Higgs production in gluon fusion at next-to-next-to-leading order QCD for finite top mass

The inclusive Higgs production cross section from gluon fusion is calculated through NNLO QCD, including its top quark mass dependence. This is achieved through a matching of the 1/mtop expansion of the partonic cross sections to the exact large s-hat limits which are derived from k_T-factorization. The accuracy of this procedure is estimated to be better than 1% for the hadronic cross section. The final result is shown to be within 1% of the commonly used effective theory approach, thus confirming earlier findings.Comment: 28 pages, 14 figure

Effect of iloprost on contractile impairment and mitochondrial degeneration in ischemia-reperfusion of skeletal muscle

Purpose Acute lower extremity ischemia is still a main cause of mortality and morbidity in orthopedic traumatology and reconstructive surgery. In acute lower extremity ischemia, the skeletal muscles are the tissues that are the most vulnerable to ischemia. The aim of this study was to evaluate the effects of iloprost (IL) therapy on skeletal muscle contractile impairment and mitochondrial degeneration in an acute lower extremity ischemia-reperfusion rat model. Main Methods Forty Wistar albino rats were randomly divided into a control group and four experimental groups. Experimental groups were either subjected to 2 h of lower extremity ischemia followed by a 4-h reperfusion period or to 4 h of ischemia followed by an 8-h reperfusion period. Except for the animals in the control group, all animals received IL (1 ng/kg/min) or saline (1 ml/kg) by intraperitoneal infusion for 10 min immediately before reperfusion. At the end of the recording of skeletal muscle electrical activity and contractility, all rats were sacrificed by decapitation and muscle samples of lower extremity were immediately harvested for histopathologic analyses. Results After ischemia-reperfusion, a breakdown in the force–frequency curves of extensor digitorum longus muscle was observed, showing the diminished muscle contractility. However, IL significantly improved muscle contractility following injury induced by 2 h of ischemia followed by a 4-h reperfusion period. In addition, IL partially ameliorated mitochondrial degeneration in the muscle cells of ischemia groups. Conclusion This study indicates that immediate IL therapy repairs muscle damage especially after 2 h of ischemia and 4 h of reperfusion and therefore that IL improves contractile function

Jet-veto in bottom-quark induced Higgs production at next-to-next-to-leading order

We present results for associated Higgs+n-jet production in bottom quark annihilation, for n=0 and n>=1 at NNLO and NLO accuracy, respectively. We consider both the cases with and without b-tagging. Numerical results are presented for parameters relevant for experiments at the LHC.Comment: 27 pages, 13 figures, 8 table

Top-mass effects in differential Higgs production through gluon fusion at order \alpha_s^4

Effects from a finite top quark mass on differential distributions in the Higgs+jet production cross section through gluon fusion are studied at next-to-leading order in the strong coupling, i.e. $O(\alpha_s^4)$. Terms formally subleading in $1/m_t$ are calculated, and their influence on the transverse momentum and rapidity distribution of the Higgs boson are evaluated. We find that, for the differential K-factor, the heavy-top limit is valid at the 2-3% level as long as the transverse momentum of the Higgs remains below about 150 GeV.Comment: 21 pages, 12 figure

Amplitudes With Different Helicity Configurations Of Noncommutative QED

The amplitudes of purely photonic and photon{2-fermion processes of non- commutative QED (NCQED) are derived for different helicity configurations of photons. The basic ingredient is the NCQED counterpart of Yang-Mills recursion relations by means of Berends and Giele. The explicit solutions of recursion relations for NCQED photonic processes with special helicity configurations are presented.Comment: 23 pages, 2 figure

