1,723,002 research outputs found
Calculation of N<SUP>∗++</SUP> -N<SUP>∗-</SUP> mass difference by S-matrix methods
No full textThe electromagnetic mass difference between the N∗++(pion-nucleon 3/2 resonance with T3=+3/2) and N∗-(T3=-3/2) is calculated using the recent method of Dashen and Frautschi. The calculated mass difference is (MN∗++-MN∗-)=-2.8 MeV. The experimental value is (MN∗++-MN∗-)=-0.6±5 MeV
On the hypernuclei resonant states ∧Li6,∧He<SUP>5∗</SUP>; and ∧Be<SUP>9∗</SUP>
No full textAn attempt has been made to detect narrow resonant states of ΛHe5∗ (I = 2),ΛLi6 and ΛBe9∗ (I = 1) from amongst a sample of 128 uniquely identified ΛH4 and 195 uniquely identified ΛHe5 hypernuclei produced by stopping Krmesons in a nuclear emulsion stack. From the experimental data presented, it is concluded that the production of any of these resonant states is not appreciable; upper limits of 20% and 15% are set for the proportion of ΛHe5 resulting from the decay of ΛLi6 and ΛBe9∗ respectively
The INDO/2-AHP method for excited states : Part 2. The adiabatic proton affinities of formaldehyde in <SUP>1,3</SUP>nπ<SUP>∗</SUP> and <SUP>1,3</SUP>ππ<SUP>∗</SUP> states
No full textThe gas-phase proton affinities (PA) of formaldehyde in the nπ∗ and ππ∗ states have been studied theoretically using the average hole potential (AHP) model at the INDO/2 level of approximation. The PA of H2CO is predicted to decrease in the sequence PA(1Smo PA(nππ∗) > PA(ππ∗); moreover, PA(1nπ∗) > PA(3nπ∗) and PA(1ππ∗) > PA(3ππ∗). Structurally, the protonated formaldehyde molecule is planar in the ground and ππ∗ states with non-linear arrangements of the C---O---H+ fragment, but is non-planar in the nπ∗ state with the proton lying above the molecular plane. Barriers to the internal in-plane and out-of-plane motions of the proton in the 1So, 1,3nπ and 1,3ππ∗ states of H2COH⊕ have been calculated
Linked collectors and determiners for: Review of the enigmatic genus Boalda with transfer of pulcherrima Köhler from Nephelistis and description of two new species (Lepidoptera: Noctuidae).
No full textNatural history specimen data linked to collectors and determiners held within, "Review of the enigmatic genus Boalda with transfer of pulcherrima Köhler from Nephelistis and description of two new species (Lepidoptera: Noctuidae)". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9">https://bionomia.net/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9">https://gbif.org/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9</a>. Formatted as a Frictionless Data package
Linked collectors and determiners for: Review of the enigmatic genus Boalda with transfer of pulcherrima Köhler from Nephelistis and description of two new species (Lepidoptera: Noctuidae).
No full textNatural history specimen data linked to collectors and determiners held within, "Review of the enigmatic genus Boalda with transfer of pulcherrima Köhler from Nephelistis and description of two new species (Lepidoptera: Noctuidae)". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9">https://bionomia.net/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9">https://gbif.org/dataset/48c2539e-c040-4dd2-8727-ddbf457664e9</a>. Formatted as a Frictionless Data package
Distinguishing the early and late transition states and exploring the validity of σ→σ<SUP>∗</SUP>#, σ#→σ<SUP>∗</SUP>, and σ→π<SUP>∗</SUP><SUB>C=O</SUB> concepts in diastereoselection from NBO analysis
No full textNatural bond orbital (NBO) analysis of several early TSs does not support the σ→σ∗# hypothesis. The σ→π∗C=O interaction controls the carbonyl pyramidalization that, in turn, controls the π-selectivity of a nucleophilic addition. In contrast, late TSs are devoid of σ→π∗C=O interactions, and they benefit from σ→σ∗# interactions that control π-selectivity. The evidence in favor of Anh-Felkin's σ#→σ∗ hypothesis is weak. The electron-withdrawing σC-F in the 2-fluoropropanal-LiCN TS did not align anti to the incipient bond even though there was complete conformational freedom. The initial guess for the TS in which σC-F was held anti to σ# optimized to what had lost the said geometrical relationship. Furthermore, in the TS for axial addition of LiCN to 2-ax-F-cyclohexanone, the net σ→σ∗# interaction was considerably larger than the net σ#→σ∗ interaction. The relative TS energies require that the equatorial addition of LiCN to 2-ax-F-cyclohexanone be favored over the axial addition in good compliance with the available experimental results
Linked collectors and determiners for: Collections des Herbiers d'Afrique de l'Ouest et d'Afrique Centrale.
No full textNatural history specimen data linked to collectors and determiners held within, "Collections des Herbiers d'Afrique de l'Ouest et d'Afrique Centrale". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/b2df52a4-6143-46d5-8727-f808d8e25feb">https://bionomia.net/dataset/b2df52a4-6143-46d5-8727-f808d8e25feb</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/b2df52a4-6143-46d5-8727-f808d8e25feb">https://gbif.org/dataset/b2df52a4-6143-46d5-8727-f808d8e25feb</a>. Formatted as a Frictionless Data package
Equilibrium pK<SUP>∗</SUP> of carbazole studied by the deprotonation reaction in ammoniacal aqueous media
No full textForward and backward rate constants for the excited state deprotonation reaction of carbazole in ammoniacal aqueous media were determined from both steady state (Weller's fluorescence quenching technique) and direct kinetic studies. The results establish that the equilibrium pK∗ may be significantly different from the "apparent" pK∗ obtained by the fluorometric titration method
Lepton polarization correlations in B→K<SUP>∗</SUP>τ<SUP>-</SUP>τ<SUP>+</SUP>
No full textIn this work we will study the polarizations of both leptons (τ) in the decay channel B→K∗τ-τ+. In the case of the dileptonic inclusive decay B→K∗l-l+, where apart from the polarization asymmetries of a single lepton l, one can also observe the polarization asymmetries of both leptons simultaneously. If this sort of measurement is possible then we can have, apart from decay rate, forward backward asymmetry and the six single lepton polarization asymmetries (three each for l- and l+), nine more double polarization asymmetries. This will give us a very useful tool in more strict testing of the standard model (SM) and the physics beyond. We discuss the double polarization asymmetries of the τ leptons in the decay mode B→K∗τ-τ+ within the SM and the minimal supersymmetric extension of it
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