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I have came across this recent development in the LHC:

Breakthrough at the Large Hadron Collider: https://www.youtube.com/watch?v=qR6P0aRqYf8

Leptoquarks and leptons - quarks unification: https://en.wikipedia.org/wiki/Leptoquark

Leptoquarks (LQs) are hypothetical particles that would interact with quarks and leptons. Leptoquarks are color-triplet bosons that carry both lepton and baryon numbers. Their other quantum numbers, like spin, (fractional) electric charge and weak isospin vary among theories.

Does this mean that we are heading for a strong-EM forces unification?

Is the Electron after all coupled to the individual quarks in the nucleus via these new boson? And therefore new unifying force discovered?

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    $\begingroup$ I would recommend changing the word "discovered" to "suggested". Currently the results are 3.1 $\sigma$ and the threshold to claim "discovery" is 5 $\sigma$ $\endgroup$
    – Dale
    Mar 27, 2021 at 20:16
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    $\begingroup$ We are headed to no such place. 3.1 σ does not mean only one in a thousand such announcements fail to pan out! $\endgroup$ Mar 28, 2021 at 0:22
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    $\begingroup$ For reference: the paper from CERN, Test of lepton universality in beauty-quark decays $\endgroup$ Mar 28, 2021 at 11:33
  • $\begingroup$ Another news reference on the latest exciting development of the LHCb experiment: trtworld.com/life/… $\endgroup$
    – Markoul11
    Mar 30, 2021 at 13:01
  • $\begingroup$ Also reading the above arxiv paper linked by @ThomasFritsch of the experiment, it is my understanding that the measured discrepancy is around 15.4% more electron-positron pairs are produced than muon-antimuon pairs. $\endgroup$
    – Markoul11
    Mar 30, 2021 at 13:26

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Let us clear up the background:

Mainstream particle physics has the standard model , a Quantum Field Theoretical model ( QFT) which not only fits the plethora of existing data , but also is mostly very successful in predicting . It is based on unifying strong , weak, and electromagnetic forces mathematically. It is supposed at very high energy that the weak and electromagnetic are unified in one force, and there is a symmetry breaking that separates the weak from the electromagnetic carriers. In the SM at the energies we have attained all the forces have their own carriers.

Does this mean that we are heading for a strong-EM forces unification?

There are the Grand Unified Theories , that try in the same way to unify weak elecgtromagnetic and strong at even higher energies, with symmetry breaking creating the seen at low energy forces.

These new theories are proposed to solve discrepancies with the standard model and observations, that still exist, for example, in using the standard model to fit cosmological data. All new theories have to reduce to the the standard model at low energies.

Grand unified theories are proposed for high energies, and will break down to the standard model at lower energies.

A Grand Unified Theory (GUT) is a model in particle physics in which, at high energies, the three gauge interactions of the Standard Model comprising the electromagnetic, weak, and strong forces are merged into a single force. Although this unified force has not been directly observed, the many GUT models theorize its existence. If unification of these three interactions is possible, it raises the possibility that there was a grand unification epoch in the very early universe in which these three fundamental interactions were not yet distinct.

Here is how the proton might decay in this type of theories.

su5gut

In SU(5) Gut model.

The X is the carrier of all forces before symmetry breaking energies. As we have not observed a proton decay, this means there is very small probability to see the proton decay in our experiments, and estimate the X. Again, for low energies the model symmetry has to break down to the standard model, to be able to fit the existing data.

Here is how the Big Bang cosmological time line uses symmetry breaking:

timelinBB

Is the Electron after all coupled to the individual quarks in the nucleus via these new boson? And therefore new unifying force discovered?

It is always possible for the electron to couple to quarks within the standard model, no new forces are needed. The mass of the new bosons in GUT theories is so large, that evaluating the probabilities of mediation would lead to practically zero probability. One could calculate the interaction of the electrons to the quarks with the weak force too, but the W and Z have such high mass that it is useless to do the calculation.

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Well, the video itself is actually quite a bit more cautious than your enthusiastic endorsement/questioning. The signal at the LHCb is at 3 sigma, which means a 1 in 1000 chance of a positive evidence. Generally speaking, physicists don't get excited till they hit 5 sigma, which is 1 in 10 million chance.

The suggested explanation of a leptoquark are from GUTs, such as the Pati-Salam model or the SU(5) or SO(10) GUTs. Given that the odds have been steadily increasing it's grounds for cautious optimism but I wouldn't just celebrate just yet.

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    $\begingroup$ I am no experimental particle physicist, but isn't $3\sigma$ representing 997 in 1000 of positive evidence? $\endgroup$
    – oliver
    Mar 27, 2021 at 20:48
  • $\begingroup$ @oliver: I'm quoting the video... $\endgroup$ Mar 27, 2021 at 20:54
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    $\begingroup$ @oliver I haven't watched the video so I don't know exactly how they phrase it. But the correct interpretation would be that it is 1/1000 probability for the data to exhibit a positive signal to the observed extent under the assumption of a null hypothesis. I.e. it is an unlikely observation if the signal were not "true". $\endgroup$
    – hiccups
    Mar 27, 2021 at 23:57
  • $\begingroup$ @hiccups: Well, I watched it, and I quoted it - after all the OP was asking people to watch it. The way you are phrasing it would be consistent for a peer-reviewed scientific report, which this answer certainly isn't, and nor was the OP asking for one. Moreover, I would expect the authors of such a rigorously researched scientific report to dispense with acknowledging 'under the assumption of a null hypothesis', simply because they would take their audience to be already familiar with that proviso. After all, simply because the integral from calculus is defined in terms of a limit does not ... $\endgroup$ Mar 28, 2021 at 0:10
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    $\begingroup$ When the meaning of a particular jargon is questioned, I typically prefer to clarify it. I don't think doing so would cause any irritation or exasperation :) $\endgroup$
    – hiccups
    Mar 28, 2021 at 0:29

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