Completing the Picture of the Roper Resonance

Autor(es)

Segovia, Jorge ^{[1, 2]} ; El-Bennich, Bruno ^{[3, 4]} ; Rojas, Eduardo ^{[5, 4]} ; Cloet, Ian C. ^[6] ; Roberts, Craig D. ^[6] ; Xu, Shu-Sheng ^[7] ; Zong, Hong-Shi ^[7]

Afiliação do(s) autor(es)

^[1] Univ Salamanca, Grp Fis Nucl, E-37008 Salamanca - Spain

^[2] Univ Salamanca, IUFFyM, E-37008 Salamanca - Spain

^[3] Univ Estadual Paulista, Inst Fis Teor, BR-01140070 Sao Paulo, SP - Brazil

^[4] Univ Cruzeiro Sul, Lab Fis Teor & Computac, BR-01506000 Sao Paulo, SP - Brazil

^[5] Univ Antioquia, Inst Fis, Medellin - Colombia

^[6] Argonne Natl Lab, Div Phys, Argonne, IL 60439 - USA

^[7] Nanjing Univ, Dept Phys, Nanjing 210093, Jiangsu - Peoples R China

• Tipo de documento: Artigo Científico
• Fonte: Physical Review Letters; v. 115, n. 17 OCT 21 2015.
• Citações Web of Science: 54

Resumo

We employ a continuum approach to the three valence-quark bound-state problem in relativistic quantum field theory to predict a range of properties of the proton's radial excitation and thereby unify them with those of numerous other hadrons. Our analysis indicates that the nucleon's first radial excitation is the Roper resonance. It consists of a core of three dressed quarks, which expresses its valence-quark content and whose charge radius is 80% larger than the proton analogue. That core is complemented by a meson cloud, which reduces the observed Roper mass by roughly 20%. The meson cloud materially affects long-wavelength characteristics of the Roper electroproduction amplitudes but the quark core is revealed to probes with Q(2) greater than or similar to 3m(N)(2). (AU)

• Processo FAPESP: 13/16088-4 - Física hadrônica na era do "12 GeV upgrade" no Jefferson Lab e dos novos aceleradores para a física de sabores
• Beneficiário: Bruno Omar El Bennich
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/03275-8 - Efeitos de correções fermiônicas sem apagamento em mésons pesados
• Beneficiário: Eduardo Rojas Pena
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado