BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Hybrid performance of the Pierre Auger Observatory DTSTART;VALUE=DATE-TIME:20070704T153000Z DTEND;VALUE=DATE-TIME:20070704T154200Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-976@cern.ch DESCRIPTION:Speakers: Dr. DAWSON\, Bruce (University of Adelaide)\nA key f eature of the Pierre Auger Observatory is its hybrid design\, in\nwhich ul tra high energy cosmic rays are detected simultaneously by\nfluorescence t elescopes and a ground array. The two techniques see air\nshowers in compl ementary ways\, providing important crosschecks and\nmeasurement redundanc y. Much of the hybrid capability stems from the\naccurate geometrical reco nstruction it achieves\, with accuracy better than\nthe ground array count ers or a single telescope could achieve\nindependently. We have studied th e geometrical and longitudinal profile\nreconstructions of hybrid events. We present the results for the hybrid\nperformance of the Observatory\, in cluding trigger efficiency\, energy and\nangular resolution\, and the effi ciency of the event selection.\n\nhttps://indico.nucleares.unam.mx/event/4 /session/10/contribution/976 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/976 END:VEVENT BEGIN:VEVENT SUMMARY:Systematic study of atmosphere-induced influences and uncertaintie s on shower reconstruction at the Pierre Auger Observatory DTSTART;VALUE=DATE-TIME:20070704T154200Z DTEND;VALUE=DATE-TIME:20070704T155400Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-398@cern.ch DESCRIPTION:Speakers: PROUZA\, Michael (Columbia University)\nThe Pierre A uger Observatory employs a wide range of atmospheric monitoring\ninstrumen ts: two laser facilities\; elastic lidar stations\; aerosol phase\nfunctio n monitors\; a horizontal attenuation monitor\; star monitors\;\nweather s tations\; and balloon soundings. Using all available analyzed\natmospheric data we tested the impact on the shower reconstruction\, namely\non the s hower energy and the position of shower maximum (Xmax). We focused\non ide ntifying the impact of different atmospheric conditions on the\nreconstruc tion of "golden hybrid" events. These events\, which can be\nindependently reconstructed by the fluorescence detector and the surface\ndetector\, ar e of particular importance for the energy calibration. The\nresults of thi s study are given in this paper.\n\nhttps://indico.nucleares.unam.mx/event /4/session/10/contribution/398 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/398 END:VEVENT BEGIN:VEVENT SUMMARY:Reconstruction accuracy of the surface detector of the Pierre Auge r Observatory DTSTART;VALUE=DATE-TIME:20070704T155400Z DTEND;VALUE=DATE-TIME:20070704T160600Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-297@cern.ch DESCRIPTION:Speakers: Dr. MALDERA\, Simone (Univ. fo Torino)\nThe reconstr uction of extensive air showers (arrival direction\, core position and\nen ergy estimation) by the \nsurface detector (SD) of the Pierre Auger Observ atory is discussed together with the\ncorresponding accuracy.\nWe determin e the angular reconstruction accuracy as a function of the station\nmultip licity: the resolution \nobtained by the SD only is in agreement with the one obtained from hybrid events\,\ni.e.\, showers observed \nsimultaneousl y by the fluorescence and the surface detectors.\nWe discuss statistical a nd systematical uncertainties in the determination of the\ncore location a nd the signal \nat 1000 m from the core\, S(1000)\, which is used to estim ate the primary energy. The\nreconstruction method \ntakes into account th e signals of the fired stations with their uncertainties and the\nthreshol ds for the "zero" \nsignal stations. We use the lateral distribution funct ion that is fitted to the data.