11,819 research outputs found
Invariant NKT cells and rheumatic disease: Focus on primary sjogren syndrome
Primary Sjogren syndrome (pSS) is a complex autoimmune disease mainly affecting salivary and lacrimal glands. Several factors contribute to pSS pathogenesis; in particular, innate immunity seems to play a key role in disease etiology. Invariant natural killer (NK) T cells (iNKT) are a T-cell subset able to recognize glycolipid antigens. Their function remains unclear, but studies have pointed out their ability to modulate the immune system through the promotion of specific cytokine milieu. In this review, we discussed the possible role of iNKT in pSS development, as well as their implications as future markers of disease activity
Lessons and Prospects from the pMSSM after LHC Run I: Neutralino LSP
We study SUSY signatures at the 7, 8 and 14 TeV LHC employing the
19-parameter, R-Parity conserving p(henomenological)MSSM, in the scenario with
a neutralino LSP. Our results were obtained via a fast Monte Carlo simulation
of the ATLAS SUSY analysis suite. The flexibility of this framework allows us
to study a wide variety of SUSY phenomena simultaneously and to probe for weak
spots in existing SUSY search analyses. We determine the ranges of the
sparticle masses that are either disfavored or allowed after the searches with
the 7 and 8 TeV data sets are combined. We find that natural SUSY models with
light squarks and gluinos remain viable. We extrapolate to 14 TeV with both 300
fb and 3 ab of integrated luminosity and determine the expected
sensitivity of the jets + MET and stop searches to the pMSSM parameter space.
We find that the high-luminosity LHC will be powerful in probing SUSY with
neutralino LSPs and can provide a more definitive statement on the existence of
natural Supersymmetry.Comment: 41 pages, 27 figures. arXiv admin note: substantial text overlap with
arXiv:1307.844
Observation of the Inverse Cotton-Mouton Effect
We report the observation of the Inverse Cotton-Mouton Effect (ICME) i.e. a
magnetization induced in a medium by non resonant linearly polarized light
propagating in the presence of a transverse magnetic field. We present a
detailed study of the ICME in a TGG crystal showing the dependence of the
measured effect on the light intensity, the optical polarization, and on the
external magnetic field. We derive a relation between the Cotton-Mouton and
Inverse Cotton-Mouton effects that is roughly in agreement with existing
experimental data. Our results open the way to applications of the ICME in
optical devices
Quenched Computation of the Complexity of the Sherrington-Kirkpatrick Model
The quenched computation of the complexity in the
Sherrington-Kirkpatrick model is presented. A modified Full Replica
Symmetry Breaking Ansatz is introduced in order to study the complexity
dependence on the free energy. Such an Ansatz corresponds to require
Becchi-Rouet-Stora-Tyutin supersymmetry. The complexity computed this way is
the Legendre transform of the free energy averaged over the quenched disorder.
The stability analysis shows that this complexity is inconsistent at any free
energy level but the equilibirum one. The further problem of building a
physically well defined solution not invariant under supersymmetry and
predicting an extensive number of metastable states is also discussed.Comment: 19 pages, 13 figures. Some formulas added corrected, changes in
discussion and conclusion, one figure adde
Complexity in Mean-Field Spin-Glass Models: Ising -spin
The Complexity of the Thouless-Anderson-Palmer (TAP) solutions of the Ising
-spin is investigated in the temperature regime where the equilibrium phase
is one step Replica Symmetry
Breaking. Two solutions of the resulting saddle point equations are found.
One is supersymmetric (SUSY) and includes the equilibrium value of the free
energy while the other is non-SUSY. The two solutions cross exactly at a value
of the free energy where the replicon eigenvalue is zero; at low free energy
the complexity is described by the SUSY solution while at high free energy it
is described by the non-SUSY solution. In particular the non-SUSY solution
describes the total number of solutions, like in the
Sherrington-Kirkpatrick (SK) model. The relevant TAP solutions corresponding
to the non-SUSY solution share the same feature of the corresponding solutions
in the SK model, in particular their Hessian has a vanishing isolated
eigenvalue. The TAP solutions corresponding to the SUSY solution, instead, are
well separated minima.Comment: 13 pages, 9 figure
Inverse Cotton-Mouton effect of the Vacuum and of atomic systems
In this letter we calculate the Inverse Cotton-Mouton Effect (ICME) for the
vacuum following the predictions of Quantum ElectroDynamics. We compare the
value of this effect for the vacuum with the one expected for atomic systems.
We finally show that ICME could be measured for the first time for noble gases
using state-of-the-art laser systems and for the quantum vacuum with
near-future laser facilities like ELI and HiPER, providing in particular a test
of the nonlinear behaviour of quantum vacuum at intensities below the Schwinger
limit of 4.5x10^33 W/m^2.Comment: Submitted to EP
Zeroing in on Supersymmetric Radiation Amplitude Zeros
Radiation amplitude zeros have long been used to test the Standard Model.
Here, we consider the supersymmetric radiation amplitude zero in
chargino-neutralino associated production, which can be observed at the
luminosity upgraded LHC. Such an amplitude zero only occurs if the neutralino
has a large wino fraction and hence this observable can be used to determine
the neutralino eigenstate content. We find that this observable can be measured
by comparing the p_T spectrum of the softest lepton in the trilepton
decay channel to that of a control process such as
or . We test this technique on a
previously generated model sample of the 19 dimensional parameter space of the
phenomenological MSSM, and find that it is effective in determining the wino
content of the neutralino.Comment: 19 pages, 7 figure
High contrast Mach-Zehnder lithium atom interferometer in the Bragg regime
We have constructed an atom interferometer of the Mach-Zehnder type,
operating with a supersonic beam of lithium. Atom diffraction uses Bragg
diffraction on laser standing waves. With first order diffraction, our
apparatus has given a large signal and a very good fringe contrast (74%), which
we believe to be the highest ever observed with atom interferometers. This
apparatus will be applied to high sensitivity measurementsComment: 6 pages, 3 figures, accepted by Appl. Phys.
Constraining the Symmetry Energy: A Journey in the Isospin Physics from Coulomb Barrier to Deconfinement
Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium
nuclear interaction in regions away from saturation. In this work we present a
selection of reaction observables in dissipative collisions particularly
sensitive to the isovector part of the interaction, i.e. to the symmetry term
of the nuclear Equation of State (EoS). At low energies the behavior of the
symmetry energy around saturation influences dissipation and fragment
production mechanisms. We will first discuss the recently observed Dynamical
Dipole Radiation, due to a collective neutron-proton oscillation during the
charge equilibration in fusion and deep-inelastic collisions. Important Iso-EOS
effects are stressed. Reactions induced by unstable 132Sn beams appear to be
very promising tools to test the sub-saturation Isovector EoS. New Isospin
sensitive observables are also presented for deep-inelastic, fragmentation
collisions and Isospin equilibration measurements (Imbalance Ratios). The high
density symmetry term can be derived from isospin effects on heavy ion
reactions at relativistic energies (few AGeV range), that can even allow a
``direct'' study of the covariant structure of the isovector interaction in the
hadron medium. Rather sensitive observables are proposed from collective flows
and from pion/kaon production. The possibility of the transition to a mixed
hadron-quark phase, at high baryon and isospin density, is finally suggested.
Some signatures could come from an expected ``neutron trapping'' effect. The
importance of studying violent collisions with radioactive beams from low to
relativistic energies is finally stressed.Comment: 15 pages, 5 figures, Int.Workshop on Nuclear Dynamics in Heavy Ion
Reactions and Neutron Stars, Beijing Normal Univ. July 07, to appear in
Int.Journ.Modern Physics E (2008
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