I'm in charge of organizing the poster session and wine tasting for the Confinement '08 meeting in Mainz. A list of the submitted posters is below. Please let me know of any errors/omissions.
In this conference series it has become a tradition, started by Nathan Isgur at Confinement III in 1998, for participants to bring a bottle of wine from their own country for the wine tasting. You are all encouraged to help maintain this tradition. Unfortunately for those flying it will mean checking luggage, but I hope the party will be worth it.
Images from before and after the wine tasting at the 2006 Confinement meeting:
Thanks, Mike
Grigor Alaverdyan (Bakhshi) galaverdyan@ysu.am EQUATION OF STATE OF NUCLEAR MATTER IN RELATIVISTIC MEAN-FEALD THEORY AND MAXWELLIAN PHASE TRANSITION TO STRANGE QUARK MATTER The equation of state of nuclear matter is considered in the framework of relativistic mean-field theory, when also the scalar-isovector delta-meson effective field is taken into account. The constants of the theory are numerically determined so that to reproduce the empirically known characteristics of symmetric nuclear matter at saturation density. The thermodynamic characteristics both asymmetric nuclear matter, and a betta-equilibrium hadron-electronic npe- plasma are studied. In the assumption, that the transition to strange quark matter is usual first order phase transition described by Maxwells construction, the changes of parameters of phase transition caused by presence of delta- meson field are in details investigated. For the description of a quark phase the advanced version of MIT bag model is used, in which the interactions between quarks are taken into account in the one-gluon exchange approach. For different values of bag constant in an interval 60-120 MeV/fm^3 the parameters of phase transition are determined and is shown, that the account of a delta-meson field results in reduction of pressure of phase transition and concentrations n1 and n2 at phase transition point. Thus the density jump parameter Lambda having the importance from the point of view of stability of infinitesimal quark core in a neutron star, is increased. The critical value Lambda=3/2 corresponds to value of bag parameter Bcr=69.3 MeV/fm^3. In the case of B3/2 is satisfied, and infinitesimal quark core is unstable. --------------------- Arifa Ali Khan (Regensburg) arifa.ali-khan@physik.uni-regensburg.de Matrix elements of heavy-light mesons from a fine lattice We have updated our calculation of matrix elements of heavy-light mesons on a quenched large lattice with lattice spacing a^-1 = 5 GeV and lattice size 40^3 X 80 and discuss the present status of our project. ---------------------- Petros Aslanyan (Laboratory of High Energy, JINR) paslanian@jinr.ru Review of exotic strange multibaryon states searches with $\Lambda$- hyperon and $K0_s$- meson systems in p+A collisions at momentum 10 GeV/c \begin{abstract} The hadron-nucleus, nucleus-nucleus collisions research program of NICA(JINR), FLAIR(GSI), AMADEUS(Frascati) and JPARC(KEK) will focus on the search for in-medium modifications of hadrons as a signal for high baryon densities. Experimental data as a stereo photographs from the 2m propane bubble chamber LHE, JINR with $V0$ particles have been analyzed for exotic strange multibaryon states searches. Review for exotic strange multibaryon states were obseved in the effective mass spectra of: 1)$\Lambda \pi^+$, $\Lambda \pi^-$,$\Lambda \pi^+\pi^-$, $\Lambda p$, and 2)$\Lambda K0_S$, $K0_S\pi^{\pm}$,$K0_s \pi^+\pi^-$ and $K0_Sp$ subsystems.The test of method has observed well known $\Sigma^{*+}$(1385), $K^{*\pm}$(892) and $\Lambda^*$ resonances. The width of $\Sigma^{*-}(1385)$ for p+A reaction isapproximately two time larger than that presented in PDG, because the observed experimental cross section of stopped in mediumnucleus $\Xi^-$ is 8 times larger than the cross section which is obtained by fritiof model with same experimental conditions. Results from searches of exotic strange multibaryon states with $\Lambda$ - hypron and $K0_S$ -meson systems were published \cite{lp}- \cite{pep08}. \end{abstract} \begin{thebibliography}{99} \bibitem{lp}P.Z. Aslanyan et al., Proc. Conf. on LEAP05,May 16-22, Bonn, 2005; AIP,v. 796, p.195, ISBN 0-7354-0284-1. Proc. I.Ya.Pomeranchuk and Physics at the Turn of Centuries, Moscow, 24-28 Jan. 2003. \bibitem{H}P.Z. Aslanyan, JINR Commun.,E-2001-265,2002. Nucl. Phys. B 75B(1999),p.63-65. \bibitem{theta}P.Aslanyan et al.,JINR, E1-2004-137,2004; Nuclear Physics A 755, 375, (2005). \bibitem{lk}P.Zh. Aslanyan et al.,Physics of Particles and Nuclei Letters, Vol. 3, No. 5,pp. 331-334, 2006.JINR Commun.,E1-2005-149, 2005. \bibitem{v0}P.Zh. Aslanyan et al.,Phys. of Part. and Nuclei Letters, Vol. 4, No. 1,pp. 99-108, 2007. JINR Commun.,E1-2005-150, 2005. \bibitem{spin06}P.Z. Aslanyan et. al., Proc. XVIII ISHEPP, Dubna,September 25-30, 2006. Proc. , Spin'06, October 2-7, Kyoto, Japan 2006, ISBN 978-0-7354-0423-6,AIP, v.915.ArXiv:hep-ex/0610086v1. \bibitem{IUTP07}P.Z. Aslanyan,Proc. IUTP'07,Schladming,Austria, 25-3 March, 2007. \bibitem{hadron}P.Z. Aslanyan,Proc. on XII Int. Confereence Hadron Spectroscopy, Frascati, 8-12 October,2007; ArXiv:hep/ex-0710.4322v2. \bibitem{ws08}P.Z. Aslanyan,Proc. the XLII PNPI Winter School on Nuclear and Particle Physics,St.Petersburg, Repino, February 18 - February 23, 2008. \bibitem{pep08)P.Zh. Aslanyan et al.,Physics of Particles and Nuclei,unpublished,2008. \end{thebibliography} ----------------------- Afsaneh Bazrafshan (Shiraz University) afsoon_bazrafshan@yahoo.com Analysis of Eta Photo-Production By using isobar model and the latest data, the structure function of Eta particle is calculated in the process of photo-production. This calculation is carried out for photon energy range of 0.750-3 GeV. The variations of the structure function are given in terms of scattering angle for different incoming photon energy. ------------- Afsaneh Bazrafshan (Shiraz University) afsoon_bazrafshan@yahoo.com Quark-Gluon Plasma Model and Origin of Magic Numbers Using Boltzman distribution in a quark-gtuon plasma sample it is possible to obtain all existing magic numbers and their extensions without applying the spin and spin-orbit couplings. In this model it is assumed that in a quark-gluon thermodynamic plasma, quarks have no interactions and they are trying to form nucleons. Considering a lattice for a central quark and the surrounding quarks, using a statistical approach to find the maximum number of microstates, the origin of magic numbers is explained and a new magic number is obtained. -------------- Igor Bogolubsky (JNR Dubna) bogolubs@lxpub04.jinr.ru Landau gauge gluon and ghost propagators in 4D $SU(3)$ gluodynamics on large lattices: recent results I.L.Bogolubsky,E-M.Ilgenfritz, M.Mueller-Preussker,A.Sternbeck We present recent results for the Landau gauge gluon and ghost propagators in $SU(3)$ pure gauge theory at Wilson $\beta=5.7$ for lattice sizes up to $96^4$ corresponding to physical volumes up to $(15.8 {\rm~fm})^4$. Considerable attention is paid to finite-volume and Gribov copy effects. We employ a gauge-fixing method that combines a simulated annealing algorithm with finalizing overrelaxation. In the infrared region $q^2 \le 0.01 {\rm~GeV}^2$ we find the gluon propagator to become flat as a function of $q^2$ with a weak volume dependence. Also the ghost dressing function seems to tend to a constant value in the deep infrared ($q^2 \to 0$). ------------------------ Jorn Boomsma (Vrije Universiteit Amsterdam) jboomsma@few.vu.nl Spontaneous CP-violation in the strong interaction at theta = pi. As is well-known, spontaneous CP-violation in the strong interaction is possible at theta = pi, known as Dashen's phenomenon [1]. This phenomenon has been studied extensively in chiral perturbation theory, for example, by Creutz [2] who has investigated its dependence on the quark masses for three flavors. In this talk the two-flavor NJL model at theta = pi will be discussed. It turns out that the occurrence of spontaneous CP-violation depends on the strength of the 't Hooft determinant interaction, which describes the effect of instanton interactions. Apart from the dependence of the phase-structure on the couplings, we have also analyzed the dependence on the quark masses, temperature, baryon and isospin chemical potential. The latter shows interesting modifications of the pion condensed phase first discussed by Son and Stephanov [3]. [1] R. Dashen, Phys. Rev. D 3, 1879 (1971). [2] M. Creutz, Phys. Rev. Lett. 92, 201601 (2004). [3] D.T. Son and M.A. Stephanov, Phys. Rev. Lett. 86, 592 (2001). ------------------------- Falk Bruckmann (U. Regensburg) falk.bruckmann@physik.uni-regensburg.de How instantons survive the phase transition ---------------- Marco Cardoso (Centro de Física Teórica de Partículas - Instituto Superior Técnico) mjdcc@cftp.ist.utl.pt Static potential in three-body hybrids and glueballs We study the quark-antiquark-gluon system in SU(3) lattice QCD for different geometries, discussing the contribution of two and three-body terms for the static potential and possible existence of repulsion between confining strings. Furthermore, we propose a wilson loop operator for extracting the three gluon static potential from lattice QCD and show results for the three-gluon potential ---------------- Maxim Chernodub (ITEP, Moscow) Maxim.Chernodub@itep.ru Electric-magnetic asymmetry of the dimension-2 condensate and the phases of Yang-Mills theory We study the finite-temperature behavior of the A^2 condensate in the Landau gauge of SU(2) Yang--Mills theory on the lattice in a wide range of temperatures. The asymmetry between the electric (temporal) and magnetic (spatial) components of this unconventional dimension-2 condensate is a convenient ultraviolet-finite quantity which possesses,as we demonstrate, unexpected properties. The low-temperature behavior of the condensate asymmetry suggests that the mass of the lowest thermal excitation in the condensate is unexpectedly low, about 200 MeV, which is much smaller than the glueball mass. The asymmetry is peaked at the phase transition being a monotonically decreasing function in the deconfinement phase. A symmetric point is reached in the deconfinement phase at a temperature approximately equal twice the critical temperature. The behavior of the electric-magnetic asymmetry of the condensate separates the phase diagram of Yang-Mills theory into three regions. We suggest