\n\nhttps://indico.nucleares.unam.mx/event/ 4/session/10/contribution/297 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/297 END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the UHECR Energy Spectrum using data from the Surfa ce Detector of the Pierre Auger Observatory DTSTART;VALUE=DATE-TIME:20070704T160600Z DTEND;VALUE=DATE-TIME:20070704T161800Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-313@cern.ch DESCRIPTION:Speakers: Dr. ROTH\, Markus (Forschungszentrum Karlsruhe)\nAt the southern site of the Pierre Auger Observatory\, which is close to comp letion\,\nan exposure that significantly exceeds the largest forerunner ex periments has already\nbeen accumulated. We report a measurement of the co smic ray energy spectrum based on\nthe high statistics collected by the su rface detector. The methods developed to\ndetermine the spectrum from reco nstructed observables are described. The energy\ncalibration of the observ ables\, which exploits the correlation of surface detector\ndata with fluo rescence measurements in hybrid events\, is presented in detail.\nSystemat ic uncertainties in the measured cosmic ray energy spectrum are discussed. \n\nhttps://indico.nucleares.unam.mx/event/4/session/10/contribution/313 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/313 END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the UHECR spectrum above 10^{19} eV at the Pierre A uger Observatory using showers with zenith angles greater than 60 degrees DTSTART;VALUE=DATE-TIME:20070704T161800Z DTEND;VALUE=DATE-TIME:20070704T163000Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-319@cern.ch DESCRIPTION:Speakers: Mrs. FACAL\, Pedro (Universidad de Santiago de Compo stela)\nWe report on the cosmic ray spectrum obtained using the inclined e vents detected with\nthe Pierre Auger Observatory. Showers with zenith ang les between 60$^\\circ$ and\n80$^\\circ$ recorded in the period between Ja nuary 1st\, 2004 and December 31st\, 2006\nare analysed. Showers are first reconstructed in arrival direction and then fitted to\ndensity maps of th e muon numbers obtained from $10^{19}$eV simulated proton showers\nfor dif ferent arrival directions\, to\nobtain the core position and an overall no rmalisation factor $N_{19}$ which is used\nas an energy estimator. The par ameter $N_{19}$ is shown to be correlated with the\nshower energy measured with the fluorescence technique for a sub-sample of good\nquality hybrid showers. The correlation obtained between $N_{19}$ and energy is used\nto measure the energy of all the showers.\n\nhttps://indico.nucleares.unam.mx /event/4/session/10/contribution/319 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/319 END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the cosmic ray spectrum above 10^{18} eV using data recorded with the fluorescence detectors and at least one detector of the surface array of the Auger Observatory DTSTART;VALUE=DATE-TIME:20070704T163000Z DTEND;VALUE=DATE-TIME:20070704T164200Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-316@cern.ch DESCRIPTION:Speakers: Dr. PERRONE\, Lorenzo (Universita de Lecce)\nThree y ears of data collected with the fluorescence detector in coincidence with at\nleast one station of the surface detector array ('hybrid data') are us ed to measure\nthe flux and energy spectrum of cosmic rays above about 10^ {18}eV. The hybrid\nmeasurement extends the spectrum measured with the sur face detector data alone\ntowards lower energies\, and provides a cross-ch eck in the overlap region with an\nindependent analysis method. The determ ination of the aperture of the fluorescence\ndetector and of the live-time \, which are key features of this measurement\, is\nillustrated in detail. Our estimates of the corresponding systematic uncertainties\nare given.\n \nhttps://indico.nucleares.unam.mx/event/4/session/10/contribution/316 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/316 END:VEVENT BEGIN:VEVENT SUMMARY:The UHECR spectrum measured at the Pierre Auger Observatory and it s astrophysical implications DTSTART;VALUE=DATE-TIME:20070704T164200Z DTEND;VALUE=DATE-TIME:20070704T165400Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-1-318@cern.ch DESCRIPTION:Speakers: Dr. TOKANATSU\, Yamamoto (University of Chicago)\nTh e Southern part of the Pierre Auger Observatory\, which is nearing complet ion\, has\nbeen in stable operation since January 2004 whilst it has grown in size. The large\nsample of data collected so far has led to a signific ant improvement to the energy\nspectrum of UHE cosmic rays over that previ ously reported by the Pierre Auger\nObservatory\, both in with regard to s tatistics and systematic uncertainties. In this\ncontribution we summaris e two measurements of the energy spectrum\, one based on the\nhigh-statist ics surface detector data\, and the other on the hybrid data\, where the\n precision of the fluorescence measurements is enhanced by additional infor mation from\nthe surface array. The complementarity of the two approaches is emphasised\,\nand results are compared. Possible astrophysical implica tions of our measurements\,\nand in particular the presence of spectral fe atures\, are discussed.