247 research outputs found
Absolute Fluorescence Spectrum and Yield Measurements for a wide range of experimental conditions
For the JEM-EUSO CollaborationThe fluorescence yield is a key ingredient in cosmic ray energy determination. It is sensitive to pressure, temperature and humidity. Up to now the fluorescence yield of the brightest line at 337 nm has been measured in an absolute way in one set of conditions, whereas fluorescence yields at the other wavelengths have been relatively measured for different conditions. Thus, absolute calibration for all the lines is unclear. We will do all measurements at once using the same apparatus: all the lines will be measured absolutely and not relatively for all conditions. For that we will use the 3-5 MeV electron beam of the PHIL accelerator (Photon Injector at LAL), shooting in a box filled with air at varying pressures, temperatures and humidity. Delta rays resulting from the beam collisions with Nitrogen are responsible for the light yield. The light detection probability should be independent of its emission point especially at the delta ray stopping point. The idea is to use an integrating sphere, encapsulated in a vessel where pressure, temperature and humidity can be varied. This sphere will have two ports for the beam (in and out), one more port dedicated to a NIST photodiode for calibration and another port feeding optical fibers going to: A) a grating spectrometer equipped with cooled CCD. B) a photomultiplier with BG3 filters to measure directly the integrated yield. Calibrations at the percent level, will give each line spectrum yields with a precision between 2 to 5%. A special issue will be to estimate the leakage due to "high energy" delta rays. Thus, we the air density will be increased, the beam energy will be lowered until the beam stops inside the sphere. Then, the energy loss will be precisely derived from the Bethe-Bloch formula. We will present the set-up
Antimatter and Matter Production in Heavy Ion Collisions at CERN (The NEWMASS Experiment NA52)
Besides the dedicated search for strangelets NA52 measures light
(anti)particle and (anti)nuclei production over a wide range of rapidity.
Compared to previous runs the statistics has been increased in the 1998 run by
more than one order of magnitude for negatively charged objects at different
spectrometer rigidities. Together with previous data taking at a rigidity of
-20 GeV/c we obtained 10^6 antiprotons 10^3 antideuterons and two antihelium3
without centrality requirements. We measured nuclei and antinuclei
(p,d,antiprotons, antideuterons) near midrapidity covering an impact parameter
range of b=2-12 fm. Our results strongly indicate that nuclei and antinuclei
are mainly produced via the coalescence mechanism. However the centrality
dependence of the antibaryon to baryon ratios show that antibaryons are
diminished due to annihilation and breakup reactions in the hadron dense
environment. The volume of the particle source extracted from coalescence
models agrees with results from pion interferometry for an expanding source.
The chemical and thermal freeze-out of nuclei and antinuclei appear to coincide
with each other and with the thermal freeze-out of hadrons.Comment: 12 pages, 8 figures, to appear in the proceedings of the conference
on 'Fundamental Issues in Elementary Matter' Bad Honnef, Germany, Sept.
25-29, 200
Progress on a spherical TPC for low energy neutrino detection
The new concept of the spherical TPC aims at relatively large target masses
with low threshold and background, keeping an extremely simple and robust
operation. Such a device would open the way to detect the neutrino-nucleus
interaction, which, although a standard process, remains undetected due to the
low energy of the neutrino-induced nuclear recoils. The progress in the
development of the fist 1 m prototype at Saclay is presented. Other physics
goals of such a device could include supernova detection, low energy neutrino
oscillations and study of non-standard properties of the neutrino, among
others.Comment: 3 pages, talk given at the 9th Workshop on Topics in Astroparticle
and Underground Physics, Zaragoza, September 10-1
Detecting ultra-high energy cosmic rays from space with unprecedented acceptance: objectives and design of the JEM-EUSO mission
The Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO) of the Interna- tional Space Station (ISS) is the first mission that will study from space Ultra High-Energy Cosmic Rays (UHECR). JEM-EUSO will observe Extensive Air Showers (EAS) pro- duced by UHECRs traversing the Earth's atmosphere from above. For each event, the detector will make accurate mea- surements of the energy, arrival direction and nature of the primary particle using a target volume far greater than what is achievable from ground. The corresponding increase in statistics will help to clarify the origin and sources of UHE- CRs as well as the environment traversed during production and propagation. Possibly this will bring new light onto par- ticle physics mechanisms operating at energies well beyond those achievable by man-made accelerators. The spectrum of scientific goals of the JEM-EUSO mission includes as ex- ploratory objectives the detection of high-energy gamma ray
The JEM-EUSO Instruments
For the JEM-EUSO CollaborationJEM-EUSO mission with a large and wide-angle telescope to be mounted on the International Space Station has been planned to open up "particle astronomy" through the investigation of extreme-energy cosmic rays by detecting fluorescence and Cherenkov photons generated by air showers in the earth's atmosphere. The JEM-EUSO telescope consists of 3 light-weight optical Fresnel lenses with a diameter of about 2.5m, 300k channels of MAPMTs, front-end readout electronics, trigger electronics, and system electronics. An infrared camera and a LIDAR system will be also used to monitor the earth's atmosphere. Status of the JEM-EUSO instruments will be reported
Global Description of EUSO-Balloon Instrument
