Light-Cone Distribution Amplitudes of Light JPC=2−−J^{PC}=2^{--} Tensor Mesons in QCD

We present a study for two-quark light-cone distribution amplitudes for the $1^3D_2$ light tensor meson states with quantum number $J^{PC}=2^{--}$. Because of the G-parity, the chiral-even two-quark light-cone distribution amplitudes of this tensor meson are antisymmetric under the interchange of momentum fractions of the quark and antiquark in the SU(3) limit, while the chiral-odd ones are symmetric. The asymptotic leading-twist LCDAs with the strange quark mass correction are shown. We estimate the relevant parameters, the decay constants $f_T$ and $f_T^\perp$, and first Gegenbauer moment $a_1^\perp$, by using the QCD sum rule method. These parameters play a central role in the investigation of $B$ meson decaying into the $2^{--}$ tensor mesons.Comment: 18 pages, 3 Figure

Light-Cone Distribution Amplitudes of Light JPC=2−−J^{PC}=2^{--} Tensor Mesons in QCD

We present a study for two-quark light-cone distribution amplitudes for the $1^3D_2$ light tensor meson states with quantum number $J^{PC}=2^{--}$. Because of the G-parity, the chiral-even two-quark light-cone distribution amplitudes of this tensor meson are antisymmetric under the interchange of momentum fractions of the quark and antiquark in the SU(3) limit, while the chiral-odd ones are symmetric. The asymptotic leading-twist LCDAs with the strange quark mass correction are shown. We estimate the relevant parameters, the decay constants $f_T$ and $f_T^\perp$, and first Gegenbauer moment $a_1^\perp$, by using the QCD sum rule method. These parameters play a central role in the investigation of $B$ meson decaying into the $2^{--}$ tensor mesons.Comment: 18 pages, 3 Figure

Stochastic self-assembly of incommensurate clusters

We examine the classic problem of homogeneous nucleation and growth by deriving and analyzing a fully discrete stochastic master equation. Upon comparison with results obtained from the corresponding mean-field Becker-D\"{o}ring equations we find striking differences between the two corresponding equilibrium mean cluster concentrations. These discrepancies depend primarily on the divisibility of the total available mass by the maximum allowed cluster size, and the remainder. When such mass incommensurability arises, a single remainder particle can "emulsify" or "disperse" the system by significantly broadening the mean cluster size distribution. This finite-sized broadening effect is periodic in the total mass of the system and can arise even when the system size is asymptotically large, provided the ratio of the total mass to the maximum cluster size is finite. For such finite ratios we show that homogeneous nucleation in the limit of large, closed systems is not accurately described by classical mean-field mass-action approaches.Comment: 5 pages, 4 figures, 1 tabl

Deep shower interpretation of the cosmic ray events observed in excess of the Greisen-Zatsepin-Kuzmin energy

We consider the possibility that the ultra-high-energy cosmic ray flux has a small component of exotic particles which create showers much deeper in the atmosphere than ordinary hadronic primaries. It is shown that applying the conventional AGASA/HiRes/Auger data analysis procedures to such exotic events results in large systematic biases in the energy spectrum measurement. SubGZK exotic showers may be mis-reconstructed with much higher energies and mimick superGZK events. Alternatively, superGZK exotic showers may elude detection by conventional fluorescence analysis techniques.Comment: 22 pages, 5 figure

Preparation of Dicke States in an Ion Chain

We have investigated theoretically and experimentally a method for preparing Dicke states in trapped atomic ions. We consider a linear chain of $N$ ion qubits that is prepared in a particular Fock state of motion, $|m>$. The $m$ phonons are removed by applying a laser pulse globally to the $N$ qubits, and converting the motional excitation to $m$ flipped spins. The global nature of this pulse ensures that the $m$ flipped spins are shared by all the target ions in a state that is a close approximation to the Dicke state \D{N}{m}. We calculate numerically the fidelity limits of the protocol and find small deviations from the ideal state for $m = 1$ and $m = 2$. We have demonstrated the basic features of this protocol by preparing the state \D{2}{1} in two $^{25}$Mg$^+$ target ions trapped simultaneously with an $^{27}$Al$^+$ ancillary ion.Comment: 5 pages, 2 figure

The Effect of Acetaminophen on Oxidative Modification of Low-Density Lipoproteins in Hypercholesterolemic Rabbits

Oxidative modification of low-density lipoproteins (LDL) contributes to the pathology of atherosclerosis. Antioxidants may protect LDL against oxidative modification. Acetaminophen, a widely used analgesic and antipyretic agent, has significant antioxidant properties. However, there is little evidence to suggest that acetaminophen acts as an antioxidant for LDL oxidation in vivo. In this study, we investigated the in vivo effect of acetaminophen on LDL oxidation in hypercholesterolemic rabbits. The oxidative modification of LDL was identified by conjugated dienes and thiobarbituric acid-reactive substances (TBARS). In the cholesterol group which rabbits were fed a diet contained 1% g cholesterol for 8 weeks, TBARS contents and conjugated diene levels in the plasma and isolated LDL samples significantly increased compared with the control rabbits (p<0.05). However, in the cholesterol + acetaminophen group, the TBARS contents and conjugated diene levels were significantly lower than that of the cholesterol group (p<0.05). The results from in vitro studies also demonstrated that the LDL isolated from serum was oxidized by Cu++ ions and this oxidation reduced in the presence of acetaminophen. The reduced oxidative modification of LDL by acetaminophen may be of therapeutic value in preventing the development and progression of atherosclerosis

^{59}Co NMR evidence for charge ordering below T_{CO}\sim 51 K in Na_{0.5}CoO_2

The CoO$_{2}$ layers in sodium-cobaltates Na$_{x}$CoO$_{2}$ may be viewed as a spin $S=1/2$ triangular-lattice doped with charge carriers. The underlying physics of the cobaltates is very similar to that of the high $T_{c}$ cuprates. We will present unequivocal $^{59}$Co NMR evidence that below $T_{CO}\sim51 K$, the insulating ground state of the itinerant antiferromagnet Na$_{0.5}$CoO$_{2}$ ($T_{N}\sim 86 K$) is induced by charge ordering.Comment: Phys. Rev. Lett. 100 (2008), in press. 4 figure

Inelastic diffraction and color-singlet gluon-clusters in high-energy hadron-hadron and lepton-hadron collisions

It is proposed, that ``the colorless objects'' which manifest themselves in large-rapidity-gap events are color-singlet gluon-clusters due to self-organized criticality (SOC), and that optical-geometrical concepts and methods are useful in examing the space-time properties of such objects. A simple analytical expression for the $t$-dependence of the inelastic single diffractive cross section $d\sigma/dt$ ($t$ is the four-momentum transfer squared) is derived. Comparison with the existing data and predictions for future experiments are presented. The main differences and similarities between the SOC-approach and the ``Partons in the Pomeron (Pomeron and Reggeon)''-approach are discussed.Comment: 12 pages, 2 figure