6,841 research outputs found
Free Quarks and Antiquarks versus Hadronic Matter
Meson-meson reactions A(q_1 \bar{q}_1) + B(q_2 \bar{q}_2) to q_1 + \bar{q}_1
+ q_2 + \bar{q}_2 in high-temperature hadronic matter are found to produce an
appreciable amount of quarks and antiquarks freely moving in hadronic matter
and to establish a new mechanism for deconfinement of quarks and antiquarks in
hadronic matter.Comment: 9 pages, 3 figure
Top quark and Electroweak measurements at the Tevatron
We present recent preliminary measurements at the Tevatron of t-tbar and
single top production cross section, top quark mass and width, top pair spin
correlations and forward-backward asymmetry. In the electroweak sector, we
present the Tevatron average of the W boson width, and preliminary measurements
of the W and Z forward-backward asymmetries and WZ, ZZ diboson production cross
sections. All measurements are based on larger amount of collision data than
previously used and are in agreement with the standard model.Comment: 6 pages, 6 figures; In proceedings of the 16th International
Symposium on Particles, Strings and Cosmology, Valencia (Spain) 201
Gravitino Dark Matter in the CMSSM and Implications for Leptogenesis and the LHC
In the framework of the CMSSM we study the gravitino as the lightest
supersymmetric particle and the dominant component of cold dark matter in the
Universe. We include both a thermal contribution to its relic abundance from
scatterings in the plasma and a non--thermal one from neutralino or stau decays
after freeze--out. In general both contributions can be important, although in
different regions of the parameter space. We further include constraints from
BBN on electromagnetic and hadronic showers, from the CMB blackbody spectrum
and from collider and non--collider SUSY searches. The region where the
neutralino is the next--to--lightest superpartner is severely constrained by a
conservative bound from excessive electromagnetic showers and probably
basically excluded by the bound from hadronic showers, while the stau case
remains mostly allowed. In both regions the constraint from CMB is often
important or even dominant. In the stau case, for the assumed reasonable ranges
of soft SUSY breaking parameters, we find regions where the gravitino abundance
is in agreement with the range inferred from CMB studies, provided that, in
many cases, a reheating temperature \treh is large, \treh\sim10^{9}\gev. On
the other side, we find an upper bound \treh\lsim 5\times 10^{9}\gev. Less
conservative bounds from BBN or an improvement in measuring the CMB spectrum
would provide a dramatic squeeze on the whole scenario, in particular it would
strongly disfavor the largest values of \treh\sim 10^{9}\gev. The regions
favored by the gravitino dark matter scenario are very different from standard
regions corresponding to the neutralino dark matter, and will be partly probed
at the LHC.Comment: JHEP version, several improvements and update
Quark and Lepton Masses in 5D SO(10)
We construct a five dimensional supersymmetric SO(10)D grand
unified model with an orbifold as the extra
dimension. The orbifold breaks half of the supersymmetry and breaks the SO(10)
gauge symmetry down to . The Higgs mechanism is used to break the remaining gauge symmetry
the rest of the way to the Standard Model. We place matter fields variously in
the bulk and on the orbifold fixed points and the resulting massless fields are
mixtures between these brane and bulk fields. A chiral adjoint field in the
bulk gets a U(1) vacuum expectation value, resulting in an -dependent
localization of the bulk matter fields and the Standard Model Higgs field. This
Higgs field localization allows us to simultaneously explain the hierarchies
and . The model uses 11 parameters to fit the 13
independent low energy observables of the quark and charged lepton Yukawa
matrices. The model predicts the values of two quark mass combinations,
\f{m_u}{m_c} and , each of which are predicted to be
approximately above their experimental values. The remaining
observables are successfully fit at the 5% level.Comment: 52 pages, published version, includes more discussion of 6D version
of mode
Factorization of the charge correlation function in oscillations
Extraction of the mass difference from oscillations
involves tagging of bottom flavour at production and at decay. We show that the
asymmetry between the unmixed and mixed events factorizes into two parts, one
