583 research outputs found
Tevatron - probing TeV-scale gravity today
No full textThe production of black holes at Tevatron and LHC in spacetimes with compactified space-like large extra dimensions is studied. Either black holes can already be observed in ¯ pp collisions at s = 1.8 TeV or the fundamental gravity scale has to be above 1.4 TeV. At LHC the creation of a large number of quasi-stable black holes is predicted, with lifetimes beyond several hundred fm/c. A cut-off in the high-PT jet cross section is shown to be a unique signature of black hole production. This signal is compared to the jet plus missing energy signature due to graviton production in the final state as proposed by the ATLAS collaboration
Searches for resonances at LHC and Tevatron
No full textSlides for plenary talk at LHCP2013 on Searches for resonances at LHC and Tevatron (BSM1 session)
Quelques aspects de la physique auprès des collisionneurs hadroniques en préparation à la physique au LHC
No full textEtiquetage des quarks par un détecteur de vertex à pixels dans l'expérience ATLAS auprès du LHC
No full textThe capability of the \atlas~detector to tag -jets is studied, usin g the impact parameter of charged tracks. High -tagging performance is needed at \lhc, especially during the first years of running, in order to see evidence of the Higgs boson if its mass lies between 80 and 120 GeV. A pattern-recognition algorithm has been developed for this purpose, using a detailed simulation of the \atlas~inner detector. Track-findin g starts from the pixel detector layers. A "hyper-plane" concept allows the use of a simple tracking algorithm though the complex geome try. High track-finding efficiency and reconstruction quality ensure the discrimination of -jets from other kinds of jets. After full simulation and reconstruction of , , , and events ( GeV), the mean rejections achieved against non--jets for a 50\% -jet tagging efficiency are as follows: \vspace{-5mm} \begin{Tabhere}\centering \begin{tabular}{cccc} \hspace{3cm} & \hspace{3cm} & \hspace{3cm} & \hspace{3cm} \\ & & & \\ \end{tabular} \end{Tabhere} The analysis of data from the first radiation-hard pixel detector prototypes justifies the potential of these detectors for track-finding and high-precision impact parameter measurement at~\lhc
Prospects for b-tagging in ATLAS and tracking commissioning results with cosmic rays
No full textThe ability to identify jets containing B hadrons is important for the high-pT physics program of a general-purpose experiment at the LHC such as ATLAS. This capability relies on the very accurate measurements of the parameters of charged tracks provided by the ATLAS Inner Detector. Using millions of cosmic-ray tracks collected during the automn 2008, the ATLAS Inner Detector has been aligned and its tracking performance assessed. Some of the very encouraging results which have been obtained and are relevant for b-tagging are discussed, notably the current level of alignment of the detector and the resolution on the transverse impact parameter of tracks. The various b-tagging algorithms are then described, and their anticipated performance discussed in the light of the cosmic-ray data results. Finaly,the expected accuracy with which the b-tagging performance will be measured in data is mentioned
b-tagging with ATLAS
No full textThe ability to identify jets containing b-hadrons is important for the high-pT physics program of a general-purpose experiment at the LHC such as ATLAS. This is in particular useful to select very pure top samples, to search and/or study Standard Model or supersymmetric Higgs bosons which couple preferably to heavy objects or are produced in association with heavy quarks, to veto the large dominant ttbar background for several physics channels and finally to search for new physics: SUSY decay chains, heavy gauge bosons, etc. After a review of the algorithms used to identify b-jets, their anticipated performance is discussed as well as the impact of various critical ingredients such as the residual misalignments in the tracker. The prospects to measure the b-tagging performance in the first few hundreds pb-1 of data with di-jet events and ttbar events are then discussed. Finally three different use cases are discussed: the top mass measurement, the search for a low-mass Higgs boson produced in association with a top quark pair and decaying to bbbar, and the specific challenges of tagging very high-pT (TeV) jets for exotics searches
Recommended from our members
Masses, lifetimes, and decays of B hadrons at the Tevatron
No full textThe latest results in B physics from the CDF and D0 experiments at the Tevatron are presented, including inclusive b lifetime measurement, exclusive lifetime measurement of the B{sub s}. Promising samples collected by CDF with its Secondary Vertex Trigger are shown as well
- …
