arXiv subjects

Morgan H. Lynch

Publications and source records attributed to Morgan H. Lynch.

16 recordsLinked to original sources

arXiv2025

Hyperbolic recoil and the Unruh effect at CERN-NA63

In this manuscript we examine the high energy channeling radiation data sets from the CERN-NA63 experiment using ultra relativistic synchrotron emission. To incorporate recoil, we examine the standard quasi-classical formalism as well as develop a formalism which includes the Unruh effect by utilizing a hyperbolic recoil acceleration, based on conservation of momentum, in the classical synchrotron trajectory. We also perform an asymptotic radiation time scale analysis which predicts a photon energy threshold, beyond which the Unruh effect dominates. We then compare the classical, quasi-classical, and Unruh synchrotron theories to the data. We find that above threshold, the Unruh effect saturates the spectrum of all data sets.

hep-ph↗

arXiv2025

Experimental observation of a Rindler horizon

In this manuscript we confirm the presence of a Rindler horizon at CERN-NA63 by exploring its thermodynamics induced by the Unruh effect in their high energy channeling radiation experiments. By linking the entropy of the emitted radiation to the photon number, we find the measured spectrum to be a simple manifestation of the second law of Rindler horizon thermodynamics and thus a direct measurement of the recoil Fulling-Davies-Unruh (FDU) temperature. Moreover, since the experiment is born out of an ultra-relativistic positron, and the FDU temperature is defined in the proper frame, we find that temperature boosts as a length and thus fast objects appear colder. The spectrum also provides us with a simple setting to measure fundamental constants, and we employ it to measure the positron mass.

hep-ph↗

arXiv2024

Analysis of the CERN-NA63 radiation reaction data set, assuming the Rindler bath is composed of microscopic black holes

In this manuscript we examine the Unruh-thermalized CERN-NA63 radiation reaction data set from the point of view of a diphoton Rindler bath. Under the assumption that these Hawking-Unruh diphoton pairs are microscopic trans-Planckian black holes, we find the resultant heat capacity describes the measured energy spectrum and is thus a dual description of the data set. Then, employing an n-dimensional Stefan-Boltzmann analysis, we find the power radiated by a black hole in the standard 3+1 spacetime dimensions in complete agreement with the data. Finally, we utilize this power spectrum to directly measure Newtons constant of gravitation.

gr-qc↗

arXiv2023

Accelerated electron thermometer: observation of 1D Planck radiation

We report on the observation of thermal photons from an accelerated electron via examination of radiative beta decay of free neutrons measured by the RDK II collaboration. The emitted photon spectrum is shown to corroborate a thermal distribution consistent with the dynamical Casimir effect. Supported by a robust chi-squared statistic, we find the photons reside in a one-dimensional Planck spectrum with a temperature predicted by the moving mirror model.

nucl-ex↗

arXiv2023

Asymptotic Precision Corrections to Radiation Reaction

The radiative correction to the equation of motion for a moving charged particle is one of the oldest open problems in physics. The problem originates in the emission of radiation by an accelerated charge, which must result in a loss of energy and recoil of the charge, adding a correction to the well-known Lorentz force. When radiation reaction is neglected, it is well known that the dynamics of a charge in an ideal plane-wave field is periodic. Here we investigate the long-time dynamics of a charge in such a field and show that all current models of radiation reaction strictly forbid periodic dynamics. Consequently, we show that under the influence of the external field, the loss of energy to radiation reaction causes particles to accelerate toward an infinite kinetic energy. Such a phenomenon persists even in weak laser fields and puts forward the possibility of testing radiation reaction through long-duration weak-field precision measurements, rather than through strong-field experiments. We further provide numerical examples suggesting realistic conditions for such measurements through the asymptotic frequency shift and energy loss of a charge, which for example can be detected using electron energy spectrometers in ultrafast electron microscopes.

physics.class-ph↗

arXiv2023

Gravitational radiation with kinetic recoil

In this manuscript, we examine the gravitational radiation emitted by binary systems using an Unruh-DeWitt detector coupled to gravitons. Recoil is incorporated into the system via a kinetic energy term in the energy gap of the detector. We find a splitting of the gravitational wave frequency due to the recoil. Implications for the recoil velocity and force are discussed.

