Strange baryonic resonances and resonances coupling to strange hadrons at SIS energies
Fabbietti, L. [e12, Physik Department Technische Universität München Excellence Cluster “Origin and Structure of the Universe” (Germany)
2016-01-22
The role played by baryonic resonances in the production of final states containing strangeness for proton-proton reactions at 3.5 GeV measured by HADES is discussed by means of several very different measurements. First the associate production of Δ resonances accompanying final states with strange hadrons is presented, then the role of interferences among N{sup *} resonances, as measured by HADES for the first time, is summarised. Last but not least the role played by heavy resonances, with a mass larger than 2 GeV/c{sup 2} in the production of strange and non-strange hadrons is discussed. Experimental evidence for the presence of a Δ(2000){sup ++} are presented and hypotheses are discussed employing the contribution of similar objects to populate the excesses measured by HADES for the Ξ in A+A and p+A collisions and in the dilepton sector for A+A collisions. This extensive set of results helps to better understand the dynamic underlaying particle production in elementary reactions and sets a more solid basis for the understanding of heavy ion collisions at the same energies and even higher as planned at the FAIR facility.
Classical analogy of Fano resonances
We present an analogy of Fano resonances in quantum interference to classical resonances in the harmonic oscillator system. It has a manifestation as a coupled behaviour of two effective oscillators associated with propagating and evanescent waves. We illustrate this point by considering a classical system of two coupled oscillators and interfering electron waves in a quasi-one-dimensional narrow constriction with a quantum dot. Our approach provides a novel insight into Fano resonance physics and provides a helpful view in teaching Fano resonances
Electroproduction of Baryon Resonances and Strangeness Suppression
Santopinto, E; Tecocoatzi, H Garcia
2016-01-01
We describe the electroproduction ratios of baryon-meson states from nucleon using an extension of the quark model that takes into account the sea. As a result we provide, with no adjustable parameters, the predictions of ratios of exclusive meson-baryon final states: Lambda K , Sigma K, p pion, and n pion. These predictions are in agreement with the new Jlab experimental data showing that sea quarks play an important role in the electroproduction. We also predicted further ratios of exclusive reactions that can be measured and tested in future experiments. In particular, we suggested new experiments on deuterium and tritium. Such measurements can provide crucial test of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we computed the so called strangeness suppression factor, lambda s, that is the suppression of strange quark-antiquarks compared to nonstrange pairs, and we found that our finding with this simple extension of the qua...
Can Doubly Strange Dibaryon Resonances be Discovered at RHIC?
Paganis, S D; Ray, R L; Tang, J L; Udagawa, T; Longacre, R S
2000-01-01
The baryon-baryon continuum invariant mass spectrum generated from ultrarelativistic nucleus + nucleus collision data may reveal the existence of doubly-strange dibaryons not stable against strong decay if they lie within a few MeV of threshold. Furthermore, since the dominant component of these states is a superposition of two color-octet clusters which can be produced intermediately in a color-deconfined quark-gluon plasma (QGP), an enhanced production of dibaryon resonances could be a signal of QGP formation. A total of eight, doubly-strange dibaryon states are considered for experimental search using the STAR detector (Solenoidal Tracker at RHIC) at the new Relativistic Heavy Ion Collider (RHIC). These states may decay to Lambda-Lambda and/or proton-Cascade-minus, depending on the resonance energy. STAR's large acceptance, precision tracking and vertex reconstruction capabilities, and large data volume capacity, make it an ideal instrument to use for such a search. Detector performance and analysis sensit...
Energy dependence of K-bar N interactions and resonance pole of strange dibaryons
We study the resonance energy of the strange dibaryons using two models with the energy-independent and energy-dependent potentials for the s-wave K-bar N interaction, both of which are derived by certain reductions from the leading order term of the effective chiral Lagrangian. These potential models produce rather different off-shell behaviors of the two-body K-bar N - πΣ amplitudes in I=0 channel, i.e., the model with energy-independent (energy-dependent) potential predicts one (two) resonance pole in the Λ(1405) region, while they describe the available data equally well. We find that the energy-independent potential model predicts one resonance pole of the strange dibaryons, whereas the energy-dependent potential model predicts two resonance poles: one is the shallow quasi-bound state of the K-bar NN, and the other is the resonance of the πY N with large width. An investigation of the binding energy of the strange dibaryons will make a significant contribution to clarify resonance structure of s-wave K-bar N - πΣ around the Λ(1405) region. (author)
Role of spin-7/2 resonances in strangeness electromagnetic production
As a first step toward understanding strangeness production on nuclei, one needs to establish a sufficiently realistic description of the elementary process on a nucleon. In this purpose, a model independent approach which has already provided some interesting information on the strong points, and shortcomings, of various phenomenological formalisms as well as on the sensitivity of polarization observables to resonances in s-, u-, and t-channels is applied. (K.A.)
Nucleon Resonances in Meson Nucleon Scattering with Strangeness Production
Waluyo, A.; Bennhold, C.; Haberzettl, H.; Penner, G.; Mosel, U.; Mart, T.
2000-01-01
An effective Lagrangian model in a coupled channels framework is applied to extract nucleon resonance parameters. In the K-matrix approximation, we simultaneously analyze all the available data for the transitions from pi N to five possible meson-baryon final states, pi N, pipi N, eta N, K Lambda, and KSigma, in the energy range from pi N threshold up to W = 2 GeV. In this work, we focus our efforts on the K Sigma channel. In particular, we include a set of Delta resonances around 1900 MeV: t...
Energy dependence of barKN interactions and resonance pole of strange dibaryons
Ikeda, Yoichi; Kamano, Hiroyuki; Sato, Toru
2010-01-01
We study the resonance energy of the strange dibaryons using two models with the energy-independent and energy-dependent potentials for the s-wave barKN interaction, both of which are derived by certain reductions from the leading order term of the effective chiral Lagrangian. These potential models produce rather different off-shell behaviors of the two-body barKN - piSigma amplitudes in I=0 channel, i.e., the model with energy-independent (energy-dependent) potential predicts one (two) reso...
Decay Properties Of The Dipole Isobaric Analog Resonances
Gorelik, M L; Urin, M H
2006-01-01
A continuum-RPA-based approach is applied to describe the decay properties of isolated dipole isobaric analog resonances in nuclei having not-too-large neutron excess. Calculated for a few resonances in 90Zr the elastic E1-radiative width and partial proton widths for decay into one-hole states of 89Y are compared with available experimental data.
Observation of a narrow baryon resonance with positive strangeness formed in K+Xe collisions
Barmin, V. V.; Asratyan, A. E.; Borisov, V. S.; Curceanu, C.; Davidenko, G. V.; Dolgolenko, A. G.; Guaraldo, C.; Kubantsev, M. A.; Larin, I. F.; Matveev, V. A.; Shebanov, V. A.; Shishov, N. N.; Sokolov, L. I.; Tarasov, V. V.; Tumanov, G. K.; Verebryusov, V. S.; Diana Collaboration
2014-04-01
The charge-exchange reaction K+Xe→K0pXe' is investigated using the data of the DIANA experiment. The distribution of the pK0 effective mass shows a prominent enhancement near 1538 MeV formed by nearly 80 events above the background, whose width is consistent with being entirely due to the experimental resolution. Under the selections based on a simulation of K+Xe collisions, the statistical significance of the signal reaches 5.5σ. We interpret this observation as strong evidence for formation of a pentaquark baryon with positive strangeness, Θ+(uudds¯), in the charge-exchange reaction K+n→K0p on a bound neutron. The mass of the Θ+ baryon is measured as m (Θ+)=1538±2 MeV. Using the ratio between the numbers of resonant and nonresonant charge-exchange events in the peak region, the intrinsic width of this baryon resonance is determined as Γ (Θ+)=0.34±0.10 MeV.
Analog implementation of an integral resonant control scheme
Integral resonant control (IRC) has been introduced as a high performance controller design methodology for flexible structures with collocated actuator–sensor pairs. IRC has a simple structure and is capable of achieving significant damping, over several modes, while guaranteeing closed-loop stability of the system in the presence of unmodeled out-of-bandwidth dynamics. IRC can be an ideal controller for various industrial damping applications, if packaged in a simple easy-to-implement electronic module. This work proposes an analog implementation of the IRC scheme using a single Op-Amp circuit. The objective is to show that with simple analog realization of the modified IRC scheme, it is possible to damp a large number of vibration modes. A brief discussion about the modeling, circuit considerations, implementation and experimental results is presented in order to validate the usefulness and practicality of the proposed analog IRC implementation. (technical note)
Heavy baryonic resonances, multi strange hadrons and equilibration at SIS18 energies
Steinheimer, J; Becattini, F; Stock, R; Bleicher, M
2016-01-01
We study the details and time dependence of particle production in nuclear collisions at a fixed target beam energy of $E_{\\mathrm{lab}}= 1.76$ A GeV with the UrQMD transport model. We find that the previously proposed production mechanism for multi strange hadrons, $\\phi$ and $\\Xi$, are possible due to secondary interactions of incoming nuclei of the projectile and target with already created nuclear resonances, while the Fermi momenta of the nuclei play only a minor role. We also show how the centrality dependence of these particle multiplicities can be used to confirm the proposed mechanism, as it strongly depends on the number of participants in the reaction. Furthermore we investigate the time dependence of particle production in collisions of Ca+Ca at this beam energy, in order to understand the origins of the apparent chemical equilibration of the measured particle yields. We find that indeed the light hadron yields appear to be in equilibrium already from the very early stage of the collision while in...
Level width of giant resonances and hole analog states
Widths of giant resonances and hole analog states are evaluated from the linear response function which is proportional to the imaginary part of Green's function. The Hartree Fock hamiltonian obtained by using the Skyrme interactions is diagonalized with harmonic oscillator basis. The resulting single particle states are all bound, and the continuum wave functions are constructed to be orthogonal to the bound states. Using these bases the energy matrix is calculated, where the self-energy is added to the particle or hole energy. The imaginary part of the self-energy consists of two parts, one corresponds to decay into more complicated states and other corresponds to decay into the continuum. The matrix is inverted and Green's function is obtained. The calculations are carried out for monopole states in 40Ca and hole analog states in 207Pb. The latter results are compared with the experimental data. (author)
David, J.C.
1994-09-01
The purpose of this thesis is to study the kaon photoproduction off a proton ({gamma}p {yields} K{sup +}{Lambda},{gamma}p {yields} K{sup +}{Sigma}{sup 0}, {gamma}p {yields} K{sup 0}{Sigma}{sup +}), with a photon energy between 0.9 and 2.1 GeV. We use an isobaric model where the amplitudes are computed with Feynman diagrams. The insertion of nucleonic resonances with spin 3/2 and 5/2 is necessary to improve the existing models beyond 1.5 GeV. This step is also necessary to extend the elementary process of photoproduction to electroproduction where the data have been taken with photon energies above 2.0 GeV. The parameters of our models are the coupling constants which appear at each Feynman diagram vertex. They are determined by fitting our models to the experimental data (cross sections, polarization asymmetries). Before performing the minimization we drew some informations about coupling constants from mesonic and electromagnetic decays, and from SU(3) and SU(6) symmetries. In conclusion, the models developed here reproduce the experimental data (E{sub {gamma}} {<=} 2.0 GeV) and the two main coupling constants are in good agreement with broken SU(3)-symmetry predictions. (author). 47 refs.
Strange matter at finite temperatures
The properties of strange quark matter at finite temperatures and in equilibrium with respect to weak interaction are explored on the basis of the MIT bag model picture of QCD. Furthermore, to determine the stability of strange quark matter analogous investigations are also performed for nuclear matter within Walecka's model field theory. It is found that strange quark matter can be stable at zero external pressure only for temperatures below 20 MeV. (orig.)
Production rates of strange vector mesons at the Z{sup 0} resonance
Dima, M.O.
1997-05-01
This dissertation presents a study of strange vector meson production, {open_quotes}leading particle{close_quotes} effect and a first direct measurement of the strangeness suppression parameter in hadronic decays of the neutral electroweak boson, Z{sup 0}. The measurements were performed in e{sup +}e{sup -} collisions at the Stanford Linear Accelerator Center (SLAC) with the SLC Large Detector (SLD) experiment. A new generation particle ID system, the SLD Cerenkov Ring Imaging Detector (CRID) is used to discriminate kaons from pions, enabling the reconstruction of the vector mesons over a wide momentum range. The inclusive production rates of {phi} and K*{sup 0} and the differential rates versus momentum were measured and are compared with those of other experiments and theoretical predictions. The high longitudinal polarisation of the SLC electron beam is used in conjunction with the electroweak quark production asymmetries to separate quark jets from antiquark jets. K*{sup 0} production is studied separately in these samples, and the results show evidence for the {open_quotes}leading particle{close_quotes} effect. The difference between K*{sup 0} production rates at high momentum in quark and antiquark jets yields a first direct measurement of strangeness suppression in jet fragmentation.
Production rates of strange vector mesons at the Z0 resonance
This dissertation presents a study of strange vector meson production, open-quotes leading particleclose quotes effect and a first direct measurement of the strangeness suppression parameter in hadronic decays of the neutral electroweak boson, Z0. The measurements were performed in e+e- collisions at the Stanford Linear Accelerator Center (SLAC) with the SLC Large Detector (SLD) experiment. A new generation particle ID system, the SLD Cerenkov Ring Imaging Detector (CRID) is used to discriminate kaons from pions, enabling the reconstruction of the vector mesons over a wide momentum range. The inclusive production rates of φ and K*0 and the differential rates versus momentum were measured and are compared with those of other experiments and theoretical predictions. The high longitudinal polarisation of the SLC electron beam is used in conjunction with the electroweak quark production asymmetries to separate quark jets from antiquark jets. K*0 production is studied separately in these samples, and the results show evidence for the open-quotes leading particleclose quotes effect. The difference between K*0 production rates at high momentum in quark and antiquark jets yields a first direct measurement of strangeness suppression in jet fragmentation
Study of strange mesonic resonance production in K-p interactions at 14.3GeV/c
The production of strange S=-1 mesonic resonances in K-p interactions at 14.3GeV/c was studied. The experimental data come from a 1.3 million exposure of the CERN 2 meters hydrogen bubble chamber. The anti-Kπ system from the anti-KπN final state is analysed with emphasis on the comparison between the production mechanisms of the reactions K-p→anti-K*(890)N and K-p→anti-K*(1420)N. Evidence is given for the production of a new K*, the K*(1780) of spin-parity 3- and some of its important parameters are determined. The Triple Regge model predictions are verified for reactions with inclusive K* production: K-p→K*-(890)+X+ and K-p→anti-K*0(890)+X0
Barmin, V. V.; Asratyan, A. E.; Borisov, V. S.; Curceanu, C.; Davidenko, G. V.; Dolgolenko, A. G.; Guaraldo, C.; Kubantsev, M. A.; Larin, I. F.; Matveev, V. A.; Shebanov, V. A.; Shishov, N. N.; Sokolov, L. I.; Tumanov, G. K.
2007-01-01
We have continued our investigation of the charge-exchange reaction K +Xe → K 0 pXe’ in the bubble chamber DIANA. In agreement with our previous results based on part of the present statistics, formation of a narrow pK 0 resonance with mass of 1537 ± 2 MeV/c 2 is observed in the elementary transition K + n → K 0 p on a neutron bound in the xenon nucleus. The visible width of the peak is consistent with being entirely due to instrumental resolution and allows one to place an upper limit on its intrinsic width: Γ < 9 MeV/c 2. A more precise estimate of the resonance intrinsic width, Γ = 0.36 ± 0.11 MeV/c 2, is obtained from the ratio between the numbers of resonant and nonresonant charge-exchange events. The signal is observed in a restricted interval of incident K + momentum that is consistent with smearing of a narrow pK 0 resonance by Fermi motion of the target neutron. The statistical significance of the signal is some 7.3, 5.3, and 4.3 standard deviations for the estimators S/sqrt B ,S/sqrt {S + B} and S/sqrt {S + 2B} , respectively. This observation confirms and reinforces our earlier results, and offers strong evidence for formation of a pentaquark baryon with positive strangeness in the charge-exchange reaction K + n → K 0 p on a bound neutron.
Observation of a narrow baryon resonance with positive strangeness formed in $K^+$Xe collisions
Barmin, V V; Borisov, V S; Curceanu, C; Davidenko, G V; Dolgolenko, A G; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tarasov, V V; Tumanov, G K; Verebryusov, V S
2013-01-01
The data on the charge-exchange reaction K^+ Xe --> K^0 p Xe', obtained with the Xenon bubble chamber DIANA, are reanalyzed using increased statistics and modified selections. The distribution of the pK^0 effective mass shows a prominent enhancement near 1538 MeV whose width is consistent with being entirely due to experimental resolution. A corresponding enhancement at m(pK^0) \\simeq 1538 MeV and p(K^+)\\simeq 490 MeV is observed in the m(pK^0)--p(K^+) scatter plot. Using a simulation of K^+ Xe collisions that includes the development of the intranuclear cascade, we show that the observed enhancement is not a spurious structure created by the selections. The statistical significance of the signal, estimated as \\sqrt{2\\Delta\\lnL}, reaches 6.3 standard deviations. We interpret this observation as strong evidence for formation of a pentaquark baryon with positive strangeness, \\Theta^+(uudd\\bar{s}), in the charge-exchange reaction K^+ p --> K^0 n on a bound neutron. The mass of the \\Theta^+ baryon is measured as ...
Study of $^{13}$Be through isobaric analog resonances in the Maya active target
Riisager, K; Orr, N A; Jonson, B N G; Raabe, R; Fynbo, H O U; Nilsson, T
We propose to perform an experiment with a $^{12}$Be beam and the Maya active target. We intend to study the ground state of $^{13}$Be through the population of its isobaric analog resonance in $^{13}$B. The resonance will be identified detecting its proton- and neutron-decay channels.
Study of leading strange meson resonances and spin-orbit splittings in K-p → K-π+n at 11 GeV/c
The results from a high-statistics study of Kπ elastic scattering in the reaction K-p → K-π+n are presented. The data for this analysis are taken from an 11-GeV/c K-p experiment performed on the Large Aperture Solenoidal Spectrometer (LASS) facility at the Stanford Linear Accelerator Center (SLAC). By selecting the very forward produced K-π+ events, a sample consisting of data for the Kπ → Kπ elastic scattering reaction was extracted. The angular distribution for this meson-meson scattering is studied by use of both a spherical harmonic moments analysis and a partial-wave analysis (PWA). The previously established leading natural spin-parity strange meson resonances (the J/sup P/ = 1- K*(895), the 2+ K*(1430), and the 3- K*(1780)) are observed in the results from both the moments analysis and the PWA. In addition, evidence for a new spin 4- K* resonance with a mass of 2080 MeV and a width of about 225 MeV is presented. The results from the PWA confirm the existence of a 0+ kappa (1490) and propose the existence of a second scalar meson resonance, the 0+ kappa' (1900). Structure in the P-wave amplitude indicates resonance behavior in the mass region near 1700 MeV. In two of the four ambiguous solutions for the mass region above 1800 MeV, there is strong evidence for another P-wave resonant structure near 2100 MeV. The observed strange meson resonances are found to have a natural interpretation in terms of states predicted by the quark model. In particular, the mass splittings of the leading trajectory natural spin-parity strange meson states and the mass splittings between the spin-orbit triplet states are discussed. 59 figures, 17 tables
Honma, A.K.
1980-11-01
The results from a high-statistics study of K..pi.. elastic scattering in the reaction K/sup -/p ..-->.. K/sup -/..pi../sup +/n are presented. The data for this analysis are taken from an 11-GeV/c K/sup -/p experiment performed on the Large Aperture Solenoidal Spectrometer (LASS) facility at the Stanford Linear Accelerator Center (SLAC). By selecting the very forward produced K/sup -/..pi../sup +/ events, a sample consisting of data for the K..pi.. ..-->.. K..pi.. elastic scattering reaction was extracted. The angular distribution for this meson-meson scattering is studied by use of both a spherical harmonic moments analysis and a partial-wave analysis (PWA). The previously established leading natural spin-parity strange meson resonances (the J/sup P/ = 1/sup -/ K*(895), the 2/sup +/ K*(1430), and the 3/sup -/ K*(1780)) are observed in the results from both the moments analysis and the PWA. In addition, evidence for a new spin 4/sup -/ K* resonance with a mass of 2080 MeV and a width of about 225 MeV is presented. The results from the PWA confirm the existence of a 0/sup +/ kappa (1490) and propose the existence of a second scalar meson resonance, the 0/sup +/ kappa' (1900). Structure in the P-wave amplitude indicates resonance behavior in the mass region near 1700 MeV. In two of the four ambiguous solutions for the mass region above 1800 MeV, there is strong evidence for another P-wave resonant structure near 2100 MeV. The observed strange meson resonances are found to have a natural interpretation in terms of states predicted by the quark model. In particular, the mass splittings of the leading trajectory natural spin-parity strange meson states and the mass splittings between the spin-orbit triplet states are discussed. 59 figures, 17 tables.
