Λb→Λc\Lambda_b \to \Lambda_c Form Factors from QCD Light-Cone Sum Rules

In this work, we calculate the transition form factors of $\Lambda_b$ decaying into $\Lambda_c$ within the framework of light-cone sum rules with the distribution amplitudes (DAs) of $\Lambda_b$-baryon. In the hadronic representation of the correlation function, we have isolated both the $\Lambda_c$ and the $\Lambda_c^*$ states so that the $\Lambda_b \rightarrow \Lambda_c$ form factors can be obtained without ambiguity. We investigate the P-type and A-type current to interpolate the light baryons for a comparison since the interpolation current for the baryon state is not unique. We also employ three parametrization models for DAs of $\Lambda_b$ in the numerical calculation. We present the numerical predictions on the $\Lambda_b \rightarrow \Lambda_c$ form factors and the branching fractions, the averaged forward-backward asymmetry , the averaged final hadron polarization and the averaged lepton polarization of the $\Lambda_b \to \Lambda_c \ell\mu$ decays, as well as the ratio of branching ratios $R_{\Lambda_c}$, and the predicted $R_{\Lambda_c}$ can be consistent with the LHCb data.Comment: 22 pages, 2figur

不同年龄和性别精神分裂症患者脑白质扩散张量成像的临床研究*

Objective: Diffusion tensor imaging (DTI) was used to analyze the changes of white matter fiber FA in patients with schizophrenia of different ages and genders, and to explore the reference of clinical imaging. Methods: Retrospective analysis of the clinical diagnosis of schizophrenia patients and healthy subjects in all 50 cases, were given routine examination of brain MRI parallel diffusion tensor imaging, comparison of different age and gender in different parts of the brain white matter changes of FA value. Results: (1) the FA values of white matter in different age groups were different between the patients and the normal group (P < 0.05). The normal group right superior frontal gyrus, left parietal lobe and left anterior cingulate gyrus of the cerebral white matter fiber FA value increased gradually before the age of 30, at the age of 30 and reached the peak gradually decreased after 30 years old. The left frontal gyrus and corpus callosum in patients with group pressure (after) of cerebral white matter fiber FA value increased gradually before the age of 30, at the age of 30 and reached the peak gradually decreased after 30 years old. (2) the FA values of white matter in different parts of male and female patients were different (P < 0.05). The white matter fiber FA in the left anterior capsule of the normal group was higher in males than in females. The FA value of bilateral occipital white matter in male patients was lower than that in female; the FA values of the central white matter in the left and right sides of the brain stem were higher in males than in females. Conclusion: the changes of FA value in the white matter of some parts of the brain in the normal group and the patient group are influenced by age and sex.  目的  运用扩散张量成像分析不同年龄和性别精神分裂症患者脑白质纤维FA值的变化，探讨临床影像学参考依据。方法  回顾性分析经临床确诊的精神分裂症患者和健康者各50例，均作颅脑MRI常规检查并行扩散张量成像，比较不同年龄和性别各部位脑白质FA值变化特点。结果  （1）患者组和正常组不同年龄各部位脑白质FA值有差异（P＜0.05）。正常组中右额上回、左顶叶及左扣带回前部脑白质纤维FA值在30岁前逐渐增高，30岁达高峰，在30岁后逐渐减少。患者组中左额上回及胼胝体压部（后）脑白质纤维FA值在30岁前逐渐增高，30岁达高峰，在30岁后逐渐减少。（2）患者组和正常组男女各部位脑白质FA值有差异（P＜0.05）。发现正常组中左侧内囊前肢脑白质纤维FA值男性较女性高。患者组中双侧枕叶脑白质纤维FA值男性较女性低；脑干左右侧中心脑白质FA值男性较女性高。结论  正常组和患者组大脑某些部位脑白质纤维FA值量的变化受年龄、性别的影响

Almost Automorphic Random Functions in Probability

We introduce the notion of almost automorphic random functions in probability. Some basic and fundamental properties of such functions are established

3-Eth­oxy­carbonyl-2-hy­droxy-6-meth­oxy-4-methyl­benzoic acid

The title compound, C12H14O6, a substituted isophthalic acid monoester which was isolated from the lichen Thamnolia vermicularis var. subuliformis, displays intra­molecular carbox­yl–meth­oxy O—H⋯O and hy­droxy–carboxyl O—H⋯O hydrogen-bonding inter­actions. The terminal methyl group of the ethyl ester is disordered over two sets of sites with occupancies of 0.599 (19) and 0.401 (19)

Quantum interface between frequency-uncorrelated down-converted entanglement and atomic-ensemble quantum memory

Photonic entanglement source and quantum memory are two basic building blocks of linear-optical quantum computation and long-distance quantum communication. In the past decades, intensive researches have been carried out, and remarkable progress, particularly based on the spontaneous parametric down-converted (SPDC) entanglement source and atomic ensembles, has been achieved. Currently, an important task towards scalable quantum information processing (QIP) is to efficiently write and read entanglement generated from a SPDC source into and out of an atomic quantum memory. Here we report the first experimental realization of a quantum interface by building a 5 MHz frequency-uncorrelated SPDC source and reversibly mapping the generated entangled photons into and out of a remote optically thick cold atomic memory using electromagnetically induced transparency. The frequency correlation between the entangled photons is almost fully eliminated with a suitable pump pulse. The storage of a triggered single photon with arbitrary polarization is shown to reach an average fidelity of 92% for 200 ns storage time. Moreover, polarization-entangled photon pairs are prepared, and one of photons is stored in the atomic memory while the other keeps flying. The CHSH Bell's inequality is measured and violation is clearly observed for storage time up to 1 microsecond. This demonstrates the entanglement is stored and survives during the storage. Our work establishes a crucial element to implement scalable all-optical QIP, and thus presents a substantial progress in quantum information science.Comment: 28 pages, 4 figures, 1 tabl

Holographic Storage of Biphoton Entanglement

Coherent and reversible storage of multi-photon entanglement with a multimode quantum memory is essential for scalable all-optical quantum information processing. Although single photon has been successfully stored in different quantum systems, storage of multi-photon entanglement remains challenging because of the critical requirement for coherent control of photonic entanglement source, multimode quantum memory, and quantum interface between them. Here we demonstrate a coherent and reversible storage of biphoton Bell-type entanglement with a holographic multimode atomic-ensemble-based quantum memory. The retrieved biphoton entanglement violates Bell's inequality for 1 microsecond storage time and a memory-process fidelity of 98% is demonstrated by quantum state tomography.Comment: 5 pages, 4 figures, accepted by Phys. Rev. Let

Ground Movement Analysis Based on Stochastic Medium Theory

In order to calculate the ground movement induced by displacement piles driven into horizontal layered strata, an axisymmetric model was built and then the vertical and horizontal ground movement functions were deduced using stochastic medium theory. Results show that the vertical ground movement obeys normal distribution function, while the horizontal ground movement is an exponential function. Utilizing field measured data, parameters of these functions can be obtained by back analysis, and an example was employed to verify this model. Result shows that stochastic medium theory is suitable for calculating the ground movement in pile driving, and there is no need to consider the constitutive model of soil or contact between pile and soil. This method is applicable in practice