Giacosa, Francesco
2016-01-01
Glueballs are predicted in various theoretical approaches of QCD (most notably lattice QCD), but their experimental verification is still missing. In the low-energy sector some promising candidate for the scalar glueball exist, and some (less clear) candidates for the tensor and pseudoscalar glueballs were also proposed. Yet, for heavier gluonic states there is much work to be done both from the experimental and theoretical points of view. In these proceedings, we briefly review the current status of research of glueballs and discuss future developments.
Scharre, D.L.
1982-01-01
It is expected from quantum chromodynamics (QCD) that glueballs, bound states which contain gluons but no valence quarks, should exist. To date, no conclusive evidence for glueballs has been presented. After a brief review of the expected properties and experimental signatures of glueballs the status of some glueball candidate states are discussed.
Configurational entropy of glueball states
Bernardini, Alex E.; Braga, Nelson R. F.; da Rocha, Roldão
2017-02-01
The configurational entropy of glueball states is calculated using a holographic description. Glueball states are represented by a supergravity dual picture, consisting of a 5-dimensional graviton-dilaton action of a dynamical holographic AdS/QCD model. The configurational entropy is studied as a function of the glueball spin and of the mass, providing information about the stability of the glueball states.
Conditional entropy of glueball states
Bernardini, Alex E; da Rocha, Roldao
2016-01-01
The conditional entropy of glueball states is calculated using a holographic description. Glueball states are represented by a supergravity dual picture, consisting of a 5-dimensional graviton-dilaton action of a dynamical holographic AdS/QCD model. The conditional entropy is studied as a function of the glueball spin and of the mass, providing information about the stability of the glueball states.
Close, Frank E.
2000-01-01
Glueball candidates and qqbar mesons have been found to be produced with different momentum and angular dependences in the central region of pp collisions. This talk illustrates this phenomenon and explains the phi and t dependences of mesons with JPC = 0++,0-+, 1++, 2++ and 2-+. For production of 0++ and 2++ mesons the analysis reveals a systematic behaviour in the data that appears to distinguish between qqbar and non-qqbar or glueball candidates. An explanation is given for the absence of 0-+ glueball candidates in central production at present energies and the opportunity for their discovery at RHIC is noted.
Close, Francis Edwin
2000-01-01
Glueball candidates and qqbar mesons have been found to be produced with different momentum and angular dependences in the central region of pp collisions. This talk illustrates this phenomenon and explains the phi and t dependences of mesons with JPC = 0++,0-+, 1++, 2++ and 2-+. For production of 0++ and 2++ mesons the analysis reveals a systematic behaviour in the data that appears to distinguish between qqbar and non-qqbar or glueball candidates. An explanation is given for the absence of 0-+ glueball candidates in central production at present energies and the opportunity for their discovery at RHIC is noted.
Brünner, Frederic; Rebhan, Anton
2014-01-01
We announce new results on glueball decay rates in the Sakai-Sugimoto model, a realization of holographic QCD from first principles that has only one coupling constant and an overall mass scale as free parameters. We extend a previous investigation by Hashimoto, Tan, and Terashima who have considered the lowest scalar glueball which arises from a somewhat exotic polarization of supergravity modes and whose mass is uncomfortably small in comparison with lattice results. On the other hand, the scalar glueball dual to the dilaton turns out to have a mass of about twice the mass of the rho meson (1487 MeV), very close to the scalar meson $f_0(1500)$ that is frequently interpreted as predominantly glue. Calculating the decay rate into two pions we find a surprisingly good agreement with experimental data for the $f_0(1500)$. We have also obtained decay widths for tensor and excited scalar glueballs, indicating universal narrowness.
Lindenbaum, S.J.
1983-08-03
If you assume as input axioms: (1) QCD is correct; and (2) the OZI rule is universal for weakly coupled glue in disconnected Zweig diagrams where the disconnection is due to the creation or annihilation of new flavor(s) of quark(s), then the BNL/CCNY g/sub T/(2010), g/sub T/'(2220) and g/sub T/(2360) observed in ..pi../sup -/p ..-->.. phi phi n are produced by 1-3 primary glueballs. One or two broad primary glueballs could in principle break down the OZI suppression and mix with one or two quark states which accidentally have the same quantum numbers and nearly the same mass. However the simplest explanation of the rather unusual characteristics of our data is that we have found a triplet of J/sup PC/ = 2/sup + +/ glueball states. Since our input axioms are in good agreement with experiments and merely represent modern QCD practice, we have very probably discovered 1-3 J/sup PC/ = 2/sup + +/ glueballs. The iota(1440) and the theta(1700) observed in J/psi radiative decay are glueball candidates. The pros and cons of which are discussed briefly here. 41 references.
Sergeenko, M N
2011-01-01
Glueballs are considered to be bound states of constituent gluons. Relativistic wave equation for two massive gluons interacting by the funnel-type potential is analyzed. Using two exact asymptotic solutions of the equation, we derive an interpolating mass formula and calculate glueball masses in agreement with the lattice data. We obtain the complex non-linear Pomeron trajectory, $\\alpha_P(t)$, in the whole region of $t$. The real part of the trajectory corresponds to the soft Pomeron, parameters of which are found from the fit of recent HERA data.
Toki, W. [Colorado State Univ., Ft. Collins, CO (United States). Dept. of Physics
1997-06-01
In these Summer School lectures, the author reviews the results of recent glueball searches. He begins with a brief review of glueball phenomenology and meson spectroscopy, including a discussion of resonance behavior. The results on the f{sub o}(1500) and f{sub J}(1700) resonances from proton-antiproton experiments and radiative J/{Psi} decays are discussed. Finally, {pi}{pi} and {eta}{pi} studies from D{sub s} decays and exotic meson searches are reviewed. 46 refs., 40 figs.
Scalar and Pseudoscalar Glueballs
Cheng, Hai-Yang
2009-01-01
We employ two simple and robust results to constrain the mixing matrix of the isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$: one is the approximate SU(3) symmetry empirically observed in the scalar sector above 1 GeV and confirmed by lattice QCD, and the other is the scalar glueball mass at 1710 MeV in the quenched approximation. In the SU(3) symmetry limit, $f_0(1500)$ becomes a pure SU(3) octet and is degenerate with $a_0(1450)$, while $f_0(1370)$ is mainly an SU(3) singlet with a slight mixing with the scalar glueball which is the primary component of $f_0(1710)$. These features remain essentially unchanged even when SU(3) breaking is taken into account. The observed enhancement of $\\omega f_0(1710)$ production over $\\phi f_0(1710)$ in hadronic $J/\\psi$ decays and the copious $f_0(1710)$ production in radiative $J/\\psi$ decays lend further support to the prominent glueball nature of $f_0(1710)$. We deduce the mass of the pseudoscalar glueball $G$ from an $\\eta$-$\\eta'$-$G$ mixing formalism...
The low lying glueball spectrum
Adam Szczepaniak; Eric Swanson
2003-12-18
The complete low-lying positive charge conjugation glueball spectrum is obtained from QCD. The formalism relies on the construction of an efficient quasiparticle gluon basis for Hamiltonian QCD in Coulomb gauge. The resulting rapidly convergent Fock space expansion is exploited to derive quenched low-lying glueball masses with no free parameters which are in remarkable agreement with lattice gauge theory.
Scalar Glueball Mixing and Decay
Burakovsky, L; Burakovsky, Leonid; Page, Philip R.
1999-01-01
We provide the first explanation of the counter-intuitive scalar glueball couplings to pseudoscalar mesons found in lattice QCD and predict hitherto uncalculated decay modes. Significant a_1 pi and (pi pi)_S (pi pi)_S couplings are found. We demonstrate the equivalence of linear and quadratic mass matrices for glueball-quarkonium mixing. The equivalence of formalisms which deal with a glueball-quarkonium basis and only a quarkonium basis is demonstrated. We show that the f_0(1500) is not the heaviest state arising from glueball-quarkonium mixing for a glueball mass consistent with lattice QCD. The masses and couplings of scalar mesons, as well as their valence content, are calculated.
Observation and phenomenology of glueballs
Lindenbaum, S.J.
1985-01-01
The experimental evidence and the relevant phenomenology of glueballs are reviewed. The opinion is expressed that the glueball resonance explanation is the only viable one for the data on g/sub T/, g/sub T/sup 1//, and g/sub T/sup 11//. It is shown that alternative explanations are either incorrect, or do not fit the data, or both, leading to the conclusion that these states are probably produced by glueballs. The OZI rule is explained. Glueball masses and width are considered. Some conclusions are drawn regarding an OZI suppressed reaction ..pi../sup -/p ..-->.. phi phi n. Glueball candidates from the J/psi radiative decay are discussed. 44 refs., 16 figs. (LEW)
Revision of exotic $0^{--}$ glueball
Pimikov, Alexandr; Kochelev, Nikolai; Zhang, Pengming
2016-01-01
We present the new results for the exotic glueball state $0^{--}$ in the framework of the QCD sum rules. It is shown that previously used three-gluon current does not couple to any glueball bound state. We suggest considering a new current which couples to this exotic state. The resulting values for mass and decay constant of the $0^{--}$ glueball state are $M_G=6.3^{+0.8}_{-1.1}$ GeV and $F_G=67 \\pm 6 $ keV, respectively.
Giacosa, Francesco; Sammet, Julia; Janowski, Stanislaus
2017-06-01
We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar, (axial-)vector, as well as pseudovector and excited vector mesons in the framework of a model of QCD. While absolute values of widths cannot be predicted because the corresponding coupling constants are unknown, some interesting branching ratios can be evaluated by setting the mass of the yet hypothetical vector glueball to 3.8 GeV as predicted by quenched lattice QCD. We find that the decay mode ω π π should be one of the largest (both through the decay chain O →b1π →ω π π and through the direct coupling O →ω π π ). Similarly, the (direct and indirect) decay into π K K*(892 ) is sizable. Moreover, the decays into ρ π and K*(892 )K are, although subleading, possible and could play a role in explaining the ρ π puzzle of the charmonium state ψ (2 S ) thanks to a (small) mixing with the vector glueball. The vector glueball can be directly formed at the ongoing BESIII experiment as well as at the future PANDA experiment at the FAIR facility. If the width is sufficiently small (≲100 MeV ) it should not escape future detection. It should be stressed that the employed model is based on some inputs and simplifying assumptions: the value of glueball mass (at present, the quenched lattice value is used), the lack of mixing of the glueball with other quarkonium states, and the use of few interaction terms. It then represents a first step toward the identification of the main decay channels of the vector glueball, but shall be improved when corresponding experimental candidates and/or new lattice results will be available.
