Dynamics of Baryons from String Theory and Vector Dominance

Deog Ki Hong; Mannque Rho; Ho-Ung Yee; Piljin Yi

doi:10.1088/1126-6708/2007/09/063

paper

Dynamics of Baryons from String Theory and Vector Dominance

arXiv:0705.2632 · doi:10.1088/1126-6708/2007/09/063

Abstract

We consider a holographic model of QCD from string theory, a la Sakai and Sugimoto, and study baryons. In this model, mesons are collectively realized as a five-dimensional $U(N_F)=U(1)\times SU(N_F) $Y an g - M i l l s f i e l d an d ba r y o n s a r ec l a ss i c a l l y i d e n t i f i e d a s$ SU(N_F) $so l i t o n s w i t ha u ni tP o n t r y a g inn u mb er an d$ N_c $e l ec t r i cc ha r g es . T h eso l i t o ni ss h o w n t o b e v er y s ma l l in t h e l a r g e^{'} t H oo f t co u pl in g l imi t, a l l o w in g u s t o in t r o d u ce an e f f ec t i v e f i e l d$ {\cal B} $. I t sco u pl in g t o t h e m eso n s a r e d i c t a t e d b y t h eso l i t o n s t r u c t u r e, an d co n s i s t so f a d i r ec t ma g n e t i cco u pl in g t o t h e$ SU(N_F) $f i e l d s t r e n g t ha s w e l l a s aminima l co u pl in g t o t h e$ U(N_F) $g a ug e f i e l d . U p o n t h e d im e n s i o na l r e d u c t i o n, t hi se f f ec t i v e a c t i o n r e p r o d u ces a l l in t er a c t i o n t er m s b e tw ee nn u c l eo n s an d anin f ini t e t o w er o f m eso n s inamann er co n s i s t e n tw i t h t h e l a r g e$ N_c$ expansion. We further find that all electromagnetic interactions, as inferred from the same effective action via a holographic prescription, are mediated by an infinite tower of vector mesons, rendering the baryon electromagnetic form factors completely vector-dominated as well. We estimate nucleon-meson couplings and also the anomalous magnetic moments, which compare well with nature.

65pages, 3 figures, vector mesons and axial-vector mesons are now canonically normalized (comparisons with data and conclusions unaffected)

Dynamics of Baryons from String Theory and Vector Dominance

Abstract

References in corpus (61)

Cited by in corpus (109)