A search for the dimuon decay of the Standard Model (SM) Higgs boson is performed using data corresponding to an integrated luminosity of 139 fb−1 collected with the ATLAS detector in Run 2 pp ...collisions at s=13 TeV at the Large Hadron Collider. The observed (expected) significance over the background-only hypothesis for a Higgs boson with a mass of 125.09 GeV is 2.0σ (1.7σ). The observed upper limit on the cross section times branching ratio for pp→H→μμ is 2.2 times the SM prediction at 95% confidence level, while the expected limit on a H→μμ signal assuming the absence (presence) of a SM signal is 1.1 (2.0). The best-fit value of the signal strength parameter, defined as the ratio of the observed signal yield to the one expected in the SM, is μ=1.2±0.6.
This study evaluated the role of progesterone (P4) and medroxyprogesterone acetate (MAP) on the molecular status of immature cumulus–oocyte complexes (COCs) and the implications for oocyte quality in ...sheep. The number of viable COCs per ewe and the rate of COCs screened for developmental competence by brilliant cresyl blue positive (BCB+) were similar (P > 0.05), respectively, across treatments (P4: 7.7 ± 0.7 and 4.7 ± 1.2; MAP: 5.7 ± 1.0 and 3.5 ± 2.3; and control: 5.7 ± 1.1 and 3.6 ± 2.4). The COCs' gene expression was altered by exogenous progestogens compared with the control group: markers of steroidogenic pathway (FSH receptor FSHr, LH receptor LHr, and estradiol receptor α) and of quality (zygote arrest 1, growth differentiation factor 9, and B-cell lymphoma 2) were in abundance in P4 (P < 0.05). In addition, reelin protein (RELN) was downregulated, and Bcl-2 was upregulated in MAP (P < 0.05). In the P4 vs MAP comparison, FSHr, LHr, and RELN genes were upregulated (P < 0.05) in the P4 group. In conclusion, P4 and MAP promoted dissimilar effects on transcriptome profiling of immature BCB-selected COCs, possibly due to the differences in the chemical structure of progestogens and concentrations of serum P4. Exogenous P4 impacted positively on the profile of genes related to oocyte quality.
•Exogenous progesterone (P4) and medroxyprogesterone acetate (MAP) cause dissimilar effects on gene expression in fully grown cumulus–oocyte complex (COCs).•RELN gene is downregulated in brilliant cresyl blue–positive (BCB+) COCs from MAP treatment compared with the nontreated and P4-treated ewes.•Zygote arrest 1, growth differentiation factor 9, LH receptor, FSH receptor, and estradiol receptor were upregulated in BCB+ COC treated with exogenous P4 compared with nontreated ewes.•Higher P4 serum concentrations on oocyte recovery day was found in ewes treated with exogenous P4 than nontreated or MAP-treated ewes.
Electron and photon triggers covering transverse energies from 5
GeV
to several
TeV
are essential for the ATLAS experiment to record signals for a wide variety of physics: from Standard Model ...processes to searches for new phenomena in both proton–proton and heavy-ion collisions. To cope with a fourfold increase of peak LHC luminosity from 2015 to 2018 (Run 2), to
2.1
×
10
34
cm
-
2
s
-
1
, and a similar increase in the number of interactions per beam-crossing to about 60, trigger algorithms and selections were optimised to control the rates while retaining a high efficiency for physics analyses. For proton–proton collisions, the single-electron trigger efficiency relative to a single-electron offline selection is at least 75% for an offline electron of 31
GeV
, and rises to 96% at 60
GeV
; the trigger efficiency of a 25
GeV
leg of the primary diphoton trigger relative to a tight offline photon selection is more than 96% for an offline photon of 30
GeV
. For heavy-ion collisions, the primary electron and photon trigger efficiencies relative to the corresponding standard offline selections are at least 84% and 95%, respectively, at 5
GeV
above the corresponding trigger threshold.
