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

XTT cell viability assay to determine the cytotoxicity of TTC-based proteins.

<p>TTC-reactive REH cells (black) as well as the mock-transfected control REH cells (gray) were used to demonstrate the cytotoxicity of TTC-ETA' (<b>A</b>, ■), GrB(R201K)-TTC (<b>B</b>, ▼) and TTC-MAPTau (<b>C</b>, ●). The cells were incubated with an increasing concentration of the recombinant fusion proteins for 72 h at 37°C and 5% CO₂ followed by an XTT cell viability assay. The EC₅₀ value relative to untreated control cells (100% cell viability) and the positive control zeocin (0% cell viability) was calculated using the three-parameter dose-response curve fit equation with GraphPad Prism v5 software. The data are means ± SD of three independent experiments performed in triplicate (n = 3). Statistical significance was calculated by two-way ANOVA followed by Bonferroni’s post-hoc test (*** p < 0.001, ** p < 0.01, * p < 0.05, n.s.–not significant).</p