Polarized 3 parton production in inclusive DIS at small x

Azimuthal angular correlations between produced hadrons/jets in high energy collisions are a sensitive probe of the dynamics of QCD at small x. Here we derive the triple differential cross section for inclusive production of 3 polarized partons in DIS at small x using the spinor helicity formalism. The target proton or nucleus is described using the Color Glass Condensate (CGC) formalism. The resulting expressions are used to study azimuthal angular correlations between produced partons in order to probe the gluon structure of the target hadron or nucleus. Our analytic expressions can also be used to calculate the real part of the Next to Leading Order (NLO) corrections to di-hadron production in DIS by integrating out one of the three final state partons.Comment: 5 pages, 6 figures; version accepted for publication in Physics Letters

Synthesis of N-Heterocycles from Donor Acceptor Cyclopropanes and Progress towards Flinderole A, B, and C

The first chapter of this thesis describes two projects, one explores the novel reactivity of quaternary donor acceptor cyclopropanes and the second one involves progress toward the total synthesis of the flinderoles A, B, and C. The first project involves the Lewis acid catalyzed nucleophilic ring opening of quaternary donor acceptor cyclopropanes with indoline. It was found that the ring opening reaction worked well with either Sc(OTf)3 or Yb(OTf)3 as the Lewis acids. The ring opened products were also able to be converted into pyrroloindoles via a manganese (III) oxidative radical cyclization reaction. Cyclopropanes bearing alkynyl, vinyl, and aryl substituents were well tolerated as well as indolines bearing substitution at the 3-position. The second project involves the application of the ring opening/cyclization reaction to synthesize the pyrroloindole scaffold of the flinderoles. The chapter also describes our efforts to complete the synthesis of the natural products, and despite many alternative routes, we were not able to access the flinderoles. The second chapter describes the Lewis acid catalyzed annulation reactions of donor acceptor cyclopropanes with vinyl azide and 2H-azirine. Surprisingly, the reaction with either the vinyl azide or 2H-azirine gave the same azabicyclic product. The reaction was also limited to cyclopropanes bearing trifluoroethyl esters instead of the common methyl esters. The reaction scope with respect to the cyclopropanes tolerated aryl, heteroaryl, vinyl, alkynyl and quaternary substituents on the cyclopropane. In both reactions, the azabicycle was obtained as a single diastereomer, which was confirmed by x-ray crystallography

Broadening of H2_2O rotational lines by collision with He atoms at low temperature

We report pressure broadening coefficients for the 21 electric-dipole transitions between the eight lowest rotational levels of ortho-H$_2$O and para-H$_2$O molecules by collisions with He at temperatures from 20 to 120 K. These coefficients are derived from recently published experimental state-to-state rate coefficients for H$_2$O:He inelastic collisions, plus an elastic contribution from close coupling calculations. The resulting coefficients are compared to the available experimental data. Mostly due to the elastic contribution, the pressure broadening coefficients differ much from line to line, and increase markedly at low temperature. The present results are meant as a guide for future experiments and astrophysical observations.Comment: 2 figures, 2 table

Feynman parametrization and Mellin summation at finite temperature

We show that the Mellin summation technique (MST) is a well defined and useful tool to compute loop integrals at finite temperature in the imaginary-time formulation of thermal field theory, especially when interested in the infrared limit of such integrals. The method makes use of the Feynman parametrization which has been claimed to have problems when the analytical continuation from discrete to arbitrary complex values of the Matsubara frequency is performed. We show that without the use of the MST, such problems are not intrinsic to the Feynman parametrization but instead, they arise as a result of (a) not implementing the periodicity brought about by the possible values taken by the discrete Matsubara frequencies before the analytical continuation is made and (b) to the changing of the original domain of the Feynman parameter integration, which seemingly simplifies the expression but in practice introduces a spurious endpoint singularity. Using the MST, there are no problems related to the implementation of the periodicity but instead, care has to be taken when the sum of denominators of the original amplitude vanishes. We apply the method to the computation of loop integrals appearing when the effects of external weak magnetic fields on the propagation of scalar particles is considered.Comment: 16 pages, 1 figure. Discussion expanded. References added. Published versio