $h$ emerge naturally as ...
user avatar
1 vote
2 answers
84 views

Could a non-pointlike structure of elementary particles explain their spin?

Elementary particles are considered point-like. Which makes the concept of spin rather problematic. It can neatly be described by group theoretical considerations, but that offers no explanation what ...
user avatar
  • 1,653
1 vote
1 answer
32 views

Neutrino Oscillation and Probability

I am a fresher in a university pursuing physics major. I have been very passionate about neutrinos. So, I started studying them. But I have realised that, it requires a lot of mathematical physics ...
5 votes
2 answers
96 views

Can fundamental particles have magnetic/electric quadrupoles, octopoles, and higher-order moments?

Fundamental particles come with magnetic and electric charge, which makes the particles into a monopole source for the magnetic and electric fields. Of course, the magnetic charge is zero for all ...
user avatar
0 votes
2 answers
97 views

Is inertia present at the level of elementary particles?

Is a more massive elementary particle will experience more inertia in a one-on-one particle interaction?
user avatar
  • 41
2 votes
1 answer
74 views

Are there really random fluctuations of particles?

From classical physics, we know that particles are affected by thermal fluctuations. In turn, I wonder if there are any fluctuations of the particles that follow from QM and that are truly random. I ...
user avatar
  • 41
0 votes
1 answer
19 views

Cryogenic Particle Detectors

Recently, I started reading about Neutrinos, their types, oscillations and their detection. Today many experiments are being conducted to detect and measure oscillations of sterile neutrinos and anti-...
user avatar
-3 votes
1 answer
45 views

Could the equal amounts of positive and electric charge point to equal amounts of matter and anti-matter?

The universe is electrically neutral because the electric charges of all quarks and leptons cancel. If particles are electrically charged, then there are equal amounts of positive and negative ...
user avatar
  • 1,653
-1 votes
1 answer
113 views

Is leptons annihilation one process of 4 particles simultaneously or two independent processes of 3 particles? [duplicate]

Why leptons annihilation is not 4-particles, and it is represented in the form of two 3-particles? If the pair of an electron and a positron has formed a positronium particle, then what is virtual ...
user avatar
  • 29
2 votes
1 answer
95 views

What is a particle in QFT framework? [duplicate]

I've heard that in QFT a particle is a local excitation of a quantized field, but I can't understand how can I imagine this. For example in the second quantization of the Klein-Gordon field we get an ...
user avatar
2 votes
2 answers
73 views

Why do $Z$ or $H$ bosons can decay to a pair of quarks $t^+t^−$ with mass larger than boson in the inertial reference frame of boson?

The masses of $Z$ or $H$ bosons is less than the sum of the mass of two $t$ quarks. Why do $Z$ or $H$ bosons decay to a pair of quarks $t^+t^−$ with mass larger than boson in the inertial reference ...
user avatar
  • 29
0 votes
1 answer
60 views

How long can an unstable particle live? Is there a theoretical upper limit?

Somehow, in all my years of studying and reading, I have never come across an answer to this question.... Is there a fundamental limit to the lifetime of even the shortest-lived subatomic particles, ...
user avatar
  • 3,443
0 votes
1 answer
30 views

Is there data for natural background radiation measurement?

I am looking for raw data of alpha/beta/gamma particles natural background long-term measurement (preferably day by day or second by second for at least a few weeks), but cannot find any. I would be ...
user avatar
  • 39
0 votes
3 answers
103 views

Physical picture of electron spin?

Can the spin of an electron be understood as originating from an open string rotating around a perpendicular axis through its midpoint?
user avatar
1 vote
0 answers
50 views

Size of electron? [duplicate]

It is claimed that the electron has a size less than $10^{-19}$m. I presume this is based on high-energy scattering experiments. But isn’t this apparent size simply a function of the high energy of ...
user avatar
9 votes
2 answers
737 views

Do the mean lifetimes of short-lived particles follow a Gaussian (or 'normal', or 'standard') distribution? When plotted?

For instance, the average 'mean' lifetime of a muon is just over 2 microseconds.... If I plotted many, many muon lifetimes after careful experimentation, would the chart show a Gaussian distribution? ...
user avatar
  • 3,443
0 votes
1 answer
59 views

Why massive elementary particles come in different flavors?

