A model of the basic particles and forces featuring six quarks, three charged leptons, three massless neutral leptons and four fundamental force carrying bosons. The twelve fermions are arranged into three generations, while the bosons serve to explain the electromagnetic interaction plus the strong ...
6
votes
1answer
135 views
Why is SM+LQG usually not listed as a theory of everything
I have often seeen statements on physics.SE such as,
The only consistent theory of everything which we know of to date (2013) is string theory.
I don't quite see why? Adding the LQG Lagrangian ...
-4
votes
0answers
26 views
Similarity between Helmholtz solution and Flux tube meson
It seem there is a similarity between
and
Where does this similarity (in given photos) come from?
5
votes
4answers
283 views
Do strong and weak interactions have classical force fields as their limits?
Electromagnetic interaction has classical electromagnetism as its classical limit. Is it possible to similarly describe strong and weak interactions classically?
5
votes
0answers
88 views
How many orders of magnitude in energy spans the Standard Model phenomenological spectrum?
I am wondering if it makes sense to state that the upper limit is roughly 1012 eV (up to know the physics probed by the LHC seems to be pretty consistent with the SM) and the lower one is ... the ...
4
votes
1answer
128 views
Could electrons be a form of antimatter?
I've played with this idea for years, and haven't really been able to eliminate it. So, perhaps someone here can point to simple experimental evidence that would do so.
Here's the issue: Antimatter ...
0
votes
1answer
32 views
Are all (non-macroscopic, non-measurement) quantum mechanical interactions time-reversible?
I distinctly remember reading some article claiming some physicists had discovered a time-irreversible, subatomic quantum mechanical interaction. Is my memory just foggy or has this really been found?
...
1
vote
1answer
84 views
Usefulness of SUSY models when it cannot exist at any non-zero temperature
Unlike other symmetries (like electroweak symmetry), SUSY is spontaneously broken at any non-zero temperature due to some variation of the fact that the boundary conditions on bosons and fermions in ...
-3
votes
0answers
47 views
Ratio of masses of elementary particles in other bases? [closed]
One of the more annoying puzzles of the Standard Model is the seemingly arbitrary masses of the elementary particles. Is it possible that the ratios between the masses, for example that the tau weighs ...
4
votes
1answer
129 views
What if EM or QCD was spontaneously broken?
Suppose that Standard Model Higgs mechanism broke electromagnetism, by e.g. veving the charged component of the doublet, so that the photon was massive with $m_\gamma\sim v$. Could such a Universe ...
8
votes
0answers
103 views
Does the existence of Higgs imply the existence of Magnetic Monopoles?
I am aware that in theories with spontaneous symmetry breaking, Magnetic Monopoles can exist as topological solitons. Can the same be done with the Standard Model gauge group. I am familiar with the ...
1
vote
0answers
47 views
How the “Standard Model” get that name? [closed]
I want to know how the Standard Model theory got such "generic" name?
2
votes
1answer
82 views
How to find the Higgs coupling with a mixing matrix?
It is known that the couplings to the Higgs are proportional to the mass for fermions;
$$g_{hff}=\frac{M_f}{v}$$
where $v$ is the VEV of the Higgs field. I'm trying to figure out why this is true ...
9
votes
1answer
109 views
Is the fine-structure constant a parameter of the standard model?
According to the wikipedia entry on the fine-structure constant:
In fact, α is one of the about 20 empirical parameters in the Standard Model of particle physics, whose value is not determined ...
3
votes
0answers
56 views
Estimating the Kolmogorov Complexity of the Standard Model
The Kolmogorov complexity of a hypothesis / theory / model is the shortest computer program that simulates it, regardless of how inefficient executing that program may be in terms of memory and time. ...
4
votes
2answers
231 views
About free quarks and confinement
I simply know that a single free quark does not exist. What is the reason that we can not get a free quark?
If we can't get a free quark then what is single-top-quark?
-3
votes
2answers
243 views
why is dark matter the best theory available to explain missing mass problems?
Why is dark matter the best theory to explain the missing mass problem?
Why is dark matter mathematically necessary to explain the missing mass problem?
On a side not I believe dark matter is ...