For the JEM-EUSO CollaborationThe EUSO-Balloon is a pathfinder of the JEM-EUSO mission, designed to be installed on-board the International Space Station before the end of this decade. The EUSO-Balloon instrument, conceived as a scaleddown version of the main mission, is currently developed as a payload of a stratospheric balloon operated by CNES, and will, most likely, be launched during the CNES flight campaign in 2014. Several key elements of JEM-EUSO have been implemented in the EUSO-Balloon. The instrument consists of an UV telescope, made of three Fresnel lenses, designed to focus the signal of the UV tracks, generated by highly energetic cosmic rays propagating in the earth's atmosphere, onto a finely pixelized UV camera. In this contribution, we review the main stages of the signal processing of the EUSO-Balloon instrument: the photodetection, the analog electronics, the trigger stages, which select events while rejecting random background, the acquisition system performing data storage and the monitoring, which allows the instrument control during operation
The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines
The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of
kton liquid double phase TPC complemented by a magnetised iron
calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km
from CERN. The conventional neutrino beam is produced by 400 GeV protons
accelerated at the SPS accelerator delivering 700 kW of power. The long
baseline provides a unique opportunity to study neutrino flavour oscillations
over their 1st and 2nd oscillation maxima exploring the behaviour, and
distinguishing effects arising from and matter. In this paper we
show how this comprehensive physics case can be further enhanced and
complemented if a neutrino beam produced at the Protvino IHEP accelerator
complex, at a distance of 1160 km, and with modest power of 450 kW is aimed
towards the same far detectors. We show that the coupling of two independent
sub-MW conventional neutrino and antineutrino beams at different baselines from
CERN and Protvino will allow to measure CP violation in the leptonic sector at
a confidence level of at least for 50\% of the true values of
with a 20 kton detector. With a far detector of 70 kton, the
combination allows a sensitivity for 75\% of the true values of
after 10 years of running. Running two independent neutrino
beams, each at a power below 1 MW, is more within today's state of the art than
the long-term operation of a new single high-energy multi-MW facility, which
has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure
Simulations studies for the Mini-EUSO detector
Mini-EUSO is a mission of the JEM-EUSO program flying onboard the
International Space Station since August 2019. Since the first data acquisition
in October 2019, more than 35 sessions have been performed for a total of 52
hours of observations. The detector has been observing Earth at night-time in
the UV range and detected a wide variety of transient sources all of which have
been modelled through Monte Carlo simulations. Mini-EUSO is also capable of
detecting meteors and potentially space debris and we performed simulations for
such events to estimate their impact on future missions for cosmic ray science
from space. We show here examples of the simulation work done in this framework
to analyse the Mini-EUSO data. The expected response of Mini-EUSO with respect
to ultra high energy cosmic ray showers has been studied. The efficiency curve
of Mini-EUSO as a function of primary energy has been estimated and the energy
threshold for Cosmic Rays has been placed to be above 10^{21} eV. We compared
the morphology of several transient events detected during the mission with
cosmic ray simulations and excluded that they can be due to cosmic ray showers.
To validate the energy threshold of the detector, a system of ground based
flashers is being used for end-to-end calibration purposes. We therefore
implemented a parameterisation of such flashers into the JEM-EUSO simulation
framework and studied the response of the detector with respect to such
sources
Effects of charged Higgs bosons in the deep inelastic process \nu_{\tau} {\cal N} \to \tau^- X and the possibility of detecting tau-neutrinos at cosmic neutrino detectors
We study the deep inelastic process
(with an isoscalar nucleon), in the context of the
two Higgs doublet model type II (2HDM(II)). We discuss the contribution to the
total cross section of diagrams, in which a charged Higgs boson is exchanged.
We present results which show the strong dependence of such contribution on
and . We show that in the region and 90 GeV 600 GeV with the additional
experimental constraint on the involved model parameters GeV, the contribution of the charged Higgs boson exchange
diagrams to the cross section of the charged current inclusive collision can become important. We obtain that this contribution for
an inclusive dispersion generated through the collision of an ultrahigh energy
tau-neutrino with eV on a target nucleon can be
larger than the value of the contribution of the exchange diagrams,
provided that GeV and . Such
enhancement and the induced variation on the mean inelasticity
could lead to sizeable effects in the acceptance of cosmic tau-neutrino
detectors at experiments such as HiRes, PAO, and the CRTNT, which are anchored
to the ground, and at experiments such as EUSO and OWL, which are proposed to
orbit around the Earth.Comment: 18 pages, 2 figures, 8 table
Mini-EUSO experiment to study UV emission of terrestrial and astrophysical origin onboard of the International Space Station
International audienceMini-EUSO will observe the Earth in the UV range (300 - 400 nm) offering the opportunity to study a variety of atmospheric events such as Transient LuminousEvents (TLEs), meteors and marine bioluminescence. Furthermore it aims to search for Ultra High Energy Cosmic Rays (UHECR) above eV and Strange Quark Matter (SQM).The detector is expected to be launched to the International Space Station in August 2019 and look at the Earth in nadir mode from the UV-transparent window of the Zvezda module of the International Space Station. The instrument comprises a compact telescope with a large field of view (), based on an optical system employing two Fresnel lenses for lightcollection. The light is focused onto an array of 36 multi-anode photomultiplier tubes (MAPMT), for a total of 2304 pixels and the resulting signal is converted into digital, processed and stored viathe electronics subsystems on-board. In addition to the main detector, Mini-EUSO contains two ancillary cameras for complementary measurements in the near infrared (1500 - 1600 nm) and visible (400 - 780 nm) range and also a SiPM imaging array
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