Each possible interpretation will lead to additional predictions, which (with time) can be tested. It is not like pure fitting, where additional epicycles can be added at your whims. With little certain data available, many theoretical models can be proposed; with more data and analysis most of them will die.

I remember the discovery of monojets in the 80's, just after W and Z was found. Many models were suggested, but (if I remember correctly) after a while they were all ruled out; the observations were simply not consistent with other results in any inventible way.

The Standard Model is a rather tightly knit structure, it will not be that easy to extend it without violating established results.  If the particle(s) really exist, I am confident many if not most of their properties can be sorted out over time. But it will take more than 2 days and 18 papers to converge on an accepted interpretation.

Anyway, this looks like a very nice xmas gift to elementary particle physics!

The Standard Model of particle physics is our best conventional model for what is going on at subatomic scales.

However, here are a few well-known problems with the SM.

1. The Standard Model is primarily a heuristic model with 26-30 fundamental parameters that have to be “put in by hand”. 

2. The Standard Model did not and cannot predict the masses of the fundamental particles that make up all of the luminous matter that we can observe. QCD still cannot retrodict the mass of the proton without considerable fudging, and even then it is only good to within 5%.  As for retrodicting the mass of the electron, the SM cannot even make an attempt.

3. The Standard Model did not and cannot predict the existence of the dark matter that constitutes the overwhelming majority of matter in the cosmos. The Standard Model describes heuristically the "foam on top of the ocean".

4. The vacuum energy density crisis clearly suggests a fundamental flaw at the very heart of particle physics. The VED crisis involves the fact that the vacuum energy densities predicted by particle physicists (microcosm) and measured by cosmologists (macrocosm) differ by up to 120 orders of magnitude (roughly 10^70 to 10^120, depending on how one ‘guess-timates’ the particle physics VED).

5. The conventional Planck mass is highly unnatural, i.e., it bears no relation to any particle observed in nature, and calls into question the foundations of the quantum chromodynamics sector of the Standard Model.

6. Many of the key particles of the Standard Model have never been directly observed. Rather, their existence is inferred from secondary, or more likely, tertiary decay products. Quantum chromodynamics is entirely built on inference, conjecture and speculation. It is too complex for simple definitive predictions and testing.

7. The standard model of particle physics cannot include the most fundamental and well-tested interaction of the cosmos: gravitation, i.e., general relativity.

Robert L. Oldershaw

http://www3.amherst.edu/~rloldershaw

Discrete Scale Relativity/Fractal Cosmology

Personally, I think that Gell-Mann's original intuition: that quark theory was an artificial construct that provides a model for reproducing observations but was not what was actually going on in nature, was correct. I also think that the standard model does not need to be "extended", but rather that it needs to be replaced by a completely new paradigm. I may be the only person on the planet with the chutzpah to promote such a preposterous idea, but I think this will turn out to be verified in the long run.

I apologize to those who get upset by these troubling remarks.