scholarly journals Four-pomeron vertex

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
M. A. Braun
Keyword(s):  
Perturbative Qcd ◽  
Variational Approach ◽  
Equations Of Motion ◽  
Iterative Solution ◽  
Infrared Region ◽  
The Other ◽  
Coupling Constant ◽  
Large Coupling ◽  
Large Coupling Constant

AbstractThe four-pomeron vertex is studied in the perturbative QCD. Its dominating terms of the leading (zeroth and first) orders in the coupling constant and subdominant in the number of colors are constructed. The vertex consists of two terms, one with a derivative in rapidity $$\partial _y$$ ∂ y and the other with the BFKL interaction between pomerons. The corresponding part of the action and equations of motion are found. The iterative solution of the latter is possible only for rapidities smaller than 2 and quite large coupling constant $$\alpha _s$$ α s , of the order or greater than unity, when the quadruple pomeron interaction is relatively small. Also iteration of the part with $$\partial _y$$ ∂ y is unstable in the infrared region and compels to introduce an infrared cut. The variational approach with simple trying functions allows to find the minimum of the action at $$\alpha _s$$ α s of the order 0.2 and rapidities up to 25. Numerical estimates for O–O collisions show that actually the influence of the quadruple pomeron interaction turns out to be rather small.

scholarly journals Preparation and Spectroscopic Characterization of trans-Fe(CO)3L1L2 (L1, L2 = Phosphine or Phosphite)

1989 ◽  
Vol 44 (6) ◽  
pp. 641-646 ◽  
Author(s):  
Hidenari Inoue ◽  
Takeshi Kuroiwa ◽  
Tsuneo Shirai ◽  
Ekkehard Fluck
Keyword(s):  
Spectroscopic Characterization ◽  
Coupling Constant ◽  
Positive Slope ◽  
Phosphorus Ligands ◽  
Large Coupling ◽  
Iron Carbonyls ◽  
Trigonal Bipyramidal ◽  
Large Coupling Constant ◽  
Back Donation

The 57Fe Mößbauer spectra of mixed ligand complexes of the type trans-Fe(CO)3L1L2 (L1 = triphenylphosphine or triphenylphosphite and L2 = phosphine or phosphite) show a quadrupolesplitting doublet typical of the disubstituted iron carbonyls in trigonal bipyramidal symmetry. The inverse linear dependence of the isomer shifts on the CO stretching frequencies is interpreted on the basis of the strengthening triple-bond nature of the carbonyl ligands with increasing iron-to-phosphorus π-back donation. A linear correlation, with a positive slope, between the isomer shifts and the quadrupole splittings has revealed that the phosphorus-to-iron σ-donation is offset by the iron-to-phosphorus π-back donation. A correlation between the coordination shifts and the isomer shifts demonstrates that the iron-to-phosphorus π-back donation plays an important role in the Fe-P bond. The relatively large coupling constant of 2J(P,P) reflects a strong interaction between trans-phosphorus ligands through the P-Fe-P bond

PHASE STRUCTURE OF THREE- AND FOUR-DIMENSIONAL ϕ4 FIELD THEORY

1992 ◽  
Vol 07 (19) ◽  
pp. 4539-4558 ◽  
Author(s):  
G.V. EFIMOV ◽  
S.N. NEDELKO
Keyword(s):  
Field Theory ◽  
Renormalization Group ◽  
Strong Coupling ◽  
Phase Structure ◽  
Space Time ◽  
Strong Coupling Regime ◽  
Canonical Transformations ◽  
Coupling Constant ◽  
Large Coupling ◽  
Large Coupling Constant

The strong coupling regime of gϕ4 theory in space-time Rd for d=3, 4 is investigated by the methods of canonical transformations and the renormalization group. It is shown that the model describes a system symmetric under transformation ϕ→−ϕ both at small and large coupling constant g. Comparison with the case d=2 shows a crucial influence of the renormalization structure of the theory on its phase structure.

scholarly journals Multiphoton annihilation of monopolium

2017 ◽  
Vol 32 (35) ◽  
pp. 1750202 ◽  
Author(s):  
H. Fanchiotti ◽  
C. A. García Canal ◽  
V. Vento
Keyword(s):  
Coupling Constant ◽  
Final State ◽  
Photon Interaction ◽  
Large Coupling ◽  
Two Photon ◽  
Large Coupling Constant

We show that due to the large coupling constant of the monopole–photon interaction the annihilation of monopole–antimonopole and monopolium into many photons must be considered experimentally. For monopole–antimonopole annihilation and lightly bound monopolium, even in the less favorable scenario, multiphoton events (four and more photons in the final state) are dominant, while for strongly bound monopolium, although two photon events are important, four- and six-photon events are also sizable.

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