Searcharxiv⌕ Search

arXiv subjects

Y. N. Srivastava

Publications and source records attributed to Y. N. Srivastava.

At least 109 records · Page 6Linked to original sources
arXiv2003

The Clausius-Mossotti Phase Transition in Polar Liquids

The conventional Clausius-Mossotti polarization equation of state is known to be unstable for polar liquids having molecules with high polarizability. Room temperature water is an important example. The instability in the polarization equation of state is of the typical loop form requiring an ``equal area'' construction for studying the stable ordered phase. The ordered phase of a Clausius-Mossotti polar liquid then consists of domains each having a net polarization. The polarization may vary in direction from domain to domain. The ordered phases are quite similar to those previously discussed on the basis of Dicke superradiance.

cond-mat.stat-mech↗
arXiv2003

Quantum dissipation induced noncommutative geometry

The quantum statistical dynamics of a position coordinate x coupled to a reservoir requires theoretically two copies of the position coordinate within the reduced density matrix description. One coordinate moves forward in time while the other coordinate moves backward in time. It is shown that quantum dissipation induces, in the plane of the forward and backward motions, a noncommutative geometry. The noncommutative geometric plane is a consequence of a quantum dissipation induced phase interference which is closely analogous to the Aharanov-Bohm effect.

quant-ph↗
arXiv2002

Landau Ghosts and Anti-Ghosts in Condensed Matter and High Density Hadronic Matter

It is observed that the ``ghost'' (originally discovered by Landau in quantum electro-dynamics) and its counterparts in other theories are indeed ubiquitous as they occur in a one-loop approximation to any conventional (unbroken) gauge theory. The mechanism is first exposed in its generality via the Dyson equation and a simple but explicit example in condensed matter is provided through the static Clausius-Mossotti and its dynamic counterpart the Lorenz-Lorentz equation. The physical phase transition phenomenon associated with it is found to be super-radiance. We verify quantitatively that water (and many other polar liquids) are indeed super-radiant at room temperature. In quantum chromo-dynamics on the other hand, we encounter, thanks to asymptotic freedom, an ``anti-ghost'' which is closely associated with color confinement. Thus, in QCD, free quarks and glue exist in a super-radiant phase and hadronic matter in the normal one.

hep-ph↗
arXiv2002

Thermodynamic QED Coherence in Condensed Matter: Microscopic Basis of Thermal Superradiance

Electromagnetic superradiant field coherence exists in a condensed matter system if the electromagnetic field oscillators undergo a mean displacement. Transitions into thermal states with ordered superradiant phases have been shown to theoretically exist in Dicke-Preparata models. The theoretical validity of these models for condensed matter has been called into question due to non-relativistic diamagnetic terms in the electronic Hamiltonian. The microscopic bases of Dicke-Preparata thermal superradiance for realistic macroscopic systems are explored in this work. The impossibility of diaelectric correlations in condensed matter systems (via the Landau-Lifshitz theorem) provides a strong theoretical basis for understanding the physical reality of condensed matter thermodynamic superradiant phases.

cond-mat.stat-mech↗
arXiv2002

Thermal Superradiance and the Clausius-Mossotti Lorentz-Lorenz Equations

Electric polarization phenomena in insulating systems have long been described in mean field theory by the (static) Clausius-Mossotti or (dynamic) Lorentz-Lorenz polarizabilities. It is here shown, in the strong coupling regime, that a thermodynamic phase instability exists in these models. The resulting thermodynamic phase diagram coincides with that obtained from Dicke-Preparata model of thermal superradiance.

cond-mat.stat-mech↗
arXiv2002

Temperature of a Compressed Bubble with Application to Sonoluminescence

The rise in temperature from the adiabatic compression of a bubble is computed in thermodynamic mean field (van der Waals) theory. It is shown that the temperature rise is higher for the noble gas atoms than for more complex gas molecules. The adiabatic temperature rise is shown to be sufficient for producing sonoluminescence via the excited electronic states of the atoms.

cond-mat↗
arXiv2002

Radiation Induced Landau-Lifshitz-Gilbert Damping in Ferromagnets

The Landau-Lifshitz-Gilbert damping coefficient employed in the analysis of spin wave ferromagnetic resonance is related to the electrical conductivity of the sample. The changing magnetization (with time) radiates electromagnetic fields. The electromagnetic energy is then absorbed by the sample and the resulting heating effect describes magnetic dissipative damping. The ferromagnetic resonance relaxation rate theoretically depends on the geometry (shape and size) of the sample as well as temperature in agreement with experiment.

cond-mat.stat-mech↗
arXiv2001

Electric Field Effects and the Experimental Value of the Muon g-2 Anomaly

The electric field corrections to the recently measured muon magnetic moment g-2 anomaly are considered from both the classical (BMT) and the quantum mechanical (Dirac) viewpoints. In both views, we prove that the electric field inducing the horizontal betatron tune does not renormalize the anomaly frequency. With this result kept in mind, the experimental muon magnetic moment anomaly is in closer agreement with standard model predictions than has been previously reported.

