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A fast and parametric digitization for triple-GEM detectorsApr 12 2019Triple-GEM detectors are a well known technology in high energy physics. In order to have a complete understanding of their behavior, in parallel with on beam testing, a Monte Carlo code has to be developed to simulate their response to the passage of ... More

Photon beam asymmetry $Σ$ for $η$ and $η^\prime$ photoproduction from the protonMar 01 2017Measurements of the linearly-polarized photon beam asymmetry $\Sigma$ for photoproduction from the proton of $\eta$ and $\eta^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic ... More

Double $K_S^0$ Photoproduction off the Proton at CLASDec 06 2017The $f_0$(1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the $f_0$(1500) ... More

Target and beam-target spin asymmetries in exclusive pion electroproduction for $Q^2>1$ GeV$^2$. II. $e p \rightarrow e π^0 p$Nov 15 2016Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^0$ electroproduction reaction $\gamma^* p \to p \pi^0$, expanding an analysis of the $\gamma^* p \to n \pi^+$ reaction from the same experiment. ... More

Measurement of the beam asymmetry $Σ$ and the target asymmetry $T$ in the photoproduction of $ω$ mesons off the proton using CLAS at Jefferson LaboratoryNov 14 2017May 10 2018The photoproduction of $\omega$ mesons off the proton has been studied in the reaction $\gamma p\to p\,\omega$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas Jefferson National Accelerator ... More

A model to explain angular distributions of $J/ψ$ and $ψ(2S)$ decays into $Λ\overlineΛ$ and $Σ^0\overlineΣ^0$Sep 12 2018Nov 30 2018BESIII data show a particular angular distribution for the decay of the $J/\psi$ and $\psi(2S)$ mesons into the hyperons $\Lambda\overline{\Lambda}$ and $\Sigma^0\overline{\Sigma}^0$. More in details the angular distribution of the decay $\psi(2S) \to ... More

Measurement of the Q^2 Dependence of the Deuteron Spin Structure Function g_1 and its Moments at Low Q^2 with CLASNov 06 2017Aug 14 2018We measured the $g_1$ spin structure function of the deuteron at low $Q^{2}$, where QCD can be approximated with chiral perturbation theory ($\chi$PT). The data cover the resonance region, up to an invariant mass of $W\approx1.9$~GeV. The generalized ... More

The HPS electromagnetic calorimeterOct 14 2016The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called "heavy photon". Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable ... More

Bridge between Hadrodynamics \& HEP: Regional CP Violation in Beauty \& Charm DecaysAug 23 2016There is a long way from `accuracy' to `precision' about {\bf CP} asymmetries in the decays of beauty \& charm hadrons. (a) We have to apply consistent parametrization of the CKM matrix. (b) Probing many-body final states (FS) is {\em not} a back-up for ... More

Memorial Contribution about Kolya Uraltsev's Talk at 2012 Workshop $B\to D**$Jul 02 2013Jul 14 2013Uraltev has given us a deeper understanding of the forces underlying the data from beauty and charm hadrons for the last 35 years and neutron EDM in the future -- in particular about non-perturbative QCD. At the Workshop in the November 2012 before his ... More

The Sybils' Advice on Charm (and $τ$ Leptons)Apr 05 2006The importance of future studies of charm and $\tau$ decays is emphasized as probes of New Physics: the most powerful tools are \cp asymmetries in charm and $\tau$ decays both in partial widths and final state distributions. While these searches for \cp ... More

The Battle of Albuera, the FC Liverpool and the Standard ModelMar 12 2006The Standard Model despite its well-known short comings is unlikely to yield without offering stubborn resistance. There are compelling arguments that New Physics lurks around the TeV scale. Continuing comprehensive studies of beauty, $\tau$ and charm ... More

Quo Vadis, Fascinum?Aug 14 1995The recent progress in our understanding of heavy-flavour decays allows us to define more reliably which future measurements on charm decays are needed to further advance our understanding of QCD and to get our theoretical tools ready for treating beauty ... More

