New Terms for Compact Form of Electroweak Chiral Lagrangian

The compact form of the electroweak chiral Lagrangian is a reformulation of its original form and is expressed in terms of chiral rotated electroweak gauge fields, which is crucial for relating the information of underlying theories to the coefficients of the low-energy effective Lagrangian. However the compact form obtained in previous works is not complete. In this letter we add several new chiral invariant terms to it and discuss the contributions of these terms to the original electroweak chiral Lagrangian.     

Two body non-leptonic decaysB →Dπ with heavy quark and chiral symmetry

We have analysed the two body non-leptonic charmed-meson decays of heavyB meson based on the factorization assumption. The transition matrix elements and the corresponding decay widths are calculated in the heavy quark and chiral symmetry limit and the Isgur-Wise function present in the expression is determined by the wave function model of Aliet al. The results obtained are quite interesting and agree reasonably well with the experimental data.     

Precession and Interference in the Aharonov–Casher and Scalar Aharonov–Bohm Effects

The ideal scalar Aharonov–Bohm (SAB) and Aharonov–Casher (AC) effect involve a magnetic dipole pointing in a certain fixed direction: along a purely time dependent magnetic field in the SAB case and perpendicular to a planar static electric field in the AC case. We extend these effects to arbitrary direction of the magnetic dipole. The precise conditions for having nondispersive precession and interference effects in these generalized set ups are delineated both classically and quantally. Under these conditions the dipole is affected by a nonvanishing torque that causes pure precession around the directions defined by the ideal set ups. It is shown that the precession angles are in the quantal case linearly related to the ideal phase differences, and that the nonideal phase differences are nonlinearly related to the ideal phase differences. It is argued that the latter nonlinearity is due to the appearance of a geometric phase associated with the nontrivial spin path. It is further demonstrated that the spatial force vanishes in all cases except in the classical treatment of the nonideal AC set up, where the occurring force has to be compensated by the experimental arrangement. Finally, for a closed space-time loop the local precession effects can be inferred from the interference pattern characterized by the nonideal phase differences and the visibilities. It is argued that this makes it natural to regard SAB and AC as essentially local and nontopological effects.     

手征夸克模型下ud四夸克态的研究(英文)

在手征SU(3)夸克模型和扩展的手征SU(3)夸克模型的框架下,用变分的方法系统地研究了同位旋为0、1,自旋宇称为0~ 、1~ 和2~ 的ud■四夸克系统6个低组态的能量.模型的参数取自以前的工作,它能很好地描述核子-核子散射相移以及核子-超子散射截面.S道相互作用的参数由拟合K介子和K~*介子的质量定出,并且考虑了具有相同量子数的态之间的态混合效应.结果表明,同位旋为0且自旋宇称为1~ 的ud■能量低于相应的K~*K~*的阈能,且该组态中KK~*的成分相当小,因此该组态的宽度可能较小,可视为一个可能的四夸克态的候选者.     

Correspondence between spin-dynamic phases and pulse program phases of NMR spectrometers

Spin state selective experiments have become very useful tools in solution NMR spectroscopy, particularly in the context of TROSY line narrowing. However, the practical implementation of such pulse sequences is frequently complicated by unexpected instrument behavior. Furthermore, a literal theoretical analysis of sequences published with specific phase settings can fail to rationalize such experiments and can seemingly contradict experimental findings. In this communication, we develop a practical approach to this ostensible paradox. Spin-dynamic design, rationalization, and simulation of NMR pulse sequences, as well as their confident and reliable implementation across current spectrometer hardware platforms, require precise understanding of the underlying nutation axis conventions. While currently often approached empirically, we demonstrate with a simple but general pulse program how to uncover these correspondences a priori in the general case. From this, we deduce a correspondence table between the spin-dynamic phases used in NMR theory and simulation on the one hand and pulse program phases of current commercial spectrometers on the other. As a practical application of these results, we analyze implementations of the original (1)H-(15)N TROSY experiment and illustrate how steady-state magnetization can be predictably, rather than empirically, added to a desired component. We show why and under which circumstances a literal adoption of phases from published sequences can lead to incorrect results. We suggest that pulse sequences should be consistently given with spin-dynamically correct (physical) phases, rather than in spectrometer-specific (software) syntax.     

Stationary optimal control of a stochastic system with stable environmental interferences

In this paper, we consider a class of nonstationary control systems. We obtain some conditions for stationary optimal controls of such systems. The results are then applied to a linear-quadratic system.     

Cooper pairs? magnetic moment in MCFL color superconductivity

We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.     

Criterion of homogeneous boiling-up of superheated liquids

It is difficult to eliminate the effect of vessel walls and impurities in practical studies of boiling-up of strongly superheated liquids. Therefore, some doubts are always cast upon validity of experiments and their agreement with the classical theory of homogeneous stationary nucleation, impairing the verification of theoretical considerations. This paper reports main results of the theory of homogeneous nucleation and presents formulas for calculating the work of formation of a critical nucleus by an incline of the accessible superheating boundary on isobars and isotherms. Matching of experimental and theoretical values of the work of formation was considered as the homogeneous boiling-up criterion. Calculations by isobars and isotherms were made for some liquids. The theoretical values of the work of formation of a critical nucleus were 1.23–4.5 times higher than the corresponding empirical values for all the liquids, i.e., they were much higher than the calculation error. Thus, boiling-up of the studied liquids was not homogeneous and, hence, it did not correspond to the classical theory of nucleation. The work was financially supported by the President of the Russian Federation (No. NSh-4429.2006.8) and the Russian Foundation for Basic Research (Grant No. 07-08-00575-a).     

Study of nucleon resonances in a chiral quark model via η productions

In this report we investigate η-meson productions on the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asym-metry for the two productions are calculated and compared with the experiment. The five known resonances S_(11)(1535), S_(11)(1650), P_(13)(1720), D_(13)(1520), and F_(15)(1680) are found to be dominant in the reaction mech-anisms in both channels. Significant contribution from a new S_(11) resonances are deduced. For the so-called "missing resonances", no evidence is found within the investigated reactions. The partial wave amplitudes for π~-p→ηn are also presented.     

Continuous measurements of stable isotopes of carbon dioxide and water vapour in an urban atmosphere: isotopic variations associated with meteorological conditions

Isotope ratios of carbon dioxide and water vapour in the near-surface air were continuously measured for one month in an urban area of the city of Nagoya in central Japan in September 2010 using laser spectroscopic techniques. During the passages of a typhoon and a stationary front in the observation period, remarkable changes in the isotope ratios of CO₂ and water vapour were observed. The isotope ratios of both CO₂ and water vapour decreased during the typhoon passage. The decreases can be attributed to the air coming from an industrial area and the rainout effects of the typhoon, respectively. During the passage of the stationary front, δ¹³C–CO₂ and δ¹⁸O–CO₂ increased, while δ²H–H₂Ov and δ¹⁸O–H₂Ov decreased. These changes can be attributed to the air coming from rural areas and the air surrounding the observational site changing from a subtropical air mass to a subpolar air mass during the passage of the stationary front. A clear relationship was observed between the isotopic CO₂ and water vapour and the meteorological phenomena. Therefore, isotopic information of CO₂ and H₂Ov could be used as a tracer of meteorological information.