Results for "N. Grittini"

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Zeros of irreducible characters lying in a normal subgroupFeb 08 2019Let $N$ be a normal subgroup of a finite group $G$. An element $g\in G$ such that $\chi(g)=0$ for some irreducible character $\chi$ of $G$ is called a vanishing element of $G$. The aim of this paper is to analyse the influence of the $\pi$-elements in ... More
On zeros of irreducible characters lying in a normal subgroupFeb 08 2019Feb 13 2019Let $N$ be a normal subgroup of a finite group $G$. An element $g\in G$ such that $\chi(g)=0$ for some irreducible character $\chi$ of $G$ is called a vanishing element of $G$. The aim of this paper is to analyse the influence of the $\pi$-elements in ... More
SN 2011ht: Weak explosion in massive extended envelopeOct 21 2015Oct 29 2015A possibility is explored to account for the light curve and the low expansion velocity of the supernova SN~2011ht, a member of group of three objects showing signatures of both IIn and IIP supernovae. It is argued that the radiated energy and the expansion ... More
Affine metrics and algebroid structures: Application to general relativity and unificationAug 14 2011Affine metrics and its associated algebroid bundle are developed. Theses structures are applied to the general relativity and provide an structure for unification of gravity and electromagnetism. The final result is a field equation on the associated ... More
$ΔS = 1$ Hadronic Weak Decays of Hyperons in a Soliton ModelSep 23 1997We study the parity violating hyperon non-leptonic weak decays in the three flavor Skyrme model. We follow the approach in which the symmetry breaking terms in the action are diagonalized exactly within the collective coordinate approximation. We show ... More
Fate of k_perp-factorization for hard processes in nuclear environmentDec 15 2004Large thickness of heavy nuclei brings in a new scale into the pQCD description of hard processes in nuclear environment. The familiar linear $k_{\perp}$-factorization breaks down and must be replaced by a new concept of the nonlinear $k_{\perp}$-factorization ... More
Random data Cauchy theory for supercritical wave equations I: Local theoryJul 10 2007We study the local existence of strong solutions for the cubic nonlinear wave equation with data in $H^s(M)$, $s<1/2$, where $M$ is a three dimensional compact riemannian manifold. This problem is supercritical and can be shown to be strongly ill-posed ... More
Asymmetry of $^{56}$Ni ejecta and polarization in type IIP supernova 2004djAug 21 2006I study a problem, whether the asymmetry of a $^{56}$Ni ejecta that results in the asymmetry of the H$\alpha$ emission line at the nebular epoch of the type IIP supernova SN 2004dj is able also to account for the recently detected polarization of the ... More
Non-Abelian Lovelock-Born-Infeld Topological Black HolesSep 02 2009Oct 24 2009We present the asymptotically AdS solutions of the Einstein gravity with hyperbolic horizons in the presence of $So(n(n-1)/2-1, 1)$ Yang-Mills fields governed by the non-Abelian Born-Infeld lagrangian. We investigate the properties of these solutions ... More
Gaussian measures associated to the higher order conservation laws of the Benjamin-Ono equationSep 24 2011Jul 04 2012Inspired by the work of Zhidkov on the KdV equation, we perform a construction of weighted gaussian measures associated to the higher order conservation laws of the Benjamin-Ono equation. The resulting measures are supported by Sobolev spaces of increasing ... More
Stability of the Lepton-Flavor Mixing Matrix Against Quantum CorrectionsJun 24 1999Recent neutrino experiments suggest the strong evidences of tiny neutrino masses and the lepton-flavor mixing. Neutrino-oscillation solutions for the atmospheric neutrino anomaly and the solar neutrino deficit can determine the texture of neutrino mass ... More
Yukawa Interaction from a SUSY Composite ModelSep 04 1997We present a composite model that is based on non-perturbative effects of N=1 supersymmetric SU(N_C) gauge theory with N_f=N_C+1 flavors. In this model, we consider N_C=7, where all matter fields in the supersymmetric standard model, that is, quarks, ... More
Static Configurations of Dark Energy and Dark MatterSep 26 2005Dec 08 2005We study static configurations of dark matter coupled to a scalar field responsible for the dark energy of the Universe. The dark matter is modelled as a Fermi gas within the Thomas-Fermi approximation. The mass of the dark matter particles is a function ... More
Colour transparency: a novel test of QCD in nuclear interactionsApr 20 1993Colour transparency is a cute and indispensable property of QCD as the gauge theory of strong interaction. CT tests of QCD consist of production of the perturbative small-sized hadronic state and measuring the strngth of its non-perturbative diffraction ... More
Intrinsic $k_{\perp}$ in the pomeronMay 31 1999Aug 20 1999In a consistent QCD approach to diffractive DIS gluons in the pomeron have soft $z_{g}$ distribution and very broad intrinsic $k_{\perp}$ distribution. The latter has not yet been incorporated into diffractive Monte-Carlo generators (RAPGAP,....). I argue ... More
Invariant measure for a three dimensional nonlinear wave equationJul 10 2007We study the long time behavior of the subcritical (subcubic) defocussing nonlinear wave equation on the three dimensional ball, for random data of low regularity. We prove that for a large set of radial initial data in $\cap_{s<1/2} H^s(B(0,1))$ the ... More
An example of a 16-vertex Folkman edge (3,4)-graph without 8-cliquesFeb 12 2006In this paper we prove a new upper bouhd on an edge Folkman number. In a previous paper we have proved that this bound is exact.
Modified Gauss-Newton method in low-rank signal estimationMar 04 2018The paper is devoted to the solution of a weighted non-linear least-squares problem for low-rank signal estimation, which is related Hankel structured low-rank approximation problems. The solution is constructed by a modified weighted Gauss-Newton method. ... More
Effective quantum number for axially symmetric problemsAug 15 2014We generalize the universal effective quantum number introduced earlier for centrally symmetric problems. The proposed number determines the semiclassical quantization condition for axially symmetric potentials.
Propagation of a Dark Soliton in a Disordered Bose-Einstein CondensateJun 01 2005Sep 26 2005We consider the propagation of a dark soliton in a quasi 1D Bose-Einstein condensate in presence of a random potential. This configuration involves nonlinear effects and disorder, and we argue that, contrarily to the study of stationary transmission coefficients ... More
Unnatural Oscillon Lifetimes in an Expanding BackgroundApr 19 2006Jul 11 2006We consider a classical toy model of a massive scalar field in 1+1 dimensions with a constant exponential expansion rate of space. The nonlinear theory under consideration supports approximate oscillon solutions, but they eventually decay due to their ... More
Non-linear Matter Spectrum for a Variable Equation of StateFeb 17 2010Apr 10 2014We study the growth of matter perturbations beyond the linear level in cosmologies in which the dark energy has a variable equation of state. The non-linear corrections result in shifts in the positions of the maximum, minima and nodes of the spectrum ... More
Unifying aspects of polarization of vector mesons from hard production in DIS and at TevatronAug 08 2001Virtual photons have both the transverse and longitudinal polarization. In the inclusive DIS the impact of longitudinal photons, quantified by R=sigmaL/\igmaT sim 0.2, is marginal, but in diffractive DIS with excitation of small mass hadronic states or ... More
Incomplete Tribonacci-Lucas numbers and polynomialsApr 16 2014In this paper, we define Tribonacci-Lucas polynomials and present Tribonacci-Lucas numbers and polynomials as a binomial sum. Then, we introduce incomplete Tribonacci-Lucas numbers and polynomials. In addition we derive recurrence relations, some properties ... More
Cohomological invariants of a variation of flat connectionApr 20 2015Sep 23 2015In this paper, we apply the theory of Chern-Cheeger-Simons to construct canonical invariants associated to a $r$-simplex whose points parametrize flat connections on a smooth manifold $X$. These invariants lie in degrees $(2p-r-1)$-cohomology with $C/Z$-coefficients, ... More
Stability of tangent bundle on the moduli space of stable bundles on a curveNov 01 2011Feb 12 2014In this paper, we prove that the tangent bundle of the moduli space $\cSU_C(r,d)$ of stable bundles of rank $r>2$ and of fixed determinant of degree $d$ (such that $(r,d)=1$), on a smooth projective curve $C$ is always stable, in the sense of Mumford-Takemoto. ... More
Random data Cauchy theory for supercritical wave equations II : A global existence resultJul 10 2007We prove that the subquartic wave equation on the three dimensional ball $\Theta$, with Dirichlet boundary conditions admits global strong solutions for a large set of random supercritical initial data in $\cap_{s<1/2} H^s(\Theta)$. We obtain this result ... More
Chern invariants of some flat bundles in the arithmetic Deligne cohomologyApr 09 2006In this note, we investigate the Chern classes of flat bundles in the arithmetic Deligne Cohomology, introduced by Green-Griffiths, Asakura-Saito. We show nontriviality of the Chern classes in some cases and the proof also indicates that generic flat ... More
Bosonic stimulation of cold 1s excitons into a harmonic potential minimum in Cu$_2$OFeb 07 2003Density distribution of cold exciton clouds generated into a strain-induced potential well by two-photon excitation in Cu$_2$O is studied at 2 K. We find that an anomalous spike, which can be interpreted as accumulation of the excitons into the ground ... More
The Universal Equation of State near the Critical Point of QCDJan 12 2004Jun 18 2004We study the universal properties of the phase diagram of QCD near the critical point using the exact renormalization group. For two-flavour QCD and zero quark masses we derive the universal equation of state in the vicinity of the tricritical point. ... More
Analytical Estimate of the Effect of Spherical Inhomogeneities on Luminosity Distance and RedshiftFeb 06 2008Jun 25 2008We provide an analytical estimate of the effect of a spherical inhomogeneity on light beams that travel through it. We model the interior of the inhomogeneity in terms of the Lemaitre-Tolman-Bondi metric. We assume that the beam source is located outside ... More
Heavy quark skyrmionsMay 18 2009The description of the heavy baryons as heavy-meson--soliton bound systems is reviewed. We outline how such bound systems arise from effective lagrangians that respect both chiral symmetry and heavy quark symmetry. Effects due to finite heavy quark masses ... More
Wind of presupernova IIn SN~1997egJan 15 2019Spectra and phototometry of type IIn supernova SN 1997eg are used to determine properties of the circumstellar gas lost by the presupernova during the latest 200 years before the explosion. The analysis of narrow H$\alpha$ and [Fe X] 6374 \AA\ results ... More
Upgrading the Local Ergodic Theorem for planar semi-dispersing billiardsMay 29 2007Jun 04 2009The Local Ergodic Theorem (also known as the `Fundamental Theorem') gives sufficient conditions under which a phase point has an open neighborhood that belongs (mod 0) to one ergodic component. This theorem is a key ingredient of many proofs of ergodicity ... More
Connection between Diffraction and Small-$x$Nov 30 2001A brief review of the modern QCD theory of diffractive DIS is given.
Diffractive DIS: Where Are We?Nov 12 2001Nov 20 2001A brief review of the modern QCD theory of diffractive DIS is given. The recent progress has been remarkably rapid, all the principal predictions from the color dipole approach to diffraction - the $(Q^2+m_V^2)$ scaling, the pattern of SCHNC, shrinkage ... More
Diffractive Vector Mesons in DIS: Meson Structure and QCDSep 15 2000I review the modern status of QCD theory of diffractive vector meson production with the focus on shrinkage of photons with Q2 and (Q2+mV2)$scaling, j-plane properties of the QCD pomeron and Regge shrinkage of diffraction cone, $s$-channel helicity non-conservation ... More
Spin dependence of diffractive DISMay 31 1999I review the recent progress in the theory of s-channel helicity nonconservation (SCHNC) effects in diffractive DIS including the unitarity driven demise of the Burkhardt-Cottingham sum rule and strong scaling departure from the Wandzura-Wilczek relation. ... More
New upper bound for a class of vertex Folkman numbersJan 11 2006We improve the previuosly known bound for some vertex Folkman numbers.
Flow-invariant hypersurfaces in semi-dispersing billiardsMar 15 2006This work results from our attempts to solve Boltzmann-Sinai's hypothesis about the ergodicity of hard ball gases. A crucial element in the studies of the dynamics of hard balls is the analysis of special hypersurfaces in the phase space consisting of ... More
Henon-Heiles Hamiltonian for Coupled Upper-Hybrid and Magnetoacoutic Waves in Magnetized PlasmasJul 24 1995We show that the coupled mode equations for the stationary propagation of upper--hybrid and magnetoacoustic waves in magnetized electron--ion plasmas with negative group dispersion can be exactly derived from the generalized \Henon--Heiles Hamiltonian. ... More
Circumstellar Na I and Ca II lines of type Ia supernovae in symbiotic scenarioJan 29 2008Formation of circumstellar lines of Na I and Ca II in type Ia supernovae is studied for the case, when supernova explodes in a binary system with a red giant. The model suggests a spherically-symmetric wind and takes into account ionization and heating ... More
Broad emission lines from opaque electron-scattering environment of SN 1998SJun 13 2001I propose that broad narrow-topped emission lines with full width at zero intensity >20000 km/s, seen in early-time spectra of SN 1998S, originate from a dense circumstellar gas and not from the supernova ejecta. The tremendous line width is the result ... More
Circumstellar interaction in type Ibn supernovae and SN 2006jcAug 05 2009I analyse peculiar properties of light curve and continua of enigmatic Ibn supernovae, including SN 2006jc, and argue in favour of the early strong circumstellar interaction. This interaction explains the high luminosity and fast flux rise of SN 1999cq, ... More
Light Scalar Mesons as Manifestation of Spontaneously Broken Chiral SymmetryJan 20 2010Attention is paid to the production mechanisms of light scalars that reveal their nature. We reveal the chiral shielding of the \sigma(600) meson. We show that the kaon loop mechanism of the \phi radiative decays, ratified by experiment, points to the ... More
Strong decays of P wave baryons in the $1/N_c$ expansionApr 18 2005The hadronic decays of non-strange negative parity baryons are analyzed in the framework of the 1/Nc expansion. A complete basis of spin-flavor operators for the pseudoscalar meson S and D partial wave amplitudes is established to order 1/Nc and the unknown ... More
Two and Three parametric regular generalizations of spherically symmetric and axially symmetric metricsNov 22 2002Regular generalizations of spherically and axially symmetric metrics and their properties are considered. Newton gravity law generalizations are reduced for null geodesic.
