5
votes
1answer
94 views

The process $\mu^+\mu^-\rightarrow hh$

I am doing some calculations in the Standard Model. I have a question that seems rather simple but makes me think a lot. I want to compute the cross section of the following process at the leading ...
5
votes
3answers
430 views

Does the Higgs field really explain mass or just reformulate it? What about charge?

The mass of a particle used to be considered a fundamental and intrinsic property of the particle; on the same level as other properties such as charge, spin, chirality/helicity. Due to the Higgs ...
2
votes
0answers
59 views

How does the Higgs Particle Decay?

Background: It is my understanding that the Higgs Boson is a fluctuation of the Higgs field. It also is not very stable and decays into a plethora of other particles. If all other particles interact ...
2
votes
1answer
69 views

What is the difference between a QCD “glue ball” and a Higgs Boson?

Although they have never been observed, theoretically gluons can exist outside of the nucleus of an atom in the form of a "glue ball". Since the predominant mechanism of Higgs creation at the LHC was ...
6
votes
1answer
176 views

Why mass terms are forbidden?

I would like to clarify my understanding on why mass terms in Lagrangians of gauge theories are forbidden. It's often repeated that particle masses are forbidden by electroweak symmetry because it is ...
1
vote
1answer
97 views

Higgs field in space around us?

Is the higgs field in space around us? I understand it as that the higgs field has a constant value on every space time point, is that right? And this value is the vacuum expectation value. This ...
2
votes
1answer
197 views

Fermion mass Higgs mechanism

How get fermion like a electron a mass through the higgs-mechanism? Can someone explain me this with formulas (Lagrangian)? I know that the Yukawa interaction has something to do with, is that right? ...
1
vote
1answer
100 views

Why are the Z boson and photon different?

If I understand right the Z boson and photon are both a mix of the same two bosons, the W_3 and the B boson of weak isospin. If the Z boson and photon are both made of the same bosons, then they ...
4
votes
3answers
212 views

Virtual Higgs boson?

Can particles emit a virtual Higgs boson in a similar manner to the way a virtual photon is emitted?
1
vote
1answer
71 views

How is a Higgs boson created?

I have read a lot on Higgs bosons, yet I do not fully comprehend how they are created and how they are "flicked off" the Higgs field. I have also had trouble comprehending why a Higgs boson quickly ...
2
votes
1answer
48 views

Why is it possible to expand the SM Higgs field in its second component only

In the lecture, the professor said something along the lines of: "After a suitable gauge transformation, the standard model higgs field can be expanded as $$\phi =\left(\begin{array}{c} 0 \\ v+H(x) ...
1
vote
1answer
58 views

What are the Generators of the electroweak interaction after symmetry breaking. (SM)

In the standard model (omitting the QCD part), we start off with the set of generators $T_1$, $T_2$, $T_3$, $Y$ for the four-parametric gauge group $SU(2)_L \times U(1)_Y$. We then define a new ...
0
votes
1answer
89 views

Is the Higgs particle the final one predicted by the Standard Model? [duplicate]

Are there any other particle predictions by the standard model?
2
votes
1answer
193 views

Is Higgs mechanism necessary in QCD?

As we known, we introduce Higgs mechanism into Standard model to explain mass of Gauge boson, lepton and neutrino(maybe?). Higgs mechanism is necessary for electroweak theory because gauge symmetry ...
3
votes
0answers
74 views

Were fermions ever massless?

In a discussion of the Standard model and Higgs mechanism it was claimed that accordingly: "During an early phase of the cosmos all fermions were massless." I wonder whether this claim can be ...
2
votes
1answer
93 views

Does the decay of the Higgs Boson create up or down quarks?

Does the decay of the Higgs Boson create up or down quarks?
1
vote
1answer
139 views

The Higgs explains how particles acquire mass. Could it explain how much?

It's my understanding that nothing in the Standard Model predicts the mass values of the fundamental particles, so I guess that means we don't currently know how to make models of Higgs interactions ...
1
vote
0answers
110 views

“Original” coupling constant of the Higgs with the electron, taking into account renormalization

I read Peskin, Schroeder, "An introduction of quantum field theory". Formula (20.100) gives the electron mass after the Higgs mechanism as $m_e=\frac{1}{\sqrt{2}}\lambda_e v$ Here $v$ is related to ...
2
votes
1answer
175 views

Is the Higgs mechanism needed for Quantum Field Theory?

