2,689 research outputs found

    Tau neutrino search with Cherenkov telescopes

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    Cherenkov telescopes could have the capability of detecting high energy tau neutrinos by searching for very inclined showers. If a tau lepton, produced by a tau neutrino, escapes from the Earth crust, it will decay and initiate an air shower which can be detected by a fluorescence/Cherenkov telescope. Here we present a detailed Monte Carlo simulation of event rates induced by tau neutrinos in the energy range from 1 PeV to 1 EeV. Topographic conditions are taken into account for a set of example locations. As expected, we find a neutrino sensitivity which depends on the shape of the energy spectrum from astrophysical sources. We compare our findings with the sensitivity of the dedicated IceCube neutrino telescope under different conditions. We also find that a difference of several factors can be observed depending on the topographic conditions of the sites sampled.Comment: Proceedings of 33nd International Cosmic Ray Conference - 2013 - Rio de Janeiro, Brazi

    The Quest for Pension Reform: Poland's Security though Diversity

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    All over the world, pension systems have financing difficulties that need to be addressed. There are three ways of dealing with pension systems problems, namely subsidisation, rationalisation and reforming. Opposite to the first two, the latter one means a deep change of system fundamentals. The new system is a way of income allocation over life cycle. The system is entirely based on individual accounts. Individuals have two accounts each. At the day of retirement amounts accumulated in each of the accounts are annualised. Pensions depend on two factors: (a) accumulated capital, and (b) age of retirement. Such old-age pension system provides its participants with high security thanks to diversification of risk between two markets, namely the labour market and the capital market, and full link between contributions and benefits. Minimum guarantee is financed by the state budget. The new system is less exposed to typical problems of that markets. Additionally, it is more resistant to political pressures. Additionally, the new system is expected to create the following externalities: change of savings structure in favour of long term savings, less incentive for early retirement, and less incentive for hiding income. The old Polish old-age system was terminated on 31 December 1998 - a new one called "Security through Diversity" was introduced on 1 January 1999. The new system covers people up to 50. The most important feature of the new system is its separation within social security. In particular, a separate contribution is paid for old-age. One part (5/8) of that contribution goes to a notional defined contribution 1st pillar individual account, the other part (3/8) goes to fully funded 2nd pillar individual account. Both elements of the system work along defined contribution regime. People between 30 and 50 have an option to pay entire contribution to 1st pillar individual account, people below 30 have their old age contributions automatically divided between the accounts.http://deepblue.lib.umich.edu/bitstream/2027.42/39670/3/wp286.pd
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