Moulting phenology of the harbour seal in south-west Ireland

Studies on the phenology of harbour seal moult have been carried out in the Atlantic and Pacific, however there has been no research into this process in the Republic of Ireland, at the southern edge of the species range in the north-east Atlantic. Population estimates of harbour seals are derived by counts primarily during the moulting seasons. In the absence of information on the moult phenology planning the optimal timing of such surveys is impossible. Furthermore, changes in moult phenology may reflect changes in resource availability or competition, or demographic changes. The phenology of the harbour seal moult was investigated in south-west Ireland in this study. Timing of the moult differed among all cohorts, yearlings began moulting first followed by adult females and finally adult males. The number of seals hauled out was generally positively related to the proportion of seals in active moult. The timing of the moult period was different to other parts of the species' range and should be considered in determining optimal timing of future surveys for assessing populations abundance and trends in Ireland

Prevalence and co-infection of Toxoplasma gondii and Neospora caninum in Apodemus sylvaticus in an area relatively free of cats

The protozoan parasite Toxoplasma gondii is prevalent worldwide and can infect a remarkably wide range of hosts despite felids being the only definitive host. As cats play a major role in transmission to secondary mammalian hosts, the interaction between cats and these hosts should be a major factor determining final prevalence in the secondary host. This study investigates the prevalence of T. gondii in a natural population of Apodemus sylvaticus collected from an area with low cat density (<2·5 cats/km2). A surprisingly high prevalence of 40·78% (95% CI: 34·07%–47·79%) was observed despite this. A comparable level of prevalence was observed in a previously published study using the same approaches where a prevalence of 59% (95% CI: 50·13%–67·87%) was observed in a natural population of Mus domesticus from an area with high cat density (>500 cats/km2). Detection of infected foetuses frompregnant dams in both populations suggests that congenital transmission may enable persistence of infection in the absence of cats. The prevalences of the related parasite, Neospora caninum were found to be low in both populations (A. sylvaticus: 3·39% (95% CI: 0·12%–6·66%); M. domesticus: 3·08% (95% CI: 0·11%–6·05%)). These results suggest that cat density may have a lower than expected effect on final prevalence in these ecosystems

Search for a heavy bottom-like quark in pp collisions at √s = 7 TeV

A search for pair-produced bottom-like quarks in pp collisions at √s = 7 TeV is conducted with the CMS experiment at the LHC. The decay b′→tW is considered in this search. The b'b'→ tW^-tW^+ process can be identified by the distinctive signature of trileptons and same-sign dileptons. With a data sample corresponding to an integrated luminosity of 34 pb^(−1), no excess above the standard model background predictions is observed and a b′ quark with a mass between 255 and 361 GeV/c^2 is excluded at the 95% confidence level

Jet production rates in association with W and Z bosons in pp collisions at √s = 7 TeV

Measurements of jet production rates in association with W and Z bosons for jet transverse momenta above 30 GeV are reported, using a sample of proton-proton collision events recorded by CMS at √s = 7TeV, corresponding to an integrated luminosity of 36 pb^(-1). The study includes the measurement of the normalized inclusive rates of jets σ(V+ ≥n jets)/σ(V), where V represents either a W or a Z. In addition, the ratio of W to Z cross sections and the W charge asymmetry as a function of the number of associated jets are measured. A test of scaling at √s = 7TeV is also presented. The measurements provide a stringent test of perturbative-QCD calculations and are sensitive to the possible presence of new physics. The results are in agreement with the predictions of a simulation that uses explicit matrix element calculations for nal states with jets

Measurement of the tt production cross section in pp collisions at √s = 7 TeV in dilepton final states containing a τ

The top quark pair production cross section is measured in dilepton events with one electron or muon, and one hadronically decaying τ lepton from the decay tt →(ℓν_ℓ)(τ_hν_τ)bb, (ℓ=e,μ). The data sample corresponds to an integrated luminosity of 2.0  fb^(-1) for the electron channel and 2.2  fb^(-1) for the muon channel, collected by the CMS detector at the LHC. This is the first measurement of the tt cross section explicitly including τ leptons in proton-proton collisions at √s=7  TeV. The measured value σ_(tt) =143±14(stat)±22(syst)±3(lumi)  pb is consistent with the standard model predictions

