Gravity and the standard model

Click For Summary

Discussion Overview

The discussion revolves around the relationship between gravity and the standard model of particle physics, particularly focusing on the implications of massless particles in gravitational fields and the role of the Higgs boson in mass generation. Participants explore theoretical models, the integration of gravity into the standard model, and the challenges of quantizing fields.

Discussion Character

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

Main Points Raised

  • Some participants argue that the standard model does not adequately account for massless particles like photons in a gravitational field, questioning its completeness.
  • Others suggest that gravity's influence at the subatomic level may not be significant enough to require its inclusion in all theoretical models.
  • There is a viewpoint that the uncertainty in predicting the masses of particles associated with the Higgs field indicates potential flaws in the Higgs theory.
  • Some participants propose that the graviton, as a theoretical particle, should be included in the standard model, while others challenge the notion of treating it as a particle.
  • Concerns are raised about how to quantize the Higgs field, given its scalar nature, and the implications for understanding gravity.
  • A hypothesis is presented that gravity could potentially be repulsive, linked to the nature of antimatter and its interactions.
  • Discussions include the nature of forces, with gravity being characterized as uniquely attractive compared to other fundamental forces.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the integration of gravity into the standard model and the implications of the Higgs boson. The discussion remains unresolved, with no consensus on the relationship between gravity and the standard model or the nature of gravitational forces.

Contextual Notes

Participants note limitations in current theoretical models, particularly regarding the treatment of gravity and the Higgs field. There is an acknowledgment of unresolved mathematical steps and the dependence on definitions related to mass and force.

kurious
Messages
633
Reaction score
0
gravity and the standard model and Higgs theory

Massless particles always exist in a gravitational field, in the real universe.The standard model does not reflect this,so how can the standard model of particle physics be correct.And how can the Higgs theory of mass generation which is linked to the standard model,be correct?
Have we now reached the point in physics where to proceed further all
physical phenomena must be accounted for simultaneously?
 
Last edited:
Physics news on Phys.org
>> Massless particles always exist in a gravitational field, in the real universe.The
>> standard model does not reflect this,...

Care to explain this a bit more? Do you mean that photons are not explained by the standard model or do you think that gravity has a considerable influence on the subatomic level or did you mean something completely different?



>> Have we now reached the point in physics where to proceed further all
>> physical phenomena must be accounted for simulataneously?

No. I´d be very surprised if a theory for type 2 superconductors or the first quantum computers would take gravity into account, for example.

EDIT: Cut out my comments on unified theories because they were not really important and people might feel offended by them.
 
Last edited:
kurious said:
Massless particles always exist in a gravitational field, in the real universe.The standard model does not reflect this

The reason, I think, is that gravity is the weakest force among the 4 fundamental forces. The case for standard model is not yet closed until graviton and Higgs boson are all detected. The breakthroughs for standard model were the detections of W+, W-, and Z0 vector gauge bosons. The Higgs particle is a scalar boson which causes complication in the model.
 
In term of particle detection it's 3 against 2 for the standard model, not counting the 8 gluons which, to me, are not particles but mainly properties for a principle of directional invariance. Along the same line of thinking, I can also say that graviton and Higgs particle are not really particles but dimensional jumps of other known particles already in existence.
 
The standard model should incorporate gravity - gravity may be weak but it's impact on the overall substance of the theory could be large.I think that the fact that the mass of the Higgs particle and the masses of quarks and leptons can't be predicted
accurately (i.e to several decimal places) by the standard model suggests that the Higgs theory - which is linked to it - must be wrong.How can a theory about the generation of mass
be accurate when the mass of the particle associated with the Higgs field is so uncertain?
 
kurious said:
the masses of quarks and leptons

These are all detected and agreed with theory predictions (at low energy).

The predicted mass of the Higgs boson can only be confirmed when it is found. But the energy needed for its discovery is beyond current accelerator technologies. If a low energy effect of the Higgs boson can be theorized then it is considered as found.
 
Last edited:
kurious said:
The standard model should incorporate gravity

It does. The vector boson of gravity is the graviton. Graviton is a by product of standard model which is the quantization of different fields called quantum field theories (QFT). To close the case, graviton must be found. I think, superstring theories have more to say about the graviton and also the concept of supersymmetry. Once the graviton is found everything will be as clear as crystal is clear.

But the Higgs boson is a scalar boson and it is the mass that leads to the gravity force. So it must also be related to the graviton. But there is no theory of this relationship. The question is how to quantized a scalar field without a fundamental force?
 
Last edited:
Antonio Lao:
It does. The vector boson of gravity is the graviton. Graviton is a by product of standard model which is the quantization of different fields called quantum field theories (QFT).

Kurious:
What I meant was not that the standard model should predict a graviton but rather that the fact that every particle in the standard model exists in a gravitational field which fills the universe should be taken into consideration - theoretical models seem to take place in gravitational vacuums and they should not because this does not reflect the existence of particles in real life.Gravity and the standard model have not been reconciled because gravity and electromagnetism have not,and EM is part of the standard model.
How can quantizing the Higgs filed lead to gravitons - the Higgs is not space-time itself,is it?
 
