37 research outputs found
Monte Carlo study of particle production in diffractive proton-proton collisions at = 13 TeV with the very forward detector combined with central information
Very forward (VF) detectors in hadron colliders, having unique sensitivity to
diffractive processes, can be a powerful tool for studying diffractive
dissociation by combining them with central detectors. Several Monte Carlo
simulation samples in - collisions at TeV were analyzed,
and different nondiffractive and diffractive contributions were clarified
through differential cross sections of forward neutral particles. Diffraction
selection criteria in the VF-triggered-event samples were determined by using
the central track information. The corresponding selection applicable in real
experiments has 100% purity and 30%-70% efficiency. Consequently, the
central information enables classification of the forward productions into
diffraction and nondiffraction categories; in particular, most of the surviving
events from the selection belong to low-mass diffraction events at
. Therefore, the combined method can uniquely access
the low-mass diffraction regime experimentally.Comment: 10 pages, 16 figures, 1table
The LHCf experiment at LHC
The LHCf experiment will be installed in 2007 on the LHC collider in the forward direction at ±140m from the ATLAS interaction point. The purpose of LHCf is to precisely measure the pion production cross section near zero degrees through the measurement of the photons produced in neutral pion decay. This measurement is crucial for the simulation of the showers induced in the atmosphere by very high energy cosmic rays; the 14 TeV energy available in the center of mass frame corresponds in fact to an equivalent energy of 1017 eV in the laboratory system. The paper focus on the proposed experiment and on the physics results that we expect from it
Forward photon energy spectrum at LHC 7 TeV p-p collisions measured by LHCf
Abstract The LHCf experiment is one of the LHC forward experiments. The aim is to measure the energy and the transverse momentum spectra of photons, neutrons and π 0 's at the very forward region (the pseudo-rapidity range of η > 8.4 ), which should be critical data to calibrate hadron interaction models used in the air shower simulations. LHCf successfully operated at s = 900 GeV and s = 7 TeV proton–proton collisions in 2009 and 2010. We present the first physics result, single photon energy spectra at s = 7 TeV proton–proton collisions and the pseudo-rapidity ranges of η > 10.94 and 8.81 η 8.9 . The obtained spectra were compared with the predictions by several hadron interaction models and the models do not reproduce the experimental results perfectly
The energy spectrum of forward photons measured by the RHICf experiment in sqrt{s} = 510 GeV proton-proton collisions
The Relativistic Heavy Ion Collider forward (RHICf) experiment aims at understanding the high-energy hadronic interaction by measuring the cross sections of very forward neutral particles in proton-proton collisions at = 510 GeV. For the analysis of the photon measurement, the trigger efficiency and the particle identification performance are studied by using the Monte Carlo simulation data and the experimental data. In the RHICf operation, two kinds of trigger modes (Shower, HighEM) were implemented. The trigger efficiency of the Shower trigger is 100 for photons with the energies more than 20 GeV. The HighEM trigger is designed to detect high energy photons effectively, and the trigger efficiency of the HighEM trigger is 90 for photons with the energies more than 130 GeV. The correction factor for the photon identification is calculated by using the efficiency and purity. It is found that this correction does not make a sizeable effect on the shape of the energy spectrum because the energy dependency of the factor is small
Measurement of very forward particle production at RHIC with √s=510 GeV proton-proton collisions
The Relativistic Heavy Ion Collider forward (RHICf) experiment has measured neutral particles produced in the very forward direction in the √s=510 GeV proton-proton collisions at RHIC in June 2017. The production cross sections of these particles are crucial to understand the hadronic interaction relevant to the air shower development at the cosmic-ray equivalent energy of 1.4×10 eV, just below the energy of the knee. Together with the data at LHC, accelerator data can cover the interaction in the cosmic-ray energy of 10 eV to 10 eV. In addition, RHICf is able to improve the former measurements of single-spin asymmetry in the polarized proton- proton collisions that is sensitive to the fundamental process of the meson exchange. Common data taking with the STAR experiment will shed light on the unexplored low mass diffraction process
Opportunities of OO and pO collisions at the LHC
The aim of the LHC forward (LHCf) experiment is to provide critical data to test and tune hadronic interaction models used for very high energy cosmic-ay interactions. LHCf measures neutral particles, photons, neutrinos and pi0s, at very forward region of LHC collisions, and these energetic particles significantly contribute air shower development induced by cosmic-rays. LHCf had several operations with pp and pPb collisions during Run1 and Run2 and published several results. In this talk, we will discuss about these achievement as an introduction of the following talk focusing on pO