# Tag Info

## New answers tagged higgs

1

There is no need of starting with $SU(2)$ symmetry and then extending it to $SU(2)_L\otimes SU(2)_R$. In fact, the moment you write down the Lagrangian, the symmetry is by default $U(2)_L\otimes U(2)_R$ with $U(2)_L$ acting on the left handed quark doublet $(u , d)_L$ and $U(2)_R$ acting on the right handed quark doublet $(u , d)_R$, which can be extended ...

2

Question 1 First of all, when you discuss chiral symmetry spontaneous breaking, you need to assume pure QCD theory. QCD lagrangian with $u-,d-,s-$quarks (they have relatively small masses in compare with $b, t, c$-quarks) has the form  \tag 1 L_{QCD} = \bar{q}_{i}i\gamma_{\mu}D^{\mu}_{ij}q_{j} - \frac{1}{4}G_{\mu \nu}^{a}G^{\mu \nu}_{a} - ...

-3

Another factor here: We build these huge atom smashers because we want a look at things that are normally sealed inside larger particles. The energy is to shatter the box they're in.

87

Isn't the universe full of Higgs bosons, making up the Higgs field? No. In particle physics, it is understood that the underlying (more fundamental) object is the field, not the particles. Particles are excitations of the fields that can be measured, and always carry certain properties like charge, mass, spin etc. The field that you are most familiar ...

3

Ad 1) Yes and no. There are certainly Higgsbosons in the Universe. Everything we can create at the LHC is created in other events too. Cosmic rays can have more energy than the LHC beam, so there will be Higgs bosons for sure, just as an example. The problem is to bring such a sophisticated detector in place, in addition you don't really have the experiment ...

1

I think it's impossible, because you'd break electromagnetism if the spectrum had a single neutral Higgs in a 2HDM. I presume both doublets obtain VEVs such that 8 real dof are supposed to be reduced to 5 dof after EWSB, with 3 dof eaten by massive gauge bosons. But if the Higgs doublets have a single neutral component, one of the charged ones must be ...

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