Determining the top quark mass precisely is quite important to evaluating many theoretical proposals regarding the source of the experimentally measured mass constants in the Standard Model (equivalently, the pattern to the Higgs Yukawas).
A new proposal would largely eliminate one of the main sources of systemic error in that measurement, which currently has a combined uncertainty from all sources in an inverse error weighted global average of ± 300 MeV or so. The W boson mass is known to about ± 12 MeV. And, the sources of uncertainty when measuring their masses in collider experiments are highly correlated. So, if the ratio of the top quark mass to the W boson mass can be determined precisely, then the uncertainty in the top quark mass measurement can be greatly reduced.
The top quark mass is a key parameter of the standard model, yet measuring it precisely at the Large Hadron Collider (LHC) is challenging. Inspired by the use of standard candles in cosmology, we propose a novel energy correlator-based observable, which directly accesses the dimensionless quantity 𝑚(𝑡)/𝑚(𝑊). We perform a Monte Carlo study to demonstrate the feasibility of the top mass extraction from Run 2, 3, and High-Luminosity LHC datasets. Our resulting 𝑚(𝑡) can be defined in a well-controlled short-distance mass scheme and exhibits remarkably small uncertainties from nonperturbative effects, as well as insensitivity to parton distribution functions, outlining a roadmap for a record precision measurement at the LHC.
Jack Holguin, et al., "Using the 𝑊 Boson as a Standard Candle to Reach the Top: Calibrating Energy-Correlator-Based Top Mass Measurements" Phys. Rev. Lett. 134, 231903 (13 June, 2025).
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A Lattice Physics Approach to Spin-Networks in Loop Quantum Gravity
Noah M. MacKay
In this study, we model a spin-network in loop quantum gravity as a regular tetrahedral lattice, applying lattice physics techniques to study its structure and vertex dynamics. Using the area eigenvalue, , we derive a lattice constant and construct a vertex Hamiltonian incorporating a Lennard-Jones potential, zero-point energy, and simple harmonic oscillations. A foliation approach enforces the Wheeler-DeWitt constraint via locally non-zero Hamiltonians that globally cancel. Graviton-like perturbations (treated here as spin-0 bosons) modify the vertex energy spectrum, with variational analysis suggesting twelve coherent excitations per vertex. This model frames flat spacetime as a graviton-rich lattice while enforcing a Brownian-like stochastic picture for the gravitons, and offers a basis for extension into curved quantum geometries.
Comments: 9 pages (with appendices), 3 figures
using lattice physics techniques on spin-network in loop quantum gravity and Graviton-like perturbations (treated here as spin-0 bosons) flat spacetime as a graviton-rich lattice while enforcing a Brownian-like stochastic picture for the gravitons