The nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by the DELPHI detector at LEP. Two complementary methods are used to reconstruct the energy of weakly ...decaying b-hadrons,
. The average value of
is measured to be 0.699±0.011. The resulting
distribution is then analysed in the framework of two choices for the perturbative contribution (parton shower and Next to Leading Log QCD calculation) in order to extract measurements of the non-perturbative contribution to be used in studies of b-hadron production in other experimental environments than LEP. In the parton shower framework, data favour the Lund model ansatz and corresponding values of its parameters have been determined within PYTHIA 6.156 from DELPHI data:
with a correlation factor
ρ
=92.2%.
Combining the data on the b-quark fragmentation distributions with those obtained at the Z peak by ALEPH, OPAL and SLD, the average value of
is found to be 0.7092±0.0025 and the non-perturbative fragmentation component is extracted. Using the combined distribution, a better determination of the Lund parameters is also obtained:
with a correlation factor
ρ
=92.6%.
Single photons detected by the DELPHI experiment at LEP2 in the years 1997–2000 are reanalysed to investigate the existence of a single extra dimension in a modified ADD scenario with slightly warped ...large extra dimensions. The data collected at centre-of-mass energies between 180 and 209 GeV for an integrated luminosity of ∼650 pb
−1
agree with the predictions of the Standard Model and allow a limit to be set on graviton emission in one large extra dimension. The limit obtained on the fundamental mass scale
M
D
is 1.69 TeV/
c
2
at 95% CL, with an expected limit of 1.71 TeV/
c
2
.
A 26-year-old woman was admitted for the investigation of abdominal symptoms related to ileal Crohn's disease. The patient had been diagnosed 3 years previously with systemic sclerosis, and had been ...experiencing digestive complaints for 6 months. A first computed tomography (CT) scan showed ileal intestinal mucosal alterations, associated with a sclerolipomatosis and suspicion of ileal stenosis. An ileocolonoscopy was then performed and showed ulcers in the terminal ileum with nonspecific inflammatory changes found on biopsies, both suggesting the diagnosis of Crohn's disease. The patient was admitted for M2A capsule endoscopy, in order to clarify the respective roles of systemic sclerosis and Crohn's disease with regard to the symptoms and secondarily to determine the anatomical extent of the Crohn's lesions. A patency capsule was administered, for detection of intestinal stenosis before capsule endoscopy was done. At 30 hours after capsule ingestion, the patient complained of abdominal pain and nausea and experienced intestinal obstruction due to the blockage of the patency capsule in the ileal stenosis. The capsule dissolved after 76 hours and the patient then improved. After a few days, the patient underwent ileocecal resection. Pathological examination of the surgical specimen confirmed the presence of an ileal stenosis 17 cm in length. In some circumstances a patency capsule may dissolve slowly, leading to transitory intestinal obstruction requiring medical intervention. It should thus be used cautiously under clinical surveillance in patients with Crohn's disease.
Moments of the hadronic invariant mass and of the lepton energy spectra in semileptonic B decays have been determined with the data recorded by the DELPHI detector at LEP. From measurements of the ...inclusive b-hadron semileptonic decays, and imposing constraints from other measurements on b- and c-quark masses, the first three moments of the lepton energy distribution and of the hadronic mass distribution, have been used to determine parameters which enter into the extraction of |V_cb| from the measurement of the inclusive b-hadron semileptonic decay width. The values obtained in the kinetic scheme are: m_b(1 GeV) = 4.591 +/- 0.062 +/- 0.039 +/- 0.005 GeV/c^2 m_c(1 GeV) = 1.170 +/- 0.093 +/- 0.055 +/- 0.005 GeV/c^2 mu_{pi}^2(1 GeV) = 0.399 +/- 0.048 +/- 0.034 +/- 0.087 GeV^2 \tilde{\rho}_D^3 = 0.053 +/- 0.017 +/- 0.011 +/- 0.026 GeV^3, and include corrections at order 1/m_b^3. Using these results, and present measurements of the inclusive semileptonic decay partial width of b-hadrons at LEP, an accurate determination of |V_cb| is obtained: |V_cb| = 0.0421 x (1 +/- 0.014 (meas.) +/- 0.014 (fit) +/- 0.015 (th.)).
Abstract Background The hypothesis that some risk factors for lung cancer may have more specific associations with particular histologic types remains controversial. The aim of this study was to ...investigate possible associations between adenocarcinoma and gender, age, smoking characteristics and selected occupational carcinogens in relation to other histologic types. Methods This study included all histologically confirmed lung cancer cases diagnosed consecutively in two French University hospitals from 1997 to 2006. All medical data were obtained by face-to-face patient interviews. Occupational carcinogen exposures of each patient were assessed by an industrial hygienist. Relationships between risk factors and adenocarcinoma were analyzed by case–case comparisons using unconditional logistic regressions (ULRs). Results A total of 1493 subjects were enrolled in this study, comprising 1303 men (87.3%), 67 nonsmokers (4.5%) and 489 adenocarcinomas (32.7%). Using ULR, no associations were observed between adenocarcinoma and age, gender or smoking characteristics except for a negative relationship with smoking duration ( p < 0.0001). Significant associations were observed between ADC and exposure to welding fumes and silica in the whole population and with polycyclic aromatic hydrocarbons in ever smokers. Conclusion This study demonstrated that some risk factors, such as duration of smoking and certain occupational exposures but not gender or age, have a more important influence on the incidence of lung ADC than on other histologic types. As the distribution of histologic types may reflect underlying biological mechanisms, these findings also suggest that lung carcinogenesis pathways should be studied in relation to smoking duration and other lung cancer risk factors.
