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本文在Ed=0.1—2.5MeV能量范围内,研究了Be9(d,p0)Be10(0),Be9(d,p1)Be10(3.368MeV),Be9(d,t0)Be8(0),Be9(d,α0)Li7(0)及Be9(d,α1)Li7(0.478MeV)诸反应。在Ed=0.150,0.220,0.401,0.706,1.005,1.301,1.484,1.750,2.000,2.250和2.500MeV共十一个能量上分别测量了这五群出射粒子在θL=10—155°区间的角分布。在θL=135°,Ed=0.1—2.5MeV,在θL=95°,Ed=0.1—2.2MeV,和在θL=112.5°,Ed=0.5—2.5MeV测量了Be9(d,p0)Be10的激发函数。在θL=135°和112.5°,Ed=1.2MeV,用较厚靶(100—300μg/cm2)测量了Be9(d,p0)Be10(0)反应的截面绝对值,结果为σ(p0)(θL=135°)=1.60mb/sr,σ(p0)(θL=112.5°)=1.55mb/sr。这样就得到了在此能区内,这五群出射粒子的截面情况。对所得结果进行了一些讨论。 相似文献
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本文导出了部分U6 SU3,UN (U1)N SO7 (SU2)3同位标量因子的解析表达式. 相似文献
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用一架30厘米×30厘米×10厘米磁场为6200高斯的云室,在海拔3185米的云南落雪高山实验室拍摄了30000对照片,获得105个V0,而可以进行分类的有43个。其中有26个θ10,16个Λ0和一个θ20。本文对θ10,Λ0和一个θ20进行了研究,其结果如下:1)Q值,Q(Λ0)=(36.2±2.5)Mev,Q(θ10)=(233±11)Mev;2)平均寿命,τ(Λ0)=(3.19-0.92+2.42)×10-10秒,τ(θ10)=(1.14-0.27+0.49)×10-10秒;3)动量分布与以前的工作没有显著差别;4)N(Λ0)/N(θ10)=0.51±0.22(权衡数);5)Λ0和θ10在质心系的衰变角分布没有明显的不对称性;6)一个θ20在静止坐标系寿命为~10-9秒,衰变类型可能为θ20→π-+π++π0或者θ20→π±+μ?+ν。 相似文献
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从1955年到1957年用多板云室进行了两次V0粒子实验,共得V0约550个。按α-∈方法分类为Λ0的67个,为θ0的44个。其中产生于Pb板的Λ058个、θ038个;产生于Al板的Λ09个、θ06个。对这些V0粒子进行分析,得到下列结果。1.Λ0,θ0衰变时质量中心系中衰变角均匀分布。产生面与衰变面的关联角均匀分布。无自旋>1/2的迹象。2.对Pb核中出来的Λ0衰变看不出因宇称不守恒引起的不对称角分布。Al中产生的Λ0有不对称的倾向。3.由动量分布和产生角分布看,在产生重介子与超子对时超子多向后去。4.得平均寿命τ(Λ0)=(3.39-0.440.63)×10-10秒,τ(θ0)=(0.86-0.160.26)×10-10秒。5.N(Λ0)/N(θ0)~1.4 6.估计整个奇异粒子产生截面可合0.8mb/核子。对Pb,Al都合。7.按V0佔次粒子总数比例看,Pb原子核对产生V0来讲比Al原子核有效。 相似文献
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新发现的J(3100)及ψ(3700)粒子可能可以按SU6(1)×SU3(2)模型或SU8模型分类。本文用引进等效层子次强作用的方法,研究这两个模型中多重态的次强质量分裂,得到了一系列有新自由度的粒子的质量关系。由于本文对等效层子作用的具体形式未作没有太大根据的取舍,所以,结果与模型的关系比较直接。本工作的结果还表明,完全可以用一个统一的等效层子作用去描写重子及介子的次强质量分裂,而不与现有的实验值冲突。 相似文献
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本文用最近发展的神经网络拟合方法[Chin. J. Chem. Phys. 34,825 (2021)]构造了一个新的涉及苯硫酚1πσ*态-介导光解的1ππ*和1πσ*态耦合非绝热势能面. 势能面包含了解离过程中的三个关键振动模式,即S-H伸缩、弯曲和扭转振动. 由于单双激发态运动方程耦合簇方法具有简单、效率高、精度高的优点,采用激发态运动方程耦合簇方法计算了苯硫酚激发态1ππ*和1πσ*的绝热能量. 神经网络拟合绝热激发态S1和S2态的均方根误差分别为0.89和1.33 meV,表明神经网络方法具有很高的拟合精度. 在构建非绝热势能面的过程中,仅利用了体系绝热势能,避免了非常耗时的非绝热耦合计算,极大地提高了效率. 为了检测新的非绝热势能面的可靠性,本文进一步展开了苯硫酚光解非绝热动力学模拟. 动力学计算得到的S1振电态00和31的寿命与实验和之前的理论结果均吻合,验证了基于激发态运动方程耦合簇绝热能量构建的非绝热势能面的可靠精确性,并可进一步应用到实际大分子体系中. 相似文献
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本文利用高分辨的里德堡态氘原子标识-交叉分子束装置,研究了碰撞能为4.5∽6.5 kcal/mol范围内Cl(2P)[Cl(2P3/2)和Cl*(2P1/2)]与D2的反应. 虽然自旋轨道激发态反应Cl*(2P1/2)+D2在波恩-奥本海默(B-O)近似下本应是禁阻的,但实验中观测到了该反应的贡献. 通过测量靠近后向的碰撞能相关的微分散射截面连线,发现低碰撞能下的产物主要来自于B-O近似禁阻的反应Cl*+D2. 随着碰撞能的提高,自旋轨道基态反应Cl+D2的反应性增加明显要比自旋轨道激发态反应Cl*+D2更快,并且在高碰撞能下成为产物的主要来源. 实验结果表明:在低碰撞能下,Cl*中自旋轨道激发态的额外能量,可以帮助B-O近似禁阻的反应Cl*+D2越过势垒;然而当碰撞能接近和高于反应势垒时,B-O近似允许的反应Cl+D2占主导地位. Cl/Cl*+D2反应中B-O近似有效性的特征与其同位素反应Cl/Cl*+H2是一致的. 相似文献
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The 9ΛBe1 strangeness analogue states (SAS) for 9Be (g.s.) are calculated for the configuration , using a LS basis, a procedure known to be accurate for the nucleus 8Be, leading to the prediction of three distinct SAS, a T =0 state at Λ energy 7.7 MeV, and two other states, with T = 0 and T = 1, rather closely degenerate and lying 11.5 MeV higher than the first. The origin of this degeneracy is investigated in detail and these calculations are related with earlier work done within an SU(6) χ (Sakata SU(3)) ? (spin SU(2)) framework. The corresponding supersymmetric state of 9ΛBe1 is also calculated and discussed. 相似文献
