9 research outputs found
Two Particle Azimuthal Correlations in 4.2A GeV C+Ta Collisions
Two particle azimuthal correlations are studied in 4.2A GeV C+Ta collisions
observed with the 2-m propane bubble chamber exposed at JINR Dubna
Synchrophasotron. The correlations are analyzed both for protons and negative
pions, and their dependence on the collision centrality, rapidity and rapidity
difference is investigated. It is found that protons show a weak back-to-back
correlations, while a side-by-side correlations are observed for negative
pions. Restricting both protons to the target or projectile fragmentation
region, the side-by-side correlations are observed for protons also. Using the
two particle correlation function, the flow analysis is performed and intensity
of directed flow is determined without event-by event estimation of the
reaction plane.Comment: 4 pages, 3 figure
Asymptotic dynamics of the alternate degrees of freedom for a two-mode system: an analytically solvable model
The composite systems can be non-uniquely decomposed into parts (subsystems).
Not all decompositions (structures) of a composite system are equally
physically relevant. In this paper we answer on theoretical ground why it may
be so. We consider a pair of mutually un-coupled modes in the phase space
representation that are subjected to the independent quantum amplitude damping
channels. By investigating asymptotic dynamics of the degrees of freedom, we
find that the environment is responsible for the structures non-equivalence.
Only one structure is distinguished by both locality of the environmental in
uence on its subsystems and a classical-like description.Comment: 11 pages, no figures/table
Geometric Phase for Analytically Solvable Driven Time-Dependent Two-Level Quantum Systems
Geometric phase for novel analytical solutions (Barnes and Das Sarma) of time-dependent two-level quantum systems is discussed, specifically for a general single-axis driving term, which is represented by a function J(t) in the Hamiltonian, and its corresponding evolution operator. It is demonstrated how general results for corresponding phases (total, dynamic and geometric) can be obtained. Using a specific case, it was found that over time in which the driving field is appreciably different from zero, the corresponding geometric phase changes (in the specific example by Δ β ≈ 0.8 radians) thus enabling detection. The results are relevant to qubit control and to quantum computing applications