Measurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with the ATLAS detector at √s = 13 TeV

Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented using 139 fb−1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at s = 13 TeV is measured to be σ = 1.267 ± 0.005 ± 0.053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4.2%. The cross-section is measured differentially as a function of variables characterising the tt¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators OtG and Otq(8), where the limits on the latter are the most stringent to date. [Figure not available: see fulltext.]

Direct constraint on the Higgs–charm coupling from a search for Higgs boson decays into charm quarks with the ATLAS detector

A search for the Higgs boson decaying into a pair of charm quarks is presented. The analysis uses proton–proton collisions to target the production of a Higgs boson in association with a leptonically decaying W or Z boson. The dataset delivered by the LHC at a centre-of-mass energy of and recorded by the ATLAS detector corresponds to an integrated luminosity of 139 fb−1. Flavour-tagging algorithms are used to identify jets originating from the hadronisation of charm quarks. The analysis method is validated with the simultaneous measurement of WW, WZ and ZZ production, with observed (expected) significances of 2.6 (2.2) standard deviations above the background-only prediction for the (W/Z)Z(→cc¯) process and 3.8 (4.6) standard deviations for the (W/Z)W(→cq) process. The (W/Z)H(→cc¯) search yields an observed (expected) upper limit of 26 (31) times the predicted Standard Model cross-section times branching fraction for a Higgs boson with a mass of , corresponding to an observed (expected) constraint on the charm Yukawa coupling modifier |κc|<8.5 (12.4), at the 95% confidence level. A combination with the ATLAS (W/Z)H,H→bb¯ analysis is performed, allowing the ratio κc/κb to be constrained to less than 4.5 at the 95% confidence level, smaller than the ratio of the b- and c-quark masses, and therefore determines the Higgs-charm coupling to be weaker than the Higgs-bottom coupling at the 95% confidence level

Infection, genetic variation analysis and biology study of biocontrol agent Isturgia disputaria (Guenees) on Acia nilotica in Pakistan.

In Pakistan, Trees of Acacia nilotica are extremely valuable sources of fuel, small timber and have important pharmaceutical and medicinal value. But on the other hands, in Australia, Acacia nilotica subsp. indica is the most serious weed of national significance because of its potential of spread, invasiveness, economic and environmental impacts. Different strategies including leaf feeding insects as biological control agents are being used against such wild plant species. Surveys for leaf feeding insects on Acacia nilotica during 2018-2019 revealed the enhanced infestation (15%-38%) with the presence of a potential biological control agent, Isturgia disputaria in various districts of Punjab, Pakistan. For proper molecular identification, DNA was extracted from collected samples and polymerase chain reaction (PCR) was performed to amplify a 710bp fragment of the mitochondrial COI gene. The amplified PCR products were sequenced and phylogenetic examination and genetic evolutionary divergence (GD) showed that studied species of I. disputaria exhibited 99-100% homology (NCBI Acc. No MK301226) with other submitted sequences of I. disputaria (KX861182.1, KF147289.1) on NCBI GenBank database. Further, feeding and development potential of this species in no-choice tests on foliage of A. nilotica spp. indicated a good larval feeding and developmental capability for prickly acacia, A. nilotica indica and A. tomentosa indicating future threat for acacia forest in Pakistan. The larvae of I. disputaria completed their devel­opment life cycle 80-100% more successfully on A. nilotica subsp. indica and A. nilotica tomentosa than the larval development tested on other related species of Acacia existed in Pakistan. This is the first report of infestation, identification and biological features of potential biological control agent I. disputaria in Pakistan. This insect can also be reared to control wild species but, its increasing infestation on A. nilotica can be problematic for billion tree Project initiated by Government of Pakista

Phytoplasma diseases of medicinal crops

Phytoplasma diseases of medicinal plants occur worldwide and are of great concern. So far 19 different phytoplasma ribosomal groups encompassing various subgroups have been reported. The subgroup 16SrI-B phytoplasmas are the prevalent agents mainly detected in Europe, North America and Asia. Phytoplasma diseases of medicinal plants severely reduce yield and quality of crops along with the longevity of the plants. Changes in the composition of secondary metabolites are induced, while the levels of valuable phytochemicals are greatly affected. In contrast, an accumulation of pharmaceutically important compounds such as vinblastine and vincristine is reported in periwinkle upon phytoplasma infections. Important phytoplasma diseases of several medicinal plants with special reference to their impact on active biological constituents and secondary metabolites are reviewed. General information on geographic distribution, diagnostics, genetic diversity, natural transmission and management aspects of phytoplasmas infecting medicinal plants are also discussed

Anomaly detection search for new resonances decaying into a Higgs boson and a generic new particle X in hadronic final states using s=13 TeV pp collisions with the ATLAS detector

A search is presented for a heavy resonance Y decaying into a Standard Model Higgs boson H and a new particle X in a fully hadronic final state. The full Large Hadron Collider run 2 dataset of proton-proton collisions at..