Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

145 submissions , 122 unreviewed
3,930 questions , 1,398 unanswered
4,853 answers , 20,624 comments
1,470 users with positive rep
501 active unimported users
More ...

Higgs Coupling - Fifth Force

+ 0 like - 0 dislike
44 views

To which of the four forces of nature does the coupling of the Higgs scalar field to other quantum fields ultimately belong to, if any? If it doesn't fall into any of the four known categories of forces, does that imply a fifth "force" of nature, or have I misunderstood the definition of force?

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user Optimus Prime
asked Oct 28, 2016 in Theoretical Physics by Optimus Prime (80 points) [ no revision ]
retagged Nov 8, 2016
Hi Optimus Prime. Bearing in mind this is a site for (and I quote from the tour) active researchers, academics and students of physics we expect people posting questions to have done at least some research. In this case the most obvious search would have immediately answered your question.

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user John Rennie
The Higgs is in the electroweak sector. As neutral it couples only with the weak coupling constant. (when a model appears which unifies gravity at the quantum mechanical level with the other three forces, it will also couple with the gravitational constant)

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user anna v

1 Answer

+ 0 like - 2 dislike

The fields in the Standard model can be put into three categories:

  1. Matter fields (quarks, leptons).

    a) Massless at the 'fundamental' level. Massive after aquireing mass via Higgs mechanism.

    b) Fermions

    c) Interact with each other only via other fields, e.g.

  2. Mediators of the interactions (gauge bosons). These are responsible for the presence of the 'forces'.

    a) Massless at the 'fundamental' level. W&Z bosons become massive after aquireing mass via Higgs mechanism. Photons and gluons are massless.

    b) Bosons

    c) Photons do not self-interact, others do. Note: yes, there is such thing as photon-photon scattering, but it only goes via other fields, not directly (as, say, in gluon-gluon case).

  3. Higgs boson

    a) Massive

    b) Boson

    c) Couples (interacts with) directly to the matter fields, providing them with masses. This type of interaction is named after Yukawa.

    d) Couples to electroweak gauge bosons, providing W&Z with masses.

    e) Self-interacts.

Now you see how special the Higgs field is. It is a boson which is not a mediator of interactions. It couples (directly!) to both matter fields and electroweak bosons. Typically people refer to d) as to the Higgs mechanism.

Interactions in e) and d) are typically not called 'forces' because they are not due to the presence of gauge bosons; see the discussion here.

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user mavzolej
answered Oct 28, 2016 by mavzolej (-20 points) [ no revision ]
By 2.a, do you mean to say that all mediators are massless? Where then would the W's and Z fall?

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user Optimus Prime
Ooooops my bad :) All the mediators (including W and Z) are massless at the more fundamental level, i.e. prior to acquiring masses via Higgs mechanism. I suggest to take a look at wiki articles about the Higgs mechanism, W&Z bosons, and also here.

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user mavzolej
By that rationale, you should also revise 1a an 1b , as your fermions would also be massless prior to symmetry breaking. Right?

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user Optimus Prime
Yep! Exactly like this. Also, check out this thread.

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user mavzolej
Since when are vector bosons ($W^\pm$, $Z$, $\gamma$, and gluons) not bosons?

This post imported from StackExchange Physics at 2016-11-08 14:07 (UTC), posted by SE-user Sean Lake

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
p$\hbar$ysicsO$\varnothing$erflow
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
To avoid this verification in future, please log in or register.




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...