Beauty Physics in the Next 15 Years -- an Itinerary for a Long Journey towards an Essential GoalJul 06 1994After re-stating why beauty physics is so special and sketching its present status I attempt to map out an itinerary for the next fifteen years. The basic elements are listed for a research program that allows to define and probe the KM unitarity triangle ... More

Weak Decays Of Charm Hadrons: The Next Lesson On QCD -- And Possibly More!Nov 01 1993Second-generation theoretical technologies -- heavy quark expansions, QCD sum rules and QCD simulations on the lattice -- are arriving on the scene, allowing a treatment of charm decays that is genuinely based on QCD. The availability of those theoretical ... More

On the Brink of Major Discoveries in Weak Charm Decays -- a Bismarckian Chance to Make HistoryOct 15 2007The recently obtained strong evidence for $D^0 - \bar D^0$ oscillations from the $B$ factories provides an important benchmark in our search for New Physics in charm transitions. While the theoretical verdict on the observed values of $x_D$ and $y_D$ ... More

The Physics of Beauty (& Charm [& $τ$]) at the LHC and in the Era of the LHCAug 20 2006The recent successes of the SM do not weaken the arguments in favour of New Physics residing at the TeV scale. Finding and identifying it represents the prime challenge for a generation of high energy physicists. To differentiate between different scenarios ... More

Measuring Absolute Branching Ratios of Charmed Baryons in $B$ DecaysNov 14 2001The $B$ factories are expected to provide huge samples of single $B$ decay events with little background by reconstructing one of the $B$ mesons produced in $\Upsilon (4S)$ decays. This represents a new experimental paradigm: such samples will allow to ... More

Heavy Flavour Physics: On Its More Than 50 Years Of History, Its Future And The Rio ManifestoDec 13 2000Dec 23 2000After a reminder about how $\Delta S\neq 0$ physics has been instrumental for the development of the Standard Model I sketch theoretical technologies for dealing with nonperturbative QCD in heavy flavour decays and state predictions for CP odd effects ... More

The Lifetimes of Heavy Flavour Hadrons - a Case Study in Quark-Hadron DualityJan 01 2000The status of heavy quark expansions for charm and beauty lifetime ratios is reviewed. Taking note of the surprising semiquantitative success of this description for charm hadrons I interprete the new data on $\tau (D_s)$ and re-iterate the call for more ... More

Memo on Extracting |V(cb)| and |V(ub)/V(cb)| from semileptonic B decaysJul 07 1999Heavy Quark Expansions for semileptonic decays of beauty hadrons are briefly reviewed. I analyze how $|V(cb)|$ can be extracted from the semileptonic width of $B$ mesons, the average semileptonic width of all weakly decaying beauty hadrons and from $B ... More

Inclusive $B_c$ Decays As A QCD LabOct 17 1995Phenomenological models of heavy flavour decays differ significantly in their predictions of global features of $B_c$ decays, like the $B_c$ lifetime or the relative weight of $c\ra s$ and $b\ra c$ transitions. The $1/m_Q$ expansion which is directly ... More

Lifetimes of Heavy-Flavour Hadrons -- Whence and Whither?Jul 21 1995Jul 27 1995A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with ... More

Spectrum of Anisotropic Exponents in Hydrodynamic Systems with PressureNov 14 2000Mar 15 2001We discuss the scaling exponents characterizing the power-law behavior of the anisotropic components of correlation functions in turbulent systems with pressure. The anisotropic components are conveniently labeled by the angular momentum index $\ell$ ... More

Ultra High Energy Cosmic Rays and InflationJan 27 1999Two processes of matter creation after inflation: 1) gravitational creation of superheavy (quasi)stable particles, and 2) non-thermal phase transitions leading to formation of topological defects, may be relevant to the resolution of the puzzle of cosmic ... More

Bridge between Hadrodynamics & HEP: Regional CP Violation in Beauty & Charm DecaysAug 23 2016Oct 03 2016There is a long way from `accuracy' to `precision' about {\bf CP} asymmetries in the decays of beauty \& charm hadrons. (a) We have to apply consistent parametrization of the CKM matrix. (b) Probing many-body final states (FS) is {\em not} a back-up for ... More

