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T. Rogers

Publications and source records attributed to T. Rogers.

4 recordsLinked to original sources
arXiv2024

Avenues for a number density interpretation of dihadron fragmentation functions

In this comment, we reassess the underlying physics of the number sum rule for dihadron fragmentation functions. We will argue that, currently, there are no settled constraints on what constitutes a valid number density interpretation for multihadron fragmentation functions. Imposing overly restrictive criteria might lead to misinterpretating the data. Most importantly, and on the basis of phenomenological analyses, the slightly varying definitions used in previous work are not excluded from possessing legitimate number density interpretations (up to the usual issues with ultraviolet divergences and renormalization), so long as they are paired with appropriate factorization theorems. We advocate for further theoretical analyses to be challenged with experimental data, available at JLab or at the future EIC.

hep-ph↗
arXiv2022

The replicator coalescent

We consider a stochastic model, called the replicator coalescent, describing a system of blocks of $k$ different types which undergo pairwise mergers at rates depending on the block types: with rate $C_{i,j}$ blocks of type $i$ and $j$ merge, resulting in a single block of type $i$. The replicator coalescent can be seen as generalisation of Kingman's coalescent death chain in a multi-type setting, although without an underpinning exchangeable partition structure. The name is derived from a remarkable connection we uncover between the instantaneous dynamics of this multi-type coalescent when issued from an arbitrarily large number of blocks, and the so-called replicator equations from evolutionary game theory. By dilating time arbitrarily close to zero, we see that initially, on coming down from infinity, the replicator coalescent behaves like the solution to a certain replicator equation. Thereafter, stochastic effects are felt and the process evolves more in the spirit of a multi-type death chain.

math.PR↗
arXiv2004

Determining the Proximity of Γ^{\ast} N Scattering to the Black Body Limit Using DIS and J/ ψProduction

We use information about DIS and $J/ ψ$ production on hydrogen to model the $t$-dependence of the $γ^{\ast} N$ scattering amplitude. We investigate the profile function for elastic scattering of hadronic components of the virtual photon off both a nucleon and heavy nuclear target, and we estimate the value of the impact parameter where the black body limit is reached. We also estimate the fraction of the cross section that is due to hadronic configurations in the virtual photon wave function that approach the unitarity limit. We extract, from these considerations, approximate lower limits on the values of $x$ where the leading twist approximation in DIS is violated. We observe that the black body limit may be approached within HERA kinematics with $Q^{2}$ equal to a few GeV$^2$ and $x \sim 10^{-4}$. Comparisons are made with earlier predictions by Munier {\it et al.}, and the longitudinal structure function is compared with preliminary HERA data. The principle advantage of our method is that we do not rely solely on the $t$-dependence of $ρ$-meson production data. This allows us to extend our analysis down to very small impact parameters and dipole sizes. Finally, we perform a similar calculation with a $^{208}$Pb target, and we demonstrate that the black body limit is already approached at $Q^{2} \sim 20$ GeV$^{2}$ and $x \sim 10^{-4}$.

hep-ph↗