scholarly journals Rotating Strings, Glueballs and Exotic Mesons

1982 ◽  
Vol 35 (3) ◽  
pp. 223 ◽  
Author(s):  
CJ Burden ◽  
LJ Tassie
Keyword(s):  
Angular Momentum ◽  
Rigid Body ◽  
Relativistic String ◽  
String Equation ◽  
Body Rotation ◽  
Exotic Mesons ◽  
Exotic Meson ◽  
Rigid Body Rotation

The relativistic string equation is solved for motion corresponding to rigid body rotation about the z-axis. One class of these solutions, namely the planar solutions, allows for the construction of two types of exotic meson and one type of glueball, all of which have asymptotically straight ChewFrautschi plots. The first type of meson only exists when the number of quarks or antiquarks is 4, 5, 6 or 7, whereas no such restriction applies to the second type. For each of these cases the first type of meson is energetically more favourable than the second type for a given angular momentum.

scholarly journals Additional Rigidly Rotating Solutions in the String Model of Hadrons

1984 ◽  
Vol 37 (1) ◽  
pp. 1 ◽  
Author(s):  
CJ Burden ◽  
LJ Tassie
Keyword(s):  
General Solution ◽  
Rigid Body ◽  
String Model ◽  
Azimuthal Velocity ◽  
Relativistic String ◽  
String Equation ◽  
Body Rotation ◽  
Alternative Derivation ◽  
Rigid Body Rotation ◽  
Velocity Of Light

Solutions to the relativistic string equation are found which correspond to rigid body rotation about the z-axis with azimuthal velocity greater than the velocity of light. If the solutions lie entirely in the x-y plane they are rotating epicycloids, complimentary to the hypocycloid solutions found previously. The use of a general solution to the string equation in terms of two arbitrary world-lines with null tangents provides an alternative derivation of the rigidly rotating solutions.

scholarly journals Post Main-Sequence Changes in Rotational Velocities

2004 ◽  
Vol 215 ◽  
pp. 154-155
Author(s):  
Helmut A. Abt
Keyword(s):  
Angular Momentum ◽  
Rigid Body ◽  
Main Sequence ◽  
Published Data ◽  
Body Rotation ◽  
B Stars ◽  
Rigid Body Rotation

From recent measurements of the rotational velocities of 1100 B stars and 1700 A stars, we determined the maximum periods of binaries with fully circularized orbits. Combined with published data, we derived the relation of period (days) = 0.001 age0.42 (yr). We were able to reproduce the rotational velocities of giants from v sin i of dwarfs only if rigid body rotation applies to both. However for evolutionary expansions greater than 5 the angular momentum is conserved in shells, which is reasonable physically.

Diagnostic Value of Rigid Body Rotation in Noncompaction Cardiomyopathy

2011 ◽  
Vol 24 (5) ◽  
pp. 548-555 ◽  
Author(s):  
Bas M. van Dalen ◽  
Kadir Caliskan ◽  
Osama I.I. Soliman ◽  
Floris Kauer ◽  
Heleen B. van der Zwaan ◽  
...  
Keyword(s):  
Rigid Body ◽  
Diagnostic Value ◽  
Body Rotation ◽  
Rigid Body Rotation ◽  
Noncompaction Cardiomyopathy

Reduction of residual vibrations in a rotating flexible beam with a moving payload mass

1997 ◽  
Vol 211 (1) ◽  
pp. 25-34 ◽  
Author(s):  
S Choura
Keyword(s):  
Rigid Body ◽  
Position Control ◽  
Rate Of Change ◽  
Torque Control ◽  
Flexible Beam ◽  
Control Force ◽  
Axial Motion ◽  
Body Rotation ◽  
Rigid Body Rotation ◽  
Payload Mass

The reduction of residual vibrations for the position control of a flexible rotating beam carrying a payload mass is investigated. The common practice used to find the position control of a flexible multi-link arm is to assign a torque actuator to each joint while the payload mass is kept fixed relative to the end-link during the time of manoeuvre. This paper examines the stability of the system if either the payload is freed accidentally to move along the beam during the time of manoeuvre or is allowed to span the beam in a desired path for control purposes. A candidate Lyapunov function is constructed and its time rate of change is examined. It is shown that the use of a PD (proportional plus derivative) torque control yields a convergence of residual vibration to zero, an attainment of the rigid-body rotation to a prespecified desired angle of manoeuvre and a constant velocity of the payload mass as it moves relative to the beam. For manipulation purposes, an additional control force is added to the moving actuator in order to regulate its axial motion. It is shown that allowing the axial motion of the payload mass in a prescribed manner leads to a considerable reduction of its residual vibrations as compared to the case where the payload mass is fixed to the beam tip during the time of manoeuvre. Stability is also verified through simulations of rigid-body rotation and payload axial motion track prespecified reference trajectories.

scholarly journals Rigid-body rotation of an electron cloud in divergent magnetic fields

2013 ◽  
Vol 20 (7) ◽  
pp. 073502 ◽  
Author(s):  
A. Fruchtman ◽  
R. Gueroult ◽  
N. J. Fisch
Keyword(s):  
Magnetic Fields ◽  
Rigid Body ◽  
Electron Cloud ◽  
Body Rotation ◽  
Rigid Body Rotation
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