Z boson pair production at the LHC to O(αs){\cal O}(\alpha_s) in TeV scale gravity models

The first results on next-to-leading order QCD corrections to the production of two Z bosons, in hadronic collisions in the large extra dimension ADD model are presented. Various kinematical distributions are obtained to order $\alpha_s$ in QCD by taking into account all the parton level subprocesses. We estimate the impact of the QCD corrections on various observables and find that they are significant. We also show the reduction in factorisation scale uncertainity when ${\cal O}(\alpha_s)$ effects are included.Comment: Latest version; coincides with the version published in Nucl. Phys.

Next-to-leading order QCD corrections to the ZZ boson pair production at the LHC in Randall Sundrum model

The first results on next-to-leading order QCD corrections to production of two $Z$ bosons in hadronic collisions in the extra dimension model of Randall and Sundrum are presented. Various kinematical distributions are obtained to order $\alpha_s$ in QCD by taking into account all the parton level subprocesses. We estimate the impact of the QCD corrections on various observables and find that they are significant. We also show the reduction in factorization scale uncertainty when ${\cal O}(\alpha_s)$ effects are included.Comment: 18 pages, 8 figure

Next-to-leading order QCD corrections to W+W−W^+W^- production at the LHC in Randall Sundrum model

We present next-to-leading order QCD corrections to production of two $W$ bosons at the LHC in the Randall-Sundrum model. Various kinematical distributions are obtained to order $\alpha_s$ in QCD by taking into account all the parton level subprocesses. We estimate the impact of the QCD corrections on various observables and find that they are significant. We also show the reduction in factorization scale uncertainty when ${\cal O}(\alpha_s)$ effects are included.Comment: 16 pages, 5 figure

Direct Signals for Large Extra Dimensions in the Production of Fermion Pairs at Linear Colliders

We analyze the potentiality of the new generation of $e^+e^-$ linear colliders to search for large extra dimensions via the production of fermion pairs in association with Kaluza-Klein gravitons (G), i.e. $e^+e^- \leftarrow f\bar{f}G$. This process leads to a final state exhibiting a significant amount of missing energy in addition to acoplanar lepton or jet pairs. We study in detail this reaction using full tree level contibutions due to the graviton emission and the standard model backgrounds. After choosing the cuts to enhance the signal, we show that a linear collider with a center-of-mass energy of 500 GeV will be able to probe quantum gravity scales from 0.96(0.86) up to 4.1(3.3) TeV at 2(5)$\sigma$ level, depending on the number of extra dimensions.Comment: 19 pages, 5 figures. Using RevTex, axodraw.sty. Discussion was extended. No changes in the results. Accepted for publication by Phys. Rev.

Search for large extra dimensions in dimuon and dielectron events in pp collisions at s=7\sqrt{s} = 7 TeV

Results are presented from a search for large, extra spatial dimensions in events with either two isolated muons or two isolated electrons. The data are from proton-proton interactions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The size of the data sample corresponds to an integrated luminosity of approximately 2 inverse femtobarns. The observed dimuon and dielectron mass spectra are found to be consistent with standard-model expectations. Depending on the number of extra dimensions, the 95% confidence level limits from the combined dimuon and dielectron channels range from Ms > 2.4 TeV to Ms > 3.8 TeV, where Ms characterizes the scale for the onset of quantum gravity.Comment: Submitted to Physics Letters