that these regions are associated with the condensed, liquid and gaseous states of the confining gluonic objects, the Abelian monopoles. ------------------- Hilmar Forkel forkel@ift.unesp.br GLUEBALL CORRELATORS AS HOLOGRAMS We investigate the dynamical content of both hard- and soft-wall approximations to holographic QCD by deriving the corresponding glueball correlation functions and by confronting them with a variety of QCD results. We further calculate the glueball decay constants in both holographic duals, discuss emerging limitations and improvement strategies, and comment on a recent attempt to generalize the glueball correlator in the soft-wall background. ------------------ Mohammad Ghanaatian (Shiraz University) m_ghanatian57@yahoo.com Quark-Gluon Plasma Model and Origin of Magic Numbers Using Boltzman distribution in a quark-gtuon plasma sample it is possible to obtain all existing magic numbers and their extensions without applying the spin and spin-orbit couplings. In this model it is assumed that in a quark-gluon thermodynamic plasma, quarks have no interactions and they are trying to form nucleons. Considering a lattice for a central quark and the surrounding quarks, using a statistical approach to find the maximum number of microstates, the origin of magic numbers is explained and a new magic number is obtained. --------------------- Mohammad Ghanaatian (Shiraz University) m_ghanatian57@yahoo.com Physical Conditions for Nucleosynthesis in Early Universe In this research paper the required physical conditions for the formation and stability of nuclei particularly endothermic nuclei with mass number greater than to which is an open astrophysical question have been investigated. Using the debye layer mechanism, nuclear surface energy, Fermi energy and coulomb repulsion energy it is possible to find conditions under which the process of nucleation is permitted in early universe. Our numerical calculations indicate that about 200 second after the big bang at temperature of about 100 KeV and subrelativistic region with nucleon density nearly equal to normal nuclear density namely, ~10^38 cm^(-3) all endothermic and exothermic nuclei have been formed. ------------------------- Francesco Giacosa (ITP, Goethe University, Frankfurt) giacosa@th.physik.uni-frankfurt.de Radiative Phi decays with derivative interactions We study the line shapes of radiative $\phi$-decays involving virtual $f_{0}(980)$ and $a_{0}(980)$ mesons which decay, via derivative couplings, to $\pi^{0}\pi^{0}$ and $\pi^{0}\eta$ respectively. After developing the formalism for derivative interactions at one-loop level, we show that they can reproduce the measured peaked line shapes of $\phi$-decays without including kaon loops. --------------- Floriana Gianuzzi (University of Bari and INFN) floriana.giannuzzi@ba.infn.it Meson spectrum and tetraquarks through AdS/QCD potential Authors: M.V. Carlucci, F. Giannuzzi, G. Nardulli, M. Pellicoro, S. Stramaglia AdS/QCD correspondence is able to predict quark-antiquark potential in the static limit. We use this piece of information together with the Salpeter equation (Schroedinger equation with relativistic kinematics) and a short range hyperfine splitting potential to determine quark masses and quark potential parameters. A discussion of heavy diquark masses, based on the hypothesis of a diquark-antidiquark structure is also presented. based on arXiv:0711.2014 [hep-ph] -------------------- Jeff Greensite (San Francisco State University) jgreensite@gmail.com Confinement and Spontaneous Gauge Symmetry Breaking Spontaneous gauge symmetry breaking is a little ambiguous, in the sense that only a global subgroup of a local gauge symmetry can break spontaneously, and there are many different subgroups. Various confinement criteria and confinement scenarios focus on whether one or another of these subgroups is realized in a symmetric or broken phase. We show here that different global subgroups of the gauge symmetry can break at different places in the space of couplings; moreover, such transitions can occur at couplings where there may be no physical transition whatever to or from a confining phase. These facts have implications for the Kugo-Ojima and the Coulomb confinement criteria, as well as the dual-superconductivity scenario. -------------- Hassan Hassanabadi (Sharood University of Technology) h.hasanabadi@shahroodut.ac.ir Hyperspherical approach to description of a relatively general hypercenteral potential problem The hyperspherical coordinates method (HCM), which is based on collective variables, allows one to get spectral characteristics and devTelop the classification of excited states. A mathematical method is presented for solving the Schr\"{o}dinger equation for any hypercentral potential of the from $V(x)=\sum {G_{z}x^z}$for a system of identical body forces. The obtained energy values are in agreement with those obtained using variational method. ------------------- Hassan Hassanabadi (Shahrood university of technology) h.hasanabadi@shahroodut.ac.ir Spectrum of Pentaquark and Spin-Isospin Dependence The constituent quark model (CQM) has recently been widely used for the description of the internal structure of Pentaquarks. The Pentaquark spectrum is