529 research outputs found
SUSY GUT Model Building
I discuss an evolution of SUSY GUT model building, starting with the
construction of 4d GUTs, to orbifold GUTs and finally to orbifold GUTs within
the heterotic string. This evolution is an attempt to obtain realistic string
models, perhaps relevant for the LHC. This review is in memory of the sudden
loss of Julius Wess, a leader in the field, who will be sorely missed.Comment: 24 pages, 14 figures, lectures given at PiTP 2008, Institute for
Advanced Study, Princeton, to be published in the European Physical Journal
Fully supersymmetric CP violations in the kaon system
We show that, on the contrary to the usual claims, fully supersymmetric CP
violations in the kaon system are possible through the gluino mediated flavor
changing interactions. Both and can be accommodated for relatively large without any
fine tunings or contradictions to the FCNC and EDM constraints.Comment: Contribution to the Proceedings of ICHEP2000, Osaka, 200
Transverse Fresnel-Fizeau drag effects in strongly dispersive media
A light beam normally incident upon an uniformly moving dielectric medium is
in general subject to bendings due to a transverse Fresnel-Fizeau light drag
effect. In conventional dielectrics, the magnitude of this bending effect is
very small and hard to detect. Yet, it can be dramatically enhanced in strongly
dispersive media where slow group velocities in the m/s range have been
recently observed taking advantage of the electromagnetically induced
transparency (EIT) effect. In addition to the usual downstream drag that takes
place for positive group velocities, we predict a significant anomalous
upstream drag to occur for small and negative group velocities. Furthermore,
for sufficiently fast speeds of the medium, higher order dispersion terms are
found to play an important role and to be responsible for peculiar effects such
as light propagation along curved paths and the restoration of the spatial
coherence of an incident noisy beam. The physics underlying this new class of
slow-light effects is thoroughly discussed
B --> Phi K_S and Supersymmetry
The rare decay B --> Phi K_S is a well-known probe of physics beyond the
Standard Model because it arises only through loop effects yet has the same
time-dependent CP asymmetry as B --> Psi K_S. Motivated by recent data
suggesting new physics in B --> Phi K_S, we look to supersymmetry for possible
explanations, including contributions mediated by gluino loops and by Higgs
bosons. Chirality-preserving LL and RR gluino contributions are generically
small, unless gluinos and squarks masses are close to the current lower bounds.
Higgs contributions are also too small to explain a large asymmetry if we
impose the current upper limit on B(B_s --> mu mu). On the other hand,
chirality-flipping LR and RL gluino contributions can provide sizable effects
and while remaining consistent with related results in B --> Psi K_S, Delta
M_s, B --> X_s gamma and other processes. We discuss how the LR and RL
insertions can be distinguished using other observables, and we provide a
string-based model and other estimates to show that the needed sizes of mass
insertions are reasonable.Comment: 33 pages, 32 figures, Updated version for PRD. Includes discussions
of other recent works on this topic. Added discussions & plots for gluino
mass dependence and effects of theoretical uncertaintie
Analysis of the doubly heavy baryons in the nuclear matter with the QCD sum rules
In this article, we study the doubly heavy baryon states ,
, and in the nuclear matter using the QCD
sum rules, and derive three coupled QCD sum rules for the masses, vector
self-energies and pole residues. The predictions for the mass-shifts in the
nuclear matter , , and
can be confronted with the
experimental data in the future.Comment: 10 pages, 4 figure
Non-Invasive Mouse Models of Post-Traumatic Osteoarthritis
SummaryAnimal models of osteoarthritis (OA) are essential tools for investigating the development of the disease on a more rapid timeline than human OA. Mice are particularly useful due to the plethora of genetically modified or inbred mouse strains available. The majority of available mouse models of OA use a joint injury or other acute insult to initiate joint degeneration, representing post-traumatic osteoarthritis (PTOA). However, no consensus exists on which injury methods are most translatable to human OA. Currently, surgical injury methods are most commonly used for studies of OA in mice; however, these methods may have confounding effects due to the surgical/invasive injury procedure itself, rather than the targeted joint injury. Non-invasive injury methods avoid this complication by mechanically inducing a joint injury externally, without breaking the skin or disrupting the joint. In this regard, non-invasive injury models may be crucial for investigating early adaptive processes initiated at the time of injury, and may be more representative of human OA in which injury is induced mechanically. A small number of non-invasive mouse models of PTOA have been described within the last few years, including intra-articular fracture of tibial subchondral bone, cyclic tibial compression loading of articular cartilage, and anterior cruciate ligament (ACL) rupture via tibial compression overload. This review describes the methods used to induce joint injury in each of these non-invasive models, and presents the findings of studies utilizing these models. Altogether, these non-invasive mouse models represent a unique and important spectrum of animal models for studying different aspects of PTOA
Analysis of the baryons in the nuclear matter with the QCD sum rules
In this article, we study the and baryons in the
nuclear matter using the QCD sum rules, and obtain the in-medium masses
, , the
in-medium vector self-energies ,
, and the in-medium pole residues
,
. The mass-shifts are
and
, respectively.Comment: 7 pages, 8 figures, revised versio
Novel metallic states at low temperatures
We present an overview of unconventional metallic states arising close to magnetic quantum critical points with a focus on d-electron systems. The applicability and potential breakdowns of traditional self-consistent field theories of such materials are discussed as well as related phenomena in other systems
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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