On the B→Xs ll decays in general supersymmetric models

We analyze the inclusive semileptonic decays B→X_s l⁺l⁻ in the framework of the supersymmetric standard model with non-universal soft-breaking terms at GUT scale. We show that the general trend of universal and non-universal models is a decreasing of branching ratio (BR) and increasing of energy asymmetry (AS). However, only non-universal models can have chances to get very large enhancements in BR and AS, corresponding to large (negative) SUSY contributions to the b→sγ amplitude.     

The contribution of Bc mesons to the search for B → τ ντ decays at LEP

We study the contribution of B_c mesons to the search for B → τν_τ decays. We find that at LEP the contributions from B_u and B_c mesons can be comparable. This observation can have a relevant impact on the extraction of constraints on new physics (such as charged-Higgs contributions) from current LEP limits on B → τν final states. Inclusion of the B_c contribution can reduce the current L3 limit on tan β/M_H from 0.38 GeV⁻¹ (90% CL) down to 0.27 GeV⁻¹ (90% CL).     

Non-1/mb power suppressed contributions to inclusive B → Xsll decays

We compute non-perturbative contributions to B → X_sl⁺l⁻ that are not explicitly suppressed by powers of the b-quark mass. They are proportional to and arise from an interference between the free-quark amplitude and high order terms in the matrix element of the four-quark operator s⁻γ^μ(1 − γ₅)cc^−βγ_μ(1 − γ₅)b_β. This correction is found to be small over most of the dalitz plot except near the charm threshold. Unfortunately, the perturbative computation we have performed is invalid near charm threshold and we do not except to see the structure found at lowest order reproduced in the data. We conclude that these non-perturbative contributions do not significantly modify the previous analysis of B → X_sl⁺l⁻.     

Polarization analysis of the Raman spectrum of As2S3 crystals

We present the first complete series of polarized Raman spectra of orpiment crystals and the corresponding possible symmetry assignments of the phonon peaks within the layer model structure. We observe new peaks and a low frequency mode which could be a rigid layer vibration. We discuss briefly on the possible implications of some inconsistencies between the expected and the observed results.     

Perturbative QCD correction to the B → π transition form factor

We report on the perturbative O(_s) correction to the light-cone QCD sum rule for the B → π transition form factor f⁺. The correction to the product f_Bf⁺ in leading twist approximation is found to be about 30%, that is similar in magnitude to the corresponding O(_s) correction in the two-point sum rule for f_B. The resulting cancellation of large QCD corrections in f⁺ eliminates one important uncertainty in the sum-rule prediction for this form factor.     

On the corrections of pole dominance in B→π/v

In the framework combining the heavy quark expansion and chiral symmetry for light quarks, we identify a class of corrections to the dominant vector meson pole diagram for B→π/v, in the vicinity of the zero pion recoil point. We also give a qualitative estimate of these effects, using higher states exchanges with couplings constrained by current algebra and PCAC.     

Argon ion laser-induced BaS BΣ-AΣ, A′Π, aΠ, and XΣ fluorescence spectra: Analysis of A A′, A a, and A′ a perturbations

The 333.6-, 351.1-, and 363.8-nm lines of a cw argon ion laser are found to coincide with the BaS B¹Σ⁺-X¹Σ⁺ (12, 0) R(17), (6, 0) P(35), and (3, 0) R(125) transitions, respectively. Fluorescence transitions from the laser-prepared upper levels terminating in X¹Σ⁺ V = 0–28, A¹Σ⁺ V = 1–3, A′¹Π V = 1–13, and a³Π₁ V = 3–12 are assigned. These results are combined with a previous analysis of the extensively perturbed BaS A¹Σ⁺-X¹Σ⁺ system [R. F. Barrow, W. G. Burton, and P. A. Jones, Trans. Farad. Soc.67, 902–906 (1971)]. Every observed perturbation of the BaS A¹Σ⁺ state is electronically and vibrationally assigned. The levels a³Π₀ V = 10–13, a³Π₁ V = 12–14, a³Π₂ V = 15, and A′¹Π V = 10–13 are sampled via their perturbations of A¹Σ⁺ V = 0–2. Although the mutual interactions of the a³Π, A′¹Π, and A¹Σ⁺ states approach Hund's case (c) limit, a complete deperturbation is performed from a case (a) starting point. Of the five lowest energy electronic states of BaS, only b³Σ⁺ remains uncharacterized. Principal deperturbed molecular constants are (in cm⁻¹, 1σ uncertainties in parentheses):

Full-size image

     

Photo-induced changes in the infrared vibrational spectrum of evaporated As2S3

Photo-induced changes in the infrared spectrum of amorphous, evaporated As₂S₃ films are described. The results are interpreted in terms of the photopolymerization of As₄S₄ molecular units and sulfur chains into an As₂S₃ glassy network. The role of photo-induced charged states in the polymerization process is discussed.     

