One-time equation for the scattering of a particle on a bound state in quantum field theory

1974 ◽  
Vol 19 (3) ◽  
pp. 536-545 ◽  
Author(s):  
A. A. Arkhipov ◽  
V. I. Savrin
1974 ◽  
Vol 52 (20) ◽  
pp. 1988-1994 ◽  
Author(s):  
Roger Palmer ◽  
Yasushi Takahashi

We examined the problem of the appearance of negative norm states in multimass models. It is shown explicitly how the bound state with the same quantum numbers as the elementary meson, can acquire the positive norm. It is inferred from our argument that the multimass system of dynamical origin can be quantized without the negative norm, contrary to the multimass system of kinematical origin.


2020 ◽  
Vol 241 ◽  
pp. 02008
Author(s):  
Craig D. Roberts

One of the greatest challenges within the Standard Model is to discover the source of visible mass. Indeed, this is the focus of a “Millennium Problem”, posed by the Clay Mathematics Institute. The answer is hidden within quantum chromodynamics (QCD); and it is probable that revealing the origin of mass will also explain the nature of confinement. In connection with these issues, this perspective will describe insights that have recently been drawn using contemporary methods for solving the continuum bound-state problem in relativistic quantum field theory and how they have been informed and enabled by modern experiments on nucleon-resonance electroproduction.


2006 ◽  
Vol 21 (21) ◽  
pp. 1657-1673 ◽  
Author(s):  
ZHI-FENG LI ◽  
WOLFGANG LUCHA ◽  
FRANZ F. SCHÖBERL

Recently an instantaneous approximation to the Bethe–Salpeter formalism for the analysis of bound states in quantum field theory has been proposed which retains, in contrast to the Salpeter equation, as far as possible the exact propagators of the bound-state constituents, extracted nonperturbatively from Dyson–Schwinger equations or lattice gauge theory. The implications of this improvement for the solutions of this bound-state equation, i.e. the spectrum of the mass eigenvalues of its bound states and the corresponding wave functions, when considering the quark propagators arising in quantum chromodynamics are explored.


1992 ◽  
Vol 70 (6) ◽  
pp. 412-426 ◽  
Author(s):  
Leo Di Leo ◽  
Jurij W. Darewych

We derive relativistic particle–antiparticle wave equations for scalar particles, [Formula: see text] and [Formula: see text], interacting via a massive or massless scalar field, χ (the Wick–Cutkosky model). The variational method, within the Hamiltonian formalism of quantum field theory is used to derive equations with and without coupling of this quasi-bound [Formula: see text] system to the χχ decay channel. Bound-state energies in the massless case are compared with the ladder Bethe–Salpeter and light-cone results. In the case of coupling to the decay channel, the quasi-bound [Formula: see text] states are seen to arise as resonances in the χχ scattering cross section. Numerical results are presented for the massive and massless χ case.


2020 ◽  
Vol 8 (4) ◽  
Author(s):  
Ben Freivogel ◽  
Thomas Gasenzer ◽  
Arthur Hebecker ◽  
Sascha Leonhardt

We conjecture that, in a renormalizable effective quantum field theory where the heaviest stable particle has mass mm, there are no bound states with radius below 1/m1/m (Bound State Conjecture). We are motivated by the (scalar) Weak Gravity Conjecture, which can be read as a statement forbidding certain bound states. As we discuss, versions for uncharged particles and their generalizations have shortcomings. This leads us to the suggestion that one should only constrain rather than exclude bound objects. In the gravitational case, the resulting conjecture takes the sharp form of forbidding the adiabatic construction of black holes smaller than 1/m1/m. But this minimal bound-state radius remains non-trivial as M_\mathrm{P}\to \inftyMP→∞, leading us to suspect a feature of QFT rather than a quantum gravity constraint. We find support in a number of examples which we analyze at a parametric level.


1987 ◽  
Vol 36 (8) ◽  
pp. 2506-2511 ◽  
Author(s):  
L. S. Celenza ◽  
Chueng-Ryong Ji ◽  
C. M. Shakin

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