Intercalant-Driven Superconductivity in YbC$_{6}$ and CaC$_{6}$Apr 06 2005Recently deiscovered superconductivity in YbC$_6$ and CaC$_6$ at temperatures substantially higher than previously known for intercalated graphites, raised several new questions: (1) Is the mechanism considerably different from the previously known intercalated ... More

Vitaly Ginzburg and High Temperature Superconductivity: Personal ReminiscencesAug 14 2007Aug 17 2007I offer some personal reminiscences from the period of 1976-1983, when I was a M. Sc. and then a Ph.D. student in Vitaly L. Ginzburg's High Temperature Superconductivity group at the P.N. Lebedev Institute in Moscow

Isentropic perturbations of a chaotic domainJan 23 2014Three major properties of the chaotic dynamics of the standard map, namely, the measure \mu of the main connected chaotic domain, the maximum Lyapunov exponent L of the motion in this domain, and the dynamical entropy h = \mu L are studied as functions ... More

On the stability of the triangular libration points: exact resultsAug 30 2007Oct 10 2007This paper has been withdrawn by the author, due to necessity of revision.

Coding for Parallel Channels: Gallager Bounds for Binary Linear Codes with Applications to Repeat-Accumulate Codes and VariationsJul 02 2006This paper is focused on the performance analysis of binary linear block codes (or ensembles) whose transmission takes place over independent and memoryless parallel channels. New upper bounds on the maximum-likelihood (ML) decoding error probability ... More

CP Asymmetries (\& T Violation) in Known Matter -- and beyondNov 03 2014Aug 18 2016Finding \cp~violation (\CPV ) in 1964 produced a real revolution in the fundamental dynamics, although the community did not understand it right away. The paper by Kobayashi \& Maskawa \cite{KM} appeared in 1973 to describe \CPV~in classes of three (or ... More

No Pain, No Gain -- On the Challenges and Promises of Charm StudiesJul 17 2009The observation of $D^0 - \bar D^0$ oscillations has left us in a tantalizing quandary concerning the theoretical interpretation: are they still compatible with the SM or might they require new dynamics (NP)? A comprehensive search for CP violation in ... More

Flavour Dynamics & \cp Violation in the Standard Model: A Crucial Past -- and an Essential FutureJan 31 2007Our knowledge of flavour dynamics has undergone a `quantum jump' since just before the turn of the millenium: direct \cp violation has been firmly {\em established} in $K_L \to \pi \pi$ decays in 1999; the first \cp asymmetry outside $K_L$ decays has ... More

Studying CP Violation -- Chances for a New AllianceJun 26 2002The last three years have seen a phase transition in our knowledge about CP violation: (i) Direct CP violation has been established in $K_L \to \pi \pi$. (ii) The first CP violation outside $K_L$ decays has been observed in $B_d \to \psi K_S$: $<{\rm ... More

The Vietri CodicesJun 23 2002Aug 08 2002Studying heavy flavour physics is driven by multiple motivations: to probe our theoretical control over QCD; enhance our information on gluon and sea quark structure functions; use heavy flavour production as signal for the onset of the quark-gluon plasma; ... More

Charm Physics and the Poor Sleeper's ImpatienceApr 02 2001After a short review of the theoretical tools available to describe heavy flavour physics I sketch the present profile of the weak dynamics of charm hadrons with respect to lifetimes, oscillations and CP violation. I argue that comprehensive studies of ... More

The QCD Perspective on Lifetimes of Heavy-Flavour HadronsAug 31 1995Over the last few years a theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology is described as it applies to total lifetimes, and the underlying theoretical issues are discussed. ... More

Looking from the East at an Elephant Trotting West: Direct CP Violation in $B^0$ DecaysMar 17 2002Mar 24 2002With the time dependant CP asymmetry in $B_d(t) \to \psi K_S$ well measured, the most powerful method to search for {\em direct} CP violation in $B_d$ decays is to analyze whether the CP asymmetry of other transitions like $B_d(t) \to \pi ^+ \pi ^-, \eta ... More

