The role of five-quark components in gamma decay of the $\Delta (1232)$

Abstract

An admixture of 10-20 % of qqqq\bar q components in the Delta(1232) resonance is shown to reduce the well known underprediction for the decay width for Delta(1232)->N gamma decay by about half and that of the corresponding helicity amplitudes from a factor ~ 1.7 to ~ 1.5. The main effect is due to the quark-antiquark annihilation transitions qqqq\bar q -> qqq gamma, the consideration of which brings the ratio A_{3/2}/A_{1/2} and consequently the E2/M1 ratio R_{EM} into agreement with the empirical value. Transitions between qqqq\bar q components in the resonance and the nucleon qqqq\bar q->qqqq\bar q gamma are shown to enhance the calculated width by only a few percent, as long as the probability of the qqqq\bar q component of the Delta(1232) and the proton is at most ~ 20 %. The transitions qqqq\bar q->qqqq\bar q gamma between the qqqq\bar q components in the Delta(1232) and the proton do not lead to a nonzero value for R_{EM}.

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Cited by in corpus (18)

• Study of $qqqc\bar{c}$ five quark system with three kinds of quark-quark hyperfine interaction
• D-state effects in the electromagnetic N-Delta transition
• Valence quark contribution for the gamma N -> Delta quadrupole transition extracted from lattice QCD
• The role of the $qqqq\bar{q}$ components in the electromagnetic transition ${\gamma }^{\ast }N\to N^{\ast }(1535)$
• Five-quark components in baryons
• The role of $qqqq\bar{q}$ components in the nucleon and the N(1440) resonance
• The role of $q\bar{q}$ components in the N(1440) resonance
• Electromagnetic Transition Form Factors of Baryon Resonances
• The $qqqq\bar{q}$ components and hidden flavor contributions to the baryon magnetic moments
• The strangeness form factors of the proton
• Strong decay of low-lying $S_{11}$ and $D_{13}$ nucleon resonances to pseudoscalar mesons and octet baryons
• Role of five-quark components in radiative and strong decays of the Lambda(1405) resonance
• Spectrum of low-lying $s^{3}Q\bar{Q}$ configurations with negative parity
• Sea flavor content of octet baryons and intrinsic five-quark Fock states
• The small axial charge of the N(1535) resonance
• The $qqqq\bar{q}$ components and the magnetic moments of the charmed and the bottomed baryons
• The contributions of $qqqq\bar{q}$ components to the axial charges of proton and its resonances
• The quark orbital angular momentum of ground state octet baryons