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V Ravindran Pankaj Agrawal Rahul Basu Satyaki Bhattacharya J Blümlein V Del Duca R Harlander D Kosower Prakash Mathews Anurag Tripathi 《Pramana》2006,67(5):983-992
This is the report of the subgroup QCD of Working Group-4 at WHEPP-9. We present the activities that had taken place in the
subgroup and report some of the partial results arrived at following the discussion at the working group meetings. 相似文献
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Acetonitrile and [D3]acetonitrile in the vicinal region of a planar AgX fiber contain linear dipole–dipole linked oligomers as shown by 1) comparison of infrared band intensity ratios in the gaseous and condensed phases and 2) remarkable plots of absorbance (C? N stretch) versus time during evaporation from an AgX planar fiber element. The plots (CH3CN 2252 cm?1, CD3CN 2262 cm?1) reveal the presence of octamers, hexamers, tetramers, and dimers along with some heptamer, trimer, and monomer structures. A novel isotope effect arises from the somewhat smaller size of the CD3CN resulting in an increase in the CN band intensity. The organized oligomers may be termed pseudocrystals and are the main components responsible for absorption intensity in the infrared spectrum of acetonitrile, on the AgX planar fiber or in an IR cell. 相似文献
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N‐Alkylacylamides in Thin Films Display Infrared Spectra of 310‐, α‐, and π‐Helices with Visible Static and Dynamic Growth Phases 下载免费PDF全文
A peptide model is a physical system containing a CONH group, the simplest being HCONHCH3, N‐methylformamide (NMF). We have discovered that NMF and N‐methylacetamide (NMA), which form hydrogen‐bonded oligomers in thin films on a planar AgX fiber, display infrared (IR) spectra with peaks like those of polypeptide helices. Structures can be assigned by their amide I maxima near 1672 (310), 1655 (310), 1653 (α), 1655 (π), and 1635 cm?1 (π), which are the first IR data for the π‐helix. Sharp peaks are an outcome of immobilization of polar species on the polar surface of silver halides. We report the first use of expanded thin‐film IR spectroscopy, in which plots of every spectrum over the amide I–II range show pauses or slow stages in the increase or decrease of absorption. These are identified as static phases followed by dynamic phases, with the incremental gain or loss of a helix turn. A general theory can be stated for such processes. Density functional calculations show that the NMA α‐helix pentamer (crystal structure geometry) is transformed into a π‐helix‐like form. For the first time, an entire sequence (310‐helix, α‐helix, π‐helix, quasiplanar species) of spectra has been recorded for NMA. 相似文献
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Berger CF Bern Z Dixon LJ Cordero FF Forde D Gleisberg T Ita H Kosower DA Maître D 《Physical review letters》2011,106(9):092001
We present the next-to-leading order (NLO) QCD results for W+4-jet production at hadron colliders. This is the first hadron-collider process with five final-state objects to be computed at NLO. It represents an important background to many searches for new physics at the energy frontier. Total cross sections, as well as distributions in the jet transverse momenta, are provided for the initial LHC energy of √s = 7 TeV. We use a leading-color approximation, known to be accurate to 3% for W production with fewer jets. The calculation uses the BLACKHAT library along with the SHERPA package. 相似文献
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We consider general constraints on baryosynthesis in low-energy SU(3) × SU(2) × U(1) theories. We find in general that phenomenologically acceptable models exist, which are unifiable at higher energies-but which all require exotic fermion content. 相似文献
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Hanna Dodiuk Edward M. Kosower Michael Ottolenghi Naomi Orbach 《Chemical physics letters》1977,49(1):174-176
The triplets generated by laser pulse excitation of N-methyl-2-N-phenylamino-6-naphthalenesulfonate (1M) and its C-protonated form, the N-methyl betaine of 6-sulfonato-3β-tetralenone N-phenylimine (2M) are distinct and apparently do not interconvert at 25°C either in dioxane-water or in glycerol, for which single pulses must be used to avoid conversion of 1M to 2M. Some parallel results are reported for the N-hydroxyethyl derivatives (1HEand2HE). 相似文献
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We confirm by explicit computation the conjectured all-orders iteration of planar maximally supersymmetric N=4 Yang-Mills theory in the nontrivial case of five-point two-loop amplitudes. We compute the required unitarity cuts of the integrand and evaluate the resulting integrals numerically using a Mellin-Barnes representation and the automated package of Czakon [Comput. Phys. Commun. 175, 559 (2006)]. This confirmation of the iteration relation provides further evidence suggesting that N=4 gauge theory is solvable. 相似文献
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