Effects of starch sources and processing on nutrient digestibility and ruminal parameters of lactating cows

Cinco vacas holandesas pluríparas, com cânulas no rúmen e no duodeno, foram distribuídas em delineamento de quadrado latino 5 x 5. As vacas foram submetidas a cinco rações experimentais contendo 40% de cana-de-açúcar, 60% de concentrado e cerca de 30% de amido. As rações diferiram quanto ao processamento ou à fonte principal do amido utilizado: milho grosseiramente moído, milho finamente moído, milho floculado a 310g/l, milho floculado a 360g/l ou raspa de mandioca. Não houve diferença (P>0,05) no consumo de matéria seca entre os tratamentos. A digestibilidade ruminal do amido foi maior na ração que continha raspa de mandioca. As digestibilidades ruminal da fibra em detergente neutro e da fibra em detergente ácido não diferiram entre os tratamentos. Os dados médios de pH ruminal se mantiveram acima de 6,0, exceto às 2 e às 4h após a alimentação com a dieta que continha raspa de mandioca. Não houve efeito significativo dos tratamentos sobre a concentração de ácidos graxos voláteis totais. O processo de floculação promoveu aumento da digestibilidade do amido do milho, em relação à moagem de forma grosseira. A digestibilidade ruminal do amido presente na raspa de mandioca foi maior do que a do milho, independentemente da forma de processamento utilizada.Five multiparous lactating Holsteins cows, cannulated in the rumen and proximal duodenum, were used in a 5 x 5 latin square. Cows were fed a 40:60 forage: concentrate diet (40% fresh sugar cane and 60% concentrate). Diets were formulated to have 30% of starch and treatments were starch sources and ration processing forms: cracked corn, finely ground corn, flaked corn at 310g/l, flaked corn at 360g/l, or cassava scrapings. No difference (P>0.05) was observed among treatments for dry matter intake. Starch ruminal digestibility was higher for cassava scrapings treatment. NDF and ADF digestibility were similar among treatments. Average values of ruminal pH were above 6, except at 2 and 4h after feeding the cassava diet. There was no effect of treatment on concentrations of total volatile fatty acids. The flocculation process increased corn starch digestibility. Ruminal degradability of the cassava scrapings starch was higher than corn, without effect of processing form

Search for heavy Majorana or Dirac neutrinos and right-handed W gauge bosons in final states with charged leptons and jets in pp collisions at √s = 13 TeV with the ATLAS detector

A search for heavy right-handed Majorana or Dirac neutrinos NR and heavy right-handed gauge bosons WR is performed in events with energetic electrons or muons, with the same or opposite electric charge, and energetic jets. The search is carried out separately for topologies of clearly separated final-state products (“resolved” channel) and topologies with boosted final states with hadronic and/or leptonic products partially overlapping and reconstructed as a large-radius jet (“boosted” channel). The events are selected from pp collision data at the LHC with an integrated luminosity of 139 fb−1 collected by the ATLAS detector at √s = 13 TeV. No significant deviations from the Standard Model predictions are observed. The results are interpreted within the theoretical framework of a left-right symmetric model, and lower limits are set on masses in the heavy righthanded WR boson and NR plane. The excluded region extends to about m(WR) = 6.4 TeV for both Majorana and Dirac NR neutrinos at m(NR) < 1 TeV. NR with masses of less than 3.5 (3.6) TeV are excluded in the electron (muon) channel at m(WR) = 4.8 TeV for the Majorana neutrinos, and limits of m(NR) up to 3.6 TeV for m(WR) = 5.2 (5.0) TeV in the electron (muon) channel are set for the Dirac neutrinos. These constitute the most stringent exclusion limits to date for the model considered

Observation of quantum entanglement with top quarks at the ATLAS detector

Entanglement is a key feature of quantum mechanics with applications in fields such as metrology, cryptography, quantum information and quantum computation. It has been observed in a wide variety of systems and length scales, ranging from the microscopic to the macroscopic. However, entanglement remains largely unexplored at the highest accessible energy scales. Here we report the highest-energy observation of entanglement, in top–antitop quark events produced at the Large Hadron Collider, using a proton–proton collision dataset with a centre-of-mass energy of √s = 13 TeV and an integrated luminosity of 140 inverse femtobarns (fb)−1 recorded with the ATLAS experiment. Spin entanglement is detected from the measurement of a single observable D, inferred from the angle between the charged leptons in their parent top- and antitop-quark rest frames. The observable is measured in a narrow interval around the top–antitop quark production threshold, at which the entanglement detection is expected to be significant. It is reported in a fiducial phase space defined with stable particles to minimize the uncertainties that stem from the limitations of the Monte Carlo event generators and the parton shower model in modelling top-quark pair production. The entanglement marker is measured to be D = −0.537 ± 0.002 (stat.) ± 0.019 (syst.) for 340 GeV < mtt < 380 GeV. The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement so far

The performance of missing transverse momentum reconstruction and its significance with the ATLAS detector using 140 fb-1 of √s = 13 TeV TeV pp collisions

Abstract This paper presents the reconstruction of missing transverse momentum ( $$p_{\text {T}}^{\text {miss}}$$ p T miss ) in proton–proton collisions, at a center-of-mass energy of 13 TeV. This is a challenging task involving many detector inputs, combining fully calibrated electrons, muons, photons, hadronically decaying $$\tau$$ τ -leptons, hadronic jets, and soft activity from remaining tracks. Possible double counting of momentum is avoided by applying a signal ambiguity resolution procedure which rejects detector inputs that have already been used. Several $$p_{\text {T}}^{\text {miss}}$$ p T miss ‘working points’ are defined with varying stringency of selections, the tightest improving the resolution at high pile-up by up to 39% compared to the loosest. The $$p_{\text {T}}^{\text {miss}}$$ p T miss performance is evaluated using data and Monte Carlo simulation, with an emphasis on understanding the impact of pile-up, primarily using events consistent with leptonic Z decays. The studies use $$140~\text {fb}^{-1}$$ 140 fb - 1 of data, collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. The results demonstrate that $$p_{\text {T}}^{\text {miss}}$$ p T miss reconstruction, and its associated significance, are well understood and reliably modelled by simulation. Finally, the systematic uncertainties on the soft $$p_{\text {T}}^{\text {miss}}$$ p T miss component are calculated. After various improvements the scale and resolution uncertainties are reduced by up to $$76\%$$ 76 % and $$51\%$$ 51 % , respectively, compared to the previous calculation at a lower luminosity

Reconstruction and identification of pairs of collimated τ-leptons decaying hadronically using sqrt{s}=13 TeV pp collision data with the ATLAS detector

This paper describes an algorithm for reconstructing and identifying a highly collimated hadronically decaying τ -lepton pair with low transverse momentum. When two τ -leptons are highly collimated, their visible decay products might overlap, degrading the reconstruction performance for each of the τ -leptons. A dedicated treatment attempting to tag the τ -lepton pair as a single object is required. The reconstruction algorithm is based on a large radius jet and its associated two leading subjets, and the identification uses a boosted decision tree to discriminate between signatures from τ +τ − systems and those arising from QCD jets. The efficiency of the identification algorithm is measured in Zγ events using proton–proton collision data at √s = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018, corresponding to an integrated luminosity of 139 fb−1. The resulting data-to-simulation scale factors are close to unity with uncertainties ranging from 26 to 37%