Looking for magnetic monopoles at LHC with diphoton events

Magnetic monopoles have been a subject of interest since Dirac established the relation between the existence of monopoles and charge quantization. The intense experimental search carried thus far has not met with success. The Large Hadron Collider is reaching energies never achieved before allowing the search for exotic particles in the TeV mass range. In a continuing effort to discover these rare particles we propose here other ways to detect them. We study the observability of monopoles and monopolium, a monopole-antimonopole bound state, at the Large Hadron Collider in the $\gamma \gamma$ channel for monopole masses in the range 500-1000 GeV. We conclude that LHC is an ideal machine to discover monopoles with masses below 1 TeV at present running energies and with 5 fb$^{-1}$ of integrated luminosity.Comment: This manuscript contains information appeared in Looking for magnetic monopoles at LHC, arXiv:1104.0218 [hep-ph] and Monopolium detection at the LHC.,arXiv:1107.3684 [hep-ph] by the same authors, rewritten for joint publication in The European Physica Journal Plus. 26 pages, 22 figure

Monopolium production from photon fusion at the Large Hadron Collider

Magnetic monopoles have attracted the attention of physicists since the founding of the electromagnetic theory. Their search has been a constant endeavor which was intensified when Dirac established the relation between the existence of monopoles and charge quantization. However, these searches have been unsuccessful. We have recently proposed that monopolium, a monopole-antimonopole bound state, so strongly bound that it has a relatively small mass, could be easier to find and become an indirect but clear signature for the existence of magnetic monopoles. In here we extend our previous analysis for its production to two photon fusion at LHC energies

H2 in the interstitial channels of nanotube bundles

The equation of state of H2 adsorbed in the interstitial channels of a carbon nanotube bundle has been calculated using the diffusion Monte Carlo method. The possibility of a lattice dilation, induced by H2 adsorption, has been analyzed by modeling the cohesion energy of the bundle. The influence of factors like the interatomic potentials, the nanotube radius and the geometry of the channel on the bundle swelling is systematically analyzed. The most critical input is proved to be the C-H2 potential. Using the same model than in planar graphite, which is expected to be also accurate in nanotubes, the dilation is observed to be smaller than in previous estimations or even inexistent. H2 is highly unidimensional near the equilibrium density, the radial degree of freedom appearing progressively at higher densities.Comment: Accepted for publication in PR

QED3 theory of underdoped high temperature superconductors

Low-energy theory of d-wave quasiparticles coupled to fluctuating vortex loops that describes the loss of phase coherence in a two dimensional d-wave superconductor at T=0 is derived. The theory has the form of 2+1 dimensional quantum electrodynamics (QED3), and is proposed as an effective description of the T=0 superconductor-insulator transition in underdoped cuprates. The coupling constant ("charge") in this theory is proportional to the dual order parameter of the XY model, which is assumed to be describing the quantum fluctuations of the phase of the superconducting order parameter. The principal result is that the destruction of phase coherence in d-wave superconductors typically, and immediately, leads to antiferromagnetism. The transition can be understood in terms of the spontaneous breaking of an approximate "chiral" SU(2) symmetry, which may be discerned at low enough energies in the standard d-wave superconductor. The mechanism of the symmetry breaking is analogous to the dynamical mass generation in the QED3, with the "mass" here being proportional to staggered magnetization. Other insulating phases that break chiral symmetry include the translationally invariant "d+ip" and "d+is" insulators, and various one dimensional charge-density and spin-density waves. The theory offers an explanation for the rounded d-wave-like dispersion seen in ARPES experiments on Ca2CuO2Cl2 (F. Ronning et. al., Science 282, 2067 (1998)).Comment: Revtex, 20 pages, 5 figures; this is a much extended follow-up to the Phys. Rev. Lett. vol.88, 047006 (2002) (cond-mat/0110188); improved presentation, many additional explanations, comments, and references added, sec. IV rewritten. Final version, to appear in Phys. Rev.