Glueball Masses in Relativistic Potential Model
Shpenik, A; Kis, J; Fekete, Yu
2000-01-01
The problem of glueball mass spectra using the relativistic Dirac equation is studied. Also the Breit-Fermi approach used to obtaining hyperfine splitting in glueballs. Our approach is based on the assumption, that the nature and the forces between two gluons are the short-range. We were to calculate the glueball masses with used screened potential.
A Lattice Study of the Glueball Spectrum
LIU Chuan
2001-01-01
Glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU(3)gauge theory. The smallest spatial lattice spacing is about 0.08 fm which makes the extrapolation to the continuum limit more reliable. In particular, attention is paid to the scalar glueball mass which is known to have problems in the extrapolation. Converting our lattice results to physical units using the scale set by the static quark potential,we obtain the following results for the glueball masses: MG(0++) = 1730(90) MeV for the scalar glueball mass and MG(2++) = 2400(95) MeV for the tensor glueball.
Ralston, J P
2003-01-01
Recently Buniy and Kephart made an astonishing empirical observation, which anyone can reproduce at home. Measure the {\\it lengths} of closed knots tied from ordinary rope. The ``double do-nut'', and the beautiful trefoil knot are examples. Tie the knots tightly, and glue or splice the tails into a seamless unity. Compare two knots with corresponding members of the mysterious particle states known as ``glueball'' candidates in the literature. Propose that the microscopic glueball mass ought to be proportional to the macroscopic mass of the corresponding knot. Fit two parameters, then {\\it predict} 12 of 12 remaining glueball masses with extraordinary accuracy, knot by knot. Here we relate these observations to the fundamental gauge theory of gluons, by recognizing a hidden gauge symmetry bent into the knots. As a result the existence and importance of a gluon mass parameter is clarified. Paradoxically forbidden by the usual framework, the gluon mass cannot be expressed in the usual coordinates, but has a natu...
Lindenbaum, S.J.
1984-01-01
There are two methods discussed by which glueballs might be found. In the first, an OZI suppressed channel with variable mass is used, such as the reaction ..pi../sup -/p ..-->.. phi phi n. The breakdown of the OZI suppression is the glueball signal. The OZI suppression is a filter letting glueballs pass while strongly rejecting conventional hadronic states. The other method is to look in a channel enriched in gluons such as the radiative decay of the J/psi and search for new phenomena, such as the iota(1440), the theta(1640), and the zeta(2220). It is anticipated that the next step in nested gauge-gauge groups might be some new strong color interaction conceptually similar to hypercolor, technicolor, or extended technicolor. 43 refs., 13 figs. (LEW)
Giacosa, Francesco; Janowski, Stanislaus
2016-01-01
We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar, (axial-)vector, as well as pseudovector and excited vector mesons. By setting the mass of this yet hypothetical vector glueball to 3.8 GeV as predicted by Lattice QCD, many branching ratios can be computed and represent a parameter-free prediction of our approach. We find that the decay mode $\\omega\\pi\\pi$ should be one of the largest (both through the decay chain $\\mathcal{O}\\rightarrow b_{1}\\pi\\rightarrow$ $\\omega\\pi\\pi$ and through the direct coupling $\\mathcal{O}\\rightarrow\\omega\\pi\\pi$)$.$ Similarly, the (direct and indirect) decay into $\\pi KK^{\\ast}(892)$ is sizable. Moreover, the decays into $\\rho\\pi$ and $K^{\\ast}(892)K$ are, although subleading, possible and could play a role in explaining the $\\rho\\pi$ puzzle of the charmonium state $\\psi(2S)$ thank to a (small) mixing with the vector glueball. The vector glueball can be directly formed at the ongoing BESIII experiment as well as at the future PANDA exper...
Ultraviolet asymptotics of glueball propagators
Bochicchio, M
2013-01-01
We point out that perturbation theory in conjunction with the renormalization group (RG) puts a severe constraint on the structure of the large-N non-perturbative glueball propagators in SU(N) pure YM, in QCD and in n=1 SUSY QCD with massless quarks, or in any confining asymptotically-free gauge theory massless in perturbation theory. For the scalar and pseudoscalar glueball propagators in pure YM and QCD with massless quarks we check in detail the RG-improved estimate to the order of the leading and next-to-leading logarithms by means of a remarkable three-loop computation by Chetyrkin et al. We investigate as to whether the aforementioned constraint is satisfied by any of the scalar or pseudoscalar glueball propagators computed in the framework of the AdS String/ large-N Gauge Theory correspondence and of a recent proposal based on a Topological Field Theory underlying the large-N limit of YM. We find that none of the proposals for the scalar or the pseudoscalar glueball propagators based on the AdS String/...
Glueballs and vector mesons at NICA
Parganlija, Denis [Technische Universitaet Wien, Institut fuer Theoretische Physik, Vienna (Austria)
2016-08-15
Two interconnected fields of interest are suggested for NICA. Firstly, existence of glueballs is predicted by the theory of strong interaction but -even after decades of research- glueball identification in the physical spectrum is still unclear. NICA can help to ascertain experimental glueball candidates via J/Ψ decays whose yield is expected to be large. Importance of glueballs is not limited to vacuum: since they couple to other meson states, glueballs can also be expected to influence signatures of chiral-symmetry restoration in the high-energy phase of strong dynamics. Mass shifting or in-medium broadening of vector and axial-vector mesons may occur there but the extent of such phenomena is still uncertain. Additionally, glueball properties could also be modified in medium. Exploration of these issues is the second suggested field of interest that can be pursued at NICA. (orig.)
Decay modes of the excited pseudoscalar glueball
Eshraim, Walaa I
2016-01-01
We study three different chiral Lagrangians that describe the two- and three-body decays of an excited pseudoscalar glueball, $J^{PC}=0^{*-+}$, into light mesons and charmonium states as well as into a scalar and pseudoscalar glueball. We compute the decay channels for an excited pseudoscalar glueball with a mass of $3.7$ GeV and consider a ground state pseudoscalar glueball of mass $2.6$ GeV, following predictions from lattice QCD simulations. These states and channels are in reach of the PANDA experiments at the upcoming FAIR facility experiment. We present the resulting decay branching ratios with a parameter-free prediction.
Perturbative Computation of Glueball Superpotentials
Dijkgraaf, R; Lam, C S; Vafa, C; Zanon, D
2003-01-01
Using N=1 superspace techniques in four dimensions we show how to perturbatively compute the superpotential generated for the glueball superfield upon integrating out massive charged fields. The technique applies to arbitrary gauge groups and representations. Moreover we show that for U(N) gauge theories admitting a large N expansion the computation dramatically simplifies and we prove the validity of the recently proposed recipe for computation of this quantity in terms of planar diagrams of matrix integrals.
Perturbative computation of glueball superpotentials
Dijkgraaf, R.; Grisaru, M. T.; Lam, C. S.; Vafa, C.; Zanon, D.
2003-10-01
Using N=1 superspace techniques in four dimensions we show how to perturbatively compute the superpotential generated for the glueball superfield upon integrating out massive charged fields. The technique applies to arbitrary gauge groups and representations. Moreover, we show that for U(N) gauge theories admitting a large N expansion the computation dramatically simplifies and we prove the validity of the recently proposed recipe for computation of this quantity in terms of planar diagrams of matrix integrals.
Perturbative computation of glueball superpotentials
Dijkgraaf, R.; Grisaru, M.T.; Lam, C.S.; Vafa, C.; Zanon, D
2003-10-30
Using N=1 superspace techniques in four dimensions we show how to perturbatively compute the superpotential generated for the glueball superfield upon integrating out massive charged fields. The technique applies to arbitrary gauge groups and representations. Moreover, we show that for U(N) gauge theories admitting a large N expansion the computation dramatically simplifies and we prove the validity of the recently proposed recipe for computation of this quantity in terms of planar diagrams of matrix integrals.
Production and phenomenology of glueballs
Chan, Chang S.; Lindenbaum, S.J.
1988-01-01
After a brief introduction, the current status of the prominent glueball candidates are reviewed. In particular, we present a partial wave analysis of 6658 events of the reaction ..pi../sup /minus//p ..-->.. /phi//phi/n at 22 GeV/c. The data analysis reveals three resonances g/sub T/(2010), g/sub T'/(2300) and g/sub T/double prime//(2340), all with the same quantum numbers I/sup G/J/sup PC/ = 0/sup +/2/sup + +/ which comprise virtually all the production cross section. The large /phi//phi/n signal occurs over a mostly structureless and incoherent /phi/K/sup +/K/sup /minus// background. The absence of the expected OZI suppression, and the striking differences of these states from conventional states and background in other channels has so far only been successfully explained by assuming they are produced by 1-3 J/sup PC/ = 2/sup + +/ glueballs (multigluon resonances). The forthcoming search for an exotic J/sup PC/ glueball is also discussed. 20 refs., 15 figs., 1 tab.
Evidence for the observation of a glueball
Weingarten, D
1996-01-01
I briefly review lattice QCD, the valence (quenched) approximation, and the application of both to the determination of the mass and two-body decay couplings of the lightest scalar glueball. Results in agreement with the observed properties of f_J(1710) strongly suggest this resonance is largely a scalar glueball.
Noise reduction algorithm for glueball correlators
Majumdar, Pushan, E-mail: tppm@iacs.res.in [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Kolkata (India); Mathur, Nilmani, E-mail: nilmani@theory.tifr.res.in [Department of Theoretical Physics, Tata Institute of Fundamental Research, Mumbai (India); Mondal, Sourav, E-mail: tpsm5@iacs.res.in [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Kolkata (India)
2014-09-07
We present an error reduction method for obtaining glueball correlators from Monte Carlo simulations of SU(3) lattice gauge theory. We explore the scalar and tensor channels at three different lattice spacings. Using this method we can follow glueball correlators to temporal separations even up to 1 fermi. We estimate the improvement over the naive method and compare our results with existing computations.