Formation of a narrow baryon resonance with positive strangeness in K^+ collisions with Xe nuclei
Barmin, V V; Borisov, V S; Curceanu, C; Davidenko, G V; Dolgolenko, A G; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tumanov, G K; Verebryusov, V S
2009-01-01
The data on the charge-exchange reaction K^+Xe --> K^0 p Xe, obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK^0 resonance with mass near 1538 MeV is confirmed and reinforced. The statistical significance of the signal reaches some 8\\sigma (6\\sigma) when estimated as S/\\sqrt{B} (S/\\sqrt{B+S}). The mass and intrinsic width of the \\Theta^+ baryon are measured as m = (1538+-2) MeV and \\Gamma = (0.39+-0.10) MeV.
Formation of a narrow baryon resonance with positive strangeness in K+ collisions with Xe nuclei
The data on the charge-exchange reaction K+Xe → K0pXe', obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK0 resonance with mass near 1538 MeV is confirmed. The statistical significance of the signal reaches some 8σ (6σ) standard deviations when estimated as S/√B (S/√B + S. The mass and intrinsic width of the Θ+ baryon are measured as m = 1538 ± 2 MeV and Γ = 0.39 ± 0.10 MeV.
Formation of a narrow baryon resonance with positive strangeness in K + collisions with Xe nuclei
Barmin, V. V.; Asratyan, A. E.; Borisov, V. S.; Curceanu, C.; Davidenko, G. V.; Dolgolenko, A. G.; Guaraldo, C.; Kubantsev, M. A.; Larin, I. F.; Matveev, V. A.; Shebanov, V. A.; Shishov, N. N.; Sokolov, L. I.; Tumanov, G. K.; Verebryusov, V. S.
2010-07-01
The data on the charge-exchange reaction K +Xe → K 0 pXe', obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK 0 resonance with mass near 1538 MeV is confirmed. The statistical significance of the signal reaches some 8 (6) standard deviations when estimated as {S {sqrt B ( {{S {/ {sqrt {B + S} }}} )}} . The mass and intrinsic width of the Θ+ baryon are measured as m = 1538 ± 2 MeV and Γ = 0.39 ± 0.10 MeV.
Bazavov, A; DeTar, C E; Ding, H -T; Gottlieb, Steven; Gupta, Rajan; Hegde, P; Heller, Urs; Karsch, F; Laermann, E; Levkova, L; Mukherjee, Swagato; Petreczky, P; Schmidt, Christian; Soltz, R A; Soeldner, W; Sugar, R; Vranas, Pavlos M
2012-01-01
We calculate the quadratic fluctuations of net baryon number, electric charge and strangeness as well as correlations among these conserved charges in (2+1)-flavor lattice QCD at zero chemical potential. Results in the continuum limit are obtained using calculations with tree level improved gauge and the highly improved staggered quark (HISQ) actions with almost physical light and strange quark masses at three different values of the lattice cut-off. We compare our results with the hadron resonance gas (HRG) model calculations and find agreement with HRG model results only for temperatures T < 150 MeV. We observe significant deviations in the temperature range 160 MeV < T < 170 MeV and qualitative differences in the behavior of the three conserved charge sectors. At $T \\simeq 160 MeV$ quadratic net baryon number fluctuations in QCD agree with HRG model calculations while, the net electric charge fluctuations in QCD are about 10% smaller and net strangeness fluctuations are about 20% larger. These fin...
Interpretation of strange hadron production at LHC
We extend the SHM analysis of hadron production results showing here consistency with the increased experimental data set, stability of the fit with regard to inclusion of finite resonance widths and 2-star hyperon resonances. We present new results on strangeness yield as a function of centrality and present their interpretation in terms of QGP inspired model of strangeness abundance in the hadronizing fireball
Exotic mesons with JPC=1-+, strange and non-strange
We analyse the QCD sum rules for the exotic quark-antiquark-gluon states called ''glukonium'' or ''hermaphrodite'' mesons. We predict a non-strange resonance of this type at ∝1.5 GeV, a strange one at ∝1.6 GeV and a strange-antistrange one at ∝1.75 GeV. It should be noted that the above values of masses depend crucially on the vacuum expectation value of the gluon field operator 3fabc.GaμνGbνλGcλμ>. (orig.)
A test of the theory of resonant scattering between analog nuclei
It has been suggested that strong resonances might be found in scattering between analog nuclei at energies near the Coulomb barrier. The authors have begun a study of such scattering for 7Be on 7Li using a 7Be beam produced with the OSU-LLNL radioactive ion beam facility. The resulting excitation function can be used to limit a combination of the strength and the width of any possible resonances
David Robert Cole
2014-08-01
Full Text Available This paper contends that the power of Deleuze & Guattari’s (1988 notion of assemblage as theorised in 1000 Plateaus can be normalised and reductive with reference to its application to any social-cultural context where an open system of dynamic and fluid elements are located. Rather than determining the assemblage in this way, this paper argues for an alternative conception of ‘strange assemblage’ that must be deliberately and consciously created through rigorous and focused intellectual, creative and philosophical work around what makes assemblages singular. The paper will proceed with examples of ‘strange assemblage’ taken from a film by Peter Greenaway (A Zed and 2 Noughts; the film ‘Performance’; educational research with Sudanese families in Australia; the book, Bomb Culture by Jeff Nuttall (1970; and the band Hawkwind. Fittingly, these elements are themselves chosen to demonstrate the concept of ‘strange assemblage’, and how it can be presented. How exactly the elements of a ‘strange assemblage’ come together and work in the world is unknown until they are specifically elaborated and created ‘in the moment’. Such spontaneous methodology reminds us of the 1960s ‘Happenings’, the Situationist International and Dada/Surrealism. The difference that will be opened up by this paper is that all elements of this ‘strange assemblage’ cohere in terms of a rendering of ‘the unacceptable.'
Lian-Rong, Dai; Zong-Ye, Zhang; You-Wen, Yu
2006-01-01
The structure of $(\\Omega\\Omega)_{0^+}$ dibaryon with strangeness $s=-6$ is studied in the extended chiral SU(3) quark model, in which vector meson exchange dominates the short range interaction. The resonating group method (RGM) is adopted, in which the $\\Omega\\Omega$ and $CC$ (hidden color) channels are involved. The color screening effect and the effects of mixing of scalar mesons on $(\\Omega\\Omega)_{0^+}$ are also investigated.
Prospects for strangeness measurement in ALICE
The study of strangeness production at LHC will bring significant information on the bulk chemical properties, its dynamics, and the hadronization mechanisms involved at these energies. The ALICE experiment will measure strange particles from topology (secondary vertices) and from resonance decays over a wide range in transverse momentum and shed light on this new QCD regime. These motivations will be presented as well as the identification performance of ALICE for strange hadrons.
Demonstration of a 3-bit optical digital-to-analog converter based on silicon microring resonators.
Yang, Lin; Ding, Jianfeng; Chen, Qiaoshan; Zhou, Ping; Zhang, Fanfan; Zhang, Lei
2014-10-01
We propose an N-bit optical digital-to-analog converter based on silicon microring resonators (MRRs), which can transform an N-bit electrical digital signal to an optical analog signal. A 3-bit optical digital-to-analog convertor is fabricated as proof of concept through a CMOS-compatible process on a silicon-on-insulator platform. The silicon MRRs are modulated through the electric-field-induced carrier injection in forward biased PN junctions embedded in the ring waveguides. The electro-optical 3-dB bandwidths of the silicon MRRs are approximately 800 MHz. The device works well at a speed of 500 MSample/s under driving voltage swings of 0.75 V. PMID:25360972
Chemical Freeze-out of Strange Particles and Possible Root of Strangeness Suppression
Bugaev, K A; Cleymans, J; Ivanytskyi, A I; Mishustin, I N; Nikonov, E G; Sagun, V V
2013-01-01
Two approaches to treat the chemical freeze-out of strange particles in hadron resonance gas model are analyzed. The first one employs their non-equillibration via the usual \\gamma_s factor and such a model describes the hadron multiplicities measured in nucleus-nucleus collisions at AGS, SPS and RHIC energies with \\chi^2/dof = 1.15. Surprisingly, at low energies we find not the strangeness suppression, but its enhancement. Also we suggest an alternative approach to treat the strange particle freeze-out separately, but with the full chemical equilibration. This approach is based on the conservation laws which allow us to connect the freeze-outs of strange and non-strange hadrons. Within the suggested approach the same set of hadron multiplicities can be described better than within the conventional approach with \\chi^2/dof = 1.06. Remarkably, the fully equilibrated approach describes the strange hyperons and antihyperons much better than the conventional one.
Search for non-strange dibaryons
Arun K Jain
2006-05-01
Inspite of tremendous interest there has been sporadic searches for dibaryon resonances in the past few decades. The main hurdle one faces in this search is their identification, their signature and practically no guide to their location. With the identification of the pentaquark-+ resonance one is encouraged to look for the discovery of strange dibaryons also. However where and how to look for non-strange dibaryons is not clear. The transition from a bipolar to a unipolar non-strange dibaryon may possibly be seen in the (, 2) reactions on heavy nuclei. The change of the finite size of the $p-p$ interaction vertex can be identified as a sudden change in the extracted DWIA spectroscopic factor. The DWIA anomalies are to be searched for in the existing (, 2) reaction data for the identification of non-strange dibaryons.
Optical Analog-to-digital Conversion Scheme Based on Tunable Fabry-Perot Resonator
LI Zheng
2007-01-01
Proposed is an interference type of optical analog-to-digital conversion(ADC). The refractive index of Fabry-Perot cavity changes with different voltages. The Fabry-Perot resonator converts electronic intensity into light wavelength through selecting lights of different wavelengthes. The parameters of the scheme are acquired with the transmission matrix of optical element and the time of steady-state light field. The maximum sampling speedes of 4-bit, 6-bit, 7-bit, 8-bit and 9-bit(ADC) are 1.695×1010 count/s, 4.33×109 count/s, 2.38×109 count/s, 1.24×109 count/s and 5.9×108 count/s, respectively.
Anti-analog giant dipole resonances and the neutron skin of nuclei
We examine a method to determine the neutron-skin thickness of nuclei using data on the charge-exchange anti-analog giant dipole resonance (AGDR). Calculations performed using the relativistic proton–neutron quasiparticle random-phase approximation (pn-RQRPA) reproduce the isotopic trend of the excitation energies of the AGDR, as well as that of the spin-flip giant dipole resonances (IVSGDR), in comparison to available data for the even–even isotopes 112–124Sn. It is shown that the excitation energies of the AGDR, obtained using a set of density-dependent effective interactions which span a range of the symmetry energy at saturation density, supplemented with the experimental values, provide a stringent constraint on value of the neutron-skin thickness. For 124Sn, in particular, we determine the value ΔRpn=0.21±0.05 fm. The result of the present study shows that a measurement of the excitation energy of the AGDR in (p,n) reactions using rare-isotope beams in inverse kinematics, provides a valuable method for the determination of neutron-skin thickness in exotic nuclei
Siebenson, Johannes Stephan
2013-04-18
The present work investigates the vacuum properties of the hyperon resonances {Sigma}(1385){sup +} and {Lambda}(1405). For this purpose, p+p reactions at 3.5 GeV kinetic beam energy were analyzed. By using simulations and a special background method, the Breit-Wigner mass and width of the {Sigma}(1385){sup +} could be determined. Furthermore, its production dynamics were studied in different angular distributions. In this context indications were found that the {Sigma}(1385){sup +} partially stems from the decay of a heavy {Delta}-resonance. The investigation of the {Lambda}(1405) was based on similar analysis methods. After acceptance and efficiency corrections, the spectral shape of the {Lambda}(1405) could be extracted. Here a mass shift of this particle to masses below 1400 MeV/c{sup 2} was found. This might reveal important information about the two pole structure of the {Lambda}(1405) and its influence on the low energy anti KN interaction.
Barmin, V V; Borisov, V S; Curceanu, C; Davidenko, G V; Dolgolenko, A G; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tumanov, G K
2007-01-01
A narrow pKo resonance with mass of 1537 +- 2 MeV/c^2 has been observed in the charge-exchange reaction K+n->KoP on a neutron bound in the Xenon nucleus. Visible width of the peak is consistent with being entirely due to instrumental smearing and allows to place an upper limit on intrinsic width Gamma KoP on a bound neutron.
Tolos, Laura; Khemchandani, Kanchan; Martinez-Torres, Alberto; Bratkovskaya, Elena; Aichelin, Joerg; Nielsen, Marina; Navarra, Fernando S
2015-01-01
We study the properties of strange mesons in vacuum and in the hot nuclear medium within unitarized coupled-channel effective theories. We determine transition probabilities, cross sections and scattering lengths for strange mesons. These scattering observables are of fundamental importance for understanding the dynamics of strangeness production and propagation in heavy-ion collisions.
We present a new approach for the measurement of resonance excitation functions of neutron-rich nuclei using Doppler shift information. Preliminary data from the first application of the method is presented in the spectroscopy studies of 7He isobaric analog states in 7Li. (orig.)
Electromagnetic production of associated strangeness
A formalism, based on an isobaric approach using Feynman diagram techniques, which includes the nucleonic (spin ≤ 5/2), hyperonic (spin 1/2) and kaonic resonances, is developed. Using this formalism, a thorough investigation of electromagnetic strangeness processes is performed. A reaction mechanism, describing well enough the data, is found to include a reasonable number of baryonic resonances among a very large number of potential candidates. Predictions for the upcoming photoproduction polarization and electroproduction observables are presented, and their sensitivity to the phenomenological models ingredients are emphasized. (K.A.)
Weak Strangeness and Eta Production
Alam, M Rafi; Alvarez-Ruso, Luis; Simo, I Ruiz; Vacas, M J Vicente; Singh, S K
2013-01-01
We have studied strange particle production off nucleons through $\\Delta S =0 $ and $|\\Delta S| = 1$ channels, and specifically single kaon/antikaon, eta, associated particle production for neutrino/antineutrino induced processes as well as antineutrino induced single hyperon production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangians. The basic parameters of the model are $f_\\pi$, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included $\\Sigma^*(1385)$ resonance and for eta production $S_{11}(1535)$ and $S_{11}(1650)$ resonances are included.
Superbursts from Strange Stars
Page, D; Page, Dany; Cumming, Andrew
2005-01-01
Recent models of carbon ignition on accreting neutron stars predict superburst ignition depths that are an order of magnitude larger than observed. We explore a possible solution to this problem, that the compact stars in low mass X-ray binaries that have shown superbursts are in fact strange stars with a crust of normal matter. We calculate the properties of superbursts on strange stars, and the resulting constraints on the properties of strange quark matter. We show that the observed ignition conditions exclude fast neutrino emission in the quark core, for example by the direct Urca process, which implies that strange quark matter at stellar densities should be in a color superconducting state. For slow neutrino emission in the quark matter core, we find that reproducing superburst properties requires a definite relation between three poorly constrained properties of strange quark matter: its thermal conductivity, its slow neutrino emissivity and the energy released by converting a nucleon into strange quar...
Olinto, A.V. [Chicago Univ., IL (United States). Dept. of Astronomy and Astrophysics]|[Fermi National Accelerator Lab., Batavia, IL (United States)
1991-12-01
Strange matter may be the ground state of matter. We review the phenomenology and astrophysical implications of strange matter, and discuss the possible ways for testing the strange matter hypothesis.
We investigate the properties of multi-strange baryonic systems, comparing conventional many -- Λ hypernuclei, where the strange quarks are localized in individual hyperons, to ''strangelets'' or chunks of strange matter, which involves delocalized quarks which roam in a single large bag. Mass formulae and strong/weak decay modes for such objects are discussed, as well as the prospects for producing multi-strange systems in relativistic heavy ion collisions. For production, we consider two extremes, one based on the coalescence model and another which assumes the formation of quark-gluon-plasma. We mention the experimental searches which are underway or planned, using heavy ion beams
Strange and charm mesons at FAIR
Tolos, L; Gamermann, D; Garcia-Recio, C; Molina, R; Nieves, J; Oset, E; Ramos, A
2009-01-01
We study the properties of strange and charm mesons in hot and dense matter within a self-consistent coupled-channel approach for the experimental conditions of density and temperature expected for the CBM experiment at FAIR/GSI. The in-medium solution at finite temperature accounts for Pauli blocking effects, mean-field binding of all the baryons involved, and meson self-energies. We analyze the behaviour in this hot and dense environment of dynamically-generated baryonic resonances together with the evolution with density and temperature of the strange and open-charm meson spectral functions. We test the spectral functions for strange mesons using energy-weighted sum rules and finally discuss the implications of the properties of charm mesons on the D_{s0}(2317) and the predicted X(3700) scalar resonances.
Strangeness in nuclear physics
Gal, A; Millener, D J
2016-01-01
Extensions of nuclear physics to the strange sector are reviewed, covering data and models of Lambda and other hypernuclei, multi-strange matter, and anti-kaon bound states and condensation. Past achievements are highlighted, present unresolved problems discussed, and future directions outlined.
Bottom-strange mesons in hyperonic matter
Pathak, Divakar
2014-01-01
The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of their medium mass on baryonic density and strangeness content of the medium. Certain aspects of these in-medium interactions are similar to those observed for the strange-charmed mesons in a preceding investigation, such as the lifting of mass-degeneracy of $B_S^0$ and ${\\bar B}_S^0$ mesons in hyperonic matter, while the same is respected in vacuum as well as in nuclear matter. In general, however, there is a remarkable distinction between the two species, even though the formalism predicts a completely analogous in-medium...
A Küçükbursa; D I Salamov; T Babacan; H A Aygör
2004-11-01
Within the quasi-particle random phase approximation (QRPA), the method of the self-consistent determination of the isovector effective interaction which restores a broken isotopic symmetry for the nuclear part of the Hamiltonian is given. The effect of the pairing correlations between nucleons on the following quantities were investigated for the = 208 nuclei: energies of the isobar analog 0+ states, the isospin admixtures in the ground state of the even–even nuclei, and the differential cross-section for the 208Pb(3He,)208Bi reaction at E(3He) = 450 MeV. Both couplings of the excitation branches with z = 0 ± 1, and the analog state with isovector monopole resonance (IVMR) in the quasi-particle representation were taken into account in our calculations. As a result of these calculations, it was seen that the pairing correlations between nucleons have no considerable effect on the = 23 isospin admixture in the ground state of the 208Pb nucleus, and they cause partially an increase in the isospin impurity of the isobar analog resonance (IAR). It was also established that these correlations have changed the isospin structure of the IAR states, and shifted the energies of the IVMR states to the higher values.
Neutron-skin thickness of 208Pb from the energy of the anti-analog giant dipole resonance
Krasznahorkay, A; Vretenar, D; Harakeh, M N
2013-01-01
The energy of the charge-exchange Anti-analog Giant Dipole Resonance (AGDR) has been calculated for the 208Pb isotope using the state-of-the-art fully self-consistent relativistic proton-neutron quasiparticle random-phase approximation based on the Relativistic Hartree-Bogoliubov model. It is shown that the AGDR centroid energy is very sensitively related to the corresponding neutron-skin thickness. The neutron-skin thickness of 208Pb has been determined very precisely by comparing the theoretical results with the available experimental data on E(AGDR). The result DR(pn)= 0.161(42) agrees nicely with the previous experimental results.
Minicomputer Mera-400 based analog signal data acquisition system is described. The peripherical controlers of the computer and the operating system SOM-3 are used. The analog signal is first digitized and stored in 1024 words of 8 bit buffer memory of the transient recorder and then transferred into the minicomputer memory for averaging. 1 k words of the computer memory can be shown on a CRT of a simple graphic display or registered on a X-Y recorder. A detail description of the hardware and of the software written in the assembler is also presented. (author)
Recurrences of strange attractors
E J Ngamga; A Nandi; R Ramaswamy; M C Romano; M Thiel; J Kurths
2008-06-01
The transitions from or to strange nonchaotic attractors are investigated by recurrence plot-based methods. The techniques used here take into account the recurrence times and the fact that trajectories on strange nonchaotic attractors (SNAs) synchronize. The performance of these techniques is shown for the Heagy-Hammel transition to SNAs and for the fractalization transition to SNAs for which other usual nonlinear analysis tools are not successful.
Chemical equilibration of strangeness
Sollfrank, Josef
1997-01-01
Thermal models are very useful in the understanding of particle production in general and especially in the case of strangeness. We summarize the assumptions which go into a thermal model calculation and which differ in the application of various groups. We compare the different results to each other. Using our own calculation we discuss the validity of the thermal model and the amount of strangeness equilibration at CERN-SPS energies. Finally the implications of the thermal analysis on the r...
[Through strangeness to oneself].
Sorgedrager, D B
1993-11-01
"Being strange" as opposed to "being oneself" is part of the thinking in all cultures. Belonging to a given culture is actually defined by ones identity and by "being oneself". Both concepts--"being oneself" or "being strange"--are rational and related constructs. Whatever they are confronted with, for most human beings it is self-evident to differentiate between subject and object, between "being oneself" or "being strange". This explains why thinking often occurs in opposites or polarities, as an either/or. All "being strange" has its origins in one's own self. "Being strange" becomes most obvious when persons, gestalt or cultures strongly deviate from one's own familiar situation. It is part of man's disposition to be cautious, suspicious of and at distance from everything considered strange and different. That explains his xenophobia feelings and actions. Behind this attitude we can always discover one's wish to preserve the familiar beliefs--combined with an uneasiness to give up one's thinking and behaviour that is proven and routine. It is only by reflecting on our own culture and our own inheritance that we have the possibility to come to terms with our own ethnic identity and foreign behavioral patterns. If we do not try to understand other cultures while keeping our own cultural identity, tensions and violent conflicts will inevitably result. PMID:8278564
Excitation functions have been measured for elastic scattering of polarized protons from 206Pb and 208Pb, and for inelastic scattering to collective states in 206Pb (2+, 0.8033 MeV; 3-, 2.647 MeV) and 208Pb (3-, 2.6145 MeV). Both differential cross sections and analyzing powers were measured at theta/sub lab/ = 1200, 1350, 1500, and 1650, for E/sub p/ = 14.25 to 18 MeV. Fits to the excitation-function data were obtained using scattering amplitudes consisting of sums of resonant and non-resonant parts. The resonances are the isobaric analogs (IARs) of 7 low-lying states in 209Pb and 35 in 207Pb. The fits to the elastic-scattering data are excellent; for the inelastic scattering the fit is very good for the 2+ state but only fair for the 3- states. For each IAR, the energy, the total width, and the partial width and mixing phase in each channel were obtained. Also, new spin assignments were made for a number of parent states in 207Pb. The theory of Bund and Blair was used to find the spectroscopic amplitudes, which provide information on the wave functions for the parent states in 207Pb and 209Pb and for the 3- states in 206Pb and 208Pb. These spectroscopic amplitudes were then checked for internal consistency and compared with the results of other experiments and with theoretical predictions
Strange Pentaquark Hadrons in Statistical Hadronization
Letessier, J.; Torrieri, G.; Steinke, S.; Rafelski, J.
2003-01-01
We study, within the statistical hadronization model, the influence of narrow strangeness carrying baryon resonances (pentaquarks) on the understanding of particle production in relativistic heavy ion collisions. There is a great variation of expected yields as function of heavy ion collision energy due to rapidly evolving chemical conditions at particle chemical freeze-out. At relatively low collision energies, these new states lead to improvement of statistical hadronization fits.
申影; 何阅; 姜玉梅; 何大韧
2004-01-01
This article reports an observation on a fat strange repeller, which appears after a characteristic crisis observed in a kicked rotor subjected to a piecewise continuous force field. The discontinuity border in the definition range of the two-dimensional mapping, which describes the system, oscillates as the discrete time develops. At a threshold of a control parameter a fat chaotic attractor suddenly transfers to a fat transient set. The strange repeller, which appears after the crisis, is also a fat fractal. This is the reason why super-transience happens
Cao, L G; Colo', G; Sagawa, H
2015-01-01
We investigate the impact of the neutron-skin thickness Delta(R) on the energy difference between the anti-analog giant dipole resonance (AGDR), E(AGDR), and the isobaric analog state (IAS), E(IAS), in a heavy nucleus such as 208Pb. For guidance, we first develop a simple and analytic, yet physical, approach based on the Droplet Model that linearly connects the energy difference E(AGDR)-E(IAS) with Delta(R). To test this correlation on more fundamental grounds, we employ a family of systematically varied Skyrme energy density functionals where variations on the value of the symmetry energy at saturation density J are explored. The calculations have been performed within the fully self consistent Hartree-Fock (HF) plus charge-exchange random phase approximation (RPA) framework. We confirm the linear correlation within our microscopic apporach and, by comparing our results with available experimental data in 208Pb, we find that our analysis is consistent with Delta(R) = 0.204 \\pm 0.009 fm, J = 31.4 \\pm 0.5 MeV ...
Exact strangeness conservation and particle production
Cleymans, J.; Redlich, K.; Suhonen, E.
The production of strange particles is studied in terms of a statistical formalism requiring strangeness to be exactly conserved while baryon number is treated grand canonically using a chemical potential. The gas is considered to be in thermal and chemical equilibrium and to have zero overall strangeness. All particles and resonances having masses up to approximately 2 GeV and strangeness up to plus or minus 3 are included. General formulas for different particle multiplicities in terms of infinite series of modified Bessel functions are derived. In contrast to the integral representation of particle numbers in the canonical ensemble, results can be easily handled numerically since the series converge very rapidly. As an illustration, the above formalism is applied to the description of particle production in proton-proton, proton-nucleus and nucleus-nucleus collisions. In particular the K/pi ratio shows a strong dependence on the interaction volume on the system while, in contrast, the antiLambda/Lambda ratio is almost independent of the volume. These results are in qualitative agreement with experimental data.
Peláez, J R
2016-01-01
We review how the Regge trajectory of an elastic resonance can be obtained just from its pole position and coupling, using a dispersive formalism. This allows us to deal correctly with the finite widths of resonances in Regge trajectories. In this way we can calculate the Regge trajectories for the $K^*(892)$, $K_1(1400)$ and $K^*_0(1430)$, obtaining ordinary linear Regge trajectories, expected for $q \\bar q$ resonances. In contrast, for the $K^*_0(800)$ meson, the resulting Regge trajectory is non-linear and with much smaller slope, strongly supporting its non-ordinary nature.
Strangeness Production in AA and pp Collisions
Satz, P Castorina ad H
2016-01-01
Boost-invariant hadron production in high energy collisions occurs in causally disconnected regions of finite space-time size. As a result, globally conserved quantum numbers (charge, strangeness, baryon number) are conserved locally in spatially restricted correlation clusters. Their size is determined by two time scales: the equilibration time specifying the formation of a quark-gluon plasma, and the hadronization time, specifying the onset of confinement. The expected values for these scales provide the theoretical basis for the suppression observed for strangeness production in elementary interactions ($pp$, $e^+e^-$) below LHC energies. In contrast, the space-time superposition of individual collisions in high energy heavy ion interactions leads to higher energy densities, resulting in much later hadronization and hence much larger hadronization volumes. This largely removes the causality constraints and results in an ideal hadronic resonance gas in full chemical equilibrium. In the present paper, we det...
Incompressibility of strange matter
Sinha, M N; Dey, J; Dey, M; Ray, S; Bhowmick, S; Sinha, Monika; Bagchi, Manjari; Dey, Jishnu; Dey, Mira; Ray, Subharthi; Bhowmick, Siddhartha
2002-01-01
Strange stars calculated from a realistic equation of state (EOS) show compact objects in the mass radius curve, when they are solved for gravitational fields via TOV equation. Many of the observed stars seem to fit in with this kind of compactness irrespective of whether they are X-ray pulsars, bursters or soft $\\gamma$ repeaters or radio pulsars. Calculated incompressibility of this strange matter shows continuity with that of nuclear matter. This is important in the cosmic separation of phase scenario. We compare our calculations of incompressibility with that of a nuclear matter EOS. This EOS has a continuous transition to ud-matter at about five times normal density. From a look at the consequent velocity of sound it is found that the transition to ud-matter seems necessary.
Strangeness in Nuclear Physics
Bydžovský, Petr
Košice: Slovak Physical Society, 2012 - (Reiffers, M.), s. 7-12 ISBN 978-80-970625-4-5. [17th Conference of Czech and Slovak Physicists. Žilina (SK), 05.09.2011-08.09.2011] R&D Projects: GA ČR GA202/08/0984 Institutional research plan: CEZ:AV0Z10480505 Keywords : strangeness production * hypernuclei * hyper electroproduction Subject RIV: BE - Theoretical Physics
Explosion of strange attractors exhibited by Duffing's equation
Recently chaotic behavior in deterministic systems attracts attention of researchers in various fields. By using analog and digital computers, the author has long been engaged himself in the investigation on this kind of motion exhibited by Duffing's equation and has called the phenomenon the chaotically transitional process. The chaotically transitional process is attributed to both the small uncertain factors in the physical system and the global structure of the solutions of the equation. This paper also deals with chaotically transitional processes exhibited by Duffing's equation. The results obtained in the series of our reports and the unsolved problems developed from them are summarized. Special attention is directed towards the transition of the processes under the variation of the system parameter. The explosion of the strange attractor, i.e., an interesting type of transition from strange to strange attractor has been made clear. (author)
Strangeness production in AA and pp collisions
Castorina, Paolo; Satz, Helmut
2016-07-01
Boost-invariant hadron production in high-energy collisions occurs in causally disconnected regions of finite space-time size. As a result, globally conserved quantum numbers (charge, strangeness, baryon number) are conserved locally in spatially restricted correlation clusters. Their size is determined by two time scales: the equilibration time specifying the formation of a quark-gluon plasma, and the hadronization time, specifying the onset of confinement. The expected values for these scales provide the theoretical basis for the suppression observed for strangeness production in elementary interactions ( pp , e^+e^- below LHC energies. In contrast, the space-time superposition of individual collisions in high-energy heavy-ion interactions leads to higher energy densities, resulting in much later hadronization and hence much larger hadronization volumes. This largely removes the causality constraints and results in an ideal hadronic resonance gas in full chemical equilibrium. In the present paper, we determine the collision energies needed for that; we also estimate when pp collisions reach comparable hadronization volumes and thus determine when strangeness suppression should disappear there as well.
Nucleon Strangeness and Unitarity
Musolf, M. J.; Hammer, H. -W.; D. Drechsel(Institut f. Kernphysik, Mainz)
1996-01-01
The strange-quark vector current form factors of the nucleon are analyzed within the framework of dispersion relations. Particular attention is paid to contributions made by $K\\bar{K}$ intermediate states to the form factor spectral functions. It is shown that, when the $K\\bar{K}\\to N\\bar{N}$ amplitude is evaluated in the Born approximation, the $K\\bar{K}$ contributions are identical to those arising from a one-loop calculation and entail a serious violation of unitarity. The mean square stra...
Strangeness production in proton-proton and proton-nucleus collisions
Shyam, Radhey
2005-01-01
In these lectures we discuss the investigation of the strange meson production in proton-proton ($pp$) and in proton-nucleus ($pA$) reactions within an effective Lagrangian model. The kaon production proceeds mainly via the excitations of $N^*$(1650), $N^*$(1710), and $N^*$(1720) resonant intermediate nucleonic states, in the collision of two initial state nucleons. Therefore, the strangeness production is expected to provide information about the resonances lying at higher excitation energie...
Strange baryon resonance production in $\\sqrt{s_{NN}} = 200$ GeV $p+p$ and $Au+Au$ collisions
Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Bezverkhny, B I; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, C O; Blyth, S L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Choi, H A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; Dedovich, T G; De Phillips, M; Derevshchikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta-Majumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Gaudichet, L; Ghazikhanian, V; Ghosh, P; González, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guimaraes, K S F F; Guo, Y; Gupta, N; Gutíerrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Krämer, M; Kravtsov, P; Kravtsov, V I; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; La Pointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C H; Lehocka, S; Le Vine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimansky, S S; ESichtermann; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van, G; Buren; Van der Kolk, N; Van Leeuwen, M; Van der Molen, A M; Varma, R; Vasilevski, I M; Vasilev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N
2006-01-01
We report the measurements of $\\Sigma (1385)$ and $\\Lambda (1520)$ production in $p+p$ and $Au+Au$ collisions at $\\sqrt{s_{NN}} = 200$ GeV from the STAR collaboration. The yields and the transverse momentum spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central $Au+Au$ collisions. Our results indicate that there may be a time-span between chemical and thermal freeze-out during which elastic hadronic interactions occur.
Signature of strange dibaryon in kaon-induced reaction
Ohnishi, Shota; Kamano, Hiroyuki; Sato, Toru
2011-01-01
We examine how the signature of the strange-dibaryon resonances in the barKNN-piSigmaN system shows up in the scattering amplitude on the physical real energy axis within the framework of Alt-Grassberger-Sandhas (AGS) equations. The so-called point method is applied to handle the three-body unitarity cut in the amplitudes. We also discuss the possibility that the strange-dibaryon production reactions can be used for discriminating between existing models of the two-body barKN-piSigma system with Lambda(1405).
Leer, Jonatan; Kjær, Katrine Meldgaard
chefs Jamie Oliver and Gordon Ramsay imagine, meet and evaluate the ‘other’ food cultures in these programs, paying special attention to how the encounter with the local Indian and Italian is imagined to be a gateway to an authentic and/or primitive experience. To unpack the programs and the experiences...... unpacking cultural encounters, and show how we have used it to deconstruct how ‘authentic’ food is done and met in Gordon's Great Escape and Jamie's Italian Escape. In doing so, we will argue that this way of reading cultural encounters ultimately opens for an alternative understanding of the central......Strange Culinary Encounters: Stranger Fetishism in Cooking Shows In this paper, we will examine the ways in which the encountering of 'other' food cultures is played out in the two travelogue cooking shows Gordon's Great Escape and Jamie's Italian Escape, arguing that despite their ‘noble...
Steinheimer, J.; Sturm, C.; Schramm, S.; Stöcker, H.
2010-09-01
Adjacent to the existing accelerator complex of the GSI Helmholtz Centre for Heavy Ion Research at Darmstadt, Germany, the Facility for Antiproton and Ion Research (FAIR) substantially expands research goals and technical possibilities. It will provide worldwide unique accelerator and experimental facilities allowing for a large variety of unprecedented fore-front research in hadron, nuclear and atomic physics as well as applied sciences which will be described briefly in this paper. The start version of FAIR, the so-called Modularized Start Version, will deliver first beams in 2017/2018. As an example the paper presents research efforts on strangeness at FAIR using heavy ion collisions, exotic nuclei from fragmentation and antiprotons to tackle various topics in this area. In particular hypernuclei and metastable exotic multi-hypernuclear objects will be investigated.
Zero Sound in Strange Metallic Holography
Hoyos-Badajoz, Carlos; Wu, Jackson M S
2010-01-01
One way to model the strange metal phase of certain materials is via a holographic description in terms of probe D-branes in a Lifshitz spacetime, characterised by a dynamical exponent z. The background geometry is dual to a strongly-interacting quantum critical theory while the probe D-branes are dual to a finite density of charge carriers that can exhibit the characteristic properties of strange metals. We compute holographically the low-frequency and low-momentum form of the charge density and current retarded Green's functions in these systems for massless charge carriers. The results reveal a quasi-particle excitation when z<2, which in analogy with Landau Fermi liquids we call zero sound. The real part of the dispersion relation depends on momentum k linearly, while the imaginary part goes as k^2/z. When z is greater than or equal to 2 the zero sound is not a well-defined quasi-particle. We also compute the frequency-dependent conductivity in arbitrary spacetime dimensions. Using that as a measure of...
Solid Bare Strange Quark Stars
Xu, R X
2003-01-01
The reason, we need three terms of `strange', `bare', and `solid' before quark stars, is presented concisely though some fundamental issues are not certain. Observations favoring these stars are introduced.
Search for strange quark matter
Hill, J C
2000-01-01
We present results of a search for charged and neutral strangelets produced on collisions of 11.6 A GeV/c Au beams with Pt or Pb targets. Yields of light nuclei and hypernuclei produced by coalescence were measured. Penalty factors were measured for the addition to a fragment of a nucleon or strange hadron. These are useful in planning future searches for strange quark matter.
Chiral symmetry and strangeness at SIS energies
In this talk we review the consequences of the chiral SU(3) symmetry for strangeness propagation in nuclear matter. Objects of crucial importance are the meson-baryon scattering amplitudes obtained within the chiral coupled-channel effective field theory. Results for antikaon and hyperon-resonance spectral functions in cold nuclear matter are presented and discussed. The importance of the Σ(1385) resonance for the subthreshold antikaon production in heavy-ion reaction at SIS is pointed out. The in-medium properties of the latter together with an antikaon spectral function based on chiral SU(3) dynamics suggest a significant enhancement of the π Λ → anti Κ N reaction in nuclear matter. (orig.)
Strangeness and charm in nuclear matter
Tolos, Laura; Cabrera, Daniel; Garcia-Recio, Carmen; Molina, Raquel; Nieves, Juan; Oset, Eulogio; Ramos, Angels; Romanets, Olena; Salcedo, Lorenzo Luis
2013-09-01
The properties of strange (K, Kbar and K) and open-charm (D, Dbar and D*) mesons in dense matter are studied using a unitary approach in coupled channels for meson-baryon scattering. In the strangeness sector, the interaction with nucleons always comes through vector-meson exchange, which is evaluated by chiral and hidden gauge Lagrangians. For the interaction of charmed mesons with nucleons we extend the SU(3) Weinberg-Tomozawa Lagrangian to incorporate spin-flavor symmetry and implement a suitable flavor symmetry breaking. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects and meson self-energies. On one hand, we obtain the K, Kbar and K spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also make an estimate of the transparency ratio of the γA→K+KA‧ reaction, which we propose as a tool to detect in-medium modifications of the K meson. On the other hand, in the charm sector, several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2+ and 3/2+ baryons. The properties of these states in matter are analyzed and their influence on the open-charm meson spectral functions is studied. We finally discuss the possible formation of D-mesic nuclei at FAIR energies.
Production of strange particles in hadronization processes
Strange particles provide an important tool for the study of the color confinement mechanisms involved in hadronization processes. We review data on inclusive strange-particle production and on correlations between strange particles in high-energy reactions, and discuss phenomenological models for parton fragmentation. 58 refs., 24 figs
The strange axial-vector mesons K1 (1270) and K1 (1400) are reanalyzed in the light of the updated experimental information and compared with the recent result on the Kππ production in τ decay. The mixing angle between the strange mesons of 3P1 and 1P1 is determined by the partial decay rates, and, independently, by the masses. They lead to θK∼33 degree or 57 degree. The observed K1 (1400) production dominance in the τ decay favors θK∼33 degree. Flavor-SU(3) breaking of 20% or so in the production amplitudes can explain quantitatively the observed production ratio
Topics in strangeness nuclear physics
Strangeness nuclear physics bears a broad impact on contemporary physics since it lies at the intersection of nuclear and elementary particle physics, having, moreover, significant implications to the astrophysics of compact objects. This set of extensive lectures presents a balanced theoretical and experimental introduction to, and survey of, the field, addressing topics such as the production and spectroscopy of strange nuclear systems, modern approaches to the hyperon-nucleon interaction, and weak decays of hypernuclei. With new experiments underway, this burgeoning research field is well served by this tutorial primer and review for both newcomers and seasoned researchers alike. (orig.)
Will strangeness win the prize?
Kapusta, Joseph I. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States). E-mail: kapusta at physics.spa.umn.edu
2001-03-01
Five groups have made predictions involving the production of strange hadrons and entered them in a competition set up by Barbara Jacak, Xin-Nian Wang and myself in the spring of 1998 for the purpose of comparing with first-year physics results from RHIC. These predictions are summarized and evaluated. (author)
Will strangeness win the prize?
Five groups have made predictions involving the production of strange hadrons and entered them in a competition set up by Barbara Jacak, Xin-Nian Wang and myself in the spring of 1998 for the purpose of comparing with first-year physics results from RHIC. These predictions are summarized and evaluated. (author)
Will Strangeness Win the Prize?
Kapusta, Joseph I.
2000-01-01
Five groups have made predictions involving the production of strange hadrons and entered them in a competition set up by Barbara Jacak, Xin-Nian Wang and myself in the spring of 1998 for the purpose of comparing to first year physics results from RHIC. These predictions are summarized and evaluated.
O'Raifeartaigh, Cormac
2012-11-01
Not many life stories in physics involve Nazis, illicit sex, a strange cat and the genetic code. Thus, a new biography of the great Austrian physicist Erwin Schrödinger is always of interest, and with Erwin Schrödinger and the Quantum Revolution, veteran science writer John Gribbin does not disappoint.
Recent experimental and theoretical advances in hypernuclear physics are reviewed. An appraisal is given of various suggestions for using strange probes to test partial quark deconfinement in nuclei and meson exchange vs quark-gluon exchange descriptions of baryon-baryon interactions. 76 refs., 6 figs
Torsional oscillations of strange stars
Mannarelli Massimo
2014-01-01
Full Text Available Strange stars are one of the hypothetical compact stellar objects that can be formed after a supernova explosion. The existence of these objects relies on the absolute stability of strange collapsed quark matter with respect to standard nuclear matter. We discuss simple models of strange stars with a bare quark matter surface, thus standard nuclear matter is completely absent. In these models an electric dipole layer a few hundreds Fermi thick should exist close to the star surface. Studying the torsional oscillations of the electrically charged layer we estimate the emitted power, finding that it is of the order of 1045 erg/s, meaning that these objects would be among the brightest compact sources in the heavens. The associated relaxation times are very uncertain, with values ranging between microseconds and minutes, depending on the crust thickness. Although part of the radiated power should be absorbed by the electrosphere surrounding the strange star, a sizable fraction of photons should escape and be detectable.
