342 research outputs found
p p -> j j e+/- mu+/- nu nu and j j e+/- mu-/+ nu nu at O(\alpha_{em}^6) and O(\alpha_{em}^4 \alpha_s^2) for the Study of the Quartic Electroweak Gauge Boson Vertex at LHC
We analyze the potential of the CERN Large Hadron Collider (LHC) to study the
structure of quartic vector-boson interactions through the pair production of
electroweak gauge bosons via weak boson fusion q q -> q q W W. In order to
study these couplings we have performed a partonic level calculation of all
processes p p -> j j e+/- mu+/- nu nu and pp -> j j e+/- mu-/+ nu nu at the LHC
using the exact matrix elements at O(\alpha_{em}^6) and O(\alpha_{em}^4
\alpha_s^2) as well as a full simulation of the t tbar plus 0 to 2 jets
backgrounds. A complete calculation of the scattering amplitudes is necessary
not only for a correct description of the process but also to preserve all
correlations between the final state particles which can be used to enhance the
signal. Our analyses indicate that the LHC can improve by more than one order
of magnitude the bounds arising at present from indirect measurements.Comment: 26 pages, 8 figures, revised version with some typos corrected, and
some comments and references adde
Run Scenarios for the Linear Collider
Scenarios are developed for runs at a Linear Collider, in the case that there
is a rich program of new physics.Comment: 12 pages, 10 tables, Latex; Snowmass 2001 plenary repor
Testing Color Evaporation in Photon-Photon Production of J/Psi at CERN LEP II
The DELPHI Collaboration has recently reported the measurement of J/Psi
production in photon-photon collisions at LEP II. These newly available data
provide an additional proof of the importance of colored c bar{c} pairs for the
production of charmonium because these data can only be explained by
considering resolved photon processes. We show here that the inclusion of color
octet contributions to the J/Psi production in the framework of the color
evaporation model is able to reproduce this data. In particular, the
transverse-momentum distribution of the J/Psi mesons is well described by this
model.Comment: 10 pages, 5 Figures, Revtex
Expansion of anti-AFP Th1 and Tc1 responses in hepatocellular carcinoma occur in different stages of disease
Copyright @ 2010 Cancer Research UK. This work is licensed under the Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License.
To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/.Background: α-Fetoprotein (AFP) is a tumour-associated antigen in hepatocellular carcinoma (HCC) and is a target for immunotherapy. However, there is little information on the pattern of CD4 (Th1) and CD8 (Tc1) T-cell response to AFP in patients with HCC and their association with the clinical characteristics of patients.
Methods: We therefore analysed CD4 and CD8 T-cell responses to a panel of AFP-derived peptides in a total of 31 HCC patients and 14 controls, using an intracellular cytokine assay for IFN-γ.
Results: Anti-AFP Tc1 responses were detected in 28.5% of controls, as well as in 25% of HCC patients with Okuda I (early tumour stage) and in 31.6% of HCC patients with stage II or III (late tumour stages). An anti-AFP Th1 response was detected only in HCC patients (58.3% with Okuda stage I tumours and 15.8% with Okuda stage II or III tumours). Anti-AFP Th1 response was mainly detected in HCC patients who had normal or mildly elevated serum AFP concentrations (P=0.00188), whereas there was no significant difference between serum AFP concentrations in these patients and the presence of an anti-AFP Tc1 response. A Th1 response was detected in 44% of HCC patients with a Child–Pugh A score (early stage of cirrhosis), whereas this was detected in only 15% with a B or C score (late-stage cirrhosis). In contrast, a Tc1 response was detected in 17% of HCC patients with a Child–Pugh A score and in 46% with a B or C score.