Measurement of the average polarization of B produced by polarized muons in the μ + C → νμ + B reaction

The average polarization of ¹²B produced by the capture of polarized muons in ¹²C has been measured using recoil implantation techniques. From the result we deduce the average polarization of the ¹²B ground state ¹²B(0) corresponding to the ¹²C → ¹²B(0) Gamow-Teller reaction: J_μ(0) = 0.43 ± 0.10. The sizeable deviation of this polarization from the value of 2/3, characteristic of a “bare” 0⁺ → 1⁺ process, is a fair evidence for induced axial-vector interaction(s) in muon capture. The ratio of the induced pseudoscalar and the axial-vector coupling constants is deduced to be: g^μ_P/g^μ_A = 12 ± 5.     

The emission spectrum of B2

The emission spectrum of B₂ was reinvestigated under high resolution. Six bands of ¹¹B₂ (0-0, 1-1, 1-0, 2-1, 3-2, and 0–1) as well as four bands of ¹⁰B¹¹B (0-0, 1-0, 2-1, and 3-2) were rotationally analysed. Accurate rotational and vibrational constants were obtained. The triplet character of the transition (${}^3\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{?}}\text{-X}{}^3\text{Σ}{}_{\mathrm{g}}{}^{\mathrm{?}}$) was unambiguously established for the first time and spin-spin interaction constant is obtained for the excited state.     

The absorption spectrum of the Ag2 molecule

The high dispersion absorption spectrum of the Ag₂ molecule has been photographed in the ～5300–1500-Å region. Observations include the previously reported A ← X, B ← X, C ← X, D ← X, and E ← X transitions and a new H ← X transition which occurs in the vacuum ultraviolet. Extensive spectral blending precluded detailed rotational analyses, but the band structures are consistent with $\text{ΔΩ}\text{= 0}$ and $\text{ΔΩ}\text{≥1}$ for D-X and C-X, respectively. The H state is perturbed and probably predissociated. The following molecular constants (in cm^?1) were obtained from fitting bandhead data to the usual expressions:

     

13.

LiBX₂ (B=Ga, In; X= S, Se, Te)光学性质与力学性质的第一性原理计算          下载免费PDF全文

马天慧  庄志萍  任玉兰 《物理学报》2012,61(19):197101-197101

采用基于第一性原理的赝势平面波方法系统地计算了LiBX₂ (B= Ga, In; X= S,Se,Te) 晶体的光学性质与力学性质. 由禁带宽度推断出晶体抗激光损伤阈值的大小顺序为LiGaS₂ > LiInS₂ > LiGaSe₂ > LiInSe₂ > LiGaTe₂ > LiInTe₂. 六种晶体在常压下均满足机械力学稳定性要求, 且铟化合物可塑性及延展性强于镓化合物. 这些晶体的静态电介电常数 ε₁(0)、静态折射率n(0)和双折射率Δn 理论计算值与实验值相符. LiGaS₂, LiInS₂, LiGaSe₂, LiInSe₂和LiGaTe₂五种化合物双折射率较高, 并且它们的吸收谱与反射谱在中远红外区是透过的, 因此可推断出这五种化合物可以成为优异的中远红外非线性光学材料.     

14.

The ground state rotational spectrum of SO₂F₂     

M. Rotger  V. Boudon  L. Margulès  H. Mäder  H.S.P. Müller 《Journal of Molecular Spectroscopy》2003,222(2):172-179

The analysis of the ground state rotational spectrum of SO₂F₂ [K. Sarka, J. Demaison, L. Margulès, I. Merke, N. Heineking, H. Bürger, H. Ruland, J. Mol. Spectrosc. 200 (2000) 55] has been performed with the Watson’s Hamiltonian up to sextic terms but shows some limits due to the A and S reductions. Since SO₂F₂ is a quasi-spherical top, it can also be regarded as derived from an hypothetical XY₄ molecule. Thus we have developed a new tensorial formalism in the O(3)⊃T_d⊃C_2v group chain (M. Rotger, V. Boudon, M. Loëte, J. Mol. Spectrosc. 216 (2002) 297]. We test it on the ground state of this molecule using the same experimental data (10 GHz-1 THz region, J up to 99). Both fits are comparable even if the formalisms are slightly different. This paper intends to establish a link between the classical approach and the tensorial formalism. In particular, our tensorial parameters at a given order of the development are related to the usual ones. Programs for spectrum simulation and fit using these methods are named C_2vTDS. They are freely available at the URL:http://www.u-bourgogne.fr/LPUB/c2vTDS.html.     

15.

