Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [higgs]

This higgs field breaks electroweak symmetry and provides mass to particles though a process called the higgs mechanism. The excitation of the higgs field is called a higgs boson.

2
votes
0answers
36 views

Lepton flavor violating process on loop level $\mu \rightarrow e \gamma$ via Higgs, Divergent integral

I am stuck with calculating the proces $\mu \rightarrow e \gamma$ as in this diagram: I wrote down the matrix element like this: $$ \mathcal{M}=\bar{u}(p-q)\left[\int \frac{d^4k}{(2\pi)^4}A\frac{(k+...
2
votes
0answers
17 views

Why do we need the two higgs doublet model?

Why do we add an extra doublet to the two higgs doublet model?I mean what are the conditions due to which we had to add an extra doublet. What are the limitations with only one doublet and how 2HDM ...
2
votes
2answers
140 views

Electric charge of the Higgs field

The Higgs field is \begin{equation} \Phi = \left( \begin{array}{cc} \phi_{1} + i\phi_{2} \\ \phi_{3} + i\phi_{4} \end{array} \right) \tag{1} \end{equation} with $\phi_{1}$ and $\phi_{2}$ ...
0
votes
1answer
18 views

Higgs field and Time dilation

I am wondering if the Higgs field is related to time dilation. Photons travel at the speed of light, but muons are very close but never at the speed of light. Would Muons be slowed by the interaction ...
1
vote
0answers
29 views

Charge operator applied to matrix multiplets

In the context of SM ($SU(3)_C\otimes SU(2)_L\otimes U(1)_Y$) the charge operator is $Q_{SM} = T_3 + \frac{Y}{2}\mathbb{I}_2$ and gives us the fermions charges. Here $T_3=\frac{1}{2}\sigma_3$ is the ...
1
vote
1answer
77 views

$W$, $Z$ bozons and fermions gained their masses WHEN?

I have read these questions: How does the Higgs mechanism work? How does the Higgs boson give mass to other elementary particles like electrons? What is the difference between the Higgs Boson ...
3
votes
1answer
34 views

What is $\mathbb{Z}_2$ Parity?

While reading about exotic decays of Higgs boson one of the simplest interaction that we come up with which leads to BSM decays is: $$\Delta L = \frac{\zeta}{2}s^{2}|H|^{2}.$$ This is the ...
1
vote
0answers
22 views

Interpretation of a CLs exclusion plot

I have some trouble with the interpretation of this plot. The plot on the right shows the CLs values for the SM Higgs boson hypothesis as a function of the Higgs boson mass in the range 110–145 GeV. I ...
1
vote
0answers
26 views

Electroweak phase transition and finite temperature field theory formalism

We do our calculations in standard quantum field theory at zero temperature where we can derive pole mass and renormalized mass and ... Due to my understanding, pole mass is independent of any energy ...
2
votes
1answer
34 views

Does two Higgs doublet model predicts two Higgs bosons?

Does 2HDM predict two higgs boson? Why two doublets are needed? I need a simplified answer as i am new to BSM
5
votes
2answers
229 views

Higgs-Mechanism: Why are gauge boson masses not protected by gauge symmetry

In non-spontaneously broken QFT like QED the gauge bosons cannot have a mass due to gauge symmetry (follows from Ward identity). Also they have only 2 polarizations. However in a spontaneously broken ...
0
votes
1answer
53 views

Why is the Higgs $CP$ even?

Why was it always assumed that the Higgs boson is a CP even particle? I understand that experimentally, it just is so but I am under the impression that before its discovery people took it to be CP ...
-6
votes
1answer
77 views

Is the mass of a particle determined by the extent to which it interacts with other particles? [closed]

This is more a question about the Higgs field than anything else. If you were to take, for example, a neutrino and send it out into empty space how could you determine that it has a mass in the first ...
1
vote
0answers
49 views

How do we determine who eats who (or which field gets massive) in a Higgs phase transition?

Consider the following theory in which a $2$-form field $B_{\mu\nu}$ with field strength $P_{\alpha\mu\nu}=\partial_{[\alpha}B_{\mu\nu]}$ is coupled to a $3$-form gauge field $C_{\alpha\beta\gamma}$ ...
1
vote
1answer
39 views

What was the prediction of the standard electroweak theory about the $W$ and $Z$ boson masses?