Search for quark compositeness in dijet angular distributions from pp collisions at √s = 7 TeV

A search for quark compositeness using dijet angular distributions from pp collisions at √s = 7 TeV is presented. The search has been carried out using a data sample corresponding to an integrated luminosity of 2.2 fb^(−1), recorded by the CMS experiment at the LHC. Normalized dijet angular distributions have been measured for dijet invariant masses from 0.4 TeV to above 3 TeV and compared with a variety of contact interaction models, including those which take into account the effects of next-to-leading-order QCD corrections. The data are found to be in agreement with the predictions of perturbative QCD, and lower limits are obtained on the contact interaction scale, ranging from 7.5 up to 14.5 TeV at 95 % confidence level

Combined collider constraints on neutralinos and charginos

Searches for supersymmetric electroweakinos have entered a crucial phase, as the integrated luminosity of the Large Hadron Collider is now high enough to compensate for their weak production cross-sections. Working in a framework where the neutralinos and charginos are the only light sparticles in the Minimal Supersymmetric Standard Model, we use gambit to perform a detailed likelihood analysis of the electroweakino sector. We focus on the impacts of recent ATLAS and CMS searches with 36 fb$^{-1}$ of 13 TeV proton-proton collision data. We also include constraints from LEP and invisible decays of the $Z$ and Higgs bosons. Under the background-only hypothesis, we show that current LHC searches do not robustly exclude any range of neutralino or chargino masses. However, a pattern of excesses in several LHC analyses points towards a possible signal, with neutralino masses of $(m_{\tilde{\chi}_1^0}, m_{\tilde{\chi}_2^0}, m_{\tilde{\chi}_3^0}, m_{\tilde{\chi}_4^0})$ = (8-155, 103-260, 130-473, 219-502) GeV and chargino masses of $(m_{\tilde{\chi}_1^{\pm}}, m_{\tilde{\chi}_2^{\pm}})$ = (104-259, 224-507) GeV at the 95% confidence level. The lightest neutralino is mostly bino, with a possible modest Higgsino or wino component. We find that this excess has a combined local significance of $3.3\sigma$, subject to a number of cautions. If one includes LHC searches for charginos and neutralinos conducted with 8 TeV proton-proton collision data, the local significance is lowered to 2.9$\sigma$. We briefly consider the implications for dark matter, finding that the correct relic density can be obtained through the Higgs-funnel and $Z$-funnel mechanisms, even assuming that all other sparticles are decoupled. All samples, gambit input files and best-fit models from this study are available on Zenodo.Comment: 38 pages, 16 figures, v3 is the version accepted by EPJ

Inclusive b-jet production in pp collisions at √s = 7 TeV

The inclusive b-jet production cross section in pp collisions at a center-of mass energy of 7 TeV is measured using data collected by the CMS experiment at the LHC. The cross section is presented as a function of the jet transverse momentum in the range 18 < p_T  < 200 GeV for several rapidity intervals. The results are also given as the ratio of the b-jet production cross section to the inclusive jet production cross section. The measurement is performed with two different analyses, which differ in their trigger selection and b-jet identification: a jet analysis that selects events with a b jet using a sample corresponding to an integrated luminosity of 34 pb^(−1), and a muon analysis requiring a b jet with a muon based on an integrated luminosity of 3 pb^(−1). In both approaches the b jets are identified by requiring a secondary vertex. The results from the two methods are in agreement with each other and with next-to-leading order calculations, as well as with predictions based on the pythia event generator

Measurement of the charge asymmetry in top-quark pair production in proton–proton collisions at √s = 7 TeV

The difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured in pp collisions at the LHC with the CMS experiment. The data sample corresponds to an integrated luminosity of 1.09 fb^(−1) at a centre-of-mass energy of 7 TeV. Top-quark pairs are selected in the final state with an electron or muon and four or more jets. At least one jet is identified as originating from b-quark hadronization. The charge asymmetry is measured in two variables, one based on the pseudorapidities (η) of the top quarks and the other on their rapidities (y). The results A^η_C = −0.017 ± 0.032 (stat.) ^(+0.025)_(−0.036) (syst.) and A^y_C = −0.013 ± 0.028 (stat.) ^(+0.029)_(−0.031) (syst.) are consistent within uncertainties with the standard-model predictions