arXiv subjects

Farah Afzal

Publications and source records attributed to Farah Afzal.

5 recordsLinked to original sources

arXiv2026

Search for $\boldsymbol{π_1(1600)}$ in a three-pion system at GlueX

The GlueX experiment in Hall D at Jefferson Lab enables studies of the light meson spectrum in $γp$ interactions with a linearly polarized photon beam. GlueX aims in particular to search for hybrid mesons that have exotic quantum numbers and therefore cannot be classified as conventional hadrons. We present the search for the $π_1(1600)$ meson by means of a partial-wave analysis of the $π^{+}π^{-}π^{-}$ system produced off the $Δ^{++}$-baryon. Data with the selected three-pion final state are fitted in bins of $m_{3π}$ as coherent sums of partial-wave amplitudes defined in the reflectivity basis. The properties of $a_{2}^{-}(1320)$ production are investigated through the extracted signal in the $ρ\,π^{-}$ $D$-waves. In this analysis, the overall $m_{3π}$ lineshape will be extracted for each of the model contributions. The main interest lies in establishing the existence of a resonant $1^{-+}$ contribution in the $ρ\,π^{-}$ $P$-wave configuration.

hep-ex↗

arXiv2024

Proposal for PAC 52: Measurement of $α_-$ for $Λ\rightarrow pπ^-$

We propose to measure the weak decay constant $α_-$ for the decay $Λ\rightarrow pπ^-$ using a both circularly and linearly polarized photon beam with the GlueX spectrometer in Hall D. The measurement will take advantage of the fact that a measurement with both linear and circular photon beam polarization results in an over-constrained set of amplitudes which can be fitted to data and used to extract $α_-$ which will be left as a free parameter in the fit. We expect to determine $α_-$ with statistical uncertainties comparable to existing measurements and independent systematic uncertainties. This measurement can be performed alongside GlueX-II running and requires no new hardware or new beam time. The measurement requires that a sufficient fraction of the electron beam polarization be longitudinal in the Hall D tagger.

nucl-ex↗

arXiv2024

Truncated Partial-Wave Analysis for $η$-photoproduction observables via Bayesian Statistics

A truncated partial-wave analysis is performed for $η$-photoproduction using the polarization observables $σ_0, Σ, T, E, F$ and $G$. Different truncation orders are analyzed for six energy bins within the range of $E^{lab}_γ \in [750, 1250]$ MeV. Bayesian statistics is combined with truncated partial-wave analysis for the first time to investigate the structure of emerging ambiguities and their relevance in comparison to each other. Marginal distributions for the electromagnetic multipole parameters are presented together with predictions for polarization observables which have not yet been measured, in order to determine promising future measurements able to remove remaining mathematical ambiguities.

nucl-th↗

arXiv2022

Light Baryon Spectroscopy

This review treats the advances in Light Baryon Spectroscopy of the last two decades, which were mainly obtained by measuring meson-production reactions at photon facilities all over the world. We provide a consistent compendium of experimental results, as well as a review of the theoretical methods of amplitude analysis used to analyze the data. The most significant datasets are presented in detail and are listed in combination with a full set of the relevant references. In addition, a brief summary of spin-formalisms, which are ubiquitous in Light Baryon Spectroscopy, as well as a review on complete experiments, are provided. The synthesis of the reviewed knowledge is presented in a full interpretation of the new results on the Light Baryon Spectrum.

nucl-ex↗

arXiv2020

Minimal complete sets for two pseudoscalar meson photoproduction

For photoproduction reactions with final states consisting of two pseudoscalar mesons and a spin-1/2 baryon, 8 complex amplitudes need to be determined uniquely. A modified version of Moravcsik's theorem is employed for these reactions, resulting in slightly over-complete sets of polarization observables that are able to determine the amplitudes uniquely. Further steps were taken to reduce the found sets to minimal complete sets. As a final result, multiple minimal complete sets without any remaining ambiguities are presented for the first time. These sets consist of $2N=16$ observables, containing only one triple polarization observable.

nucl-th↗