69 research outputs found
Adolescents' Responses to Having a Mother with Cancer
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
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 and a
mass resolution of 10 GeV one could expect to see a Higgs signal in
the channel with a 3-4 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
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
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
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 -system
are investigated for a wide range of relative -momenta and the
dynamical impact of color confinement on the quark motion is shown.Comment: 12 pages plus 5 figure
Production in Peripheral Heavy-Ion Collisions
We estimate the impact parameter dependence of the production cross section
for and mesons in peripheral heavy-ion collisions collisions.
Total and elastic 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
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
There exist several proposals to use Weizs\"{a}cker-Williams photons
generated by ultrarelativistic heavy ions to produce exotic particles in
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
fusion they include also electromagnetic interactions
and strong nucleon-nucleon interactions in grazing collisions. All these
processes are characterised by low multiplicities of produced particles.
and 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
events. The possibility of selecting mesons produced in
fusion events via different 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
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
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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