Hadronic Cross-sections in two photon Processes at a Future Linear Collider

In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear $e^+e^-$ collider. We extend, to higher energy, our previous estimates of the accuracy with which the \gamgam\ cross-section needs to be measured, in order to distinguish between different theoretical models of energy dependence of the total cross-sections. We show that the necessary precision to discriminate among these models is indeed possible at future linear colliders in the Photon Collider option. Further we note that even in the $e^+e^-$ option a measurement of the hadron production cross-section via \gamgam processes, with an accuracy necessary to allow discrimination between different theoretical models, should be possible. We also comment briefly on the implications of these predictions for hadronic backgrounds at the future TeV energy $e^+e^-$ collider CLIC.Comment: 20 pages, 5 figures, LaTeX. Added an acknowledgemen

Doubly charged Higgs from ee-γ\gamma scattering in the 3-3-1 Model

We studied the production and signatures of doubly charged Higgs bosons in the process $\gamma e^- \rightarrow H^{--}E^+$, where $E^+$ is a heavy lepton, at the $e^-e^+$ International Linear Collider (ILC) and CERN Linear Collider (CLIC). The intermediate photons are given by the Weizs$\ddot{a}$cker-Williams and laser backscattering distributions. We found that significant signatures are obtained by bremsstrahlung and backward Comptom scattering of laser. A clear signal can be obtained for doubly charged Higgs bosons, doubly charged gauge bosons and heavy leptons

Associated Production of Heavy Quarkonia and Electroweak Bosons at Present and Future Colliders

We investigate the associated production of heavy quarkonia, with angular-momentum quantum numbers ^{2S+1}L_J = ^1S_0, ^3S_1, ^1P_1, ^3P_J (J = 0, 1, 2), and photons, Z bosons, and W bosons in photon-photon, photon-hadron, and hadron-hadron collisions within the factorization formalism of nonrelativistic quantum chromodynamics providing all contributing partonic cross sections in analytic form. In the case of photoproduction, we also include the resolved-photon contributions. We present numerical results for the processes involving J/psi and chi_{cJ} mesons appropriate for the Fermilab Tevatron, CERN LHC, DESY TESLA, operated in the e^+ e^- and gamma gamma modes, and DESY THERA.Comment: 41 pages (Latex), 10 figures (Postscript

Redesign and commissioning of sexual health services in England – a qualitative study

Objectives Responsibility for the commissioning of sexual and reproductive health (SRH) services transferred from the National Health Service to local authorities in England in 2013. This transfer prompted many local authorities to undertake new procurements of these SRH services. This study was undertaken to capture some of the lessons learnt in order to inform future commissioning and system redesign. Study design A qualitative study was carried out involving semi-structured interviews. Methods Interviews were conducted with 13 local authority sexual health commissioners in Yorkshire and the Humber from 11 interviews. Thematic analysis was used to identify themes from transcripts of the interviews with the 13 participants. Results Key themes identified were as follows: the challenge and complexity to those new to clinical commissioning; the prerequisites of robust infrastructural inputs to undertake the process, including technical expertise, a dependable project team, with clarity over the timescales and the budget; the requirement for good governance, stakeholder engagement and successful management of relationships with the latter; and the need to focus on the outcomes, aiming for value for money and improved system performance. Conclusions Several key issues emerged from our study that significantly influenced the outcome of the redesign and commissioning process for sexual health services. An adapted model of the Donabedian evaluation framework was developed to provide a tool to inform future system redesign. Our model helps identify the key determinants for successful redesign in this context which is essential to both mitigate potential risks and maximize the likelihood of successful outcomes. Our model may have wider applications

Discovery and Identification of W' Bosons in e gamma to nu q +X

We examine the sensitivity of the process e gamma to nu q +X to W' bosons which arise in various extensions of the standard model. We consider photon spectra from both the Weizsacker Williams process and from a backscattered laser. The process is found to be sensitive to W' masses up to several TeV, depending on the model, the center of mass energy, the integrated luminosity, and assumptions regarding systematic errors. If extra gauge bosons were discovered first in other experiments, the process could also be used to measure W' couplings. This measurement would provide information that could be used to unravel the underlying theory, complementary to measurements at the Large Hadron Collider.Comment: 17 pages, 9 figures, uses Revtex and epsfi

B_c meson production in \gamma\gamma collisions and charm content of the photon

Based on photon structure function formalism we have calculated $B_c(B_c^{*})$ meson production cross section in $\gamma\gamma$ collisions via partonic subprocess $c\gamma\to B_c(B_c^{*}) b$. It was shown that this approach gives the same results for $B_c^*(B_c)$ meson cross sections as the direct leading order QCD calculation of the subprocess $\gamma\gamma\to B_c(B_c^{*})b\bar c$ at small energy. Howere, opposite to the direct QCD calculation we have obtained the increase of the $B_c(B_c^{*})$ meson cross section at large energies. We have found also additional contribution to the $B_c$ meson production via the nonperturbative fluctuations $\gamma\leftrightarrow J/\psi$.Comment: LaTeX, 7 pages and 6 figures available upon reques