usually described well, although various models are quite different. However, the study of Pentaquark spectroscopy is not sufficient to distinguish among the various forms of quark dynamics. It would be interesting to consider the effect of an extra residual interaction among the quarks, which contains a dependence on isospin (or flavour). In the Chiral Constituent Quark model the non-confining part of the potential is provided by the interaction with the Goldstone bosons, giving rise to a spin- and isospin-dependent part which is crucial for the description of the spectrum for energies lower than 1.7 GeV. In this work we have introduced an improved form of the hyperfine interaction and isospin dependent quark potential. The resulting description of the Pentaquark spectrum was found to be satisfactory and not only we have included confinement potential at large separations but also color charge and non-confining hyperfine interaction potentials. This combination of potentials yields spectra which are very close to the ones obtained in experiments. -------------------- Markus Huber (Uni Graz) markus.huber@uni-graz.at Infrared Behavior of Three-Point Functions in Landau Gauge Yang-Mills Theory The dependence of the three-gluon and ghost-gluon vertices on the momentum configuration in the infrared is investigated employing Dyson-Schwinger equations. In a semi-perturbative approach we confirm the results from a power counting analysis, which show - in addition to the uniform infrared behavior - divergences if only a single momentum vanishes. We explicitly calculate the corresponding exponents. --------------------- Yoshiaki Koma (Numazu College of Technology) koma@numazu-ct.ac.jp Momentum dependence of the topological susceptibility and its derivative at zero momentum with overlap fermions The derivative of the topological susceptibility at zero momentum is related to the gluonic contribution to the proton spin in the chiral limit. This quantity also affects the Witten-Veneziano formula for the eta and eta' masses. We investigate the momentum dependence of the topological susceptibility using lattice QCD simulations with overlap fermions, which preserve exact chiral symmetry on the lattice and provide a powerful tool for investigating the topological structure of the QCD vacuum. ---------------- Gennady Kozlov (JINR) kozlov@jinr.ru The flux-tube phase transition and bound states at high temperatures We consider the phase transition in the dual Yang-Mills theory at finite temperature T. The phase transition is associated with a change (breaking) of symmetry. The effective mass of the dual gauge field is derived as a function of T-dependent gauge coupling constant. We investigate the analytical criterion constraining the existence of a quark-antiquark bound states at temperatures higher than the temperature of deconfinement. ---------------- Alexander Laschka (Technische Universitaet Muenchen) alaschka@ph.tum.de The heavy quark-antiquark potential from lattice and perturbative QCD The quark-antiquark potential in perturbative QCD suffers from ambiguities. We show how to derive a short-distance potential that satisfies continuity constraints and can be matched to results from lattice QCD simulations at intermediate distances. The static potential as well as 1/m corrections will be discussed. ---------------- Wolfgang Lucha (Austrian Acedemy of Sciences) Wolfgang.Lucha@oeaw.ac.at Full Salpeter Equation with Confining Interactions: Analytic Stability Proof The most popular three-dimensional reduction of the Bethe-Salpeter formalism for the description of bound states within relativistic quantum field theory is the Salpeter equation, obtained as instantaneous limit of the Bethe-Salpeter equation under the additional assumption of free propagation of the bound-state constituents. Unfortunately, depending on the assumed Lorentz structure of the Bethe-Salpeter kernel the solutions of the Salpeter equation with confining interactions may exhibit instabilities, probably related to the Klein paradox. As illustrated by the example of harmonic-oscillator potentials, for confining interactions of time-component Lorentz-vector nature the stability of the Salpeter solutions can be demonstrated by fully analytic arguments, supporting thereby the findings of several numerical studies. Moreover, the very same analyses may provide insight into the reasons why, for Lorentz structures different from the time-component Lorentz-vector case, instabilities arise, at least in certain regions of the parameter space. ----------------- Wolfgang Lucha and D. Melikhov (both HEPHY, Vienna) "Extracting hadron parameters by dispersive sum rules" We discuss the extraction of the parameters of individual hadronic bound states by dispersive sum rules. Making use of the exactly solvable quantum-mechanical harmonic-oscillator model, we are able to demonstrate unambiguously that the independence of the form factor of the ground state from the Borel parameter in the stability window does not necessarily lead to the extraction of the true form factor. -------------------- Patricia Magalhes (IF-Universty of Sao Paulo) patricia@if.usp.br Low-energy poles at $K\pi$ amplitude A simple algebraic expression is presented for the two