The standard electroweak theory has two coupling constants $g$ and $g^\prime$. In this theory, the $W$ mass and $Z$ mass are given by $$M_W=\frac{1}{2}gv,~M_Z=\frac{1}{2}(g^2+g^{\prime 2})^{1/2}v$$ ...
0
votes
1answer
24 views

Higgs Coupling in the moments after the Big Bang

How did the Higgs interaction differ due to the densities, temperatures, pressures, etc. in the moments following the big bang? I am aware that around $10^{-43}$ seconds all the fundamental forces ...
1
vote
1answer
42 views

Screening of the electric field in the Higgs phase

Dvali states in his paper on Three-Form Gauging of axion Symmetries and Gravity that “As usual, in the Higgs phase the electric field is completely screened in the vacuum,” and in another ...
1
vote
0answers
13 views

Associated production mode of Higgs production at Tevatron

We know that at LHC the dominant mode of Higgs Production is Gluon Gluon Fusion, followed by Vector Boson Fusion, and then by Associated production. Although Tevatron did not show any significance ...
0
votes
2answers
61 views

How does entanglement create empty space?

It is claimed that empty space is full of quantum fields which their waves perfectly cancel out each other, but this can only happens when all the waves are entangled. Is this claim valid because I ...
1
vote
1answer
37 views

Does the Higgs VEV depend on the gravitational potential?

If I take the non-relativistic limit of the Klein-Gordon equation in a curved space-time I will get a contribution from the Newtonian gravitational potential. Shouldn't this gravitational contribution ...
0
votes
1answer
51 views

Don't matter-antimatter annihilate each other completely releasing energy as photon?

Matter and antimatter should annihilate each other completely releasing energy in the form of photon, however it is discovered that smashing electron and positron together can also spew out higgs ...
2
votes
1answer
66 views

Why is it doubtful that higgs field gives neutrino mass?

I read some articles mostly claiming that if neutrino is their own antimatter than they could get their mass from some other source rather than the higgs field, and I can't probe any further because ...
36
votes
6answers
10k views

Is the Higgs boson an elementary particle? If so, why does it decay? [duplicate]

The Higgs boson is an excitation of the Higgs field and is very massive and short lived. It also interacts with the Higgs field and thus is able to experience mass. Why does it decay if it is ...
0
votes
0answers
35 views

Where can I find the detailed calculation for the mass of the lights Higgs boson in MSSM?

can somebody mention where the mass of the lights Higgs boson in MSSM (minimal supersymmetric standard model) is discussed? I need a detailed and thorough explanation of the subject mater. I ...
11
votes
2answers
1k views

Why can a particle decay into two photons but not one?

I recently read an old physics news about the Higgs boson where it was observed to decay into 2 photons and I was wondering why it wouldn't have decayed into a single photon with the combined energy ...
0
votes
2answers
122 views

What gives mass to black hole?

I like to know when a dying star collapsed into a black hole, is there anything inside or on the event horizon that is interacting with higgs field?
0
votes
1answer
54 views

Scalar particles are described by a real scalar field or by a complex one?

Well, in the title is already stated my main question. I know you can use a complex scalar field to describe two real scalar fields, by using just one that involves both of them. But, in the modern ...
0
votes
0answers
13 views

Do higgs field affect rest mass and relativistic mass? [duplicate]

I know most of the "mass" comes from the binding energy such as gluon but suppose I apply a force on a matter particle, do I change the interaction between the particle and the higgs field? How does ...
2
votes
1answer
30 views

What happens to the massive gauge bosons in a simple Little Higgs model?

I'm trying to understand a simple Little Higgs (toy) model where the Higgs doublet is made of pseudo Nambu-Goldstone Bosons generated by breaking the symmetry from $SU(3)_L\times U(1)_Y$ to $SU(2)_L\...
0
votes
1answer
50 views

Higgs Feynman Diagrams

We have been told to compute the amplitude of these diagrams: I am struggeling with some basic points( I've only computed QED diagrams such as Bhabha scattering). Do you use $\epsilon$ for the ...
0
votes
1answer
61 views

Can higgs field ripples like gravitational wave?

Gravitational wave are produced when 2 massive objects orbit each other at high speed or collide, how about higgs field? can it ripples and what sort of event can cause it to ripple?
2
votes
1answer
119 views

Why did David Tong say that the global topological $U(1)$ symmetry is unbroken in Higgs phase?

In the paper A Duality Web in 2+1 Dimensions and Condensed Matter Physics by Seiberg, Senthil, Wang, and Witten, they studied the particle-vortex dualities in $2+1$ dimensions. On page 20, section 3....
1
vote
1answer
53 views

The production of $b$ ($b$ bar) quarks

I have a question, please if there anyone helps me to understarnd how we distinguish the production pair of quarks $b$ ($b$ bar) it comes from a QCD background or comes from higgs decay?
0
votes
0answers
13 views

Explaining the concept of background noise and signal in Higgs decay to 4 leptons or 2 gammas using an analogy of matlab simulation

I am not sure if this is the right forum to ask this question. But my main concern is to explain the idea of background/signal in Higgs decaying to 4 leptons or 2 gammas. I am absolutely not trying to ...
2
votes
1answer
152 views

Why the photon doesn't acquire mass with the Higgs mechanism?