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It is well known that the MIC–Kepler problem, an extension of the three-dimensional Kepler problems, admits the same dynamical and symmetry groups as the Kepler problem. This paper aims to study dynamical and symmetry groups of the SU(2) Kepler problem, where the SU(2) Kepler problem is defined to be the dynamical system reduced from the eight-dimensional conformal Kepler problem through an SU(2) symmetry and turns out to be an extension of the five-dimensional Kepler problem. It is shown that the SU(2) Kepler problem admits a dynamical group SO*(8) and that the phase space of the SU(2) Kepler problem is symplectomorphic with a co-adjoint orbit of SO*(8), on which the Kirillov–Kostant–Souriau form is defined. It is further shown that the subgroups, SU(4), SU*(4), and Sp(2)×SR5, of SO*(8) provide the symmetry groups, SU(4)/Z2SO(6), SU*(4)/Z2SO0(1,5), and (Sp(2)×SR5)/Z2SO(5)×SR5, of the SU(2) Kepler problem with negative, positive, and zero energies, respectively, where ×S denotes a semi-direct product. Furthermore, constants of motion for the SU(2) Kepler problem are found together with their Poisson brackets. The symmetry Lie algebra formed by constants of motion is shown to be isomorphic with so(6)su(4), so(1,5)su*(4), or so(5)SR5sp(2)SR5, depending on whether the energy is negative, positive, or zero, where S denotes a semi-direct sum. These Lie algebras are subalgebras of so*(8)so(2,6). 相似文献
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Tie -zhong Li 《International Journal of Theoretical Physics》1989,28(2):169-182
The grand unified theories (GUT) of the simple Lie groups including extraZ bosons are discussed. There are onlySU
5+m,SO
6+4n, andE
6 under our hypothesis. First we give a general discussion forSU
5+m, then forSU
6 andSU
7 for illustration. We use15 +6
* +6
* fermion representations inSU
6 but not with the fermion content, Yukawa coupling, and the hierarchy of other authors. We suggest that there is a series of clans of particles. These clans consist of the extraZ bosons and the corresponding fermions of the scale. 相似文献
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E.H Auerbach A.J Baltz C.B Dover A Gal S.H Kahana L Ludeking D.J Millener 《Annals of Physics》1983,148(2):381-435
A comprehensive shell-model approach to Λ-hypernuclear spectroscopy in the p shell is developed. The available data on the spectra of 9ΛBe, 12ΛC, 13ΛC, 14ΛN and 16ΛO are interpreted in this framework, leading to constraints on the residual ΛN interaction and the one-body Λ-nucleus potential. The mechanism for the formation of Λ hypernuclei via the (K?, π?) reaction is treated in the relativistic distorted wave approximation, with careful attention paid to Fermi-averaging of the elementary K?n → π?Λ amplitude and recoil corrections. Departures from the simple weak coupling picture, arising from configuration mixing, are emphasized. This leads to approximate dynamical symmetries in hypernuclei which are forbidden in ordinary nuclei by the Pauli principle. Further experiments in the p shell are suggested which may reveal other aspects of ΛN interactions. 相似文献
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In the framework of Quark-Gluon-String Model developed recently in ITEP we calculate spectra of charmed particlesD,D s,Λc,Ξc,Ωc in hadron-hadron collisions taking into account the decays ofS-wave resonances like D*,Ds *,Σc,Σc *,Ξc *,Ξc ′, and Ωc *. We describe the bulk of the existing data onD, D*, adΛ c production in πp andpp collisions and predict the yield of charmed particlesin Σ?p and Ξ?p reactions at hyperon beam energies of 340 GeV/c and 600 GeV/c. Because of significant production of baryon resonances our predictions for unfavored fragmentation differ from predictions of other models which do not take resonance production into account. 相似文献