\n\nhttps://indico.nucleares.unam.mx/event/4/sessio n/10/contribution/318 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/318 END:VEVENT BEGIN:VEVENT SUMMARY:Observation of the GZK Cutoff by the HiRes Experiment DTSTART;VALUE=DATE-TIME:20070704T133000Z DTEND;VALUE=DATE-TIME:20070704T134200Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-0-1128@cern.ch DESCRIPTION:Speakers: Prof. BERGMAN\, Douglas (Rutgers University)\nThe Hi Res Experiment has observed the GZK Cutoff. We will present power law fit s to\nthe latest HiRes monocular spectra\, and use the results of these fi ts to argue that\nthe GZK Cutoff has been definitively observed in that da taset. We will also present\nfits to a uniform sorce density model.\n\nht tps://indico.nucleares.unam.mx/event/4/session/10/contribution/1128 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/1128 END:VEVENT BEGIN:VEVENT SUMMARY:HiRes Stereo and Monocular Spectra DTSTART;VALUE=DATE-TIME:20070704T134200Z DTEND;VALUE=DATE-TIME:20070704T135400Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-0-1262@cern.ch DESCRIPTION:Speakers: Prof. SOKOLSKY\, Pierre (University of Utah)\nWe pre sent results on the ultra-high energy cosmic ray spectrum as measued\nby t he High Resolution Fly's Eye Experiment. The spectrum is analyzed in\ntwo different ways: monocular reconstruction and stereo reconstruction.\nThe m onocular spectrum has the highest statistics while the stereo\nspectrum ha s the best resolution.The monocular spectrum has a threshold of\n.1 EeV wh ile the stereo spectrum's energy threshold is near 1 EeV. Both\nspectra sh ow strong evidence of structure\, including the ankle\, near 3-5\nEeV and the GZK cutoff near 60 EeV. In particular\, the GZK cutoff has \nbeen cle arly observed at the greater than five sigma level.\n\nhttps://indico.nucl eares.unam.mx/event/4/session/10/contribution/1262 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/1262 END:VEVENT BEGIN:VEVENT SUMMARY:Cosmic Rays Composition Measurements by the HiRes Stereo DTSTART;VALUE=DATE-TIME:20070704T135400Z DTEND;VALUE=DATE-TIME:20070704T140600Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-0-1236@cern.ch DESCRIPTION:Speakers: FEDOROVA\, Yulia (University of Utah)\nThe High Reso lution Fly's Eye (HiRes) fluorescence detectors have been \ncollecting ext ensive air shower (EAS) data for more than 6 years . The \nobtained statis tics allows us to more precisely estimate the mass \ncomposition of the ul tra high energy cosmic rays (UHECR). In this study we \nsummarize the ster eo shower parameters measurements\, especially X_{max} \nmeasurements. The sensitivity limitations of our detector\, the effect of \nthe hadronic mo del choice on the estimate\, and systematic errors of our \nmeasurements a re also presented.\n\nhttps://indico.nucleares.unam.mx/event/4/session/10/ contribution/1236 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/1236 END:VEVENT BEGIN:VEVENT SUMMARY:HiRes Limits on the Tau Neutrino Flux at the Highest Energies DTSTART;VALUE=DATE-TIME:20070704T140600Z DTEND;VALUE=DATE-TIME:20070704T141800Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-0-1194@cern.ch DESCRIPTION:Speakers: Prof. MARTENS\, Kai (University of Utah)\nData from the High Resolution Fly's Eye detector that measures cosmic rays \nwith th e fluorescence technique is used to set limits on the flux of tau \nneutri nos in the energy range from 10^17 to 10^21 eV. This energy range is \npar ticularly interesting as we expect a guaranteed flux of cosmogenic \nneutr inos from the GZK mechanism.