We present a measurement of forward-backward asymmetry in top quark-antiquark production in proton-antiproton collisions in the final state containing a lepton and at least four jets. Using a dataset ...corresponding to an integrated luminosity of 5.4 fb-1, collected by the D0 experiment at the Fermilab Tevatron Collider, we measure the t{bar t} forward-backward asymmetry to be (9.2 ± 3.7)% at the reconstruction level. When corrected for detector acceptance and resolution, the asymmetry is found to be (19.6 ± 6.5)%. We also measure a corrected asymmetry based on the lepton from a top quark decay, found to be (15.2 ± 4.0)%. The results are compared to predictions based on the next-to-leading-order QCD generator mc@nlo. The sensitivity of the measured and predicted asymmetries to the modeling of gluon radiation is discussed.
We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb(-1) of p (p) over bar collisions recorded with the D0 detector at a center-of-mass energy root s = 1.96 TeV at the Fermilab ...Tevatron collider. From A, we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.00957 +/- 0.00251 (stat) +/- 0.00146 (syst). This result differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(0.6)(+0.5)) x 10(-4) and provides first evidence of anomalous CP violation in the mixing of neutral B mesons.
We use higher-order quantum chromodynamics calculations to extract the mass of the top quark from the tt¯ cross section measured in the lepton + jets channel in pp¯ collisions at s=1.96 TeV using 5.3 ...fb−1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. The extracted top quark pole mass and MS¯ mass are compared to the current Tevatron average top quark mass obtained from direct measurements.
To evaluate the incidence rate of Chronic Kidney Disease (CKD) stage 3-5 (persistent decreased kidney function under 60 mL/min per 1.73 m2) among patients with type 2 diabetes over five years, to ...identify the risk factors associated with CKD, and develop a risk table to predict five-year CKD stage 3-5 risk stratification for clinical use.
The MADIABETES Study is a prospective cohort study of 3,443 outpatients with type 2 diabetes mellitus, sampled from 56 primary health care centers (131 general practitioners) in Madrid (Spain).
The cumulative incidence of CKD stage 3-5 at five-years was 10.23% (95% CI = 9.12-11.44) and the incidence density was 2.07 (95% CI = 1.83-2.33) cases per 1,000 patient-months or 2.48 (95% CI = 2.19-2.79) cases per 100 patient-years. The highest hazard ratio (HR) for developing CKD stage 3-5 was albuminuria ≥ 300 mg/g (HR = 4.57; 95% CI= 2.46-8.48). Furthermore, other variables with a high HR were age over 74 years (HR = 3.20; 95% CI = 2.13-4.81), a history of Hypertension (HR = 2.02; 95% CI = 1.42-2.89), Myocardial Infarction (HR= 1.72; 95% IC= 1.25-2.37), Dyslipidemia (HR = 1.68; 95% CI 1.30-2.17), duration of diabetes mellitus ≥ 10 years (HR = 1.46; 95% CI = 1.14-1.88) and Systolic Blood Pressure >149 mmHg (HR = 1.52; 95% CI = 1.02-2.24).
After a five-year follow-up, the cumulative incidence of CKD is concordant with rates described in Spain and other countries. Albuminuria ≥ 300 mg/g and age over 74 years were the risk factors more strongly associated with developing CKD (Stage 3-5). Blood Pressure, lipid and albuminuria control could reduce CKD incidence of CKD in patients with T2DM.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report observation of the electroweak production of single top quarks in ppover collisions at sqrts=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron ...Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(ppover --> tb + X, tqb + X) = 3.94 + or - 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10(-7), corresponding to a 5.0 standard deviation significance for the observation.
We present a measurement of the tt¯ production cross section σtt¯ in pp¯ collisions at s=1.96 TeV using 5.4 fb−1 of integrated luminosity collected with the D0 detector. We consider final states with ...at least two jets and two leptons (ee, eμ, μμ), and events with one jet for the eμ final state as well. The measured cross section is σtt¯=7.36−0.79+0.90(stat+syst) pb. This result combined with the cross section measurement in the lepton+jets final state yields σtt¯=7.56−0.56+0.63(stat+syst) pb, which agrees with the standard model expectation. The relative precision of 8% of this measurement is comparable to the precision of the latest theoretical calculations.
We present a model-independent measurement of t-channel electroweak production of single top quarks in pp¯ collisions at s=1.96 TeV. Using 5.4 fb−1 of integrated luminosity collected by the D0 ...detector at the Fermilab Tevatron Collider, and selecting events containing an isolated electron or muon, missing transverse energy and one or two jets originating from the fragmentation of b quarks, we measure a cross section σ(pp¯→tqb+X)=2.90±0.59(stat+syst) pb for a top quark mass of 172.5 GeV. The probability of the background to fluctuate and produce a signal as large as the one observed is 1.6×10−8, corresponding to a significance of 5.5 standard deviations.
Search for the rare decay Bs0→μ+μ Adams, M.; Alexeev, G.D.; Alton, A. ...
Physics letters. B,
10/2010, Letnik:
693, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We present the results of a search for the flavor changing neutral current decay Bs0→μ+μ− using 6.1 fb−1 of pp¯ collisions at s=1.96 TeV collected by the D0 experiment at the Fermilab Tevatron ...Collider. The observed number of Bs0 candidates is consistent with background expectations. The resulting upper limit on the branching fraction is B(Bs0→μ+μ−)<5.1×10−8 at the 95% C.L. This limit is a factor of 2.4 better than that of the previous D0 analysis and the best limit to date.
We measure the correlation between the spin of the top quark and the spin of the anti-top quark in tt¯→W+bW−b¯→ℓ+νbℓ−ν¯b¯ final states produced in pp¯ collisions at a center of mass energy s=1.96 ...TeV, where ℓ is an electron or muon. The data correspond to an integrated luminosity of 5.4 fb−1 and were collected with the D0 detector at the Fermilab Tevatron collider. The correlation is extracted from the angles of the two leptons in the t and t¯ rest frames, yielding a correlation strength C=0.10−0.45+0.45, in agreement with the NLO QCD prediction within two standard deviations, but also in agreement with the no correlation hypothesis.
PDF
