91854570
Effects of chiral symmetry restoration in nuclear medium
117367144
Vector Meson Properties in Hot Dense Matter
53550475
Subthreshold cascade production in heavy ion collisions
Using a gauged flavor SU(3)-invariant hadronic Lagrangian, we have calculated the cross sections for the strangeness-exchange reactions in the Born approximation. These cross sections are then used in the Relativistic Vlasov-Uehling-Uhlenbeck (RVUU) transport model to study Ξ production in Ar+KCl collisions at incident energy of 1.76A GeV and impact parameter b = 3.5 fm. We find that including the contributions of hyperonhyperon scattering channels strongly enhances the yield of Ξ, leading to the abundance ratio which is essentially consistent with the recently measured value of by the HADES collaboration at GSI.
121501735
Nucleon magnetic form factors in the cloudy bag model
Abstract The nucleon magnetic moments and magnetic form factors have been calculated in the cloudy bag model. The π NN, π N Δ , γπ form factors and the CM corrections have been taken into account. We obtained very good results for these quantities.
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.
122265337
A QCD Sum Rule Approach with an Explicit Di-quark Field
We introduce a phenomenological QCD sum rule with an explicit diquark field. We investigate certain configurations of hadrons are expected to have a good diquark structure. The parameters of the model are a diquark mass $${(m_\phi)}$$ and condensate $${(\langle \phi^2\rangle)}$$ . Assuming that Λ baryons can be represented by a diquark and a spectator quark configuration, we find the sum rule works well for Λ, Λc, and Λb. We also find a duality relation between the mass and the condensate for which the parameter sets give good Borel curves. To maintain good Borel curve, a smaller diquark condensate is needed for an increased diquark mass. Using these parameter sets, we test the diquark structure in some hadrons which contain both good and bad diquark configurations.
119190806
1/2-BPS Wilson loops and vortices in ABJM model
We explore the low-energy dynamics of 1/2-BPS heavy particles coupled to the ABJM model via the Higgsing of M2-branes, with focus on physical understanding of the recently discovered 1/2-BPS Wilson loop operators. The low-energy theory of 1/2-BPS heavy particles turns out to have the U(N|N) supergauge symmetry, which explains the novel structure of the 1/2-BPS Wilson loop operator as a holonomy of a U(N|N) superconnection. We show that the supersymmetric transformation of the Wilson loop operator can be identified as a fermionic supergauge transformation, which leads to their invariance under half of the supersymmetry. We also argue that 1/2-BPS Wilson loop operators appear as 1/2-BPS vortices with vorticity 1/k. Such a vortex can be naturally interpreted as a membrane wrapping the $$ {\mathbb{Z}_t} $$ cycle once, or type IIA fundamental string.
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.
73687599
Overcoming weak intrinsic depolarizing resonances with energy-jump
In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. A polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. However, a significant amount of polarization was lost at 0+/spl nu//sub y/, 12+/spl nu//sub y/ and 36+/spl nu//sub y/, which is believed to be partially due to the coupling resonances. To overcome the coupling resonance, an energy-jump was generated by rapidly changing the beam circumference using the powerful AGS RF system. It clearly demonstrates that the novel energy-jump method can successfully overcome coupling resonances and weak intrinsic resonances.
35465935
Acceleration of polarized proton in high energy accelerators
The understanding of polarized proton acceleration in the high energy accelerator is reviewed. In high energy accelerators, snakes are needed to preserve polarization. The author analyzes the effects of snake resonances, snake imperfections, and overlapping resonances on spin depolarization. He discusses results of snake experiments at the IUCF (Indiana University Cyclotron Facility) cooler ring. The snake can be overcome by various kinds of spin depolarization resonances. These experiments pointed out that a partial snake can be used to cure the imperfection resonances in low to medium energy accelerators.<<ETX>>
122695172
Nonlinear beam dynamics experiments at the IUCF cooler ring
Results of nonlinear beam dynamics experiments at the IUCF Cooler Ring in past two years are discussed. Our experiments include studies on (1) betatron motion at 1-D resonance island, (2) linear coupling correction, (3) Hamiltonians determined experimentally from 2-D difference and sum resonances, (4) longitudinal phase space tracking, (5) beam response to RF phase modulation, (6) beam response to RF voltage modulation, (7) synchro-betatron coupling induced by dipole field modulation and (8) attractors of a weak dissipative Hamiltonian system.<<ETX>>