On A Recent Claim Concerning $τ(D_s)/τ(D^0)$Dec 11 2001Feb 06 2002It has been suggested that the observed $D_s - D^0$ lifetime difference can be `understood' as due to $SU(3)_{Fl}$ breaking in the phase spaces for the exclusive $D^0$ and $D_s$ channels `removing' the need for weak annihilation. It is pointed out that ... More

Charm Physics - Like Botticelli in the Sistine ChapelJul 09 2001After sketching heavy quark expansions as applied to heavy flavour decays I emphasize the relevance of nonperturbative dynamics at the charm scale for exclusive $b\to c$ modes. I address the issue of quark-hadron duality for charm and discuss both the ... More

The Expected, The Promised and The Conceivable -- On CP Violation in Beauty and Charm DecaysDec 05 1994the KM expectations of large CP asymmetries in $B$ decays are reviewed. I describe some observable signatures for the intervention of New Physics and list benchmarks defining the `ultimate' measurements in beauty physics. I also stress the need for dedicated ... More

An efficient and flexible Abel-inversion method for noisy dataAug 25 2016We propose an efficient and flexible method for solving Abel integral equation of the first kind, frequently appearing in many fields of astrophysics, physics, chemistry, and applied sciences. This equation represents an ill-posed problem, thus solving ... More

Superconductivity and Magnetism in BiOCuSJan 13 2010Apr 20 2010BiOCu_{1-y}S was recently reported to superconduct at T=5.8 K at y~0.15. Band structure calculations indicate that stoichiometric BiOCuS is a band insulator. In this paper, I show that hole-doped (whether in the virtual crystal approximation or with actual ... More

Absence of magnetic ordering in NiGa_2S_4Aug 09 2007Triangular-layered NiGa2S4, contrary to intuitive expectation, does not form a noncollinear antiferromagnetic structure, as do isoelectronic NaCrO2 and LiCrO2. Instead, the local magnetic moments remain disordered down to the lowest measured temperature. ... More

Electronic structure and magnetism in the frustrated antiferromagnet LiCrO2Jan 22 2007LiCrO2 is a 2D triangular antiferromagnet, isostructural with the common battery material LiCoO2 and a well-known Jahn-Teller antiferromagnet NaNiO2. As opposed to the latter, LiCrO2 exibits antiferromagnetic exchange in Cr planes, which has been ascribed ... More

Tunneling of Bloch electrons through vacuum barrierDec 04 2000Tunneling of Bloch electrons through a vacuum barrier introduces new physical effects in comparison with the textbook case of free (plane wave) electrons. For the latter, the exponential decay rate in the vacuum is minimal for electrons with the parallel ... More

Probing CP Violation in $τ^- \to ν(Kπ/K2π/ 3K/ K3π)^- $ DecaysApr 26 2012Jun 19 2012It had been suggested to probe CP violation in {\tau} \rightarrow {\nu}K{\pi} decays with K0 -K ^{-}0 oscillation to produce ACP({\tau}- \rightarrow {\nu}KS{\pi}-) = (0.36\pm0.01)%. BaBar has found ACP({\tau}- \rightarrow {\nu}KS{\pi}-[\geq {\pi}0]) = ... More

Could Charm's "Third Time" Be the Real Charm? -- A ManifestoFeb 18 2009The recent observation of $D^0 - \bar D^0$ oscillations has left us in a quandary concerning the theoretical interpretation: are they driven by SM forces alone or do they involve new dynamics? A comprehensive analysis of \cp symmetry in $D$ decays can ... More

I Have Come to Praise Charm, not Bury itDec 03 2004The case for further dedicated studies of charm dynamics is presented as driven by three complementary motivations: core lessons on QCD and nonperturbative dynamics in general can be learnt; those can be applied with great profit in analyses of B decays; ... More

CP, T and CPT Symmetries at the Turn of a New MilleniumNov 19 2000After summarizing the status concerning CP violation in 1998 I describe the exciting developments of the last two years and extrapolate to the future. I comment on recent lessons about T and CPT invariance maninly from CPLEAR and emphasize the potential ... More

