Questions tagged [standard-model]
A model of the basic particles and forces featuring six quarks, three charged leptons, three massless neutral leptons and four fundamental force carrying bosons. The twelve fermions are arranged into three generations, while the bosons serve to explain the electromagnetic interaction plus the strong and weak nuclear forces (and the Higgs mechanism). Do NOT use this tag for the standard model of cosmology, etc..
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Can glueballs and bosons survive indefinetely in space (forming structures)?
I have been recently interested in looking for possible structures (ranging from clumped structures like "stars" to diffuse clouds of gas or halos) made from standard model-particles other ...
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Matrix element including weak currents
If a $\overline{B^0}$ meson decays into $D^+$, $e^-$ and $\overline{\nu}_e$ we have a matrix element $$\langle{D^+ \, e^- \, \overline{\nu}_e |\, (\overline{c_L} \gamma^{\mu} b_L) \, (\overline{e_L} \...
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How to interpret a branching fraction diagram?
I'm confused as to how can I (student in master 1 class of particle physics) interpret such diagram:
Where $q^2 = m^2(l^+l^-)$. I understand that the y axis represents the variation of the ...
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Is the Higgs sector in the Standard Model also asymptotically free?
I have always thought that the Higgs sector, which is $\phi^4$ theory in essence, is not asymptotically free.
However, I ran into the following statement from this paper:
The standard model is, in ...
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$W$ and $B$ bosons when choosing a different minimum of the Higgs doublet
When comparing the experimental phenomenology with the standard model, one usually takes a combination of the $W^a_\mu$ and $B_\mu$ gauge bosons to obtain the physically observable ones ${W^+}_\mu$, ${...
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Measurable effects of the global structure of the SM
It is known that the Lie algebra of the SM is
$$
\mathfrak{su}(3)\oplus \mathfrak{su}(2)\oplus \mathbb{R}\,,
$$
so that the Lie group is
$$
G_{\text{SM}} = \dfrac{SU(3)\times SU(2) \times U(1)}{\Gamma}...
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Would it be possible to build the standard model in terms of Joos-Weinberg spinors?
The Joos-Weinberg equation describes spinors of arbitrary spin. Could we replace all of the existing matter fields (scalar, fermionic, gauge, Rarita Schwinger, etc.) with JW spinors and still end up ...
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Seeking references for giving geometrical interpretations of electromagnetism and the nuclear forces
From this thread, we have the following comment:
To further blur the line, it is possible to give geometrical interpretations of electromagnetism and the nuclear forces, such that they appear to be ...
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A confusion: Why are composite bosons possible?
I am not a physicist, but trying to understand the standard model to some extent. My understanding is that the essential property of Bosons and Fermions is that two distinct Bosons can occupy the same ...
- 1,772
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Do we understand chemistry from particle physics?
My chemistry knowledge is of a high-school level. In high-school, the properties of atoms were mostly presented as empirical phenomena. We learned some physical principles such as the idea that ...
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Renormalizability of Quantum Gravity
At the end of chapter 6 on p. 210 in David's Griffiths' book Introduction to Elementary Particle Physics he says that 't Hooft proved that all gauge theories are renormalizable. I have also read ...
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Custodial symmetry of the standard model symmetry group $SU(2)_L \times SU(2)_R$
I am studying the standard model including the Higgs sector and electroweak interactions. Here, all of my terms have their usual meanings. Therefore my symmetry group is $SU(2)_L \times SU(2)_R \times ...
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Understading dimensions in quark bilinears
I have encountered myself with the following definition for $\pi$-fields as quark bilinears:
$$
\pi^a = i\bar{q}\tau^a \gamma_5 q \ ,\quad\text{with }\ q = \left(\begin{array}{c}u\\d\end{array}\right) ...
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Different representations of the Yukawa interaction
during studying Yukawa sector of the SM, I got confused with different reps of the Yukawa interaction.
First, this is what I am familiar with(let me show only electron mass term):
$$y_e \bar{L}_e H ...
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Why can't we insist that the strong interactions must preserve $CP$?
I'm having some trouble wrapping my head around the strong $CP$ problem. I know that the non-trivial vacuum structure of QCD induces the topological theta term in the strong sector of the SM, which is ...
