Limits on light gravitino production and new processes with large missing transverse energy in p&pmacr; collisions at sqrt

Events collected by the Collider Detector at Fermilab (CDF) with an energetic jet plus large missing transverse energy can be used to search for physics beyond the standard model. We see no deviations from the expected backgrounds and set upper limits on the production of new processes. We consider in addition the production of light gravitinos and set a limit at 95% confidence level on the breaking scale sqrt[F]>/=217 GeV, which excludes gravitino masses smaller than 1.1x10(-5) eV/c(2).     

Transverse momentum and total cross section of e(+)e(-) pairs in the Z-boson region from p&pmacr; collisions at sqrt

The transverse momentum and total cross section of e(+)e(-) pairs in the Z-boson region of 66相似文献   

The Crystalline Sponge Method in Water

The crystalline sponge method entails the elucidation of the (absolute) structure of molecules from a solution phase using single-crystal X-ray diffraction and eliminates the need for crystals of the target compound. An important limitation for the application of the crystalline sponge method is the instability of the available crystalline sponges that can act as host crystals. The host crystal that is most often used decomposes in protic or nucleophilic solvents, or when guest molecules with Lewis basic substituents are introduced. Here a new class of (water) stable host crystals based on f-block metals is disclosed. It can be shown that these hosts not only increase the scope of the crystalline sponge method to a wider array of solvents and guests, but that they can even be applied to aqueous solutions containing hydrophilic guest molecules, thereby extending the crystalline sponge method to the important field of water-based chemistry.     

A Conformationally Frozen Peptoid Boosts CXCR4 Affinity and Anti-HIV Activity

There can be only one: Using a peptoid motif obtained by shifting the arginine side chain of a pentapeptide previously developed by Fujii et?al. to the neighboring nitrogen atom restricts the conformational freedom and yields a conformationally homogeneous peptide with a 100-fold higher binding affinity to the chemokine receptor CXCR4 in the picomolar range. Its efficiency to inhibit HIV-1 infections is also demonstrated.     

Inelastic collisions of ultracold polar LiCs molecules with caesium atoms in an optical dipole trap

We investigate collisions of ultracold polar LiCs molecules and ultracold caesium atoms. LiCs molecules are formed in an optical dipole trap by photoassociation of caesium and lithium atoms via the B(1)Π excited state followed by spontaneous emission to the X(1)Σ(+) ground state and the lowest triplet state a(3)Σ(+). The molecules are then stored together with caesium atoms in the same optical trap. Rate coefficients for the loss of molecules induced by collisions with surrounding Cs atoms are measured for molecular ensembles produced via different photoassociation resonances. The results are analyzed in terms of the unitarity limit for the inelastic rates and predictions from the universal model of Idziaszek and Julienne (Phys. Rev. Lett., 2010, 104, 113202).     

Nanosecond photofragment imaging of adiabatic molecular alignment

Adiabatic alignment of CH(3)I, induced by the anisotropic interaction of this symmetric top molecule with the intense field of a nonresonant infrared laser pulse, has been studied using velocity map imaging. We are using photodissociation imaging with pulsed nanosecond lasers to probe the distribution of the molecular axis in the laboratory space. In contrast to the commonly used probing with femtosecond laser pulses, this technique directly yields the degree of alignment over an extended space-time volume. This will be relevant for future reactive scattering experiments with laser-aligned molecules. The obtained degree of alignment, (cos?(2)θ), measured as a function of the infrared laser intensity, agrees well with a quantum calculation for rotationally cold methyl iodide. The strong infrared laser is also found to modify the photofragmentation dynamics and open up pathways to CH(3)I(+) formation and subsequent fragmentation.     

Preparation of a ready-for-injection radiopharmaceutical based on MIBI using99mTc from a centralized extraction generator

The state of trace concentrations of⁹⁵Zr–⁹⁵Nb and¹³⁴Cs was studied at an initial pH>13 in an uranyl triperoxidate medium using the electromigration method. OH^– ions governing the potential are adsorbed on the colloidal Nb(V)-hydroxide which leads to an increase in its negative electric charge; while⁹⁵Zr did not move during the procedure. However, the electrophoretic mobility of the¹³⁴Cs could be explained in terms of their agglomerations attributed to the interaction of Cs⁺ ions with water molecules to give larger aggregations.     

Radiochemical F-fluoroarylation of unsaturated α-, β- and γ-amino acids, application to a radiolabelled analogue of baclofen

Unsaturated α-, β- and γ-amino acids have been investigated as substrates for the reductive Meerwein arylation. Radical reactions of this type have been shown to be a valuable tool for the fast and efficient introduction of the 4-[¹⁸F]fluorophenyl group into precursor molecules allowing short-time syntheses of potential PET radiotracers, which would be more difficult to access by other methods.