122632442
In-medium kaon-nucleon vector interaction based on chiral effective Lagrangian
We investigate the implications of the four-nucleon terms in the chiral effective Lagrangian for the s-wave K-nucleon effective interaction. We nd that such terms play a nontrivial role in the description of symmetric nuclear matter. Our results for the kaon effective energy and in-medium K+- nucleon scattering are in agreement with the previous prediction obtained by in-medium scaling qualitatively.
122405140
Effects of Delta Degrees of Freedom on Quark Condensate in Hot and Dense Matter
The relativistic mean-field theory is applied to study the quark condensate systematically in nuclear matter at zero and finite temperature in terms of the relative importance of delta degrees of freedom. Calculations have included the high-order contributions to quark condensate in nuclear medium due to the baryon-baryon interactions. Numerical results are presented for the nuclear density up to five times larger than the normal density and temperature up to 120 MeV. It is found that the delta resonance in nuclear matter can cause substantial decreases to in-medium quark condensate.
120641266
$K^-$-Nuclear Bound States in Relativistic Mean-Field Theory
18809945
Quark mass and phase transition for strange matter
We have derived the popularly used mass parametrization formula for light quarks and modified the corresponding formula for strange quarks with the mass-densitydependent model. A simple expression for the critical density of phase transition of strange quark matter at zero temperature is thus found and its value is estimated to be over 6 times the normal nuclear density.
122969926
K− Nucleus Elastic Scattering and Momentum-Dependent Optical Potentials
The K− nucleus differential elastic scattering cross section for 12C and 40Ca at is calculated with three momentum-dependent optical potential models, which are density-dependent, relativistic mean field, and hybrid model, respectively. It is found that the forms of momentum-dependent optical potential models proposed by us are reasonable and gain success in the calculations and the momentum-dependent hybrid model is the best model for the K− nucleus elastic scattering.
124229961
A light-cone QCD inspired effective Hamiltonian model for pseudoscalar and scalar mesons
Considering the one-gluon exchange interaction and phenomenological quark confinement potential, an improved light-cone effective Hamiltonian for mesons and the corresponding radial mass eigen equations in angular momentum representation is obtained. Solving the J = 0 eigen equations numerically and using a set of adjustable parameters, the obtained solutions for ground states and radial excited states can simultaneously describe both pseudoscalar and scalar flavour-off-diagonal mesons. Some radial excited states are also predicted and wait for experimental test. More results for the vector and axial vector mesons are expected.
54926043
Thermodynamics in Loop Quantum Cosmology
Loop quantum cosmology (LQC) is very powerful to deal with the
behavior of early universe. Moreover, the
effective loop quantum cosmology gives a successful description of
the universe in the semiclassical region. We consider the apparent
horizon of the Friedmann-Robertson-Walker universe as a
thermodynamical system and investigate the thermodynamics of LQC
in the semiclassical region. The effective density and effective
pressure in the modified Friedmann equation from LQC not only
determine the evolution of the universe in LQC scenario but
also are actually found to be the thermodynamic
quantities. This result comes from the energy definition in
cosmology (the Misner-Sharp gravitational energy) and is
consistent with thermodynamic laws. We prove that within the
framework of loop quantum cosmology, the elementary equation of
equilibrium thermodynamics is still valid.
40767145
Rotating Coil Magnetic Measurement System and Measurement Results of Quadrupole Prototype for BEPCII Storage Ring
A normal quadrupole prototype magnet with 266-mm long, 105-mm aperture has been designed and fabricated by IHEP. Total of 88 quadrupole magnets are under fabrication. The multipole components, magnetic field gradient and transfer function of the quadrupole magnets were measured in September 2004, using an updated measurement system, which includes a rotating coil measurement system and a Hall Probe measurement system. This paper mainly describes the updated harmonic coil magnetic field measurement system and provides the measurement results for BEPC II quadrupole magnets
110023193
Studies of an array of PbF 2 Cherenkov crystals with large-area SiPM readout
The electromagnetic calorimeter for the new muon (g 2) experiment at Fermilab will consist of arrays of PbF2 Cerenkov crystals read out by large-area silicon photo-multiplier (SiPM) sensors. We report here on measurements and simulations using 2.0 { 4.5 GeV electrons with a 28-element prototype array. All data were obtained using fast waveform digitizers to accurately capture signal pulse shapes versus energy, impact position, angle, and crystal wrapping. The SiPMs were gain matched using a laser-based calibration system, which also provided a stabilization procedure that allowed gain correction to a level of 10 4 per hour.
118624166
Averaged null energy condition in loop quantum cosmology
Wormholes and time machines are objects of great interest in general relativity. However, to support them it needs exotic matters which are impossible at the classical level. Semiclassical gravity introduces the quantum effects into the stress-energy tensor and constructs many self-consistent wormholes. But they are not traversable due to the averaged null energy condition. Loop quantum gravity (LQG) significantly modifies the Einstein equation in the deep quantum region. If we write the modified Einstein equation in the form of the standard one but with an effective stress-energy tensor, it is convenient to analyze the geometry in LQG through the energy condition. Loop quantum cosmology (LQC), an application of LQG, has an effective stress-energy tensor which violates some kinds of local energy conditions. So it is natural that the inflation emerges in LQC. In this paper, we investigate the averaged null energy condition in LQC in the framework of the effective Hamiltonian, and we find that the effective stress-energy tensor in LQC violates the averaged null energy condition in the massless scalar field coupled model.
118459896
Correlating Quasi{Electron Relaxation with Quantum Femtosecond Magnetism in the Order Parameter Dynamics of Insulating Manganites
Institute of Electronic Structure & Laser, Foundation for Research and Technology{Hellas,Vassilika Vouton, 71110 Heraklion, Crete, Greece(Dated: September 8, 2014)Femtosecond (fs){resolved simultaneous measurements of charge and spin dynamics reveal the co-existence of two di erent quasi{particle excitations in colossal magneto-resistive (CMR) manganites,with fs and ps relaxation times respectively. Their populations reverse size above a photoexcitation{intensity{threshold coinciding with a \sudden" antiferro{to{ferromagnetic switching during <100 fslaser pulses. We present evidence that fast, metallic, mobile quasi{electrons dressed by quantum spinuctuations coexist with slow, localized, polaronic charge carriers in non{equilibrium phases. Thismay be central to CMR transition and leads to a laser{driven charge reorganization simultaneouslywith quantum fs magnetism via an emergent quantum{spin/charge/lattice transient coupling.