Derived Properties In Particle Physics

It is customary to assume more properties of gauge theories than is necessary to produce all of their properties. Some of those assumptions can be derived, including CP invariance.

We revisit the emergence of a Yang-Mills symmetry in theories with massless spin 1 particles from fundamental physical properties of scattering amplitudes. In the standard proofs, some symmetry and reality properties of the coupling constants in three-point amplitudes are assumed. These properties cannot be justified using only three-point amplitudes but we show that they arise as consequences of the consistent factorization of four-particle amplitudes, for particular choices of the particle basis. This applies to self-interactions of massless spin 1 particles and also to their interactions with spin 0 and 1/2 particles. CP invariance is a derived property, not an additional assumption. The situation for gravity interactions is analogous and it is dealt with in the same fashion.

Renato M. Fonseca, Clara Hernandez-Garcia, Javier M. Lizana, Manuel Perez-Victoria, "Gauge theories from scattering amplitudes with minimal assumptions" arXiv:2511.21664 (November 26, 2025).

Two Tully-Fischer Relations Linked

 

The Baryonic Tully - Fisher relation (BTFR) links the baryonic mass of galaxies to their characteristic rotational velocity and has been shown to with remarkable precision across a wide mass range. 

Recent studies, however, indicate that galaxy clusters occupy a parallel but offset relation, raising questions about the universality of the BTFR. 

Here, we demonstrate that the offset between galaxies and clusters arises naturally from cosmic time evolution. Using the evolving BTFR derived from the Nexus Paradigm of quantum gravity, we show that the normalization of the relation evolves as an exponential function of cosmic time, while the slope remains fixed at ∼4. This provides a simple and predictive framework in which both galaxies and clusters obey the same universal scaling law, with their apparent offset reflecting their different formation epochs. Our results unify mass-velocity scaling across five orders of magnitude in baryonic mass, offering new insights into cosmic structure formation.

Stuart Marongwe, Stuart Kauffman, "The Evolving Baryonic Tully Fisher Relation: A Universal Law from Galaxies to Galactic Clusters" arXiv:2511.20188 (November 25, 2025).

There is a tight link between the amount of ordinary matter in a galaxy and its rotation speed over many orders of magnitude. This empirical relationship arises naturally from the phenomenological gravity modification known as MOND, without dark matter.

The same relationship holds true for galaxy clusters, but it is shifted from the relationship for galaxies.

The authors propose a theory that would unify both of these relationships. It works, but it isn't terribly convincing but there are a multitude of ways that galaxies and galaxy clusters differ which could give rise to the shift in the relationship that is observed.

Closely related issues are discussed at the latest post at Triton Station.

JUNO Hype And Reality

A new neutrino physics experiment published a preprint with new measurements of neutrino oscillation constants. The new equipment works to high precision and will help fine tune the exact values of some the least precisely known experimentally measured parameters in the Standard Model of Particle Physics. 

This is interesting to people who follow particle physics closely. It is also scientifically important. But honestly, it isn't that interesting to the average person with only a general interest in science.

But, Rory Harris at Live Science in a fit a yellow journalism in the science world, writes a story containing all sorts of nonsense about JUNO revealing beyond the Standard Model physics, as well as the usual, misleading blather about CP violation experimentation answering questions about the baryon asymmetry of the universe (which this experiment does not do).