Could Quantum Gravitons Have Three Types and Short Lifetimes?

  • Context: Graduate 
  • Thread starter Thread starter Orion1
  • Start date Start date
  • Tags Tags
    Gravitons Quantum
Click For Summary

Discussion Overview

The discussion centers around the concept of gravitons, their potential types, and their lifetimes within the framework of the Standard Model and beyond. Participants explore the implications of having multiple graviton types, the relationship between graviton properties and the families of particles in the Standard Model, and the nature of gravitation as a long-range force.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that if the Standard Model implies three families of particles, there could similarly be three types of gravitons (electro-graviton, mu-graviton, tau-graviton).
  • Others argue that the number of families in the Standard Model is not strictly dictated by it and question the assumption that gravitons must have a short lifetime.
  • There is a suggestion that if gravitons have a short lifetime, it raises questions about how gravitation can be a long-range force.
  • Some participants mention the existence of graviton partners in certain symmetry groups, such as gravitinos in supersymmetry, while others express skepticism about the validity of supersymmetry.
  • One participant outlines various theories related to gravitons, including Newton's theorem, general relativity, and string theory, and questions the necessity of curved space-time in the context of graviton gauge bosons.
  • There is a discussion about the relationship between the number of gauge bosons and the families of fermions, with some asserting that the correlation is not straightforward.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the number of graviton types or the implications of their lifetimes. Multiple competing views remain regarding the relationship between the Standard Model and graviton properties, as well as the validity of various theoretical frameworks.

Contextual Notes

Participants express uncertainty about the assumptions underlying their claims, particularly regarding the existence of primordial graviton Cosmic Background Radiation and the implications of graviton lifetimes on gravitational interactions.

Orion1
Messages
961
Reaction score
3


Given that the Standard Model states that only three families exist, and given that gravitons can exist with mass, why could it not be implied that there are also three graviton types?:

[tex]g^0_e[/tex] - electro-graviton
[tex]g^0_\mu[/tex] - mu-graviton
[tex]g^0_\tau[/tex] - tau-graviton

Given that no primordial graviton Cosmic Background Radiation exists, can it also be implied that all 'implied gravitons' must have a short 'lifetime'?

Given that gravitons have a short 'lifetime', what could have been their most probable decay products?

 
Last edited:
Physics news on Phys.org
The standard model doesn't state that only three families exist. It just seems so from the experimental data so far. (See here for a fit of the data to the standard model calculations)

The fact that there are (probably) 3 families has to do with the weak force. Why should this influence the gravitational force as well? After all, there is also only one type of photon.

Why is it 'given that no primordial graviton Cosmic Background Radiation exists'? Experiments are still running (it's just hard to measure gravitons: their interaction is quite weak to say the least)...

Why is it 'given that a graviton has a short lifetime'?
 
Originally posted by Orion1


Given that the Standard Model states that only three families exist, and given that gravitons can exist with mass, why could it not be implied that there are also three graviton types?:

The Standard Model calls for three families of fermions. The fundamental forces are mediated by gauge bosons, of which the graviton is a "member" (spin-2). The number of bosons which correspond to a particular force is determined in part by the number of generators of the symmetry group, hence why there is 1 photon, 3 weak vector bosons, and 8 gluons.
 


Originally posted by GRQC
The Standard Model calls for three families of fermions.

Are you sure? I always thought that the number of families is not dictated by the standard model. See also this thread.
 


Originally posted by suyver
Are you sure? I always thought that the number of families is not dictated by the standard model. See also this thread.

The Standard Model has three generations of fermions. If there are shown to be more than three, then the Standard Model is incorrect and needs to be adjusted. Calling for a fourth sterile neutrino, for example, constitutes an extension of the current Standard Model.

I suppose it's largely an issue of semantics.
 
Originally posted by Orion1

Given that gravitons have a short 'lifetime', what could have been their most probable decay products?

If gravitons have a short lifetime, then how can gravitation be a long-range force?
 
We don't know the amplitude of a graviton. What we do know, is that to first order, it pops out something very close to general relativity

However, it is the case that they may exist graviton partners in some symmetry group. For instance, SUGRA outputs a supersymmetric partner, called the gravitino.

