A note on the mass splitting of K*(892)

Belle Collaboration reported a new observed value of K*-(892) mass by studying τ- → Ksπ-γτ decay, which is significantly different from the current world average value given by Particle Data Group 2006.Motivated by this new data, we revisit the issue on the K*0(892)-K*±(892) mass splitting. Our theoreticalestimation favors the new measurement by Belle Collaboration. Therefore further experimental efforts are urgently needed to improve our understanding of these issues.     

A note on the mass splitting of K*(892)

Belle Collaboration reported a new observed value of K*-(892) mass by studying τ- → KSπ-ντ decay, which is significantly different from the current world average value given by Particle Data Group 2006. Motivated by this new data, we revisit the issue on the K*0(892)-K*±(892) mass splitting. Our theoretical estimation favors the new measurement by Belle Collaboration. Therefore further experimental efforts are urgently needed to improve our understanding of these issues.     

在BEPCⅡ/BESⅢ上测量K((892)质量劈裂的Monte Carlo研究

对BEPCⅡ BESⅢ上的J ψ→K±K (892 ) 和J ψ→K0 K (892 ) 0 过程进行了MonteCarlo模拟,对测量K (892 )的质量劈裂的可行性进行了研究.在BESⅢ探测器的设计指标下,采用6×10 8J ψ数据,若输入K (892)0 和K(892)±的质量差为6 0 0MeV ,经过BESⅢ模拟和拟合后的质量差则是5 79±0 16±0 13MeV ,其中第一项误差为统计误差,第二项误差为系统误差.这表明,BESⅢ的建造将为精确测量K (892 )质量劈裂提供极佳机遇.     

Electromagnetic Masses Anomaly of K*(892) in the Massive Yang-Mills Theory

Electromagnetic mass difference between neutral K^* and charged K^* has been calculated in the U(3)_L×U(3)_R chiral field theory of mesons. It has been revealed that the on-Abelian gauge structure of the massive Yang-Mills Lagrangian obeyed by K^* plus VMD (vector meson dominance) causes the EM-mass of neutral one larger than charged one. Experiment supports this anomaly effect.     

金核——金核与质子-质子对撞中矢量介子K0(892)和φ(1020)的自旋排列

We present the preliminary results on the spin alignment matrix element ρ₀₀ for vector mesons K^*0(892) and φ(1020) in mid-central (20%—60%) Au+Au and p+p collisions at s_NN=200GeV. The values of ρ₀₀ with respect to reaction plane in Au+Au collisions are 0.36±0.02(stat)±0.13(sys) for K^*0(892) and 0.38±0.01 (stat)±0.04 (sys) for φ(1020). No evident global spin alignment with respect to reaction plane is observed in the measured p_T region up to 5GeV/c with current sensitivity. ρ₀₀ with respect to the production plane of the vector meson is also measured for K^*0(892) and φ(1020) in Au+Au collisions, and for φ(1020) in p+p collisions. No significant difference for the ρ₀₀ between Au+Au and p+p collisions is observed with our data sample.     

Study of K*(892)0 and φ (1020) meson production in proton-proton and Pb-Pb collisions at $\sqrt{{s}_{NN}}$=2.76 TeV

In this paper, we describe a study of charged particle yield as a function of p_T for K^*(892)⁰ and φ (1020) mesons in proton-proton (pp) and Pb-Pb collisions at $\sqrt{{s}_{NN}}$=2.76 TeV in the central rapidity region of ∣y∣<0.5, in a p_T range of 0<p_T <15 GeV c⁻¹ in pp collisions and in a p_T range of 0<p_T<20 GeV c⁻¹ in Pb-Pb collisions. We also investigated a very important ratio, the nuclear modification factor, to study the effects of the medium in the most central region, i.e. 0%-5% centrality. For data simulation, we used the EPOS-LHC and EPOS-1.99 models. To check the validity of these models’ simulations, we compared the data obtained from these Monte Carlo simulation programs with ALICE experimental data for $\sqrt{{s}_{NN}}$=2.76 TeV. It was concluded that the models’ predictions for the φ-meson in pp and for the most central Pb-Pb collisions disagreed with the ALICE data, and that the difference increased with p_T. This may be connected with the essential role of collective parton behaviors which could not have been taken into account by the models. For K^*0 mesons, both programs gave almost the same predictions, and with p_T in the interval p_T>3 GeV c⁻¹, the predictions were very close to the experimental data. Both models gave higher predictions for the soft p_T interval and lower predictions for the hard interactions. The values of the R_AA distributions were lower than unity and both models were very close to the ALICE data. It is very interesting that the models were not able to describe the p_T distributions, but they gave good predictions for their ratios. This may possibly be due to parton collective behaviors. We observed some additional suppression of K^*0 at low values of p_T with respect to φ-mesons, which may be related to the role of the masses of the particles in soft interactions. The rising trend for R_AA in the region from p_T =10 GeV c⁻¹ to 20 GeV c⁻¹ observed by the ALICE experiment was absent for the φ-mesons.     

