69 research outputs found

    Adolescents' Responses to Having a Mother with Cancer

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    Introduction: Each year potentially 1:270 children in the US are affected by the diagnosis of cancer in their mother. The diagnosis of cancer in a woman may cause changes in her behavior, emotions, and physical and family functioning (Lewis, 1996). In turn, these changes may impact her adolescent's behavior, school performance, emotions, and physical functioning (Visser et al., 2004). Purpose: The purpose of this study was to elicit and understand the adolescents' experience of having a mother with early stage cancer, the meaning that adolescents construct about having a mother with early stage cancer, and the processes that adolescents use in coping with having a mother with early stage cancer. Methods: This qualitative study used a grounded theory method to guide the exploration of the experience of male and female adolescents, ages 12-17 years, whose mother had been diagnosed with early stage cancer a minimum of 6 months and a maximum of 2 years ago. Each early stage cancer had a 5-year relative survival rate of 80% or greater. Adolescents' responses were elicited by a semi-structured interview guide. Findings: Adolescents experienced a process after their mother was diagnosed with cancer. After they learned the diagnosis, the process became cyclical and at times simultaneous, as cancer changed the family, the adolescents' coped, and demonstrated a sense of purpose. Conclusions: Having a mother with cancer is a significant life changing event for adolescents

    An intermediate-mass Higgs boson in two-photon coherent processes at the LHC

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    We reexamine the prospects of searching for a neutral Higgs boson in the intermediate-mass range, using the proton- and ion-beam facilities of the LHC to study coherent two-photon processes. Considering realistic design luminosities for the different ion beams, we find that beams of light-to-medium size ions like calcium will give the highest production rates. With a suitable trigger and assuming a b-quark identification efficiency of 30%30\% and a bbˉb{\bar b} mass resolution of 10 GeV one could expect to see a Higgs signal in the bbˉb{\bar b} channel with a 3-4 σ\sigma statistical significance in the first phase of operation of the LHC with beams of calcium.Comment: 10 pages of LATEX + 3 Figures (postscript

    Two- and Three-photon Fusion in Relativistic Heavy ion Collisions

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    The production of mesons in ultra-peripheral collisions of relativistic heavy ions is re-analyzed using a projection technique to calculate the amplitudes for the appropriate Feynman diagrams. The virtuality of the exchanged photons is fully accounted for in this approach. In the case of two-photon fusion, it is explicitly shown that the inclusion of nuclear form factors validates the equivalent photon approximation. However, this does not apply to three-photon fusion cross sections. The cross section of J/\psi production in ultra-peripheral collisions at RHIC and LHC are shown to be much smaller than the cross sections for the production of C=even mesons of similar masses.Comment: Version to be published in Nuclear Physics

    Suppression of Heavy Ion gamma gamma Production of the Higgs by Coulomb Dissociation

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    Predicted two-photon Higgs production with heavy ions at LHC is shown to be reduced due to the large Coulomb dissociation cross section. Incorporating the effect of dissociation reduces the production of a 100 GeV Higgs by about a factor of three compared to rates in the literature calculated without this effect.Comment: 5 pages, latex, revtex source, two postscript figure

    A Dynamical Model of Color Confinement

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    A dynamical model of confinement based on a transport theoretical description of the Friedberg-Lee model is extended to explicit color degrees of freedom. The string tension is reproduced by an adiabatic string formation from the nucleon ground state. Color isovector oscillation modes of a qqˉq\bar{q}-system are investigated for a wide range of relative qqˉq\bar{q}-momenta and the dynamical impact of color confinement on the quark motion is shown.Comment: 12 pages plus 5 figure

    η\eta Production in Peripheral Heavy-Ion Collisions

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    We estimate the impact parameter dependence of the production cross section for ηc\eta_c and ηb\eta_b mesons in peripheral heavy-ion collisions collisions. Total and elastic γγ\gamma\gamma cross sections are calculated in an equivalent photon approximation.Comment: 9 pages, uuencoded postscrip

    Searching for Anomalous Higgs Couplings in Peripheral Heavy Ion Collisions at the LHC

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    We investigate the sensitivity of the heavy ion mode of the LHC to anomalous Higgs boson couplings to photons, H-photon-photon, through the analysis of the processes photon photon to b anti-b and photon photon to photon photon in peripheral heavy ion collisions. We suggest cuts to improve the signal over background ratio and determine the capability of LHC to impose bounds on anomalous couplings by searching for a Higgs boson signal in these modes.Comment: 10 pages, RevTeX, 4 figures included using epsfig, revised versio

    Inclusive meson production in peripheral collisions of ultrarelativistic heavy ions

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    There exist several proposals to use Weizs\"{a}cker-Williams photons generated by ultrarelativistic heavy ions to produce exotic particles in γγ\gamma\gamma fusion reactions. To estimate the background conditions for such reactions we analyze various mechanisms of meson production in very peripheral collisions of ultrarelativistic heavy ions at RHIC and LHC energies. Besides γγ\gamma\gamma fusion they include also electromagnetic γA\gamma A interactions and strong nucleon-nucleon interactions in grazing AAAA collisions. All these processes are characterised by low multiplicities of produced particles. γA\gamma A and AAAA events are simulated by corresponding Monte Carlo codes, RELDIS and FRITIOF. In each of these processes a certain fraction of pions is produced close to the mid-rapidity region that gives a background for the γγ\gamma\gamma events. The possibility of selecting mesons produced in γγ\gamma\gamma fusion events via different ptp_t cut procedures is demonstrated.Comment: 27 pages with 4 eps-figures included, uses axodraw.sty Tab.2 and 3 correcte

    Photon-Photon and Pomeron-Pomeron Processes in Peripheral Heavy Ion Collisions

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    We estimate the cross sections for the production of resonances, pion pairs and a central cluster of hadrons in peripheral heavy-ion collisions through two-photon and double-pomeron exchange, at energies that will be available at RHIC and LHC. The effect of the impact parameter in the diffractive reactions is introduced, and imposing the condition for realistic peripheral collisions we verify that in the case of very heavy ions the pomeron-pomeron contribution is indeed smaller than the electromagnetic one. However, they give a non-negligible background in the collision of light ions. This diffractive background will be more important at RHIC than at LHC.Comment: 22 pages, 1 Postscript figures, 4 tables, to appear in Phys. Rev.

    Exclusive Production of Higgs Bosons in Hadron Colliders

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    We study the exclusive, double--diffractive production of the Standard Model Higgs particle in hadronic collisions at LHC and FNAL (upgraded) energies. Such a mechanism would provide an exceptionally clean signal for experimental detection in which the usual penalty for triggering on the rare decays of the Higgs could be avoided. In addition, because of the color singlet nature of the hard interaction, factorization is expected to be preserved, allowing the cross--section to be related to similar hard--diffractive events at HERA. Starting from a Fock state expansion in perturbative QCD, we obtain an estimate for the cross section in terms of the gluon structure functions squared of the colliding hadrons. Unfortunately, our estimates yield a production rate well below what is likely to be experimentally feasible.Comment: 17 pages, RevTeX file, four uufiled PostScript figures. UMPP #94-177. (Revised version. Some mistakenly missing Feynman diagrams are now added. Results do not change qualitatively. Paper reorganized.
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