depending on the production-tag and the other on the decay-tag.Comment: 6 pages, Latex, no figure
Leptogenesis in models with multi-Higgs bosons
We study the leptogenesis scenario in models with multi-Higgs doublets. It is
pointed out that the washing-out process through the effective dimension five
interactions, which has not been taken into account seriously in the
conventional scenario, can be effective, and the resultant baryon asymmetry can
be exponentially suppressed. This fact implies new possible scenario where the
observed baryon asymmetry is the remnant of the washed out lepton asymmetry
which was originally much larger than the one in the conventional scenario. Our
new scenario is applicable to some neutrino mass matrix models which predict
too large CP-violating parameter and makes them viable through the washing-out
process.Comment: Latex 2e, 11 pages, 2 figures. Many parts in the original manuscript
have been revised, but conclusions are unchange
The T2K Indication of Relatively Large theta_13 and a Natural Perturbation to the Democratic Neutrino Mixing Pattern
The T2K Collaboration has recently reported a remarkable indication of the
\nu_\mu -> \nu_e oscillation which is consistent with a relatively large value
of \theta_{13} in the three-flavor neutrino mixing scheme. We show that it is
possible to account for such a result of \theta_{13} by introducing a natural
perturbation to the democratic neutrino mixing pattern, without or with CP
violation. A testable correlation between \theta_{13} and \theta_{23} is
predicted in this ansatz. We also discuss the Wolfenstein-like parametrization
of neutrino mixing, and comment on other possibilities of generating
sufficiently large \theta_{13} at the electroweak scale.Comment: RevTeX 8 page
Possible Excess in Charged Current Events with High-Q^2 at HERA from Stop and Sbottom Production
We investigate a production process e^+p \to \st X \to \sb W^+ X at HERA,
where we consider a decay mode \sb \to \bar{\nu}_e d of the sbottom in the
framework of an R-parity breaking supersymmetric standard model. Both processes
of the stop production e^+ d \to \st and the sbottom decay \sb \to
\bar{\nu}_e d are originated from an R-parity breaking superpotential
. One of signatures of the
process should be a large missing transverse momentum plus multijet events
corresponding to hadronic decays of the . It is shown that the signal could
appear as an event excess in the charged current (CC) processes with the high at HERA. We compare expected event distributions with
the CC data recently reported by the H1 and ZEUS groups at HERA. Methods for
extracting the signal from the standard CC processes are also discussed.Comment: 13 pages, LaTeX, 3 figure
Beyond the standard model physics at RHIC in polarized pp collision
A polarized hadron collider experiment must have a great discovery potential
for a search of physics beyond the standard model. Experimental data of various
symmetry tests at RHIC are going to be obtained within a few years. The author
developed a simulation tool, studying a sensitivity of hunting contact
interaction at RHIC by measuring parity violating spin asymmetries.Comment: 8 pages, 9 figure, Proc. of Praha-SPIN-200
The Serums Tool-Chain:Ensuring Security and Privacy of Medical Data in Smart Patient-Centric Healthcare Systems
Digital technology is permeating all aspects of human society and life. This leads to humans becoming highly dependent on digital devices, including upon digital: assistance, intelligence, and decisions. A major concern of this digital dependence is the lack of human oversight or intervention in many of the ways humans use this technology. This dependence and reliance on digital technology raises concerns in how humans trust such systems, and how to ensure digital technology behaves appropriately. This works considers recent developments and projects that combine digital technology and artificial intelligence with human society. The focus is on critical scenarios where failure of digital technology can lead to significant harm or even death. We explore how to build trust for users of digital technology in such scenarios and considering many different challenges for digital technology. The approaches applied and proposed here address user trust along many dimensions and aim to build collaborative and empowering use of digital technologies in critical aspects of human society
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