A precision measurement of the branching fraction B(τ → hπν_τ) from CLEO II     

Alan J. Weinstein 《Nuclear Physics B - Proceedings Supplements》1995,40(1-3)

     

16.

Thermally and photo-induced changes in the valence states of vapour-deposited As₂S₃ films: A comparative photoemission study of As₂S₃ and As₄S₄     

T. Takahashi  Y. Harada 《Solid State Communications》1980,35(2):191-194

During thermal annealing or light irradiation, the changes in the valence states of vapour-deposited As₂S₃ and As₄S₄ films were observed by UPS. The experimental results reveal that an as-deposited As₂S₃ film contains considerable numbers of As₄S₄ molecular units, which polymerize or cross link to form a As₂S₃ glassy network on annealing or irradiation.     

17.

Weak decays of the B _c meson to B _s and B mesonsin the relativistic quark model     

D. Ebert  R. N. Faustov  V. O. Galkin 《The European Physical Journal C - Particles and Fields》2003,32(1):29-43

Semileptonic and non-leptonic decays of the B _c meson to B _s and B mesons, caused by the quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c and spectator quark is used to simplify calculations while the final s and d quarks in the B _s and B mesons are treated relativistically. The decay form factors are explicitly expressed through the overlap integrals of the meson wave functions in the whole accessible kinematical range. The obtained results are compared with the predictions of other approaches.Received: 14 August 2003, Revised: 3 September 2003, Published online: 7 November 2003     

18.

On the emission band spectrum of the Ne₂ molecule in the visible and near infrared spectral region     

V. V. Gritsyna  T. S. Kijan  A. G. Koval  Ya. M. Fogel 《Optics Communications》1974,10(4):320-322

The emission spectrum of a polymer film formed on a metallic target bombarded by Ne⁺ ions is compared with the absorption spectrum of the Ne₂ molecule. From this comparison follows that the emission spectrum of the polymer film is the spectrum of the Ne₂ molecule.     

19.

Area-selective epitaxy of GaAs by migration-enhanced epitaxy with As₂ and As₄ arsenic sources     

A. Kawaharazuka  I. Yoshiba  Y. Horikoshi 《Applied Surface Science》2008,255(3):737-739

We demonstrate area-selective epitaxy by migration-enhanced epitaxy with As₂ and As₄ as arsenic sources. The distinct whisker structure growing in [1 1 1]B direction is obtained when employing As₂ as an arsenic source, while (1 1 1)B facet is formed with As₄. The difference in the facet formation can be explained by the formation of As-trimer, which significantly reduces the growth rate of the (1 1 1)B surface. With As₂, area-selective epitaxy can be achieved at lower arsenic pressure condition, where less As-trimers are formed. Therefore, growth in the [1 1 1]B direction is enhanced.     

20.

Study on B → φK * and B _d → φK _S decays in a flavor changing Z′ model     

ShuaiWei Wang  JinShu Huang  TaiPing Song  GongRu Lu 《中国科学G辑(英文版)》2008,51(9):1245-1253

We study the polarization anomaly of the B _d → φK ^*0 decay and the time-dependent CP asymmetry S _φKS of the B _d → φK _S decay in a Z′ model associated with flavor changing neutral currents at the tree level. We obtain the results of 0.0113 < ξ < 0.0127 and 0.0226 < ξ < 0.0255 for the two decay processes when setting ξ _LL = ξ _RL = ξ _LR = ξ _RR = ξ, ξ _LL = ξ _RL = ξ, and ξ _LR = ξ _RR = 0, respectively. These results are consistent with the constraints and assumptions on the model parameters in some references. Supported by the National Natural Science Foundation of China (Grant No. 10575029), the Natural Science Foundation of Henan Province of China (Grant No. 0611050300), the Natural Science Foundation of Henan Provincial Educational Committee (Grant No. 2007140013), and the High-qualified Talents Scientific Research Startup Foundation of Nanyang Normal University (Grant No. nytc2006k92)     

State	Te	ωc	Xωt
X	0.0	192.0	0.58
B	35 838.6	151.8	0.87
C	37 631.6	171.0	0.84
D	39 014.5	168.2	1.20
E	40 159.9	146.1	1.58
H	58 273.1	165.9	2.46

LiBX2 (B=Ga, In; X= S, Se, Te)光学性质与力学性质的第一性原理计算

采用基于第一性原理的赝势平面波方法系统地计算了LiBX₂ (B= Ga, In; X= S,Se,Te) 晶体的光学性质与力学性质. 由禁带宽度推断出晶体抗激光损伤阈值的大小顺序为LiGaS₂ > LiInS₂ > LiGaSe₂ > LiInSe₂ > LiGaTe₂ > LiInTe₂. 六种晶体在常压下均满足机械力学稳定性要求, 且铟化合物可塑性及延展性强于镓化合物. 这些晶体的静态电介电常数 ε₁(0)、静态折射率n(0)和双折射率Δn 理论计算值与实验值相符. LiGaS₂, LiInS₂, LiGaSe₂, LiInSe₂和LiGaTe₂五种化合物双折射率较高, 并且它们的吸收谱与反射谱在中远红外区是透过的, 因此可推断出这五种化合物可以成为优异的中远红外非线性光学材料.     

