7,127 research outputs found
Photon Splitting in a Strong Magnetic Field: Recalculation and Comparison With Previous Calculations
We recalculate the amplitude for photon splitting in a strong magnetic field
below the pair production threshold, using the worldline path integral variant
of the Bern--Kosower formalism. Numerical comparison (using programs that we
have made available for public access on the Internet) shows that the results
of the recalculation are identical to the earlier calculations of Adler and
later of Stoneham, and to the recent recalculation by Baier, Milstein, and
Shaisultanov.Comment: Revtex, 9 pages, no figure
P02.69. Self administered acupuncture for treatment of chemotherapy associated nausea: a pilot study
Symmetry Breaking for Matter Coupled to Linearized Supergravity From the Perspective of the Current Supermultiplet
We consider a generic supersymmetric matter theory coupled to linearized
supergravity, and analyze scenarios for spontaneous symmetry breaking in terms
of vacuum expectation values of components of the current supermultiplet. When
the vacuum expectation of the energy momentum tensor is zero, but the scalar
current or pseudoscalar current gets an expectation, evaluation of the
gravitino self energy using the supersymmetry current algebra shows that there
is an induced gravitino mass term. The structure of this term generalizes the
supergravity action with cosmological constant to theories with CP violation.
When the vacuum expectation of the energy momentum tensor is nonzero,
supersymmetry is broken; requiring cancellation of the cosmological constant
gives the corresponding generalized gravitino mass formula.Comment: 11 page
Quantum-Liouville and Langevin Equations for Gravitational Radiation Damping
From a forward--backward path integral, we derive a master equation for the
emission and absorption of gravitons by a massive quantum object in a heat bath
of gravitons. Such an equation could describe collapse phenomena of dense
stars. We also present a useful approximate Langevin equation for such a
system.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of
paper (including all PS fonts) at
http://www.physik.fu-berlin.de/~kleinert/31
Comments on Proposed Gravitational Modifications of Schrodinger Dynamics and their Experimental Implications
We discuss aspects of gravitational modifications of Schrodinger dynamics
proposed by Diosi and Penrose. We consider first the Diosi-Penrose criterion
for gravitationally induced state vector reduction, and compute the reduction
time expected for a superposition of a uniform density cubical solid in two
positions displaced by a small fraction of the cube side. We show that the
predicted effect is much smaller than would be observable in the proposed
Marshall et al. mirror experiment. We then consider the ``Schrodinger -Newton''
equation for an N-particle system. We show that in the independent particle
approximation, it differs from the usual Hartree approximation applied to the
Newtonian potential by self-interaction terms, which do not have a consistent
Born rule interpretation. This raises doubts about the use of the
Schrodinger-Newton equation to calculate gravitational effects on molecular
interference experiments. When the effects of Newtonian gravitation on
molecular diffraction are calculated using the standard many-body Schrodinger
equation, no washing out of the interference pattern is predicted.Comment: Tex, 17
Photon Splitting in a Very Strong Magnetic Field
Photon splitting in a very strong magnetic field is analyzed for energy
. The amplitude obtained on the base of operator-diagram technique
is used. It is shown that in a magnetic field much higher than critical one the
splitting amplitude is independent on the field. Our calculation is in a good
agreement with previous results of Adler and in a strong contradiction with
recent paper of Mentzel et al.Comment: 5 pages,Revtex , 4 figure
Resonance decay effects on anisotropy parameters
We present the elliptic flow of pions produced from resonance decays.
The transverse momentum spectra of the parent particles are taken from
thermal model fits and their are fit under the assumption that they
follow number-of-constituent-quark (NCQ) scaling expected from
quark-coalescence models. The of pions from resonance particle decays is
found to be similar to the measured pion . We also propose the measurement
of electron as a means to extract open-charm and investigate
whether a thermalized system of quarks and gluons (a quark-gluon plasma) is
created in collisions of Au nuclei at RHIC.Comment: 5 pages, 4 figure
Broad-band polarization-independent total absorption of electromagnetic waves by an overdense plasma
We have shown both experimentally and theoretically that
polarization-independent broad-band absorption of electromagnetic waves by an
overdense plasma, caused by surface plasmon-polaritons (SPP) excitation, can be
achieved due to combination of two factors: a non-zero angle of incidence and a
two-dimensional circular diffraction grating placed at a properly chosen
distance in front of the plasma boundary. Direct detection of SPP has been
achieved for the first time using a miniature antenna imbedded in the plasma.Comment: considerably broadened versio
Atherogenic dyslipidemia in metabolic syndrome and type 2 diabetes: therapeutic options beyond statins
Lowering of low-density lipoprotein cholesterol with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) is clearly efficacious in the treatment and prevention of coronary artery disease. However, despite increasing use of statins, a significant number of coronary events still occur and many of such events take place in patients presenting with type 2 diabetes and metabolic syndrome. More and more attention is being paid now to combined atherogenic dyslipidemia which typically presents in patients with type 2 diabetes and metabolic syndrome. This mixed dyslipidemia (or "lipid quartet"): hypertriglyceridemia, low high-density lipoprotein cholesterol levels, a preponderance of small, dense low-density lipoprotein particles and an accumulation of cholesterol-rich remnant particles (e.g. high levels of apolipoprotein B) – emerged as the greatest "competitor" of low-density lipoprotein-cholesterol among lipid risk factors for cardiovascular disease. Most recent extensions of the fibrates trials (BIP – Bezafibrate Infarction Prevention study, HHS – Helsinki Heart Study, VAHIT – Veterans Affairs High-density lipoprotein cholesterol Intervention Trial and FIELD – Fenofibrate Intervention and Event Lowering in Diabetes) give further support to the hypothesis that patients with insulin-resistant syndromes such as diabetes and/or metabolic syndrome might be the ones to derive the most benefit from therapy with fibrates. However, different fibrates may have a somewhat different spectrum of effects. Other lipid-modifying strategies included using of niacin, ezetimibe, bile acid sequestrants and cholesteryl ester transfer protein inhibition. In addition, bezafibrate as pan-peroxisome proliferator activated receptor activator has clearly demonstrated beneficial pleiotropic effects related to glucose metabolism and insulin sensitivity. Because fibrates, niacin, ezetimibe and statins each regulate serum lipids by different mechanisms, combination therapy – selected on the basis of their safety and effectiveness – may offer particularly desirable benefits in patients with combined hyperlipidemia as compared with statins monotherapy
- …