This study evaluated the effect of roughage:concentrate (R:C) ratio associated with a variable particle size of physically effective neutral detergent fibre (peNDF8) in the forage (Tifton-85 hay) on ...the performance, carcass traits and meat quality of lambs. Seventy-two 4-month-old, non-castrated Santa Ines male lambs (23.5 ± 2.32 kg BW) were distributed in a completely randomized design, in a 2 × 2 factorial arrangement two peNDF8 hay particle sizes (13 and 6 mm) and two R:C ratios (700:300 and 500:500 g/kg DM total). DMI, DM, NFC and TDN digestibility's, N-intake and N-faecal excretion were affected by the R:C ratio (P < 0.05). However, the N-retained was not affected by the studied variables (P > 0.05). It was observed an interaction (P < 0.05) between the peNDF8 and R:C ratios for final BW, average daily gain (ADG), colour parameters and pH 24 h. The lower roughage ratio provided greater (P < 0.05) concentrations of C14:1, C16:1–cis9, C18:1–cis9, ΣMUFA, Σn–6:Σn–3 and hypocholesterolemic/hypercholesterolemic index, enzymatic activity Δ9desaturase-C16 and -C18. Lambs fed a lower roughage diet had improved performance and feed efficiency, however, presented reduced polyunsaturated fatty acids (PUFA) concentrations in the meat, especially Σn–3 family. Higher roughage diet and larger peNDF8 particle size improved the concentrations of PUFA while decreased Σn–6:Σn–3 ratio in meat. Larger peNDF8 particle size associated with higher roughage proportion, have reduced animal performance however, it increased protein concentration, a* and C* colour parameter without affecting fatty acids profile of Longissimus lumborum muscle.
The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the ...searches performed by the ATLAS and CMS Collaborations with proton-proton collision datasets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018. These correspond to integrated luminosities of around 140 fb^{-1} for each experiment, at a center-of-mass energy of 13 TeV. The measured signal yield is 2.2±0.7 times the standard model prediction, and agrees with the theoretical expectation within 1.9 standard deviations.
Heavy-flavour hadron production provides information about the transport properties and microscopic structure of the quark–gluon plasma created in ultra-relativistic heavy-ion collisions. A ...measurement of the muons from semileptonic decays of charm and bottom hadrons produced in Pb+Pb and pp collisions at a nucleon–nucleon centre-of-mass energy of 5.02 TeV with the ATLAS detector at the Large Hadron Collider is presented. The Pb+Pb data were collected in 2015 and 2018 with sampled integrated luminosities of 208μb−1 and 38μb−1, respectively, and pp data with a sampled integrated luminosity of 1.17pb−1 were collected in 2017. Muons from heavy-flavour semileptonic decays are separated from the light-flavour hadronic background using the momentum imbalance between the inner detector and muon spectrometer measurements, and muons originating from charm and bottom decays are further separated via the muon track's transverse impact parameter. Differential yields in Pb+Pb collisions and differential cross sections in pp collisions for such muons are measured as a function of muon transverse momentum from 4 GeV to 30 GeV in the absolute pseudorapidity interval |η|<2. Nuclear modification factors for charm and bottom muons are presented as a function of muon transverse momentum in intervals of Pb+Pb collision centrality. The bottom muon results are the most precise measurement of b quark nuclear modification at low transverse momentum where reconstruction of B hadrons is challenging. The measured nuclear modification factors quantify a significant suppression of the yields of muons from decays of charm and bottom hadrons, with stronger effects for muons from charm hadron decays.
This paper describes a study of techniques for identifying Higgs bosons at high transverse momenta decaying into bottom-quark pairs,
H
→
b
b
¯
, for proton–proton collision data collected by the ...ATLAS detector at the Large Hadron Collider at a centre-of-mass energy
s
=
13
TeV
. These decays are reconstructed from calorimeter jets found with the anti-
k
t
R
=
1.0
jet algorithm. To tag Higgs bosons, a combination of requirements is used:
b
-tagging of
R
=
0.2
track-jets matched to the large-
R
calorimeter jet, and requirements on the jet mass and other jet substructure variables. The Higgs boson tagging efficiency and corresponding multijet and hadronic top-quark background rejections are evaluated using Monte Carlo simulation. Several benchmark tagging selections are defined for different signal efficiency targets. The modelling of the relevant input distributions used to tag Higgs bosons is studied in 36 fb
-
1
of data collected in 2015 and 2016 using
g
→
b
b
¯
and
Z
(
→
b
b
¯
)
γ
event selections in data. Both processes are found to be well modelled within the statistical and systematic uncertainties.
Semi-visible jets, with a significant contribution to the event's missing transverse momentum, can arise in strongly interacting dark sectors. This results in an event topology where one of the jets ...can be aligned with the direction of the missing transverse momentum. The first search for semi-visible jets produced via a t-channel mediator exchange is presented. The analysis uses proton-proton collisions with an integrated luminosity of 139 fb−1 and a centre-of-mass energy of 13 TeV, collected with the ATLAS detector during the Run 2 of the LHC. No excess over Standard Model predictions is observed. Assuming a coupling strength of unity between the mediator, a Standard Model quark and a dark quark, mediator masses up to 2.7 TeV are excluded at the 95% confidence level. Upper limits on the coupling strength are also derived.
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