K Shell Fluorescence Parameters by Impact of 5.96 keV Photons on Ti and Its Compounds

K shell fluorescence parameters of pure Ti and some of its compounds have been determined experimentally using an Ultra-LEGe detector with resolution 150 eV at 5.9 keV. The samples were excited 5.96 keV photons emitted from a 55Fe radioisotope source with 50 mCi activity. The experimental values of the K shell fluorescence parameters have been compared with the experimental and theoretical values available in the literature for pure Ti.     

日冕物质抛射引起地磁扰动的分类预报

对1997—2003年期间引起地磁扰动的72个加速日冕物质抛射(CME)事件和69个减速CME事件进行了特性分析，并针对经行星际闪烁(IPS)认证的32个加速CME引起的地磁扰动事件和32个减速CME引起的地磁扰动事件分类建立了新的从属函数μ_T和新的磁扰开始时间修正项, 经验证预报效果得到显著提高.对于加速CME引起的地磁扰动事件，磁扰开始时间的预报值T_pre与观测值T_obs比较，相对误差ΔT_pre/T_obs≤10%的事件占总事件数的21.86%；ΔT_pre/T_obs≤30%的事件为78.13%；而ΔT_pre/T_obs>50%的事件为9.36%；对于减速CME引起的地磁扰动事件相对误差ΔT_pre/T_obs≤10%的事件占总事件数的25.00%；ΔT_pre/T_obs≤30%的事件为84.37%；而ΔT_pre/T_obs>50%的事件仅为3.13%.这表明该预报方法对空间灾害性事件的磁扰动的定量预报具有很大的现实可能性. 关键词： 日冕物质抛射 地磁扰动 从属函数     

Study on decays of DsJ *(2317) and DsJ(2460) in terms of the CQM model

Based on the assumption that D_sJ ^*(2317) and D_sJ(2460) are the (0⁺,1⁺) chiral partners of D_s and D^* _s, we evaluate the strong pionic and radiative decays of D_sJ ^*(2317) and D_sJ(2460) in the constituent quark meson (CQM) model. Our numerical results of the relative ratios of the decay widths are reasonably consistent with the data. PACS 13.25.Ft; 12.38.Lg; 12.39.Fe; 12.39.Hg     

腔内波片产生的Nd∶YAG激光纵模分裂规律研究

简要介绍了激光纵模分裂的基本原理，研究了腔内含有1个和2个1/4波片时产生Nd∶YAG激光纵模分裂的规律。实验结果表明：在1064nm Nd∶YAG激光的腔内放置一个1/4波片时，每一激光纵模分裂为2个正交的线偏振模，在波片表面垂直于激光光线的条件下，纵模分裂量（即频率差或波长差）恰好等于激光纵模间隔的一半；当在Nd∶YAG激光腔内沿垂直光线方向平行放置2个1/4波片时，也能产生纵模分裂现象，其纵模分裂量取决于2波片快（慢）轴之间的夹角。在0°～ 90°范围内调节角度，可使纵模分裂量在一个激光纵模间隔内线性调谐。实验结果与理论分析相吻合。     

The analysis of N-glycolylneuraminic acid(NeuGc) of hepatoma tissue and K562 cell ferritins using HPLC and mass spectrometry

Ferritin is an iron-storage protein and its serum level is known to increase in the patient of with inflammation and malignant tumor. To further elucidate the difference between ferritins from normal human liver tissue and that of cancer cells, their sialic acids were analyzed. The Western blot analysis and the cytochemical staining using anti-NeuGc antiserum indicated that ferritins from the human hepatocarcinoma tissue and malignant K562 cells contain NeuGc, but that from the normal liver does not. The result was also confirmed by HPLC analysis and MALDI-TOF/MS analysis of sialic acids which were derivatized by the DMB method. It was also shown that the sialic acid content in hepatocarcinoma ferritin was much higher than that in the normal liver ferritin. These results suggest that normal and cancerous liver ferritins are qualitatively and quantitatively different in sialylation. In addition, K562 cells were shown to express NeuGc even if the cells were cultured in serum-free media which lack NeuGc. This is of interest from the current concept that expression of NeuGc in human cells is due to uptake and utilization of exogenous NeuGc.     

Bayesian inference on isospin splitting of nucleon effective mass from giant resonances in ~(208)Pb

From a Bayesian analysis of the electric dipole polarizability,the constrained energy of isovector giant dipole resonance,the peak energy of isocalar giant quadrupole resonance,and the constrained energy of isocalar giant monopole resonance in ~(208)Pb,we extract the iso scalar and isovector effective masses in nuclear matter at saturation density p_0 as m_(s,0)~*/m=0.87_(-0.04)~(+0.04) and m_(v,0)~*/m=0.78_(-0.05)~(+0.06),respectively,at 90% confidence level.The constraints obtained on m_(s,0)~* and m_(v,0)~* lead to a positive iso spin splitting of nucleon effective mass in asymmetric nuclear matter of iso spin asymmetry δ at p_0 as m_(n-p)~*/m=(0.20_(-0.14)~(+0.15))δ.In addition,the symmetry energy at the subsaturation density p~*=0.05 fm~(-3) is determined to be E_(sym)(p~*)=16.7±1.3 MeV at 90% confidence level.     