Flavour Dynamics - Central Mysteries of the Standard ModelSep 04 2000Sep 16 2000After pointing out the amazing success of the CKM description in accommodating the phenomenology of flavour changing neutral currents I review the status of theoretical technologies for extracting CKM parameters from data. I sketch novel directions, namely ... More

Dear Santa: Heavy Flavour Physics at Neutrino Factories - Desires from TheoryJun 21 2000Even in 2010 the CKM parameters $V_{cs}$, $V_{cd}$ and $V_{ub}$ will be known with less than desirable accuracy; the discovery potential for New Physics in charm decays -- in particular their CP asymmetries -- will be far from exhausted; important tests ... More

Marching towards a Theory of Non-leptonic Decays of heavy-Flavour Hadrons"Nov 03 1993Theoretical descriptions for the nonleptonic decays of heavy flavour hadrons have emerged that incorporate non-perturbative corrections in a systematic way and are genuinely based on QCD. One can reproduce $\tau (D^+)/\tau (D^0)$, $BR_{SL}(D^+)$ and $BR_{SL}(D^0)$ ... More

Working with Kolya Uraltsev for twenty-five years about Fundamental Dynamics & Symmetries and for the future -- like CP Violation & EDMsOct 28 2013Feb 25 2015Working with Kolya Uraltsev was a real `marvel' for me about CP & T violation, QCD & its impact on transitions in heavy flavor hadrons, EDMs. The goal was -- and still is -- to define fundamental parameters dynamics, how to measure them and compare SM ... More

"Ceterum censeo Fabricam Super Saporis esse faciendam" ("Moreover I advise a Super-Flavour Factory has to be built")Apr 28 2008The discovery of $B_d - \bar B_d$ oscillations twenty years ago by the ARGUS collaboration marked a watershed event. It persuaded a significant part of the HEP community that the large time dependent \cp asymmetries predicted for some $B_d$ decays might ... More

A Send-off after Dif06: What Do We Need to Know to Understand More?Mar 29 2006After a brief look back at the roles played by hadronic machines and $e^+e^-$ colliders I emphasize that continuing dedicated studies of heavy flavour transitions should be central to our efforts of decoding nature's `Grand Design'. For studies `instrumentalizing' ... More

Astroparticle PhysicsMay 18 2004In this astro-particle lecture course I shall try to emphasize evidence of the new physics which we have in cosmological and astrophysical data. This includes support of the inflationary model, necessity of dark energy and of non-baryonic dark matter, ... More

Phase Transitions at PreheatingOct 19 1995Feb 07 1996Symmetry restoration processes during the non-equilibrium stage of ``preheating'' after inflation is studied. It is shown that symmetry restoration is very efficient when the majority of created particles are concentrated at energies much smaller than ... More

Suppression and restoration of superconductivity in PrBa2Cu3O7Mar 03 1999Mar 11 1999I review the principal experimental findings about superconductivity, suppression thereof, and related properties of RE_{1-x}Pr_xBa_2Cu3O7 in a decision-tree manner, eliminating the models substantially incompatible with established experimental facts, ... More

On the possibility of superconductivity in PrBa2Cu3O7Jun 19 1998Recent reports about observations of superconductivity in PrBa2Cu3O7 raise a number of questions: (i) of various theories striving to explain the Tc suppression in PrxY{1-x}Ba2Cu3O7, are there any compatible with possible superconductivity in stoichiometric ... More

Symmetry analysis of possible superconducting states in KxFe2Se2 superconductorsFeb 17 2011A newly discovered family of the Fe-based superconductors is isostructural with the so-called 122 family of Fe pnictides, but has a qualitatively different doping state. Early experiments indicate that superconductivity is nodeless, yet prerequisites ... More

Sr$_{2}$VO$_{3}$FeAs as Compared to Other Fe-based SuperconductorsSep 28 2009Apr 20 2010One of the most popular scenarios for the superconductivity in Fe-based superconductors (FeBSC) posits that the bosons responsible for electronic pairing are spin-fluctuations with a wave vector spanning the hole Fermi surfaces (FSs) near $\Gamma$ and ... More