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Isard Dunietz 《Zeitschrift fur Physik C Particles and Fields》1992,56(1):129-143
CP violation can be studied in modes of charmed or bottom baryons when a decay process is compared with its charge-conjugated partner. It can show up as a rate asymmetry and in a study of other decay parameters. Neither tagging nor time-dependences are required to observeCP violation with modes of baryons, in contrast to the conventionalB 0 modes. Numerous modes of bottom baryons have the potential to show largeCP-violating effects within the Standard Model. Those effects can be substantial for modes with aD 0, which is seen in a final state that can also be fed from a \(\bar D^0 \) . For instance, a comparison of theΛ b→Λ CP 0 with the \(\bar \Lambda _b \to \bar \Lambda D_{CP}^0 \) process can show sizeableCP violation. HereD CP o denotesCP eigenstates ofD 0, which occur at a few percent. Six related processes, such asΛ b→ΛD 0, \(\Lambda _b \to \Lambda \bar D^0 \) ,Λ b→Λ CP 0 , and their charge-conjugated counterparts, can extract ?, which is the most problematic angle of the unitarity triangle and which is conventionally probed with theB s→ρ0 K S asymmetry. HereD 0 andD ?0 are identified by their charged kaon or lepton. We predictB(Λ b→ΛD 0)~10?5, thusB(Λ b→Λ CP 0 )~10?7. Under favourable circumstances,CP violation can occur at the few tens of percent level. Thus 102–103 Λ b→Λ CP 0 decays start probing ?. Tables list many additional modes with typical branching ratios at the 10?5–10?6 level, with large detection efficiencies (in contrast to theD CP 0 ), and with potentially largeCP-violating effects, such as Ξ b 0 →ΛΨ, Λ?, ΛK*0; Ξ b ? →ΛK(*)?, Ξ?Ks, Ξ?K*0, Ω b ? →Ξ?φ, Ξ?ρ0, ΛK(*)?, ΩKs, Ω?K*0. 相似文献
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The branching ratio is calculated for Λ8Li decay to the (2+) 8Be1 states near 17 MeV, using intermediate coupling wave functions for Λ8Li and for the relevant 8Be1 states. It is pointed out that this ratio is sensitive primarily to a mixing angle ? in the Λ8Li wave function. Within one standard deviation, the data allow two ranges (+0.05 to +0.25 rad and +1.10 to +1.25 rad) for the value of ?. The further requirement that there also be acceptable agreement between the angular distribution expected for the subsequent decay and the data, shifts these allowed ranges for ?, to (+0.13 to 0.40) rad and (+0.9 to +1.2) rad. It is predicted that the dominant transition should be to 8Be1 (16.6 MeV), as is observed to be the case, rather than to 8Be1 (16.9 MeV). The interpretation of these values for ? is discussed in some detail and their implications for intermediate coupling shell-model calculations of Λ-hypernuclear wave functions are considered. 相似文献
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Variational Monte-Carlo calculations have been performed for the ligh s-shell hypernuclei, namely, Λ 4 H, Λ 4 H*, and Λ 5 He. The main aim of the study has been to give more insight into the Λ-nuclear interactions. Our study shows that the three-body ANN force has a larger share in the splitting energy of Λ 4 H (0+–1+) compared to the two-body AN force. The analyses on Λ-binding to nuclear matter based on our s-shell results demonstrate that the three-body ANN correlations need to be incorporated suitably to describe these systems. 相似文献