# How does the Higgs field “Give mass”?

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• lindl
In summary, the Higgs field does not directly give particles mass, but rather its interaction with other particles through the Higgs mechanism allows for mass to be generated. This is due to the non-vanishing vacuum expectation value of the Higgs field, which is responsible for the masses of the gauge bosons and fermions through the Yukawa couplings. The Higgs mechanism also preserves the gauge symmetry of the electroweak standard model.
lindl
Problem Statement: How does the Higgs field “give mass”
Relevant Equations: The exact way that particles interact with the Higgs field and therefore create mass.

I’m trying to figure out how the Higgs field works, one problem is that while I originally though of the Higgs field like a medium that resists motion which therefore creates mass, I found that that is not the case. So how exactly does the Higgs field give mass? Where does the energy come from to give mass? Why don’t particles like the photon and gluon interact with the Higgs field?

This topic requires knowledge in advanced physics, which I don't have (so other members will be able to help you better). But go through this article published by APS:
https://physics.aps.org/articles/v6/111It says in one place:
The Higgs boson does not technically give other particles mass. More precisely, the particle is a quantized manifestation of a field (the Higgs field) that generates mass through its interaction with other particles.

sysprog
That's a great question that we don't really have the answered to that problem , because the mass of the Higgs seems to create instability or an incorrect gauge of the vacuum . it seems to be fined tuned at about 10*30 so in a sense there's a deep questions of why the particles from the standard model seem to have the masses that they have when the Higgs wants to have a heavier mass . I recommend you check out the hierarchy problem in physics

You can find the standard “classical” (there really are no classical spinor fields) treatment of the Higgs mechanism in any QFT textbook. But to sum it up what theorists refer to as mass in field theory is really just a quadratic term in the fields without derivatives, normally these violate gauge symmetry but the Higgs mechanism allows them to exist without symmetry violation.

In the case of fermions the mass term is essentially a coupling between the left and right-handed fermion fields. This is termed a Dirac mass and without the Higgs mechanism violates the SU(2) part of the electro-weak gauge symmetry since only the left-handed components transforms non-trivially (at all). The Higgs mechanism saves the day by coupling to the Dirac mass terms, giving what is called a Yukawa term, and preserving the gauge symmetry. An important consequence of this is that the fermion-Higgs couplings are proportional to the fermion masses, which has been well verified at the LHC if I remember correctly.

Boson masses come in very differently however. The uncharged Higgs particle that they found in the LHC is actually only a remnant of the full Higgs field and gets its mass from the “Mexican hat” Higgs self-interaction terms in the standard model. The massive gauge bosons (W+,W-,Z) get their masses from the Higgs-boson couplings.

vanhees71
What's also important to note is that due to the mexican-hat shape of the Higgs-field potential, the vacuum expectation value of the Higgs field is non-vanishing. If the symmetry were a global symmetry that would mean that there's spontaneous symmetry breaking, i.e., the ground state ("vacuum") were degenerate and there would necessarily be massless scalar bosons in the physical particle spectrum (the Nambu-Goldstone modes of some scalar or pseudoscalar fields), but that's NOT the case here, where the symmetry is a local gauge symmetry.

What rather happens here is that the field-degrees of freedom which would be the Nambu-Goldstone modes for a global symmetry now provide the necessary additional spatially longitudinal polarization states of the corresponding gauge bosons which get massive via their couling to the Higgs field. That must be so, because massless gauge bosons as spin-1 vector bosons have only 2 polarization degrees of freedom (like photons, where you usually choose the momentum-helicity single-particle basis to build up the Fock space, and the helicity can only take 2 values, ##\pm 1##, corresponding to left- and right-circular polarized photons) but massive spin-1 vector bosons have 3 spin-degrees of freedom. The additional spin-degree of freedom for each gauge boson that becomes massive through the Higgs mechanis thus is provided by the would-be Goldstone modes of the Higgs field.

In the usual minimal realization of the Higgs sector in the standard model you start with a weak-isospin doublet for the Higgs field, i.e., 4 real field-degrees of freedom. When Higgsing, i.e., choosing a gauge invariant Mexican-hat potential, where thus the vacuum expectation value of the Higgs doublet is non-vanishing, 3 of the 4 real field-degrees of freedom are the would-be-Goldstone modes and thus are "absorbed" into the corresponding gauge bosons that become massive.

In the case of the electroweak standard model the gauge group is ##\mathrm{SU}(2)_{\text{L}} \otimes \mathrm{U}(1)_{\text{Y}}##, and this group is Higgsed to the remaining ##\mathrm{U}(1)_{\text{em}}##. This means that out of 4 group dimensions 3 become Higgsed and thus of the corresponding 4 gauge bosons 3 get massive (these are the electrically charged ##W^{\pm}## and the electrically neutral ##Z^0## bosons mediating the weak interaction) and one stays massless (which is the electromagnetic field, i.e., the photon field, mediating the electromagnetic interaction).