The NY Times article on Firewalls today has the following paragraph: Quantum field theory is how the world works [quoting a physicist]. It had a major triumph just a year ago, when the Higgs ...
0
votes
3answers
61 views

Predicting the mass of the Higgs particle

Physicists in Europe said that only after combining data collected at a laboratory in Switzerland with data collected at a laboratory in the U.S, were they finally able to announce the discovery of a ...
6
votes
1answer
189 views

Fundamental Higgs vs. pseudo-Nambu-Goldstone boson: experimental fingerprints

If we consider the 126 Higgs-like boson as a pseudo-Nambu-Goldstone boson, what are the experimental fingerprints of that case? What are the main differences, in a purely effective field theory ...
2
votes
2answers
119 views

What are the consequences in high-energy of the non-interaction of the Higgs Field?

At high-energies when the Higgs field won't affect (interact with) particles, when the symmetry breaking won't occur, what would be $\rm W\pm$ or $\rm Z^{0}$ bosons speed if they would then have a $0$ ...
2
votes
2answers
174 views

$\left(H^\dagger H\right)^2$ is invariant under $U(1)\times SU(2)$?

Is it true that $\left(H^\dagger H\right)^2$ is invariant under $U\left(1\right) \times SU\left(2\right)$ where $H$ is the Higgs field $(1,2,1/2)$? Does this invariance imply that its hypercharge ...
2
votes
1answer
357 views

Why some particles interact with the Higgs field and others don't?

Why some particles interact with the Higgs field and others don't? Higgs doesn't explain that much: why some particles have mass and others don't? is like why some particles interact with the Higgs ...
3
votes
1answer
202 views

Relation of Higgs couplings to masses of fundamental particles

The standard model has 12 massive leptons and 2 massive bosons other than the Higgs. My understanding of the Higgs mechanism is at about the level of this article, which goes as follows. Start with ...
4
votes
1answer
172 views

What if EM or QCD was spontaneously broken?

Suppose that Standard Model Higgs mechanism broke electromagnetism, by e.g. veving the charged component of the doublet, so that the photon was massive with $m_\gamma\sim v$. Could such a Universe ...
14
votes
1answer
217 views

Infrared-free QED and Higgsless standard model phenomenology

This is one of those "what if" fantasy world type questions. I like hard sci-fi so please no "well, you changed one thing about the world so now anything goes." :) What if the Higgs had no vev? That ...
2
votes
1answer
137 views

How to find the Higgs coupling with a mixing matrix?

It is known that the couplings to the Higgs are proportional to the mass for fermions; $$g_{hff}=\frac{M_f}{v}$$ where $v$ is the VEV of the Higgs field. I'm trying to figure out why this is true ...
4
votes
1answer
53 views

Higgs VEV in terms of measurements on an ensemble?

Let $A$ be a Hermitian operator corresponding to some observable. If we prepare $N$ identical systems in the state $\psi$ and measure this observable in each system, the average of the measurements ...
3
votes
1answer
276 views

What breaks the symmetry between the electromagnetic and weak nuclear force?

I know the electromagnetic force is mediated by a photon and the weak nuclear force is mediated by two massive bosons. Are there any other insights into why the masses are so different?
1
vote
1answer
132 views

Does the Higgs mechanism address the spin statistics problem?

Since the Higgs mechanism is so intimately tied to binding together massless chiral fermions, does it happen to have anything to say about the spin statistics issue? I'm actually assuming the answer ...
3
votes
2answers
158 views

Do any good theories exist on why the weak interaction is so profoundly chiral?

I find the profound asymmetry in the sensitivity of left and right chiral particles to be one of the most remarkable analytical observations captured in the Standard Model. Yet for some, I've not ...
0
votes
1answer
140 views

why drag cause mass in higgs field ? how could drag cause mass?

why in higgs field drag cause mass? drag is force in general not mass Higgs field- Inquiring Minds - Questions About Physics how drag of higgs field cause mass?
2
votes
0answers
194 views

Do all the particles acquire mass in the Standard Model due to the Higgs mechanism only?

