183 research outputs found
Photoproduction with a mini-jet model and Cosmic Ray showers
We present post-LHC updates of estimates of the total photo-production cross
section in a mini-jet model with infrared soft gluon resummation, and apply the
model to study Cosmic Ray shower development, comparing the results with those
obtained from other existing models.Comment: 7 pages, 5 figures, presented at Photon 2017, 22-26 May 2017 CER
Ultra-peripheral collisions of charged hadrons in extensive air showers
We discuss the electromagnetic collisions of high energy protons, pions and
kaons with atmospheric nuclei. In particular, we use the equivalent photon
approximation to estimate (i) the diffractive collisions where the projectile
scatters inelastically off a nucleus, and (ii) the usual radiative processes
(bremsstrahlung, pair production and photonuclear interactions) of these
charged hadrons in the air. We then include the processes in the simulator
AIRES and study how they affect the longitudinal development of extensive air
showers. For GeV proton primaries we find that they introduce a
very small reduction (below 1%) in the average value of both and
. At a given shower age (relative slant depth from ), these electromagnetic processes do not change significantly the number
of muons or the total energy carried by electrons and photons, increased by
just 1% the muon-to-() signal at the ground level.Comment: references added, typos correcte
Production and propagation of heavy hadrons in air-shower simulators
Very energetic charm and bottom hadrons may be produced in the upper atmosphere when a primary cosmic ray or the leading hadron in an extensive air shower collide with a nucleon. At E≈108 GeV their decay length becomes of order 10 km, implying that they tend to interact in the air instead of decaying. Since the inelasticity in these collisions is much smaller than the one in proton and pion collisions, there could be rare events where a heavy-hadron component transports a significant amount of energy deep into the atmosphere. We have developed a module for the detailed simulation of these processes and have included it in a new version of the air shower simulator AIRES. We study the frequency, the energy distribution and the depth of charm and bottom production and decay in the atmosphere. As an illustration, we consider the production and decay of tau leptons (from Ds decays) and the lepton flux at PeV energies from a 30 EeV proton primary. The proper inclusion of charm and bottom hadrons in AIRES opens the possibility to search for air-shower observables that are sensitive to heavy quark effects.Instituto de FÃsica La PlataConsejo Nacional de Investigaciones CientÃficas y Técnica
Production and propagation of heavy hadrons in air-shower simulators
Very energetic charm and bottom hadrons may be produced in the upper atmosphere when a primary cosmic ray or the leading hadron in an extensive air shower collide with a nucleon. At E≈108 GeV their decay length becomes of order 10 km, implying that they tend to interact in the air instead of decaying. Since the inelasticity in these collisions is much smaller than the one in proton and pion collisions, there could be rare events where a heavy-hadron component transports a significant amount of energy deep into the atmosphere. We have developed a module for the detailed simulation of these processes and have included it in a new version of the air shower simulator AIRES. We study the frequency, the energy distribution and the depth of charm and bottom production and decay in the atmosphere. As an illustration, we consider the production and decay of tau leptons (from Ds decays) and the lepton flux at PeV energies from a 30 EeV proton primary. The proper inclusion of charm and bottom hadrons in AIRES opens the possibility to search for air-shower observables that are sensitive to heavy quark effects.Instituto de FÃsica La PlataConsejo Nacional de Investigaciones CientÃficas y Técnica
A new observable in extensive air showers
We find that the ratio rμe of the muon to the electromagnetic component of an extended air shower at the ground level provides an indirect measure of the depth Xmax of the shower maximum. This result, obtained with the air-shower code AIRES, is independent of the hadronic model used in the simulation. We show that the value of rμe in a particular shower discriminates its proton or iron nature with a 98% efficiency. We also show that the eventual production of forward heavy quarks inside the shower may introduce anomalous values of rμe in isolated events.Facultad de Ciencias ExactasInstituto de FÃsica La Plat
Hunting long-lived gluinos at the Pierre Auger Observatory
A ps version of the paper with high resolution figures is available at: http://www.hep.physics.neu.edu/staff/doqui/rhadron_highres.psEventual signals of split sypersymmetry in cosmic ray physics are analyzed in detail. The study focusses particularly on quasi-stable colorless R-hadrons originating through confinement of long-lived gluinos (with quarks, anti-quarks, and gluons) produced in pp collisions at astrophysical sources. Because of parton density requirements, the gluino has a momentum which is considerable smaller than the energy of the primary proton, and so production of heavy (mass ~ 500 GeV) R-hadrons requires powerful cosmic ray engines able to accelerate particles up to extreme energies, somewhat above 10^{13.6} GeV. Using a realistic Monte Carlo simulation with the AIRES engine, we study the main characteristics of the air showers triggered when one of these exotic hadrons impinges on a stationary nucleon of the Earth atmosphere. We show that R-hadron air showers present clear differences with respect to those initiated by standard particles. We use this shower characteristics to construct observables which may be used to distinguish long-lived gluinos at the Pierre Auger Observatory.Peer reviewe
An explanation of the muon puzzle of ultrahigh-energy cosmic rays and the role of the Forward Physics Facility for model improvement
We investigate the observed muon deficit in air shower simulations when
compared to ultrahigh-energy cosmic ray (UHECR) data. Based upon the observed
enhancement of strangeness production in high-energy hadronic collisions
reported by the ALICE Collaboration, the concomitant
swap is considered as the keystone to resolve the muon anomaly through its
corresponding impact on the shower development. We construct a toy model in
terms of the swapping probability . We present a
parametrization of in terms of the pseudorapidity that can accommodate
the UHECR data. Looking to the future, we explore potential strategies for
model improvement using the massive amounts of data to be collected by LHC
neutrino detectors, such as FASER and experiments at the Forward Physics
Facility. We calculate the corresponding sensitivity to and show that
these experiments will be able to probe the model phase space.Comment: To be published in JHEA
Hunting long-lived gluinos at the Pierre Auger Observatory
Eventual signals of split sypersymmetry in cosmic ray physics are analyzed in
detail. The study focusses particularly on quasi-stable colorless R-hadrons
originating through confinement of long-lived gluinos (with quarks,
anti-quarks, and gluons) produced in pp collisions at astrophysical sources.
Because of parton density requirements, the gluino has a momentum which is
considerable smaller than the energy of the primary proton, and so production
of heavy (mass ~ 500 GeV) R-hadrons requires powerful cosmic ray engines able
to accelerate particles up to extreme energies, somewhat above 10^{13.6} GeV.
Using a realistic Monte Carlo simulation with the AIRES engine, we study the
main characteristics of the air showers triggered when one of these exotic
hadrons impinges on a stationary nucleon of the Earth atmosphere. We show that
R-hadron air showers present clear differences with respect to those initiated
by standard particles. We use this shower characteristics to construct
observables which may be used to distinguish long-lived gluinos at the Pierre
Auger Observatory.Comment: 13 pages revtex, 9 eps figures. A ps version with high resolution
figures is available at
http://www.hep.physics.neu.edu/staff/doqui/rhadron_highres.p
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