3,188 research outputs found
The AFP Project
AFP is a project to extend the diffractive physics programme of the ATLAS
experiment by installing new detectors that will be able to tag forward protons
scattered at very small angles. This will allow us to study Single Diffraction,
Double Pomeron Exchange, Central Exclusive Production and photon-photon
processes. This note presents the physics case for the AFP project and briefly
describes the proposed detector system.Comment: 10 pages, 8 figures, presented at the Cracow Epiphany Conference on
the first year of the LHC, Cracow, Poland, January 10--12, 201
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
Cloning by limiting dilution: an improved estimate that an interesting culture is monoclonal.
An interesting culture obtained by limiting dilution is less likely to be monoclonal than a random viable culture. Current practice using limiting dilution to establish monoclonal lines of interesting recombinant DNA or hybridoma-derived organisms overestimates the probability that promising cultures are monoclonal, resulting in inadequate dilutions, with the need for additional subcloning and the avoidable loss (avoidable instability) of interesting lines by overgrowth with uninteresting varieties
Diffractive Bremsstrahlung at High- LHC Case Study
Feasibility studies of the measurement of the exclusive diffractive
bremsstrahlung cross-section in proton-proton scattering at the centre of mass
energy of 13 TeV at the LHC are reported. Present studies were performed for
the low luminosity LHC running with the betatron function value of 90~m using
the ATLAS associated forward detectors ALFA and ZDC. A simplified approach to
the event simulation and reconstruction is used. The background influence is
also discussed.Comment: 20 pages, 10 figures. arXiv admin note: substantial text overlap with
arXiv:1603.0644
Uncertainties on exclusive diffractive Higgs and jets production at the LHC
Two theoretical descriptions of exclusive diffractive jets and Higgs
production at the LHC were implemented into the FPMC generator: the Khoze,
Martin, Ryskin model and the Cudell, Hern\'andez, Ivanov, Dechambre exclusive
model. We then study the uncertainties. We compare their predictions to the CDF
measurement and discuss the possibility of constraining the exclusive Higgs
production at the LHC with early measurements of exclusive jets. We show that
the present theoretical uncertainties can be reduced with such data by a factor
of 5
Exclusive Production at the LHC with Forward Proton Tagging
A process of Central Exclusive production in proton-proton
collisions and its theoretical description is presented. A possibility of its
measurement, during the special low luminosity LHC runs, with the help of the
ATLAS central detector for measuring pions and the ALFA stations for tagging
the scattered protons is studied. A visible cross section is estimated to be 21
b for TeV, which gives over 2000 events for 100 b
of integrated luminosity. Differential distributions in pion pseudorapidities,
pion and proton transverse momenta as well as invariant mass are
shown and discussed.Comment: 9 pages, 7 figure
Feasibility Studies of the Diffractive Bremsstrahlung Measurement at the LHC
Feasibility studies of an observation of the exclusive diffractive
bremsstrahlung in proton-proton scattering at the LHC are reported. A
simplified approach to the photon and the scattered proton energy
reconstruction is used. The background influence is discussed.Comment: 15 pages, 6 figure
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