Role of defects on the electronic and magnetic properties of CrAs/InAs and CrAs/CdSe half-metallic interfacesDec 09 2009We present an extended study of single impurity atoms at the interface between the half-metallic ferromagnetic zinc-blende CrAs compound and the zinc-blende binary InAs and CdSe semiconductors in the form of very thin multilayers. Contrary to the case ... More

Symbolic computation of the Birkhoff normal form in the problem of stability of the triangular libration pointsDec 26 2013The problem of stability of the triangular libration points in the planar circular restricted three-body problem is considered. A software package, intended for normalization of autonomous Hamiltonian systems by means of computer algebra, is designed ... More

RXTE observations of Seyfert-2 galaxies: evidence for spectral variabilityAug 18 2000We present a series of RXTE observations of the nearby obscured Seyfert galaxies ESO103-G35, IC5063, NGC4507 and NGC7172. The period of monitoring ranges from seven days for NGC7172 up to about seven months for ESO103-G035. The spectra of all galaxies ... More

CP Asymmetries in Many-Body Final States in Beauty & Charm TransitionsSep 13 2015Dec 06 2015Our community has focused on two-body final states in $B$ & $D$ decays. The SM produces at least the leading source of CP violation in $B$ transitions, none has been established yet in charm decays. It is crucial to measure three- and four-body FS with ... More

Hadronization -- the Unsung Hero rather than the Alleged Villain in the Tale of CP ViolationSep 14 2005The novel successes scored by the Standard Model of High Energy Physics in the last few years concerning heavy flavour dynamics do not weaken the case for `New Physics' around the TeV scale. They do suggest however that one cannot {\em count} on that ... More

`Per Aspera Ad Astra' -- A Short Essay on the Long Quest for CP ViolationNov 10 2004After briefly explaining the special role played by violations of CP and T invariance and their connection with the baryon number of the Universe, I sketch the history of CP violation studies since its totally unexpected discovery in 1964. For about 30 ... More

3- and 4-Body Final States in B, D and tau Decays about Features of New Dynamics with CPT Invariance or "Achaeans outside Troy"Jun 25 2013Aug 08 2013The 'landscape' of fundamental dynamics has changed even for the 'known' matter. The Standard Model has produced at least the leading source of CP violation (CPV) in B decays; the data have not shown CP asymmetries in $D$ transitions. It needs more data ... More

CP Violation in $τ$ Decays at SuperB \& Super-Belle Experiments -- like Finding Signs of Dark MatterOct 10 2012BaBar has found $A_{\rm CP}(\tau^- \to \nu K_S\pi^- [\geq \pi^0]) = (-0.36 \pm 0.23 \pm 0.11)%$ with 2.8 $\sigma$ difference with SM prediction $A_{\rm CP}(\tau^- \to \nu K_S\pi^-) = (0.36 \pm 0.01)%$ based on $K^0 - \bar K^0$ oscillation. Four central ... More

"I Know She Invented Fire, But What Has She Done Recently?" -- On The Future Of Charm PhysicsAug 07 2006Detailed studies of weak charm decays fill an important {\em future} role in high energy physics. Chief among them are: (i) validating the theoretical control achieved over hadronization as a worthwhile goal in its own right; (ii) calibrating our tools ... More

Flavour Dynamics & CP Violation in the SM*: A Tale in Five Parts of Great Successes, Little Understanding -- and Promise for the Future!Jan 20 2006Our knowledge of flavour dynamics has undergone a `quantum jump' since just before the turn of the millenium: direct \cp violation has been firmly {\em established} in $K_L \to \pi \pi$ decays in 1999; the first \cp asymmetry outside $K_L$ decays has ... More

InflationDec 10 2001Inflationary cosmology is reviewed. Particular attention is given to processes of creation.