lowest poles of the elastic $K\pi$ amplitude. --------------------- Ajay Majethiya, Bhavin Patel , Ajay Kumar Rai, and P C Vinodkumar ajay.phy@gmail.com Properties of doubly charmed baryons in the quark-diquark model Baryons containing two heavy quarks are important and interesting systems to study the quark-diquark structure of baryons and to understand the dynamics of QCD at hadronic scale. The Selex Collaboration [1] has recently reported the discovery of ¥cc with a mass of 3:519 GeV . However, other groups such as Babar [2], Belle [3] and Focus [4] have all failed to confirm this state. So there is a demand to review this state both theoretically and experimentally. We report here the spectra and magnetic moments of ccq(q in u; d; s) systems using coulomb plus Martin potential. Here the two heavy quarks are considered for the diquark states. The same potential form is used for the diquark interaction as well as for the quark-diquark interaction. The chromomagnetic one gluon exchange interaction are perturbatively treated here to get the masses of JP = 1/2+ and JP = 3/2+ states. Accordingly, we obtain Sigma++ cc (3520,3580), Sigma+ cc (3522, 3586) and Omega+cc (3564, 3669) states of the ccq ( 1/2+; 3/2+) combinations. Our predictions are in accordance with the selex result for Sigma++ cc (3519) and other model predictions. Predictions of other properties of these ccq systems will be presented in detail. References [1] A. Ocherashvili et al. [SELEX Collaboration], Phys. Lett. B 628, 18 (2005). [2] B. Aubert et al. [BABAR Collaboration], Phys. Rev. D 74, 011103 (2006). [3] R. Chistov et al. [BELLE Collaboration], Phys. Rev. Lett. 97, 162001 (2006). [4] S. P. Ratti, Nucl. Phys. Proc. Suppl. 115, 33 (2003). ------------------- Raka Dona Ray Mandal (Dept of Physics, Presidency College, Kolkata 700073, India) raka.raymandal@gmail.com Glitches in Strange Pulsars Strange stars have been proposed as a variant of compact stars. These stars are composed of beta-stable strange quark matter (SQM) which is expected to be absolutely stable [1].The stable range of mass (1 M_{\bigodot}- 1.5 M{\bigodot}) and radius (8 Km -9 Km) for strange stars calculated within the framework of the bag model are quite close to those for neutron stars [2] . These stars can also sustain an accreted hadronic matter crust of thickness of about one-tenth of the radius of the star separated from the interior by a thin electron cloud [3].However, the existence of strange pulsar, i.e. highly magnetized rotating strange star, is still questioned. One major objection arises due to its limitation to exhibit glitch. In this work we use a realistic strange star model [4] to demonstrate that a strange pulsar, enveloped in a accreted normal matter crust, can give rise to: (i) glitch and (ii) the strength of the glitch is expected to be small ( DW/W=10^{-11} where W is the angular frequency of the star and DW is the change in angular frequency). The model we use employs (a) a mean field derived from a two-body potential incorporating asymptotic freedom with a deconfinement transition and (b) a density dependent ansatz for the quark mass incorporating restoration of chiral symmetry at high density.This model gives the absolutely stable SQM [5]. The model has been successfully used to describe rotating strange stars [6]. Considering the interaction potential Vij= - V0 (\lambda_{i} \lambda_{j}) ( Si Sj ) *exp( {-\sigma^2} {{r}_ ij}^2) it has been shown that ud and ss pairs can be formed within the rotating strange star [7]. As these pairs are expected to be superconducting and the ud pairs are more favorable particularly for millisecond pulsars [8],there is likely to be an attractive interaction between these positively charged pairs and the negatively charged electron cloud separating the interior from the crust. This leads to a coupling between the crust and the interior. Hence, if there is any change in the angular momentum of the interior within the rotating star, the crust is expected to spin up and result into glitch. The change in the angular momentum of the interior may arise from motion of the superconducting vortices, which are likely to be formed by the rotating superconductor .The strength of the glitch will depend on (i) number of vortices formed within the interior , (ii) amount of angular momentum associated with each vortex,(iii) moment of inertia of the crust and (iv) coupling between the crust and the interior. We calculate the moment of inertia of the crust using the Byam -Pethick -Sutherland parameters. The number of superconducting vortices is estimated from the Ginzburg - Landau free energy of the system and the angular momentum associated with each vortex is calculated. The result shows the strength of the glitch is ~10^{-11} . Our result is supported very well by the micro glitch observed recently in a millisecond pulsar B1821- 24. References: [1] Witten E, (1984), PRD 30, 272 [2] Haensel P., and Jerzak A. J.,(1989) Acta Phys.Pol., B 20, 141 [3] Weber F.,(1999)"Pulsars as Astrophysical Laboratories for Nuclear and Particle Physics" IOP publishing [4] Dey M., Bombaci I., Dey J., Ray S., Samanta B.C., (1998) Phys Lett B 438,123 [5] Li X.D, Bombaci I., Dey M., Dey J., van den Heuvel E.P.J.,(1999) PRL 83,3776 [6] Gondek -Rosinska D., Bulik T., Zdunik L., Gourgoulhon E., Ray S.,Dey J., Dey M.,(2000) A&A 363, 1005 [7] Sinha M., Dey M., Ray S., Dey J.,2002, MNRAS 337,1368 [8] Ray Mandal R..D.,Sinha M., Bagchi M., Konar S., Dey M.,dey J., (2006)MNRAS365,1383 ------------- Hrayr Matevosyan (Nuclear Theory Center, Indiana University) hmatevos@indiana.edu Recent Advances in Numerical Approach to Coulomb Gauge QCD We calculate the ghost two-point function in Coulomb gauge QCD with the Greensite-Olejnik effective model vacuum gluon wavefunction using Monte Carlo integration, where gauge configurations are ensured to be within Gribov region. This approach, proven in our previous simple model studies by comparing with analytical results, provides an invaluable tool for exploring the properties of the non-perturbative QCD vacuum described by the model wavefunctional, where the analytical studies of this more sophisticated model are yet unfruitful. This approach allows us to study the possible critical behavior of the coupling constant, as well as the Coulomb potential derived from the ghost dressing function. --------------------- Majid Monemzadeh (University of Kashan) monem@kashanu.ac.ir Fine Structure Coefficient and Strong Nuclear Potential Variations in Heavy Mesons In heavy mesons we consider the strong potential with a linear term. Fine structure of strong interaction of mesons contain t quark in pseudoscalar and vector mesons has been estimated with consideration of coupling effect of spin's quarks and their masses. The results confirm falling of fine structure constant of strong interaction with respect to increasing the masses of mesons. ------------------- Fatemeh Moujie (physics graduate student, Shiraz University, Iran) fatemeh_mojie@yahoo.com Neutral pion photo-production on the proton up to 1.6 Gev Neutral pion photo-production on the proton is studided using a unitary isobar model. The model contains Born terms, contributions from vector -meson exchanges and nucleon resonances.This model (MAID 2007) is implemented as a part of the MAID program (the MAID program can be accessed from the webpage : http://www.kph.uni-mainz.de) . We have compared the results obtained from this model with the BONN-ELSA-CB experimental data for differential and total cross section. Comparison is carried out for photon energy range of 0.3 - 1.6 Gev. We also have investigated the role of different nucleon resonances in differential cross section in this model. --------------- Denise Neudecker (Atomic Institut, Vienna University of Technology) e0325352@student.tuwien.ac.at Thick- Center- Vortex- Model and the Coulombic Potential The potentials for various SU(3) representations are calculated by means of an analytical model for thick- center vortices. We discuss the influence of fluctuations of non- quantized, closed magnetic flux lines of short range on the Coulombic part of the potential and the self- energy. We fit the model's parameters to lattice data. --------------- Alireza Olamaei (Shiraz University) alireza_olamaei@yahoo.com L/T Cross-Section Separation for Electroproduction of Neutral Pion In this analysis Rosenbluth separation method is applied to calculate the longitudinal and transverse cross sections in neutral pion electroproduction for four measured energy and square momentum values where the latest data is available, namely W=1.2-1.5 (GeV) and Q2=1.15-1.01 (GeV/c)2. ----------------- Mikhail Polikarpov (ITEP, Moscow) polykarp@itep.edu Entanglement entropy in lattice gauge theories We study entanglement entropy for four-dimensional SU (2) lattice gauge theory at finite temperature. There exist UV divergent and finite parts of the entanglement entropy. The phase transition w.r.t. the size of the boundary is observed at temperatures above the deconfinement transition. This behaviour is in agreement with recent theoretical studies of conformal field theories and large-N confining gauge theories in the framework of AdS/CFT correspondence -------------------------- Markus Quandt (Institut für Theoretische Physik, Universität Tübingen) quandt@tphys.physik.uni-tuebingen.de Ghost propagator and the Coulomb form factor in Coulomb gauge We calculate both the ghost propagator and the Coulomb form factor in Coulomb gauge on the lattice, using an improved gf. scheme that was previously shown to have significant impact on the gluon propagator in the IR. For the Coulomb form factor, we do not rely on translational invariance and compute the relevant large matrix inversions for each configuration exactly using improved Fourier techniques. From our findings, we investigate finite size effects, multiplicative renormalisation and possible scaling violations in the form factors. After proper residual gauge fixing, we also compute the A0-A0 correlator and compare to the Coulomb form factor. Finally, we also compare our findings to previous lattice investigations and recent continuum results in the variational approach. ------------------------ Ajay Kumar Rai (Physics Section, ASHD, Sardar Vallabhbhai National Institute of Technology-Surat, 395 007, Gujarat, India.) akr@ashd.svnit.ac.in DECAY PROPERTIES OF $Q\bar Q$ MESONS IN POTENTIAL MODELS AND EFFECTIVE FIELD THEORIES {AJAY KUMAR RAI$^1$, J N PANDYA$^2$ Bhavin Patel$^3$ and P C VINODKUMAR$^3$ }\\ {$^1$Physics Section, Applied Sciences and Humanities Department, Sardar Vallabh National Institute of Technology, Surat - 395 007, Gujarat, INDIA.