118665630
Neutron Skin size dependence of the nuclear binding energy
The nuclear binding energy is studied using a finite temperature density functional theory. A Skyrme interaction is used in this work. Volume, surface, and symmetry energy contributions to the binding energy are investigated. The case of neutron skin is considered in detail. The neutron skin modifies the mass $A$ dependence of various terms and $I$ dependence of the skin thickness is proportional to $I$ for the case of same central density.
17587151
Nuclear Density-Dependent Effective Coupling Constants in the Mean-Field Theory
It is shown that the equation of state of nuclear matter can be determined within the mean-field theory of $\sigma \omega$ model provided only that the nucleon effective mass curve is given. We use a family of the possible nucleon effective mass curves that reproduce the empirical saturation point in the calculation of the nuclear binding energy curves in order to obtain density-dependent effective coupling constants. The resulting density-dependent coupling constants may be used to study a possible equation of state of nuclear system at high density or neutron matter. Within the constraints used in this paper to $M^*$ of nuclear matter at saturation point and zero density, neutron matter of large incompressibility is strongly bound at high density while soft neutron matter is weakly bound at low density. The study also exhibits the importance of surface vibration modes in the study of nuclear equation of state.
118377735
Free energy versus internal energy potential for heavy quark systems at finite temperature
Using the QCD sum rule with its operator product expansion reliably determined from lattice calculations for the pressure and energy density of hot QCD matter, we calculate the strength of the $J/\ensuremath{\psi}$ wave function at the origin and find that it decreases with temperature when the temperature is in the vicinity of the transition temperature. This result is shown to follow exactly that obtained from the solution of the Schr\"odinger equation for a charm and anticharm quark pair with a temperature independent quark mass using the free energy from lattice calculations as the potential and is in sharp contrast to that using the deeper potential associated with the internal energy, which shows an enhanced strength of the $J/\ensuremath{\psi}$ wave function at the origin. Our result thus suggests that the free energy potential from lattice calculations is the appropriate heavy-quark potential for analyzing the charmonium spectrum at a finite temperature.
121434885
Nuclear Symmetry Energy with QCD Sum Rule
We calculate the nucleon self-energies in an isospin asymmetric nuclear matter using QCD sum rule. Taking the difference of these for the neutron and proton enables us to express an important part of the nuclear symmetry energy in terms of local operators. Calculating the operator product expansion up to mass dimension six operators, we find that the main contribution to the difference comes from the iso-vector scalar and vector operators, which is reminiscent to the case of relativistic mean field type theories where mesons with aforementioned quantum numbers produce the difference and provide the dominant mechanism for nuclear symmetry energy.
123700523
Comments on optical stochastic cooling
An important necessary condition for transverse phase space damping in the optical stochastic cooling with transit-time method is derived. The longitudinal and transverse damping dynamics for the optical stochastic cooling is studied. The authors also obtain an optimal laser focusing condition for laser-beam interaction in the correction undulator. The amplification factor and the output peak power of the laser amplifier are found to differ substantially from earlier publications. The required power is large for hadron colliders at very high energy.
8569497
The Chaotic Dynamical Aperture
Nonlinear magnetic forces become more important for particles in the modern large accelerators. These nonlinear elements are introduced either intentionally to control beam dynamics or by uncontrollable random errors. Equations of motion in the nonlinear Hamiltonian are usually non-integrable. Because of the nonlinear part of the Hamiltonian, the tune diagram of accelerators is a jungle. Nonlinear magnet multipoles are important in keeping the accelerator operation point in the safe quarter of the hostile jungle of resonant tunes. Indeed, all the modern accelerator designs have taken advantages of nonlinear mechanics. On the other hand, the effect of the uncontrollable random multipoles should be evaluated carefully. A powerful method of studying the effect of these nonlinear multipoles is using a particle tracking calculation, where a group of test particles are tracing through these magnetic multipoles in the accelerator hundreds to millions of turns in order to test the dynamical aperture of the machine. These methods are extremely useful in the design of a large accelerator such as SSC, LEP, HERA and RHIC. These calculations unfortunately take a tremendous amount of computing time. In this review the method of determining chaotic orbit and applying the method to nonlinear problems in accelerator physics ismore » discussed. We then discuss the scaling properties and effect of random sextupoles.« less
118620419
Background independent holographic description: from matrix field theory to quantum gravity
A bstractWe propose a local renormalization group procedure where length scale is changed in spacetime dependent way. Combining this scheme with an earlier observation that high energy modes in renormalization group play the role of dynamical sources for low energy modes at each scale, we provide a prescription to derive background independent holographic duals for field theories. From a first principle construction, it is shown that the holographic theory dual to a D-dimensional matrix field theory is a (D + 1)-dimensional quantum theory of gravity coupled with matter fields of various spins. The gravitational theory has (D + 1) first-class constraints which generate local spacetime transformations in the bulk. The (D + 1)-dimensional diffeomorphism invariance is a consequence of the freedom to choose different local RG schemes.