A study of the effects of preheatingJan 24 1997We review results of a numerical study of resonant inflaton decay in a wide range of realistic models and parameters. Wide enough parametric resonance can withstand the expansion of the Universe, though account for the expansion is very important for ... More

Mossbauer Spectroscopy Determination of iron foreign phases in the Superconducting Systems; RAsFeO1-x, RAsFeO1-xFx and Sr1-xKxFe2As2Jun 25 2008The recently discovered superconducting - spin density wave materials, containing Fe and As, have raised huge interest. However most materials prepared to date, suffer from a varying degree of content of foreign Fe-As phases, Fe2As, FeAs2 and FeAs, which ... More

CaMn$_{2}$Sb$_{2}:$ a fully frustrated classical magnetic systemSep 15 2013We show by means of density functional calculations that CaMn$_{2}$Sb$_{2}$ is very close to a mean-field critical point known for the classical Heisenberg model on the honeycomb lattice. Three entirely different long range ordered magnetic phases become ... More

Correspondence on "Electronic correlations in the iron pnictides"Oct 21 2009I point out that the observed discrepancy between the measured and calculated Drude weights in LaFePO may be caused not only by mass renormalization, but also by a DFT inaccuracy in determining the relative positions of the hole and electron band.

How to calculate the degree of spin polarization in ferromagnets?Dec 19 1998Jun 10 1999Different ways to define and to calculate the degree of spin polarization in a ferromagnet are discussed, particularly with respect to spin-polarized tunneling and Andreev reflection at the boundary between a superconductor and ferromagnet. As an example, ... More

Structural and Electronic Properties of the 2D Superconductor CuS with 1 1/3-valent CopperNov 03 2011Jan 13 2012We present first principle calculations of the structural and electronic properties of the CuS covellite material. Symmetry-lowering structural transition is well reproduced. However, the microscopic origin of the transition is unclear. The calculations ... More

CeMnNi4: an impostor half-metalOct 14 2005Recent experiments show CeMnNi$_{4}$ to have a nearly integer magnetic moment and a relatively large transport spin polarization, as probed by Andreev reflection, suggesting that the material is a half metal or close to it. However, the calculations reported ... More

Testing the wavelength dependence of cosmological redshift down to $Δz \sim 10^{-6}$May 30 2016At the core of the standard cosmological model lies the assumption that the redshift of distant galaxies is independent of photon wavelength. This invariance of cosmological redshift with wavelength is routinely found in all galaxy spectra with a precision ... More

Lyapunov exponents in resonance multipletsDec 19 2013The problem of estimating the maximum Lyapunov exponents of the motion in a multiplet of interacting nonlinear resonances is considered for the case when the resonances have comparable strength. The corresponding theoretical approaches are considered ... More

The dynamical temperature and the standard mapDec 19 2013Numerical experiments with the standard map at high values of the stochasticity parameter reveal the existence of simple analytical relations connecting the volume and the dynamical temperature of the chaotic component of the phase space.

Rectangles in latin squaresFeb 13 2019To get another from a given latin square, we have to change at least 4 entries. We show how to find these entries and how to change them.

"I Know She Invented Fire, but What Has She Done Recently?" or "I Have Come to Praise Ch., not Bury Her!" or `On the Second Renaissance of Charm Physics'Aug 13 2008$D^0$ oscillations, for which the $B$ factories have found strong evidence, provide a new stage for our search for New Physics in heavy flavour dynamics. While the theoretical verdict on the observed values of $x_D$ and $y_D$ is ambiguous -- they could ... More

The Unreasonable Success of CKM TheoryJan 11 2005CKM theory has scored novel successes recently, namely vindication of weak universality and its first decisive test in CP studies. While this does not weaken the case for New Physics, one cannot count on the latter to induce large discrepancies in future ... More

CP Violation and the Cathedral Builders' ParadigmNov 02 2000Nov 16 2000Pointing out the profound and unique nature of CP violation, I sketch its basic phenomenology, its CKM prescription and QCD technologies relevant for heavy flavour physics. After emphasizing the paradigmatic character of the establishment of direct CP ... More