K^* Mesons and Nucleon Strangeness
Barz, L. L.; Forkel, H.; Hammer, H. -W.; Navarra, F. S.; Nielsen, M; Ramsey-Musolf, M. J.
1998-01-01
We study contributions to the nucleon strange quark vector current form factors from intermediate states containing K^* mesons. We show how these contributions may be comparable in magnitude to those made by K mesons, using methods complementary to those employed in quark model studies. We also analyze the degree of theoretical uncertainty associated with K^* contributions.
Strangeness exchange reactions and hypernuclei
Recent progress in the spectroscopy of Λ and Σ hypernuclei is reviewed. Prospects for the production of doubly strange hypernuclei at a future kaon factory are assessed. It is suggested that the (K-,K+) reaction on a nuclear target may afford an optimal way of producing the H dibaryon, a stable six quark object with J/sup π/ = O+, S = -2
D I Salmov; T Babacan; A Kücükbursa; S Ünlü; İ Maraṣ
2006-06-01
Within the framework of quasiparticle random phase approximation (QRPA), Pyatov–Salamov method [23] for the self-consistent determination of the isovector effective interaction strength parameter, restoring a broken isotopic symmetry for the nuclear part of the Hamiltonian, is used. The isospin admixtures in the ground state of the parent nucleus, and the isospin structure of the isobar analog resonance (IAR) state were investigated with the inclusion of the pairing correlations between nucleons for the medium and heavy mass regions: 80 < < 90, 102 < < 124, and 204 < < 214. It was determined that the influence of the pairing interaction between nucleons on the isospin admixtures in the ground state and the isospin structure of the IAR state is more pronounced for the light isotopes ( ≈ ) of the investigated nuclei.
Chang, Yue; Sun, C. P.
2011-01-01
We study a hybrid nano-mechanical system coupled to a spin ensemble as a quantum simulator to favor a quantum interference effect, the electromagnetically induced transparency (EIT). This system consists of two nano-mechanical resonators (NAMRs), each of which coupled to a nuclear spin ensemble. It could be regarded as a crucial element in the quantum network of NAMR arrays coupled to spin ensembles. Here, the nuclear spin ensembles behave as a long-lived transducer to store and transfer the ...
Strangeness physics in electron scattering experiments at the Mainz Microtron
Present and future research into the electro-production of kaons plays an important role at Mainz Microtron MAMI. With the KAOS spectrometer employed for kaon detection in the multi-spectrometer facility, cross section and single-spin asymmetry measurements of the elementary p(e, e'K+)Λ, Σ0 reactions at low four-momentum transfers have been performed, followed by pioneering experiments on the pion-decay spectroscopy of light Λ-hypernuclei. The elementary studies are important for the understanding of the effective coupling of photons to the hadrons and their resonances and electromagnetic form factors involved in the process. Isobar and Regge-plus-resonance models were compared with the data. The measurements have clearly discriminated between effective Lagrangian models for photo- and electro-production of strangeness. In 2011 the worldwide first precision decay-pion spectroscopy experiments of electro-produced strange nuclear systems have been performed. Comparing mass measurements and structure information on light Λ-hypernuclei with modern ab initio calculations will help to accurately determine the YN interactions and the role of three-body forces. The physics of strangeness in hadronic systems is a continuously developing field with different experimental approaches exploited in precision electron scattering measurements at MAMI. (author)
Hayai, Aya; Maeda, Yusuke; Ueno, Yoshihito
2016-08-01
Here, we report the synthesis of a fluorescence resonance energy transfer (FRET)-based probe for single nucleotide polymorphism (SNP) typing. The probe contains a fluorescent tricyclic base, 8-amino-3-(2,3-dihydroxypropyl)imidazo[4',5':5,6]pyrido[2,3-d]pyrimidine, as a donor molecule and 7-diethylaminocoumarin-3-carboxylic acid as an acceptor molecule. FRET was observed between the donor and acceptor molecules on the probe. The identity of the target bases on DNA and RNA strands could be determined using the probe. PMID:27329795
Strangeness and charm in nuclear matter
Tolos, Laura, E-mail: tolos@ice.csic.es [Instituto de Ciencias del Espacio (IEEC/CSIC), Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain); Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Cabrera, Daniel [Departamento de Física Teórica II, Universidad Complutense, 28040 Madrid (Spain); Garcia-Recio, Carmen [Departamento de Física Atómica, Molecular y Nuclear, and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada (Spain); Molina, Raquel [Research Center for Nuclear Physics (RCNP), Mihogaoka 10-1, Ibaraki 567-0047 (Japan); Nieves, Juan; Oset, Eulogio [Instituto de Física Corpuscular (Centro Mixto CSIC-UV), Institutos de Investigación de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, Angels [Departament d' Estructura i Constituents de la Matèria, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Romanets, Olena [Theory Group, KVI, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Salcedo, Lorenzo Luis [Departamento de Física Atómica, Molecular y Nuclear, and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada (Spain)
2013-09-20
The properties of strange (K, K{sup ¯} and K{sup ¯⁎}) and open-charm (D, D{sup ¯} and D{sup ⁎}) mesons in dense matter are studied using a unitary approach in coupled channels for meson–baryon scattering. In the strangeness sector, the interaction with nucleons always comes through vector-meson exchange, which is evaluated by chiral and hidden gauge Lagrangians. For the interaction of charmed mesons with nucleons we extend the SU(3) Weinberg–Tomozawa Lagrangian to incorporate spin–flavor symmetry and implement a suitable flavor symmetry breaking. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects and meson self-energies. On one hand, we obtain the K, K{sup ¯} and K{sup ¯⁎} spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also make an estimate of the transparency ratio of the γA→K{sup +}K{sup ⁎−}A{sup ′} reaction, which we propose as a tool to detect in-medium modifications of the K{sup ¯⁎} meson. On the other hand, in the charm sector, several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2{sup +} and 3/2{sup +} baryons. The properties of these states in matter are analyzed and their influence on the open-charm meson spectral functions is studied. We finally discuss the possible formation of D-mesic nuclei at FAIR energies.
Strange functions in real analysis
Kharazishvili, AB
2005-01-01
Weierstrass and Blancmange nowhere differentiable functions, Lebesgue integrable functions with everywhere divergent Fourier series, and various nonintegrable Lebesgue measurable functions. While dubbed strange or "pathological," these functions are ubiquitous throughout mathematics and play an important role in analysis, not only as counterexamples of seemingly true and natural statements, but also to stimulate and inspire the further development of real analysis.Strange Functions in Real Analysis explores a number of important examples and constructions of pathological functions. After introducing the basic concepts, the author begins with Cantor and Peano-type functions, then moves to functions whose constructions require essentially noneffective methods. These include functions without the Baire property, functions associated with a Hamel basis of the real line, and Sierpinski-Zygmund functions that are discontinuous on each subset of the real line having the cardinality continuum. Finally, he considers e...
Spectrum of hadrons with strangeness
Chen, Chen; Roberts, Craig D; Wan, Shaolong; Wilson, David J
2012-01-01
We describe a calculation of the spectrum of strange and nonstrange hadrons that simultaneously correlates the dressed-quark-core masses of meson and baryon ground- and excited-states within a single framework. The foundation for this analysis is a symmetry-preserving Dyson-Schwinger equation treatment of a vector-vector contact interaction. Our results exemplify and highlight the deep impact of dynamical chiral symmetry breaking on the hadron spectrum: an accurate description of the meson spectrum entails a similarly successful prediction of the spectrum of baryons, including those with strangeness. The analysis also provides numerous insights into baryon structure. For example, that baryon structure is largely flavour-blind, the first radial excitation of ground-state baryons is constituted almost entirely from axial-vector diquark correlations, and DCSB is the foundation for the ordering of low-lying baryon levels; viz., (1/2)^+, (1/2)^+, (1/2)^-.
Neutral strange particle production in π-p interactions at 100 GeV/c
Production mechanisms in the single- and double-particle inclusive interactions: π- p → K/sup O//sub s/ + X, LAMBDA0 + X, K0/sub s/ + π/sup +-/ + X, and LAMBDA0 + π/sup +-/ + X were studied including cluster effects, resonance, and rapidity correlations. A search was made for K* and Σ* resonances by examining effective mass distributions. It is found that the production of strange particles is not dominated by low mass resonances
Chiral Primaries in Strange Metals
Isachenkov, Mikhail(DESY Hamburg, Theory Group, Notkestrasse 85, D-22607 Hamburg, Germany); Kirsch, Ingo; Schomerus, Volker
2014-01-01
It was suggested recently that the study of 1-dimensional QCD with fermions in the adjoint representation could lead to an interesting toy model for strange metals and their holographic formulation. In the high density regime, the infrared physics of this theory is described by a constrained free fermion theory with an emergent N=(2,2) superconformal symmetry. In order to narrow the choice of potential holographic duals, we initiate a systematic search for chiral primaries in this model. We a...
Search for strange dibaryon systems
The authors present preliminary results of an experiment which is being run at the CERN Proton Synchrotron (PS). The experiment is designed to search for dibaryon systems with strangeness -2, produced in the reaction K- + d→K+ + MM at 1.4 GeV/c incident K- momentum. The missing mass (MM) sensitivity ranges from 2.1 up to 2.4 GeV/c2, the resolution being approximately +- 3.5 MeV/c2. (Auth.)
Sitton, Christina M.
2014-01-01
Fragmentation is a basic symptom of loss, and poetry naturally reflects this disjointing and destructive effect. The fracturing within the poetic form reflects the internal and repeated fracturing effects of trauma on one's own life. In this poetry collection, A Strange Kind of Dying, the speaker is bound by the question, "How is it that I can piece myself back together?" The collection of poetry is meant to help the speaker to find healing from the fragmentation through language. The work is...
A Strange Star Model for Pulsars
Xu, Ren Xin; Qiao, Guo Jun
1998-01-01
It is suggested in this paper that the `bare' strange star might be not bare, and there could be a magnetosphere around it. As a strange star might be an intensely magnetized rotator, the induced unipolar electric field would be large enough to construct a magnetosphere around the strange matter core. This kind of magnetosphere is very similar to that of the rotating magnetized neutron stars discussed by many authors. A magnetosphere will be established very soon through pair production by ga...
2002-01-01
With the exception of the deuteron, no bound state and only a few possible resonances have been reported in dibaryon systems. The best known of these is a $\\Lambda p$ enhancement which has been reported at several energies. In a recent experiment on the reaction $K^{-}d \\rightarrow \\Lambda p\\pi^{-}$ this shows up as a narrow peak (M=2129 MeV, $\\Gamma$=5.4 $\\pm$ 1.7 MeV) produced near minimum transfer of the dibaryon system. \\\\ \\\\ It is proposed to study S=-2 dibaryon systems such as ($\\Xi N$ and $\\Sigma\\Lambda$). The fast forward $K^{+}$ from the reaction \\\\ \\\\ $K^{-}d \\rightarrow K^{+}\\Sigma^{-}\\Lambda$ or $K^{+}\\Xi^{-}n$ \\\\ \\\\ will be investigated with Cerenkov counters and a magnetic spectrometer. The missing mass will be measured. Information from time-of-flight measurements will also be used to help select events and reduce background. A deuterium target will be exposed to a separated $K^{-}$ counter beam with a momentum of 1.4 GeV/c. This experiment will study the possible existence of the S=-2 dibaryon...
Packwood, Daniel M
2012-01-01
We study a gas containing two components, a small component P and a large component Q. P is selectively heated to a high temperature and then returns to equilibrium via collisions with Q. This thermal equilibration process is analysed in a new way. We divide the kinetic energy space of the molecules of P into two regions F and D, and show that the molecules of P randomly switch (`oscillate') between the two states as time proceeds due to collisions with the molecules of Q. Initially, the molecules of P are all in the state D, however because each molecule in P collides with the molecules of Q at different times, the oscillations occur out of step with each other. There is a net destructive interference between the oscillations, and so they are not observed when monitoring the average kinetic energy of the molecules of P as a function of time. We will explain the similarities and differences between this observation and transverse relaxation processes that occur in magnetic resonance spectroscopy. This study e...
Strangeness detection in ALICE experiment at LHC
Safarik, K. [European Lab. for Particle Physics, Geneva (Switzerland)
1995-07-15
The authors present some parameters of the ALICE detector which concern the detection of strange particles. The results of a simulation for neutral strange particles and cascades, together with estimated rates are presented. They also briefly discuss the detection of charged K-mesons. Finally, they mention the possibility of open charm particle detection.
Strange attractor simulated on a quantum computer
M. Terraneo; Georgeot, B.; D.L. Shepelyansky
2002-01-01
We show that dissipative classical dynamics converging to a strange attractor can be simulated on a quantum computer. Such quantum computations allow to investigate efficiently the small scale structure of strange attractors, yielding new information inaccessible to classical computers. This opens new possibilities for quantum simulations of various dissipative processes in nature.
Final states with strangeness from Crystal Barrel and Asterix
We discuss φ production in anti pp annihilation at rest from the Asterix and Crystal Barrel experiments and compare the branching ratios to similar final states without strangeness. The ωπ0/φπ0 production ratio is unexpectedly low. In the search for new states, the φπ0 mass spectrum shows no evidence for a resonance in the 1450 MeV/c2 mass range but the K*K0π0 Dalitz plot shows interesting structure. (orig.)
Strangeness Production and Ultrarelativistic Cascades
Kahana, D E
1998-01-01
A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy ion-ion collisions is applied to the production of strangeness at SPS energies $\\sqrt{s}=17-20$. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons, including strange mesons, by separating the dynamics into two steps, a fast cascade involving only nucleons in the original colliding relativistic ions followed, after an appropriate delay, by multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS. A byproduct, obtained here in preliminary calculations, is a description of str...
Precision measurements of the weak force suggest that strange quarks have an influence on the magnetic moment of the proton, as Krishna Kumar explains. In the 1980s experiments performed by the European Muon Collaboration at CERN showed that the spin of the proton - that is its intrinsic angular momentum - could not be explained by simply adding together the spins of its constituent quarks (which have a magnitude of 1/2 in units of Planck's constant). Instead, researchers found that 'up' and 'down' quarks contributed less than 25% to the spin of the proton (which also has a magnitude of 1/2). It has long been thought that the presence of strange quarks inside the proton might partly explain this 'spin crisis'. These quarks, which are heavier than up and down quarks, are typically observed only in high-energy cosmic rays or particle accelerators, not in the everyday nuclei that make up the world around us. However, the force that holds the quarks together inside protons and other particles is so strong that the uncertainty principle allows quark-antiquark pairs to spontaneously appear from the vacuum and then disappear a short time later. The question is, do these ephemeral 'sea quarks' contribute to the observed properties of the proton, such as its mass, charge, spin and magnetic moment? A series of experimental results, most recently from the Jefferson Laboratory in the US, now seems poised to provide a definitive answer to this question. (U.K.)
Naumov, D V; Naumova, E; Popov, B; Astier, Pierre; Autiero, D; Baldisseri, Alberto; Baldo-Ceolin, Massimilla; Banner, M; Bassompierre, G; Benslama, K; Besson, N; Bird, I; Blumenfeld, B; Bobisut, F; Bouchez, J; Boyd, S; Bueno, A G; Bunyatov, S; Camilleri, L L; Cardini, A; Cattaneo, P W; Cavasinni, V; Cervera-Villanueva, A; Challis, R C; Collazuol, G; Conforto, G; Conta, C; Contalbrigo, M; Cousins, R; Daniels, D; Das, R; Degaudenzi, H M; Del Prete, T; De Santo, A; Dignan, T; Di Lella, L; do Couto e Silva, E; Dumarchez, J; Ellis, M; Feldman, G J; Ferrari, R; Ferrère, D; Flaminio, V; Fraternali, M; Gaillard, J M; Gangler, E; Geiser, A; Geppert, D; Gibin, D; Gninenko, S; Godley, A; Gómez-Cadenas, J J; Gosset, J; Gössling, C; Gouanère, M; Grant, A; Graziani, G; Guglielmi, A M; Hagner, C; Hernando, J; Hong, T M; Hubbard, D B; Hurst, P; Hyett, N; Iacopini, E; Joseph, C L; Juget, F R; Kent, N; Kirsanov, M; Klimov, O; Kokkonen, J; Kovzelev, A; Krasnoperov, A V; Lacaprara, S; Lachaud, C; Lakic, B; Lanza, A; La Rotonda, L; Laveder, M; Letessier-Selvon, A A; Lévy, J M; Linssen, Lucie; Ljubicic, A; Long, J; Lupi, A; Lyubushkin, V V; Marchionni, A; Martelli, F; Méchain, X; Mendiburu, J P; Meyer, J P; Mezzetto, Mauro; Mishra, S R; Moorhead, G F; Nédélec, P; Nefedov, Yu A; Nguyen-Mau, C; Orestano, D; Pastore, F; Peak, L S; Pennacchio, E; Pessard, H; Petti, R; Placci, A; Polesello, G; Pollmann, D; Polyarush, A Yu; Poulsen, C; Rebuffi, L; Rico, J; Roda, C; Rubbia, André; Salvatore, F; Schahmaneche, K; Schmidt, B; Schmidt, T; Sconza, A; Sevior, M E; Shih, D; Sillou, D; Soler, F J P; Sozzi, G; Steele, D; Stiegler, U; Stipcevic, M; Stolarczyk, T; Tareb-Reyes, M; Taylor, G N; Tereshchenko, V V; Toropin, A N; Touchard, A M; Tovey, Stuart N; Tran, M T; Tsesmelis, E; Ulrichs, J; Vacavant, L; Valdata-Nappi, M; Valuev, V Yu; Vannucci, François; Varvell, K E; Veltri, M; Vercesi, V; Vidal-Sitjes, G; Vieira, J M; Vinogradova, T G; Weber, F V; Weisse, T; Wilson, F F; Winton, L J; Yabsley, B D; Zaccone, Henri; Zuber, K; Zuccon, P
2004-01-01
Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.
Nucleon Vector Strangeness Form Factors: Multi-pion Continuum and the OZI Rule
Hammer, H. -W.; Ramsey-Musolf, M. J.
1997-01-01
We estimate the 3 \\pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \\pi \\rho \\pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to that of typical OZI-allowed contributions. We also study the isoscalar electromagnetic form factors, and find that the presence of a \\rho \\pi resonance in the multi-pion continuum may generate an appreciable contribution.
Shi, Shusu
2016-01-01
Strange hadrons, especially multi-strange hadrons are good probes for the early partonic stage of heavy ion collisions due to their small hadronic cross sections. In this paper, I give a brief review on the elliptic flow measurements of strange and multi-strange hadrons in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC).
Strange anti-baryons---QGP versus HC
We study quark-gluon plasma (QGP) and hadronic gas (HG) models of the central fireball presumed to be the source of abundantly produced strange (anti-)baryons in S→W collisions at 200 GeV A. We consider how multi-strange (anti-)baryon multiplicities depend on strangeness conservation and compare the HG and QGP fireball scenarios. We argue that the total particle multiplicity emerging from the central rapidity region as well as the variation of production rates with changes in the beam energy allows to distinguish between the two reaction scenarios
Bottom-strange mesons in hyperonic matter
Pathak, Divakar; Mishra, Amruta
2014-01-01
The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of t...
Poelstra, Klaas; Prakash, Jai; Beljaars, Eleonora; Bansal, Ruchi
2015-01-01
The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least
Poelstra, Klaas; Prakash, Jai; Beljaars, Leonie; Bansal, Ruchi
2010-01-01
The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least
Strange attractors in rattleback dynamics
Borisov, Aleksei V; Mamaev, Ivan S [Institute of Computer Science, Izhevsk (Russian Federation)
2003-04-30
This review is dedicated to the dynamics of the rattleback, a phenomenon with curious physical properties that is studied in nonholonomic mechanics. All known analytical results are collected here, and some results of our numerical simulation are presented. In particular, three-dimensional Poincare maps associated with dynamical systems are systematically investigated for the first time. It is shown that the loss of stability of periodic and quasiperiodic solutions, which gives rise to strange attractors, is typical of the three-dimensional maps related to rattleback dynamics. This explains some newly discovered properties of the rattleback related to the transition from regular to chaotic solutions at certain values of the physical parameters. (methodological notes)
Ultrarelativistic cascades and strangeness production
Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.
1998-08-24
A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies {radical}(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.) 26 refs.
Ultrarelativistic cascades and strangeness production
A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies √(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.)
Ultrarelativistic cascades and strangeness production
Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Physics Dept.; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.
1998-02-01
A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS.
Chaos, turbulence and strange attractors
Using the turbulence example, the author recalls the two different conceptions of the nature of an erratic regime: the one in which a great number of elementary events are concerned (Landau) and the other one in which, on the contrary, a few number of elementary events are concerned (Ruelle and Takens). The last type of erratic comportment has a deterministic origin and is pointed by the adjective chaotic. Phase space for a dynamic system is presented and so the attractor nation. Chaos and notion of sensitiveness to initial conditions are defined. In scrutining the geometry of an attractor corresponding to a chaotic regime, the notion of strange attractor is shown. Some experiments results are given as illustration. Application field is recalled: for example, studies on hamiltonian chaos are made at DRFC (Department of research on controlled fusion at CEA) in relation with plasma instabilities
Charm and Strangeness with Heavy-Quark Spin Symmetry
Tolos, L; Nieves, J; Romanets, O; Salcedo, L L
2012-01-01
We study charmed and strange baryon resonances that are generated dynamically within a unitary meson-baryon coupled-channel model which incorporates heavy-quark spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa chiral Lagrangian to SU(8) spin-flavor symmetry and implementing a strong flavor symmetry breaking. The model generates dynamically resonances with negative parity in all the isospin, spin, and strange and charm sectors that one can form from an s-wave interaction between pseudoscalar and vector meson multiplets with $1/2^+$ and $3/2^+$ baryons. Our results are compared with experimental data from several facilities as well as with other theoretical models. Moreover, we obtain the properties of charmed pseudoscalar and vector mesons in dense matter within this coupled-channel unitary effective model by taking into account Pauli-blocking effects and meson self-energies in a self-consistent manner. We obtain the open-charm meson spectral functions in this dense nuclear environm...
Overview of the electromagnetic production of strange mesons at MAMI
The Mainz Microtron MAMI provides a continuous-wave unpolarized or spin-polarized electron beam with energies up to 1.6 GeV and high degrees of polarization. Electro-production of strange mesons is performed in the multi-spectrometer facility with the KAOS spectrometer for kaon detection and a high-resolution spectrometer for electron detection in plane or out of plane. Differential cross section measurements of exclusive p(e,e′K+)Λ,Σ0 reactions at low four-momentum transfers in the nucleon's third resonance region have been done, followed by a measurement of the beam helicity asymmetry for p(e→,e′K+)Λ. These studies are important for the understanding of the effective coupling of photons to the hadrons and their resonances and electromagnetic form factors entering different effective Lagrangian models for photo- and electro-production of strangeness. The polarized structure function, extracted from the beam helicity asymmetry, shows an especially high sensitivity to model parameters
Zero sound in strange metals with hyperscaling violation from holography
Dey, Parijat
2013-01-01
Hyperscaling violating `strange metal' phase of heavy fermion compounds can be described holographically by probe D-branes in the background of a Lifshitz space-time (dynamical exponent $z$ and spatial dimensions $d$) with hyperscaling violation (corresponding exponent $\\theta$). Without the hyperscaling violation, strange metals are known to exhibit zero sound mode for $z<2$ analogous to the Fermi liquids. In this paper, we study its fate in the presence of hyperscaling violation and find that in this case the zero sound mode exists for $z < 2(1+|\\theta|/d)$, where the positivity of the specific heat and the null energy condition of the background dictate that $\\theta<0$ and $z\\geq 1$. However, for $z \\geq 2(1+|\\theta|/d)$, there is no well-defined quasiparticle for the zero sound. The systems behave like Fermi liquid for $2|\\theta|=dz$ and like Bose liquid for $2|\\theta| = qdz$ (where $q$ is the number of spatial dimensions along which D-branes are extended in the background space), but in general ...
Strange particle production from SIS to LHC
H Oeschler; J Cleymans; K Redlich
2003-05-01
A review of meson emission in heavy-ion collisions at incident energies from SIS up to collider energies is presented. A statistical model assuming chemical equilibrium and local strangeness conservation (i.e. strangeness conservation per collision) explains most of the observed features, e.g. the different centrality dependences of pions and kaons. Furthermore, the independence of the + to - ratio on the number of participating nucleons observed between SIS and relativistic heavy-ion collider (RHIC) is consistent with this model. The observed maximum in the +/+ excitation function is also seen in the ratio of strange to non-strange particle production. The appearance of this maximum around 30 A$\\cdot$GeV is due to the energy dependence of the chemical freeze-out parameters and .
Strangeness suppression in the unquenched quark model
Bijker, Roelof; Santopinto, Elena
2016-01-01
In this contribution, we discuss the strangeness suppression in the proton in the framework of the unquenched quark model. The theoretical results are in good agreement with the values extracted from CERN and JLab experiments.
Origin of isotopic spin and strangeness
An explanation of the origin of isotopic spin is given by applying the theory and calculations in the author's previous papers. An explanation of the origin of strangeness and broken SU3 is given as well
Associated strangeness production at intermediate energies
Elementary strangeness production reactions with hadronic and electromagnetic probes are briefly reviewed. Some recent theoretical and experimental findings are underlined and a few open questions are singled out. (author)
Strangeness suppression in the unquenched quark model
Bijker, Roelof; García-Tecocoatzi, Hugo; Santopinto, Elena
2016-07-01
In this contribution, we discuss the strangeness suppression in the proton in the framework of the unquenched quark model. The theoretical results are in good agreement with the values extracted from CERN and JLab experiments.
Surface photon emissivity of bare strange stars
Cheng, KS; Harko, T.
2003-01-01
We consider the bremsstrahlung surface photon emissivity of strange quark stars, by systematically taking into account the effects of the multiple scatterings of highly relativistic quarks in a dense medium (the Landau-Pomeranchuk-Migdal effect). Because of interference between amplitudes of nearby interactions, the bremsstrahlung emissivity from a strange star surface is suppressed for frequencies smaller than a critical frequency. The range of the suppressed frequencies is a function of the...
The strange asymmetry of the proton sea
We present a phenomenologically motivated parameterization of the s and s-bar parton distribution functions in the proton, calculated in the framework of the Meson Cloud Model. Parameters of the model have been fixed by comparing to a recent parameterization of the strange asymmetry of the proton sea, which has emerged from a global fit to Deep Inelastic Scattering data. The model reproduces quite well the the asymmetry of the strange sea of the proton.
Gaussian Anisotropy In Strange Quark Stars
Panahi, H.; Monadi, R.; Eghdami, I.
2015-01-01
In this paper for studying the anisotropic strange quark stars, we assume that the radial pressure inside the anisotropic star is a superposition of pressure in an isotropic case plus a Gaussian perturbation term. Considering a proportionality between electric charge density and the density of matter, we solve the TOV equation for different cases numerically. Our results indicate that anisotropy increases the maximum mass $M_{max}$ and also its corresponding radius $R$ for a typical strange q...
The Fastest Rotating Pulsar: a Strange Star?
徐仁新; 徐轩彬; 吴鑫基
2001-01-01
According to the observational limits on the radius and mass, the fastest rotating pulsar (PSR 1937+21) is probably a strange star, or at least some neutron star equations of state should be ruled out, if we suggest that a dipole magnetic field is relevant to its radio emission. We presume that the millisecond pulsar is a strange star with much low mass, small radius and weak magnetic moment.
an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to...... realize theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall...
Penta-quark States with Strangeness, Hidden Charm and Beauty
Wu, Jia-Jun
2015-01-01
The classical quenched quark models with three constituent quarks provide a good description for the baryon spatial ground states, but fail to reproduce the spectrum of baryon excited states. More and more evidences suggest that unquenched effects with multi-quark dynamics are necessary ingredients to solve the problem. Several new hyperon resonances reported recently could fit in the picture of penta-quark states. Based on this picture, some new hyperon excited states were predicted to exist; meanwhile with extension from strangeness to charm and beauty, super-heavy narrow $N^*$ and $\\Lambda^*$ resonances with hidden charm or beauty were predicted to be around 4.3 and 11 GeV, respectively. Recently, two of such $N^*$ with hidden charm might have been observed by the LHCb experiment. More of those states are expected to be observed in near future. This opens a new window in order to study hadronic dynamics for the multi-quark states.
Penta-Quark States with Strangeness, Hidden Charm and Beauty
Wu, Jia-Jun; Zou, Bing-Song
The classical quenched quark models with three constituent quarks provide a good description for the baryon spatial ground states, but fail to reproduce the spectrum of baryon excited states. More and more evidences suggest that unquenched effects with multi-quark dynamics are necessary ingredients to solve the problem. Several new hyperon resonances reported recently could fit in the picture of penta-quark states. Based on this picture, some new hyperon excited states were predicted to exist; meanwhile with extension from strangeness to charm and beauty, super-heavy narrow N* and Λ* resonances with hidden charm or beauty were predicted to be around 4.3 and 11 GeV, respectively. Recently, two of such N* with hidden charm might have been observed by the LHCb experiment. More of those states are expected to be observed in near future. This opens a new window in order to study hadronic dynamics for the multi-quark states.
Theoretical perspectives on strange physics
Kaons are heavy enough to have an interesting range of decay modes available to them, and light enough to be produced in sufficient numbers to explore rare modes with satisfying statistics. Kaons and their decays have provided at least two major breakthroughs in our knowledge of fundamental physics. They have revealed to us CP violation, and their lack of flavor-changing neutral interactions warned us to expect charm. In addition, K0-anti K0 mixing has provided us with one of our most elegant and sensitive laboratories for testing quantum mechanics. There is every reason to expect that future generations of kaon experiments with intense sources would add further to our knowledge of fundamental physics. This talk attempts to set future kaon experiments in a general theoretical context, and indicate how they may bear upon fundamental theoretical issues. A survey of different experiments which would be done with an Intense Medium Energy Source of Strangeness, including rare K decays, probes of the nature of CP isolation, μ decays, hyperon decays and neutrino physics is given
Theoretical perspectives on strange physics
Ellis, J.
1983-04-01
Kaons are heavy enough to have an interesting range of decay modes available to them, and light enough to be produced in sufficient numbers to explore rare modes with satisfying statistics. Kaons and their decays have provided at least two major breakthroughs in our knowledge of fundamental physics. They have revealed to us CP violation, and their lack of flavor-changing neutral interactions warned us to expect charm. In addition, K/sup 0/-anti K/sup 0/ mixing has provided us with one of our most elegant and sensitive laboratories for testing quantum mechanics. There is every reason to expect that future generations of kaon experiments with intense sources would add further to our knowledge of fundamental physics. This talk attempts to set future kaon experiments in a general theoretical context, and indicate how they may bear upon fundamental theoretical issues. A survey of different experiments which would be done with an Intense Medium Energy Source of Strangeness, including rare K decays, probes of the nature of CP isolation, ..mu.. decays, hyperon decays and neutrino physics is given. (WHK)
Strange decays of nonstrange baryons
The strong decays of excited nonstrange baryons into the final states ΛK, ΣK, and for the first time into Λ(1405)K, Λ(1520)K, Σ(1385)K, ΛK*, and ΣK*, are examined in a relativized quark pair creation model. The wave functions and parameters of the model are fixed by previous calculations of Nπ and Nππ, etc., decays. The results show that it should be possible to discover several new negative parity excited baryons and confirm the discovery of several others by analyzing these final states in kaon production experiments. They also establish clear predictions for the relative strengths of certain states to decay to Λ(1405)K and Λ(1520)K, which can be tested to determine if a three-quark model of the Λ(1405)K is valid. The authors results compare favorably with the results of partial wave analyses of the limited existing data for the ΛK and ΣK channels. They do not find large ΣK decay amplitudes for a substantial group of predicted and weakly established negative-parity states, in contrast to the only previous work to consider decays of these states into the strange final states ΛK and ΣK
Baryon Resonance Analysis from SAID
Arndt, R A; Paris, M W; Strakovsky, I I; Workman, R L
2009-01-01
We discuss the analysis of data from piN elastic scattering and single pion photo- and electroproduction. The main focus is a study of low-lying non-strange baryon resonances. Here we concentrate on some difficulties associated with resonance identification, in particular the Roper and higher P11 states.
Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)
1995-09-01
Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.
Narrow baryonia with open hidden strangeness
A search for baryonia with open and hidden strangeness decaying into strange particles has been carried out in a neutron beam with a mean momentum of 40 GeV/c with the BIS-2 spectrometer at the Serpukhov accelerator. There is a strong indication of the existence of baryonia with negative (Ms) and positive (M-bars) strangeness, decaying respectively into Λp-bar + pions and Λ-barp + pions. The isotopic spin of the strange baryonia is ≥ 3/2. Their mean mass is (3060 ±5 (st.) ± 20 (syst.)) MeV/c2. There is an indication of the existence of narrow baryonium with hidden strangeness (Mφ), decaying into Λp-barK+(+π±), Λ-barpK-(+π±) and K0spp-barK±. The mean value of its mass is (3260 ±5 (st.) ±20 (syst.)) MeV/c2. The widths of the searched baryonia are (35 ± 5) MeV/c. The production cross-sections the baryonia in the kinematic region XF ≥0.2 and Pt ≤ 1 GeV/c, are (0.3 - 1.0) μb/per nucleon (90% C.L.). 33 refs.; 9 figs.; 4 tabs
Strange hadron production at low transverse momenta
Veres, Gábor I.; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Noell, A.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sawicki, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Teng, R.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wyslouch, B.; Zhang, J.
2004-01-01
Some of the latest results of the PHOBOS experiment from the \\sqrt{s_{NN}}= 200\\ GeV Au+Au data are discussed. Those relevant to strangeness production are emphasized. These observations relate to the nature of the matter created when heavy ions collide at the highest achieved energy. The invariant yields of strange and non-strange charged hadrons at very low transverse momentum have been measured, and used to differentiate between different dynamical scenarios. In the intermediate transverse momentum range, the measured ratios of strange and anti-strange kaons approach one, while the antibaryon to baryon ratio is still significantly less, independent of collision centrality and transverse momentum. At high transverse momenta, we find that central and peripheral Au+Au collisions produce similar numbers of charged hadrons per participant nucleon pair, rather than per binary nucleon-nucleon collision. Finally, we describe the upgrades of PHOBOS completed for the 2003 d+Au and p+p run, which extend the transverse momentum range over which particle identification is possible and, at the same time, implement a trigger system selective for high-pT particles.
Strangeness production in proton–proton and proton–nucleus collisions
Radhey Shyam
2006-04-01
We discuss the investigation of the strange meson production in proton-proton () and proton–nucleus () reactions within an effective Lagrangian model. The kaon production proceeds mainly via excitations of * (1650), * (1710), and * (1720) resonant intermediate nucleonic states, in the collision of two initial state nucleons. Therefore, the strangeness production is expected to provide information about the resonances lying at higher excitation energies. For beam energies very close to the kaon production threshold the hyperon–proton final state interaction effects are quite important. Thus, these studies provide a check on the models of hyperon–nucleon interactions. The in medium production of kaons shows strong sensitivity to the self-energies of the intermediate mesons.
Strange quark content of the nucleon and dark matter searches
Young, R. D.
2013-01-01
The strange quark scalar content plays an important role in both the description of nucleon structure and in the determination of dark matter direct detection cross sections. As a measure of the strange-quark contribution to the nucleon mass, the strange-quark sigma term (\\sigma_s) provides important insight into the nature of mass generation in QCD. The phenomenological determination of \\sigma_s exhibits a wide range of variation, with values suggesting that the strange quark contributes any...
From Super-Hyper nuclei to Strange Stars
Both theoretical investigations of and experimental searches for not only super-hypernuclei (or long lived hyperstrange multiquark droplets,strangelets , or strange quark matter) consisting of roughly equal numbers of up, down, and strange quarks, but also super-hypernuclear matter in bulk (or quark nuggetsor strange matter) (in the early Universe or inside neutron stars) and strange stars made of super-hypernuclear matter are reviewed and discussed in some detail
Thermal Photons From Magnetized Bare Strange Stars
Méndez, Enrique Moreno; Patiño, Leonardo; Ortega, Patricia
2013-01-01
A plasma made out of strange-quark matter (SQM) and electrons, has a rather high plasma frequency (>20 MeV). Thus, a compact star made of such material all the way up to its surface, i.e., a bare strange star, would be unable to radiate away its thermal emission. We use the MIT-bag model and assume that SQM is the ground state of nuclear matter at high density. We investigate whether the presence of a magnetic field will allow propagation of radiation at frequencies below the SQM plasma frequencies. Hence, we study the presence of gyrofrequencies in a SQM plasma permeated by a strong magnetic field (B > 10^{12} G). We find that small regions in the frequency spectrum allow radiation propagation due to the presence of the magnetic fields. It is likely that narrow bands of radiation would likely be observable from magnetized bare strange stars .
A new deterministic model of strange stars
The observed evidence for the existence of strange stars and the concomitant observed masses and radii are used to derive an interpolation formula for the mass as a function of the radial coordinate. The resulting general mass function becomes an effective model for a strange star. The analysis is based on the MIT bag model and yields the energy density, as well as the radial and transverse pressures. Using the interpolation function for the mass, it is shown that a mass-radius relation due to Buchdahl is satisfied in our model. We find the surface redshift (Z) corresponding to the compactness of the stars. Finally, from our results, we predict some characteristics of a strange star of radius 9.9 km. (orig.)
A new deterministic model of strange stars
Rahaman, Farook; Kuhfittig, P K F; Shit, G C; Rahman, Mosiur
2014-01-01
The observed evidence for the existence of strange stars and the concomitant observed masses and radii are used to derive an interpolation formula for the mass as a function of the radial coordinate. The resulting general mass function becomes an effective model for a strange star. The analysis is based on the MIT bag model and yields the energy density, as well as the radial and transverse pressures. Using the interpolation function for the mass, it is shown that a mass-radius relation due to Buchdahl is satisfied in our model. We find the surface redshift ($Z$) corresponding to the compactness of the stars. Finally, from our results, we predict some characteristics of a strange star of radius 9.9 km.
A new deterministic model of strange stars
Rahaman, Farook; Shit, G.C. [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Chakraborty, Koushik [Government Training College, Department of Physics, Hooghly, West Bengal (India); Kuhfittig, P.K.F. [Milwaukee School of Engineering, Department of Mathematics, Milwaukee, WI (United States); Rahman, Mosiur [Meghnad Saha Institute of Technology, Department of Mathematics, Kolkata (India)
2014-10-15
The observed evidence for the existence of strange stars and the concomitant observed masses and radii are used to derive an interpolation formula for the mass as a function of the radial coordinate. The resulting general mass function becomes an effective model for a strange star. The analysis is based on the MIT bag model and yields the energy density, as well as the radial and transverse pressures. Using the interpolation function for the mass, it is shown that a mass-radius relation due to Buchdahl is satisfied in our model. We find the surface redshift (Z) corresponding to the compactness of the stars. Finally, from our results, we predict some characteristics of a strange star of radius 9.9 km. (orig.)
Strangeness in the baryon ground states
Semke, A
2012-01-01
We compute the strangeness content of the baryon ground states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.
Strangeness production in pp-bar collision
We study strangeness production reactions in the framework of a Chiral Constituent Quark Model. The model includes the coupling with the SU(3) pseudoscalar meson octet due to the spontaneous chiral symmetry breaking. It also includes QCD perturbative effects through the coupling with the gluon field. In this way the two traditional mechanism of strangeness production, i.e., the kaon exchange and gluon annihilation, are introduce in the same framework. Two meson exchanges are parametrized through the exchange of scalar mesons, namely a sigma and a kappa exchange. The kappa exchange allows a better description of the polarization observables of the pp-bar →ΛΛ-bar production reaction. Other strangeness production reaction in the isospin 1 sector are also studied.
2008-01-01
In this paper, a series of C-terminal modified analogs of endomorphin-2 is investigated using ESI-FT-ICR-MS. Some b, y″, a, and internal ions are found in the CID spectra and slight mass differ- ences between the calculated and observed results are obtained. Moreover, if the C-terminal modified group is t-butyloxy, it can lose butene through McLafferty rearrangement. FT-ICR MS shows its power in peptide sequencing successfully helping us obtain the structure of peptide analogs.
Measurements of strangeness production in the STAR experiment at RHIC
Wilson, W.K. [Wayne State Univ., Detroit, MI (United States)
1995-07-15
Simulations of the ability of the STAR (Solenoidal Tracker at RHIC) detector to measure strangeness production in central Au+Au collisions at RHIC are presented. Emphasis is placed on the reconstruction of short lived particles using a high resolution inner tracker. The prospects for performing neutral kaon interferometry are discussed. Simulation results for measurements of strange and multi-strange baryons are presented.
