A Scaling Phenomenon in Shannon Information Uncertainty Difference of fragments in Heavy-ion Collisions

Finite-size scaling phenomenon of nuclear liquid--gas phase transition probes

Based on the isospin-dependent quantum molecular dynamics model, finite-size scaling effects on nuclear liquid--gas phase transition probes are investigated by studying the de-excitation processes of six thermal sources of different sizes with the same initial density and similar $N/Z$. Using several probes including the total multiplicity derivative ($dM_{tot}/dT$), second moment parameter ($M_2$), intermediate mass fragment (IMF) multiplicity ($N_{IMF}$), Fisher's power-law exponent ($τ$), and Ma's nuclear Zipf's law exponent ($ξ$), the relationship between the phase transition temperature a…

Projectile fragmentation reactions and production of nuclei near the neutron drip-line

The reaction mechanism of projectile fragmentation at intermediate energies has been investigated observing the target dependence of the production cross sections of very neutron-rich nuclei. Measurement of longitudinal momentum distributions of projectile-like fragments within a wide range of fragment mass and its charge was performed using a hundred-MeV/n $^{40}$Ar beam incident on Be and Ta targets. By measurement of fragment momentum distribution, a parabolic mass dependence of momentum peak shift was observed in the results of both targets, and a phenomenon of light-fragment acceleration …

The Influence of in-medium NN cross-sections, symmetry potential and impact parameter on the isospin observables

We explore the influence of in-medium nucleon-nucleon cross section, symmetry potential and impact parameter on isospin sensitive observables in intermediate-energy heavy-ion collisions with the ImQMD05 code, a modified version of Quantum Molecular Dynamics model. At incident velocities above the Fermi velocity, we find that the density dependence of symmetry potential plays a more important role on the double neutron to proton ratio $DR(n/p)$ and the isospin transport ratio $R_i$ than the in-medium nucleon-nucleon cross sections, provided that the latter are constrained to a fixed total NN co…

Extended Longitudinal Scaling: direct evidence of saturation

Multiparticle production of charged particles at high energies exhibit the phenomenon of Limiting Fragmentation. Furthermore, the region in rapidity over which the production of particles appears to be independent of energy, increases with energy. It is argued that this phenomenon, known as Extended Longitudinal Scaling, is a direct manifestation of some kind of saturation, akin to that in the Color Glass Condensate picture of particle production.

Solitonic excitations in collisions of superfluid nuclei: a qualitatively new phenomenon distinct from the Josephson effect

Recently, we have reported a novel role of pairing in low-energy heavy ion reactions at energies above the Coulomb barrier, which may have a detectable impact on reaction outcomes, such as the kinetic energy of fragments and the fusion cross section [arXiv:1611.10261, arXiv:1702.00069]. The phenomenon mimics the one studied experimentally with ultracold atomic gases, where two clouds of fermionic superfluids with different phases of the pairing fields are forced to merge, inducing various excitation modes of the pairing field. Although it originates from the phase difference of the pairing fie…

研究胶子饱和引起的双粒子关联展宽现象

Investigating the broadening phenomenon in two-particle correlations induced by gluon saturation

本文分析双粒子背靠背角关联展宽，指出初态部分子簇射与碎裂横向运动等非饱和效应会掩盖胶子饱和信号。

Measurements of jets and jet properties in $\sqrt{s_{NN}} = 2.76$ TeV lead-lead collisions with the ATLAS detector at the LHC

Jet quenching in the hot and dense medium created in ultra-relativistic heavy ion collisions is a well-established experimental phenomenon at RHIC. It has long been anticipated that the LHC heavy ion program would substantially advance the study of jet quenching by providing access to highly energetic jets and by measuring fully-reconstructed jets. Immediately following turn-on of the LHC with lead beams, in November 2010, that expectation was fulfilled through the observation of large di-jet asymmetries that may indicate substantial jet quenching. We will present recent results from ATLAS aim…