L. Albino, G. Paredes-Torres, K. Raya, A. Bashir, J. Segovia
{"title":"γ(*)+N(940)12+→N(1520)32− helicity amplitudes and transition form factors","authors":"L. Albino, G. Paredes-Torres, K. Raya, A. Bashir, J. Segovia","doi":"10.1103/qpr2-nwtw","DOIUrl":null,"url":null,"abstract":"We recently reported new results on the γ</a:mi></a:mrow>(</a:mo>*</a:mo>)</a:mo></a:mrow></a:msup>+</a:mo>N</a:mi>(</a:mo>940</a:mn>)</a:mo>1</a:mn></a:mrow>2</a:mn></a:mrow></a:mfrac></a:mrow>+</a:mo></a:mrow></a:msup>→</a:mo>Δ</a:mi>(</a:mo>1700</a:mn>)</a:mo>3</a:mn></a:mrow>2</a:mn></a:mrow></a:mfrac></a:mrow>−</a:mo></a:mrow></a:msup></a:mrow></a:math> transition form factors using a symmetry-preserving treatment of a vector <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><k:mo stretchy=\"false\">⊗</k:mo></k:math>vector contact interaction (SCI) within a coupled formalism based on the Dyson-Schwinger, Bethe-Salpeter, and Faddeev equations. In this work, we extend our investigation to the <n:math xmlns:n=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><n:mrow><n:msup><n:mrow><n:mi>γ</n:mi></n:mrow><n:mrow><n:mo stretchy=\"false\">(</n:mo><n:mo>*</n:mo><n:mo stretchy=\"false\">)</n:mo></n:mrow></n:msup><n:mo>+</n:mo><n:mi>N</n:mi><n:mo stretchy=\"false\">(</n:mo><n:mn>940</n:mn><n:mo stretchy=\"false\">)</n:mo><n:msup><n:mrow><n:mfrac><n:mrow><n:mn>1</n:mn></n:mrow><n:mrow><n:mn>2</n:mn></n:mrow></n:mfrac></n:mrow><n:mrow><n:mo>+</n:mo></n:mrow></n:msup><n:mo stretchy=\"false\">→</n:mo><n:mi>N</n:mi><n:mo stretchy=\"false\">(</n:mo><n:mn>1520</n:mn><n:mo stretchy=\"false\">)</n:mo><n:msup><n:mrow><n:mfrac><n:mrow><n:mn>3</n:mn></n:mrow><n:mrow><n:mn>2</n:mn></n:mrow></n:mfrac></n:mrow><n:mrow><n:mo>−</n:mo></n:mrow></n:msup></n:mrow></n:math> transition. Our computed transition form factors show reasonable agreement with experimental data at large photon virtualities. However, deviations emerge at low <w:math xmlns:w=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><w:msup><w:mi>Q</w:mi><w:mn>2</w:mn></w:msup></w:math>, where experimental results exhibit a sharper variation than theoretical predictions. This discrepancy is expected, as these continuum QCD analyses account only for the quark-core of baryons, while low photon virtualities are dominated by meson cloud effects. We anticipate that these analytical predictions, based on the simplified SCI framework, will serve as a valuable benchmark for more refined studies and QCD-based truncations that incorporate quark angular momentum and the contributions of scalar and vector diquarks.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"13 1","pages":""},"PeriodicalIF":5.3000,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review D","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/qpr2-nwtw","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
We recently reported new results on the γ(*)+N(940)12+→Δ(1700)32− transition form factors using a symmetry-preserving treatment of a vector ⊗vector contact interaction (SCI) within a coupled formalism based on the Dyson-Schwinger, Bethe-Salpeter, and Faddeev equations. In this work, we extend our investigation to the γ(*)+N(940)12+→N(1520)32− transition. Our computed transition form factors show reasonable agreement with experimental data at large photon virtualities. However, deviations emerge at low Q2, where experimental results exhibit a sharper variation than theoretical predictions. This discrepancy is expected, as these continuum QCD analyses account only for the quark-core of baryons, while low photon virtualities are dominated by meson cloud effects. We anticipate that these analytical predictions, based on the simplified SCI framework, will serve as a valuable benchmark for more refined studies and QCD-based truncations that incorporate quark angular momentum and the contributions of scalar and vector diquarks.
期刊介绍:
Physical Review D (PRD) is a leading journal in elementary particle physics, field theory, gravitation, and cosmology and is one of the top-cited journals in high-energy physics.
PRD covers experimental and theoretical results in all aspects of particle physics, field theory, gravitation and cosmology, including:
Particle physics experiments,
Electroweak interactions,
Strong interactions,
Lattice field theories, lattice QCD,
Beyond the standard model physics,
Phenomenological aspects of field theory, general methods,
Gravity, cosmology, cosmic rays,
Astrophysics and astroparticle physics,
General relativity,
Formal aspects of field theory, field theory in curved space,
String theory, quantum gravity, gauge/gravity duality.