The ground state rotational spectrum of SO2F2

The analysis of the ground state rotational spectrum of SO₂F₂ [K. Sarka, J. Demaison, L. Margulès, I. Merke, N. Heineking, H. Bürger, H. Ruland, J. Mol. Spectrosc. 200 (2000) 55] has been performed with the Watson’s Hamiltonian up to sextic terms but shows some limits due to the A and S reductions. Since SO₂F₂ is a quasi-spherical top, it can also be regarded as derived from an hypothetical XY₄ molecule. Thus we have developed a new tensorial formalism in the O(3)⊃T_d⊃C_2v group chain (M. Rotger, V. Boudon, M. Loëte, J. Mol. Spectrosc. 216 (2002) 297]. We test it on the ground state of this molecule using the same experimental data (10 GHz-1 THz region, J up to 99). Both fits are comparable even if the formalisms are slightly different. This paper intends to establish a link between the classical approach and the tensorial formalism. In particular, our tensorial parameters at a given order of the development are related to the usual ones. Programs for spectrum simulation and fit using these methods are named C_2vTDS. They are freely available at the URL:http://www.u-bourgogne.fr/LPUB/c2vTDS.html.     

Thermally and photo-induced changes in the valence states of vapour-deposited As2S3 films: A comparative photoemission study of As2S3 and As4S4

During thermal annealing or light irradiation, the changes in the valence states of vapour-deposited As₂S₃ and As₄S₄ films were observed by UPS. The experimental results reveal that an as-deposited As₂S₃ film contains considerable numbers of As₄S₄ molecular units, which polymerize or cross link to form a As₂S₃ glassy network on annealing or irradiation.     

Weak decays of the B c meson to B s and B mesonsin the relativistic quark model

Semileptonic and non-leptonic decays of the B _c meson to B _s and B mesons, caused by the quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c and spectator quark is used to simplify calculations while the final s and d quarks in the B _s and B mesons are treated relativistically. The decay form factors are explicitly expressed through the overlap integrals of the meson wave functions in the whole accessible kinematical range. The obtained results are compared with the predictions of other approaches.Received: 14 August 2003, Revised: 3 September 2003, Published online: 7 November 2003     

On the emission band spectrum of the Ne2 molecule in the visible and near infrared spectral region

The emission spectrum of a polymer film formed on a metallic target bombarded by Ne⁺ ions is compared with the absorption spectrum of the Ne₂ molecule. From this comparison follows that the emission spectrum of the polymer film is the spectrum of the Ne₂ molecule.     

Area-selective epitaxy of GaAs by migration-enhanced epitaxy with As2 and As4 arsenic sources

We demonstrate area-selective epitaxy by migration-enhanced epitaxy with As₂ and As₄ as arsenic sources. The distinct whisker structure growing in [1 1 1]B direction is obtained when employing As₂ as an arsenic source, while (1 1 1)B facet is formed with As₄. The difference in the facet formation can be explained by the formation of As-trimer, which significantly reduces the growth rate of the (1 1 1)B surface. With As₂, area-selective epitaxy can be achieved at lower arsenic pressure condition, where less As-trimers are formed. Therefore, growth in the [1 1 1]B direction is enhanced.     

Study on B → φK * and B d → φK S decays in a flavor changing Z′ model

We study the polarization anomaly of the B _d → φK ^*0 decay and the time-dependent CP asymmetry S _φKS of the B _d → φK _S decay in a Z′ model associated with flavor changing neutral currents at the tree level. We obtain the results of 0.0113 < ξ < 0.0127 and 0.0226 < ξ < 0.0255 for the two decay processes when setting ξ _LL = ξ _RL = ξ _LR = ξ _RR = ξ, ξ _LL = ξ _RL = ξ, and ξ _LR = ξ _RR = 0, respectively. These results are consistent with the constraints and assumptions on the model parameters in some references. Supported by the National Natural Science Foundation of China (Grant No. 10575029), the Natural Science Foundation of Henan Province of China (Grant No. 0611050300), the Natural Science Foundation of Henan Provincial Educational Committee (Grant No. 2007140013), and the High-qualified Talents Scientific Research Startup Foundation of Nanyang Normal University (Grant No. nytc2006k92)