A
bstract
Searches for new resonances decaying into two photons in the ATLAS experiment at the CERN Large Hadron Collider are described. The analysis is based on proton-proton collision data ...corresponding to an integrated luminosity of 3.2 fb
−1
at
s
=
13
TeV recorded in 2015. Two searches are performed, one targeted at a spin-2 particle of mass larger than 500 GeV, using Randall-Sundrum graviton states as a benchmark model, and one optimized for a spin-0 particle of mass larger than 200 GeV. Varying both the mass and the decay width, the most significant deviation from the background-only hypothesis is observed at a diphoton invariant mass around 750 GeV with local significances of 3.8 and 3.9 standard deviations in the searches optimized for a spin-2 and spin-0 particle, respectively. The global significances are estimated to be 2.1 standard deviations for both analyses. The consistency between the data collected at 13 TeV and 8 TeV is also evaluated. Limits on the production cross section times branching ratio to two photons for the two resonance types are reported.
The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only ...three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90°E and 90°W, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.
A
bstract
This paper presents a measurement of the double-differential cross section for the Drell-Yan
Z/γ
∗
→
ℓ
+
ℓ
−
and photon-induced
γγ
→
ℓ
+
ℓ
−
processes where
ℓ
is an electron or muon. The ...measurement is performed for invariant masses of the lepton pairs,
m
ℓℓ
, between 116 GeV and 1500 GeV using a sample of 20
.
3 fb
−1
of
pp
collisions data at centre-of-mass energy of
s
=
8
TeV collected by the ATLAS detector at the LHC in 2012. The data are presented double differentially in invariant mass and absolute dilepton rapidity as well as in invariant mass and absolute pseudorapidity separation of the lepton pair. The single-differential cross section as a function of
m
ℓℓ
is also reported. The electron and muon channel measurements are combined and a total experimental precision of better than 1% is achieved at low
m
ℓℓ
. A comparison to next-to-next-to-leading order perturbative QCD predictions using several recent parton distribution functions and including next-to-leading order electroweak effects indicates the potential of the data to constrain parton distribution functions. In particular, a large impact of the data on the photon PDF is demonstrated.
Objectives
: The aim of the study was, by early identification of deleterious prognostic factors that are open to remediation, to be in a position to assign elderly patients to different mortality ...risk groups to improve management.
Design
: Prospective multicentre cohort.
Setting
: Nine French teaching hospitals.
Participants
: One thousand three hundred and six (1 306) patients aged 75 and over, hospitalised after having passed through Emergency Department (ED).
Measurements
: Patients were assessed using Comprehensive Geriatric Assessment (CGA) tools. A Cox survival analysis was performed to identify prognostic variables for six-week mortality. Receiver Operating Characteristics analysis was used to study the discriminant power of the model. A mortality risk score is proposed to define three risk groups for six-week mortality.
Results
: Crude mortality rate after a six-week follow-up was 10.6% (n=135). Prognostic factors identified were: malnutrition risk (HR=2.1; 95% CI: 1.1–3.8; p=.02), delirium (HR=1.7; 95% CI: 1.2-2.5; p=.006), and dependency: moderate dependency (HR=4.9; 95% CI: 1.5–16.5; p=.01) or severe dependency (HR=10.3; 95% CI: 3.2–33.1; p< .001). The discriminant power of the model was good: the c-statistic representing the area under the curve was 0.71 (95% IC: 0.67 – 0.75; p< .001). The six-week mortality rate increased significantly (p< .001) across the three risk groups: 1.1% (n=269; 95% CI=0.5–1.7) in the lowest risk group, 11.1% (n=854; 95% CI=9.4–12.9) in the intermediate risk group, and 22.4% (n=125; 95% CI=20.1–24.7) in the highest risk group.
Conclusions: A
simple score has been calculated (using only three variables from the CGA) and a practical schedule proposed to characterise patients according to the degree of mortality risk. Each of these three variables (malnutrition risk, delirium, and dependency) identified as independent prognostic factors can lead to a targeted therapeutic option to prevent early mortality.
Objectives
The aim of the study was to identify factors related to institutionalisation within one-year follow up of subjects aged 75 or over, hospitalised via the emergency department (ED).
Design
...Prospective multicentre cohort.
Setting
Nine French university teaching hospitals.
Participants
One thousand and forty seven (1 047) non institutionalised subjects aged 75 or over, hospitalised via ED. A sub group analysis was performed on the 894 subjects with a caregiver.
Measurements
Patients were assessed using Comprehensive Geriatric Assessment (CGA) tools. Cox survival analysis was performed to identify predictors of institutionalisation at one year.
Results
Within one year after hospital admission, 210 (20.1%) subjects were institutionalised For the overall study population, age >85 years (HR 1.6; 95% CI 1.1–2.1; p=0.005), inability to use the toilet (HR 1.6; 95%CI 1.1–2.4; p=0.007), balance disorders (HR 1.6; 95%CI 1.1–2.1; p=0.005) and presence of dementia syndrome (HR 1.9; 95%CI 1.4–2.6; p<0.001) proved to be independent predictors of institutionalisation; while a greater number of children was inversely linked to institutionalisation (HR 0.8; 95%CI 0.7–0.9; p<:0.001). Bathing was of borderline significance (p=.09). For subjects with a caregiver, initial caregiver burden was significantly linked to institutionalisation within one year, in addition to the predictors observed in the overall study population.
Conclusions
CGA performed at the beginning of hospitalisation in acute medical wards is useful to predict institutionalisation. Most of the predictors identified can lead to targeted therapeutic options with a view to preventing or delaying institution admission.
