Boron electrical activation in dual B+ + N+ + and B+ + Ar+ ion-implanted silicon

Silicon wafers were implanted with 40 keV B⁺ ions and then with 50 keV N⁺ or 100 keV Ar+ ions to doses from 1.2 x 1014 to 1.2 x 1015 cm^–2. The implanted samples were studied using the Hall effect and standard van der Pauw methods. The dependences of the sheet resistivity and the sheet concentration of charge carriers on the annealing temperature in the range from 700 to 1300 K were obtained. Models describing the influence of additional implantation of nitrogen and argon ions on the process of boron electrical activation during annealing are proposed.     

The break-up reactionp+d→p+p+n

The three-particle reactionp+d→p+p+n has been investigated at a deuteron bombarding energy of 52.0 MeV. Single counter experiments as well as coincidence measurements have been carried out. The laboratory angular distribution of the break-up reaction and the total break-up cross-section have been determined by means of the single counter experiments. The angular distribution for final-state interacting neutron-proton pairs was obtained by means of coincidence measurements. The coincidence experiments provide a strong evidence for very different shapes of the angular distributions for neutron-proton singlet and triplet final-state interaction.     

Observation of Au + Au → Au + Au + ρ 0 and Au + Au → Au* + Au* + ρ 0 with STAR

We report the first observation of the reactions Au + Au → Au + Au + ρ ⁰ and Au + Au → Au* + Au* + ρ ⁰ with the STAR detector. The ρ are produced at small perpendicular momentum, as expected if they couple coherently to both nuclei. We discuss models of vector meson production and the correlation with nuclear breakup, and present a fundamental test of quantum mechanics that is possible with the system.     

Bremsstrahlung of soft photons in the reaction p + p → π+ + d + γ

The limit theorem of Low is used to construct the amplitude of the soft bremsstrahlung accompanying the reaction p + p ⁺ + d. The obtained amplitude is expressed in terms of the amplitudes of the nonradiative process.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 29–32, December, 1970.     

Elastic π + p and π + π + scattering at LHC

We discuss the possibility of measuring leading neutron production at the LHC. These data could be used to extract from it π ⁺ p and π ⁺ π ⁺ cross sections. In this note we give some estimates for the case of elastic cross sections and discuss related problems and prospects.     

Observation of the decay B+ --> K+K-pi+

We report the observation of charmless hadronic decays of charged B mesons to the final state K{+}K{-}pi{+}. Using a data sample of 347.5 fb{-1} collected at the Upsilon(4S) resonance with the BABAR detector, we observe 429+/-43 signal events with a significance of 9.6sigma. We measure the inclusive branching fraction B(B{+}-->K{+}K{-}pi{+})=[5.0+/-0.5(stat)+/-0.5(syst)]x10{-6}. Inspection of the Dalitz plot of signal candidates shows a broad structure peaking near 1.5 GeV/c{2} in the K+K- invariant mass distribution. We find the direct CP asymmetry to be consistent with zero.     

锰原子的二步多光子与三步三光子共振电离研究

激光共振电离技术是痕量分析中的重要手段之一。文章以速率方程理论为基础,对锰原子的激光共振电离过程进行了分析,讨论了电离过程中各级激发光功率密度及激光作用时间对电离效率的影响;提出了根据所要求的电离效率和激光作用时间计算所需要的各激发光或电离激光的功率密度的方法;得到了饱和激发或饱和电离的规律及阈值条件。研究发现,在激光作用时间为10 ns时,锰原子饱和电离的激光强度阈值基本都在108 W·cm-2的量级,只有“1+1”双色双共振低三个量级;而“1+1”和“1+1+1”饱和激发的激光强度阈值则在102～103 W·cm-2量级;并且随着激光作用时间的增加,各过程的饱和激发和饱和电离的激光强度阈值将单调减少。