It is possible to express a general Green's function in momentum-space as a sum of (individually non-covariant) time ordered graphs. These are obtained by carrying out the energy integrals of the loop momenta in a Feynman diagram. In this representation internal lines travel on-shell but energy is not conserved at each vertex, while in a Feynman graph energy is conserved at each vertex but...
We study the weak decay of the $\Lambda_b$ baryon into $J/\psi \phi \Lambda$. This reaction is particularly interesting as it allows for the study of exotic or new hadron resonances in all the three two-particle channels (i.e, $J/\psi \phi$, $J/\phi \Lambda$ and $\phi \Lambda$).
It is interesting to study the final state interaction of $J/\psi$ and $\phi$, since as we know from experimental...
The possibility of triggering the QCD phase transition using the Unruh effect is considered. We use Chiral Perturbation Theory at leading order and the large $N$ limit (with $N$ being the number of pions) as an effective description of low-energy QCD, and the Thermalization Theorem to compute the relevant partition function. In complete analogy with the inertial, finite-temperature case, we...
An appealing inflationary scenario that, for some models, resolves the problem of the flatness of the potential is called ‘warm inflation’. In this model, there is a sizeable production of radiation alongside the inflationary expansion. The inflaton-radiation coupling leads to a significant enhancement of the power spectrum. One needs to consider an imperfect fluid that gives rise to...
We consider an effective non-linear Electroweak Chiral Lagrangian containing three would-be Goldstone bosons: $\omega^a$ which transform non-linearly as a triplet under $SU(2)_L \times SU(2)_R $ and a Higgs singlet $h$ plus its couplings to fermions via Yukawa interactions. This low energy model is valid for the range $M_h,M_W,M_Z \ll s \ll 4 \pi v \simeq 3$ TeV.
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Since the...
