Static strings in Randall-Sundrum scenarios and the quark-antiquark potential

This paper is a continuation of ArXiv:0707.1324 where improved holographic theories for QCD were set up and explored. Here, the IR confining geometries are classified and analyzed. They all end in a "good" (repulsive) singularity in the IR. The glueball spectra are gapped and discrete, and they favorably compare to the lattice data. Quite generally, confinement and discrete spectra imply each other. Asymptotically linear glueball masses can also be achieved. Asymptotic mass ratios of various glueballs with different spin also turn out to be universal. Meson dynamics is implemented via space filling D 4 −D 4 brane pairs. The associated tachyon dynamics is analyzed and chiral symmetry breaking is shown. The dynamics of the RR axion is analyzed, and the non-perturbative running of the QCD θ-angle is obtained. It is shown to always vanish in the IR. Appendices 66 A. Characterization of confining backgrounds 66 A.1 Unbounded conformal coordinate 67 A.1.1 Logarithmic divergence 67 A.1.2 Power-law divergence 68 A.2 Finite range of the conformal coordinate 69 A.2.1 Finite A(r 0 ) 69 A.2.2 Power-law divergence 70 A.2.3 Logarithmic divergence 71 B. Magnetic charge screening: the finite range 72 B.1 A(r 0 ) finite 72 B.2 A(r 0 ) → −∞ 72 C. Fundamental string world-sheet embeddings in the presence of a non-trivial dilaton 73 D. Singularities of the tachyon 75 E. The superpotential versus the potential 76 F. Standard AdS/QCD Glueball spectrum 78 G. A simple analytic solution with AdS and confining asymptotics 79 References 80 -2 -6 The singularity is at a finite value u IR of the u coordinate. See appendix A. 7Since we are assuming that the singularity is at r → ∞, and Φ is monotonically increasing from Φ = −∞ at r = 0, A S cannot diverge to −∞ at some finite r. Therefore, if there is a minimum for A S , the string tension is certainly finite.

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“…This was computed for the cut-off AdS 5 background in e.g. [16], where the expected area law was found.…”

Section: Absence Of Screening In Hard-wall Modelsmentioning

confidence: 99%

Exploring improved holographic theories for QCD: part II

Gürsoy¹,

Kiritsis²,

Nitti³

2008

J. High Energy Phys.

466

821

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“…This simple prescription, which has been described as a "bottom-up" approach, has been successful in obtaining general properties of scattering amplitudes of hadronic bound states at strong coupling [34,36,37,38,39,40], the low-lying hadron spectra [35,41,42,43,44,45,46,47,48,49], hadron couplings and chiral symmetry breaking [41,50,51,52,53], quark potentials in confining backgrounds [54,55], a description of weak hadron decays [56] and euclidean correlation functions [57]. Geometry back-reaction in AdS may also be relevant to the infrared physics [58] and wall dynamics [59].…”

Section: Introductionmentioning

confidence: 99%

AdS/CFT and Light-Front QCD

Brodsky

Téramond

2009

Search for the “Totally Unexpected” in the LHC Era

103

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The AdS/CFT correspondence between string theory in AdS space and conformal field theories in physical space-time leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. The AdS/CFT correspondence also provides insights into the inherently nonperturbative aspects of QCD such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of AdS space z and a specific impact variable ζ which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection leads to AdS/CFT predictions for the analytic form of the frameindependent light-front wavefunctions (LFWFs) of mesons and baryons, the fundamental entities which encode hadron properties. The LFWFs in turn predict decay constants and spin correlations, as well as dynamical quantities such as form factors, structure functions, generalized parton distributions, and exclusive scattering amplitudes. Relativistic light-front equations in ordinary space-time are found which reproduce the results obtained using the fifth-dimensional theory and have remarkable algebraic structures and integrability properties. As specific examples we describe the behavior of the pion form factor in the space and time-like regions and determine the Dirac nucleon form factors in the space-like region. An extension to nonzero quark mass is used to determine hadronic distribution amplitudes of all mesons, heavy and light. We compare our results with the moments of the distribution amplitudes which have recently been computed from lattice gauge theory.

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“…This picture shows a minimum value of 0 which we call * . Note that it is also possible to find * from (11) and (13). Using these equations, we get an expression whose root is precisely * :…”

Section: Confiningmentioning

confidence: 99%

“…For instance, the hard-wall model exhibits a confining behaviour [13,14] reproducing the Cornell potential. At finite temperature, this calculation gives a second-order phase transition describing qualitatively a confinement/deconfinement phase transition [15].…”

Section: Introductionmentioning

confidence: 99%

A Study of Confinement for QQ- Potentials on D3, M2, and M5 Branes

Quijada

Boschi-Filho

2017

Advances in High Energy Physics

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this article was funded by SCOAP 3 .We study analytically and numerically the interaction potentials between a pair of quark and antiquark on D3, M2, and M5 branes. These potentials are obtained using Maldacena's method involving Wilson loops and present confining and nonconfining behaviours in different situations that we explore in this work. In particular, at the near horizon geometry, the potentials are nonconfining in agreement with conformal field theory expectations. On the other side, far from horizon, the dual field theories are no longer conformal and the potentials present confinement. This is in agreement with the behaviour of strings in flat space where the string mimics the expected flux tube of QCD. A study of the transition between the confining/nonconfining regimes in the three different scenarios (D3, M2, and M5) is also performed.

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Static strings in Randall-Sundrum scenarios and the quark-antiquark potential

Cited by 55 publications

References 41 publications

Exploring improved holographic theories for QCD: part II

Exploring improved holographic theories for QCD: part II

AdS/CFT and Light-Front QCD

A Study of Confinement for QQ- Potentials on D3, M2, and M5 Branes

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