Experimental verification of a zero-dimensional model of the kinetics of XeCl* discharges by XeCl*(B)-, XeCl*(C)-, and Xe2Cl*-density measurements

Absolutely calibrated emission spectroscopy has been used to determine the particle number densities of XeCl^*(B), XeCl^*(C), and Xe₂Cl^* in a small scale Ne/Xe/HCl discharge with well-defined current and voltage pulses for a wide range of parameters. The measured particle number densities could be reproduced quite well by numerical model calculations using the rate-coefficient values of Quiñones et al. [1] for the quenching of XeCl^*(B,C) by Ne, Xe, and 2Xe, but 3.0 × 10^–31 cm⁶/s for the formation of Xe₂Cl^* by (Ne + Xe)-quenching. For the electron quenching, we recommend a rate coefficient value of 3.2 × 10^–8 cm³/s. From the equilibrium ratio of the particle number densities of XeCl^*(C) and XeCl^*(B), the energy separation between these states has been estimated to be 72 ± 33 cm^–1 with the B state placed above the C state.     

Interfacial width and shape fluctuations and extensions of the Gaussian model of capillary waves

Interfacial density fluctuations are studied at the level of the Gaussian model of capillary waves by means of density functional theory. We consider nonrigid fluctuations and arrive at exact Triezenberg-Zwanzig-type expressions for new interfacial coefficients. These include a width tension, a width rigidity, and other coefficients linked to both shape and width distortions. We find for these coefficients magnitudes of the same orders as those of their tangential counterparts. The corresponding capillary-wave model describes the effect of fluctuations when the density is slowly varying, and the recognition of the additional quantities and their roles may help in the understanding of ellipsometric studies near critical points.     

用IRIS/AP-ICP-AES法对大气降水中K、Na、Ca、Mg同时测定的研究

本文采用ＩＣＰ－ＡＥＳ法同时测定降水中Ｋ、Ｎａ、Ｃａ、Ｍｇ的含量。根据各元素的特性，为选择合适的入射功率、雾化压力、提升量以及试样的酸度等条件进行了探索，并且，用选定的最佳条件对样品进行测试。方法简便、快速、准确。测试结果的相对标准偏差均小于３％。     

Angular momentum dependence of the giant dipole resonance width in excited nuclei of mass

Gamma ray spectra in the energy range of 4–25 MeV were measured in the reaction ²⁸Si + ¹²⁴Sn at E(²⁸Si) 150 MeV in coincidence with low energy γ-multiplicities. The spectra were analysed using a simulated Monte Carlo CASCADE code. The centroid energy and width of the giant dipole resonance were extracted for various multiplicity windows. The average angular momentum and temperature of the final states populated after the giant dipole photon emission range from 25 and 1.5 MeV to 56 and 1.3 MeV, respectively. The extracted widths are almost constant for the lower multiplicity windows and show an increase of 1.4 MeV at the highest window. The nuclei are expected to be near the liquid drop regime and the experimental results are not inconsistent with the liquid drop behaviour.     

掺杂硅纳米梁谐振频率的理论模型及分子动力学模拟

通过理论计算与模拟,研究分析了P元素替代掺杂单晶硅纳米梁的谐振频率.计算模拟了两端固支单晶硅纳米梁的谐振频率随尺寸、掺杂浓度与温度的变化.通过对计算结果与模拟结果的分析得到:单晶硅纳米梁的谐振频率随着硅纳米梁长度尺寸的增大而减小;硅纳米梁的谐振频率随着掺杂浓度的增大而增大,但变化趋势并不明显;最后考虑了温度效应,发现掺杂硅纳米梁的谐振频率随着温度的增大而减小,但从谐振频率的数值来看,硅梁的谐振频率随温度的变化趋势并不明显,即温度对硅梁谐振频率基本无影响.由此得出结论:掺杂浓度与温度对硅纳米梁谐振频率的影响很小,影响单晶硅纳米梁谐振频率的主要因素是尺寸大小,掺杂单晶硅纳米梁的谐振频率具有尺寸效应.     

Measurement of neutron cross sections and resonance parameters of ~(169)Tm below 100 eV

The neutron total cross-sections of thulium (~(169)Tm) were measured in the neutron energy region from 0.01 eV to 100 eV by using the time-of-flight method at the Pohang Neutron Facility, which consists of an electron linac, a water-cooled tantalum target with a water moderator, and a 12 m time of flight path. Two thulium plates with different thicknesses were used for the neutron transmission measurement. The background level was determined by using a notch-filter of Co, In, and Cd sheets. The present measurement was compared with the previous ones, and a new set of resonance parameters of ~(169)Tm isotope was obtained from the transmission rate by using the SAMMY code, with a comparison with the recommended parameters by Mughabghab.