Pseudovector mesons, hybrids and glueballs
Burakovsky, L; Burakovsky, Leonid; Page, Philip R.
2000-01-01
We consider glueball- (hybrid) meson mixing for the low-lying four pseudovector states. The h_1'(1380) decays dominantly to K*K with some presence in rho pi and omega eta. The newly observed h_1(1600) has a D- to S-wave width ratio to omega eta which does not enable differentiation between a conventional and hybrid meson interpretation. We predict the decay pattern of the isopartner conventional or hybrid meson b_1(1650). A notably narrow s sbar partner h_1'(1810) is predicted.
Glueball-baryon interactions in holographic QCD
Li, Si-Wen
2017-10-01
Studying the Witten-Sakai-Sugimoto model with type IIA string theory, we find the glueball-baryon interaction is predicted in this model. The glueball is identified as the 11D gravitational waves or graviton described by the M5-brane supergravity solution. Employing the relation of M-theory and type IIA string theory, glueball is also 10D gravitational perturbations which are the excited modes by close strings in the bulk of this model. On the other hand, baryon is identified as a D4-brane wrapped on S4 which is named as baryon vertex, so the glueball-baryon interaction is nothing but the close string/baryon vertex interaction in this model. Since the baryon vertex could be equivalently treated as the instanton configurations on the flavor brane, we identify the glueball-baryon interaction as ;graviton-instanton; interaction in order to describe it quantitatively by the quantum mechanical system for the collective modes of baryons. So the effective Hamiltonian can be obtained by considering the gravitational perturbations in the flavor brane action. With this Hamiltonian, the amplitudes and the selection rules of the glueball-baryon interaction can be analytically calculated in the strong coupling limit. We show our calculations explicitly in two characteristic situations which are ;scalar and tensor glueball interacting with baryons;. Although there is a long way to go, our work provides a holographic way to understand the interactions of baryons in hadronic physics and nuclear physics by the underlying string theory.
Terning, J. (John)
2002-01-01
The author reviews the calculation of the glueball spectrum in non-supersymmetric Yang-Mills theory (in 3 and 4 dimensions) using the conjectured duality between supergravity and large N gauge theories. The glueball masses are obtained by solving the supergravity wave equations in a black hole geometry. The masses obtained this way are in unexpectedly good agreement with the available lattice data, and are much better than strong-coupling expansion results. The author also shows how to use a modified version of the duality to calculate the glueball mass spectrum with some of the Kaluza-Klein states of the supergravity theory decoupled from the spectrum.
Glueball dynamics in the hot plasma
Kochelev, Nikolai [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna, Moscow region (Russian Federation)
2016-07-15
We discuss the glueball contribution to the equation of state (EoS) of hot gluon matter below and above T{sub c}. We show that the strong variation of the masses of the scalar and pseudoscalar glueballs near T{sub c} is determining the thermodynamics of the SU(3) gauge theory. We provide arguments to justify that these glueballs become massless at T{sub G} ∼ 1.1 T{sub c}, a phenomenon which is crucial to understand the mysterious behavior of the trace anomaly found in lattice calculations. (orig.)
A Lattice Study of the Glueball Spectrum
LIU Chuan
2001-01-01
The glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU(3) lattice gauge theory. The smallest spatial lattice spacing is about 0.08 fm which makes the extrapolation to the ontinuum limit more reliable. Converting our lattice results to physical units using the scale set by the static quark potential, we obtain the following results for the glueball masses: MG(0++) -＝ 1730(90) MeV for the scalarglueball and MG(2++) ＝ 2400(95) MeV for the tensor glueball.
Decay modes of the excited pseudoscalar glueball
Eshraim, Walaa I.; Schramm, Stefan
2017-01-01
We study three different chiral Lagrangians that describe the two- and three-body decays of an excited pseudoscalar glueball, JP C=0*-+ , into light mesons and charmonium states as well as into a scalar and pseudoscalar glueball. We compute the decay channels for an excited pseudoscalar glueball with a mass of 3.7 GeV and consider a ground-state pseudoscalar glueball of mass 2.6 GeV, following predictions from lattice QCD simulations. These states and channels are in reach of the ongoing BESIII experiment and the PANDA experiments at the upcoming FAIR facility experiment. We present the resulting decay branching ratios with a parameter-free prediction.
Noise reduction algorithm for glueball correlators
Pushan Majumdar
2014-09-01
Full Text Available We present an error reduction method for obtaining glueball correlators from Monte Carlo simulations of SU(3 lattice gauge theory. We explore the scalar and tensor channels at three different lattice spacings. Using this method we can follow glueball correlators to temporal separations even up to 1 fermi. We estimate the improvement over the naive method and compare our results with existing computations.
Glueball Production via Gluonic Penguin B Decays
He, Xiao-Gang
2015-01-01
We study glueball $G$ production in gluonic penguin decay $B\\to G + X_s$, using the next-to-leading order $b\\to s g^*$ gluonic penguin interaction and effective couplings of a glueball to two perturbative gluons. Subsequent decays of a scalar glueball are described by using techniques of effective chiral Lagrangian to incorporate the interaction between a glueball and pseudoscalar mesons. Mixing effects between the pure glueball with other mesons are considered. Identifying the $f_0(1710)$ to be a scalar glueball, we find that both the top and charm penguin to be important and obtain a sizable branching ratio for $B\\to f_0(1710) + X_s$ of order $1.3\\times 10^{-4} (f/0.07\\mbox{GeV}^{-1})^2$, where the effective coupling strength $f$ is estimated to be $0.07$ GeV$^{-1}$ using experimental data for the branching ratio of $f_0(1710) \\to K \\overline K$ based on chiral Lagrangian estimate. An alternative perturbative QCD based estimation of $f$ is a factor of 20 larger, which would imply a much enhanced branching r...
The Glueball Spectrum In Conventional And Supersymmetric Quantum Chromodynamics
Gabadadze, Gregory T
1998-01-01
In the Dissertation we study some nonperturbative aspects of conventional Quantum Chromodynamics and its minimal supersymmetric counterpart, supersymmetric gluodynamics. After the introduction, the discussion of the spectrum of lightest glueballs in Quantum Chromodynamics is given. It is shown that the pseudoscalar glueball mass in Quantum Chromodynamics is less than the mass obtained in quenched lattice calculations. The glueball mass and nonperturbative glueball matrix elements are calculated. The production rate for the pseudoscalar glueball in radiative decays is predicted. Then, we study the nonperturbative features of the Lagrangian of Quantum Chromodynamics which might be responsible for formation of the pseudoscalar glueball state. The issue of the screening of the topological charge is analyzed. A possible non-perturbative mechanism of formation of the pseudoscalar glueball state is proposed. The masses of lowest pseudoscalar glueballs are predicted within the framework of this approach. The second h...
NEW MESON MASS RELATION AND LOWEST PSEUDOSCALAR GLUEBALL MASS
WU NING; RUAN TU-NAN; ZHENG ZHI-PENG
2001-01-01
After considering its mixing with the glueball, we give a new mass relation for the meson nonet. According to this mass relation and the predicted mass of the pseudoscalar glueball given by lattice calculations and the effective Hamiltonian, the expected mass of the mixed pseudoscalar glueball is about 1.7 GeV. This result is helpful in the experimental search for the mixed isoscalar pseudoscalar glueball. η(1760) is discussed as a possible candidate for this type of particle.
Excited Scalar Mesons and the Search for Glueballs
Parganlija, Denis
2016-01-01
We discuss the importance of mixing between glueballs -- bound states of gluons -- and excited $\\bar{q}q$ states for the glueball search. A preliminary study of the excited states in the Extended Linear Sigma Model (eLSM) suggests their masses in the scalar channel to be in the vicinity of the scalar-glueball mass found in Lattice QCD. This could have implications for future glueball searches.
QCD glueball Regge trajectory and the pomeron
Llanes-Estrada, F J; Ribeiro, J E F; Szczepaniak, Adam P
2002-01-01
Implementing many-body techniques successful in other fields, we report a glueball Regge trajectory emerging from diagonalizing a confining Coulomb gauge Hamiltonian for constituent gluons. Through a BCS vacuum ansatz and gap equation, the dressed gluons acquire a dynamic mass, of order 0.8 GeV, providing the quasiparticle degrees of freedom for a TDA glueball formulation. The TDA eigenstates for two constituent gluons have orbital, L, excitations with a characteristic energy of 0.4 GeV revealing a clear Regge trajectory. In particular, the J sup P sup C =2 sup + sup + glueball coincides with the pomeron given by alpha sub P (t)=1.08+(0.25 GeV sup - sup 2)t. We also ascertain that lattice data supports our result. Finally, we conjecture on the odderon puzzle.
String theory and the dark glueball problem
Halverson, James; Nelson, Brent D.; Ruehle, Fabian
2017-02-01
We study cosmological constraints on dark pure Yang-Mills sectors. Dark glueballs are overproduced for large regions of ultraviolet parameter space. The problem may be alleviated in two ways: via a large preferential reheating into the visible sector, motivating certain inflation or modulus decay models, or via decays into axions or moduli, which are strongly constrained by nucleosynthesis and Δ Neff bounds. String models frequently have multiple hidden Yang-Mills sectors, which are subject to even stronger constraints due to the existence of multiple dark glueballs.
Top-down Holographic Glueball Decay Rates
Brünner, F; Rebhan, A
2015-01-01
We present new results on the decay patterns of scalar and tensor glueballs in the top-down holographic Witten-Sakai-Sugimoto model. This model, which has only one free dimensionless parameter, gives semi-quantitative predictions for the vector meson spectrum, their decay widths, and also a gluon condensate in agreement with SVZ sum rules. The holographic predictions for scalar glueball decay rates are compared with experimental data for the widely discussed gluon candidates f0(1500) and f0(1710).
Composite Inflation Setup and Glueball Inflation
Bezrukov, Fedor; Channuie, Phongpichit; Jark Joergensen, Jakob
2012-01-01
the relevant example where the inflaton is identified with the glueball field of a pure Yang-Mills theory. We introduce the dilatonic-like glueball action which is obtained by requiring saturation of the underlying Yang-Mills trace anomaly at the effective action level. We couple the resulting action non......-minimally to gravity. We demonstrate that it is possible to achieve successful inflation with the confining scale of the underlying Yang-Mills theory naturally of the order of the grand unified energy scale. We also argue that within the metric formulation models of composite inflation lead to a more consistent...