gr-qc↗

arXiv2022

Notes on the experimental observation of the Unruh effect

The incorporation of classical general relativity into quantum field theory yields a surprising result -- thermodynamic particle production. One such phenomenon, known as the Unruh effect, causes empty space to effervesce a thermal bath of particles when viewed by an observer undergoing uniformly accelerated motion. These systems will have a Rindler horizon which produces this Unruh radiation at the Fulling-Davies-Unruh temperature. For accelerated charges, the emission and absorption of this radiation will imprint the FDU temperature on photons emitted in the laboratory. Each of these photons will also change the Rindler horizon in accordance with the Bekenstein-Hawking area-entropy law. In this essay, we will discuss these aspects of acceleration-induced thermality which have been experimentally observed in a high energy channeling experiment carried out by CERN-NA63.

gr-qc↗

arXiv2021

Experimental Observation of Acceleration-Induced Thermality

We examine the radiation emitted by high energy positrons channeled into silicon crystal samples. The positrons are modeled as semiclassical vector currents coupled to an Unruh-DeWitt detector to incorporate any local change in the energy of the positron. In the subsequent accelerated QED analysis, we discover a Larmor formula and power spectrum that are both thermalized by the acceleration. Thus, these systems explicitly exhibit thermalization of the detector energy gap at the celebrated Fulling-Davies-Unruh (FDU) temperature. Our derived power spectrum, with a nonzero energy gap, is then shown to have an excellent statistical agreement with high energy channeling experiments and also provides a method to directly measure the FDU temperature. We also investigate the Rindler horizon dynamics and confirm that the Bekenstein-Hawking area-entropy law is satisfied in these experiments. As such, we present the evidence for the first observation of acceleration-induced thermality in a non-analogue system.

gr-qc↗

arXiv2019

Observation of the Stimulated Quantum Cherenkov Effect

As charged particles surpass the speed of light in an optical medium they produce radiation - analogously to the way jet planes surpass the speed of sound and produce a sonic boom. This radiation emission, known as the Cherenkov effect, is among the most fundamental processes in electrodynamics. As such, it is used in numerous applications of particle detectors, particle accelerators, light sources, and medical imaging. Surprisingly, all Cherenkov-based applications and experiments thus far were fully described by classical electrodynamics even though theoretical work predicts new Cherenkov phenomena coming from quantum electrodynamics. The quantum description could provide new possibilities for the design of highly controllable light sources and more efficient accelerators and detectors. Here, we provide a direct evidence of the quantum nature of the Cherenkov effect and reveal its intrinsic quantum features. By satisfying the Cherenkov condition for relativistic electron wavefunctions and maintaining it over hundreds of microns, each electron simultaneously accelerates and decelerates by absorbing and emitting hundreds of photons in a coherent manner. We observe this strong interaction in an ultrafast transmission electron microscope, achieving for the first time a phase-matching between a relativistic electron wavefunction and a propagating light wave. Consequently, the quantum wavefunction of each electron evolves into a coherent plateau, analogous to a frequency comb in ultrashort laser pulses, containing hundreds of quantized energy peaks. Our findings prove that the delocalized wave nature of electrons can become dominant in stimulated interactions. In addition to prospects for known applications of the Cherenkov effect, our work provides a platform for utilizing quantum electrodynamics for applications in electron microscopy and in free-electron pump-probe spectroscopy.

physics.optics↗

arXiv2019

Accelerated-Cherenkov radiation and signatures of radiation reaction

In this manuscript we examine an accelerated charged particle moving through an optical medium, and explore the emission of accelerated-Cherenkov radiation. The particle's reaction to acceleration creates a low-frequency spectral cutoff in the Cherenkov emission that has a sharp resonance at the superluminal threshold. Moreover, the effect of recoil on the radiation is incorporated kinematically through the use of an Unruh-DeWitt detector by setting an energy gap, i.e., the change in electron energy, to the recoil energy of the emitted photon. The simultaneous presence of recoil and acceleration conspire to produce a localized resonance peak in the emission. These theoretical considerations could be used to construct high precision tests of radiation reaction using Cherenkov emission under acceleration.

