The Particle Data Group value for the strong force coupling constant is 0.1180 ± 0.0009. This new determination, based upon earlier runs of LHC dijet data and lower energy HERA data, is consistent with the PDG value at the 0.1 sigma level.
The strong force coupling constant is pervasively important in almost all high energy physics calculations, but it known much less precisely (with just one part per 131 parts precision) than most other Standard Model or fundamental physical constants. So, pinning this down more precisely is always big deal.
The beta function that describes how the strong force coupling constant runs with energy scale is an exact theoretical prediction of the Standard Model, with no experimental uncertainties. The conference presentation's confirmation that the strong force coupling constant runs with energy scale just as predicted in the Standard Model, over four orders of magnitude of energy scale, is arguably an even more important confirmation of the Standard Model, because there are fewer experimental confirmations of this in the literature.
In this talk we present a determination of the strong coupling constant αs and its energy-scale dependence based on a next-to-next-to-leading order (NNLO) QCD analysis of dijet production.
Using the invariant mass of the dijet system to probe αs at different scales, we extract a value of αs(mZ) = 0.1178 ± 0.0022 from LHC dijet data.
The combination of various LHC datasets significantly extends the precision and scale reach of the analysis, enabling the first determination of αs up to 7 TeV. By incorporating dijet cross sections from HERA, we further probe αs at smaller scales, covering a kinematic range of more than three orders of magnitude. Our results are in excellent agreement with QCD predictions based on the renormalization group equation, providing a stringent test of the running of the strong coupling across a wide energy range.
João Pires, "Precision determination of αs from Dijet Cross Sections in the Multi-TeV Range" arXiv:2507.01670 (July 2, 2025) (Contribution to the 2025 QCD session of the 59th Rencontres de Moriond).
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Dipolar dark matter theory based on a non-Abelian Yang-Mills field
Authors: Luc Blanchet, Emeric Seraille
Abstract: Most theories that attempt to reproduce the Modified Newtonian Dynamics (MOND) phenomenology for dark matter at galactic scales rely on ad hoc free functions, preventing them from being regarded as fundamental. In this work, we present a new theory that reproduces MOND, built on a supposed to be fundamental Yang-Mills gauge field based on SU(2), with a gravitational coupling constant, and emerging in a low-acceleration regime, below the MOND acceleration scale. The gauge field plays the role of the internal force in the dipolar dark matter (DDM) model. We discuss how certain solutions of this theory recover the deep MOND regime without introducing arbitrary functions in the action. Within this framework, the MOND phenomenology appears to be due to the existence of a new sector of particle physics. △ Less
Submitted 3 July, 2025; originally announced July 2025.
Comments: Contribution to the 2025 Gravitation session of the 59th Rencontres de Moriond, 4 pages
Ashtekar variables re-express gravity itself as an SU(2) gauge field
perhaps this is a way to get MOND
I saw it and bookmarked it. I may or may not read it at a more in depth level.
maybe mitchell porter could you do away with dark matter using just SU(2) gauge field in Ashtekar variables
Article
Published: 21 May 2025
Unexpected clustering pattern in dwarf galaxies challenges formation models
Ziwen Zhang, Yangyao Chen, Yu Rong, Huiyuan Wang, Houjun Mo, Xiong Luo & Hao Li
Nature volume 642, pages 47–52 (2025)Cite this article
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Abstract
The galaxy correlation function serves as a fundamental tool for studying cosmology, galaxy formation and the nature of dark matter. It is well established that more massive, redder and more compact galaxies tend to have stronger clustering in space1,2. These results can be understood in terms of galaxy formation in cold dark matter (CDM) halos of different mass and assembly history. Here we report an unexpectedly strong large-scale clustering for isolated, diffuse and blue dwarf galaxies, comparable to that seen for massive galaxy groups but much stronger than that expected from their halo mass. Our analysis indicates that the strong clustering aligns with the halo assembly bias seen in simulations3 with the standard ΛCDM cosmology only if more diffuse dwarfs formed in low-mass halos of older ages. This pattern is not reproduced by existing models of galaxy evolution in a ΛCDM framework4,5,6, and our finding provides clues for the search of more viable models. Our results can be explained well by assuming self-interacting dark matter7, suggesting that such a scenario should be considered seriously.
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