\n\nhttps://indico.nucleares.unam.mx/event/4/s ession/10/contribution/1194 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/1194 END:VEVENT BEGIN:VEVENT SUMMARY:Search for Intermediate-Scale Anisotropy by the HiRes Experiment DTSTART;VALUE=DATE-TIME:20070704T143000Z DTEND;VALUE=DATE-TIME:20070704T144200Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-0-1044@cern.ch DESCRIPTION:Speakers: Prof. THOMSON\, Gordon (Rutgers\, The State Universi ty of New Jersey\, USA)\nWe have searched for intermediate-scale anisotrop y in the data of\nthe HiRes experiment\, in particular the monocular data from the\nHiRes-II detector. These data were collected between December\, 1999\,\nand August\, 2005. We see a deficit of events near the direction of\nthe galactic anticenter\, very close to the location of the deficit\n seen by AGASA. Because of low exposure in summer months we cannot\nmake a significant test of the excess observed by the AGASA experiment\nnear the galactic center. We will describe the data\, the calculation\nof the exp ected isotropic distribution\, and the statistical\nsignificance of the ef fect.\n\nhttps://indico.nucleares.unam.mx/event/4/session/10/contribution/ 1044 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/1044 END:VEVENT BEGIN:VEVENT SUMMARY:A Measurement of the Average Longitudinal Development Profile of C osmic Ray Air Showers from 10^17eV to 10^20eV DTSTART;VALUE=DATE-TIME:20070704T144200Z DTEND;VALUE=DATE-TIME:20070704T145400Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-0-712@cern.ch DESCRIPTION:Speakers: Mr. HUGHES\, Gareth (Rutgers\, The State University of New Jersey\, USA)\nUltra High Energy Cosmic Rays (UHECRs) have an energ y many times\ngreater than that of particles accelerated in colliders. The \nExtended Air Showers (EAS) resulting from their interaction in the\natmo sphere give us the opportunity to study not only Cosmic Rays but\nalso the se extremely energetic cascades.\n\nA method to calculate the Average Long itudinal Shower profile has been\napplied to the High Resolution Fly's Eye Detector (HiRes) data. A\ncomplete detector simulation was used to throw CORSIKA (QGSJET)\nshowers which are then analyzed using the same technique . The main\nfeatures of the average showers are compared to the Monte Carl o as a\nfunction of energy. Systematic errors in the reconstruction of the \nprofile are considered.\n\nhttps://indico.nucleares.unam.mx/event/4/sess ion/10/contribution/712 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/712 END:VEVENT BEGIN:VEVENT SUMMARY:Search for correlation of UHECRs and BL Lacs in Pierre Auger Obser vatory data. DTSTART;VALUE=DATE-TIME:20070704T180500Z DTEND;VALUE=DATE-TIME:20070704T181500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-3-75@cern.ch DESCRIPTION:Speakers: Dr. HARARI\, Diego (Centro Atomico Bariloche)\nSever al analyses of the data collected by other experiments have\nfound an exce ss of cosmic rays in correlation with subclasses of \nBL Lacs. We test th ese analyses with the data from the Pierre \nAuger Observatory\, and repo rt on the results of our searches.\n\nhttps://indico.nucleares.unam.mx/eve nt/4/session/10/contribution/75 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/75 END:VEVENT BEGIN:VEVENT SUMMARY:Studies of clustering in the arrival directions of cosmic rays det ected at the Pierre Auger Observatory above 10 EeV. DTSTART;VALUE=DATE-TIME:20070704T181500Z DTEND;VALUE=DATE-TIME:20070704T182500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-3-74@cern.ch DESCRIPTION:Speakers: Dr. MOLLERACH\, Silvia (Centro Atomico Bariloche)\nT he clustering properties of the arrival directions of ultra high energy co smic \nrays encode important information to determine their origin\, compo sition\, \nand to constrain galactic and extragalactic magnetic fields. We present here \nthe results of a variety of analyses of data from the Pie rre Auger Observatory\nas a function of the angular scale and the energy t hreshold. We compare our \nresults with the signals found by previous expe riments.\n\nhttps://indico.nucleares.unam.mx/event/4/session/10/contributi on/74 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/74 END:VEVENT BEGIN:VEVENT SUMMARY:Composition-sensitive parameters measured with the surface detecto r of the Pierre Auger Observatory DTSTART;VALUE=DATE-TIME:20070704T170500Z DTEND;VALUE=DATE-TIME:20070704T171500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-2-596@cern.ch DESCRIPTION:Speakers: \nA key step towards the understanding of the origin of\nultra-high energy cosmic rays is their mass composition.