Neutral triple-gauge-boson couplings ZZZ, ZZγ and Zγγ have been studied with the DELPHI detector using data at energies between 183 and 208 GeV. Limits are derived on these couplings from an analysis ...of the reactions e+e-→Zγ, using data from the final states γff̄, with f=q or ν, from e+e-→ZZ, using data from the four-fermion final states qq̄qq̄, qq̄μ+μ-, qq̄e+e-, qq̄νν̄, μ+μ-νν̄ and e+e-νν̄, and from e+e-→Zγ*, in which the final state γ is off mass-shell, using data from the four-fermion final states qq̄e+e- and qq̄μ+μ-. No evidence for the presence of such couplings is observed, in agreement with the predictions of the Standard Model.
Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qq disintegrations of the Z(0) were studied in the kinematic range 0.2 < E-y < I GeV and ...transverse momentum with respect to the closest jet direction P-T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/- 0.27) x 10(-3) gamma/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340 +/- 0.001 +/- 0.038) X 10(-3) gamma/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.
Single top quark production via four-fermion contact interactions associated to flavour-changing neutral currents was searched for in data taken by the DELPHI detector at LEP2. The data were ...accumulated at centre-of-mass energies ranging from 189 to 209 GeV, with an integrated luminosity of 598.1 pb
−1
. No evidence for a signal was found. Limits on the energy scale
Λ
, were set for scalar-, vector- and tensor-like coupling scenarios.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVES
Nutritional assessment is not included yet as a major recommendation in lung cancer guidelines. The purpose of this study was thus to assess the influence on surgical outcome of the ...nutritional status of patients with primary lung cancer undergoing lobectomy.
METHODS
We queried Epithor, the national clinical database of the French Society of Thoracic and Cardiovascular Surgery, and identified a retrospective cohort of 19 635 patients having undergone lobectomy for a primary lung cancer in the years 2005-11. Their nutritional status was categorized according to the WHO definition: underweight (BMI < 18.5): 857 patients (4.4%), normal (18.5 ≤ BMI < 25): 9391 patients (47.8%), overweight (25 ≤ BMI < 30): 6721 patients (34.2%), obese (BMI ≥ 30): 2666 patients (13.6%). Operative mortality, pulmonary, cardiovascular, infectious and surgical complications rates were collected and analysed for these various BMI groups.
RESULTS
In the normal-weight category, operative mortality, pulmonary, surgical, cardiovascular and infectious complications rates were 2.7, 14.6, 13.8, 5.5 and 4.1%, respectively. When compared with that of normal BMI patients, adjusted operative mortality was significantly lower in overweight (2.3%; odd ratio (OR): 0.72 95% confidence interval (CI): 0.59-0.89; P = 0.002) and obese patients (1.9%, OR: 0.54 95% CI: 0.40-0.74; P < 0.001), and significantly higher in underweight patients (4.1%, OR: 1.89 95% CI: 1.30-2.75; P = 0.001). Underweight patients experienced significantly more pulmonary (21.1%; P < 0.001), surgical (23.2%; P < 0.001) and infectious (5.1%; P = 0.05) complications (P < 0.0001). Among surgical complications, prolonged air leaks (17.6%; P < 0.001) and bronchial stump dehiscence (1.5%; P = 0.001) were significantly more frequent in underweight patients than in normal BMI patients. Obesity was not associated with increased incidence of postoperative complications, except for arrhythmia (5.6%; P < 0.05), deep venous thrombosis and pulmonary embolism (1.5%; P = 0.005). Moreover, a statistical protective effect of obesity was observed regarding surgical complications (7.1%; P < 0.001).
CONCLUSIONS
Despite having an increased risk of some postoperative cardiovascular complications, obese patients should undergo surgical standard of care therapy for appropriately stage-specific lung cancer. In underweight patients, in addition to preoperative rehabilitation including a nutritional program, attention should be given to aggressive prophylactic respiratory therapy in the perioperative period, and specific intraoperative actions to prevent prolonged air leaks and bronchial stump dehiscence.
