Gluon Condensates, Chiral Symmetry Breaking and Pion Wave Function

We consider here chiral symmetry breaking in quantum chromodynamics arising from gluon condensates in vacuum. Through coherent states of gluons simulating a mean field type of approximation, we show that the off-shell gluon condensates of vacuum generate a mass-like contribution for the quarks, giving rise to chiral symmetry breaking. We next note that spontaneous breaking of global chiral symmetry links the four component quark field operator to the pion wave function. This in turn yields many hadronic properties in the light quark sector in agreement with experiments, leading to the conclusion that low energy hadron properties are primarily driven by the vacuum structure of quantum chromodynamics.Comment: 25 pages, IP/BBSR/92-76, revte

Bone health in adult women with ED: A longitudinal community-based study

Although Eating Disorders (ED) are known to affect bone health and development, little is known about the longitudinal effect of ED and ED behaviours on bone health in community dwelling adult women. Women (n = 3507) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) participated in a two-phase prevalence study to assess lifetime ED and ED behaviours (fasting, restrictive eating, vomiting and misuse of medication). Crude and adjusted linear regression methods investigated the association between ED diagnoses and behaviours, and total body, hip, leg and arm bone mineral density (BMD) DXA scans at mean ages of 48 and 52 years. Lifetime occurrence of Anorexia Nervosa (AN) was associated with lower BMD Z-scores for the whole body (mean difference (MD) = −0.28; 95% CI: -0.49, −0.05), hip (MD = −0.45; 95% CI -0.74, −0.16), leg (MD = −0.28; 95% CI -0.52, −0.03) and arm (MD = −0.44; 95% CI -0.68, −0.19) compared to no ED. This effect was mostly accounted for by lowest ever BMI. In post-hoc analyses, Restrictive AN, but not Binge-Purge AN was associated with a lower total body BMD Z-scores (MD = −0.37; 95% CI -0.62, −0.12). Lifetime Fasting and Restrictive Eating were associated with low BMD of the total body, hip, arm and leg in adjusted analyses, all p < 0.05. Both lifetime ED diagnoses and ED behaviours in a large community sample were predictive of low BMD in mid-life. This study confirms that the effects of AN, fasting and restrictive eating, and low BMI on bone health seen in clinical samples also occur in community samples

Quantum Mechanics as a Framework for Dealing with Uncertainty

Quantum uncertainty is described here in two guises: indeterminacy with its concomitant indeterminism of measurement outcomes, and fuzziness, or unsharpness. Both features were long seen as obstructions of experimental possibilities that were available in the realm of classical physics. The birth of quantum information science was due to the realization that such obstructions can be turned into powerful resources. Here we review how the utilization of quantum fuzziness makes room for a notion of approximate joint measurement of noncommuting observables. We also show how from a classical perspective quantum uncertainty is due to a limitation of measurability reflected in a fuzzy event structure -- all quantum events are fundamentally unsharp.Comment: Plenary Lecture, Central European Workshop on Quantum Optics, Turku 2009

Three Generations of SUSY Standard Model of Nambu-Goto String

A four dimensional Superstring is constructed starting from a twenty six dimensional bosonic string. Fermions are introduced by noting the Manselstam's proof of equivalence of two fermions to one boson in 1+1 dimensions. The action of the superstring is invariant under SO(6)$\times$ SO(5). It has four bosonic coordinates and twenty four Majorana fermions of SO(3,1) representing two transverse modes of super fermions and conformal ghosts (b,c). The super conformal ghosts ($\beta, \gamma$) are the quanta of an extended Hilbert space of the remaining longitudinal modes of two superfermions. The massless spectrum obtained by quantising the action, contain vector mesons which are generators of the SO(6)$\times$SO(5). Using Wilson loops, this product group is proven to descend to $Z_3\times SU(3)\times SU(2)\times U(1)$ without breaking supersymmetry.Thus there are just three generations of quarks and leptons.Comment: 11 page

Damped harmonic oscillator interpretation of the soft-state power spectra of Cyg X-1

We develop a model of an accretion disc in which the variability induced at a given radius is governed by a damped harmonic oscillator at the corresponding epicyclic frequency. That variability induces both linear and non-linear responses in the locally emitted radiation. The total observed variability of a source is the sum of these contributions over the disc radius weighted by the energy dissipation rate at each radius. It is shown that this simple model, which effectively has only three parameters including the normalization, can explain the range of the power spectra observed from Cyg X-1 in the soft state. Although a degeneracy between the black hole mass and the strength of the damping does not allow a unique determination of the mass, we can still constrain it to <16--20 solar masses. We also show that our model preserves the observed linear rms-flux relationship even in the presence of the non-linear flux response.Comment: MNRAS (Letters), in pres

A high-density relativistic reflection origin for the soft and hard X-ray excess emission from Mrk 1044

We present the first results from a detailed spectral-timing analysis of a long ($\sim$130 ks) XMM-Newton observation and quasi-simultaneous NuSTAR and Swift observations of the highly-accreting narrow-line Seyfert 1 galaxy Mrk 1044. The broadband (0.3$-$50 keV) spectrum reveals the presence of a strong soft X-ray excess emission below $\sim$1.5 keV, iron K$_{\alpha}$ emission complex at $\sim$6$-$7 keV and a `Compton hump' at $\sim$15$-$30 keV. We find that the relativistic reflection from a high-density accretion disc with a broken power-law emissivity profile can simultaneously explain the soft X-ray excess, highly ionized broad iron line and the Compton hump. At low frequencies ($[2-6]\times10^{-5}$ Hz), the power-law continuum dominated 1.5$-$5 keV band lags behind the reflection dominated 0.3$-$1 keV band, which is explained with a combination of propagation fluctuation and Comptonization processes, while at higher frequencies ($[1-2]\times10^{-4}$ Hz), we detect a soft lag which is interpreted as a signature of X-ray reverberation from the accretion disc. The fractional root-mean-squared (rms) variability of the source decreases with energy and is well described by two variable components: a less variable relativistic disc reflection and a more variable direct coronal emission. Our combined spectral-timing analyses suggest that the observed broadband X-ray variability of Mrk~1044 is mainly driven by variations in the location or geometry of the optically thin, hot corona.Comment: 23 pages, 19 figures, 4 tables, Published in MNRA

Timelapse

We discuss the existence in an arbitrary frame of a finite time for the transformation of an initial quantum state into another e.g. in a decay. This leads to the introduction of a timelapse $\tilde{\tau}$ in analogy with the lifetime of a particle. An argument based upon the Heisenberg uncertainty principle suggests the value of $\tilde{\tau}=1 / M_0$. Consequences for the exponential decay formula and the modifications that $\tilde{\tau}$ introduces into the Breit-Wigner mass formula are described.Comment: 5 pages [2 figs], ReV-Te