Some analytical models of anisotropic strange stars
Murad, Mohammad Hassan
2016-01-01
Over the years of the concept of local isotropy has become a too stringent condition in modeling relativistic self-gravitating objects. Taking local anisotropy into consideration, in this work, some analytical models of relativistic anisotropic charged strange stars have been developed. The Einstein-Maxwell gravitational field equations have been solved with a particular form of one of the metric potentials. The radial pressure and the energy density have been assumed to follow the usual linear equation of state of strange quark matter, the MIT bag model.
A new deterministic model of strange stars
Rahaman, Farook; Chakraborty, Koushik; Kuhfittig, P. K. F.(Department of Mathematics, Milwaukee School of Engineering, 53202-3109, Milwaukee, WI, USA); Shit, G. C.; Rahman, Mosiur
2014-01-01
The observed evidence for the existence of strange stars and the concomitant observed masses and radii are used to derive an interpolation formula for the mass as a function of the radial coordinate. The resulting general mass function becomes an effective model for a strange star. The analysis is based on the MIT bag model and yields the energy density, as well as the radial and transverse pressures. Using the interpolation function for the mass, it is shown that a mass–radius relation due t...
Stability of realistic strange stars (RSS)
Bhowmick, S; Dey, M; Ray, S; Ray, R; Bhowmick, Siddhartha; Dey, Jishnu; Dey, Mira; Ray, Subharthi; Ray, Ranjan
2001-01-01
Strange stars (SS) calculated from a realistic equation of state (EOS) are very stable, for example under fast rotation but have a soft surface, on which ripples may occur when radiation is emitted close to it. We suggest this as a natural explanation of the fluctuations observed in the intensity profile of X-ray pulsars. In contrast, SS based on EOS derived from the bag models (Bag SS) are less stable against fast rotation and do not have a hard surface and cannot explain these ripples. There are other important differences between Bag SS and the SS, based on a realistic EOS, which we call realistic strange stars (RSS).
KN Scattering and the Nucleon Strangeness Radius
Ramsey-Musolf, M. J.; Hammer, H. -W.
1997-01-01
The leading non-zero electric moment of the nucleon strange-quark vector current is the mean square strangeness radius, $$. We evaluate the lightest OZI-allowed contribution to $$, arising from the kaon cloud, using dispersion relations. Drawing upon unitarity constraints as well as $K^{+}N$ scattering and $e^+e^-\\to K\\bar{K}$ cross section data, we find the structure of this contribution differs significantly from that suggested by a variety of QCD-inspired model calculations. In particular,...
Strangeness Suppression in Proton-Proton Collisions
Drescher, Hans-Joachim; Aichelin, Joerg; Werner, Klaus
2001-01-01
We analyse strangeness production in proton-proton (pp) collisions at SPS and RHIC energies, using the recently advanced NeXus approach. After having verified that the model reproduces well the existing data, we interpret the results: strangeness is suppressed in proton-proton collisions at SPS energy as compared to electron-positron (e+e-) annihilation due to the limited masses of the strings produced in the reaction, whereas high energy pp and e+e- collisions agree quantitatively . Thus str...
TWO SUPER-EARTHS ORBITING THE SOLAR ANALOG HD 41248 ON THE EDGE OF A 7:5 MEAN MOTION RESONANCE
Jenkins, J. S. [Departamento de Astronomia, Universidad de Chile, Camino el Observatorio 1515, Las Condes, Santiago, Casilla 36-D (Chile); Tuomi, M. [Center for Astrophysics, University of Hertfordshire, College Lane Campus, Hatfield, Hertfordshire, AL10 9AB (United Kingdom); Brasser, R. [Institute for Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Ivanyuk, O. [Main Astronomical Observatory of National Academy of Sciences of Ukraine, 27 Zabolotnoho, Kyiv 127 03680 (Ukraine); Murgas, F., E-mail: jjenkins@das.uchile.cl [Instituto de Astrofisica de Canarias, Via Lactea, E-38205 La Laguna, Tenerife (Spain)
2013-07-01
There are a growing number of multi-planet systems known to be orbiting their host stars with orbital periods that place them in mean motion resonances (MMRs). These systems are generally in first-order resonances and dynamical studies have focused their efforts on understanding the origin and evolution of such dynamically resonant commensurabilities. Here we report the discovery of two super-Earths that are close to a second-order dynamical resonance orbiting the metal-poor ([Fe/H] = -0.43 dex) and inactive G2V star HD 41428. We analyzed 62 HARPS archival radial velocities for this star that, until now, exhibited no evidence for planetary companions. Using our new Bayesian Doppler signal detection algorithm, we find two significant signals in the data, with periods of 18.357 days and 25.648 days, indicating they could be part of a 7:5 second-order MMR. Both semi-amplitudes are below 3 m s{sup -1} and the minimum masses of the pair are 12.3 and 8.6 M{sub Circled-Plus }, respectively. Our simulations found that apsidal alignment stabilizes the system, and even though libration of the resonant angles was not seen, the system is affected by the presence of the resonance and could still occupy the 7:5 commensurability, which would be the first planetary configuration in such a dynamical resonance. Given the multitude of low-mass multi-planet systems that will be discovered in the coming years, we expect that more of these second-order resonant configurations will emerge from the data, highlighting the need for a better understanding of the dynamical interactions between forming planetesimals.
The Evolution of Proto-Strange Stars
Benvenuto, Omar G
2013-01-01
We perform 1D calculations of neutrino opacities inside a young "strange star" assumed to be the result of the conversion process of a normal neutron object. We evaluate the deleptonization and cooling timescales, which happen to be longer than the proto-NS analogues, and preliminary address the features of the emerging neutrino signal.
Seismic Search for Strange Quark Matter
Teplitz, Vigdor
2004-01-01
Two decades ago, Witten suggested that the ground state of matter might be material of nuclear density made from up, down and strange quarks. Since then, much effort has gone into exploring astrophysical and other implications of this possibility. For example, neutron stars would almost certainly be strange quark stars; dark matter might be strange quark matter. Searches for stable strange quark matter have been made in various mass ranges, with negative, but not conclusive results. Recently, we [D. Anderson, E. Herrin, V. Teplitz, and I. Tibuleac, Bull. Seis. Soc. of Am. 93, 2363 (2003)] reported a positive result for passage through the Earth of a multi-ton "nugget" of nuclear density in a search of about a million seismic reports, to the U.S. Geological Survey for the years 1990-93, not associated with known Earthquakes. I will present the evidence (timing of first signals to the 9 stations involved, first signal directions, and unique waveform characteristics) for our conclusion and discuss potential improvements that could be obtained from exploiting the seismologically quieter environments of the moon and Mars.
On pp → pKΛ, NKΣ, ppϕ — the basic ingredients for strangeness production in heavy ion collisions
The strangeness production in heavy ion collisions was proposed to be probes of the nuclear equation of state, Kaon potential in nuclear medium, strange quark matter and quark-gluon plasma, etc. However, to act as reliable probes, proper understanding of the basic ingredients for the strangeness production, such as pp → pK+Λ, pp → ppϕ and pp → nK+Σ+ is necessary. Recent study of these reactions clearly shows that previously ignored contributions from the spin-parity 1/2- resonances, N*(1535) and Δ*(1620), are in fact very important for these reactions, especially for near-threshold energies. It is necessary to include these contributions for getting reliable calculation for the strangeness production in heavy ion collisions. (author)
Ds1∗(2860) and Ds3∗(2860): candidates for 1D charmed-strange mesons
Newly observed two charmed-strange resonances, Ds1∗(2860) and Ds3∗(2860), are investigated by calculating their Okubo–Zweig–Iizuka-allowed strong decays, which shows that they are suitable candidates for the 13D1 and 13D3 states in the charmed-strange meson family. Our study also predicts other main decay modes of Ds1∗(2860) and Ds3∗(2860), which can be accessible at the future experiment. In addition, the decay behaviors of the spin partners of Ds1∗(2860) and Ds3∗(2860), i.e., 1D(2-) and 1D′(2-), are predicted in this work, which are still missing at present. The experimental search for the missing 1D(2-) and 1D′(2-) charmed-strange mesons is an intriguing and challenging task for further experiments
The strangeness content of the nucleon from effective field theory and phenomenology
We revisit the classical relation between the strangeness content of the nucleon, the pion–nucleon sigma term and the SU(3)F breaking of the baryon masses in the context of Lorentz covariant chiral perturbation theory with explicit decuplet-baryon resonance fields. We find that a value of the pion–nucleon sigma term of ∼60 MeV is not necessarily at odds with a small strangeness content of the nucleon, in line with the fulfillment of the OZI rule. Moreover, this value is indeed favored by our next-to-leading order calculation. We compare our results with earlier ones and discuss the convergence of the chiral series as well as the uncertainties of chiral approaches to the determination of the sigma terms.
Strangeness production in ultra-relativistic heavy-ion collisions: Flavour kinetics. Pt. 2
A recently presented model for the non-equilibrium expansion and hadronization of and the strangeness production in a quark-gluon plasma is developed further. The model includes all members of the lowest flavour SU(3) multiplets, the effect of particle evaporation from the surface of the system and a hydrodynamic treatment of the volume expansion. The evaporation and the decay of resonances are found to be equally important for the production of pions and kaons, and to give about 60% of the total yield. If a quark-gluon plasma is formed, the relative strangeness yield is strongly enhanced compared to pp collisions. The predictions of the model are also compared to recent data for nucleus-nucleus collisions. (orig.)
The associated strangeness production in pp collisions was studied at bombarding energies of 2.3 and 2.7 GeV by detecting the outgoing K+ particles with a high resolution magnetic spectrometer at forward angles up to 23.5 laboratory angle. The kaons were separated from an immense background of protons and pions by a highly resolving TOF electronics in addition to vetoes from Cerenkov detectors utilizing either β differing Cerenkov light cones in lucite or different thresholds for light production in aerogel. The hyperon-nucleon missing mass spectra obtained show strong deviations from pure phase space which is ascribed to final state interactions of the pΛ and the NΣ systems. The structures found are discussed and compared with results from K-d → π-YN experiments, with theoretical calculations in the frame of OBE models, and with the prediction of sharp strange dibaryon resonances from several quark-bag models. (orig.)
Scalar resonances as two-quark states
On the base of the theory with U(3)xU(3) symmetric chiral Lagrangian the properties of the two-quark scalar mesons are considered. It is shown, that the scalar resonances delta (980) and K(1240) may be treated as the p-wave states of anti qq system. The properties of the isovector and strange scalar mesons, obtained as a propetrties of the two-quark states, turn out to be very close to the properties of the isovector scalar resonance delta (980) and strange resonance K(1240)
On relativistic models of strange stars
Ramesh Tikekar; Kanti Jotania
2007-03-01
The superdense stars with mass-to-size ratio exceeding 0.3 are expected to be made of strange matter. Assuming that the 3-space of the interior space-time of a strange star is that of a three-paraboloid immersed in a four-dimensional Euclidean space, we obtain a two-parameter family of their physically viable relativistic models. This ansatz determines density distribution of the interior self-gravitating matter up to one unknown parameter. The Einstein's field equations determine the fluid pressure and the remaining geometrical variables. The information about mass-to-size ratio together with the conventional boundary conditions lead to the determination of total mass, radius and other parameters of the stellar configuration.
Strange attractor simulated on a quantum computer
Terraneo, M; Shepelyansky, D L
2003-01-01
Starting from the work of Lorenz, it has been realized that the dynamics of many various dissipative systems converges to so-called strange attractors. These objects are characterized by fractal dimensions and chaotic unstable dynamics of individual trajectories. They appear in nature in very different contexts, including applications to turbulence and weather forecast, molecular dynamics, chaotic chemical reactions, multimode solid state lasers and complex dynamics in ecological systems and physiology. The efficient numerical simulation of such dissipative systems can therefore lead to many important practical applications. Here we study a simple deterministic model where dynamics converges to a strange attractor, and show that it can be efficiently simulated on a quantum computer. Even if the dynamics on the attractor is unstable, dissipative and irreversible, a realistic quantum computer can simulate it in a reversible way, and, already with 70 qubits, will provide access to new informations unaccessible f...
A plethora of strange nonchaotic attractors
Surendra Singh Negi; Ramakrishna Ramaswamy
2001-01-01
We show that it is possible to devise a large class of skew-product dynamical systems which have strange nonchaotic attractors (SNAs): the dynamics is asymptotically on fractal attractors and the largest Lyapunov exponent is non-positive. Furthermore, we show that quasiperiodic forcing, which has been a hallmark of essentially all hitherto known examples of such dynamics is not necessary for the creation of SNAs.
Kaon condensation and multi-strange matter
Gazda, Daniel; Friedman, E.; Gal, A.; Mareš, Jiří
2010-01-01
Roč. 835, 1-4 (2010), s. 287-294. ISSN 0375-9474. [10th International Conference on Hypernuclear and Strange Particle Physics. Tokai, 14.09.2009-18.09.2009] Institutional research plan: CEZ:AV0Z10480505 Keywords : K)over-bar deeply bound nuclear states * multi-(K)over-bar nuclei * kaon condensation Subject RIV: BE - Theoretical Physics Impact factor: 1.986, year: 2010
From black holes to strange metals
Faulkner, Thomas; Iqbal, Nabil; Liu, Hong; McGreevy, John; Vegh, David
2010-01-01
Since the mid-eighties there has been an accumulation of metallic materials whose thermodynamic and transport properties differ significantly from those predicted by Fermi liquid theory. Examples of these so-called non-Fermi liquids include the strange metal phase of high transition temperature cuprates, and heavy fermion systems near a quantum phase transition. We report on a class of non-Fermi liquids discovered using gauge/gravity duality. The low energy behavior of these non-Fermi liquids...
Recent searchs for S = -1 strange dibaryons
A new p-p → K+X experiment has been performed at the Saturn National Laboratory to study through final state interaction λ-p and σ-N in a large range of momentum transfer and missing mass. After some recalls on recent searches on strange dibaryons we present here preliminary calculations of the p-p → K+ (λ)p differential cross section done within the one kaon exchange mechanism with (λ)-p final state interaction
Search for nuclei containing two strange quarks
This paper discusses a search for nuclei containing two strange quarks performed at Brookhaven National Laboratory. The goals and approach of experiment E885 are reviewed. Preliminary missing mass spectra for a subset of the data are presented, showing sensitivity for Ξ hypernuclei and H particle searches. Existence of an angular correlation between pions in the sequential decay of ΛΛ hypernuclei is suggested on theoretical grounds
Generic strange duality for $K3$ surfaces
Marian, Alina; Oprea, Dragos
2013-01-01
Strange duality is shown to hold over generic $K3$ surfaces in a large number of cases. The isomorphism for elliptic $K3$ surfaces is established first via Fourier–Mukai techniques. Applications to Brill–Noether theory for sheaves on $K3$ surfaces are also obtained. The appendix, written by Kota Yoshioka, discusses the behavior of the moduli spaces under change of polarization, as needed in the argument.
Some Aspects of Strange Matter in Astrophysics
Banerjee, Shibaji
2014-01-01
The present work is connected with the investigation of the origin and properties of compact astrophysical objects endowed with strangeness, with the objective of finding out their relevance in the formation and evolution of the universe. In the first part of the thesis, Chap.~1-3, we discuss a model, proposed by us, to describe the propagation of small lumps of Strange Quark Matter (SQM) or strangelets, through the Terrestrial atmosphere. The theoretical results were found to be well correlated with exotic cosmic ray events characterized by very low charge to mass ratio. In the next part, we have investigated the other end of the mass spectrum of SQM. In Chap 5, we have developed an analytical expression for the Chandrasekhar Limit of Strange Quark Stars. The limit is found to depend on the fundamental constants (including the bag constant). In the last chapter we have endeavored to show that the quark nuggets, surviving the quark-hadron phase transition in the millisecond era of the early Universe can provi...
Obach, R Scott; Walker, Gregory S; Brodney, Michael A
2016-05-01
Replacement of hydrogen with fluorine is a useful drug design strategy when decreases in cytochrome P450 (P450) metabolic lability are needed. In this paper, a facile two-step method of inserting fluorine into metabolically labile sites of drug molecules is described that utilizes less than 1 mg of starting material and quantitative NMR spectroscopy to ascertain the structures and concentrations of products. In the first step, hydroxyl metabolites are biosynthesized using human P450 enzymes, and in the second step these metabolites are subjected to deoxyfluorination using diethylaminosulfur trifluoride (DAST). The method is demonstrated using midazolam, celecoxib, ramelteon, and risperidone as examples and CYP3A5, 2C9, 1A2, and 2D6 to catalyze the hydroxylations. The drugs and their fluoro analogs were tested for metabolic lability. 9-Fluororisperidone and 4'-fluorocelecoxib were 16 and 4 times more metabolically stable than risperidone and celecoxib, respectively, and 2-fluororamelteon and ramelteon were metabolized at the same rate. 1'-Fluoromidazolam was metabolized at the same rate as midazolam by CYP3A4 but was more stable in CYP3A5 incubations. The P450-catalyzed sites of metabolism of the fluorine-containing analogs were determined. Some of the metabolites arose via metabolism at the fluorine-substituted carbon, wherein the fluorine was lost to yield aldehydes. In summary, this method offers an approach whereby fluorine can be substituted in metabolically labile sites, and the products can be tested to determine whether an enhancement in metabolic stability was obtained. PMID:26921388
Constraints on the Existence of Strange Quark Stars
Balberg, Shmuel
1997-01-01
Creation of strange quark stars through strong interaction deconfinement is studied based on modern estimates of hyperon formation in neutron stars. The hyperon abundance is shown to be large enough so that if strange quark matter (SQM) is the true ground state of matter, the deconfinement density should be at most 2.5-3 times the nuclear saturation density. If so, deconfinement occurs in neutron stars at birth, and all neutron stars must be strange quark stars. Alternatively, sould observati...
Strangeness asymmetry of the nucleon in the statistical parton model
Bourrely, Claude; Soffer, Jacques; Buccella, Franco
2007-04-01
We extend to the strange quarks and antiquarks, the statistical approach of parton distributions and we calculate the strange quark asymmetry s -sbar. We find that the asymmetry is small, positive in the low x region and negative in the high x region. In this framework, the polarized strange quarks and antiquarks distributions, which are obtained simultaneously, are found to be both negative for all x values.
Strangeness asymmetry of the nucleon in the statistical parton model
Bourrely, Claude [Centre de Physique Theorique, UMR 6207, Unite Mixte de Recherche du CNRS et des Universites Aix-Marseille I et Aix-Marseille II et de l' Universite du Sud Toulon-Var, Laboratoire affilie a la FRUMAM, CNRS-Luminy, Case 907, 13288 Marseille Cedex 9 (France); Soffer, Jacques [Le Zenon (A) Ave Campagne Berger, 13009 Marseille (France)]. E-mail: jacques.soffer@gmail.com; Buccella, Franco [Dipartimento di Scienze Fisiche, Universita di Napoli, Via Cintia, I-80126, Naples (Italy) and INFN, Sezione di Naples (Italy)
2007-04-26
We extend to the strange quarks and antiquarks, the statistical approach of parton distributions and we calculate the strange quark asymmetry s-s-bar. We find that the asymmetry is small, positive in the low x region and negative in the high x region. In this framework, the polarized strange quarks and antiquarks distributions, which are obtained simultaneously, are found to be both negative for all x values.
Strangeness asymmetry of the nucleon in the statistical parton model
Bourrely, Claude; Soffer, Jacques; Buccella, Franco
2007-01-01
We extend to the strange quarks and antiquarks, the statistical approach of parton distributions and we calculate the strange quark asymmetry $s-\\bar s$. We find that the asymmetry is small, positive in the low $x$ region and negative in the high $x$ region. In this framework, the polarized strange quarks and antiquarks distributions, which are obtained simultaneously, are found to be both negative for all $x$ values.
Strangeness asymmetry of the nucleon in the statistical parton model
We extend to the strange quarks and antiquarks, the statistical approach of parton distributions and we calculate the strange quark asymmetry s-s-bar. We find that the asymmetry is small, positive in the low x region and negative in the high x region. In this framework, the polarized strange quarks and antiquarks distributions, which are obtained simultaneously, are found to be both negative for all x values
The invention relates to devices for modelling the space-dependent kinetics of a nuclear reactor. It can be advantageously used in studying the dynamics of the neutron field in the core to determine the effect of the control rods on the power distribution in the core, for training purposes. The proposed analog model of a nuclear reactor comprises operational amplifiers and a grid of resistors simulating neutron diffusion. Connected to the grid nodes are supply resistors modelling absorption and multiplication of neutrons. This is achieved by that, in the proposed model, all resistors through which power is supplied to the grid nodes are interconnected by their other leads and coupled to the output of the amplifier unit common for all nodes. Therewith, the amlifier unit models the transfer function of a ''point'' reactor. Connected to the input of this unit which includes two to four amplifiers are resistors for addition of signals with a grid node. Coupled to the grid nodes via additional resistors are voltage sources simulating reactivity
Space-Time Geometry of Quark and Strange Quark Matter
无
2007-01-01
We study quark and strange quark matter in the context of general relativity. For this purpose, we solve Einstein's field equations for quark and strange quark matter in spherical symmetric space-times. We analyze strange quark matter for the different equations of state (EOS) in the spherical symmetric space-times, thus we are able to obtain the space-time geometries of quark and strange quark matter. Also, we discuss die features of the obtained solutions. The obtained solutions are consistent with the results of Brookhaven Laboratory, i.e. the quark-gluon plasma has a vanishing shear (i.e. quark-gluon plasma is perfect).
Is SAX J1808.4-3658 A Strange Star?
Li, X D; Dey, M; Dey, J; Van den Heuvel, E P J; Dey, Mira; Dey, Jishnu
1999-01-01
One of the most important questions in the study of compact objects is the nature of pulsars, including whether they are composed of $\\beta$-stable nuclear matter or strange quark matter. Observations of the newly discovered millisecond X-ray pulsar \\sax with the Rossi X-Ray Timing Explorer place firm constraint on the radius of the compact star. Comparing the mass - radius relation of \\sax with the theoretical mass - radius relation for neutron stars and for strange stars, we find that a strange star model is more consistent with \\sax, and suggest that it is a likely strange star candidate.
Tavousi, Alireza; Mansouri-Birjandi, Mohammad Ali; Saffari, Mehdi
2016-09-01
Implementing of photonic sampling and quantizing analog-to-digital converters (ADCs) enable us to extract a single binary word from optical signals without need for extra electronic assisting parts. This would enormously increase the sampling and quantizing time as well as decreasing the consumed power. To this end, based on the concept of successive approximation method, a 4-bit full-optical ADC that operates using the intensity-dependent Kerr-like nonlinearity in a two dimensional photonic crystal (2DPhC) platform is proposed. The Silicon (Si) nanocrystal is chosen because of the suitable nonlinear material characteristic. An optical limiter is used for the clamping and quantization of each successive levels that represent the ADC bits. In the proposal, an energy efficient optical ADC circuit is implemented by controlling the system parameters such as ring-to-waveguide coupling coefficients, the ring's nonlinear refractive index, and the ring's length. The performance of the ADC structure is verified by the simulation using finite difference time domain (FDTD) method.
Charm-strange baryon strong decays in a chiral quark model
Liu, Lei-Hua; Zhong, Xian-Hui
2012-01-01
The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, $\\Xi_c^*(2645)$, $\\Xi_c(2790)$ and $\\Xi_c(2815)$, are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons $\\Xi_c(2930)$, $\\Xi_c(2980)$, $\\Xi_c(3055)$, $\\Xi_c(3080)$ and $\\Xi_c(3123)$. Our predictions are given as follows. (i) $\\Xi_c(2930)$ might be the first $P$-wave excitation of $\\Xi_c'$ with $J^P=1/2^-$, favors the $|\\Xi_c'\\ ^2P_\\lambda 1/2^->$ or $|\\Xi_c'\\ ^4P_\\lambda 1/2^->$ state. (ii) $\\Xi_c(2980)$ might correspond to two overlapping $P$-wave states $|\\Xi_c'\\ ^2P_\\rho 1/2^->$ and $|\\Xi_c'\\ ^2P_\\rho 3/2^->$, respectively. The $\\Xi_c(2980)$ observed in the $\\Lambda_c^+\\bar{K}\\pi$ final state is most likely to be the $|\\Xi_c'\\ ^2P_\\rho 1/2^->$ state, while the narrower resonance with a mass $m\\simeq 2.97$ GeV observed in the $\\Xi_c^*(2645...
Strange and non-strange sea quark–gluon effects in nucleons
Batra, M.; Upadhyay, A.
2014-02-15
Within a statistical approach, strange and non-strange quark–gluon Fock state contributions are analyzed for their low energy properties. A suitable wave function is written for a nucleon that consists of three valence quarks (qqq) and the sea (g,qq{sup ¯}). Expansion of the nucleonic system in terms of Fock states that contain (g,qq{sup ¯}) is assumed and the probabilities of all possible Fock states, that lead to such a wave-function containing strange and non-strange quark–gluon contents in the sea are determined. Various approximations are entertained to validate the authenticity of the model used. The statistically determined coefficients strongly favor a vector-dominated sea where the sea includes ss{sup ¯} pairs. Additionally, the sea is constrained to have a limited number of components. The phenomenological implications that affect the low energy properties are discussed. The obtained results are compared to existing theoretical models and experimental data. -- Highlights: • A general expression to determine probabilities for each quark–gluon Fock states. • To calculate probabilities in flavor, spin and color space in statistical framework. • To analyze the sea-content and examine the contribution to various properties.
Strangeness and quark gluon plasma: Aspects of theory and experiment
A survey of our current understanding of the strange particle signature of quark gluon plasma is presented. Emphasis is placed on the theory of strangeness production in the plasma and recent pertinent experimental results. Useful results on spectra of thermal particles are given. (orig.)
Examination of the strangeness contribution to the nucleon magnetic moment
Chen, XS; Timmermans, RGE; Sun, WM; Zong, HS; Wang, F
2004-01-01
We examine the nucleon strangeness magnetic moment mu(s) with a lowest order meson cloud model. We observe that (1) strangeness in the nucleon is a natural requirement of the empirical relation mu(p)/mu(n)similar or equal to-3/2, which favors an SU(3) octet meson cloud instead of merely the SU(2) pi
Collider phenomenology of light strange-beauty squarks
We summarize a study on the production, decay, and detection of the strange-beauty squark as light as 200 GeV at hadronic and e+e- colliders. It was motivated by nearly maximal mixing between strange and beauty squarks. (author)
Mini-Proceedings of ECT Workshop "Strangeness in Nuclei"
Curceanu, C
2011-01-01
This workshop brought together international experts in the research area of strangeness in nuclei physics, working on theory as well as on experiments, to discuss the present status, to develop new methods of analysis and to have the opportunity for brainstorming towards future studies, going towards a deeper understanding of the hot topics in the low-energy QCD in the strangeness sector.
Night Academy: Heroines, Hunters and Strange Vampires
Sólveig Geirsdóttir 1988
2013-01-01
It was within the Gothic genre that the literary vampire derived. The literary vampire has gained new popularity in the last decade with a new formula focusing on sympathetic vampires. This essay examines four contemporary vampire literary series that have all included a special vampire school. The four series analyzed in this essay are House of Night by P.C. and Kristin Cast, Strange Angels by Lili St. Crow, Vampire Academy by Richelle Mead and Vamps by Nancy A. Collins. The essay determines...
Strange Particle Production Via The Weak Interaction
Adera, G B; van Niekerk, D D; Mart, T; 10.1103/PhysRevC.82.025501
2011-01-01
The differential cross sections for the neutrino-induced weak charged current production of strange particles in the threshold energy region are presented. The general representation of the weak hadronic current is newly developed in terms of eighteen unknown invariant amplitudes to parametrize the hadron vertex. The Born term approximation is used for the numerical calculations in the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet baryons four processes are investigated, whereas in the case of polarized baryons only one process is chosen to study the sensitivity of the differential cross section to the various polarizations of the initial state nucleon and the final state hyperon.
STRANGE BARYONIC MATTER AND KAON CONDENSATION
Gazda, Daniel; Friedman, E.; Gal, A.; Mareš, Jiří
2011-01-01
Roč. 26, 3-4 (2011), s. 567-569. ISSN 0217-751X. [11th International Workshop on Meson Production, Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/09/1441 Institutional research plan: CEZ:AV0Z10480505 Keywords : (K)over-bar-nuclear bound states * strange baryonic matter * kaon condensation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.053, year: 2011
METHODOLOGICAL NOTES: Strange attractors in rattleback dynamics
Borisov, Aleksei V.; Mamaev, Ivan S.
2003-04-01
This review is dedicated to the dynamics of the rattleback, a phenomenon with curious physical properties that is studied in nonholonomic mechanics. All known analytical results are collected here, and some results of our numerical simulation are presented. In particular, three-dimensional Poincare maps associated with dynamical systems are systematically investigated for the first time. It is shown that the loss of stability of periodic and quasiperiodic solutions, which gives rise to strange attractors, is typical of the three-dimensional maps related to rattleback dynamics. This explains some newly discovered properties of the rattleback related to the transition from regular to chaotic solutions at certain values of the physical parameters.
Strange Curves, Counting Rabbits, & Other Mathematical Explorations
Ball, Keith
2011-01-01
How does mathematics enable us to send pictures from space back to Earth? Where does the bell-shaped curve come from? Why do you need only 23 people in a room for a 50/50 chance of two of them sharing the same birthday? In Strange Curves, Counting Rabbits, and Other Mathematical Explorations, Keith Ball highlights how ideas, mostly from pure math, can answer these questions and many more. Drawing on areas of mathematics from probability theory, number theory, and geometry, he explores a wide range of concepts, some more light-hearted, others central to the development of the field and used dai
Strange Quark Matter Status and Prospects
Sandweiss, J.
2004-01-01
The existence of quark states with more than three quarks is allowed in QCD. The stability of such quark matter states has been studied with lattice QCD and phenomenological bag models, but is not well constrained by theory. The addition of strange quarks to the system allows the quarks to be in lower energy states despite the additional mass penalty. There is additional stability from reduced Coulomb repulsion. SQM is expected to have a low Z/A. Stable or metastable massive multiquark states contain u, d, and s quarks.
Stability of charged strange quark stars
Arbañil, José D. V.; Malheiro, Manuel [Departamento de Física, Instituto Tecnológico de Aeronáutica, Centro Técnico Aeroespacial, 12228-900 São José dos Campos, SP (Brazil)
2015-12-17
We investigate the hydrostatic equilibrium and the stability of charged stars made of a charged perfect fluid. The matter contained in the star follows the MIT bag model equation of state and the charge distribution to a power-law of the radial coordinate. The hydrostatic equilibrium and the stability of charged strange stars are analyzed using the Tolman-Oppenheimer-Volkoff equation and the Chandrasekhar’s equation pulsation, respectively. These two equation are modified from their original form to the inclusion of the electric charge. We found that the stability of the star decreases with the increment of the central energy density and with the increment of the amount of charge.
Strangeness at high temperatures: from hadrons to quarks.
Bazavov, A; Ding, H-T; Hegde, P; Kaczmarek, O; Karsch, F; Laermann, E; Maezawa, Y; Mukherjee, Swagato; Ohno, H; Petreczky, P; Schmidt, C; Sharma, S; Soeldner, W; Wagner, M
2013-08-23
Appropriate combinations of up to fourth order cumulants of net strangeness fluctuations and their correlations with net baryon number and electric charge fluctuations, obtained from lattice QCD calculations, have been used to probe the strangeness carrying degrees of freedom at high temperatures. For temperatures up to the chiral crossover, separate contributions of strange mesons and baryons can be well described by an uncorrelated gas of hadrons. Such a description breaks down in the chiral crossover region, suggesting that the deconfinement of strangeness takes place at the chiral crossover. On the other hand, the strangeness carrying degrees of freedom inside the quark gluon plasma can be described by a weakly interacting gas of quarks only for temperatures larger than twice the chiral crossover temperature. In the intermediate temperature window, these observables show considerably richer structures, indicative of the strongly interacting nature of the quark gluon plasma. PMID:24010429
Rapidity dependence of strangeness enhancement factor at FAIR energies
Strange particles are produced only at the time of collisions and thus expected to carry important information of collision dynamics. Strangeness enhancement is considered to be one of the traditional signatures of formation of Quark Gluon Plasma (QGP). Due to the limitation of the detector acceptance, the past and ongoing heavy ion experiments could measure the strangeness enhancement at midrapidity only. But the future heavy ion experiment CBM at FAIR will have the access to the entire forward rapidity hemisphere and thus the experimental determination of rapidity dependent strangeness enhancement is a possibility. In this work, an attempt has therefore been made to study the rapidity dependent strangeness enhancement at FAIR energies with the help of a string based hadronic model (UrQMD). A sum of 93 million minimum biased UrQMD events have been used for the present analysis
Geng, J J; Lu, T
2015-01-01
Strange quark matter (SQM) may be the true ground state of hadronic matter, indicating that the observed pulsars may actually be strange stars, but not neutron stars. According to this SQM hypothesis, the existence of a hydrostatically stable sequence of strange quark matter stars has been predicted, ranging from 1 --- 2 solar mass strange stars, to smaller strange dwarfs and even strange planets. While gravitational wave (GW) astronomy is expected to open a new window to the universe, it will shed light on the searching for SQM stars. Here we show that due to their extreme compactness, strange planets can spiral very close to their host strange stars, without being tidally disrupted. Like inspiraling neutron stars or black holes, these systems would serve as a new kind of sources for GW bursts, producing strong gravitational waves at the final stage. The events occurring in our local Universe can be detected by the upcoming gravitational wave detectors, such as Advanced LIGO and the Einstein Telescope. This ...
K-p interactions at 11 GeV/c: new results on strange meson systems
The status of our programmatic study of states containing a strange quark is briefly reviewed. An 11 GeV/c K-p experiment run on the LASS spectrometer at SLAC is discussed and preliminary results presented for several inelastic channels based on approximately one half of the available data sample. In addition, new results utilizing the full statistics of the experiment are presented for the elastic K-π+ channel from the K-π+n final state. The well established leading K*(890), K*(1435), and K*(1780) resonances are observed, and clear evidence is presented for a new J/sup p/ = 4+ resonance at approx. 2070 MeV. Preliminary results from an energy independent partial wave analysis of these data are presented which display unambiguous evidence for resonant structure in the non-leading 0+ and 1- waves
Electromagnetic production of hyperon resonances
K. Hicks, D. Keller, W. Tang
2011-10-01
The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the {Lambda}(1405) resonance; a strong suggestion of meson cloud effects in the structure of the {Sigma}(1385) resonance; data from K* photoproduction that will test the existence of the purported K{sub 0}(800)$ meson. Properties of other hyperon resonances will also be studied in the near future.
Strange Matter: a state before black hole
Xu, Renxin
2016-01-01
Normal baryonic matter inside an evolved massive star can be intensely compressed by gravity after a supernova. General relativity predicts formation of a black hole if the core material is compressed into a singularity, but the real state of such compressed baryonic matter (CBM) before an event horizon of black hole appears is not yet well understood because of the non-perturbative nature of the fundamental strong interaction. Certainly, the rump left behind after a supernova explosion could manifest as a pulsar if its mass is less than the unknown maximum mass, $M_{\\rm max}$. It is conjectured that pulsar-like compact stars are made of strange matter (i.e., with 3-flavour symmetry), where quarks are still localized as in the case of nuclear matter. In principle, different manifestations of pulsar-like objects could be explained in the regime of this conjecture. Besides compact stars, strange matter could also be manifested in the form of cosmic rays and even dark matter.
Metastable strange matter and compact quark stars
Malheiro, M; Taurines, A R
2003-01-01
Strange quark matter in beta equilibrium at high densities is studied in a quark confinement model. Two equations of state are dynamically generated for the {\\it same} set of model parameters used to describe the nucleon: one corresponds to a chiral restored phase with almost massless quarks and the other to a chiral broken phase. The chiral symmetric phase saturates at around five times the nuclear matter density. Using the equation of state for this phase, compact bare quark stars are obtained with radii and masses in the ranges $R\\sim 5 - 8$ km and $M\\sim M_\\odot$. The energy per baryon number decreases very slowly from the center of the star to the periphery, remaining above the corresponding values for the iron or the nuclear matter, even at the edge. Our results point out that strange quark matter at very high densities may not be absolutely stable and the existence of an energy barrier between the two phases may prevent the compact quarks stars to decay to hybrid stars.
``Towards Strange Metallic Holography'
Hartnoll, Sean A.; /Harvard U., Phys. Dept. /Santa Barbara, KITP /UC, Santa Barbara; Polchinski, Joseph; Silverstein, Eva; /Santa Barbara, KITP /UC, Santa Barbara; Tong, David; /Cambridge U., DAMTP /Santa Barbara, KITP /UC, Santa Barbara
2010-08-26
We initiate a holographic model building approach to 'strange metallic' phenomenology. Our model couples a neutral Lifshitz-invariant quantum critical theory, dual to a bulk gravitational background, to a finite density of gapped probe charge carriers, dually described by D-branes. In the physical regime of temperature much lower than the charge density and gap, we exhibit anomalous scalings of the temperature and frequency dependent conductivity. Choosing the dynamical critical exponent z appropriately we can match the non-Fermi liquid scalings, such as linear resistivity, observed in strange metal regimes. As part of our investigation we outline three distinct string theory realizations of Lifshitz geometries: from F theory, from polarized branes, and from a gravitating charged Fermi gas. We also identify general features of renormalization group flow in Lifshitz theories, such as the appearance of relevant charge-charge interactions when z {ge} 2. We outline a program to extend this model building approach to other anomalous observables of interest such as the Hall conductivity.
Gaussian Anisotropy In Strange Quark Stars
Panahi, H; Eghdami, I
2015-01-01
In this paper for studying the anisotropic strange quark stars, we assume that the radial pressure inside the anisotropic star is a superposition of pressure in an isotropic case plus a Gaussian perturbation term. Considering a proportionality between electric charge density and the density of matter, we solve the TOV equation for different cases numerically. Our results indicate that anisotropy increases the maximum mass $M_{max}$ and also its corresponding radius $R$ for a typical strange quark star. According to our calculations, an anisotropy amplitude of $A=3\\times10^{33}Nm^{-2}$ with a standard deviation of $\\sigma=3\\times10^{3}m$ leads to a neutron star of 1.97$M_{\\odot}$. Furthermore, electric charge not only increases the maximum mass and its corresponding radius, but also raises up the anisotropy factor. We can see that the tangential pressure $p_{t}$ and anisotropy factor $\\Delta$ unlike the radial pressure $p_{r}$ have a maximum on the surface and this maximum increases by adding electric charge e...
Strangeness and Charm in Nuclear Matter
Tolos, Laura; Garcia-Recio, Carmen; Molina, Raquel; Nieves, Juan; Oset, Eulogio; Ramos, Angels; Romanets, Olena; Salcedo, Lorenzo Luis
2012-01-01
The properties of strange ($K$, $\\bar K$ and $\\bar K^*$) and open-charm ($D$, $\\bar D$ and $D^*$) mesons in dense matter are studied using a unitary approach in coupled channels for meson-baryon scattering. In the strangeness sector, the interaction with nucleons always comes through vector-meson exchange, which is evaluated by chiral and hidden gauge Lagrangians. For the interaction of charmed mesons with nucleons we extend the SU(3) Weinberg-Tomozawa Lagrangian to incorporate spin-flavor symmetry and implement a suitable flavor symmetry breaking. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects and meson self-energies. On one hand, we obtain the $K$, $\\bar K$ and $\\bar K^*$ spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also make an estimate of the transparency ratio of the $\\gamma A \\to K^+ K^{*-} A^\\prime$ reaction, which we propose as a tool to detect in-medium modifications of the $\\bar K^*$ meson....
Multibaryons with strangeness, charm and bottom
Kopeliovich, V.B. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Inst. Yadernykh Issledovanij; Durham Univ. (United Kingdom). Dept. of Mathematical Sciences; Zakrzewski, W.J. [Durham Univ. (United Kingdom). Dept. of Mathematical Sciences
2000-12-01
The spectra of baryonic systems with strangeness, charm and bottom are considered within a ''rigid oscillator'' version of the bound state soliton model. The static properties of multiskyrmions, of baryon number up to B=8, are calculated using the recently suggested rational map ansaetze as starting field configurations. The property of binding of flavoured mesons by an SU(2) skyrmion is proved rigorously within this model. Binding energy estimates are made of the states with largest isospin which can appear as negatively charged nuclear fragments and for states with zero isospin - fragments of ''flavoured'' nuclear matter. It is shown that for all types of flavour and for vertical stroke F vertical stroke {<=}2 the isoscalar baryonic systems have a better chance to be stable against strong and electromagnetic interactions than those with nonzero isospin. Baryonic systems with charm or bottom quantum numbers are found to be bound more than strange baryonic systems. (orig.)
Chen, Wai-Kai
2009-01-01
Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.
HERMES measurements of the strange parton distribution and strange quark helicity distribution
Kravchenko, Polina [PNPI, St. Petersburg (Russian Federation)
2009-07-01
The helicity density of the strange quark sea in the proton has been extracted from measurements of polarized semi-inclusive production of charged kaons in deep inelastic scattering of positrons from a polarized deuteron target. The isoscalar nature of the deuteron target (assuming isospin symmetry) and lack of isospin for strange quarks allows the deuteron target to be used independently without relying on fragmentation models or other experimental data. In the region of measurement of x>0.02 the helicity density is zero within experimental error and the measured first moment of the density is 0.006+/-0.029(stat)+/-0.007(sys)/. The first moment of the axial charge in the measured region is substantially less than that inferred from hyperon semi-leptonc decays.
