1,721,057 research outputs found
Vector-like tops from first generation quarks: the role of width and coupling chiralities in same-charge production at the LHC
No full textIn this paper, we tension the scope of the q\bar q, gg\to T \bar T production process against that of the same-charge uu\to TT one in searching for Vector-Like Quarks (VLQs) with electromagnetic charge +2/3 at the Large Hadron Collider (LHC). The study is conducted by considering a simplified model in which such new states couple exclusively to Standard Model quarks of the first generation through W^\pm, Z and H currents. We consider both left-handed or right-handed dominant chiralities, representative of SU(2)_L singlets or doublets, and the total widths are allowed to reach large values relatively to the VLQ masses. By deconstructing the signal into all its components, we assess current and projected constraints, emphasize the role of interference terms and isolate peculiar features which can be used for dedicated searches at the LHC or future colliders
Vector-like quarks coupling discrimination at the LHC and future hadron colliders
Full text linkAbstract The existence of new coloured states with spin one-half, i.e. extra-quarks, is a striking prediction of various classes of new physics models. Should one of these states be discovered during the 13 TeV runs of the LHC or at future high energy hadron colliders, understanding its properties will be crucial in order to shed light on the underlying model structure. Depending on the extra-quarks quantum number under SU(2) L , their coupling to Standard Model quarks and bosons have either a dominant left- or right-handed chiral component. By exploiting the polarisation properties of the top quarks arising from the decay of pair-produced extra quarks, we show how it is possible to discriminate among the two hypothesis in the whole discovery range currently accessible at the LHC, thus effectively narrowing down the possible interpretations of a discovered state in terms of new physics scenarios. Moreover, we estimate the discovery and discrimination power of future prototype hadron colliders with centre of mass energies of 33 and 100 TeV
Azione antimicrobica di alcuni flavonoidi nei confronti di batteri e funghi: rapporti struttura-attività
No full textAntimicrobial and antimycotic activity of crude extracts and pure compounds from Astragalus verrucosus
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Valutazione dell'attività antimicrobica, in vitro, di quercetina e naringenina e dei corrispondenti diglicosidi
No full textThree anthrones from Rubus ulmifolius
No full textFrom the aerial parts of Rubus ulmifolius Schott three new anthrones, rubanthrone A, B and C, have been isolated. Their structures were established by spectral procedures including 1D and 2D NMR techniques and chemical derivatization. Rubanthrone A showed antimicrobial activity against Staphylococcus aureus at 4.5 mg/ml
Composition and antimicrobial properties of essential oils of four Mediterranean Lamiaceae
No full textEssential oils from Satureja montana L., Rosmarinus officinalis L., Thymus vulgaris L., and Calamintha nepeta (L.) Savi, were chemically analysed and their antimicrobial and fungicide activities evaluated on the basis of their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). All four oils have a biotoxic effect, the most active being those from Calamintha and Thymu
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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