AION/Magis

Abstract:

The production of black holes in extra-dimensional brane-world theories can lead to detectable signals via the Hawking evaporation of the black hole to brane-localized standard model modes. We calculate, as a function of partial wave number and number of toroidally compactified extra dimensions, the leading correction to the energy spectrum of such Hawking radiation (the greybody factors) for decay into spin-1/2 fermions and spin-1 gauge fields localized on the standard model brane. We derive the associated improved differential emission rates for both types of fields. We provide both simple expressions for the leading behavior of the greybody factors in the low-energy limit [Formula Presented] and numerical evaluation of our full analytic expressions for the emission rates, valid for [Formula Presented] The full analytic expressions demonstrate that both the greybody factors and emission rates are enhanced as the number of extra dimensions increases. © 2003 The American Physical Society.

Abstract:

We report on a search for the flavor-changing neutral current decay D 0→µ+µ- in pp- collisions at √s = 1.96 TeV using 65 pb-1 of data collected by the CDF II experiment at the Fermilab Tevatron Collider. A displaced-track trigger selects long-lived D0 candidates in the D0→µ +µ- search channel, the kinematically similar D 0→П+p- channel used for normalization, the Cabibbo-favored D0K-П- channel used to optimize the selection criteria in an unbiased manner, and their charge conjugates. Finding no signal events in the D0→µ+µ- search window, we set an upper limit on the branching fraction B(D0→µ+µ-)≤2.5×10-6 (3.3×10-6) at the 90% (95%) confidence level.