\\ akr@ashd.svnit.ac.in}\\ {$^2$Applied Physics Department, Faculty of Technology \& Engineering, The M S University of Baroda, Vadodara - 390 001, Gujarat, INDIA.\\ jnpandya@mail.com}\\ {$^3$Department of Physics, Sardar Patel University, Vallabh Vidyanagar, Anand, Gujarat 388 120, INDIA.\\ pothodivinod@yahoo.com}\\ The decay rates of mesons $Q \bar Q$ mesons ($Q\ \varepsilon \ {c, b}$) are studied in the NRQCD formalism in terms of their short distance and long distance coefficients. The long distance coefficients are obtained through phenomenological potential model description of the mesons [1-2]. The mass spectrum of the $c \bar c$, $b \bar b$ and $c \bar b$ mesons are reviewed in non-relativistic phenomenological quark antiquark potential of the type $V(r)=-\frac{\alpha_c}{r}+A r^{\nu}$, with $\nu$ varying from 0.5 to 2 [3]. The spin hyperfine and spin-orbit interactions are employed to obtain the masses of the pseudoscalar and vector mesons. The decay constants with QCD corrections are computed in this model as well as in the case of other potential models for comparison. The digamma and dileptonic decays of $c \bar c$ and $b \bar b$ mesons are investigated using some of the known potential models by incorporating radiative corrections up to the lowest order, bound state effects and contribution from quark/antiquark propagator. By incorporating the relativistic corrections of order $v^4$ to the heavy quarkonium decays into two photons, and the vector state into lepton pairs are computed within the NRQCD formalism. Our theoretical predictions of the decays of the $c \bar c$ and $b \bar b$ mesons and the results obtained from some of the other potential schemes are compared with the experimental values. The partial widths and life time of the Bc meson are also computed using the model parameters and are found to be in good accordance with the experimental values. References [1] G. T. Bodwin, E. Braaten and G. P. Lepage, Phys. Rev. D 51, 1125 (1995); D 55, (E) ( 1997). [2] G. T. Bodwin, H. S. Chung, D. Kang, J. Lee and C. Yu, Phys. Rev. D 77, 094017 (2008). [3] Ajay Kumar Rai, J. N. Pandya and P. C. Vinodkumar, J. Phys. G 31, 1453 (2005). ---------------- Jagmohan Singh Rana (H.N.B. Garwhal University, India) ranajms@gmail.com Dyons in Supersymmetric Restricted Quantum Chromodynamics(SRCD)by J M S RANA Department of Physics, HNB Garhwal University, SRT Campus , Badshahithaul(Tehri-Garhwal),India The Restricted Quantum Chromodynamics(RCD) formulated in terms of connections on global spaces has been supersymmetrized, in a general manner, taking only the topological part into considerations. Dyonic supermultiplets have been obtained for the N=1 supersymmetry quantum mechanically as well as in the supersymmetric version of Georgi-Glashow model for vanishing linear momentum and in the Clifford vacuum. Incorporating the Dyonic color charge and color spin induced as a result of fermion fractionization in Georgi- Glashow model(in presence of an isovector fermion field)into the Supersymmetric Restricted Chromodynamics in N=1 SUSY limit,the Lagrangian density has been constructed and SUSY Dyonic solutions have been obtained . Furthermore, the classical mass of the Dyon has been calculated by minimizing the background potential of theory. The eigen value equations of bosonic and fermionic fluctuations have been obtained in the dyonic background gauge and the corresponding one-loop corrections to the Dyonic mass are calculated and it has been shown that one-loop quatum corrections lead no change in classical mass of Dyon. --------------- Vladimir Sauli (CFTP IST Lisbon) sauli@cftp.ist.utl.pt Quark Schwinger-Dyson equation in temporal Euclidean space We present an elementary method to nonperturbatively obtain Greens function for timelike momenta. We assume there are no singularities in the first and third quadrants of the complex plane of space momentum components and performe a 3d analogue of Wick rotation. This procedure defines Greens functions in timelike Euclidean space. As an example we consider quark propagator in QCD. While for weak coupling, the method is obviously equivalent to perturbation theory, for realistic QCD coupling a complex part of the quark mass and reormalization wave function has been spontaneously generated even bellow standard perturbative threshold. Therefore, our method favoures a confinement mechanism based on the lack of real poles. ------------------- Arwed Schiller (Leipzig University) Arwed.Schiller@itp.uni-leipzig.de Higher-loop gluon and ghost propagators in Landau gauge from numerical stochastic perturbation theory We present higher loop results for the gluon and ghost propagator in Landau gauge on the lattice calculated in numerical stochastic perturbation theory (NSPT). We discuss in detail how to perform the different necessary limits in the NSPT approach and discuss a recipe to treat logarithmic terms by introducing ``finite lattice logs''. We find agreement with the one-loop results from standard lattice perturbation theory and estimate, from the non-logarithmic