As far as the 3 families in the SDM, it is not known why they are there, you have to go to theories beyond the SDM to get that.
 
Originally posted by Haelfix
However, it is the case that they may exist graviton partners in some symmetry group. For instance, SUGRA outputs a supersymmetric partner, called the gravitino.

Only if you believe SUSY. But hey, it's 50% verified at this point, right? :smile:
 
The Standard Model calls for three families of fermions. The fundamental forces are mediated by gauge bosons, of which the graviton is a "member" (spin-2). The number of bosons which correspond to a particular force is determined in part by the number of generators of the symmetry group, hence why there is 1 photon, 3 weak vector bosons, and 8 gluons.

However, it is the case that they may exist graviton partners in some symmetry group. For instance, SUGRA outputs a supersymmetric partner, called the gravitino.

Given that a graviton is a spin-2 gauge boson and there are 3 vector bosons, could it be implied that there are also 3 vector gravitons with 3 gravitinos?

Symmetry Generator# = Fermion Family#

3 vector gravitons: (mass symmetry)
[tex]g^0_e[/tex] - electro-graviton
[tex]g^0_\mu[/tex] - mu-graviton
[tex]g^0_\tau[/tex] - tau-graviton

3 vector gravitinos: (supersymmetry)
[tex]gv^0_e[/tex] - electro-gravitino
[tex]gv^0_\mu[/tex] - mu-gravitino
[tex]gv^0_\tau[/tex] - tau-gravitino

I suppose such a system may be trans-Standard Model, I am only implying that 'leptonic-like' gauge vector gravitons with supersymmetry may exist with mass gauged bosonic gravitons.

According to my understanding, there are several types and classes of graviton theories, including a String Theory model, which are primarily based upon five theories:

1. Newton's Theorem (Gravitation) (relative spin)
2. Curved-Space-Time (general relativity) (spin 2 ?)
3. Graviton Waves (inverted Space-Time Waves), (supernovae produced) (spin 2 ?)
4. Graviton Gauge Bosons (mass, field exchange particles) (spin 2)
5. String Theory (vibrating strings) (spin 2)

If gravitation is really a product of the field exchange of Graviton Gauge Bosons, they why would it be necessary to curve space-time for this effect?

If gravitation is really a product of Graviton Waves (inverted Space-Time Waves), supernovae should produce enormous inverted amplitudes, which should have been optically detectable via the lensing effect.

If gravitation is really a product of first order Graviton Gauge Bosons, it is reasonable to imply that Graviton Gauge Bosons with, or without mass or charge must exist at higher orders to complete Gauge Theory or GUT, or TOE.

[/color]
 
Last edited:
  • #10
Originally posted by Orion1
Given that a graviton is a spin-2 gauge boson and there are 3 vector bosons, could it be implied that there are also 3 vector gravitons with 3 gravitinos?
[/color]

There are 3 bosons for weak interactions, because that is the associated group structure. The three weak bosons (Z, W+, W-) have nothing to do with the three families of leptons, short of being responsible for flavor-changing interactions.

There is 1 photon and 8 gluons -- which has even less of a correlation.
 

Similar threads

Undergrad Does the graviton have to exist?
  • · Replies 6 ·
Replies
6
Views
4K
Undergrad Is Toponium a Reality Despite Top Quark's Rapid Decay?
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad New Constraints On The Higgs Boson Width
  • · Replies 11 ·
Replies
11
Views
4K
Graduate Twistors and celestial holography
  • · Replies 21 ·
Replies
21
Views
7K
Graduate Branching ratios | Higgs phenomenology
  • · Replies 13 ·
Replies
13
Views
4K
Undergrad Progress In Calculating The HLbL Contribution To Muon g-2
  • · Replies 0 ·
Replies
0
Views
4K
Graduate How the g factor comes from QFT?
  • · Replies 1 ·
Replies
1
Views
3K
Graduate Hints for lepton flavor violation in B-hadron decays
  • · Replies 1 ·
Replies
1
Views
3K
Graduate Higgs inflation and quadratic gravity
  • · Replies 1 ·
Replies
1
Views
4K
Graduate Clarification regarding argument in EPR paper
  • · Replies 58 ·
2
Replies
58
Views
5K