Search for large extra dimensions in diphoton events at CDF
Abstract
In spite of its undisputed success, the Standard Model is not a theory of everything as it does not incorporate gravity. Gravity is the weakest of all forces and its strength becomes comparable to the remaining forces at energies of the order of the Planck scale, at approximately 10 19 GeV and the Standard Model is viewed as an effective theory at energies below this scale. Recently, a model of large extra dimensions has been formulated by Arkani-Hamed, Dimopoulous, and Dvali that claims that the electroweak scale (approximately 1 TeV) is the only fundamental scale in nature and the fact that the Planck scale appears so large is an artifact of the existence of extra dimensions in which only gravity propagates. This theory can be tested at existing collider experiments, where energies sufficiently high to probe the extra dimensions can be achieved. In particular, the existence of extra dimensions can manifest itself with production of Standard Model particles through graviton mediated processes and thus it predicts an enhancement of production cross sections at high invariant mass. The goal of this work is to search for an excess in the 100 pb-1 of diphoton data collected with the Collider Detector at Fermilab at s = 1.8 TeV during the 1992--1996 run. No excess is observed and thus we place a 95% confidence level limit on the Planck scale in the bulk extra dimensions MS of 899 GeV for constructive interference and of 797 GeV for destructive interference (Hewett convention).
- Publication:
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Ph.D. Thesis
- Pub Date:
- 2002
- Bibcode:
- 2002PhDT........99M