Search results for " Collider"
showing 10 items of 1415 documents
Angular analysis of charged and neutral B → Kμ + μ − decays
2014
The angular distributions of the rare decays B → K+µ+µ- and B0 → K0 <inf>a</inf>Sμ+μ- are studied with data corresponding to 3 fb-1 of integrated luminosity, collected in proton-proton collisions at 7 and 8TeV centre-of-mass energies with the LHCb detector. The angular distribution is described by two parameters, FH and the forward-backward asymmetry of the dimuon system AFB, which are determined in bins of the dimuon mass squared. The parameter F<inf>H</inf> is a measure of the contribution from (pseudo)scalar and tensor amplitudes to the decay width. The measurements of A<inf>FB</inf> and F<inf>H</inf> reported here are the most precise to d…
Measurement of CP asymmetry in Bs0 → Ds ∓K± decays
2014
Journal of high energy physics 2018(3), 59 (2018). doi:10.1007/JHEP03(2018)059
Observation of an Excited $B^{\pm}_c$ Meson State with the ATLAS Detector
2014
A search for excited states of the B±c meson is performed using 4.9 fb-1 of 7 TeV and 19.2 fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay B±c→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5 MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the B±c meson, B±c(2S).
Search for a fermiophobic Higgs at LEP 2
2001
Higgs bosons predicted by the fermiophobic scenario within Two Higgs Doublets Models were searched for in the data collected by the DELPHI detector at centre-of-mass energies between 189 GeV and 202 GeV, corresponding to a total integrated luminosity of 380 pb^{-1}. No signal was found and confidence limits were derived in the framework of possible extensions of the Standard Model Higgs sector.
Top-quark pair + 1-jet production at next-to-leading order QCD
2008
Top-quark pair production with an additional jet is an important signal and background process at the LHC. We present the next-to-leading order QCD calculation for this process and show results for integrated as well as differential cross sections.
Charm production in the CERN hyperon beam
1994
First results on charm production by the Σ- hyperon beam experiment WA89 at CERN are presented. Estimates are given for thexF and nuclearA dependence of the inclusive cross-section of D-mesons. Preliminary results on charm baryon production are shown.
Big Data Processing in the ATLAS Experiment: Use Cases and Experience
2015
Abstract The physics goals of the next Large Hadron Collider run include high precision tests of the Standard Model and searches for new physics. These goals require detailed comparison of data with computational models simulating the expected data behavior. To highlight the role which modeling and simulation plays in future scientific discovery, we report on use cases and experience with a unified system built to process both real and simulated data of growing volume and variety.
Multi-channel search for squarks and gluinos in root s=7 TeV pp collisions with the ATLAS detector at the LHC
2013
A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from b-quarks, in 4.7 fb[superscript −1] of √s = 7 TeV pp collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse and parallel to the beam line that are sensitive to several topologies expected in supersymmetry. Mutually exclusive final states are defined, allowing a combination of all channels to increase the search sensitivity. No deviation from the Standard Model expectation is observed. Upper limits at 95 % confidence level…
ALICE forward rapidity upgrades
2017
Two forward rapidity upgrades of the ALICE apparatus at the LHC are presented: the Muon Forward Tracker (MFT) and the Fast Interaction Trigger (FIT). Their designs are driven by physics performance studies, which have been done using MC simulations. Several prototypes have been tested. Currently the detector design phase has ended. The final layouts, geometries and expected performance figures are presented. The latest developments from the test of the prototypes are discussed. The MFT will improve the performance of the ALICE Muon Spectrometer by adding vertexing capabilities to the system. The elementary component of the MFT is a Monolithic Active Pixel Sensor (MAPS), using the TowerJazz …
Update on the TowerJazz CMOS DMAPS development for the ATLAS ITk
2019
The upgrade of the ATLAS tracking detector for the High-Luminosity Large Hadron Collider at CERN requires the development of novel radiation hard silicon sensor technologies. For the de- velopment of depleted CMOS sensors for ATLAS we combined small electrodes with minimal capacitance and advanced processing for fully depleted active sensor volume to achieve radiation hard CMOS sensors in line with ATLAS ITk specifications. Based on initial studies on the prototype sensor “TowerJazz Investigator” we have now developed, produced and tested a first full-size depleted CMOS sensor based on the 180nm TowerJazz imag- ing process, the so-called “MALTA” sensor. The sensor combines special low-noise…