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Time-crystal ground state and production of gravitational waves from QCD phase transition
Andrea Addazi, Antonino Marcianò, Roman Pasechnik
Published: , doi: 10.1088/1674-1137/43/6/065101
Abstract:
We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.
Structure, formation, and decay of ${{\bar{K}NN}}$ system by Faddeev-AGS calculations
S. Marri, S. Z. Kalantari, J. Esmaili
Published: , doi: 10.1088/1674-1137/43/6/064101
Abstract:
The Faddeev AGS equations for the coupled-channels $\bar{K}NN-\pi\Sigma{N}$ system with quantum numbers I = 1/2 and S = 0 are solved. Using separable potentials for the $\bar{K}N-\pi\Sigma$ interaction, we calculate the transition probability for the $(Y_{K})_{I=0}+N\rightarrow\pi\Sigma{N}$ reaction. The possibility to observe the trace of the $K^{-}pp$ quasi-bound state in $\pi\Sigma{N}$ mass spectra was studied. Various types of chiral-based and phenomenological potentials are used to describe the $\bar{K}N-\pi\Sigma$ interaction. Finally, we show that we can observe the signature of the $K^{-}pp$ quasi-bound state in the mass spectra, as well as the trace of branch points in the observables.
Triple α -particle resonances in the decay of hot nuclear systems
S. Zhang, J. C. Wang, A. Bonasera, M. R. Huang, H. Zheng, G. Q. Zhang, Z. Kohley, Y. G. Ma, S. J. Yennello
Published: , doi: 10.1088/1674-1137/43/6/064102
Abstract:
The Efimov (Thomas) trimers in excited 12C nuclei, for which no observation exists yet, are discussed by means of analyzing the experimental data of 70(64)Zn(64Ni) + 70(64)Zn(64Ni) reactions at the beam energy of E/A = 35 MeV/nucleon. In heavy ion collisions, $ \alpha $-particles interact with each other and can form complex systems such as 8Be and 12C. For the 3 $ \alpha $-particle systems, multi-resonance processes give rise to excited levels of 12C. The interaction between any two of the 3 $ \alpha $-particles provides events with one, two or three 8Be. Their interfering levels are clearly seen in the minimum relative energy distributions. Events with the three $ \alpha $-particle relative energies consistent with the ground state of 8Be are observed with the decrease of the instrumental error for the reconstructed 7.458 MeV excitation level in 12C, which was suggested as the Efimov (Thomas) state.