Stripes ordering in self-stratification experiments of binary and ternary granular mixturesApr 25 2000The self-stratification of binary and ternary granular mixtures has been experimentally investigated. Ternary mixtures lead to a particular ordering of the strates which was not accounted for in former explanations. Bouncing grains are found to have an ... More
Partition test and sexual motivation in male miceAug 02 2007Theoretical analysis of own and literature investigations of sexual motivation with the use of the partition test [Kudryavtseva, 1987, 1994] in male mice was carried out. It has been shown that appearance of a receptive female in the neighboring compartment ... More
Spin Dependence of Diffractive Vector Meson ProductionAug 24 1999Aug 26 1999I review the recent progress in the theory of s-channel helicity nonconservation (SCHNC) effects in diffractive DIS. SCHNC in diffractive vector meson production is an unique probe of the spin-orbit coupling and Fermi motion of quarks in vector mesons. ... More
Helicity Flip in Diffractive DISAug 26 1999I review new results on s-channel helicity nonconservation (SCHNC) in diffractive DIS. I discuss how by virtue of unitarity diffractive DIS gives rise to spin structure functions which were believed to vanish at x << 1. These include tensor polarization ... More
Asymptotic behaviour of the total cross section of p-p scattering and the Akeno cosmic ray dataApr 21 1993I present a new determination of the total cross section for proton-proton collisions from the recent Akeno results on absorption of the cosmic ray protons in the p-Air collisions. Extrapolation to the SSC energy suggests $\sigma_{tot}(p-p) \approx (160-170) ... More
Astrometric and photometric initial mass functions from the UKIDSS Galactic Clusters Survey: I The PleiadesApr 12 2012We present the results of a deep wide-field near-infrared survey of the entire Pleiades cluster recently released as part of the UKIRT Infrared Deep Sky (UKIDSS) Galactic Clusters Survey (GCS) Data Release 9 (DR9). We have identified a sample of ~1000 ... More
Decay $X(3872)\toπ^0π^+π^-$ and $S$-wave $D^0\bar D^0 \toπ^+π^-$ scattering lengthApr 04 2019The isospin-breaking decay $X(3872)\to(D^*\bar D+ \bar D^*D) \to\pi^0D\bar D\to\pi^0\pi^+\pi^-$ is discussed. In its amplitude there is a triangle logarithmic singularity, due to which the dominant contribution to $BR(X(3872)\to\pi^0\pi^+\pi^-)$ comes ... More
Proposal to look for the anomalous isotopic symmetry breaking in central diffractive production of the $f_1(1285)$ and $a^0_0(980)$ resonances at the LHCJan 29 2018Mar 30 2018At very high energies, and in the central region ($x_F\simeq0$), the double-Pomeron exchange mechanism gives the dominant contribution to the production of hadrons with the positive $C$ parity and isospin $I=0$. Therefore, the observation of resonances ... More
Spherical symmetric charged solution with cosmological constantNov 29 2007A spherically symmetric charged ideal fluid solution of Einstein field equation is given in the presence of the cosmological constant and two well known example of this type of solution is presented. If the matter is confined in a region, the exterior ... More
Survey of Gravity in Non-Commutative GeometryApr 28 2009We present a survey of the application of Cones' Non-Commutative Geometry to gravitation. Bases of the theory and Euclidian gravity models are reviewed. Then we discuss the problem of a Lorentzian generalization of the theory and review existing attempts ... More
Unified Model of Radio and X-Ray Emission of Nova CI Cam 1998Sep 08 2010A unified model is proposed for the radio and X-ray outburst of nova CI Cam 1998 which suggests the shock interaction of nova shell with the circumstellar gas. The spherical model is able to describe kinematics of the radio shell together with the evolution ... More
Combined SM Higgs Limits at the TevatronOct 18 2009We combine results from CDF and DO on direct searches for a standard model (SM) Higgs boson (H) in pbar-p collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. Compared to the previous Higgs Tevatron combination, more data and new channels (WH to tau ... More
Nonperturbative renormalization-group approach to fermion systems in the two-particle-irreducible effective action formalismOct 18 2013Jan 24 2014We propose a nonperturbative renormalization-group (NPRG) approach to fermion systems in the two-particle-irreducible (2PI) effective action formalism, based on an exact RG equation for the Luttinger-Ward functional. This approach enables us to describe ... More
Effective action for superfluid Fermi systems in the strong-coupling limitDec 21 2004Oct 20 2005We derive the low-energy effective action for three-dimensional superfluid Fermi systems in the strong-coupling limit, where superfluidity originates from Bose-Einstein condensation of composite bosons. Taking into account density and pairing fluctuations ... More
Spin waves in the spiral phase of a doped antiferromagnet: a strong-coupling approachMay 03 2001We study spin fluctuations in the spiral phase of the two-dimensional Hubbard model at low doping on the basis of the spin-particle-hole coherent-state path integral. In the strong correlation limit, we obtain an analytical expression of the spin-wave ... More
Fermi liquid theory: a renormalization group point of viewApr 30 1996We show how Fermi liquid theory results can be systematically recovered using a renormalization group (RG) approach. Considering a two-dimensional system with a circular Fermi surface, we derive RG equations at one-loop order for the two-particle vertex ... More
$Ω^-$ Hyperon Decay Modes with the HyperCP Experiment at FermilabAug 16 2002The HyperCP experiment (Fermilab E871) has the largest recorded sample of $\Omega^-$ hyperon decays, allowing new searches for three rare decay modes, each with five charged tracks in the final state. Results are presented for $\Omega^-\to\Xi^-\pi^+\pi^-$; ... More
Neutral Hyperon and H-Dibaryon Results from KTeVNov 12 2000Results from the KTeV experiment at Fermilab using neutral Xi hyperons are presented, especially the first form-factor (FF) measurement from its semi-leptonic decay. This decay, which is an important test of the Standard Model, was observed for the first ... More
The Magellanic System: What have we learnt from FUSE?Dec 20 2008I review some of the findings on the Magellanic System produced by the Far Ultraviolet Spectroscopic Explorer (FUSE) during and after its eight years of service. The Magellanic System with its high-velocity complexes provides a nearby laboratory that ... More
Pulsar bow-shock nebulae. II. Hydrodynamical simulationMar 28 2002We present hydrodynamical simulations, using a 2-D two component model (ambient medium and pul sar wind have different specific heat ratios), of bow shocks in a representative regime for pu lsar wind driven bow-shock nebulae. We also investigate the behaviour ... More
Review of the Theory of PWNeNov 22 2013Pulsar Wind Nebulae (PWNe) are ideal astrophysical laboratories where high energy relativistic phenomena can be investigated. They are close, well resolved in our observations, and the knowledg derived in their study has a strong impact in many other ... More
On the Lie subalgebra of Killing-Milne and Killing-Cartan vector fields in Newtonian space-timeDec 18 2014The Galilean (and more generally Milne) invariance of Newtonian theory allows for Killing vector fields of a general kind, whereby the Lie derivative of a field is not required to vanish but only to be cancellable by some infinitesimal Galilean (respectively ... More
Evolutionary games on the lattice: Payoffs affecting birth and death ratesFeb 01 2013May 18 2015This article investigates an evolutionary game based on the framework of interacting particle systems. Each point of the square lattice is occupied by a player who is characterized by one of two possible strategies and is attributed a payoff based on ... More
Chiral four-body interactions in nuclear matterSep 20 2012An exploratory study of chiral four-nucleon interactions in nuclear and neutron matter is performed. The leading-order terms arising from pion-exchange in combination with the chiral $4\pi$-vertex and the chiral NN$3\pi$-vertex are found to be very small. ... More
Isovector part of nuclear energy density functional from chiral two- and three-nucleon forcesMar 28 2012A recent calculation of the nuclear energy density functional from chiral two- and three-nucleon forces is extended to the isovector terms pertaining to different proton and neutron densities. An improved density-matrix expansion is adapted to the situation ... More
Exact calculation of three-body contact interaction to second orderMar 28 2012For a system of fermions with a three-body contact interaction the second-order contributions to the energy per particle $\bar E(k_f)$ are calculated exactly. The three-particle scattering amplitude in the medium is derived in closed analytical form from ... More
Resummation of fermionic in-medium ladder diagrams to all ordersFeb 10 2011A system of fermions with a short-range interaction proportional to the scattering length $a$ is studied at finite density. At any order $a^n$, we evaluate the complete contributions to the energy per particle $\bar E(k_f)$ arising from combined (multiple) ... More
Radiative corrections to neutral pion-pair productionAug 04 2010We calculate the one-photon loop radiative corrections to the neutral pion-pair photoproduction process $\pi^-\gamma \to \pi^-\pi^0\pi^0$. At leading order this reaction is governed by the chiral pion-pion interaction. Since the chiral $\pi^+\pi^-\to\pi^0\pi^0$ ... More
Nuclear energy density functional from chiral pion-nucleon dynamics: Isovector termsMar 04 2010We extend a recent calculation of the nuclear energy density functional in the framework of chiral perturbation theory by computing the isovector surface and spin-orbit terms: $(\vec \nabla \rho_p- \vec \nabla \rho_n)^2 G_d(\rho)+ (\vec \nabla \rho_p- ... More
Pion-photon exchange nucleon-nucleon potentialsJan 31 2006We calculate in chiral perturbation theory the dominant next-to-leading order correction to the $\pi\gamma$-exchange NN-potential proportional to the large isovector magnetic moment $\kappa_v = 4.7$ of the nucleon. The corresponding spin-spin and tensor ... More
Dark matter vs. Pulsars: Catching the impostorSep 13 2013Sep 18 2013Evidence of excess GeV emission nearly coinciding with the Galactic Centre has been interpreted as a possible signature of annihilating dark matter. In this paper, we argue that it seems too early to discard pulsars as a viable explanation for the observed ... More
A Curious Source of Extended X-ray Emission in the Outskirts of Globular Cluster GLIMPSE-C01Nov 13 2009We report the discovery of an unusual source of extended X-ray emission CXOU J184846.3-013040 (`The Stem') located on the outskirts of the globular cluster GLIMPSE-C01. No point-like source falls within the extended emission which has an X-ray luminosity ... More
Spectral functions of isoscalar scalar and isovector electromagnetic form factors of the nucleon at two-loop orderFeb 24 2003We calculate the imaginary parts of the isoscalar scalar and isovector electromagnetic form factors of the nucleon up to two-loop order in chiral perturbation theory. Particular attention is paid on the correct behavior of Im $\sigma_N(t)$ and Im $G_{E,M}^V(t)$ ... More
Chiral corrections to the isovector double scattering term for the pion-deuteron scattering lengthMar 01 2002Mar 06 2002The empirical value of the real part of the pion-deuteron scattering length can be well understood in terms of the dominant isovector $\pi N$-double scattering contribution. We calculate in chiral perturbation theory all one-pion loop corrections to this ... More
The Reaction $pp\to p ΛK^+$ Near ThresholdFeb 19 1999We analyze the recent total cross section data for $pp \to p\Lambda K^+$ near threshold measured at COSY. Using an effective range approximation for the on-shell $p\Lambda$ S-wave final state interaction we extract from these data the combination ${\cal ... More
Quartic isospin asymmetry energy of nuclear matter from chiral pion-nucleon dynamicsApr 02 2015Based on a chiral approach to nuclear matter, we calculate the quartic term in the expansion of the equation of state of isospin-asymmetric nuclear matter. The contributions to the quartic isospin asymmetry energy $A_4(k_f)$ arising from $1\pi$-exchange ... More
Resummation of in-medium ladder diagrams: s-wave effective range and p-wave interactionOct 02 2012A recent work on the resummation of fermionic in-medium ladder diagrams to all orders is extended by considering the effective range correction in the s-wave interaction and a (spin-independent) p-wave contact-interaction. A two-component recursion generates ... More
$Σ$-nuclear spin-orbit coupling from two-pion exchangeNov 14 2007Using SU(3) chiral perturbation theory we calculate the density-dependent complex-valued spin-orbit coupling strength $U_{\Sigma ls}(k_f)+ i W_{\Sigma ls}(k_f)$ of a $\Sigma$ hyperon in the nuclear medium. The leading long-range $\Sigma N$ interaction ... More
Electromagnetic corrections to the dominant two-pion exchange nucleon-nucleon potentialMay 18 2006May 19 2006We calculate at two-loop order in chiral perturbation theory the electromagnetic corrections to the dominant two-pion exchange nucleon-nucleon interaction that is generated by the isoscalar $\pi N$ contact-vertex proportional to the large low-energy constant ... More