hep-ph↗
arXiv2001

Coherent Betatron Oscillation and Induced Errors in the Experimental Determination of the Muon g-2 Factor

Precision measurements of the anomalous magnetic moment of the muon depend on the correct collective mode assignment of the coherent betatron oscillations in the beam. Presently, there is a disagreement between experiment and theory for the horizontal betatron frequency. The discrepancy is here resolved by our computations of electrostatic beam focusing. The correct treatment of the betatron effects renders less likely the need for non-standard model corrections to the muon g-2.

hep-ph↗
arXiv2001

Signal of heavy Majorana neutrinos at hadron colliders

The lepton number violating signal of like-sign-dileptons (LSD), p p \to \ell^\pm\ell^\pm + 2 jets, is investigated within a model of mixing in the neutrino sector assuming the existence of heavy Majorana neutrino states with a left--handed coupling to the light leptons. The LSD signal receives contributions both from the resonant production of a heavy Majorana neutrino (N) and from the exchange of a virtual N in the WW fusion mechanisms. These two possibilities are discussed in detail and compared. Helicity amplitudes are given pointing out differences with calculations previously reported by other authors. The signal cross--sections are computed at the energy of the LHC collider (sqrt{S}=14 TeV) at CERN and within the existing experimental limits on the mixing couplings, including those coming from neutrinoless double beta decay. Detailed angular distributions of signal reactions which are complementary to previous studies on the argument are presented.

hep-ph↗
arXiv2001

Klein Paradox for Optical Scattering from Excited Targets

The well known Klein paradox for the relativistic Dirac wave equation consists in the computation of possible ``negative probabilities'' induced by certain potentials in some regimes of energy. The paradox may be resolved employing the notion of electron-positron pair production in which the number of electrons present in a process can increase. The Klein paradox also exists in Maxwell's equations viewed as the wave equation for photons. In a medium containing ``inverted energy populations'' of excited atoms, e.g. in a LASER medium, one may again compute possible ``negative probabilities''. The resolution of the electromagnetic Klein paradox is that when the atoms decay, the final state may contain more photons then were contained the initial state. The optical theorem total cross section for scattering photons from excited state atoms may then be computed as negative within a frequency band with matter induced amplification.

quant-ph↗
arXiv2000

Hadronic Equipartition of Quark and Glue Momenta

If the ``glue'' which binds quarks within hadrons takes the form of strings, then a virial theorem may be derived which shows how the total hadron four momentum splits up into a quark contribution plus a glue contribution. The hadrons made up of light quarks exhibit an equipartion of four momentum into equal parts quarks and glue. The agreement with the experimental ``parton'' distribution four momentum sum rule is quite satisfactory as is the string fragmentation model.

hep-ph↗
arXiv2000

Super-Radiance and the Unstable Photon Oscillator

If the damping of a simple harmonic oscillator from a thermally random force is sufficiently strong, then the oscillator may become unstable. For a photon oscillator (radiatively damped by electric dipole moments), the instability leads to a low temperature Hepp-Lieb-Preparata super-radiant phase transition. The stable oscillator regime is described by the free energy of the conventional Casimir effect. The unstable (strongly damped) oscillator has a free energy corresponding to Dicke super-radiance.

cond-mat.stat-mech↗
arXiv2000

Gauge Invariant Formulations of Dicke-Preparata Super-Radiant Models

In a gauge invariant formulation of the molecular electric dipole-photon interaction, the rigorous coupling is strictly linear in the photon creation and photon annihilation operators. The linear coupling allows for a super-radiant phase transition as in the Hepp-Lieb formulation. A previous notion of a quadratic-coupling ``no-go theorem'' for super-radiance is incorrect. Also incorrect is a previous assertion that the dipole-photon coupling has absolutely no effect on the thermal equations of state. These dubious assertions were based on incorrect canonical transformations which eliminated the electric field (and thereby eliminated the dipole-photon interaction) which is neither mathematically nor physically consistent. The correct form of the canonical transformations are given in this work which allows for the physical reality of super-radiant condensed matter phases.

cond-mat.stat-mech↗
arXiv2000

Net Charge on a Noble Gas Atom Adsorbed on a Metallic Surface

Adsorbed noble gas atoms donate (on the average) a fraction of an electronic charge to the substrate metal. The effect has been experimentally observed as an adsorptive change in the electronic work function. The connection between the effective net atomic charge and the binding energy of the atom to the metal is theoretically explored.

cond-mat↗
arXiv2000

Higgs Decay into Gravitons: Trees and Loops

The decay of the Higgs particle into two gravitons was previously calculated by us using a Born term from the Einstein field equations. Subsequently, others computed the same decay via one loop diagrams but omitting the Born terms. Here all of the diagrams up to one loop are discussed, and it is shown that the Born term is overwhelmingly dominant in agreement with our original results.

hep-ph↗