Asymptomatic giant coronary aneurysm in an adolescent with Behcet's syndrome

<p>Abstract</p> <p>Objective</p> <p>Behcet's is an idiopathic multi-organ syndrome, which may have onset during childhood. Vascular involvement is uncommon, with rarely reported coronary aneurysm formation. We present a case report of a teenager girl who developed recalcitrant life-threatening Behcet's vasculitis, involving both small and large venous and arterial systems including a giant coronary aneurysm.</p> <p>Case report</p> <p>De-identified data were collected retrospectively in case report format. Although our sixteen year old female with Behcet's vasculitis had resolution of many arterial aneurysms, she had persistent venous thrombosis of large vessels, as well as persistent, giant arterial aneurysms requiring intra-arterial coiling of a lumbar artery and coronary bypass grafting despite intensive immunosuppression including glucocorticoids, cyclophosphamide, infliximab, methotrexate, azathioprine and intravenous immunoglobulin.</p> <p>Conclusions</p> <p>Vascular manifestations may be seen in Behcet's syndrome, including asymptomatic coronary aneurysm, which may be refractory to immunosuppression and ultimately require surgical intervention. Increased awareness is essential for prompt diagnosis and management.</p

Generating MHV super-vertices in light-cone gauge

We constructe the $\mathcal{N}=1$ SYM lagrangian in light-cone gauge using chiral superfields instead of the standard vector superfield approach and derive the MHV lagrangian. The canonical transformations of the gauge field and gaugino fields are summarised by the transformation condition of chiral superfields. We show that $\mathcal{N}=1$ MHV super-vertices can be described by a formula similar to that of the $\mathcal{N}=4$ MHV super-amplitude. In the discussions we briefly remark on how to derive Nair's formula for $\mathcal{N}=4$ SYM theory directly from light-cone lagrangian.Comment: 25 pages, 7 figures, JHEP3 style; v2: references added, some typos corrected; Clarification on the condition used to remove one Grassmann variabl

Tree-Level Formalism

We review two novel techniques used to calculate tree-level scattering amplitudes efficiently: MHV diagrams, and on-shell recursion relations. For the MHV diagrams, we consider applications to tree-level amplitudes and focus in particular on the N=4 supersymmetric formulation. We also briefly describe the derivation of loop amplitudes using MHV diagrams. For the recursion relations, after presenting their general proof, we discuss several applications to massless theories with and without supersymmetry, to theories with massive particles, and to graviton amplitudes in General Relativity. This article is an invited review for a special issue of Journal of Physics A devoted to "Scattering Amplitudes in Gauge Theories".Comment: 40 pages, 8 figures, invited review for a special issue of Journal of Physics A devoted to "Scattering Amplitudes in Gauge Theories", R. Roiban(ed), M. Spradlin(ed), A. Volovich(ed); v2: minor corrections, references adde

Multigluon tree amplitudes with a pair of massive fermions

We consider the calculation of n-point multigluon tree amplitudes with a pair of massive fermions in QCD. We give the explicit transformation rules of this kind of massive fermion-pair amplitudes with respect to different reference momenta and check the correctness of them by SUSY Ward identities. Using these rules and onshell BCFW recursion relation, we calculate the analytic results of several n-point multigluon amplitudes.Comment: 15page

International differences in employee silence motives: Scale validation, prevalence, and relationships with culture characteristics across 33 Countries

Employee silence, the withholding of work-related ideas, questions, or concerns from someone who could effect change, has been proposed to hamper individual and collective learning as well as the detection of errors and unethical behaviors in many areas of the world. To facilitate cross-cultural research, we validated an instrument measuring four employee silence motives (i.e., silence based on fear, resignation, prosocial, and selfish motives) in 21 languages. Across 33 countries (N = 8,222) representing diverse cultural clusters, the instrument shows good psychometric properties (i.e., internal reliabilities, factor structure, measurement invariance). Results further revealed similarities and differences in the prevalence of silence motives between countries, but did not necessarily support cultural stereotypes. To explore the role of culture for silence, we examined relationships of silence motives with the societal practices cultural dimensions from the GLOBE Program. We found relationships between silence motives and power distance, institutional collectivism, and uncertainty avoidance. Overall, the findings suggest that relationships between silence and cultural dimensions are more complex than commonly assumed. We discuss the explanatory power of nations as (cultural) units of analysis, our social scientific approach, the predictive value of cultural dimensions, and opportunities to extend silence research geographically, methodologically, and conceptuallyinfo:eu-repo/semantics/publishedVersio