Neutrinos come in 3 flavors: electron neutrino, muon neutrino, and tau neutrino. Quarks come in 6 flavors: up, down, top, bottom, strange and charm. And lets not forget electron, muons and taus too. ...
user avatar
  • 11.4k
1 vote
0 answers
28 views

Can you have a leading quartic gauge vertex in the standard model?

Under the standard model, is it possible to have a leading quartic gauge vertex in a reaction? For example, if I have a proton collider to look for the reaction $p\bar{p}\to q\bar{q}g$ (may not ...
user avatar
1 vote
1 answer
63 views

Standard Model Particle Properties

Basic question about the Standard Model: Is it accurate to say that all of the particles defined by the SM can be categorically distinguished entirely by discrete properties (eg, spin, color, charge ...
user avatar
  • 155
0 votes
0 answers
18 views

What is the Lorentz factor γ value in order to find the Larmor precesion frequency for the electron including the Thomas precesion correction?

I want to calculate the Thomas corrected value for the lab frame of the electron's Larmor precesion frequency using this equation: $$\omega_{s(g=2)}=\frac{e B}{m c \gamma}$$ I don't know what Lorentz ...
user avatar
  • 3,035
2 votes
1 answer
136 views

Does "lifetime of up quark" have a physical meaning?

I saw this question about the lifetime of an up quark. As far as I know, free quarks are never observed in experiments. Then what is the significance of a statement like "the lifetime of an up ...
user avatar
5 votes
4 answers
256 views

What particles are thought to have existed before Inflation?

What fundamental particles do most Grand Unified and Inflationary theories predict existed before the Inflationary period? Basically, what do we expect the family of particles existing during the ...
user avatar
2 votes
0 answers
38 views

Why is the hadronic $\tau$ branching ratio into 2 pions prefered?

In the PDG the $\tau$ branching ratios are listed and Br$(\tau^- \rightarrow \pi^-\pi^0 \nu_\tau)\approx 25$ %, while Br$(\tau^- \rightarrow \pi^-\nu_\tau)\approx 11$ %. How can this be since the ...
user avatar
2 votes
1 answer
92 views

If quarks are in fact made up of smaller particles, would we ever be able to find evidence for them? [closed]

Disclaimer: I'm not trying to suggest that quarks are made up of smaller particles. This is just a "What if?". We've had to infer the existence of quarks through the behavior of hadrons in ...
user avatar
  • 734
-1 votes
1 answer
140 views

Are Particles Necessary?

I started my reasoning from a curved spacetime: in the description of General Relativity, the universe is a continuum and we get to the Einstein Field Equations. Space and time may or not be ...
user avatar
  • 77
0 votes
0 answers
31 views

Have Preon models been ruled out? [duplicate]

Preons are hypothetical sub-components of quarks and leptons, however it looks to me they are not discussed much. Has some experiment proved they do not exist or are they simply not popular?
user avatar
0 votes
2 answers
113 views

The composition of electrons, quarks and gluons: something or nothing? [closed]

It is told that electrons, quarks and gluons are indivisible thus have no compositions like any particles. So, are they actually composed of nothing or space?
user avatar
  • 103
6 votes
2 answers
400 views

How can a particle without mass be useful?

person rather new to physics here, and I just started on a rather simple book on particle physics, but I was flustered to learn that there are particles without mass enforcing the fundamental forces (...
user avatar
1 vote
1 answer
49 views

What is the apostrophe I see in HEP articles? (NOT antiquark)

I keep seeing references to quarks as q, and antiquarks as qbar, but I'm also seeing things like q' and q'bar. I originally thought it was another form of notation for anti- but it doesn't appear like ...
user avatar
7 votes
3 answers
3k views

Do the quark types differ from each other in ways other than charge and mass?

I've read things online here and there that seemed to hint that there's more to quark type than mass and charge. Is this true? For clarity's sake, I'm not asking about properties individual quarks ...
user avatar
  • 734
6 votes
2 answers
651 views

Is it scientifically possible that “DNA can open wormholes” as suggested by an article in a mainstream & reputed journal?

I am attaching the links of two articles: Mathematic model for vibration behaviour analysis of DNA DNA Phantom Effect In the introduction section of the first article it mentions that Poponin tried ...
user avatar
1 vote
2 answers
174 views

What is the maximum spin of a particle? (Both theoretically and observed)

I know that the elementary fermions are spin 1/2 and the elementary bosons are spin 1 (except the potential graviton), but are what is the highest known spin of any elementary particle (including ...
user avatar
1 vote
2 answers
108 views

Why can't I assume the quarks inside a hadron move together?

