674 research outputs found
Anomalous Wtb coupling at the LHC
Some distributions of the mu- in the top quark pair production reaction pp ->
b u anti-d anti-b mu- anti-nu_mu at the LHC are calculated to leading order in
the presence of the anomalous Wtb coupling with operators of dimension up to
five. The distributions in the transverse momentum, rapidity and cosine of the
mu- angle with respect to the beam in the laboratory frame and with respect to
the reversed momentum of the b-quark in the rest frame of W-boson are changed
rather moderately by the anomalous Wtb coupling. The distributions computed
with the full set of leading order Feynman diagrams practically do not differ
from those computed with the t anti-t production diagrams, with typical
acceptance cuts. This demonstrates very little effect of the off resonance
background contributions.Comment: 17 pages, 7 figures, version accepted for publication in Acta Physica
Polonica
Top quark pair production at a linear collider in the presence of an anomalous Wtb coupling
Angular distributions of a mu+ and a b-quark resulting from the decay of a
top quark produced at the e+e- linear collider with an unpolarized and a 100%
longitudinally polarized electron beam are presented. The results of the
standard model are compared with the results obtained in the presence of the
anomalous Wtb coupling.Comment: 6 pages, 4 figures, presented by K. Cieckiewicz at the XXVII
International Coference of Theoretical Physics "Matter to the Deepest: Recent
Developments in Physics of Fundamental Interactions", Ustron, Poland,
September 15-21, 200
New developments in CARLOMAT
New developments in CARLOMAT, a program for automatic computation of the
lowest order cross sections, are presented. They include improvements of the
phase integration routines and implementation of extensions of the standard
model, such as scalar electrodynamics or the anomalous Wtb coupling including
operators of dimension up to five.Comment: Presented at the XXXV International Conference of Theoretical
Physics, "Matter to the Deepest", Ustron, Poland, September 12-18, 201
Aerothermal test results from the first flight of the Pegasus air-launched space booster
A survey of temperature measurements at speeds through Mach 8.0 on the first flight of the Pegasus air-launched booster system is discussed. In addition, heating rates were derived from the temperature data obtained on the fuselage in the vicinity of the wing shock interaction. Sensors were distributed on the wing surfaces, leading edge, and on the wing-body fairing or fillet. Side-by-side evaluations were obtained for a variety of sensor installations. Details of the trajectory reconstruction through first-stage separation are provided. Given here are indepth descriptions of the sensor installations, temperature measurements, and derived heating rates along with interpretations of the results
On the Interpretation of the Electroweak Precision Data
The recent precision electroweak data on and
are compared with the tree-level and the dominant-fermion-loop as well as the
full one-loop standard-model predictions. While the tree-level predictions are
ruled out, the dominant-fermion-loop predictions, defined by using in the tree-level formulae, as well as the full one-loop
predictions are consistent with the experimental data. Deviations from the
dominant-fermion-loop predictions are quantified in terms of an effective
Lagrangian containing three additional parameters which have a simple meaning
in terms of symmetry violation. The effective Lagrangian yields the
standard one-loop predictions for specific values of these parameters, which
are determined by and .Comment: Preprint BI-TP 93/46 (September 1993), to be published in Phys. Lett.
B, LaTeX, 10 pages, (figures are not included
Surgical treatment of lung cancer in patients under 45 years of age
Aim. The aim of the study was to evaluate the characteristics and prognosis of radical surgical treatment in young patients under the age of 45 with lung cancer. Methods. We retrospectively analysed the data of 85 young patients and 211 older patients who underwent anatomical lung resections in Wroclaw Thoracic Surgery Centre. Results. Less lobectomies were performed (p=0.048), the incidence of carcinoid was significantly higher (p<0.0001), stage I of lung cancer was observed less frequently (p=0.023), the frequency of metastasis to subcarinal lymph nodes was higher (p=0.007), a bronchial stump was microscopically infiltrated more frequently, the complete resection was noted rarer (p=0.016) and 3-year survival rate of squamous cell carcinoma patients was worse in younger group (p=0.017). The statistical significance was not observed between the frequency of recurrences and overall survival. Conclusions. Lung cancer in younger patients seems to be more advanced at the time of surgery. It is probable that the group of younger patients with squamous cell carcinoma will require additional treatment after surgery
Prognostic Role of Elevated Myeloperoxidase in Patients with Acute Coronary Syndrome: A Systemic Review and Meta-Analysis
Background. Myocardial inflammation following acute ischemic injury has been linked to poor cardiac remodeling and heart failure. Many studies have linked myeloperoxidase (MPO), a neutrophil and inflammatory marker, to cardiac inflammation in the setting of acute coronary syndrome (ACS). However, the prognostic role of MPO for adverse clinical outcomes in ACS patients has not been well established. Methods. MEDLINE and Cochrane databases were searched for studies from 1975 to March 2018 that investigated the prognostic value of serum MPO in ACS patients. Studies which have dichotomized patients into a high MPO group and a low MPO group reported clinical outcomes accordingly and followed up patients for at least 30 days to be eligible for enrollment. Data were analyzed using random-effects model. Sensitivity analyses were conducted for quality control. Results. Our meta-analysis included 13 studies with 9090 subjects and a median follow-up of 11.4 months. High MPO level significantly predicted mortality (odds ratio (OR) 2.03; 95% confidence interval (CI): 1.40-2.94; ), whereas it was not significantly predictive of major adverse cardiac events and recurrent myocardial infarction (MI) (OR 1.28; CI: 0.92-1.77, and OR 1.23; CI: 0.96-1.58, , respectively). Hypertension, diabetes mellitus, and age did not affect the prognostic value of MPO for clinical outcomes, whereas female gender and smoking status have a strong influence on the prognostic value of MPO in terms of mortality and recurrent MI (metaregression coefficient -8.616: 95% CI -14.59 to -2.633, and 4.88: 95% CI 0.756 to 9.0133, , respectively). Conclusions. Our meta-analysis suggests that high MPO levels are associated with the risk of mortality and that MPO can be incorporated in risk stratification models that guide therapy of high-risk ACS patients
B_c Meson Production in Nuclear Collisions at RHIC
We study quantitatively the formation and evolution of B_c bound states in a
space-time domain of deconfined quarks and gluons (quark-gluon plasma, QGP). At
the Relativistic Heavy Ion Collider (RHIC) one expects for the first time that
typical central collisions will result in multiple pairs of heavy (in this case
charmed) quarks. This provides a new mechanism for the formation of heavy
quarkonia which depends on the properties of the deconfined region. We find
typical enhancements of about 500 fold for the B_c production yields over
expectations from the elementary coherent hadronic B_c-meson production
scenario. The final population of bound states may serve as a probe of the
plasma phase parameters.Comment: 9 Pages, 11 Postscript Figure
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