\nPrimary pho tons and neutrinos produce markedly different\nshowers from nuclei\, while showers of nuclear species are\nnot easy to distinguish. To maximise the discrimination\nwith the Pierre Auger Observatory ideally all mass-sensiti ve\nobservables should be combined\, but the 10% duty cycle of\nthe fluore scence telescopes largely prevents the use of\nhybrid data\, and therefore of the depth of shower maximum\,\nfor the very highest energies.\nTherefo re\, we investigate mass-sensitive observables accessible \nwith the surfa ce detectors alone. These include \nthe signal risetime in the Cherenkov tanks\, \nthe curvature of the shower front\, \nthe asymmetry of the signa l in azimuth\, and \nvarious methods to assess the muon-to-electromagnetic ratio. \nThe mass sensitivity of these variables is demonstrated and thei r \napplication for composition studies is discussed.\n\nhttps://indico.nu cleares.unam.mx/event/4/session/10/contribution/596 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/596 END:VEVENT BEGIN:VEVENT SUMMARY:Search for ultra-high energy photons with the Pierre Auger Observa tory DTSTART;VALUE=DATE-TIME:20070704T171500Z DTEND;VALUE=DATE-TIME:20070704T172500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-2-602@cern.ch DESCRIPTION:Speakers: HEALY\, Matthew (UCLA)\nData taken at the Pierre Aug er Observatory are used to search for air\nshowers initiated by ultra-high energy (UHE) photons. \nThe results of\nsearches for UHE photons are repo rted from hybrid observations\n(fluorescence and array detectors). Additio nally\, using the larger\ndata set from the array detectors alone\, a more stringent test of\npredicted large photon fluxes is presented.\n\nhttps:/ /indico.nucleares.unam.mx/event/4/session/10/contribution/602 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/602 END:VEVENT BEGIN:VEVENT SUMMARY:Study of the cosmic ray composition above 0.2 EeV using the longit udinal profiles of showers observed at the Pierre Auger Observatory DTSTART;VALUE=DATE-TIME:20070704T172500Z DTEND;VALUE=DATE-TIME:20070704T173500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-2-594@cern.ch DESCRIPTION:Speakers: Dr. UNGER\, Michael (Forschungszentrum Karlsruhe)\nT he Pierre Auger Observatory has been collecting data in a stable\n manner since January 2004. We present here a study of the cosmic ray\n composit ion using events recorded in hybrid mode during the first\n three years o f data taking. These are air showers observed by the\n fluorescence dete ctor as well as the surface detector\, so the depth\n of shower maximum ( Xmax) is measured directly. The cosmic ray\n composition is studied in d ifferent energy ranges by comparing the\n observed Xmax distribution with predictions from air shower\n simulations for different nuclei. The cha nge of with energy\n (elongation rate) is used to derive estimates of th e change in\n primary composition. We also investigate the width of the\ n Xmax distribution as an additional mass-sensitive observable.\n\nhttps: //indico.nucleares.unam.mx/event/4/session/10/contribution/594 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/594 END:VEVENT BEGIN:VEVENT SUMMARY:Test of hadronic interaction models with data from the Pierre Auge r Observatory DTSTART;VALUE=DATE-TIME:20070704T173500Z DTEND;VALUE=DATE-TIME:20070704T174500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-2-605@cern.ch DESCRIPTION:Speakers: Dr. ENGEL\, Ralph (Forschungszentrum Karlsruhe)\nThe Pierre Auger Observatory allows the measurement of both\nlongitudinal pro files and lateral particle distributions of high\nenergy showers. The form er trace the overall shower development\,\nmainly of the electromagnetic c omponent close to the core\, and the\nlatter reflect the particle densitie s in the tail of the shower far\naway from the core\, and are sensitive to both the muonic and\nelectromagnetic components. Combining the two comple mentary\nmeasurements\, predictions of air shower simulations are tested. In\nparticular the muon component of the tank signals\, which is sensitive \nto hadronic interactions at high energy\, is studied with several\nindep endent methods. Implications for the simulation of hadronic\ninteractions at ultra-high energy are discussed.