A
bstract
The angular distributions of Drell-Yan charged lepton pairs in the vicinity of the
Z
-boson mass peak probe the underlying QCD dynamics of
Z
-boson production. This paper presents a ...measurement of the complete set of angular coefficients
A
0−7
describing these distributions in the
Z
-boson Collins-Soper frame. The data analysed correspond to 20.3 fb
−1
of
pp
collisions at
s
=
8
TeV, collected by the ATLAS detector at the CERN LHC. The measurements are compared to the most precise fixed-order calculations currently available
O
α
s
2
and with theoretical predictions embedded in Monte Carlo generators. The measurements are precise enough to probe QCD corrections beyond the formal accuracy of these calculations and to provide discrimination between different parton-shower models. A significant deviation from the
O
α
s
2
predictions is observed for
A
0
−
A
2
. Evidence is found for non-zero
A
5,6,7
, consistent with expectations.
A
bstract
A search for pair production of vector-like quarks, both up-type (
T
) and down-type (
B
), as well as for four-top-quark production, is presented. The search is based on
pp
collisions at
s
...=
8
TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 20.3 fb
−1
. Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets. Dedicated analyses are performed targeting three cases: a
T
quark with significant branching ratio to a
W
boson and a
b
-quark
T
T
¯
→
Wb
+
X
, and both a
T
quark and a
B
quark with significant branching ratio to a Higgs boson and a third-generation quark (
T
T
¯
→
H
t
+
X
and
B
B
¯
→
H
b
+
X
respectively). No significant excess of events above the Standard Model expectation is observed, and 95% CL lower limits are derived on the masses of the vector-like
T
and
B
quarks under several branching ratio hypotheses assuming contributions from
T
→
Wb
,
Zt
,
Ht
and
B
→
Wt
,
Zb
,
Hb
decays. The 95% CL observed lower limits on the
T
quark mass range between 715 GeV and 950 GeV for all possible values of the branching ratios into the three decay modes, and are the most stringent constraints to date. Additionally, the most restrictive upper bounds on four-top-quark production are set in a number of new physics scenarios.
In the course of a high throughput screen to search for ligands of peroxisome proliferator activated receptor-γ (PPARγ), we identified GW9662 using a competition binding assay against the human ...ligand binding domain. GW9662 had nanomolar IC50 versus PPARγ and was 10- and 600-fold less potent in binding experiments using PPARα and PPARδ, respectively. Pretreatment of all three PPARs with GW9662 resulted in the irreversible loss of ligand binding as assessed by scintillation proximity assay. Incubation of PPAR with GW9662 resulted in a change in the absorbance spectra of the receptors consistent with covalent modification. Mass spectrometric analysis of the PPARγ ligand binding domain treated with GW9662 established Cys285 as the site of covalent modification. This cysteine is conserved among all three PPARs. In cell-based reporter assays, GW9662 was a potent and selective antagonist of full-length PPARγ. The functional activity of GW9662 as an antagonist of PPARγ was confirmed in an assay of adipocyte differentiation. GW9662 showed essentially no effect on transcription when tested using both full-length PPARδ and PPARα. Time-resolved fluorescence assays of ligand-modulated receptor heterodimerization, coactivator binding, and corepressor binding were consistent with the effects observed in the reporter gene assays. Control activators increased PPAR:RXR heterodimer formation and coactivator binding to both PPARγ and PPARδ. Corepressor binding was decreased. In the case of PPARα, GW9662 treatment did not significantly increase heterodimerization and coactivator binding or decrease corepressor binding. The experimental data indicate that GW9662 modification of each of the three PPARs results in different functional consequences. The selective and irreversible nature of GW9662 treatment, and the observation that activity is maintained in cell culture experiments, suggests that this compound may be a useful tool for elucidation of the role of PPARγ in biological processes.
Measurements of distributions of charged particles produced in proton–proton collisions with a centre-of-mass energy of 13 TeV are presented. The data were recorded by the ATLAS detector at the LHC ...and correspond to an integrated luminosity of 151
μ
b
-
1
. The particles are required to have a transverse momentum greater than 100 MeV and an absolute pseudorapidity less than 2.5. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on multiplicity are measured in events containing at least two charged particles satisfying the above kinematic criteria. The results are corrected for detector effects and compared to the predictions from several Monte Carlo event generators.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A
bstract
Charged-particle spectra obtained in Pb+Pb interactions at
s
N
N
=
2.76
TeV and
pp
interactions at
s
N
N
=
2.76
TeV with the ATLAS detector at the LHC are presented, using data with ...integrated luminosities of 0.15 nb
−1
and 4.2 pb
−1
, respectively, in a wide transverse momentum (0
.
5
< p
T
<
150 GeV) and pseudorapidity (|
η
|
<
2) range. For Pb+Pb collisions, the spectra are presented as a function of collision centrality, which is determined by the response of the forward calorimeters located on both sides of the interaction point. The nuclear modification factors
R
AA
and
R
CP
are presented in detail as a function of centrality,
p
T
and
η
. They show a distinct
p
T
-dependence with a pronounced minimum at about 7 GeV. Above 60 GeV,
R
AA
is consistent with a plateau at a centrality-dependent value, within the uncertainties. The value is 0
.
55 ± 0
.
01(stat
.
) ± 0
.
04(syst
.
) in the most central collisions. The
R
AA
distribution is consistent with flat |
η
| dependence over the whole transverse momentum range in all centrality classes.
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