Looking at the following Feynman diagram: Using conservation of energy, we can see that in the rest frame of $D^0$, the energy of $K^-$ is higher than its rest energy. Meaning, it is in motion. I ...
user avatar
0 votes
2 answers
186 views

Why isn't electron spin a real rotation? [closed]

When an electric current flows, a magnetic field is created. Then, isn't the magnetic field of a magnet also caused by an electric current?
user avatar
  • 121
1 vote
2 answers
201 views

Why isn't an electron a black hole? [duplicate]

My late night thoughts brought me to a question: If electrons are point particles, but have mass, why aren't they black holes?
user avatar
1 vote
2 answers
100 views

Do particle decays with different products have different decay rates?

https://en.wikipedia.org/wiki/Particle_decay#Probability_of_survival_and_particle_lifetime lists the mean lifetime of particles. But particles may decay in different ways, so is the mean lifetime the ...
user avatar
  • 257
6 votes
6 answers
738 views

Why does the electron not spin? [duplicate]

The goto answer to that question is that the electron is a pointlike particle and cannot spin. The electron is not pointlike though. It is described by a wavefunction. One can prepare the wavefunction ...
user avatar
  • 180
4 votes
6 answers
312 views

Scientific evidence of reductionism

There are claims that the standard model is a theory which explains almost all phenomenon that we see in the world. I am wondering what scientific evidence backs this claim? Specifically, there is a ...
user avatar
  • 231
0 votes
1 answer
77 views

Possible reactions / decays in the standard model

If we are in the Standard Model and we have the following processes: $$e^+ + e^- \to \mu + \mu^-\\ p + p \to K^+ + \Sigma^+ \\ p + n \to \Lambda^0 + \Sigma^+ \\ e^+ + e^- \to u + \tilde{t} $$ And ...
user avatar
  • 944
28 votes
8 answers
7k views

Why doesn't an electron rip itself apart?

A proton is stable because of the strong force between quarks, which is not there in electron. So what's the reason for electron's stability?
user avatar
0 votes
1 answer
314 views

What is time till false vacuum decay? (Which source is in error?)

https://arxiv.org/abs/1308.4686 says that the time till false vacuum collapse is just about the age of the universe: ΛCDM ... can be achieved if the top quark pole mass is approximately 178 GeV That ...
user avatar
  • 365
-2 votes
2 answers
104 views

Is the fact that elementary particles have uncorrelated masses a sign that they are not fundamental? [closed]

The masses of elementary particles in the Standard Model seem uncorrelated. They range from $0$ to $173.1\left(\dfrac{\mathrm{GeV}}{c^2}\right)$ without a functional dependence. In the Standard Model ...
user avatar
0 votes
1 answer
116 views

Could elementary particles have started as black holes? [duplicate]

If you calculate the Schwarzschild radius of an electron you get a value around $10^{-50}$, give or take a few orders of magnitude. Now, the electric field of a charged black hole can be felt outside ...
user avatar
4 votes
1 answer
619 views

Is the discovery of the Higgs boson tantamount to discovering the Higgs mechanism?

Is the discovery of the Higgs boson tantamount to discovering the Higgs mechanism? I mean, it's clear by now that the Higgs boson is there, but what about the Higgs mechanism? How can we ever be sure ...
user avatar
2 votes
2 answers
58 views

Does it make any difference if we switch particles to their antiparticle?

The title itself clarifies the crazy question. Does it make any difference if we switch particles to their antiparticle? By difference, I mean, Would everything alright with the laws of physics?
user avatar
0 votes
1 answer
24 views

Difference between two branches of $D^0$ decay

I'm trying to understand the following decays: i) $D^0 \rightarrow K^- + \pi^+$ ii) $D^0 \rightarrow K^+ + \pi^-$ The question came from Griffiths' "Introduction to Elementary Particles", ...
user avatar
0 votes
1 answer
10 views

Particle Energy Correlation with Probability Cloud

Is there a relationship between a particle’s momentum/energy and it’s wavelength? I know the Planck Equation for photon energy, but does this also apply to Leptons, Quarks and other Bosons?
user avatar

1
2 3 4 5
9