1
vote
2answers
94 views
The status of $SU(3)_C$ symmetry in the Standard Model
In the Standard Model of Particle physics the $SU(2)_{EW}$ symmetry and the $SU(2)$ isospin symmetry are broken. What about $SU(3)_C$? Is it broken too?
if YES, what breaks the symmetry?
If NO, what ...
3
votes
0answers
58 views
List of cross sections?
Sometimes I need to look up a certain cross section, say the inclusive Z production cross section at $\sqrt{s}$ = 7 TeV. Is there a place where 'all the' cross sections are tabulated ...
8
votes
1answer
368 views
Do color-neutral gluons exist?
If I'm correct a quark can change color by emitting a gluon. For example a blue up quark $u_b$ can change into a red up quark by emitting a gluon:
$$u_b \longrightarrow u_r + g_{b\overline{r}}$$
...
5
votes
2answers
85 views
What constant varies in the fine structure constant?
Using the renormalization group approach, coupling constants are "running". If we apply this to the fine structure (coupling) constant, we do know that, e.g., at energies around the Z mass, $$\alpha ...
1
vote
2answers
260 views
Quark compositions in $\pi^+$ to $\pi^0$ pion decay
Pions can undergo a rare beta-like decay into leptons:
Pion beta decay (with probability of about $10^{−8}$) into a neutral
pion plus an electron and electron antineutrino (or for positive
...
9
votes
0answers
98 views
infrared free QED and Higgsless standard model phenomenology
This is one of those "what if" fantasy world type questions. I like hard sci-fi so please no "well, you changed one thing about the world so now anything goes." :)
What if the Higgs had no vev?
That ...
4
votes
2answers
287 views
What is the Standard Model equation which unified Strong, Weak, and Electromagnetism?
I always heard that three atomic force in small scale structure (Strong, weak and electromagnetic) are unified through the standard model, but I've never seen its unified equation. What is single ...
6
votes
1answer
165 views
A Game Of The Number Of Space-Time Dimensions
Holger Bech Nielsen, one of the founders of string theory, has apparently just played some sort of game between different potential dimensions for space-time and reached the conclusion that D4 wins in ...
6
votes
2answers
214 views
Is there an explanation for the 3:2:1 ratio between the electron, up and down quark electric charges?
I understand that the NNG formula relates $Q$, $I_3$, and $Y$ and can be derived in QCD; does this unambiguously predict the electric charge ratios without making assumptions about the definitions of ...
4
votes
3answers
136 views
How quark electric charge directly have been measured?
How quarks electric charge directly have been measured when quarks never directly observed in isolation? (Due to a phenomenon known as color confinement.)
1
vote
0answers
98 views
Mirror Matter Hypothesis?
What is the current state of the hypothesis of mirror matter today?
Are there any experimental data or theoretical arguments that exclude it by now, or is it still considered viable among physicists?
...
4
votes
1answer
40 views
Higgs VEV in terms of measurements on an ensemble?
Let $A$ be a Hermitian operator corresponding to some observable. If we prepare $N$ identical systems in the state $\psi$ and measure this observable in each system, the average of the measurements ...
0
votes
2answers
401 views
Can photons and gluons be holes in an aether?
Consider photons and gluons have 0 mass and 0 charge. In many respects they're already understood as the absence of a particle by mathematical models. Couldn't this be interpreted to mean they ...
3
votes
1answer
174 views
What breaks the symmetry between the electromagnetic and weak nuclear force?
I know the electromagnetic force is mediated by a photon and the weak nuclear force is mediated by two massive bosons. Are there any other insights into why the masses are so different?
2
votes
1answer
279 views
Is Connes model a composite Higgs in disguise?
Most of the 5-dimensional Higgs models can be seen, if I understand correctly, as models where the Higgs is a composite.
Now, is this true for Connes models? It is a model of extra dimensions too, ...
3
votes
2answers
130 views
Do any good theories exist on why the weak interaction is so profoundly chiral?
I find the profound asymmetry in the sensitivity of left and right chiral particles to be one of the most remarkable analytical observations captured in the Standard Model. Yet for some, I've not ...
1
vote
1answer
120 views
Does the Higgs mechanism address the spin statistics problem?