hep-ph↗

arXiv2018

Temperatures of renormalizable quantum field theories in curved spacetime

In this paper we compute the temperature registered by an Unruh-DeWitt detector coupled to a Hadamard renormalizable quantum field in an arbitrary state, moving along an accelerated trajectory in a curved spacetime. For a massless and conformally invariant field, the generalized expression for the temperature is given by the quadratic sum of the 4-acceleration, Raychaudhuri scalar, and renormalized field polarization. We can further find a novel constraint on the renormalized quantum field polarization in relativistic systems that are in global thermal equilibrium.

gr-qc↗

arXiv2015

Electron decay at IceCube

In this paper we apply the formalism of Accelerated Quantum Dynamics (AQD) to the radiative stopping of highly relativistic electrons in ice. We compute the acceleration profile of the electron along with its lifetime to decay into a muon. The Planckian spectrum of the emitted muon along with the its generalized displacement law are presented and used to quantify the muons properties. The results predict the acceleration-induced decay of electrons at IceCube energies. The signal of electron decay at IceCube manifests itself as an excess of track topologies in an energy window accessible experimentally. This setting has the potential to probe the Unruh effect as well investigate the flavor content of cosmic ray neutrinos.

hep-ph↗

arXiv2015

Accelerated Quantum Dynamics

In this paper we establish a formalism for the computation of observables due to acceleration-induced particle physics processes. General expressions for the transition rate, multiplicity, power, spectra, and displacement law of particles undergoing time-dependent acceleration and transitioning into a final state of arbitrary particle number are obtained. The transition rate, power, and spectra are characterized by unique polynomials of multiplicity and thermal distributions of both bosonic and fermionic statistics. The acceleration-dependent multiplicities are computed in terms of the branching fractions of the associated inertial processes. The displacement law of the spectra predicts that the energy of the emitted particles is directly proportional to the accelerated temperature.

gr-qc↗

arXiv2015

A Theory of Accelerated Quantum Dynamics

The role of acceleration in particle physics can provide an alternative method for probing the properties of quantum gravity. To analyze acceleration-induced processes one utilizes the formalism of quantum field theory in curved spacetime. This quantum theory of fields in classical general relativistic backgrounds has already provided the first insights into the quantum effects of general relativity. By utilizing this formalism to compute acceleration-induced particle physics processes, we can better establish how the dynamics of elementary particles change in non-Minkowskian spacetimes. To analyze these processes, we present a theory of Accelerated Quantum Dynamics (AQD) along with certain observables predicted by the theory.

gr-qc↗

arXiv2014

Acceleration-induced scalar field transitions of n-particle multiplicity

In this paper we calculate the effect of acceleration on the decay and excitation rates of scalar fields into a final state of arbitrary multiplicity. The analysis is carried out using standard field operators as well as an Unruh-DeWitt detector. Using the equivalence of the two methods, we show how to correctly setup the computation and interpret the results in terms of the particle content of the initial and final state Rindler and Minkowski spacetimes. We find the dominant transition pathway, and thus final state multiplicity, is acceleration dependent. The formalisms developed are then used to analyze the electron and muon system. We compute the transition rates and lifetimes for accelerated electrons and muons as well as the branching fractions for muon decay.

gr-qc↗

arXiv2014

Pinning down the cosmic ray source mechanism with new IceCube data

Very recently the IceCube Collaboration has reported an observation of 28 neutrino candidates with energies between 50 TeV and 2 PeV, constituting a 4.1$σ$ excess compared to the atmospheric background. In this article we investigate the compatibility between the data and a hypothesized unbroken power-law neutrino spectrum for various values of spectral index Γ>= 2. We show that Γ~ 2.3 is consistent at the ~ 1.5$σ$ level with the observed events up to 2 PeV and to the null observation of events at higher energies. We then assume that the sources of this unbroken spectrum are Galactic, and deduce (i) an energy-transfer fraction from parent protons to pions, and (ii) a way of discriminating among models which have been put forth to explain the "knee" and "ankle" features of the cosmic ray spectrum. Future IceCube data will test the unbroken power law hypothesis and provide a multi-messenger approach to explaining features of the cosmic ray spectrum, including the transition from Galactic to extragalactic dominance.

astro-ph.HE↗