An upper bound on the coupling constant of scalar mesons

Abstract We study charged black hole solutions in 4-dimensional (4D) Einstein–Gauss–Bonnet–Maxwell theory to the linearized perturbation level. We first compute the shear viscosity to entropy density ratio. We then demonstrate how bulk causal structure analysis imposes an upper bound on the Gauss–Bonnet coupling constant in the AdS space. Causality constrains the value of Gauss–Bonnet coupling constant $$\alpha _{GB}$$αGB to be bounded by $$\alpha _{GB}\le 0$$αGB≤0 as $$D\rightarrow 4$$D→4.

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The nucleon–nucleon interaction. I. Scalar mesons

Canadian Journal of Physics ◽

10.1139/p76-037 ◽

1976 ◽

Vol 54 (3) ◽

pp. 322-332

Author(s):

A. Z. Capri ◽

D. Menon ◽

R. Teshima

Keyword(s):

Bound States ◽

Bound State ◽

Nucleon Nucleon ◽

Phase Shifts ◽

Variational Calculation ◽

Coupling Constant ◽

Nucleon Interaction ◽

Scalar Mesons ◽

T Matrix ◽

Nucleon Nucleon Interaction

The two-nucleon interaction, via the exchange of scalar mesons, is examined in a nonperturbative manner. 'Schrödinger' equations are derived, and nonlocal potentials arise naturally. Both scattering and bound states are examined. A half-off-shell T matrix is obtained, and corresponding phase shifts are evaluated. In the bound state, a variational calculation is employed to determine the coupling constant.

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The $$D_s^+ \rightarrow a_0(980) e^+ \nu _e$$ reaction and the $$a_0(980)-f_0(980)$$ mixing

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09820-3 ◽

2021 ◽

Vol 81 (11) ◽

Author(s):

Jia-Xin Lin ◽

Jia-Ting Li ◽

Sheng-Juan Jiang ◽

Wei-Hong Liang ◽

E. Oset

Keyword(s):

Upper Bound ◽

Production Mechanism ◽

Scalar Mesons ◽

Isospin Violation ◽

Neutral Kaons ◽

Scalar Resonances ◽

Different Sources

AbstractWe perform a study of the $$D_s^+ \rightarrow a_0(980)(f_0(980)) e^+ \nu _e$$ D s + → a 0 ( 980 ) ( f 0 ( 980 ) ) e + ν e reactions investigating the different sources of isospin violation which make the production of the $$a_0(980)$$ a 0 ( 980 ) possible. We find that loops involving kaons in the production mechanism provide a source of isospin violation since they do not cancel due to the different mass of charged and neutral kaons, but we also find that the main source comes from the breaking of isospin in the meson-meson transition T matrices, which contain information on the nature of the low lying scalar mesons. The reaction is thus very sensitive to the nature of the $$a_0(980)$$ a 0 ( 980 ) and $$f_0(980)$$ f 0 ( 980 ) resonances. Our results are consistent with the present upper bound for $$a_0(980)$$ a 0 ( 980 ) production and only a factor three smaller, indicating that future runs with more statistics should find actual numbers for this reaction from where we can learn more about the origin of the scalar resonances and their nature.

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Shear viscosity, instability and the upper bound of the Gauss-Bonnet coupling constant

Journal of High Energy Physics ◽

10.1088/1126-6708/2009/05/051 ◽

2009 ◽

Vol 2009 (05) ◽

pp. 051-051 ◽

Cited By ~ 74

Author(s):

Xian-Hui Ge ◽

Sang-Jin Sin

Keyword(s):

Shear Viscosity ◽

Upper Bound ◽

Coupling Constant

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2S and 3S State Masses and decay constants of heavy-flavour mesons in a non-relativistic QCD potential model with three-loop effects in V-scheme

The European Physical Journal C ◽

10.1140/epjc/s10052-020-08756-4 ◽

2020 ◽

Vol 80 (12) ◽

Author(s):

Rashidul Hoque ◽

B. J. Hazarika ◽

D. K. Choudhury

Keyword(s):

Perturbation Theory ◽

Strong Coupling ◽

Potential Model ◽

Dynamic Properties ◽

Strong Coupling Constant ◽

Coupling Constant ◽

Decay Constants ◽

Scalar Mesons ◽

Experimental Values ◽

Pseudo Scalar

AbstractWe make an analysis of three -loop effects of the strong coupling constant in the study of masses and decay constants of the heavy-flavour pseudo-scalar mesons (PSM) D, $$D_s$$ D s , B, $$B_s,$$ B s , $$B_c$$ B c , $$\eta _c$$ η c and $$\eta _b$$ η b in a non-relativistic QCD potential model using Dalgarno’s perturbation theory (DPT). The first order mesonic wavefunction is obtained using Dalgarno’s perturbation theory. The three-loop effects of strong coupling constant are included in the wave function in co-ordinate space and then used to examine the static and dynamic properties of the heavy-flavour mesons for 2S and 3S higher states. The results are compared with the other models available and are found to be compatible with available experimental values. In V-scheme, the three-loop effects on masses and decay constants of heavy-flavour mesons show a significant result.

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THE BOUND ON THE RENORMALIZED CHARGE IN QUANTUM ELECTRODYNAMICS AND IN THE WESS-ZUMINO MODEL

Modern Physics Letters A ◽

10.1142/s0217732391000701 ◽

1991 ◽

Vol 06 (08) ◽

pp. 693-699 ◽

Cited By ~ 1

Author(s):

N.V. KRASNIKOV

Keyword(s):

Upper Bound ◽

Quantum Electrodynamics ◽

Space Time ◽

Coupling Constant ◽

Renormalized Charge ◽

Zumino Model

An upper bound on the renormalized coupling constant α≤3πε+O(ε2) is found in quantum electrodynamics in n=4–2ε space-time. Analogous bound is obtained for a la Speer regularized Wess-Zumino model. The obtained bound means the triviality of QED and the Wess-Zumino model in the limit of the regularization removing.

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