String Theory and the Dark Glueball Problem
Halverson, James; Ruehle, Fabian
2016-01-01
We study cosmological constraints on dark pure Yang-Mills sectors. Dark glueballs are overproduced for large regions of ultraviolet parameter space. The problem may be alleviated in two ways: via a large preferential reheating into the visible sector, motivating certain inflation or modulus decay models, or via decays into axions or moduli, which are strongly constrained by nucleosynthesis and $\\Delta N_{\\text{eff}}$ bounds. String models frequently have multiple hidden Yang-Mills sectors, which are subject to even stronger constraints due to the existence of multiple dark glueballs.
Glueball Masses from Linearly Confining Supergravity
Hailu, Girma
2012-01-01
Mass spectrum of 0++ glueballs is produced using a dual supergravity theory we proposed for pure N=1 SU(N) gauge theory in four dimensions in the large N limit in the IR. The glueball states are expressed in terms of Whittaker functions. The spectrum is discrete and a function whose roots give the masses is written. The ratios of the masses are independent of the parameters of the theory and comparison to recent non-supersymmetric large N lattice QCD data available for the lowest three states shows agreement to within five percent.
Toward a Gravity Dual of Glueball Inflation
Anguelova, Lilia; Wijewardhana, L C Rohana
2015-01-01
We summarize and extend our work on nonsupersymmetric solutions of a 5d consistent truncation of type IIB supergravity, that is relevant for gauge/gravity duality. The fields in this 5d theory are the five-dimensional metric and a set of scalars. We find solutions of the 5d equations of motion, which represent dS_4 foliations over the fifth (radial) dimension. In each solution at least one scalar has a nontrivial radial profile. These scalars are interpreted as glueballs in the dual gauge theory, living in 4d de Sitter space. We explain why this lays a foundation for building gravity duals of glueball inflation models.
Pomeron as a Reggeized Tensor Glueball
MA Wei-Xing; A.W.Thomas; SHEN Peng-Nian; ZHOU Li-Juan
2001-01-01
We study gluonic content of the pomeron and propose that the pomeron could be a reggeized tensor glueball ζ(2230) with quantum numbers IG JPc = 0+2++.This conjecture is examined in high energy proton-proton elastic scattering,and the calculations lend a favorable support to our physical idea.``
Glueball decay patterns in top-down holographic QCD
Brünner, Frederic; Rebhan, Anton
2015-01-01
We discuss our results on scalar glueball decay in the top-down holographic Witten-Sakai-Sugimoto model for low-energy QCD and compare with available experimental data, which appear to disfavor the glueball candidate $f_0(1500)$ but seem to be perfectly consistent with interpreting $f_0(1710)$ as a nearly unmixed glueball. The holographic model moreover makes definite predictions for future experiments.
Two-gluon and trigluon glueballs from dynamical holography QCD
Chen, Yi-dian; Huang, Mei
2016-12-01
We study the scalar, vector and tensor two-gluon and trigluon glueball spectra in the framework of the 5-dimension dynamical holographic QCD model, where the metric structure is deformed self-consistently by the dilaton field. For comparison, the glueball spectra are also calculated in the hard-wall and soft-wall holographic QCD models. In order to distinguish glueballs with even and odd parities, we introduce a positive and negative coupling between the dilaton field and glueballs, and for higher spin glueballs, we introduce a deformed 5-dimension mass. With this set-up, there is only one free parameter from the quadratic dilaton profile in the dynamical holographic QCD model, which is fixed by the scalar glueball spectra. It is found that the two-gluon glueball spectra produced in the dynamical holographic QCD model are in good agreement with lattice data. Among six trigluon glueballs, the produced masses for 1±- and 2-- are in good agreement with lattice data, and the produced masses for 0--, 0+- and 2+- are around 1.5 GeV lighter than lattice results. This result might indicate that the three trigluon glueballs of 0--, 0+- and 2+- are dominated by the three-gluon condensate contribution. Supported by the NSFC (11175251, 11621131001), DFG and NSFC (CRC 110), CAS Key Project KJCX2-EW-N01, K.C.Wong Education Foundation, and Youth Innovation Promotion Association of CAS
QCD Glueball Regge Trajectories and the Pomeron
Llanes-Estrada, F J; De Bicudo, P J A; Tavares-Ribeiro, J E F; Szczepaniak, A P; Llanes-Estrada, Felipe J.; Cotanch, Stephen R; Bicudo, Pedro J A; Szczepaniak, Adam P
2000-01-01
We report glueball Regge trajectories emerging from diagonalizing a confining Coulomb gauge Hamiltonian for constituent gluons. Using a BCS vacuum ansatz and gap equation, the dressed gluons acquire a mass, of order 800 MeV, providing the quasiparticle degrees of freedom for a TDA glueball formulation. The TDA eigenstates for two constituent gluons have orbital, L, excitations with a characteristic energy of 400 MeV and reveal clear Regge trajectories for each L and S combination giving J=L+S... |L-S|, where S is the total (sum) gluon spin. Significantly, all trajectories have the same 0.28 GeV-2 Regge slope, similar to the pomeron value of 0.25 GeV-2. Recent lattice data further supports this result and yields an intercept close to the pomeron.
Exclusive glueball production at the LHC
Machado, M V T
2011-01-01
In this contribution we summarize recent results on the computation of cross sections for glueball candidates production in quasi-real photon-photon collisions and on central diffraction processes, i.e. double Pomeron exchange, in heavy ion interactions at the LHC are computed. In particular, we provide predictions for the production of exotic mesons f0(1500), f0(1710) and X(1835). The rates for these distinct production channels are compared.
QCD, OZI, and evidence for glueballs
Lindenbaum, S.J.
1981-01-01
The characteristics expected from low Q-QCD for the behavior of glueballs and the OZI rule is discussed. The reaction ..pi../sup -/p ..-->.. phi phi n represents on OZI forbidden (hairpin) diagram. It has been observed at the Brookhaven National Laboratory multiparticle spectrometer by the Brookhaven National Laboratory/City College of New York group. The author has shown that the expected OZI suppression is essentially entirely absent and in fact the Isobar Model which does not contain OZI suppression quantitatively explains the observed results. A general evaluation of the special characteristics of the data compared to other related reactions plus the foregoing facts leads the author to conclude that the intervention of glueball resonances is the likely explanation in the context of QCD. Other explanations are shown to be improbable. In particular the hypothesis that decay of a radial excitation of the eta' is responsible for lack of OZI suppression is ruled out. Planned experiments with the purpose of explicity discovering glueballs will be discussed. The OZI rule peculiarities such as violation of crossing symmetry and unitarity are attributed to color confinement.
Exclusive glueball production in high energy nucleus-nucleus collisions
Machado, M V T
2010-01-01
The cross sections for the glueball candidates production in quasi-real photon-photon collisions and on central diffraction processes, i.e. double Pomeron exchange, in heavy ion interactions at RHIC and LHC are computed. The rates for these distinct production channels are compared and they may be a fruitful approach to the investigation of glueballs.
Monte Carlo Simulation on Glueball Search at BESⅢ
QIN Hu; SHEN Xiao-Yan
2007-01-01
The J/ψ radiative decays are suggested as promising modes for glueball search. A full Monte Carlo simulation of J/ψ→γηη and γηη', based on the design of BESⅢ detector, is performed to study the sensitivity of searching for a possible tensor glueball at BESⅢ.
Factorization for radiative heavy quarkonium decays into scalar Glueball
Zhu, Ruilin [INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology,Department of Physics and Astronomy, Shanghai Jiao Tong University,Dongchuan RD 800, Shanghai 200240 (China); State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Sciences,Zhongguancun E. St. 55, Beijing 100190 (China); CAS Center for Excellence in Particle Physics,Institute of High Energy Physics, Chinese Academy of Sciences,Yuquan RD 19B, Beijing 100049 (China)
2015-09-24
We establish the factorization formula for scalar Glueball production through radiative decays of vector states of heavy quarkonia, e.g. J/ψ, ψ(2S) and Υ(nS), where the Glueball mass is much less than the parent heavy quarkonium mass. The factorization is demonstrated explicitly at one-loop level through the next-to-leading order (NLO) corrections to the hard kernel, the non-relativistic QCD (NRQCD) long-distance matrix elements (LDMEs) of the heavy quarkonium, and the light-cone distribution amplitude (LCDA) of scalar Glueball. The factorization provides a comprehensive theoretical approach to investigate Glueball production in the radiative decays of vector states of heavy quarkonia and determine the physic nature of Glueball. We discuss the scale evolution equation of LCDA for scalar Glueball. In the end, we extract the value of the decay constant of Scalar Glueball from Lattice QCD calculation and analyze the mixing effect among f{sub 0}(1370), f{sub 0}(1500) and f{sub 0}(1710).
Holographic QCD predictions for production and decay of pseudoscalar glueballs
Brünner, Frederic
2016-01-01
The top-down holographic Witten-Sakai-Sugimoto model for low-energy QCD, augmented by finite quark masses, has recently been found to be able to reproduce the decay pattern of the scalar glueball candidate f0(1710) on a quantitative level. In this Letter we show that this model predicts a narrow pseudoscalar glueball heavier than the scalar glueball and with a very restricted decay pattern involving eta or eta' mesons. Production should be either in pairs or in association with eta(') mesons. We discuss the prospect of discovery in high-energy hadron collider experiments through central exclusive production by comparing with eta' pair production.
Hadronic production of J/sup PC/ = 2/sup + +/ glueballs
Lindenbaum, S.J.