\n\nhttps://indico.nucleares.unam.mx/ev ent/4/session/10/contribution/605 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/605 END:VEVENT BEGIN:VEVENT SUMMARY:Status and Prospect of Telescope Array (TA) Experiment DTSTART;VALUE=DATE-TIME:20070707T170500Z DTEND;VALUE=DATE-TIME:20070707T171700Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-955@cern.ch DESCRIPTION:Speakers: FUKUSHIMA\, Masaki (Institute for Cosmic Ray Researc h\, University of Tokyo\, Kashiwa\, Japan)\nThe Telescope Array (TA) is a hybrid experiment of an air shower array\nand fluorescence telescopes inst alled in Utah\, USA. It aims at\ndrawing a conclusion on the (non-)existen ce of the GZK cutoff\nreported controversially by the AGASA and HiRes expe riments. An\nanisotropy of the UHECR arrival directions will be studied in \nthe northern hemisphere where the galactic disturbances are\nsmall. The use of plastic scintillator is advantageous for the\ndetermination of the air shower energy independent of the\nhadronic interaction model and the p rimary composition of the\nshower. Various calibration and monitoring meth ods have been\ndeveloped for the accurate determination of the air fluores cence\nenergy scale. It has a total acceptance more than 10 times\nlarger than that of AGASA and is expected to start taking data\nin spring 2007. T he status of the experiment is reported and\nprospects for physics are giv en.\n\nhttps://indico.nucleares.unam.mx/event/4/session/10/contribution/95 5 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/955 END:VEVENT BEGIN:VEVENT SUMMARY:Observation of ultra high energy cosmic rays with the surface dete ctor array of the TA experiment DTSTART;VALUE=DATE-TIME:20070707T171700Z DTEND;VALUE=DATE-TIME:20070707T172900Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-968@cern.ch DESCRIPTION:Speakers: Dr. SAGAWA\, Hiroyuki (Institute for Cosmic Ray Rese arch\, University of Tokyo)\nThe Telescope Array (TA) experiment is an arr ay of surface detectors \nsurrounded by three stations of fluorescence tel escopes in Utah\, USA\, to \ninvestigate the origin of the highest energy cosmic rays of energy beyond 10^\n{20}eV. We deployed about 500 plastic sc intillation counters on a grid with 1.2 \nkm spacing as a surface array by March 2007. Each surface detector is outfitted \nwith double layer scinti llators of 3m^2 area\, readout electronics\, and wireless \nLAN communicat ion system\, which are powered by solar system. Here we \npresent the per formance of the surface detector array and the status and the \nprospect o f observation of air shower events.\n\nhttps://indico.nucleares.unam.mx/ev ent/4/session/10/contribution/968 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/968 END:VEVENT BEGIN:VEVENT SUMMARY:The First Observation with the Fluorescence Detectors of the Teles cope Array Experiment DTSTART;VALUE=DATE-TIME:20070707T172900Z DTEND;VALUE=DATE-TIME:20070707T174100Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-847@cern.ch DESCRIPTION:Speakers: Dr. OGIO\, Shoichi (Department of Physics\, Osaka Ci ty University)\nThe fluorescence measurement is the key in observations of ultra high energy cosmic\nrays and in determinations of their primary ene rgies in the TA experiment. All the\nfluorescence detectors of TA will be in operation from June 2007. In this talk\, we\nwill present the character istics of the telescopes and the status of the associated\nsystems includi ng for the atmospheric monitoring and the PMT calibrations. We will\nalso present preliminary results from the first observation run with the full\n telescope configurations.\n\nhttps://indico.nucleares.unam.mx/event/4/sess ion/10/contribution/847 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/847 END:VEVENT BEGIN:VEVENT SUMMARY:Telescope Array Aperture: Mono\, Stereo and Hybrid DTSTART;VALUE=DATE-TIME:20070707T174100Z DTEND;VALUE=DATE-TIME:20070707T175300Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-820@cern.ch DESCRIPTION:Speakers: Dr. TSUNESADA\, Yoshiki (Tokyo Institute of Technolo gy)\nWe have developed detector simulators for the TA fluorescence telesco pes (FD) \nand the surface particle detector array. In this paper we descr ibe a new \nmethod to evaluate the TA-FD aperture with a Monte-Carlo techn ique. Since the \nfield of view and the effective area for the FDs are qui te large\, a considerable \nCPU cost is required for air shower simulation s in the full observable region. In \norder to reduce