Conclusion: These results suggest that anti-AFP Th1 responses are more likely to be present in patients who are in an early stage of disease (for both tumour stage and liver cirrhosis), whereas anti-AFP Tc1 responses are more likely to be present in patients with late-stage liver cirrhosis. Therefore, these data provide valuable information for the design of vaccination strategies against HCC.Association for International Cancer Research and Polkemmet Fund, London
Clinic
S, T, and Leptoquarks at HERA
If the recently discovered anomalous events at HERA are due to a scalar
leptoquark, then it is very likely to have weak isospin . In that
case, present precision measurements of the oblique radiative parameters
and provide strong constraints on the mass of the other component of this
doublet. If the standard model is extended to include such a doublet, a
slightly better fit may in fact be obtained. However, in specific proposed
models where this doublet comes from a larger symmetry, there are often
additional large and positive contributions to from exotic heavy fermions
which far exceed the present experimental limit. A way to improve the Tevatron
exploration of leptoquarks is proposed.Comment: 10 pages including 3 figure
Minimal Flavour Violation for Leptoquarks
Scalar leptoquarks, with baryon and lepton number conserving interactions,
could have TeV scale masses, and be produced at colliders or contribute to a
wide variety of rare decays. In pursuit of some insight as to the most
sensitive search channels, We assume that the leptoquark-lepton-quark coupling
can be constructed from the known mass matrices. We estimate the rates for
selected rare processes in three cases: leptoquarks carrying lepton and quark
flavour, leptoquarks with quark flavour only, and unflavoured leptoquarks. We
find that leptoquark decay to top quarks is an interesting search channel.Comment: 17 pages, 2 figures, minor changes and references adde
Histological Course of Nonalcoholic Fatty Liver Disease in Japanese Patients: Tight glycemic control, rather than weight reduction, ameliorates liver fibrosis
金沢大学医薬保健研究域医学系OBJECTIVE - The goal of this study was to examine whether metabolic abnormalities are responsible for the histological changes observed in Japanese patients with nonalcoholic fatty liver disease (NAFLD) who have undergone serial liver biopsies. RESEARCH DESIGN AND METHODS - In total, 39 patients had undergone consecutive liver biopsies. Changes in their clinical data were analyzed, and biopsy specimens were scored histologically for stage. RESULTS - The median follow-up time was 2.4 years (range 1.0-8.5). Liver fibrosis had improved in 12 patients (30.7%), progressed in 11 patients (28.2%), and remained unchanged in 16 patients (41%). In a Cox proportional hazard model, decrease in A1C and use of insulin were associated with improvement of liver fibrosis independent of age, sex, and BMI. However, ΔA1C was more strongly associated with the improvement of liver fibrosis than use of insulin after adjustment for each other (χ2; 7.97 vs. 4.58, respectively). CONCLUSIONS - Tight glycemic control may prevent histological progression in Japanese patients with NAFLD. © 2010 by the American Diabetes Association
Deep inelastic production at HERA in the -factorization approach and its consequences for the nonrelativistic QCD
In the framework of the -factorization approach, we analyse the
inclusive and inelastic production of particles in deep inelastic
scattering. We take into account both colour-singlet and colour-octet
production channels. We inspect the sensitivity of theoretical predictions to
the choice of model parameters. Our theoretical results agree reasonably well
with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure
New interactions in neutrino oscillations with three light flavors
If one assumes solar and LSND neutrino oscillations to explain the
corresponding data, then the atmospheric neutrino deficit cannot be
accommodated within the Standard Model with three light flavors, unless one
ignores the data's zenith-angle dependence. We propose a novel solution to this
problem by postulating large anomalous diagonal -quark interactions
which affect oscillations traversing the Earth and induce
the observed zenith-angle dependence.Comment: Final version, to appear in Phys. Rev. Letters dated May 25, 199
Analysis of Long-Lived Slepton NLSP in GMSB model at Linear Collider
We performed an analysis on the detection of a long-lived slepton at a linear
collider with GeV. In GMSB models a long-lived NLSP is predicted
for large value of the supersymmetry breaking scale . Furthermore in
a large portion of the parameter space this particle is a stau. Such heavy
charged particles will leave a track in the tracking volume and hit the muonic
detector. In order to disentangle this signal from the muon background, we
explore kinematics and particle identification tools: time of flight device,
dE/dX and Cerenkov devices. We show that a linear collider will be able to
detect long-lived staus with masses up to the kinematical limit of the machine.
We also present our estimation of the sensitivity to the stau lifetime.Comment: Minor changes, Ref. 10 fixed. 12 pages, RevTex, 4 eps figure
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