1986-03-17
An OZI suppressed channel with variable mass, namely the reaction ..pi../sup -/p ..-->.. phi phi n, has been used as a filter which allows resonating gluons or glueballs to pass, while strongly rejecting conventional quark-built hadronic states. The breakdown of the OZI suppression signals a glueball. Glueball mass and particle width estimates are discussed. Reasons why g/sub T/'s have not been seen in other channels, particularly the decay of J/psi, are considered. 34 refs., 9 figs. (LEW)
Glueball-Quarkonium Mixing in the Quark and Chromon Model
Zhang, Pengming; Xie, Ju-Jun; Yoon, J H; Cho, Y M
2016-01-01
The Abelian decomposition of QCD which decomposes the gluons to the color neutral binding gluons (the neurons) and the colored valence gluons (the chromons) gauge independently naturally generalizes the quark model to the quark and chromon model which can play the central role in hadron spectroscopy. We discuss how the quark and chromon model describes the glueballs and the glueball-quarkonium mixing in QCD. We present the numerical analysis of glueball-quarkonium mixing in $0^{++}$, $2^{++}$, and $0^{-+}$ sectors below 2 GeV, and show that in the $0^{++}$ sector $f_0(500)$ and $f_0(1500)$, in the $2^{++}$ sector $f_2(1950)$, and in the $0^{-+}$ sector $\\eta(1405)$ and $\\eta(1475)$ could be identified as predominantly the glueball states. We discuss the physical implications of our result.
Review of meson spectroscopy: quark states and glueballs
Chanowitz, M.S.
1981-11-01
A group of three lectures on hadron spectroscopy are presented. Topics covered include: light L = 0 mesons, light L = 1 mesons, antiquark antiquark quark quark exotics, a catalogue of higher quark antiquark excitations, heavy quarkonium, and glueballs. (GHT)
Scalar model of glueball in nonperturbative quantisation \\`a la Heisenberg
Dzhunushaliev, Vladimir
2015-01-01
A scalar model of glueball is considered. The model is based on two scalar fields approximation for SU(3) non-Abelian Lagrangian. The approach to approximation makes use of the assumption that 2 and 4-points Green's functions are described in terms of some two scalar fields. The model is described via non-perturbative method due to value of coupling constant, which does not permit us using of Feynman diagrams and therefore of perturbative methods. Asymptotical behaviour of the scalar fields are obtained. Profiles of these fileds calculated for a range of values of a parameter of the problem is given. Detailed numerical investigation of corresponding equations describing this model is performed. The dependence of the glueball mass vs parameters of scalar fields is shown. Comparison of characteristics of glueball obtained in our two-scalar model and predictions of other models and experimental data for glueball is performed.
Glueball Spectrum and Matrix Elements on Anisotropic Lattices
Y. Chen; A. Alexandru; S.J. Dong; T. Draper; I. Horvath; F.X. Lee; K.F. Liu; N. Mathur; C. Morningstar; M. Peardon; S. Tamhankar; B.L. Young; J.B. Zhang
2006-01-01
The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing ranging from 0.1fm - 0.2fm. These matrix elements are needed to predict the glueball branching ratios in J/{psi} radiative decays which will help identify the glueball states in experiments. Two types of improved local gluonic operators are constructed for a self-consistent check and the finite volume effects are studied. We find that lattice spacing dependence of our results is very weak and the continuum limits are reliably extrapolated, as a result of improvement of the lattice gauge action and local operators. We also give updated glueball masses with various quantum numbers.
Glueball calculations in large-$N_{c}$ gauge theory
Dalley, S
1999-01-01
We use the light-front Hamiltonian of transverse lattice gauge theory to compute from first principles the glueball spectrum and light-front wavefunctions in the leading order of the 1/N_c colour expansion. We find 0^{++}, 2^{++}, and 1^{+-} glueballs having masses consistent with N_c=3 data available from Euclidean lattice path integral methods. The wavefunctions exhibit a light-front constituent gluon structure.
Glueball and meson spectrum in large-N massless QCD
Bochicchio, Marco
2013-01-01
We provide outstanding numerical evidence that in large-N massless QCD the joint spectrum of the masses squared, for fixed integer spin s and unspecified parity and charge conjugation, obeys exactly the following laws: m_k^2 = (k+s/2) Lambda_QCD^2 for s even, m_k^2 = 2(k+s/2) Lambda_QCD^2 for s odd, k = 1,2,... for glueballs, and m_n^2 = 1/2 (n+s/2) Lambda_QCD^2, n = 0,1,... for mesons. One of the striking features of these laws is that they imply that the glueball and meson masses squared form exactly-linear Regge trajectories in the large-N limit of massless QCD, all the way down to the low-lying states: A fact unsuspected so far. The numerical evidence is based on lattice computations by Meyer-Teper in SU(8) YM for glueballs, and by Bali et al. in SU(17) quenched massless QCD for mesons, that we analyze systematically. The aforementioned spectrum for spin-0 glueballs is implied by a Topological Field Theory underlying the large-N limit of YM, whose glueball propagators satisfy as well fundamental universal...
Nonchiral enhancement of scalar glueball decay in the Witten-Sakai-Sugimoto model
Brünner, Frederic
2015-01-01
We estimate the consequences of finite masses of pseudoscalar mesons on the decay rates of scalar glueballs in the Witten-Sakai-Sugimoto model, a top-down holographic model of low-energy QCD, by extrapolating from the calculable vertex of glueball fields and the eta' meson which follows from the Witten-Veneziano mechanism for giving mass to the latter. Evaluating the effect on the recently calculated decay rates of glueballs in the Witten-Sakai-Sugimoto model, we find a strong enhancement of the decay of scalar glueballs into kaons and eta mesons, in fairly close agreement with experimental data on the glueball candidate f0(1710).
Pseudoscalar glueball mass from $\\eta$-$\\eta'$-$G$ mixing
Cheng, Hai-Yang; Liu, Keh-Fei
2008-01-01
We deduce the mass of the pseudoscalar glueball $G$ from an $\\eta$-$\\eta'$-$G$ mixing formalism based on the anomalous Ward identity for transition matrix elements. With the inputs from the recent KLOE experiment, we find a solution for the pseudoscalar glueball mass around $(1.4\\pm 0.1)$ GeV, which is fairly insensitive to a range of inputs with or without Okubo-Zweig-Iizuka-rule violating effects. This affirms that $\\eta(1405)$, having a large production rate in the radiative $J/\\Psi$ decay and not seen in $\\gamma\\gamma$ reactions, is indeed a leading candidate for the pseudoscalar glueball. Other relevant quantities including the anomaly and pseudoscalar density matrix elements are obtained. The decay widths for $G\\to \\gamma\\gamma$, $\\ell^+\\ell^-$ are also predicted.
Direct instantons, topological charge screening and QCD glueball sum rules
Forkel, H
2003-01-01
Nonperturbative Wilson coefficients of the operator product expansion (OPE) for the spin-0 glueball correlators are derived and analyzed. A systematic treatment of the direct instanton contributions is given, based on realistic instanton size distributions and renormalization at the operator scale. In the pseudoscalar channel, topological charge screening is identified as an additional source of (semi-) hard nonperturbative physics. The screening contributions are shown to be vital for consistency with the anomalous axial Ward identity, and previously encountered pathologies (positivity violations and the disappearance of the 0^{-+} glueball signal) are traced to their neglect. On the basis of the extended OPE, a comprehensive quantitative analysis of eight Borel-moment sum rules in both spin-0 glueball channels is then performed. The nonperturbative OPE coefficients turn out to be indispensable for consistent sum rules and for their reconciliation with the underlying low-energy theorems. The topological shor...
Glueballs Mass Spectrum in an Inflationary Braneworld Scenario
Barosi, L; Jesuino, H S; Queiroz, A R
2010-01-01
We address the issue of glueball masses in a holographic dual field theory on the boundary of an AdS space deformed by a four-dimensional cosmological constant. These glueballs are related to scalar and tensorial fluctuations of the bulk fields on this space. In the Euclidean AdS4 case the allowed masses are discretized and are related to distinct inflaton masses on a 3-brane with several states of inflation. We then obtain the e-folds number in terms of the glueball masses. In the last part we focus on the Lorentzian dS4 case to focus on the QCD equation of state in dual field theory.
Scalar mesons and the search for the 0{sup ++} glueball
Thoma, U. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
2003-11-01
The possibility that gluonic excitations of hadronic matter or of the QCD vacuum may exist is perhaps one of the most fascinating topics in hadron spectroscopy. Glueballs are predicted by many models; in particular, present-day lattice gauge calculations require their existence. All these models agree that the lightest glueball should have scalar quantum numbers and a mass around 1.6GeV, which corresponds to the mass region where the scalar q anti q-mesons are expected. Therefore, mixing effects can complicate the search for the glueball. Experiments indeed show an overpopulation of states, for which many different interpretations exist. This reflects the complexity of the situation. New data from various experiments on scalar states give hints toward an interpretation of the scalar states. But still many questions remain. (orig.)
Scalar mesons and the search for the 0{sup ++} Glueball
Ulrike Thoma
2002-10-01
The possibility that gluonic excitations of hadronic matter or of the QCD vacuum may exist is perhaps one of the most fascinating topics in hadron spectroscopy. Glueballs are predicted by many models; in particular present-day lattice gauge calculations require their existence. All these models agree that the lightest glueball should have scalar quantum numbers and a mass around 1.6 GeV, which corresponds to the mass region where the scalar qq[bar]-mesons are expected. Therefore mixing effects can complicate the search for the glueball. Experiments indeed show an overpopulation of states, for which many different interpretations exist. This reflects the complexity of the situation. New data from various experiments on scalar states give hints toward an interpretation of the scalar states. But, still many questions remain.
Gravitational Waves From SU(N) Glueball Dark Matter
Soni, Amarjit
2016-01-01
A hidden sector with pure non-abelian gauge symmetry is an elegant and just about the simplest model of dark matter. In this model the dark matter candidate is the lightest bound state made of the confined gauge fields, the dark glueball. In spite of its simplicity, the model has been shown to have several interesting non-standard implications in cosmology. In this work, we explore the gravitational waves from binary boson stars made of self-gravitating dark glueball fields as a natural and important consequence. We derive the dark SU($N$) star mass and radius as functions of the only two fundamental parameters in the model, the glueball mass $m$ and the number of colors $N$, and identify the regions that could be probed by the LIGO and future gravitational wave observatories.
Scattering of Glueballs and the AdS/CFT Correspondence
Filho, H B; Filho, Henrique Boschi; Braga, Nelson R. F.
