Two-loop amplitudes and master integrals for the production of a Higgs boson via a massive quark and a scalar-quark loop

We compute all two-loop master integrals which are required for the evaluation of next-to-leading order QCD corrections in Higgs boson production via gluon fusion. Many two-loop amplitudes for 2 -> 1 processes in the Standard Model and beyond can be expressed in terms of these integrals using automated reduction techniques. These integrals also form a subset of the master integrals for more complicated 2 -> 2 amplitudes with massive propagators in the loops. As a first application, we evaluate the two-loop amplitude for Higgs boson production in gluon fusion via a massive quark. Our result is the first independent check of the calculation of Spira, Djouadi, Graudenz and Zerwas. We also present for the first time the two-loop amplitude for gg -> h via a massive squark

The two-loop QCD amplitude gg -> h,H in the Minimal Supersymmetric Standard Model

We present the two-loop QCD amplitude for the interaction of two gluons and a CP-even Higgs boson in the Minimal Supersymmetric Standard Model. We apply a novel numerical method for the evaluation of Feynman diagrams with infrared, ultraviolet and threshold singularities. We discuss subtleties in the ultraviolet renormalization of the amplitude with conventional dimensional regularization, dimensional reduction, and the four dimensional helicity scheme. Finally, we show numerical results for scenarios of supersymmetry breaking with a rather challenging phenomenology in which the Higgs signal in the MSSM is suppressed in comparison to the Standard Model.Comment: 5 pages, 3 figure

Evaluating multi-loop Feynman diagrams with infrared and threshold singularities numerically

We present a method to evaluate numerically Feynman diagrams directly from their Feynman parameters representation. We first disentangle overlapping singularities using sector decomposition. Threshold singularities are treated with an appropriate contour deformation. We have validated our technique comparing with recent analytic results for the gg->h two-loop amplitudes with heavy quarks and scalar quarks.Comment: 8 pages, 3 figures; references added, version to appear in JHE

Balancing Europe's wind-power output through spatial deployment informed by weather regimes

ISSN:1758-679

Generation of an artificial human B cell line test system using Transpo-mAbTM technology to evaluate the therapeutic efficacy of novel antigen-specific fusion proteins

The antigen-specific targeting of autoreactive B cells via their unique B cell receptors (BCRs) is a novel and promising alternative to the systemic suppression of humoral immunity. We generated and characterized cytolytic fusion proteins based on an existing immunotoxin comprising tetanus toxoid fragment C (TTC) as the targeting component and the modified Pseudomonas aeruginosa exotoxin A (ETA') as the cytotoxic component. The immunotoxin was reconfigured to replace ETA' with either the granzyme B mutant R201K or MAPTau as human effector domains. The novel cytolytic fusion proteins were characterized with a recombinant human lymphocytic cell line developed using Transpo-mAb (TM) technology. Genes encoding a chimeric TTC-reactive immunoglobulin G were successfully integrated into the genome of the precursor B cell line REH so that the cells could present TTC-reactive BCRs on their surface. These cells were used to investigate the specific cytotoxicity of GrB(R201K)-TTC and TTC-MAPTau, revealing that the serpin proteinase inhibitor 9-resistant granzyme B R201K mutant induced apoptosis specifically in the lymphocytic cell line. Our data confirm that antigen-based fusion proteins containing granzyme B (R201K) are suitable candidates for the depletion of autoreactive B cells

Expression and characterization of TTC-based fusions proteins.

<p>(A) The TTC DNA sequence was transferred to the pMS vector system using the SfiI/NotI sites to generate pMS-EGrB(R201K)-TTC and pMS-TTC-MAPTau. Abbreviations: CMV = cytomegalovirus promoter, Ig kappa = murine signal sequence for protein secretion into the cell culture supernatant, ECS = enterokinase cleavage site, His₁₀ = polyhistidine tag, IRES = internal ribosome entry site for the co-expression of eGFP, eGFP = enhanced green fluorescent protein. (B) EGrB(R201K)-TTC and TTC-MAPTau were expressed in HEK 293T cells and purified by IMAC. The GrB-(R210K)-TTC and TTC-MAPTau proteins were separated by denaturing SDS-PAGE followed by staining with Coomassie Brilliant Blue (left). Western blot analysis (right) using anti-polyhistidine and goat anti-mouse IgG (Fc specific) antibodies revealed protein bands of the anticipated sizes for GrBR201K-TTC (80 kDa) and TTC-MAPTau (93 kDa). Lane 1—Color Prestained Protein Standard, Broad Range (11–245 k); lane 2—GrBR201K-TTC, lane 3—TTC-MAPTau. (C) EGrB(R201K)-TTC was digested with enterokinase and granzyme B activity was tested using substrate Ac-IETD-<i>p</i>NA (white circle) compared to uncleaved EGrB(R201K)-TTC (black triangle) and the mock-protein (white triangle). The enzymatic activity of the granzyme B domain was determined using a colorimetric assay and the absorbance at 405 nm was monitored for 60 min in 2-min intervals. (D) An XTT-based cell viability assay was carried out using serial dilutions of the novel TTC-fusion proteins against the mouse TTC-reactive hybridoma cell line 5E4 (72 h, 37°C, 5% CO₂). The data are means ± standard deviation (SD) of technical triplicates of three independent experiments (n = 3).</p