Anisotropy of Primary Cosmic Rays Newt Ganugapati for IJC

Anisotropy of Cosmic Ray Induced Muons Anisotropy due to uneven distribution of cosmic ray Sources and process of CR propagation in the Milky way Modulations due to the heliosphere, solar wind ,magnetic fields Galactic effects (density gradients of CR density) Compton getting effect (relative motion of solar system with local CR plasma, Earths orbital motion around the sun) Two cones of excess and deficit because of magnetic mirroring effects due to the boundary between inner and outer galaxy Deflected by GMF and are randomized by millions of years of travel

Tibet-III Air Shower Array Scintillation Counters. 555.9 live days of HD array and 1318.9 live days of III array. Four fold coincidence recording more than 0.8 particles in charge. Air shower core positions is located in the array and zenith angle of arrival direction<40 degrees. Has a modal energy if 3TeV and a 0.9 degree angular resolution from Monte Carlo. 37 billion CR events were used Lacking the absolute detector efficiency calibration in the declination direction absolute CR intensities along Dec cannot be compared. Average intensity in each Dec belt normalized to unity. Modulation is cosmic ray intensity studied for different Dec.

Celestial CR intensity map I and II denote tail-in and loss-cone component while III denotes Cygnus region. HEGRA discovered a TeV gamma ray source there. We cannot tell the attribute hence interpretation that gamma ray emission is responsible for excesses cannot be ruled out. The years denote Solar Maxima and Minima (Magnetic activity) New excess component with a 0.1% increase in this region at a significance level of 13.3SD with a 5o pixel radius

Local Solar Time CR Intensity Map High multiplicity events with coincident detector numbers greater than 8 were adopted. The observed dipole anisotropy agrees very well with the expected CG effect Of Earth’s orbital motion Around the sun. Heliospheric Magnetic field and solar activity don’t influence the multi-TeV CR anisotropy

Celestial CR intensity for different CR energies CR Energies of 4,6.2,12,50,300 TeV respectively. Little dependency on Energy below 12 TeV and fades away after that. Tail in component visible after 50TeV Multi-TeV GCR’s whose with large gyroradii are not affected by heliospheric magnetic field it is clear GMF must be responsible for both tail-in and loss cone modulations

Can we do better?

Track Type Plots Measured RA( direct walk) for a declination band of 55o-65o

Direct-Walk sky-maps Significance in equatorial coordinates,10o*10o bins smoothed

Summary and Conclusions Initial studies indicate that AMANDA is sensitive to anisotropies of the primary cosmic rays The effects observed by Super-K should be clearly observable. AMANDA could be able to measure this with a largely improved significance due to 80X larger statistics and smaller systematic uncertainties An proper analysis would require reconstruction of all down-going events (JAMS or LLH), unfolding of seasonal effects, flare checking and improved data selection