Searches for lepton-flavor-violating decays of a tau lepton to a lighter mass lepton and a photon have been performed with the entire data set of (963+/-7)x10{6} tau decays collected by the BABAR ...detector near the Upsilon(4S), Upsilon(3S) and Upsilon(2S) resonances. The searches yield no evidence of signals and we set upper limits on the branching fractions of B(tau{+/-}-->e{+/-}gamma)<3.3x10{-8} and B(tau{+/-}-->mu{+/-}gamma)<4.4x10{-8} at 90% confidence level.
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for pair-produced charged Higgs bosons in the framework of Two Higgs Doublet Models (2HDMs). The data of the four experiments ...have been statistically combined. The results are interpreted within the 2HDM for Type I and Type II benchmark scenarios. No statistically significant excess has been observed when compared to the Standard Model background prediction, and the combined LEP data exclude large regions of the model parameter space. Charged Higgs bosons with mass below 80
(Type II scenario) or 72.5
(Type I scenario, for pseudo-scalar masses above 12
) are excluded at the 95 % confidence level.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A precise measurement of the cross section of the process $e^+e^-\to\pi^+\pi^-(\gamma)$ from threshold to an energy of 3GeV is obtained with the initial-state radiation (ISR) method using $232\invfb$ ...of data collected with the BaBar detector at $e^+e^-$ center-of-mass energies near 10.6GeV. The ISR luminosity is determined from a study of the leptonic process $e^+e^-\to\mu^+\mu^-(\gamma)\gamma_{\rm ISR}$, which is found to agree with the next-to-leading-order QED prediction to within 1.1%. The cross section for the process $e^+e^-\to\pi^+\pi^-(\gamma)$ is obtained with a systematic uncertainty of 0.5% in the dominant $\rho$ resonance region. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured $\pi\pi$ cross section from threshold to 1.8GeV is $(514.1 \pm 2.2({\rm stat}) \pm 3.1({\rm syst}))\times 10^{-10}$.
Neutral triple-gauge-boson couplings ZZZ, ZZγ and Zγγ have been studied with the DELPHI detector using data at energies between 183 and 208 GeV. Limits are derived on these couplings from an analysis ...of the reactions e + e - →Zγ, using data from the final states γff̄, with f=q or ν, from e + e - →ZZ, using data from the four-fermion final states qq̄qq̄, qq̄μ + μ - , qq̄e + e - , qq̄νν̄, μ + μ - νν̄ and e + e - νν̄, and from e + e - →Zγ * , in which the final state γ is off mass-shell, using data from the four-fermion final states qq̄e + e - and qq̄μ + μ - . No evidence for the presence of such couplings is observed, in agreement with the predictions of the Standard Model.
We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron–positron colliders SLC and LEP. The data consist of 17 ...million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forward–backward asymmetries and polarised asymmetries. The mass and width of the Z boson,
m
Z
and
Γ
Z
, and its couplings to fermions, for example the
ρ
parameter and the effective electroweak mixing angle for leptons, are precisely measured:
m
Z
=
91.1875
±
0.0021
GeV
,
Γ
Z
=
2.4952
±
0.0023
GeV
,
ρ
ℓ
=
1.0050
±
0.0010
,
sin
2
θ
eff
lept
=
0.23153
±
0.00016
.
The number of light neutrino species is determined to be
2.9840
±
0.0082
, in agreement with the three observed generations of fundamental fermions.
The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward–backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations.
Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark,
m
t
=
173
-
10
+
13
GeV
, and the mass of the W boson,
m
W
=
80.363
±
0.032
GeV
. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of
m
t
and
m
W
, the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than
285
GeV
at 95% confidence level.
A precise measurement of the cross section of the process e(+)e(-) --> pi(+)pi(-)(gamma) from threshold to an energy of 3 GeV is obtained with the initial state radiation (ISR) method using 232 ...fb(-1) of data collected with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV. The ISR luminosity is determined from a study of the leptonic process e(+)e(-) --> mu(+)mu(-)gamma(gamma). The leading-order hadronic contribution to the muon magnetic anomaly calculated using the pipi cross section measured from threshold to 1.8 GeV is (514.1 +/- 2.2(stat) +/- 3.1(syst)) x 10(-10).
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