Now another specialty of the electroweak standard model is that the gauge group is chiral. Thus the matter fields (leptons and quarks) cannot be simply taken massive, because this would explicitly violate the gauge symmetry, and in the case of a local gauge symmetry that would make the entire edifice obsolete! Thus you have to provide masses to the matter particles also via the Higgs mechanism, i.e., you couple the Higgs doublet gauge-invariantly to the matter fields. Staying with renormalizable interactions this leads to Yukawa couplings between the Higgs-boson field and the fermion fields for leptons and quarks. Then there's also another complication that in the quark sector the weak isospin eigenstates are not the mass eigenstates, i.e., you also need a socalled mixing matrix transforming between the mass and isospin eigenbasis of the quark fields (Cabibbo-Kobayashi Maskawa or short CKM matrix). This gives mass to the charged leptons (electrons, muons, tau leptons) and leaves the neutral ones (the corresponding neutrinos) massless.

Another danger with chiral gauge symmetries (and the electroweak standard model must be chiral in order to provide the observed breaking of parity symmetry by the weak interaction, realized as the "vector-minus-axialvector" maximal breaking pattern) is that there might be anomalies, i.e., chiral gauge symmetries which are valid for the classical field theory may become violated by quantization. Sometimes that's wanted for global gauge symmetries. E.g., in the standard model in the chiral limit there's a symmetry under ##\mathrm{U}(1)_{\text{A}}## transformations, but that symmetry is not realized in nature, and indeed it's found to be anomalously broken, and this is very welcome in the electromagnetic interaction of the pions since only with the anomaly you get the right decay rate for ##\pi^0 \rightarrow \gamma \gamma##.

For a local gauge symmetry an anomaly, however is letal, since this means that this local gauge symmetry were explicitly broken by quantizaing the theory and then would become obsolete. Fortunately in the case of the standard model, taking all the leptons and quarks (the latter with the specific charge pattern of -1/3 and 2/3 quarks in each family and their additional color degrees of freedom with the color Group being ##\mathrm{SU}(3)## of QCD leads to a perfect cancellation of the possible anomaly of the ##\mathrm{SU}(2)_{\text{L}}## chiral gauage symmetry, and thus the ew. standard model is consistent.

Ok so please excuse me if any thing I ask is common knowledge. I have several questions.

With the wave function in the Higgs Field, why do we not show effects to the particles thru it interaction in exchanging of energy & mass.

In theory the Higgs Field is the fabric that binds all particles. So wouldn't any disturbance to the wave function of the field, directly affect the position of any particle.

Since the quantum is a solid moving thru the Higgs field wouldn't it be bound by wave logic?

TheLejund said:
With the wave function in the Higgs Field, why do we not show effects to the particles thru it interaction in exchanging of energy & mass.

This sentence does not make sense. And I mean it literally, in english.

TheLejund said:
In theory the Higgs Field is the fabric that binds all particles.

No it's not.

TheLejund said:
Since the quantum is a solid moving thru the Higgs field

No it's not.

HomogenousCow said:
In the case of fermions the mass term is essentially a coupling between the left and right-handed fermion fields. This is termed a Dirac mass and without the Higgs mechanism violates the SU(2) part of the electro-weak gauge symmetry since only the left-handed components transforms non-trivially (at all). The Higgs mechanism saves the day by coupling to the Dirac mass terms, giving what is called a Yukawa term, and preserving the gauge symmetry. An important consequence of this is that the fermion-Higgs couplings are proportional to the fermion masses, which has been well verified at the LHC if I remember correctly.
Just to expand this description of the fermion masses, what is happening is that the, say, electron is flipping chirality as it propagates. When it flips from left-handed to right-handed the electron emits a neutral Higgs into the background vacuum, and when it flips from right to left the electron absorbs a neutral Higgs from the background vacuum. The neutral Higgs forming the vacuum exist in a Boss-Einstein condensate (superfluid) and have zero energy and momentum, so they don't exert any drag force on the electron. (Superfluids are non-viscous.) However the neutral Higgs does carry weak isospin -1/2 and weak hypercharge +1, so these charges do not appear conserved - unless we take the Higgs interactions into account.

The neutrino, in the electroweak model, does not interact with the neutral Higgs, and so acquires no mass.

## 1. What is the Higgs field and how does it give mass?

The Higgs field is an invisible energy field that permeates the entire universe. It is responsible for giving particles their mass through a process called the Higgs mechanism. This mechanism involves the interaction between particles and the Higgs field, which results in particles gaining mass.

## 2. How was the existence of the Higgs field discovered?

The existence of the Higgs field was predicted by the Standard Model of particle physics, but it was not until the discovery of the Higgs boson in 2012 by the Large Hadron Collider (LHC) that its existence was confirmed. The Higgs boson is a particle that is associated with the Higgs field and its discovery provided evidence for the existence of the field.

## 3. What would happen if the Higgs field did not exist?

If the Higgs field did not exist, particles would not have mass and the universe would look very different. Without mass, particles would not be able to form atoms, and therefore, there would be no matter as we know it. The Higgs field is essential for the existence of our universe as we know it.

## 4. Does the Higgs field give mass to all particles?

No, the Higgs field only gives mass to some particles, specifically the elementary particles in the Standard Model, such as quarks and electrons. Other particles, like photons, do not interact with the Higgs field and therefore do not have mass.

## 5. How does the Higgs field interact with other fundamental forces?

The Higgs field interacts with other fundamental forces, such as the electromagnetic force and the strong and weak nuclear forces, through the Higgs boson. The Higgs boson is responsible for giving mass to the particles that make up these forces, and without it, these forces would not exist in the way that they do. The Higgs field is a crucial component in our understanding of the fundamental forces of the universe.

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