Search results for "KINEMATICS"
showing 10 items of 481 documents
Relativistic Kinematics and Phase Space
2015
Here we present a list of the most important formulae needed for calculating relativistic collisions and decays. It includes one-to-two and one-to-three body decays, and the two-to-two scattering process both in the center of mass and laboratory frames. It also includes simplified general formulae of one, two and three-body Lorentz invariant phase space. No explicit calculation is performed, however the reader is highly encouraged to reproduce the results presented here.
Fractional mechanical model for the dynamics of non-local continuum
2009
In this chapter, fractional calculus has been used to account for long-range interactions between material particles. Cohesive forces have been assumed decaying with inverse power law of the absolute distance that yields, as limiting case, an ordinary, fractional differential equation. It is shown that the proposed mathematical formulation is related to a discrete, point-spring model that includes non-local interactions by non-adjacent particles with linear springs with distance-decaying stiffness. Boundary conditions associated to the model coalesce with the well-known kinematic and static constraints and they do not run into divergent behavior. Dynamic analysis has been conducted and both…
The influence of Fermi motion on the comparison of the polarization transfer to a proton in elastic e→p and quasi-elastic e→A scattering
2019
Abstract A comparison between polarization-transfer to a bound proton in quasi-free kinematics by the A ( e → , e ′ p → ) knockout reaction and that in elastic scattering off a free proton can provide information on the characteristics of the bound proton. In the past the reported measurements have been compared to those of a free proton with zero initial momentum. We introduce, for the first time, expressions for the polarization-transfer components when the proton is initially in motion and compare them to the 2H data measured at the Mainz Microtron (MAMI). We show the ratios of the transverse ( P x ) and longitudinal ( P z ) components of the polarization transfer in H 2 ( e → , e ′ p → …
Physical model, theoretical aspects and applications of the flight of a ball in the atmosphere. Part I: Modelling of forces and torque, and theoretic…
1991
A model of the forces and the torque operating on a ball that is flying with rotation in the atmosphere of the Earth, and the resulting system of ordinary differential equations, are derived from mechanics and aerodynamics. The system of equations allows the theoretical aspects of the flight of a ball, such as the boundedness of its kinetic energy, the curvature of the orbit or the velocity function, to be investigated using certain transformations of the variables. The solutions of the corresponding ordinary or boundary value problems, computed numerically, are used to treat certain tasks in international ball games, for example, the maximum and minimum velocities of a volleyball service.
Kinematic relative velocity with respect to stationary observers in Schwarzschild spacetime
2013
We study the kinematic relative velocity of general test particles with respect to stationary observers (using spherical coordinates) in Schwarzschild spacetime, obtaining that its modulus does not depend on the observer, unlike Fermi, spectroscopic and astrometric relative velocities. We study some fundamental particular cases, generalizing some results given in other work about stationary and radial free-falling test particles. Moreover, we give a new result about test particles with circular geodesic orbits: the modulus of their kinematic relative velocity with respect to any stationary observer depends only on the radius of the circular orbit, and so, it remains constant.
Radio source evolution and the interplay with the host galaxy
2019
There is compelling evidence showing that extragalactic jets are a crucial ingredient in the evolution of host galaxies and their environments. Extragalactic jets are well collimated and relativistic, both in terms of thermodynamics and kinematics at sub-parsec and parsec scales. They generate strong shocks in the ambient medium, associated with observed hotspots in FRII radio galaxies, and carve cavities that are filled with the shocked jet flow, dragging a large fraction of the interstellar gas along, in the form of slow, massive outflows within the host galaxies. In this paper, I discuss relevant processes associated to jet evolution in the frame of FRI-FRII dichotomy. In particular, I f…
Coulomb excitation of exotic nuclei at the R3B-LAND setup
2012
Exotic Ni isotopes have been measured at the R3B-LAND setup at GSI in Darmstadt, using Coulomb excitation in inverse kinematics at beam energies around 500 MeV/u. As the experimental setup allows kinematically complete measurements, the excitation energy was reconstructed using the invariant mass method. The GDR and additional low-lying strength have been observed in 68Ni, the latter exhausting 4.1(1.9)% of the E1 energy-weighted sum rule. Also, the branching ratio for the non-statistical decay of the excited 68Ni nuclei was measured and amounts to 24(4)%.
Correlations between isospin dynamics and Intermediate Mass Fragments emission time scales: a probe for the symmetry energy in asymmetric nuclear mat…
2012
We show new data from the $^{64}$Ni+$^{124}$Sn and $^{58}$Ni+$^{112}$Sn reactions studied in direct kinematics with the CHIMERA detector at INFN-LNS and compared with the reverse kinematics reactions at the same incident beam energy (35 A MeV). Analyzing the data with the method of relative velocity correlations, fragments coming from statistical decay of an excited projectile-like (PLF) or target-like (TLF) fragments are discriminated from the ones coming from dynamical emission in the early stages of the reaction. By comparing data of the reverse kinematics experiment with a stochastic mean field (SMF) + GEMINI calculations our results show that observables from neck fragmentation mechani…
Absolute kinematics of radio source components in the complete S5 polar cap sample I. First and second epoch maps at 8.4 GHz
2001
We observed the thirteen extragalactic radio sources of the S5 polar cap sample at 8.4 GHz with the Very Long Baseline Array, on 1997.93 and 1999.41. We present the maps from those two epochs and briefly discuss the morphological changes experimented by some of the radio sources in the 1.4 yr elapsed. These results correspond to the first two epochs at 8.4 GHz of a program directed to study the absolute kinematics of the radio source components of the members of the sample by means of phase delay astrometry at 8.4, 15 and 43 GHz.
MOJAVE: MONITORING OF JETS IN ACTIVE GALACTIC NUCLEI WITH VLBA EXPERIMENTS. VII. BLAZAR JET ACCELERATION
2009
We discuss acceleration measurements for a large sample of extragalactic radio jets from the Monitoring Of Jets in Active Galactic Nuclei with VLBA Experiments (MOJAVE) program, which studies the parsec-scale jet structure and kinematics of a complete, flux-density-limited sample of active galactic nuclei (AGNs). Accelerations are measured from the apparent motion of individual jet features or 'components' which may represent patterns in the jet flow. We find that significant accelerations are common both parallel and perpendicular to the observed component velocities. Parallel accelerations, representing changes in apparent speed, are generally larger than perpendicular acceleration that r…