I know that a mass term for an intermediate boson is not compatible with the gauge symmetry. But in principle a mass term for the electron field does not violate a gauge symmetry. However to build an ...
1
vote
2answers
377 views

What is the expectation value of the number operator when the vacuum has a VEV?

The number operator N applied to a field whose vacuum has zero VEV gives $N|0>=0$. What if we apply it to the Higgs field? The background of this question is that in popular scientific accounts, ...
3
votes
1answer
286 views

Higgs boson in LHC

Recently,the higgs bosons are discovered in LHC. My question is How did they come to know that the particle that are created are actually Higgs boson? On the basis of which properties,they ...
6
votes
1answer
248 views

Spin of 125 GeV Higgs boson

Can someone please explain to me why (according to decay of Higgs boson into 2 photons) Higgs boson cannot have spin $S=1$?
4
votes
1answer
549 views

Why is mass renormalization insufficient to explain electron mass?

In the Standard Model, I understand that the mass of the electron is assume to arise from two effects: A bare mass given by Yukawa interaction with the Higgs field, and A mass correction from mass ...
4
votes
1answer
595 views

Relationship between hierarchy problem and higgs fine tuning?

I often hear of hierarchy problem being used synonymous with Higgs fine tuning (esp with regards with motivations for SUSY). What exactly is the relationship between the two problems? As I understand ...
6
votes
2answers
504 views

Was the Higgs mass correctly predicted by asymptotic safety of gravity?

This paper was published in Phys Lett B in 2009, and predicted the Higgs mass to be 126 GeV based on the asymptotic safety of gravity. Is this prediction taken seriously by the theory community, or is ...
0
votes
1answer
441 views

What is the relationship between the Higgs field and quarks?

I have some difficulty considering the relative size of each and the meaning behind the shape of Higgs boson. I ask relating to the structures of both the Higgs field and quarks. How is it that the ...
5
votes
3answers
296 views

Higgs Boson: The Big Picture

First, please pardon the ignorance behind this question. I know a fair amount of math but almost no physics. I'm hoping someone can give me a brief "big picture" explanation of how physicists were ...
2
votes
2answers
301 views

Some very basic questions on the Higgs Boson

What exactly is a boson? Is the Higgs boson the cause of gravity or a result of it? Does the collision of particles at the LHC create a gravity field or waves or somehow interact with the gravity ...
9
votes
0answers
200 views

Relation among anomaly, unitarity bound and renormalizability

There is something I'm not sure about that has come up in a comment to other question: Why do we not have spin greater than 2? It's a good question--- the violation of renormalizability is linked ...
1
vote
1answer
211 views

Lepton masses in the Standard Model

Some simple questions regarding leptonic masses in the Standard Model (SM): Why there is not an explicit mass term in addition to the effective mass term that arises from the Yukawa terms after ...
2
votes
1answer
294 views

Is Connes model a composite Higgs in disguise?

Most of the 5-dimensional Higgs models can be seen, if I understand correctly, as models where the Higgs is a composite. Now, is this true for Connes models? It is a model of extra dimensions too, ...
2
votes
1answer
286 views

Higgs potential

The potential for the Higgs field is standard a quartic one (Mexican hat). Is this done for simplicity or are there fundamental reasons for this choice? I can imagine further contributions to this ...
5
votes
2answers
190 views

What has been measured at the Higgs experiment and what do we know now?

Explained at the level of a 5$^{\text {th}}$ semester physics student (i.e. pre QFT, but far beyond the level of a news article for non-physicists, which avoids all details and only deals in ...
4
votes
3answers
306 views

Does Standard Model confirm that mass assigned by Higgs Mechanism creates gravitational field?

I am not comparing passive gravitational mass with rest inertial mass. Is there an evidence in Standard Model which says that active gravitational mass is essentially mass assigned by Higgs mechanism. ...
0
votes
1answer
268 views

How to calculate Rest Mass practically with Standard Model?

With relativistic physics, we can apply force to see resistance against acceleration. It'd give us relativistic mass and we have well established formula to get to the Rest Mass as long as we know the ...