Last edited:
kurious said:
theoretical models seem to take place in gravitational vacuums

In brane theory (offshoot of superstring), vector force models took place in just one brane while graviton connects two separated branes. All our reality can only be located in one brane. In a sense, a graviton is capable of transcending our physical reality into a separate reality of another brane universe.

kurious said:
How can quantizing the Higgs filed lead to gravitons - the Higgs is not space-time itself,is it?

The Higgs field is a scalar field with no inherent directional property. A vector field such as gravity field has a force to serve as its directional attribute. The problem is how do we quantize a scalar field? A field can easily be quantized iff there is a force.

The EM field has the EM force.
The Gluon field has the color force.
The weak field has the weak force.
The meson field has the pion force.

The forces are the exchange particles or carriers of the forces. The electroweak force share common carriers from EM and weak field.
 
  • #10
The Higgs field was invented in order to explain why some of the carriers of the electroweak force have mass (W+, W- and Z0 bosons). As can be noted all the other field particles have zero mass (photon, graviton, gluon, excluding pion which is really outdated concept superceded by the existence of quarks and the color force).
 
  • #11
The complication arising from having a force for vector fields is that gravity is known only to be attractive while the other forces can attract and also repel. So gravity field is a class of vector field all by itself and needed more ideas for its complete description.
 
  • #12
What if gravity is repulsive too but the repulsive particles have only a very short range field because something odd has happened to them.
Something has happened to the missing antimatter in the universe or
else we have to believe in some pretty fine tuning of the antimatter-matter ratio.Perhaps antimatter particles were fragmented in the early universe,
and this has removed the normal gravitational force from them.
It would be improbable that enough fragments would come together
at any point in space to collide with matter and annihilate.This is why we
don't witness such annihilations.
 
  • #13
kurious said:
What if gravity is repulsive too

This is easier said than done. Going off topic a bit, why does cold air sinks and hot air rises? Is it because cold air is denser? Why does supercool helium gas defies gravity? Why is it easier to lift a heavy object under water than on solid ground? Is gravity responsible for any of these cases? Or all of them?

kurious said:
why we don't witness such annihilations

The quantum vacuum fluctuations happen very fast. Although it is not possible to witness these events by the naked eye, the virtual fermions of matter and antimatter do interact with virtual photons in creations and destructions back and forth ceaselessly for all eternity.
 
  • #14
Kurious:
What if gravity is repulsive too

Antonio Lao:
This is easier said than done

Kurious:
Easily done if negative mass repels positive mass.Negative mass could have a short range gravitational field and might only be associated with fragmented antimatter.
 
  • #15
kurious said:
a short range gravitational field

Because of the observed nature of the fundamental forces, both gravity and EM are considered long range forces while weak and strong nuclear forces are considered short range forces. The balancing acts between these forces were responsible for the creation of nuclei in the early universe and subsequently the formations of neutral atomic configurations. The birth of hydrogen atoms. The thermonuclear fusions of hydrogen nuclei (single proton state - 2 up quarks 1 down quark) created helium nuclei then lithium nuclei then the rest of the chemical elements follow in the same processes of fusion reaction between succeeding heavier and heavier nuclei configurations. The binding energy (also in term of temperature) needed can be plotted against the mass number (number of proton in the nuclei) into a graph showing stability around iron nuclei and probable fusion reaction at lower mass number and probable fission reaction at higher mass number.

The binding energy curve shows clearly that at low mass number nuclei tend to come together but at higher mass number nuclei tend to break apart.
 
  • #16
Antonio Lao:
Because of the observed nature of the fundamental forces

Kurious:
It would be hard to observe a short range gravitational repulsion because a large accumulation of repulsive mass would not have a cumulative effect over a big distance unlike like a large accumulation of attractive mass .
 
  • #17
kurious said:
because a large accumulation of repulsive mass would not have a cumulative effect over a big distance

Actually, the gravitational potential energy given by

[tex]U = - \frac{GMm}{r}[/tex]

does allow either [itex]M[/itex] or [itex]m[/itex] to be both negative and the result is still acceptable. If just one mass is negative then the potential energy is positive which needs a new interpretation because it can appear that gauge symmetry is broken.
 

Similar threads

Undergrad New Constraints On The Higgs Boson Width
  • · Replies 11 ·
Replies
11
Views
4K
Undergrad Does the New Muon g-2 Measurement Indicate Physics Beyond the Standard Model?
  • · Replies 2 ·
Replies
2
Views
3K
Graduate Wilson Coefficient Values for b->s l l in the Standard Model: What Do We Know?
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad Particle Physics vs Quantum Field Theory vs Standard Model
  • · Replies 3 ·
Replies
3
Views
19K
Graduate My T-shirt and the Standard Model
  • · Replies 4 ·
Replies
4
Views
3K
Graduate What is the problem with the particle masses in the Standard Model?
  • · Replies 1 ·
Replies
1
Views
3K
Graduate How can the LRS model for leptons incorporate the Standard Model group?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad The standard model from loop quantum gravity via spinors octonions
  • · Replies 26 ·
Replies
26
Views
7K
Graduate In the standard model gravitron is a particle but Higgs boson is not?
  • · Replies 18 ·
Replies
18
Views
4K
Graduate Furey's superalgebra and the standard model
  • · Replies 4 ·
Replies
4
Views
3K