arXiv subjects

Noah Bray-Ali

Publications and source records attributed to Noah Bray-Ali.

12 recordsLinked to original sources

arXiv2026

Dark Matter Halo Axions Shift Hadron Collider $W$ Mass

The 2026 measurement of the $W$ mass by CMS at the Large Hadron Collider disagrees sharply with the earlier and more precise measurement by CDF at the Tevatron, yet the CMS result seems to agree rather well with the standard model value. A similar fact pattern is identified for two other observables that have been the subject of recent intense interest: the strong coupling constant and the leading-order hadronic contribution to the muon magnetic dipole moment. Using a straightforward proper-time analysis of the leading-order hard gluon corrections to the $W$ boson production amplitude from quark-antiquark annihilation in high-energy hadron collisions, it is suggested that the CDF experiment has discovered a new phenomenon beyond the standard model and that the CMS measurement confirms this discovery: A coherent dynamic background axion field created by axions from the local dark matter halo of the galaxy couples to the hard virtual gluon within the luminous four-volume at the interaction point inside the collider detector and this axion-gluon coupling shifts the $W$ mass determination linearly in the product of the beam width and the bunch length.

hep-ph↗

arXiv2026

0.5 eV QCD Axion Cosmology

The best available determination of the present expansion rate of the universe using late-universe observations, by the SH0ES collaboration in 2025, differs by more than seven standard deviations from the value of the Hubble constant determined by the Planck collaboration in 2018 using early-universe observations and the standard cold dark matter cosmology with cosmological constant, a discrepancy known as the Hubble tension. Within a spatially flat, isotropic, and homogeneous expanding-universe solution of the field equations of general relativity with cosmological constant, the SH0ES value for the Hubble constant implies roughly twice as many baryons as the standard cosmology, provided that one retains the Planck values for the energy density of cold dark matter in the present universe and for the cosmological constant. A novel cosmology is proposed --- in terms of cooling dark matter made of quantum chromodynamic (QCD) axions with present number density six times that of the photons in the cosmic microwave background --- which realizes this straightforward, doubled-baryons scenario for resolving the Hubble tension.

hep-ph↗

arXiv2026

Determining $G$ with Laser Spectroscopy to 38 ppb

A precision measurement is proposed to determine, in a couple hours of integration time, the axion Compton frequency using a modest power (3 mW) tunable external-cavity diode laser at 2458 nm as input to drive a free-space table-top Mach-Zehnder interferometer whose sensing arm passes the expanded beam-waist ($3~{\rm mm}$) light beam through a $1~{\rm T}$ strong, $40~{\rm cm}$ long dipole magnetic field created by a custom-built permanent-magnet assembly with a large but achievable ($6~{\rm mm}$) gap between poles. As the laser frequency is slowly modulated at 1 kHz through a 65 MHz wide window that is well within the 30 GHz fine-tuning range of the laser, a small but readily observable modulation appears in the dark-port optical power of the dark-fringe phase-locked interferometer due to photons converting into axions within the light beam as it passes through the magnetic field. Measuring the axion Compton frequency, $ν_A\approx{\rm 122~THz}$, where the dark-port power modulation peaks, to within the line-width of the laser, $Δν_A=1~{\rm MHz}$, then determines $G$ to 38 ppb, a roughly 600-fold improvement, through a relation between $ν_A$ and $G$, involving $h$, $c$, and nucleon masses.

hep-ph↗

arXiv2023

Spontaneous Mutations from Terahertz Proton Tunneling

Protons in the gap between base pairs of the double helix store the code of life by breaking the chiral symmetry that swaps the sense strand with its complementary partner. When these hydrogen bonds break during replication and transcription, pairs of protons switch sides restoring chiral symmetry and destroying genetic information. Using time-independent second-order perturbation theory, we show that the observed rate of such spontaneous mutations follows in the sudden approximation for bond breaking provided protons in bonds between bases tunnel across the gap with terahertz frequencies.

physics.bio-ph↗

arXiv2019

Holographic Code Rate

Holographic codes grown with perfect tensors on regular hyperbolic tessellations using an inflation rule protect quantum information stored in the bulk from errors on the boundary provided the code rate is less than one. Hyperbolic geometry bounds the holographic code rate and guarantees quantum error correction for codes grown with any inflation rule on all regular hyperbolic tessellations in a class whose size grows exponentially with the rank of the perfect tensors for rank five and higher. For the tile completion inflation rule, holographic triangle codes have code rate more than one but all others perform quantum error correction.

quant-ph↗

arXiv2017

Standard Temperature and Pressure Superconductivity

Superconductivity at standard temperature and pressure is far from the extreme conditions where new fundamental laws of physics are expected to arise. Yet it is widely believed that the Landau-Ginzburg-Wilson-Fisher paradigm of broken symmetry and renormalization does not give a satisfactory account of the phenomenon. Almost a decade ago, we used the Bardeen-Cooper-Shrieffer wavefunction to show that superconductors have topological order. Here we report progress using topological order to look for standard temperature and pressure superconductivity.