CPU time\, we employ an efficient simulation method for the \naperture calculation. The basic assumption in this method is that each TA-FD \nstation is comprised of 12 telescopes of identical characteristics. Therefore it is \npossible to ca lculate the triggering functions of a whole station for a given \nshower event by building up the single telescope triggering function with an \nap propriate superposition scheme. We have developed this method to calculate \nthe FD aperture for various detector configurations\, as monocular and stereo \nobservations with a vetoed telescope\, and hybrid observations wi th the surface \ndetector array. We also discuss expected results and astr ophysical significance \nfrom the TA first year observation.\n\nhttps://in dico.nucleares.unam.mx/event/4/session/10/contribution/820 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/820 END:VEVENT BEGIN:VEVENT SUMMARY:First results on UHE Neutrinos from the NuMoon experiment DTSTART;VALUE=DATE-TIME:20070707T175300Z DTEND;VALUE=DATE-TIME:20070707T180500Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-63@cern.ch DESCRIPTION:Speakers: SCHOLTEN\, Olaf (KVI / RUG)\nWhen high-energy cosmic rays impinge on a dense dielectric medium\, radio waves\nare produced thr ough the Askaryan effect. At wavelengths comparable to the\ntypical longit udinal size of showers produced by Ultra-High Energy cosmic rays\nor neutr inos\, radio signals are an extremely efficient way to detect these\nparti cles [1]. These can be detected using the Westerbork Synthesis Radio\nTele scope (WSRT) which consists of fourteen 25m parabolic dishes. The low\nfre quency band which concerns us here covers 115-170MHz. In tied-array mode t he\nsystem noise at low frequencies is F_n=600Jy. To observe radio bursts of short\nduration\, the new pulsar backend (PuMa II) is used. It provides \ndual-polarization baseband sampling of eight 20MHz bands. In the used\nc onfiguration\, four frequency bands will observe the same part of the moon with\nthe remaining four a different section.\n\nA first analysis of the present 100 hour observations at the WSRT will be\npresented.\n\n O.~Schol ten etal\, Astropart. Phys. 26(2006)219.\n\nhttps://indico.nucleares.unam. mx/event/4/session/10/contribution/63 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/63 END:VEVENT BEGIN:VEVENT SUMMARY:A search for clusters in arrival directions of UHECRs observed by the Yakutsk array DTSTART;VALUE=DATE-TIME:20070707T180500Z DTEND;VALUE=DATE-TIME:20070707T181700Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-247@cern.ch DESCRIPTION:Speakers: Dr. IVANOV\, Anatoly (Institute for Cosmophysical Re search & Aeronomy\, Yakutsk 677980\, Russia)\nThere are some prerequisites to possible success in searching for small-scale \nanisotropy of cosmic r ay arrival directions at the highest energies. Recent claims \nof autocorr elations in the data of giant extensive air shower (EAS) arrays and \npres umable correlations between BL Lacertae and ultra-high energy cosmic \nray s (UHECRs) incite to sift the Yakutsk array data. Present analysis is base d on \ndata recorded between 1974 and 2004\, with a total of 1674 showers selected \nwith energies from 5*10^18 to 10^20 eV\, zenith angles below 60 degrees and \naxes within array area.\n\nhttps://indico.nucleares.unam.mx /event/4/session/10/contribution/247 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/247 END:VEVENT BEGIN:VEVENT SUMMARY:Extensive Air Showers of Cosmic Rays Without Muon Component DTSTART;VALUE=DATE-TIME:20070707T181700Z DTEND;VALUE=DATE-TIME:20070707T182900Z DTSTAMP;VALUE=DATE-TIME:20260813T003006Z UID:indico-contribution-10-4-413@cern.ch DESCRIPTION:Speakers: Dr. MIKHAILOV\, Alexei (Institute of Cosmophysical R esearch and Aeronomy)\nExtensive air showers of cosmic rays ultra-high ene rgy without muon \ncomponent registered by the Yakutsk array have been ana lysed. Among them \nwe found some clusters and these clusters correlate w ith pulsars. The problem \nof origin showers without muons and the chemica l composition of cosmic rays \nare discussed.\n\nhttps://indico.nucleares. unam.mx/event/4/session/10/contribution/413 LOCATION:Merida\, Mexico Yucatan II+III+IV (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/10/contribution/413 END:VEVENT END:VCALENDAR