Constrains on experimental space and parameters

[jake jot]

There is this argument that any new forces of nature or any new interactions would have very small gap of space left in the experimental space or parameter. The argument being that for every force, there is a particle and a field, and virtual particles. And the virtual particles can affect behavior of particles (for example, the electron moment of the muon) or mass of the Higgs. Can anyone give a reference of exactly this thing about the constrains and the small gap left for new forces of nature or field?

And the reason I post this in BSM and not at the High Energy, Nuclear, Particle Physics subforum which I initially planned to was asking the second question.

What are physicists creative ways around the constrains or exceptions like some new laws in physics where there can be new forces that won't affect the constrains on experimental space? Lisa Randall RS1 or RS2 talks about the Hierarchy Problem being solved by separating the gravity brane and weak brane or Planck mass and the gravitational mass. Could it be something like it? References pls. Thank you.

 

[jake jot]

I tried to search answer and here is what I found out so far:

The standard model of particle physics is based on the three known forces and is validated within experimental errors, except for some specific experimental observations, as for example baryon asymmetry BUT research is going on beyond the standard model, theoretically, and the new theories do involve new forces. For example GUTs (references in the link) were of the first proposals . The whole point of continuing particle research experiments is to find out if these new theories that embed the standard model for lower energies, are correct.

The small gap left for new forces of nature or field? can be found in the proposals for these new theories. I do not think a separate study would exist.

Really? The small gap is for GUT forces? But if the proton radius problem (maybe solved already) or other none-GUT forces were found. It should be within the gap too? What exactly is the gap in energies? Perhaps some illustrations?

Googling about GUT. I read this: " The supposition that the electric charges of electrons and protons seem to cancel each other exactly to extreme precision is essential for the existence of the macroscopic world as we know it, but this important property of elementary particles is not explained in the Standard Model of particle physics. ".

Without using GUT. Any way to explain it?

 

[mitchell porter]

If I understand the question correctly, you're asking what possibilities remain for new fundamental forces or fields, given experimental constraint. This is extremely broad, the search for new things is a huge part of experimental particle physics. Many possibilities are not categorically ruled out, but rather there are constraints on their properties, e.g. if there is a new kind of massive W-like boson, it must have at least a certain mass, to have gone undetected so far. You can see some constraints of this kind at Particle Data Group, under "Hypothetical particles and constraints".

 

[jake jot]

If I understand the question correctly, you're asking what possibilities remain for new fundamental forces or fields, given experimental constraint. This is extremely broad, the search for new things is a huge part of experimental particle physics. Many possibilities are not categorically ruled out, but rather there are constraints on their properties, e.g. if there is a new kind of massive W-like boson, it must have at least a certain mass, to have gone undetected so far. You can see some constraints of this kind at Particle Data Group, under "Hypothetical particles and constraints".

I mean, is it not the mass of the Higgs or other masses (what exactly) were the results of effects of virtual particles of all existing particles and forces? Such that any new particles can affect it (even forces outside of GUT)? I just want details of this very sensitive balance. Or maybe the mass of the Higgs or others already include all contribution from all unknown forces of nature?

 

[jake jot]

I mean, is it not the mass of the Higgs or other masses (what exactly) were the results of effects of virtual particles of all existing particles and forces? Such that any new particles can affect it (even forces outside of GUT)? I just want details of this very sensitive balance. Or maybe the mass of the Higgs or others already include all contribution from all unknown forces of nature?

I found the article about it.

Naturalness and the Standard Model | Of Particular Significance (profmattstrassler.com)

This paragraph seems to say many new physics are possible:

But that’s not all. To this we have to add other contributions, shown in the second row of Figure 5, which come from physical phenomena that we don’t yet know anything or much about, physics that does not directly appear in the Standard Model at all. [Technically, we absorb these effects from unknown physics into parameters that define the Standard Model’s equations, as inputs to those equations; but they are inputs, rather than something we calculate, precisely because they’re from unknown sources.] In addition to effects from quantum fluctuations of known fields with even higher energies, there may also be effects from

• the quantum mechanics of gravity,
• heavy particles we’ve not yet discovered,
• forces that are only important at distances far shorter than we can currently measure,
• other more exotic contributions from, say, strings or D-branes in string theory or some other theory like it,
• etc.,

some of which may depend, directly or indirectly, on the Higgs field’s value. I’ve drawn these unknown effects in red; note that these curves are pure guesswork. We don’t know anything about these effects except that they could exist (and the gravity effects definitely exist), and that some or all of them could be really big… as big as or bigger than the ones we know about in the upper row. In principle, all these unknown effects could be zero — but that wouldn’t resolve the naturalness problem, as we’ll see, so presumably they’re not all zero.

But this paper in the references says:

rpp2020-rev-standard-model.pdf (lbl.gov)

"Electroweak Model and Constraints on New Physics"

It's written in super dense mathematics. So would appreciate it if someone can at least give a brief summary or punchline what kinds of new physics were constrained by the Electroweak Model.