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Release : 2010
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Book Synopsis Search for Randall-Sundrum Gravitons in Dielectron and Diphoton Final States with 5.4fb-1 of D0 Data by :
Download or read book Search for Randall-Sundrum Gravitons in Dielectron and Diphoton Final States with 5.4fb-1 of D0 Data written by . This book was released on 2010. Available in PDF, EPUB and Kindle. Book excerpt: A search for the lightest Kaluza-Klein mode of the graviton in the Randall-Sundrum model with a warped extra dimension is performed in the dielectron and diphoton channels. The data set used for the search corresponds to 5.4 fb−1 of data from p{bar p} collisions at a center-of-mass energy of 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron between July 2002 and Summer 2009. We search for resonances in the invariant mass spectrum of two electromagnetic showers from the decay of the graviton to either electron-positron pairs or photon pairs. To optimize the sensitivity, the dielectron and diphoton channels are analyzed separately, then the results are combined together in the end. We also investigate whether, due to the unique spin-2 nature of the graviton, the angular distribution of the final state particles can be used to significantly enhance the sensitivity of the search. We set 95% confidence level upper limits on the graviton production cross section times branching fraction into electron-positron pairs of between (almost equal to) 7 fb and (almost equal to) 0.5 fb for a range of graviton masses from 220 GeV and 1050 GeV, respectively. Compared with Randall-Sundrum model predictions, these results correspond to lower limits on the lightest graviton mass between 440 GeV and 1040 GeV, for the dimensionless graviton coupling to the Standard Model fields k/{bar M}{sub Pl} in the range from 0.01 to 0.1. In addition, for coupling k/{bar M}{sub Pl} of 0.01, gravitons with masses between 460 GeV and 560 GeV are also excluded at 95% confidence level. These results represent the most sensitive limits to date.