2004-01-01
Inspired in the AdS/CFT correspondence one can look for dualities between string theory and non conformal field theories. Exact dualities in the non conformal case are intricate but approximations can be helpful in extracting physical results. A phenomenological approach consists in introducing a scale corresponding to the maximum value of the axial AdS coordinate. Here we show that this approach can reproduce the scaling of high energy glueball scattering amplitudes and also an approximation for the scalar glueball mass ratios.
Glueball Decay Rates in the Witten-Sakai-Sugimoto Model
Brünner, Frederic; Rebhan, Anton
2015-01-01
We revisit and extend previous calculations of glueball decay rates in the Sakai-Sugimoto model, a holographic top-down approach for QCD with chiral quarks based on D8 probe branes in Witten's holographic model of nonsupersymmetric Yang-Mills theory. The rates for decays into two pions, two vector mesons, four pions, and the strongly suppressed decay into four pi0 are worked out quantitatively, using a range of the 't Hooft coupling which closely reproduces the decay rate of rho and omega mesons and also leads to a gluon condensate consistent with QCD sum rule calculations. The lowest holographic glueball, which arises from a rather exotic polarization of gravitons in the supergravity background, turns out to have a significantly lower mass and larger width than the two widely discussed glueball candidates f0(1500) and f0(1710). The lowest nonexotic and predominantly dilatonic scalar mode, which has a mass of 1487 MeV in the Witten-Sakai-Sugimoto model, instead provides a narrow glueball state, and we conject...
Glueball dark matter in non-standard cosmologies
Acharya, Bobby S.; Fairbairn, Malcolm; Hardy, Edward
2017-07-01
Hidden sector glueball dark matter is well motivated by string theory, compactifications of which often have extra gauge groups uncoupled to the visible sector. We study the dynamics of glueballs in theories with a period of late time primordial matter domination followed by a low final reheating temperature due to a gravitationally coupled modulus. Compared to scenarios with a high reheating temperature, the required relic abundance is possible with higher hidden sector confinement scales, and less extreme differences in the entropy densities of the hidden and visible sectors. Both of these can occur in string derived models, and relatively light moduli are helpful for obtaining viable phenomenology. We also study the effects of hidden sector gluinos. In some parts of parameter space these can be the dominant dark matter component, while in others their abundance is much smaller than that of glueballs. Finally, we show that heavy glueballs produced from energy in the hidden sector prior to matter domination can have the correct relic abundance if they are sufficiently long lived.
A kinematical selection of glueball candidates in central production
Barberis, D; Binon, Freddy G; Carney, J N; Close, Francis Edwin; Danielsen, K M; Dolgopolov, A V; Donskov, S V; Earl, B C; Evans, D; French, Bernard R; Inaba, S; Inyakin, A V; Jacholkowski, A; Jacobsen, T; Khaustov, G V; Kinashi, T; Kinson, J B; Kirk, A; Klempt, W; Kobayashi, M; Kondashov, A A; Kulchitskii, Yu A; Lednev, A A; Lenti, V; Maljukov, S; Martinengo, P; Minashvili, I A; Myklebost, K; Nakagawa, T; Norman, K L; Olsen, J M; Peigneux, J P; Polovnikov, S A; Polyakov, V A; Prokoshkin, Yu D; Romanovsky, V I; Rotscheidt, Herbert; Rumyantsev, V; Rusakovitch, N A; Sadovsky, S A; Samoylenko, V D; Semenov, A A; Sené, M; Sené, R; Shagin, P M; Shimizu, H M; Singovsky, A V; Soloviev, A S; Stassinaki, M; Stroot, Jean-Pierre; Sugonyaev, V P; Takamatsu, K; Tchlatchidze, G A; Tsuru, T; Vasileiadis, G; Venables, M; Villalobos Baillie, O; Votruba, M F; Yasu, Y
1997-01-01
A study of central meson production as a function of the difference in transverse momentum ($dP_T$) of the exchanged particles shows that undisputed $q \\overline q$ mesons are suppressed at small $dP_T$ whereas the glueball candidates are enhanced.
Scalar Glueballs A Gaussian Sum-rules Analysis
Harnett, D
2002-01-01
Although marginally more complicated than the traditional laplace sum-rules, gaussian sum-rules have the advantage of being able to probe excited and ground hadronic states with similar sensitivity. Gaussian sum-rule analysis techniques are applied to the problematic scalar glueball channel to determine masses, widths, and relative resonance strengths of low-lying scalar glueball states contributing to the hadronic spectral function. An important feature of our analysis is the inclusion of instanton contributions to the scalar gluonic correlation function. Compared with the next-to-leading gaussian sum- rule, the analysis of the lowest weighted sum-rule (which contains a large scale independent contribution from the low energy theorem) is shown to be unreliable because of instability under QCD uncertainties. However, the presence of instanton effects leads to approximately consistent mass scales in the lowest weighted and next- lowest weighted sum-rules. The analysis of the next-to- leading sum-rule demonstra...
Sphaleron glueballs in NBI theory with symmetrized trace
Dyadichev, V V
2000-01-01
We derive a closed expression for the SU(2) Born-Infeld action with the symmetrized trace for static spherically symmetric purely magnetic configurations. The lagrangian is obtained in terms of elementary functions. Using it, we investigate glueball solutions to the flat space NBI theory and their self-gravitating counterparts. Such solutions, found previously in the NBI model with the 'square root - ordinary trace' lagrangian, are shown to persist in the theory with the symmetrized trace lagrangian as well. Although the symmetrized trace NBI equations differ substantially from those of the theory with the ordinary trace, a qualitative picture of glueballs remains essentially the same. Gravity further reduces the difference between solutions in these two models, and, for sufficiently large values of the effective gravitational coupling, solutions tends to the same limiting form. The black holes in the NBI theory with the symmetrized trace are also discussed.
Scalar model of SU(N) glueball \\`a la Heisenberg
Dzhunushaliev, Vladimir
2016-01-01
Nonperturbative model of glueball is studied. The model is based on the nonperturbative quantization technique suggested by Heisenberg. 2- and 4-point Green functions for a gauge potential are expressed in terms of two scalar fields. The first scalar field describes quantum fluctuations of a subgroup $SU(n) \\subset SU(N)$, and the second one describes quantum fluctuations of coset $SU(N) / SU(n)$. An effective Lagrangian for the scalar fields is obtained. The coefficients for all terms in the Lagrangian are calculated, and it is shown that they depend on $\\dim SU(n), \\dim SU(N)$. It is demonstrated that spherically symmetric solution describing the glueball does exist.
Large N Scalars: From Glueballs to Dynamical Higgs Models
Sannino, Francesco
2015-01-01
We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective Lagrangian description. The framework allows for systematic investigations of composite dynamics of non-Goldstone nature. Relevant examples are the lightest glueball states emerging in any Yang-Mills theory. We further apply the effective approach and associated counting scheme to composite models at the electroweak scale. To illustrate the formalism we consider the possibility that the Higgs emerges as: the lightest glueball of a new composite theory; the large N scalar meson in models of dynamical electroweak symmetry breaking; the large N pseudodilaton useful also for models of near-conformal dynamics. For each of these realisations we determine the leading N corrections to the electroweak precision parameters. ...
CERN Summer Student Project: Central Exclusive Diffraction and Glueball Searches
van Beest, Marieke
2016-01-01
CERN Summer Student work project report on work conducted in the Diffraction group at the ALICE experiment as well as the obtained results. These include a kinematical calculation with respect to a generic central exclusive process, the selection rules for a centrally produced system with respect to a specific central exclusive diffraction process, and finally a case study of one of the first contributions to the search for glueballs at CERN.
Classical glueballs in non-Abelian Born-Infeld theory
Galtsov, D V; Gal'tsov, Dmitri; Kerner, Richard
2000-01-01
It is shown that the Born-Infeld-type modification of the quadratic Yang-Mills action suggested by the superstring theory gives rise to classical particle-like solutions prohibited in the standard Yang-Mills theory. This becomes possible due to the scale invariance breaking by the Born-Infeld non-linearity. New classical glueballs are sphaleronic in nature and exhibit a striking similarity with the Bartnik-McKinnon solutions of the Yang-Mills theory coupled to gravity.
Yang--Mills Glueballs as Closed Bosonic Strings
Dubovsky, Sergei
2016-01-01
We put forward the Axionic String Ansatz (ASA), which provides a unified description for the worldsheet dynamics of confining strings in pure Yang--Mills theory both in $D=3$ and $D=4$ space-time dimensions. The ASA is motivated by the excitation spectrum of long confining strings, as measured on a lattice, and by recently constructed integrable axionic non-critical string models. According to the ASA, pure gluodynamics in 3D is described by a non-critical bosonic string theory without any extra local worldsheet degrees of freedom. We argue that this assumption fixes the set of quantum numbers (spins, $P$- and $C$-parities) of almost all glueball states. We confront the resulting predictions with the properties of approximately $1^2+2^2+3^2+5^2=39$ lightest glueball states measured on a lattice and find a good agreement. On the other hand, the spectrum of low lying glueballs in 4D gluodynamics suggests the presence of a massive pseudoscalar mode on the string worldsheet, in agreement with the ASA and lattice ...
Yang-Mills glueballs as closed bosonic strings
Dubovsky, Sergei; Hernández-Chifflet, Guzmán
2017-02-01
We put forward the Axionic String Ansatz (ASA), which provides a unified description for the worldsheet dynamics of confining strings in pure Yang-Mills theory both in D = 3 and D = 4 space-time dimensions. The ASA is motivated by the excitation spectrum of long confining strings, as measured on a lattice, and by recently constructed integrable axionic non-critical string models. According to the ASA, pure gluodynamics in 3D is described by a non-critical bosonic string theory without any extra local worldsheet degrees of freedom. We argue that this assumption fixes the set of quantum numbers (spins, P-and C-parities) of almost all glueball states. We confront the resulting predictions with the properties of approximately 12 + 22 + 32 + 52 = 39 lightest glueball states measured on a lattice and find a good agreement. On the other hand, the spectrum of low lying glueballs in 4D gluodynamics suggests the presence of a massive pseudoscalar mode on the string worldsheet, in agreement with the ASA and lattice data for long strings.
