Search results for "phase space"
showing 10 items of 176 documents
Multipole compensation scheme for LHC low-beta insertions
1997
The LHC dynamic aperture in Physics conditions is determined by the field errors in the low-b quadrupoles and these errors set a lower limit to the value of b*. The associated aberrations have been computed with the transfer matrix method which gives particularly simple and efficient formulae for the case of low-b insertions. These formulae have been applied to the LHC case to design a multipole compensation system. The efficiency of the method has been assessed by trajectory tracking.
Measurement of double-differential muon neutrino charged-current interactions onC8H8without pions in the final state using the T2K off-axis beam
2016
We report the measurement of muon neutrino charged-current interactions on carbon without pions in the final state at the T2K beam energy using 5.734×1020 protons on target. For the first time the measurement is reported as a flux-integrated, double-differential cross section in muon kinematic variables (cosθμ, pμ), without correcting for events where a pion is produced and then absorbed by final state interactions. Two analyses are performed with different selections, background evaluations and cross-section extraction methods to demonstrate the robustness of the results against biases due to model-dependent assumptions. The measurements compare favorably with recent models which include n…
Probing the Quantum Interference between Singly and Doubly Resonant Top-Quark Production in pp Collisions at s=13 TeV with the ATLAS Detector
2018
This Letter presents a normalized differential cross-section measurement in a fiducial phase-space region where interference effects between top-quark pair production and associated production of a single top quark with a W boson and a b-quark are significant. Events with exactly two leptons (ee, μμ, or eμ) and two b-tagged jets that satisfy a multiparticle invariant mass requirement are selected from 36.1 fb^{-1} of proton-proton collision data taken at sqrt[s]=13 TeV with the ATLAS detector at the LHC in 2015 and 2016. The results are compared with predictions from simulations using various strategies for the interference. The standard prescriptions for interference modeling are signifi…
Spectra and correlations of Λ andΛ¯produced in 340-GeV/cΣ−+Cand 260-GeV/cn+Cinteractions
2002
We have measured the production of strange baryons and antibaryons in 340-GeV/c Sigma /sup -/+C and 260-GeV/c n+C interactions. The single x/sub F/ distributions show the expected leading particle effect, and the single p/sub t//sup 2/ distributions show a distinct nonthermal behavior. The x/sub F/ distributions of Lambda - Lambda pairs indicate two different phase space distributions for the two coincident baryons. On the other hand two Lambda 's show identical distributions. Momentum conservation during the formation process may represent a significant source for the observed behavior.
The KK¯π decay of the f1(1285) and its nature as a K*K¯ − cc molecule
2016
We investigate the decay of f1(1285)→πKK¯ with the assumption that the f1(1285) is dynamically generated from the K*K¯+cc interaction. In addition to the tree level diagrams that proceed via f1(1285)→K*K+cc→πKK¯, we take into account also the final state interactions of KK¯→KK¯ and πK → πK. The partial decay width and mass distributions of f1(1285)→πKK¯ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted mass distributions are significantly different from phase space an…
Models, predictions, and experimental measurements of far-infrared NH3-laser dynamics and comparisons with the Lorenz-Haken model
1995
Dynamics of the intensity and optical field amplitude of a coherently pumped far-infrared NH3-laser are measured and characterized. The experimental findings in certain parameter ranges closely follow the dynamics of the Lorenz model and its generalization for laser systems. Similarities and some specific differences are found in geometrical or statistical characterizations of the attractors. The experimental results are also consistent with the results of a model of optically pumped three-level lasers which takes into account the presence of a multiplicity of velocity groups as well as three-level coherence effects. For a certain region in parameter space, this far more complex model with …
The 2 + 1 Kepler problem and its quantization
2001
We study a system of two pointlike particles coupled to three dimensional Einstein gravity. The reduced phase space can be considered as a deformed version of the phase space of two special-relativistic point particles in the centre of mass frame. When the system is quantized, we find some possibly general effects of quantum gravity, such as a minimal distances and a foaminess of the spacetime at the order of the Planck length. We also obtain a quantization of geometry, which restricts the possible asymptotic geometries of the universe.
Dissipative soliton pulsations with periods beyond the laser cavity round trip time
2005
We review recent results on periodic pulsations of the soliton parameters in a passively mode-locked fiber laser. Solitons change their shape, amplitude, width and velocity periodically in time. These pulsations are limit cycles of a dissipative nonlinear system in an infinite-dimensional phase space. Pulsation periods can vary from a few to hundreds of round trips. We present a continuous model of a laser as well as a model with parameter management. The results of the modeling are supported with experimental results obtained using a fiber laser. © World Scientific Publishing Company.
Bifurcations of Links of Periodic Orbits in Mathieu Systems
2000
We prove that orbits escape from infinity, and that therefore the sphere S can be considered as its phase space. If the parameter δ is large enough, the system is non-singular MorseSmale, and its periodic orbits define a Hopf link. As δ decreases, the system undergoes some bifurcations that we describe geometrically. We relate the bifurcation orbits to periodic orbits continued from the linear Mathieu equation.
Classical Chern–Simons Mechanics
2001
We are interested in a completely integrable Hamiltonian system \((\mathscr{M}_{2N},\omega,H).\) Local coordinates on the 2N-dimensional phase space \(\mathscr{M}_{2N}\) are denoted by η a = (p, q), a = 1, 2, … 2N and the symplectic 2-form ω is given by