Science Teachers' Analogical Reasoning
Mozzer, Nilmara Braga; Justi, Rosária
2013-08-01
Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.
Determining the strange quark mass for 2-flavour QCD
Using the O(a) Symanzik improved action an estimate is given for the strange quark mass for unquenched (nf=2) QCD. The determination is via the axial Ward identity (AWI) and includes a non-perturbative evaluation of the renormalisation constant. Numerical results have been obtained at several lattice spacings, enabling the continuum limit to be taken. Our results indicate a value for the strange quark mass (in the MS-bar -scheme at a scale of 2 GeV) in the range 100 - 130 MeV. A comparison is also made with other recent lattice determinations of the strange quark mass using dynamical sea quarks
Determining the strange quark mass for 2-flavour QCD
Using the O(a) Symanzik improved action an estimate is given for the strange quark mass for unquenched (nf=2) QCD. The determination is via the axial Ward identity (AWI) and includes a non-perturbative evaluation of the renormalisation constant. Numerical results have been obtained at several lattice spacings, enabling the continuum limit to be taken. Our results indicate a value for the strange quark mass (in the anti M anti S-scheme at a scale of 2 GeV) in the range 100 - 130 MeV. A comparison is also made with other recent lattice determinations of the strange quark mass using dynamical sea quarks. (orig.)
Probing Strange Stars with Advanced Gravitational Wave Detectors
Moraes, P. H. R. S.; Miranda, O. D.
2014-01-01
When a neutron star is compressed to huge densities, it may be converted to a strange star. In property of the event/year rate of a neutron star - strange star binary system, we show that the operational phase of advanced gravitational wave detectors may bring up some evidences that such strange stars do exist. Moreover we argue that such a system could be a plausible progenitor to GRB 051103 and GRB 070201, whose non-detection by LIGO last run awaits convincing explanation.
Evidence against a strange ground state for baryons
We argue that if strange quark matter were the ground state of baryons at zero pressure and if some observed compact stars (or some cosmic rays) are strange, then the interstellar medium is so contaminated by strangelets that essentially all 'neutron' stars in the disk of the galaxy could have to be quark stars: Strangelet contamination would apparently vastly exceed the minimum abundance needed to seed all newly born neutron stars. Because observed glitches seem not to be compatible with quark stars, a strange quark ground state is unlikely. (orig.)
16th International Conference on Strangeness in Quark Matter
2016-01-01
Topical conference on Strangeness and Heavy Flavor production in Heavy-Ion Collisions The conference will focus on new experimental and theoretical developments on the role of strange and heavy-flavour quarks in proton-proton and in heavy-ion collisions, and in astrophysical phenomena. New results are expected, from the LHC, from RHIC and from other experimental programs. The 16th International Conference on Strangeness in Quark Matter, follows the recent events of 2015 in Dubna, 2013 in Birmingham, and 2011 in Cracow.
Strange quark matter in a chiral SU(3) quark mean field model
Wang, P.; Lyubovitskij, V. E.; Gutsche, Th.; Faessler, Amand
2002-01-01
We apply the chiral SU(3) quark mean field model to investigate strange quark matter. The stability of strange quark matter with different strangeness fraction is studied. The interaction between quarks and vector mesons destabilizes the strange quark matter. If the strength of the vector coupling is the same as in hadronic matter, strangelets can not be formed. For the case of beta equilibrium, there is no strange quark matter which can be stable against hadron emission even without vector m...
Strange pathways for black hole formation
Immediately after they are born, neutron stars are characterized by an entropy per baryon of order unity and by the presence of trapped neutrinos. If the only hadrons in the star are nucleons, these effects slightly reduce the maximum mass relative to cold, catalyzed matter. However, if strangeness-bearing hyperons, a kaon condensate, or quarks are also present, these effects result in an increase in the maximum mass of up to ∼ 0.3M[odot] compared to that of a cold, neutrino-free star. This makes a sufficiently massive proto-neutron star metastable, so that after a delay of 10-100 seconds, the PNS collapses into a black hole. Such an event might be straightforward to observe as an abrupt cessation of neutrinos when the instability is triggered
Strange quark matter in explosive astrophysical systems
Sagert, I; Hempel, M; Pagliara, G; Schaffner-Bielich, J; Thielemann, F -K; Liebendörfer, M
2010-01-01
Explosive astrophysical systems, such as supernovae or compact star binary mergers, provide conditions where strange quark matter can appear. The high degree of isospin asymmetry and temperatures of several MeV in such systems may cause a transition to the quark phase already around saturation density. Observable signals from the appearance of quark matter can be predicted and studied in astrophysical simulations. As input in such simulations, an equation of state with an integrated quark matter phase transition for a large temperature, density and proton fraction range is required. Additionally, restrictions from heavy ion data and pulsar observation must be considered. In this work we present such an approach. We implement a quark matter phase transition in a hadronic equation of state widely used for astrophysical simulations and discuss its compatibility with heavy ion collisions and pulsar data. Furthermore, we review the recently studied implications of the QCD phase transition during the early post-bou...
Strange Attractor in Immunology of Tumor Growth
Voitikova, M
1997-01-01
The time delayed cytotoxic T-lymphocyte response on the tumor growth has been developed on the basis of discrete approximation (2-dimensional map). The growth kinetic has been described by logistic law with growth rate being the bifurcation parameter. Increase in the growth rate results in instability of the tumor state and causes period-doubling bifurcations in the immune+tumor system. For larger values of tumor growth rate a strange attractor has been observed. The model proposed is able to describe the metastable-state production when time series data of the immune state and the number of tumor cells are irregular and unpredictable. This metastatic disease may be caused not by exterior (medical) factors, but interior density dependent ones.
Strangeness photoproduction with the SAPHIR-detector
At the ELSA facility at Bonn a photon beam with a high duty cycle up to energies of 3.3 GeV is available. In this energy range the large solid angle detector SAPHIR enables us to investigate the strangeness photoproduction starting from threshold. SAPHIR has already achieved results for the reactions γ+p→K++Λ and γ+p→K++Σ0. This work investigates the possibilities to measure the related reactions γ+n→K0+Λ and γ+n→K0+Σ0 at a deuteron target and to measure the reaction γ+p→K0+Σ+ at a proton target. For the first time the Σ+ polarisation has been measured. With an cross section 10 times smaller compared to the kaon hyperon reactions, the photoproduction of the Φ(1020) meson can be investigated with the SAPHIR detector too. First reconstructed events are shown. (orig.)
The Universe is a Strange Place
Wilczek, F
2006-01-01
Our understanding of ordinary matter is remarkably accurate and complete, but it is based on principles that are very strange and unfamiliar. As I'll explain, we've come to understand matter to be a Music of the Void, in a remarkably literal sense. Just as we physicists finalized that wonderful understanding, towards the end of the twentieth century, astronomers gave us back our humility, by informing us that ordinary matter -- what we, and chemists and biologists, and astronomers themselves, have been studying all these centuries constitutes only about 5% of the mass of the universe as a whole. I'll describe some of our promising attempts to rise to this challenge by improving, rather than merely complicating, our description of the world.
Deb, Debabrata; Ray, Saibal; Rahaman, Farook
2015-01-01
In the present letter we attempt to find a new class of solutions relating radiation model by using Homotopy Perturbation Method (HPM). We consider that the spherical distribution is made of perfect fluid where radiation is along the radially outward direction of the system. Here we have employed HPM as a new tool for astrophysical systems which via the mass polynomial facilitates solving of field equations. A set of interior solutions has been found out on the basis of the equation of state in the form $p=\\frac{1}{3}\\rho$ with the demand that the radiation model is consistent with the Schwarzschild metric. It is observed that the set of solutions thus developed provides new metric to explain strange star which however seems not free from singularity.
Superconducting circuit probe for analog quantum simulators
Du, Liang-Hui; You, J. Q.; Tian, Lin
2015-07-01
Analog quantum simulators can be used to study quantum correlation in novel many-body systems by emulating the Hamiltonian of these systems. One essential question in quantum simulation is to probe the properties of an emulated many-body system. Here we present a circuit QED scheme for probing such properties by measuring the spectrum of a superconducting resonator coupled to a quantum simulator. We first study a general framework of this approach and show that the spectrum of the resonator is directly related to the correlation function of the coupling operator between the resonator and the simulator. We then apply this scheme to a simulator of the transverse field Ising model implemented with superconducting qubits, where the resonance peaks in the resonator spectrum correspond to the frequencies of the elementary excitations. The effects of resonator damping, qubit decoherence, and resonator backaction are also discussed. This setup can be used to probe a broad range of many-body models.
Intuitive analog circuit design
Thompson, Marc
2013-01-01
Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi
Integrating out strange quarks in ChPT: Terms at order p6
Chiral perturbation theory in the two-flavour sector allows one to analyse Green functions in QCD in a limit where the strange quark mass is considered to be large in comparison to the external momenta and to the light quark masses mu and md. In this framework, the low-energy constants of SU(2)RxSU(2)L depend on the value of the heavy quark masses. In a recent article, we have worked out, for the coupling constants li which occur at order p4 in the chiral expansion, the dependence on the strange quark mass at two-loop accuracy. Here, we provide analogous relations for some of the couplings ci which are relevant at order p6. To keep the calculations somewhat reasonable in size, we consider only those 28 couplings which enter the Green functions built from vector and axial vector quark currents in the chiral limit mu=md=0, ms≠0. This provides the matching for 27 linear combinations of the 28 couplings.
K meson-nucleus interactions: strangeness and nuclear matter
A brief review is provided of some straightforward K-nuclear and Λ-hypernuclear systems. A discussion of less straightforward speculations on H-dibaryons and strange quark matter by many authors, is also given. 28 refs., 6 figs
A Possible Resolution of the Strange Quark Polarization Puzzle ?
Leader, Elliot; Stamenov, Dimiter B
2011-01-01
We propose a possible resolution of the strange quark polarization puzzle i.e. of the contradiction between the negative polarized strange quark density obtained from analyses of inclusive DIS data and the positive values obtained from combined analyses of inclusive and semi-inclusive SIDIS data using de Florian et. al. (DSS) fragmentation functions. To this end the results of a new combined NLO QCD analysis of the polarized inclusive and semi-inclusive DIS data, using the Hirai et. al. (HKNS) fragmentation functions, are presented. It is demonstrated that the polarized strange quark density is very sensitive to the kaon fragmentation functions, and if the set of HKNS fragmentation functions is used, the polarized strange quark density from the combined analysis turns out to be negative and well consistent with values obtained from the pure DIS analyses.
Possible resolution of the strange quark polarization puzzle?
Leader, Elliot; Sidorov, Alexander V.; Stamenov, Dimiter B.
2011-07-01
The strange quark polarization puzzle, i.e. the contradiction between the negative polarized strange quark density obtained from analyses of inclusive deep inelastic scattering data and the positive values obtained from combined analyses of inclusive and semi-inclusive deep inelastic scattering data using de Florian, Sassot, Stratmann fragmentation functions, is discussed. To this end the results of a new combined next-to-leading order QCD analysis of the polarized inclusive and semi-inclusive deep inelastic scattering data, using the Hirai, Kumano, Nagai, Sudoh (HKNS) fragmentation functions, are presented. It is demonstrated that the polarized strange quark density is very sensitive to the kaon fragmentation functions, and if the set of HKNS fragmentation functions is used, the polarized strange quark density obtained from the combined analysis turns out to be negative and well consistent with values obtained from the pure deep inelastic scattering analyses.
Possible resolution of the strange quark polarization puzzle?
The strange quark polarization puzzle, i.e. the contradiction between the negative polarized strange quark density obtained from analyses of inclusive deep inelastic scattering data and the positive values obtained from combined analyses of inclusive and semi-inclusive deep inelastic scattering data using de Florian, Sassot, Stratmann fragmentation functions, is discussed. To this end the results of a new combined next-to-leading order QCD analysis of the polarized inclusive and semi-inclusive deep inelastic scattering data, using the Hirai, Kumano, Nagai, Sudoh (HKNS) fragmentation functions, are presented. It is demonstrated that the polarized strange quark density is very sensitive to the kaon fragmentation functions, and if the set of HKNS fragmentation functions is used, the polarized strange quark density obtained from the combined analysis turns out to be negative and well consistent with values obtained from the pure deep inelastic scattering analyses.
From strangelets to strange stars: A unified description
Xia, Cheng-Jun; Zhao, En-Guang; Zhou, Shan-Gui
2015-01-01
The conventionally separated treatments for strangelets and strange stars are now unified with a more comprehensive theoretical description for objects ranging from strangelets to strange stars. After constraining the model parameter according to the Witten-Bodmer hypothesis and observational mass-radius probability distribution of pulsars, we investigate the properties of this kind of objects. It is found that the energy per baryon decreases monotonously for increasing baryon number and reaches its minimum at the maximum baryon number, corresponding to the most massive strange star. Due to the quark depletion, an electric potential well for negatively charged particles is formed on the surface of the quark part, which may provide some unique observables. For a rotational bare strange star, a magnetic field with the typical strength of pulsars is generated.
Strange quark matter:Business as usual or phase transition?
Torrieri, Giorgio
2011-01-01
We give an overview of some results presented at the Strange Quark Matter 2011 conference in Krakow, and interpret them in light of the search of the search for a QCD deconfinement phase transition in heavy ion collisions
A relativistic mean field study of multi-strange system
In this paper, we study the binding energies, radii, single-particle energies, spin-orbit potential and density profile for multi-strange hypernuclei in the range of light mass to superheavy mass region within the relativistic mean field (RMF) theory. The stability of multi-strange hypernuclei as a function of introduced hyperons (Λ and Σ) is investigated. The neutron, lambda and sigma mean potentials are presented for light to superheavy hypernuclei. The inclusion of hyperons affects the nucleon, lambda and sigma spin-orbit potentials significantly. The bubble structure of nuclei and corresponding hypernuclei is studied. Nucleon and lambda halo structures are also investigated. A large class of bound multi-strange systems formed from the combination of nucleons and hyperons (n, p, Λ, Σ+ and n, p, Λ, Σ-) is suggested in the region of superheavy hypernuclei which might be stable against the strong decay. These multi-strange systems might be produced in heavy-ion reactions. (author)
Collider phenomenology of light strange-beauty squarks
Strong mixing between right-handed strange and beauty squarks is a possible solution to the CP violation discrepancy in B→φKS decay as recently suggested by the Belle data. In this scenario, thanks to the strong mixing one of the strange-beauty squarks can be as light as 200 GeV, even though the generic supersymmetry scale is at TeV. In this work, we study the production of this light right-handed strange-beauty squark at hadronic colliders and discuss the detection in various decay scenarios. Detection prospect at the Tevatron run II is good for the strange-beauty squark mass up to about 300 GeV
On the strange quark mass with improved staggered quarks
Hein, J.; Davies, C; Lepage, G. P.; Mason, Q.; Trottier, H.
2002-01-01
We present results on the sum of the masses of light and strange quark using improved staggered quarks. Our calculation uses 2+1 flavours of dynamical quarks. The effects of the dynamical quarks are clearly visible.
Strange matter - a new domain of nuclear physics
Relativistic heavy ion collisions offer the exciting possibility to produce exotic (meta-)stable states of nuclear matter containing (roughly) equal number of strangeness compared to the content in baryon number: Strangelets, i.e. small pieces of strange quark matter (SQM), were proposed as a signal of QGP formation. However, as their hadronic counterpart, also new multihypernuclear objects, i.e. small pieces of strange hadronic matter (SHM), may show up with rather very similar properties. This observation gives raise to the speculation that both states might have a strong overlap and correlation. In this overview we review the reasoning of both their stability and existence, the possible separation of strangeness necessary for their formation and the chances for their detection. (orig.)
Hadron spectroscopy from strangeness to charm and beauty
Quarks of different flavors have different masses, which will cause breaking of flavor symmetries of QCD. Flavor symmetries and their breaking in hadron spectroscopy play important role for understanding the internal structures of hadrons. Hadron spectroscopy with strangeness reveals the importance of unquenched quark dynamics. Systematic study of hadron spectroscopy with strange, charm and beauty quarks would be very revealing and essential for understanding the internal structure of hadrons and its underlying quark dynamics
Hadron spectroscopy from strangeness to charm and beauty
Zou, B.S., E-mail: zoubs@ihep.ac.cn [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Institute of High Energy Physics and Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences, Beijing 100049 (China)
2013-09-20
Quarks of different flavors have different masses, which will cause breaking of flavor symmetries of QCD. Flavor symmetries and their breaking in hadron spectroscopy play important role for understanding the internal structures of hadrons. Hadron spectroscopy with strangeness reveals the importance of unquenched quark dynamics. Systematic study of hadron spectroscopy with strange, charm and beauty quarks would be very revealing and essential for understanding the internal structure of hadrons and its underlying quark dynamics.
Non-Spherical Gravitational Collapse of Strange Quark Matter
Zade S S; Patil K D; Mulkalwar P N
2008-01-01
We study the non-spherical gravitational collapse of the strange quark null fluid.The interesting feature which emerges is that the non-spherical collapse of charged strange quark matter leads to a naked singularity whereas the gravitational collapse of neutral quark matter proceeds to form a black hole.We extend the earlier work of Harko and Cheng[Phys.Lett.A 266 (2000) 249]to the non-spherical case.
Higher dimensional strange quark matter solutions in self creation cosmology
Şen, R.; Aygün, S.
2016-03-01
In this study, we have generalized the higher dimensional flat Friedmann-Robertson-Walker (FRW) universe solutions for a cloud of string with perfect fluid attached strange quark matter (SQM) in Self Creation Cosmology (SCC). We have obtained that the cloud of string with perfect fluid does not survive and the string tension density vanishes for this model. However, we get dark energy model for strange quark matter with positive density and negative pressure in self creation cosmology.
Hadron spectroscopy from strangeness to charm and beauty
Zou, B. S.
2013-09-01
Quarks of different flavors have different masses, which will cause breaking of flavor symmetries of QCD. Flavor symmetries and their breaking in hadron spectroscopy play important role for understanding the internal structures of hadrons. Hadron spectroscopy with strangeness reveals the importance of unquenched quark dynamics. Systematic study of hadron spectroscopy with strange, charm and beauty quarks would be very revealing and essential for understanding the internal structure of hadrons and its underlying quark dynamics.
Weak Production of Strange Particles and $\\eta$ Mesons off the Nucleon
Alam, M Rafi; Alvarez-Ruso, L; Athar, M Sajjad; Vacas, M J Vicente
2015-01-01
The strange particle production induced by (anti)neutrino off nucleon has been studied for $|\\Delta S|=0$ and $|\\Delta S|=1$ channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are $f_\\pi$, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included $\\Sigma^*$(1385) resonance and for eta production $S_{11}$(1535) and $S_{11}$(1650) resonances are included.
Weak production of strange particles and η mesons off the nucleon
The strange particle production induced by (anti)neutrino off nucleon has been studied for |ΔS| = 0 and |ΔS| = 1 channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are fπ, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included Σ*(1385) resonance and for eta production S11(1535) and S11(1650) resonances are included
Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2016-04-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2016-04-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015 (Fig.~1). A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions; what is needed to understand the physics of resonances in QCD?; where does QCD lead us to expect resonances with exotic quantum numbers?; and what experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus.This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Lutz, Matthias F M; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B; Metag, Volker; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Steve L; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2015-01-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with ${\\it up}$, ${\\it down}$ and ${\\it strange}$ quark content were considered. For heavy-light and heavy-heavy meson systems, those with ${\\it charm}$ quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
A study of strange particle production in νμ charged current interactions in the NOMAD experiment
A study of strange particle production in νμ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles (K0s,Λ,Λ-bar) have been measured. Mean multiplicities are reported as a function of the event kinematic variables Eν, W2 and Q2 as well as of the variables describing particle behaviour within a hadronic jet: xF, z and pT2. Decays of resonances and heavy hyperons with identified K0s and Λ in the final state have been analyzed. Clear signals corresponding to K*±, Σ*±, Ξ- and Σ0 have been observed
Stability of strange dwarfs: a comparison with observations
We study the stability of strange dwarfs, superdense stars with a small self-confining core (Mcore < 0.02M⊙) containing strange quark matter and an extended crust consisting of atomic nuclei and degenerate electron gas. The mass and the radius of these stars are of the same order of magnitude as those of ordinary white dwarfs. It is shown that any study of their stability must examine the dependence of the mass on two variables, which can, for convenience, be taken to be the rest mass (total baryon number) of the quark core and the energy density ρtr of the crust at the surface of the quark core. The range of variation of these quantities over which strange dwarfs are stable is determined. This region is referred to as the stability valley for strange dwarfs. The mass and radius obtained from theoretical models of strange dwarfs are compared with observational data obtained through the HIPPARCOS program and the most probable candidate strange dwarfs are identified.