Some Comments on the Frame of Regge Phenomenology and the Glueball Production Mechanism
PENG Hong-An; XU Jia-Sheng
2000-01-01
We enumerate the limitations in the frame of Regge phenomenology and demonstrate that it should be extended to cover the freedom of constituent gluon, We declare that glueballs are the bound states of constituent gluons.Based on these observations we discuss the glueball production mechanism and the structure of Pomeron.
Scalar Glueball-qqbar Mixing above 1 GeV and implications for Lattice QCD
Close, Francis Edwin
2001-01-01
Lattice QCD predictions have motivated several recent studies of the mixing between the predicted JPC = 0++ glueball and a qqbar nonet in the 1.3 to 1.7 GeV region. We show that results from apparently different approaches have some common features, explain why this is so and abstract general conclusions. We place particular emphasis on the flavour dependent constraints imposed by decays of the f0(1370), f0(1500) and f0(1700) to all pairs of pseudoscalar mesons. From these results we identify a systematic correlation between glueball mass, mixing, and flavour symmetry breaking and conclude that the glueball may be rather lighter than some quenched lattice QCD computations have suggested. We identify experimental tests that can determine the dynamics of a glueball in this mass region and discuss quantitatively the feasibility of decoding glueball-qqbar mixing.
On Slow-roll Glueball Inflation from Holography
Anguelova, Lilia
2016-01-01
We investigate glueball inflation model-building via the methods of the gauge/gravity duality. For that purpose, we consider a certain 5d consistent truncation of type IIB supergravity. This theory admits a solution, whose metric is of the form of a $dS_4$ fibration over a fifth dimension. We find a new time-dependent deformation around this solution, which allows for a small $\\eta$ parameter of the corresponding inflationary model. This resolves a problem with a previous solution that allowed only $\\eta$ of order one and thus gave only an ultra-slow roll regime, but not regular slow roll.
Glueball Decay in the Witten-Sakai-Sugimoto Model and Finite Quark Masses
Brünner, Frederic
2015-01-01
We discuss recent results on the calculation of glueball decay rates in the Witten-Sakai-Sugimoto model, which favor the $f_0(1710)$ meson as a glueball candidate. The flavor asymmetric decay of $f_0(1710)$ is frequently attributed to a putative chiral suppression in glueball decays, which is however questionable in view of the large constituent quark masses induced by chiral symmetry breaking. We find that this can be explained by what we call nonchiral enhancement when finite quark masses are included in the holographic model, with good quantitative agreement with experimental data for $f_0(1710)$. Assuming the latter to indeed be a nearly pure glueball, the model makes essentially parameter-free and thus falsifiable predictions for its decay rates involving vector mesons and an upper limit on the $\\eta\\eta'$ decay rate.
Decay of charmonium states into a scalar and a pseudoscalar glueball
Eshraim Walaa I.
2016-01-01
Full Text Available In the framework of a chiral symmetric model, we expand a U(4R × U(4L symmetric linear sigma model with (axial-vector mesons by including a dilaton field, a scalar glueball, and the pseudoscalar glueball. We compute the decay width of the scalar charmonium state χC0(IP into a predominantly scalar glueball f0(1710. We calculate the decay width of the pseudoscalar charmonium states ηC(IS into a predominantly scalar glueball f0(1710 as well as into a pseudoscalar glueball with a mass of 2.6 GeV (as predicted by Lattice-QCD simulations and with a mass of 2.37 GeV (corresponding to the mass of the resonance X(2370. This study is interesting for the upcoming PANDA experiment at the FAIR facility and BESIII experiment. Moreover, we obtain the mixing angle between a pseudoscalar glueball, with a mass of 2.6 GeV, and the charmonium state ηC.
Decay of charmonium states into a scalar and a pseudoscalar glueball
Eshraim, Walaa I.
2016-11-01
In the framework of a chiral symmetric model, we expand a U(4)R × U(4)L symmetric linear sigma model with (axial-)vector mesons by including a dilaton field, a scalar glueball, and the pseudoscalar glueball. We compute the decay width of the scalar charmonium state χC0(IP) into a predominantly scalar glueball f0(1710). We calculate the decay width of the pseudoscalar charmonium states ηC(IS) into a predominantly scalar glueball f0(1710) as well as into a pseudoscalar glueball with a mass of 2.6 GeV (as predicted by Lattice-QCD simulations) and with a mass of 2.37 GeV (corresponding to the mass of the resonance X(2370)). This study is interesting for the upcoming PANDA experiment at the FAIR facility and BESIII experiment. Moreover, we obtain the mixing angle between a pseudoscalar glueball, with a mass of 2.6 GeV, and the charmonium state ηC.
Capossoli, Eduardo Folco
2016-01-01
In this work, adopting a $5-$dimensional mass renormalisation within a modified holographic softwall model, we calculate analytically the masses of the scalar glueball with its radial excitations and of higher even glueball spin states, with $P=C=+1$. Using this approach we achieved a unified treatment for both scalar and high even spin glueballs. Furthermore, we also obtain the Regge trajectory associated with the pomeron compatible with other approaches.
Mass Spectra of $0^{+-}$, $1^{-+}$, and $2^{+-}$ Exotic Glueballs
Qiao, Cong-Feng
2015-01-01
With appropriate interpolating currents the mass spectra of $0^{+-}$, $1^{-+}$, and $2^{+-}$ oddballs are studied in the framework of QCD sum rules (QCDSR). We find there exits a stable $0^{+-}$ oddball with mass of $4.57 \\pm 0.13 \\, \\text{GeV}$, and three stable $2^{+-}$ oddballs with masses of $2.77 \\pm 0.11$, $4.41 \\pm 0.13$, and $4.99 \\pm 0.14 \\, \\text{GeV}$, whereas, no stable $1^{-+}$ oddball shows up. The possible production and decay modes of these glueballs with unconventional quantum numbers are analyzed, which are hopefully measurable in either BESIII, BELLEII, PANDA, Super-B or LHCb experiments.
Phenomenology of pseudotensor mesons and the pseudotensor glueball
Koenigstein, Adrian [Johann Wolfgang Goethe University, Institute for Theoretical Physics, Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Giacosa, Francesco [Jan Kochanowski University, Institute of Physics, Kielce (Poland); Johann Wolfgang Goethe University, Institute for Theoretical Physics, Frankfurt am Main (Germany)
2016-12-15
We study the decays of the pseudotensor mesons (π{sub 2}(1670), K{sub 2}(1770), η{sub 2}(1645), η{sub 2}(1870)) interpreted as the ground-state nonet of 1{sup 1}D{sub 2} anti qq states using interaction Lagrangians which couple them to pseudoscalar, vector, and tensor mesons. While the decays of π{sub 2}(1670) and K{sub 2}(1770) can be well described, the decays of the isoscalar states η{sub 2}(1645) and η{sub 2}(1870) can be brought in agreement with the present experimental data only if the mixing angle between nonstrange and strange states is surprisingly large (about -42 {sup circle}, similar to the mixing in the pseudoscalar sector, in which the chiral anomaly is active). Such a large mixing angle is however at odd with all other conventional quark-antiquark nonets: if confirmed, a deeper study of its origin will be needed in the future. Moreover, the anti qq assignment of pseudotensor states predicts that the ratio [η{sub 2}(1870) → a{sub 2}(1320) π]/[η{sub 2}(1870) → f{sub 2}(1270) η] is about 23.5. This value is in agreement with Barberis et al., (20.4 ± 6.6), but disagrees with the recent reanalysis of Anisovich et al., (1.7 ± 0.4). Future experimental studies are necessary to understand this puzzle. If Anisovich's value is confirmed, a simple nonet of pseudoscalar mesons cannot be able to describe data (different assignments and/or additional states, such as an hybrid state, will be needed). In the end, we also evaluate the decays of a pseudoscalar glueball into the aforementioned conventional anti qq states: a sizable decay into K{sub 2}{sup *}(1430) K and a{sub 2}(1230) π together with a vanishing decay into pseudoscalar-vector pairs (such as ρ(770) π and K*(892) K) are expected. This information can be helpful in future studies of glueballs at the ongoing BESIII and at the future PANDA experiments. (orig.)
Phenomenology of pseudotensor mesons and the pseudotensor glueball
Koenigstein, Adrian; Giacosa, Francesco
2016-12-01
We study the decays of the pseudotensor mesons (π2(1670), K2(1770), η2(1645), η2(1870)) interpreted as the ground-state nonet of 11D2 bar{q}q states using interaction Lagrangians which couple them to pseudoscalar, vector, and tensor mesons. While the decays of π2(1670) and K2(1770) can be well described, the decays of the isoscalar states η2(1645) and η2(1870) can be brought in agreement with the present experimental data only if the mixing angle between nonstrange and strange states is surprisingly large (about -42°, similar to the mixing in the pseudoscalar sector, in which the chiral anomaly is active). Such a large mixing angle is however at odd with all other conventional quark-antiquark nonets: if confirmed, a deeper study of its origin will be needed in the future. Moreover, the bar{q}q assignment of pseudotensor states predicts that the ratio [η2(1870) → a2(1320) π]/[η2(1870) → f2(1270) η] is about 23.5. This value is in agreement with Barberis et al., (20.4 ± 6.6), but disagrees with the recent reanalysis of Anisovich et al., (1.7 ± 0.4). Future experimental studies are necessary to understand this puzzle. If Anisovich's value is confirmed, a simple nonet of pseudoscalar mesons cannot be able to describe data (different assignments and/or additional states, such as an hybrid state, will be needed). In the end, we also evaluate the decays of a pseudoscalar glueball into the aforementioned conventional bar{q}q states: a sizable decay into K^{ast}2(1430) K and a2(1230) π together with a vanishing decay into pseudoscalar-vector pairs (such as ρ(770) π and K^{ast}(892) K) are expected. This information can be helpful in future studies of glueballs at the ongoing BESIII and at the future PANDA experiments.