Treating the Lifetimes of Charm and Beauty Hadrons with QCD Plus a Bit More!Jun 21 1996The heavy quark expansion implemented through an operator product expansion provides us with a treatment of inclusive decays of beauty and charm hadrons that is genuinely derived from QCD,though it requires one additional assumption, namely that of 'local' ... More

Open Questions in Charm Decays Deserving an AnswerAug 04 1994A list is given of those open questions concerning the dynamics of charm decays where there exists a strong need for an answer. Such a need is based on lessons to be learnt about QCD -- either in their own right or for a better understanding of $B$ physics ... More

Probing CP Asymmetries in Charm Baryons DecaysJun 20 2012With the first evidence of direct CP violation in $D^0 \to K^+K^-/\pi^+\pi^-$ there is a strong reason to probe CP asymmetries in charm baryons in three-body final states $\Lambda_c \to p\pi^+\pi^-/pK^+K^-$ & $\Lambda_c \to pK^+\pi^-$ with $\Lambda_c ... More

CP Violation in the SM, Quantum Subtleties and the Insights of Yogi BerraMar 13 2007May 10 2007Our knowledge of flavour dynamics has undergone a `quantum jump' since just before the turn of the millenium: direct CP violation has been firmly established in $K_L \to \pi \pi$ decays in 1999; the first CP asymmetry outside $K_L$ decays has been discovered ... More

CP Violation in Beauty Decays -- the Standard Model Paradigm of Large EffectsJul 06 1994The Standard Model contains a natural source for CP asymmetries in weak decays, which is described by the KM mechanism. Beyond $\epsilon _K$ it generates only elusive manifestations of CP violation in {\em light-}quark systems. On the other hand it naturally ... More

Anomalous Scaling in Passive Scalar Advection and Lagrangian Shape DynamicsJan 30 2000The problem of anomalous scaling in passive scalar advection, especially with $\delta$-correlated velocity field (the Kraichnan model) has attracted a lot of interest since the exponents can be computed analytically in certain limiting cases. In this ... More

Unsupervised spectral decomposition of X-ray binaries with application to GX 339-4Dec 16 2014Jan 21 2015In this paper we explore unsupervised spectral decomposition methods for distinguishing the effect of different spectral components for a set of consecutive spectra from an X-ray binary. We use well-established linear methods for the decomposition, namely ... More

Robust half-metallicity and metamagnetism in Fe_{x}Co_{1-x}S_{2}Feb 04 2000The Fe_{x}Co_{1-x}S_{2} system is predicted, on the basis of density functional calculations, to be a half metal for a large range of concentrations. Unlike most known half metals, the half metallicity in this system should be very stable with respect ... More

Equation of state and magnetic susceptibility of spin polarized isospin asymmetric nuclear matterMar 22 2002Properties of spin polarized isospin asymmetric nuclear matter are studied within the framework of the Brueckner--Hartree--Fock formalism. The single-particle potentials of neutrons and protons with spin up and down are determined for several values of ... More

The Dynamics of Beauty & Charm Hadrons and top quarks in the Era of the LHCb & Belle II and ATLAS/CMS, Motto: Non-perturbative QCD \& Many-body Final StatesJan 30 2018Our community has to apply {\em non}-perturbative QCD on different levels of flavor dynamics in strange, charm \& beauty hadrons and even for top quarks. We need {\em consistent} parameterization of the CKM matrix and describe weak decays of beauty hadrons ... More

Study of $e^+ e^- \to p \bar p$ via initial state radiation at BESIIIFeb 02 2019The Born cross section for the process $e^+ e^- \to p \bar p $ is measured using the initial state radiation technique with an undetected photon. This analysis is based on data sets corresponding to an integrated luminosity of 7.4 fb$^{-1}$, collected ... More

Amplitude Analysis and Branching Fraction Measurement of $D^0\rightarrow K^-π^+π^0π^0$Mar 15 2019Utilizing the dataset corresponding to an integrated luminosity of $2.93$ fb$^{-1}$ at $\sqrt{s}=3.773$ GeV collected by the BESIII detector, we report the first amplitude analysis and branching fraction measurement of the $D^0\rightarrow K^-\pi^+\pi^0\pi^0$ ... More