Flow effects on jet profiles and multiplicitiesJan 24 2005We study the effects of low-$p_T$ collective flow on radiative energy loss from high-$p_T$ partons traversing the QCD medium created in high-energy nucleus-nucleus collisions. We illustrate this idea through three examples. Due to longitudinal flow, jet ... More
Review of Monte Carlo methods for particle multiplicity evaluationOct 12 2004I present a brief review of the existing models for particle multiplicity evaluation in heavy ion collisions which are at our disposal in the form of Monte Carlo simulators. Models are classified according to the physical mechanisms with which they try ... More
Parametric Ward-Takahashi identity in disordered systems and the integral identity associated with the Calogero-Sutherland modelFeb 26 1997By utilizing the symmetric property known as the Ward-Takahashi identity in disordered systems, we explore the novel symmetry relations which hold in one-dimensional systems with inverse square interaction (the Calogero-Sutherland model). The identities ... More
On Matrix Description of IIA Center of MassFeb 11 1999The correspondence between the ground states of the BFSS matrix model and the type IIA string is investigated through the 11th direction. We derive the type IIA string from 11 dimensional supermembrane wrapped around the 11th direction of periodicity ... More
The HERMES Dual-Radiator Ring Imaging Cerenkov DetectorApr 08 2001The construction and use of a dual radiator Ring Imaging Cerenkov(RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasizes measurements of semi-inclusive deep-inelastic scattering. It provides particle ... More
Oct-tree Method on GPUSep 02 2009The kd-tree is a fundamental tool in computer science. Among others, an application of the kd-tree search (oct-tree method) to fast evaluation of particle interactions and neighbor search is highly important since computational complexity of these problems ... More
Propriétés de Lefschetz automorphes pour les groupes unitaires et orthogonauxMar 03 2005Let $G$ be a connected semisimple group over ${\Bbb Q}$. Given a maximal compact subgroup and a convenient arithmetic subgroup $\Gamma\subset G({\Bbb Q})$, one constructs an arithmetic manifold $S=S(\Gamma)=\Gamma\backslash X$. If $H\subset G$ is a connected, ... More
Can there be a Fock state of the radiation field?Aug 14 2003Nov 30 2006We analyze possible hurdles in generating a Fock state of the radiation field in a micromaser cavity.
Trigger and data acquisitionOct 14 2010The lectures address some of the issues of triggering and data acquisition in large high-energy physics experiments. Emphasis is placed on hadron-collider experiments that present a particularly challenging environment for event selection and data collection. ... More
Numerical Simulation of an Electroweak OscillonJun 28 2007Oct 28 2007Numerical simulations of the bosonic sector of the $SU(2)\times U(1)$ electroweak Standard Model in 3+1 dimensions have demonstrated the existence of an oscillon -- an extremely long-lived, localized, oscillatory solution to the equations of motion -- ... More
Chiral Random Matrix Models: A Novel Intermediate Asymptotic RegimeAug 14 2002The Chiral Random Matrix Model or the Gaussian Penner Model (generalized Laguerre ensemble) is re-examined in the light of the results which have been found in double well matrix models [D97,BD99] and subtleties discovered in the single well matrix models ... More
An Eulerian Perturbation Approach to Large Scale Structures: Extending the Adhesion ApproximationNov 12 2001Nov 13 2001A description of the dynamics of a collisionless, self-gravitating fluid is developed and applied to follow the development of Large Scale Structures in the Universe. Such description takes on one of the assumptions of the Adhesion Approximation (AA) ... More
On Field Theories of LoopsNov 30 1994Aug 22 1995We apply stochastic quantization method to matrix models for the second quantization of loops in both discretized and continuum levels. The fictitious time evolution described by the Langevin equation is interpreted as the time evolution in a field theory ... More
Evolution of the Away-Side Jet Shapes in pi0-h Correlations in 200 GeV Au+Au Collisions with RHIC-PHENIXFeb 23 2007Two-particle azimuthal correlations have allowed detailed study of the modification to di-jets in the hot, dense medium created in RHIC collisions. Light can be shed by such correlations on many novel effects discovered at RHIC such as the enhanced p/pi ... More