In the Randall-Sundrum (RS) scenario the compactification radius of the extra dimension is stabilized by the radion, which is a scalar field lighter than the graviton Kaluza-Klein states. It implies that the detection of the radion will be the first signature of the stabilized RS model. In this paper we study the exclusive production of the radion in electromagnetic and diffractive hadron - hadron collisions at the LHC. Our results demonstrate that the diffractive production of radion is dominant and should be feasible of study at CERN LHC.Comment: 6 pages, 3 figures, 1 tabl

The double vector meson production in two photon collisions is addressed assuming that the color singlet t-channel exchange carries large momentum transfer. We consider the non-forward solution of the BFKL equation at high energy and large momentum transfer and estimate the total and differential cross section for the process γγ → V1V2, where V1 and V2 can be any two vector mesons (Vi = ρ, ω, φ, J/Ψ, Υ). A comparison between our predictions and previous theoretical results obtained at Born level or assuming the Pomeron-exchange factorization relations is presented. Our results demonstrate that the BFKL dynamics implies an enhancement of the cross sections. Predictions for the future linear colliders (TESLA, CLIC and ILC) are given.

The exclusive production by the photon fusion of magnetic monopoles and the bound states of magnetic monopoles, the monopolium, is consider in different high energy processes. More specifically, we calculate the total cross sections of the ultraperipheral elastic collisions of electronelectron, proton-proton and lead-lead in present and future colliders, comparing with the previous results found in the literature. Our results indicates that magnetic monopoles or his bound states, if both exists, can be measuareble in future electron-electron colliders.

The meson production cross sections are estimated considering photon-photon interactions in hadron -hadron collisions at CERN LHC energies. We consider a large number of mesons with photon-photon partial decay width well constrained by the experiment and some mesons which are currently considered as hadronic molecule and glueball candidates. Our results demonstrate that the experimental analysis of these states is feasible at CERN -LHC. PACS numbers: 12.40.Nn, 13.85.Ni, 13.85.Qk, 13.87.Ce The Large Hadron Collider (LHC) at CERN started high energy collisions two years ago. During this period a large amount of data have been collected considering pp collisions at √ s = 0.9, 2.36 and 7 TeV as well as P bP b collisions at √ s = 2.76 TeV. Currently, there is a great expectation that LHC will discover new physics beyond the Standard Model, such as supersymmetry or extra dimensions. However, we should remember that the LHC opens a new kinematical regime at high energy, where several questions related to the description of the Quantum Chromodynamics (QCD) remain without satisfactory answers. Some open questions are the search for non-qq resonances, the determination of the spectrum of qq states and the identification of states with anomalous γγ couplings. A possible way to study these problems is the study of meson production in two-photon interactions [1,2]. In general, this process is studied in leptonic colliders. An alternative is to use ultra-relativistic protons and nuclei, which give rise to strong electromagnetic fields and estimate the production of a given final state considering the photon -photon and photon -hadron interactions. In particular, it is possible to study photon -photon interactions in proton -proton and nucleusnucleus collisions at LHC (For a review see Ref. [3]). Recently, Bertulani [4] revisited this subject and proposed the study of the meson production in ultraperipheral heavy ion collisions at LHC in order to constrain the two-photon decay widths. In this letter we extend this previous study for the meson production in two-photon interactions in proton -proton collisions. Initially we calculate the cross sections for mesons with photon-photon partial decay width well constrained by the experiment, which allows to constrain the theoretical methods and calibrates the experimental techniques. After we predict the cross sections for mesons which are currently considered as glueball and hadronic molecule candidates. Our results shows that LHC can be used to investigate these states.Lets consider the hadron-hadron interaction at large impact parameter (b > R h1 + R h2 ) and at ultra relativistic energies (For recent reviews see, e.g., Ref.[5]). In this regime we expect the electromagnetic interaction to be dominant. In heavy ion colliders, the heavy nuclei give rise to strong electromagnetic fields due to the coherent action of all protons in the nucleus, which can interact with each other. In a similar way, it also occurs when considering ultra relativistic protons in pp(p) colliders. The pho...

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