2,894 research outputs found
Exclusive Jet Measurement in Special LHC Runs - Feasibility Studies
The feasibility studies of the central exclusive jet production at the LHC
using the proton tagging technique are presented. Three classes of data taking
scenarios are considered: double tag at high pile-up, single tag at low pile-up
and double tag at low pile-up. Analyses were performed at the c.m. energy of 14
TeV for the ATLAS experiment, but are also valid for the CMS/TOTEM detectors.Comment: Presented at XXII Cracow Epiphany Conferenc
Hard Diffraction with Proton Tagging at the LHC
The main parts of the LHC diffractive physics programme possible to be
measured using a proton tagging technique are presented. The geometric
acceptance of the ATLAS forward proton detectors: ALFA and AFP for various LHC
optics settings are shown. The probabilities of observing a proton originating
from a minimum-bias event in ALFA and AFP stations are given. The main
properties of single diffractive and double Pomeron exchange production of
dijets, photon+jet, jet-gap-jet and W/Z bosons are discussed. The possibility
of measuring the jet production in exclusive (double proton tag) and
semi-exclusive (single tag) mode is evaluated
Machine Optics Studies for the LHC Measurements
In this work the properties of scattered protons in the vicinity of the ATLAS
Interaction Point (IP1) for various LHC optics settings are discussed. Firstly,
the beam elements installed around IP1 are presented. Then the ATLAS forward
detector systems: Absolute Luminosity For ATLAS (ALFA) and ATLAS Forward
Protons (AFP) are described and their similarities and differences are
discussed. Next, the various optics used at Large Hadron Collider (LHC) are
described and the beam divergence and width at the Interaction Point as well as
at the ATLAS forward detectors locations are calculated. Finally, the geometric
acceptance of the ATLAS forward detectors is shown and the impact of the LHC
collimators on it is discussed.Comment: 15 pages, 10 figure
On the Possibility of Measuring the Single-tagged Exclusive Jets at the LHC
The feasibility studies of the measurement of the central exclusive jet
production at the LHC using the proton tagging technique are presented. In
order to reach the low jet-mass region, single tagged events were considered.
The studies were performed at the c.m. energy of 14 TeV and the ATLAS detector,
but are also applicable for the CMS-TOTEM experiments. Four data-taking
scenarios were considered: AFP and ALFA detectors as forward proton taggers and
= 0.55 m and = 90 m optics. After the event selection, the
signal-to-background ratio ranges between 5 and . Finally, the expected
precision of the central exclusive dijet cross-section measurement for data
collection period of 100 h is estimated
Gaps between jets in double-Pomeron-exchange processes at the LHC
The possibility to measure jet-gap-jet final states in
double-Pomeron-exchange events at the LHC is presented. In the context of the
ATLAS experiment with additional forward physics detectors, cross sections for
different experimental settings and gap definitions are estimated. This is done
in the framework of the Forward Physics Monte Carlo interfaced with a
perturbative QCD model that successfully reproduces standard jet-gap-jet cross
sections at the Tevatron. The extrapolation to LHC energies follows from the
Balitsky-Fadin-Kuraev-Lipatov dynamics, implemented in the model at
next-to-leading logarithmic accuracy.Comment: 8 pages, 5 figures, version to appear in PR
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