8,099 research outputs found
Studying and production in proton-proton collisions at TeV with the ATLAS experiment
Quartic gauge couplings are tested by this study of the production of
and events in 20.2 fb of proton--proton collisions
at a centre-of-mass energy of TeV recorded with the ATLAS
detector at the LHC. The final state of events containing an
electron, a muon and a photon is analysed as well as the final states of
and production containing an electron or a muon, two jets
and a photon. For all final states two different fiducial regions are defined:
one yielding the best sensitivity to the production cross-section of the
process and one optimised for the detection of new physical phenomena. In the
former region, the production cross-section is computed and in both
regions, upper limits on the and production cross-section
are derived. The results obtained in the second phase space are combined for
the interpretation in the context of anomalous quartic gauge couplings using an
effective field theory.Comment: Proceedings of the Fifth AnnualLHC
STARlight: A Monte Carlo simulation program for ultra-peripheral collisions of relativistic ions
Ultra-peripheral collisions (UPCs) have been a significant source of study at
RHIC and the LHC. In these collisions, the two colliding nuclei interact
electromagnetically, via two-photon or photonuclear interactions, but not
hadronically; they effectively miss each other. Photonuclear interactions
produce vector meson states or more general photonuclear final states, while
two-photon interactions can produce lepton or meson pairs, or single mesons. In
these interactions, the collision geometry plays a major role. We present a
program, STARlight, that calculates the cross-sections for a variety of UPC
final states and also creates, via Monte Carlo simulation, events for use in
determining detector efficiency.Comment: 15 pages; final version with a few minor bugs correcte
Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV
We report the first measurement of charged particle elliptic flow in Pb-Pb
collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron
Collider. The measurement is performed in the central pseudorapidity region
(||<0.8) and transverse momentum range 0.2< < 5.0 GeV/. The
elliptic flow signal v, measured using the 4-particle correlation method,
averaged over transverse momentum and pseudorapidity is 0.087 0.002
(stat) 0.004 (syst) in the 40-50% centrality class. The differential
elliptic flow v reaches a maximum of 0.2 near = 3
GeV/. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow
increases by about 30%. Some hydrodynamic model predictions which include
viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/389
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
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Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV.
The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.
Particles in a pocket
Communicating science through mobile smartphone and tablet applications is
one of the most efficient ways to reach general public of diverse background
and age coverage. The Higgsy project was created in 2022 to celebrate the 10th
anniversary of the discovery of the Higgs boson at CERN. This project
introduces a mobile game to search for the Higgs boson production in a generic
particle detector. The MatterBricks is an augmented-reality project that was
created for a major national event in Belgium, held in 2023. The main features
of the two mobile applications and further prospects for reaching general
public through mobile application development process are discussed.Comment: Presented at the European Physical Society Conference on High Energy
Physics (EPS-HEP) 2023, Hamburg, German
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