Since the Higgs mechanism is so intimately tied to binding together massless chiral fermions, does it happen to have anything to say about the spin statistics issue?
I'm actually assuming the answer ...
4
votes
2answers
308 views
Sparticles: Relationship to supersymmetry and dark matter?
I was attempting to read this paper after watching a show with Brian Greene. As I understand it, sparticles are a prediction of supersymetry, so I was wondering:
Wouldn't the discovery of ...
5
votes
2answers
119 views
Why is there a linear relationship between charge and isospin?
So the title basically says it all. Something that's really bothering me is the fact that the Gell-Mann Nishijima relationship can be extended to provide a linear relationship between charge and all ...
3
votes
1answer
153 views
Origin of electric charge
Baryons have charges that are the result of a polynomial calculation of their building blocks (quarks)'s fractional charges. But what gives these quarks electric charges? What interactions do they ...
5
votes
0answers
57 views
Does the Standard Model plasma develop a spontaneous magnetisation at finite temperature?
Reference: arXiv:1204.3604v1 [hep-ph] Long-range magnetic fields in the ground state of the Standard Model plasma.
Alexey Boyarsky, Oleg Ruchayskiy, Mikhail Shaposhnikov.
The authors of this paper ...
2
votes
0answers
32 views
Literature value of forward-backward asymmetry on the Z resonance?
I did a Standard Model calculation and I want to compare my answer to a measured value.
Does anyone know the literature value for the forward-backward asymmetry $\frac{\sigma_F - \sigma_B}{\sigma_F + ...
0
votes
0answers
110 views
Weak isospin and types of weak charge
My understanding is that QCD has three color charges that are conserved as a result of global SU(3) invariance. What about SU(2) weak? Does it have two types of charges? What I'm getting at is:
U(1) ...
8
votes
4answers
2k views
Why don’t photons interact with the Higgs field?
Why don’t photons interact with the Higgs field and hence remain massless?
5
votes
1answer
257 views
How do physicists know that mass of possible Higgs particle is limited between two values?
How do physicists know that mass of possible Higgs particle is limited between two values 90 GeV/c$^2$ and 145 GeV/c$^2$?
15
votes
3answers
548 views
Why is gravity so hard to unify with the other 3 fundamental forces?
Electricity and magnetism was unified in the 19th century, and unification of electromagnetism with the weak force followed suit, bringing into play the electroweak force.
I've been told that ...
2
votes
1answer
81 views
Is energy always proportional to frequency?
Google has no results found for "energy not proportional to frequency" and many results for E=hf. Is there an example of an energy that is not proportional to frequency?
4
votes
5answers
3k views
The Higgs field a new Luminiferous aether?
As of this writing it has been made clear to me that classical physics' Luminiferous aether was a terriblly poor discriptor of space. With the advent of Special Relativity and General Relativity, that ...
4
votes
0answers
105 views
Does the Standard Model have a Landau pole?
I have seen the statement that the Standard Model has a Landau pole, or at least it its believed that it does at $\sim 10^{34}$ GeV. Has this actually been proven (at least in perturbation theory, as ...
3
votes
3answers
77 views
Trilinear gauge couplings: Spin
In non-abelian gauge theories self interaction of gauge fields is permitted, allowing coupling such as $WWZ$ (i.e. $Z$-boson decaying to $W^+W^-$) or ggg (i.e. gluon splitting into two new gluons).
...
0
votes
0answers
64 views
Pareto efficiency and Standard Model parameters
Pareto Efficiency is a well understood concept in economics, which basically is a condition where no one actor could be made better off without some one being made worse off. This condition allows ...
1
vote
2answers
111 views
What is mass of free up and down Quark?
Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks ...
9
votes
1answer
287 views
The physics community's take on noncommutative geometry
Connes's noncommutative geometry program includes an approach to the Standard Model that employs a noncommutative extension of Riemannian metric. In recent years I've heard physicists say that this ...
5
votes
0answers
117 views
Are QFT solitons expected to represent standard model particles? Or strings?
Is work on solitons in QFT's focused on finding solutions that could represent the fundamental particles of the Standard Model, or is the work focused on finding particles Beyond The Standard Model? ...