I did the computation that from $$(0,v)^{T}(\partial_\mu+igA_\mu^a\tau^a+i\frac{g'}{2}B_\mu)(\partial_\mu-igA_\mu^b\tau^b-i\frac{g'}{2}B_\mu)(0,v)$$ with $(0,v)$ being the expectation value of the ...
2
votes
0answers
29 views

Higgs decay at higher energies

If I look at the expected Higgs decay BR's vs. $m_H$ the WW and ZZ dominate over the tt decay mode in the over tt threshold region. From the mere couplings: $g_{ffH} = \sqrt2 m_f /v$ $g_{VVH} = 2 ...
3
votes
2answers
70 views

How do know that Goldstone Boson actually become the longitude degrees of freedom in W+,W- and Z boson?

In many Quantum Field Theory text books they says these about Spontaneous Breaking and Higgs mechanism like this In unitary gauge, the Goldstone Bosons are eaten by $W^\pm$ and Z and become their ...
1
vote
0answers
29 views

Symmetry breaking with Kinetic term dominating the Potential on a Lagrangian

Suppose a Lagrangian $L$ for a scalar field $\phi$, consists of a kinetic term and a Mexican-hat type potential. I am aware that if the vacuum has symmetry $H \subset G$ while the Lagrangian has ...
5
votes
1answer
124 views

Is the electroweak $SU(2)$ gauge symmetry an exact symmetry in Standard Model before spontaneous symmetry breaking?

In Standard model, components of a $SU(2)$ doublet (for example $u$ and $d$) have different masses. This means there is no $SU(2)$ symmetry, but I think it is okay because the $SU(2)$ symmetry is ...
1
vote
0answers
39 views

Hierarchy problem and loop quantum gravity

According to https://en.wikipedia.org/wiki/Hierarchy_problem#Finite_Groups. Hierarchy problem can be theoretically solved using symmetry of certain bosonic string theory on the Leech lattice (though ...
1
vote
3answers
278 views

Given the transformation of $SU(2)$ triplet $\vec{\phi}$ how to find the transformation of ${\Phi}\equiv\vec{\phi}\cdot\vec{\tau}$?

Given the transformation of a $SU(2)$ triplet $\vec\phi$ $$\phi\to \exp{(-i\vec{T}\cdot\vec{\theta})}~\vec\phi\tag{1}$$ (in the question here by @physicslover) how does obtain the transformation of $\...
7
votes
1answer
124 views

Counting degrees of freedom in the Higgs mechanism for different gauges

I am wondering how to count the degrees of freedom (dof) for a massive gauge field in different gauges. I've been reading some other answers, but haven't found a solution yet. I am looking at the ...
1
vote
1answer
68 views

Like the Higgs sector of the standard model, is there a SUSY sector which is also such a sector?

This question arose from an application of the virial theorem that showed how Bose-Einstein condensates of astrophysical dimension could arise from condensing clouds of normal phase bosons. If these ...
0
votes
1answer
112 views

How does something start interacting with the Higgs field?

When two high energy photons are smashed together they create a matter-antimatter pair. The photons do not interact with the higgs field, but when they convert into matter-antimatter pair, they start ...
2
votes
1answer
110 views

What are significant applications of the Higgs Boson itself in the standard model?

I understand that the Higgs Field grants mass to all the matter in the universe, and is equally distributed in all parts of it, but it was the Higgs Boson that was discovered at the LHC, and ...
0
votes
1answer
33 views

Rest frame of massive photon in Meissner–Ochsenfeld effect

The Meissner–Ochsenfeld effect together with spontaneous symmetry breaking and the London Equation yields $(\Box+M^2)A^\mu=0$ and gives photon an effective mass $q\sqrt{\frac{n_c}{m_c}}$ Which is ...
0
votes
2answers
85 views

Interacting Quantum Fields in Curved Spacetime

I was thinking this night that how would the fields interaction or the vacuum expectation value of Higgs field changes when spacetime is not flat? e.g., the higgs field interact with the electron ...
-1
votes
1answer
42 views

If the Higgs field was densified a little more, can the physical constants such as Planck Values be changed?

According to theory, the Higgs field is at everywhere in the space. So that, the mass is existing by interaction of energy (in some way) with this field. And according to this the space vacuum has an ...
1
vote
1answer
50 views

Higgs field interactions [duplicate]

Where does the Higgs field get the energy which it transfers when some particles interact with it? And how do these interactions give mass to other bodies?
-4
votes
1answer
56 views

Has quantum mechanics been able to define the centre of a black hole? [closed]

It is said that quantum mechanics has defined everything we observed everything so far, but did it predict the existence of the Higgs Boson beforehand and has it been able to define the Singularity?