1,721,150 research outputs found
Study of the t-channel single top quark production and decay through t → Wb → eνb at LHC with the CMS Experiment
No full textThe thesis presents a data analysis work performed in the context of the CMS experiment at the LHC, with the aim of measuring the cross section of single top produced in t-channel and decaying through t → Wb → eνb.
First a brief introduction on the Standard Model of elementary particles is given, followed by a description of the LHC accelerator and the CMS detector. Then the main physics results obtained by LHC in the first years of data-taking are presented and a section devoted to theoretical and experimental state of the art concerning the top quark physics concludes the introductory part of the thesis. The last two chapter are dedicated to a detailed description of the analysis performed. It is based on data collected by CMS in 2010, corresponding to an integrated luminosity of 36.1/pb, with an update using 920.7/pb of 2011 data taking. The measurement of single top t-channel cross section is in the end reported together with a measurement of the CKM matrix element |Vtb|
Measurement of the single top quark -channel cross section with a template fit analysis
No full textWe present a measurement of the inclusive single top -channel production cross section in proton-proton collisions at the LHC, using data collected with the CMS experiment during 2011 and 2012. The analyzed data correspond to an integrated luminosity of 1.17/1.56~fb for muon/electron channel respectively at the centre-of-mass energy of 7 TeV, and to 5.0~fb at 8 TeV. The analysis exploits the pseudorapidity distribution of the recoil jet and reconstructed top-quark mass using background estimates determined from control samples in data. The measurement is used to determine the CKM matrix element
Belle II experiment status and measurement perspectives
Full text linkThe Belle II experiment is a multi-purpose flavour physics facility designed to collect electron-positron collision data at the unprecedented instantaneous luminosity of 0.8×10−36 cm−2s−1. The former collider KEKB and the Belle detector are undergoing important upgrades in order to achieve the high-luminosity collision scheme and to sustain the enhanced level of backgrounds. The unique capabilities of this new machine will allow to study a wide range Standard Model (SM) processes with an unequalled precision and to perform beyond SM searches up to now inaccessible
Study of the single top production in the -channel with the CMS experiment at the LHC
Full text linkWe present a measurement of the inclusive single top -channel production cross section in proton-proton collisions at the LHC, using data collected with the CMS experiment in 2011 and 2012 at a centre-of-mass energy of 7 TeV and 8 TeV, respectively. The 7 TeV analysis makes use of two different and complementary approaches. The first is a template fit analysis using background estimates determined from control samples in data. The second is based on multivariate techniques that probe the compatibility of the candidate events with the signal. The update of the template fit analysis with 8 TeV data is also presented together with the measurement of the -channel single top quark and anti-quark production ratio. The cross section measurements are also used to determine the CKM matrix element $\lvert V_{\text{tb}}\rvert
Measurement of single top production in the tW-channel and search for s-channel in pp collisions
No full textPreface of the fourth workshop on theory, phenomenology and experiments in heavy flavour physics
No full textProgetto di un Acciaio ad Elevate Prestazioni ed a Basso Impatto Ambientale per l'Impiego in un Reattore a Fusione Nucleare
No full textAbstract not availableNA - NOT AVAILABL
The Design of Low-Activation Steels for a Fusion Reactor First Wall. A Proposal for a New Austenitic Alloy
No full textAbstract not availableNA - NOT AVAILABL
Safety and environmental advantages of breeding blanketless fusion reactors
No full textNext-step reactors will use DT cycle. However, environmental advantage will be the main chance for fusion to compete with other energy sources. The environmental problems of DT cycle due to tritium and neutron activation, are examined. Fusion commercial reactors could be based on alternative fuel cycles like D-He3. Advantages and disadvantages of this fuel cycle are outlined. All the technologies related with the self-breeding of tritium and the concept of breeding blanket itself may be not reactor relevant. In the frame of the Next-step studies, the potential advantages of intermediate DT devices without breeding blanket are discussed. Simplified design, lower cost, higher safety are the main ones. The problem of the source of tritium is examine
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