Data management in EGEE Frohner, Ákos; Baud, Jean-Philippe; Rioja, Rosa Maria Garcia ...
Journal of physics. Conference series,
01/2010, Letnik:
219, Številka:
6
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Data management is one of the cornerstones in the distributed production computing environment that the EGEE project aims to provide for a e-Science infrastructure. We have designed and implemented a ...set of services and client components, addressing the diverse requirements of all user communities. LHC experiments as main users will generate and distribute approximately 15 PB of data per year worldwide using this infrastructure. Another key user community, biomedical projects, have strict security requirements with less emphasis on the volume of data. We maintain three service groups for grid data management: The Disk Pool Manager (DPM) Storage Element (with more than 100 instances deployed world-wide), the LCG File Catalogue (LFC) and the File Transfer Service (FTS) which sustains an aggregated transfer rate of 1.5GB/sec. They are complemented by individual client components and also tools which help coordinating more complex uses cases with multiple services (GFAL-client, lcg util, eds-cli). In this paper we show how these services, keeping clean and standard interfaces among each other, can work together to cover the data flow and how they can be used as individual components to cover diverse requirements. We will also describe areas that we consider for further improvements, both for performance and functionality.
The DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air. The cosmic events were recorded in “parasitic mode” between individual e
+e
− ...interactions and the total live time of this data taking is equivalent to 1.6
×
10
6
s. The DELPHI apparatus is located about 100
m underground and the 84 metres rock overburden imposes a cutoff of about 52
GeV/c on muon momenta. The data from the large volume Hadron Calorimeter allowed the muon multiplicity of 54,201 events to be reconstructed. The resulting muon multiplicity distribution is compared with the prediction of the Monte Carlo simulation based on CORSIKA/QGSJET01. The model fails to describe the abundance of high multiplicity events. The impact of QGSJET internal parameters on the results is also studied.
Moments of the hadronic invariant mass and of the lepton energy spectra in semileptonic B decays have been determined with the data recorded by the DELPHI detector at LEP. From measurements of the ...inclusive b-hadron semileptonic decays, and imposing constraints from other measurements on b- and c-quark masses, the first three moments of the lepton energy distribution and of the hadronic mass distribution, have been used to determine parameters which enter into the extraction of |Vcb| from the measurement of the inclusive b-hadron semileptonic decay width. The values obtained in the kinetic scheme are:\(\begin{array}{*{20}l}{{m_{b} {\left( {1\;{\text{GeV}}} \right)}} \hfill} & { = \hfill} & {{4.591 \pm 0.062 \pm 0.039 \pm 0.005\;{\text{GeV/c}}^{2} ,} \hfill} \\{{m_{c} {\left( {1\;{\text{GeV}}} \right)}} \hfill} & { = \hfill} & {{1.170 \pm 0.093 \pm 0.055 \pm 0.005\;{\text{GeV/c}}^{{\text{2}}} {\text{,}}} \hfill} \\{{\mu ^{2}_{\pi } {\left( {1\;{\text{GeV}}} \right)}} \hfill} & { = \hfill} & {{0.399 \pm 0.048 \pm 0.034 \pm 0.087\;{\text{GeV}}^{{\text{2}}} {\text{,}}} \hfill} \\{{ \ifmmode\expandafter\tilde\else\expandafter\~\fi{\rho }^{3}_{D} } \hfill} & { = \hfill} & {{0.053 \pm 0.017 \pm 0.011 \pm 0.026\;{\text{GeV}}^{{\text{3}}} ,} \hfill} \\\end{array} \)and include corrections at order 1/mb3. Using these results, and present measurements of the inclusive semileptonic decay partial width of b-hadrons at LEP, an accurate determination of |Vcb| is obtained: \({\left| {V_{{cb}} } \right|} = 0.0421 \times {\left( {1 \pm 0.014_{{{\text{meas}}{\text{.}}} \pm 0.014_{{{\text{fit}}} \pm 0.015_{{{\text{th}}{\text{.}}} } \right)}\)
The Physics of the B Factories Bevan, Adrian; Golob, Bostjan; Mannel, Thomas ...
European physical journal. C, Particles and fields,
March 2015, Letnik:
74, Številka:
11
eBook, Journal Article
Recenzirano
Odprti dostop
This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related ...issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C.
An analysis of the direct soft photon production rate as a function of the parent jet characteristics is presented, based on hadronic events collected by the DELPHI experiment at LEP1. The ...dependences of the photon rates on the jet kinematic characteristics (momentum, mass, etc.) and on the jet charged, neutral and total hadron multiplicities are reported. Up to a scale factor of about four, which characterizes the overall value of the soft photon excess, a similarity of the observed soft photon behavior to that of the inner hadronic bremsstrahlung predictions is found for the momentum, mass, and jet charged multiplicity dependences. However for the dependence of the soft photon rate on the jet neutral and total hadron multiplicities a prominent difference is found for the observed soft photon signal as compared to the expected bremsstrahlung from final state hadrons. The observed linear increase of the soft photon production rate with the jet total hadron multiplicity and its strong dependence on the jet neutral multiplicity suggest that the rate is proportional to the number of quark pairs produced in the fragmentation process, with the neutral pairs being more effectively radiating than the charged ones.
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