part of the propagators in two-loop order, the unknown constant contributions to the self-energies in the RI'-MOM scheme in Landau gauge. ------------------ Kai Schwenzer (Uni Graz) kai.schwenzer@uni-graz.at A mechanism for confinement in Landau gauge QCD We analyze the infrared fixed point structure of Landau gauge QCD and discuss the importance of these fixed points for physical phenomena like the confinement of quarks and chiral symmetry breaking. In addition to the uniform scaling limit when all momenta tend to zero the vertices feature also kinematic singularities when only a single gluon momentum vanishes. In the case of the quark-gluon vertex these soft singularities are non-perturbatively enhanced and provide a mechanism for the confinement of static color sources in quenched QCD. The obtained fixed points are only realized in the idealized situations of heavy respectively massless quarks. Since the unquenched, physical case depends on the current quark mass scales it is in between these limiting cases. This provides the chance to describe string breaking and deconfinement. ------------------ Stefan Strüber (Uni Frankfurt) strueber@th.physik.uni-frankfurt.de Role of the tetraquark in the chiral phase transition We investigate the implications of a tetraquark field on chiral symmetry restoration at nonzero temperature. In order for the chiral phase transition to be cross-over, as shown by lattice QCD studies, a strong mixing between scalar quarkonium and tetraquark fields is required. This leads to a light (~0.4 GeV), predominantly tetraquark state, and a heavy (~1.2 GeV), predominantly quarkonium state in the vacuum, in accordance with recently advocated interpretations of spectroscopy data. The mixing even increases with temperature and leads to an interchange of the roles of the originally heavy, predominantly quarkonium state and the originally light, predominantly tetraquark state. Then, as expected, the scalar quarkonium is a light state when becoming degenerate in mass with the pion as chiral symmetry is restored at nonzero temperature. ---------------- Peter Watson (University of Tübingen) watson@tphys.physik.uni-tuebingen.de Slavnov-Taylor Identities in Coulomb Gauge Yang-Mills Theory One of the prerequisites for a viable description of confinement is color charge conservation. In the context of the functional formalism in Coulomb gauge Yang-Mills theory, the Slavnov-Taylor identities for the Green's function appear crucial in this aspect. Moreover, it transpires that these identities form closed sets of nonlinear integral equations which gives rise to the hope that charge conservation may be enforced in practical nonperturbative calculations. ---------------- Axel Weber (University of Michoacan, Mexico) axel@ifm.umich.mx A generating functional for equal-time correlation functions The formulations of QCD or Yang-Mills theory in Coulomb gauge are attractive mainly because of the appearance of the confining color Coulomb potential. However, the usual covariant (four-dimensional) quantum field theoretic formulation is rather awkward in the Coulomb gauge. Partially successful analytic calculations so far have used alternative noncovariant approaches in three (spatial) dimensions. Our aim is to put this type of approaches on a firm and systematic basis. To this end, we develop a generating functional for the three-dimensional formulation that generates equal-time correlation functions. In fact, such a functinal is given directly in terms of the vacuum wave functional, however, in a perturbative expansion of the equal-time correlation functions, the vacuum wave functional has to be known, in principle, to the corresponding order. As a consequence, there are many contributions here that correspond to one and the same Feynman diagram in the covariant theory. A remarkable simplification occurs, however, on summing up these different contributions. For the relatively simpler case of a phi^4 theory, we analyze the possibility of developing new diagrammatic rules directly for the sum of all contributions that correspond to the same proper Feynman diagram. We discuss universality and the formulation of the analogues of Dyson-Schwinger equations for the equal-time correlation functions -------------------- Farhad Zolfagharpur (University of Mohaghegh Ardabili, Iran) zolfagharpour@uma.ac.ir The role of difference between proton and neutron structure functions and related harmonic oscillator parameter to shells mean square radius in the EMC effect of Al, Si and Cu nuclei In this investigation the neutron and proton GRV's structure function used to calculate nuclear structure function of Al, Si and Cu nuclei. The neutron and proton number of this nuclei are different, so it seems that this difference can not be neglected in the extraction of EMC ratio for this nuclei. We know that binding nucleons in different shells have different momentum distributions and one can relate these momentum distributions to shells mean square radius. In this investigation we considered these two phenomena to extract the EMC ratio for Al, Si and Cu nuclei. The extracted results show good agreement with the experimental data by sufficient depletion in the binding energy. ------------------------