cond-mat.str-el↗

arXiv2013

Direct observation of the Mott gap in strontium iridate with a scanning tunneling microscope

The single-layer Mott insulator strontium iridate Sr$_2$IrO$_4$ was studied using a scanning tunneling microscope. This measurement technique is unique due to the transport properties of this Mott insulator allowing tunneling measurements to be performed, even at cryogenic temperatures. We obtained high-resolution images of the sample surface and the differential tunneling conductance at different cryogenic temperatures. The differential conductance is a direct measurement of the local electronic density of states which provided an insulating gap consistent with optical conductivity, angle resolved photoemission spectroscopy and resonant inelastic x-ray scattering (RIXS) experiments. The observed widths of these features is broader than predicted by the Slater approximation and narrower than predicted by dynamical mean field theory. Additionally, the observed density of states due to magnetic fluctuations is found in the derivative of the differential conductance and is consistent with results from Raman scattering and RIXS. At low temperatures, additional low-energy features were observed, suggesting a change in the dispersion of the collective magnetic excitations, which is consistent with the magnetic susceptibility.

cond-mat.str-el↗

arXiv2012

Chern numbers hiding in time-of-flight images

We present a technique for detecting topological invariants -- Chern numbers -- from time-of-flight images of ultra-cold atoms. We show that the Chern numbers of integer quantum Hall states of lattice fermions leave their fingerprints in the atoms' momentum distribution. We analytically demonstrate that the number of local maxima in the momentum distribution is equal to the Chern number in two limiting cases, for large hopping anisotropy and in the continuum limit. In addition, our numerical simulations beyond these two limits show that these local maxima persist for a range of parameters. Thus, an everyday observable in cold atom experiments can serve as a useful tool to characterize and visualize quantum states with non-trivial topology.

cond-mat.quant-gas↗

arXiv2010

Bilayer Quantum Hall Ferromagnet in a Periodic Potential

The bilayer quantum Hall system at a total filling of $ν_T=1$ has long resisted explanation in terms of a true counterflow superfluid, though many experimental features can be seen to be "almost" that of a superfluid. It is widely believed that quenched disorder is the root cause of this puzzle. Here we model the nonperturbative effects of disorder by investigating the $ν=1$ bilayer in a strong periodic potential. Our model assumes that fermions are gapped and real spins are fully polarized, and concentrates on the pseudospin variable (the layer index), with the external potential coupling to the topological (Pontryagin) density of the pseudospin. We find that as the potential strength increases, there are ground state transitions in which the topological content of the pseudospin configuration changes. These transitions are generically weakly first-order, with a new quadratically dispersing mode (in addition to the linearly dispersing Goldstone mode) sometimes becoming nearly gapless near the transition. We show that this leads to strong suppressions of both the Kosterlitz-Thouless transition temperature and the interlayer tunneling strength, which we treat perturbatively. We discuss how these results might extend to the case of true disorder.

cond-mat.str-el↗

arXiv2009

Fractal dimension and threshold properties in a spatially correlated percolation model

We consider the effects of spatial correlations in a two-dimensional site percolation model. By generalizing the Newman-Ziff Monte Carlo algorithm to include spatial correlations, percolation thresholds and fractal dimensions of percolation clusters are obtained. For a wide range of spatial correlations, the percolation threshold differs little from the uncorrelated result. In contrast, the fractal dimension differs sharply from the uncorrelated result for almost all types of correlation studied. We interpret these results in the framework of long-range correlated percolation.

cond-mat.dis-nn↗

arXiv2008

Subarea law of entanglement in nodal fermionic systems

We investigate the subarea law scaling properties of the block entropy in bipartite fermionic systems which do not have a finite Fermi surface. It is found that in gapped regimes the leading subarea term is a negative constant, whereas in critical regimes with point nodes the leading subarea law is a logarithmic additive term. At the phase boundary that separates the critical and non-critical regimes, the subarea scaling shows power-law behavior.

cond-mat.str-el↗

arXiv2008

Scaling Analysis and Application: Phase Diagram of Magnetic Nanorings and Elliptical Nanoparticles

The magnetic properties of single-domain nanoparticles with different geometric shapes, crystalline anisotropies and lattice structures are investigated. A recently proposed scaling approach is shown to be universal and in agreement with dimensional analysis coupled with an assumption of {\em incomplete} self-similarity. It is used to obtain phase diagrams of magnetic nanoparticles featuring three competing configurations: in-plane and out-of-plane ferromagnetism and vortex formation. The influence of the vortex core on the scaling behavior and phase diagram is analyzed. Three-dimensional phase diagrams are obtained for cylindrical nanorings, depending on their height, outer and inner radius. The triple points in these phase diagrams are shown to be in linear relationship with the inner radius of the ring. Elliptically shaped magnetic nanoparticles are also studied. A new parametrization for double vortex configurations is proposed, and regions in the phase diagram are identified where the double vortex is a stable ground state.

cond-mat.str-el↗