Constraints on the $\\eta \\eta'$ decay rate of a scalar glueball from gauge/gravity duality
Brünner, Frederic
2015-01-01
Predictions of glueball decay rates in the holographic Witten-Sakai-Sugimoto model for low-energy QCD can be uniquely extended to include finite quark masses up to an as yet undetermined parameter in the coupling of glueballs to the nonanomalous part of the pseudoscalar mass terms. The assumption of a universal coupling of glueballs to mass terms of the full nonet of pseudoscalar mesons leads to flavor asymmetries in the decay rates of scalar glueballs that agree well with experimental data for the glueball candidate $f_0(1710)$ and implies a vanishing decay rate into $\\eta\\eta'$ pairs, for which only upper bounds for the $f_0(1710)$ meson are known at present from experiment. Relaxing this assumption, the holographic model gives a tight correlation between the decay rates into pairs of pseudo-Goldstone bosons of same type and $\\eta\\eta'$ pairs. If $\\Gamma(G\\to KK)/\\Gamma(G\\to\\pi\\pi)$ is kept within the range reported currently by the Particle Data Group for the $f_0(1710)$ meson, the rate $\\Gamma(G\\to\\eta\\et...
Many-Body Approach to Mesons, Hybrids and Glueballs
Cotanch, S R; Cotanch, Stephen R.; Llanes-Estrada, Felipe J.
2000-01-01
We represent QCD at the hadronic scale by means of an effective Hamiltonian, H, formulated in the Coulomb gauge. As in the Nambu-Jona-Lasinio model, chiral symmetry is dynamically broken, however our approach is renormalizable and also includes confinement through a linear potential with slope specified by lattice gauge theory. We perform a comparative study of alternative many-body techniques for approximately diagonalizing H: BCS for the vacuum ground state; TDA and RPA for the excited hadron states. We adequately describe the experimental meson and lattice glueball spectra and perform the first relativistic, three quasiparticle calculation for hybrid mesons. In general agreement with alternative theoretical approaches, we predict the lightest hybrid states near but above 2 GeV, indicating the two recently observed $J^{PC} = 1^{-+}$ exotics at 1.4 and 1.6 GeV are of a different, perhaps four quark, structure. We also detail a new isospin dependent interaction from $q\\bar{q}$ color octet annihilation (analog...
Glueball Regge trajectories from gauge/string duality and the Pomeron
Boschi-Filho, H; Carrion, H L; Boschi-Filho, Henrique; Braga, Nelson R. F.; Carrion, Hector L.
2005-01-01
The spectrum of light baryons and mesons has been reproduced recently by Brodsky and Teramond from a holographic dual to QCD inspired in the AdS/CFT correspondence. They associate angular momenta in the string compact space with four dimensional angular momenta of the dual QCD states. We use this approach to estimate masses of glueball states with different spins and their excitations. We consider Dirichlet and Neumann boundary conditions and find approximate linear Regge trajectories for these glueballs. In particular the Neumann case is consistent with the Pomeron trajectory.
Renormalization of Anisotropy and Glueball Masses on Tadpole Improved Lattice Gauge Action
Loan, M; Hamer, C; Loan, Mushtaq; Byrnes, Tim; Hamer, Chris
2003-01-01
The Numerical calculations for tadpole-improved U(1) lattice gauge theory in three-dimensions on anisotropic lattices have been performed using standard path integral Monte Carlo techniques. Using average plaquette tadpole renormalization scheme, simulations were done with temporal lattice spacings much smaller than the spatial ones and results were obtained for the string tension, the renormalized anisotropy and scalar glueball masses. We find, by comparing the `regular' and `sideways' potentials, that tadpole improvement results in very little renormalization of the bare anisotropy and reduces the discretization errors in the static quark potential and in the glueball masses.
Spectroscopy with glueballs and the role of f_0(1370)
Ochs, Wolfgang
2013-01-01
The existence of glueballs, bound states of gluons, is one of the basic predictions of QCD; the lightest state is expected to be a scalar. The experimental situation, however, is still ambiguous. The existence of f_0(1370) would point to a supernumerous state within the nonet classification of scalars and would therefore provide a hint towards a glueball. In this talk we summarize some arguments in favour and against the existence of f_0(1370) and discuss schemes with and without this state included.
Inclusive Glueball Production in High-Energy p+p(p-) Collisions
彭宏安; 段春贵; 何祯民
2001-01-01
Using the factorizable character of amplitudes for the double diffractive process in the Landshoff-Nachtmann model, we have discussed the inclusive glueball production in high-energy pp collisions via the fusion process of two non-perturbative gluons, and have compared it with the double diffractive alike process. We found that, as the c.m. energy Ecms increases from 20 to 20 000 GeV, the cross sections of the latter process are about one to two orders larger than the former. Such an outcome could be explained from the hypothesis of duality between glueballs and pomeron.
Physical observables from boundary artifacts: scalar glueball in Yang-Mills theory
Chowdhury, Abhishek; Maiti, Jyotirmoy
2015-01-01
By relating the functional averages of the time slice energy density in simulations with Open (O) and Periodic (P) boundary conditions (BCs) respectively for $SU(3)$ lattice gauge theory, we show that the scalar glueball mass and the glueball to vacuum matrix element can be extracted very efficiently from the former. The results are compared with those extracted from the two point function of the time slice energy density (both PBC and OBC). The scaling properties of the mass and the matrix element are studied with the help of Wilson (gradient) flow.
Phenomenology of glueballs and scalar-isoscalar quarkonia within an effective hadronic model of QCD
Janowski, Stanislaus
2015-11-06
This thesis is addressed to study the vacuum phenomenology of the scalar-isoscalar sector in the energy region between 1 and 2 GeV in the framework of the extended linear sigma model (eLSM). We found two solutions of the eLSM in the case of N{sub f}=2. In both solutions the resonance f{sub 0}(1370) was predominantly the non-strange anti qq state while the glueball was in one solution predominantly f{sub 0}(1500) and in the other one predominantly f{sub 0}(1710). Calculations of the three-flavored eLSM yield an unambiguous result where f{sub 0}(1370) was, as previously, predominantly the non-strange, while f{sub 0}(1500) is predominantly the strange quark-antiquark meson, and finally the resonance f{sub 0}(1710) turns out to be predominantly a scalar glueball. Our calculations are based on the assumption that the decay width of the scalar glueball is narrow (Γ{sub G}
Pure QCD in small volumes and the low lying glueball spectrum
Korthals Altes, C.P. (Centre National de la Recherche Scientifique, 13 - Marseille (France). Centre de Physique Theorique 2)
1989-07-01
We give a pedagogical review of perturbative calculations in small volumes of the low-lying glueball mass-spectrum. Various boundary conditions are compared. Twisted boundary conditions, respecting cubic invariance, are shown to be very useful in obtaining numerical mass-spectra. (orig.).
SU( N ) gauge theories in 2+1 dimensions: glueball spectra and k-string tensions
Athenodorou, Andreas; Teper, Michael
2017-02-01
We calculate the low-lying glueball spectrum and various string tensions in SU( N ) lattice gauge theories in 2 + 1 dimensions, and extrapolate the results to the continuum limit. We do so for for the range N ∈ [2 , 16] so as to control the N -dependence with a useful precision. We observe a number of striking near-degeneracies in the various J PC sectors of the glueball spectrum, in particular between C = + and C = - states. We calculate the string tensions of flux tubes in a number of representations, and provide evidence that the leading correction to the N -dependence of the k-string tensions is ∝ 1 /N rather than ∝ 1 /N 2, and that the dominant binding of k fundamental flux tubes into a k-string is via pairwise interactions. We comment on the possible implications of our results for the dynamics of these gauge theories.
Search for JPC=even++ glueballs in radiative decay of J/Ψ
无
2000-01-01
Based on the general analysis of decay width and branching ratio of two pseudo scalar meson channels, two sets of discriminants between mesons and glueballs for I=0,JPC=even++ unflavored hadrons with the mass between 1.2 and 2.9 GeV are suggested. Known I=0, JPC=2++, f2(1525) particle is discriminated as a typical meson. The way to discriminate new I=0, JPC=even++ unflavored hadrons is discussed.
Search for JPC = even++ glueballs in radiative decay of J/Ψ
高崇寿
2000-01-01
Based on the general analysis of decay width and branching ratio of two pseudo scalar meson channels, two sets of discriminants between mesons and glueballs for l = 0, J1PC = even++ un-flavored hadrons with the mass between 1.2 and 2.9 GeV are suggested. Known l = 0, JPC = 2++, f2(l525) particle is discriminated as a typical meson. The way to discriminate new l = 0, JPC = even++ unflavored hadrons is discussed.
Glueball and meson propagators of any spin in large-N QCD
Bochicchio, Marco
2013-01-01
We prove an asymptotic structure theorem for glueball and meson propagators of any spin in large-N QCD and in n=1 SUSY QCD with massless quarks, that determines asymptotically the residues of the poles of the propagators in terms of their anomalous dimensions and of the spectral density of the masses. The asymptotic theorem follows by the severe constraints on the propagators of large-N QCD with massless quarks, or of any large-N confining asymptotically free gauge theory massless in perturbation theory, that arise by perturbation theory in conjunction with the renormalization group and by the OPE on the ultraviolet side. The asymptotic theorem is inspired by a recently proposed Topological Field Theory (TFT) underlying large-N pure YM, that computes sums of the scalar and of the pseudoscalar correlators satisfying the asymptotic theorem and that implies for the large-N joint scalar and pseudoscalar glueball spectrum exact linearity in the masses squared. On the infrared side we test the prediction of the exa...
马维兴; Liu,LC
2000-01-01
讨论了高能强子-强子散射过程中的坡密子以及坡密子的QCD内容．认为坡密子有可能就是具有量子数IG＝0+，JPC＝2++的张量胶子球ξ(2 230)．用雷其化胶子球模型计算了高能质子-质子散射截面和坡密子-核子的耦合参数β．理论结果与实验的要求一致．%The pomeron in high energy hadron-hadron scattering as well as the QCD nature of the pomeron are discussed.We claimed that the pomeron may be the tenser glueball ξ(2 230) with quantum number IG ＝0+, JPC＝2++. Under thisreggeized glueball model the cross section of high energy proton-proton scattering and the coupling parameter of the pomeron-nucleon, β, are calculated. The theoretical results of the present model are in good agreement with experimental data.
Pallante, E.
2015-01-01
We discuss properties of non-Abelian gauge theories that change significantly across the lower edge of the conformal window. Their probes are the topological observables, the meson spectrum and the scalar glueball operator. The way these quantities change tells about the way conformal symmetry is
Dynamics of Glueball and $q\\overline{q}$ production in the central region of p p collisions
Close, Francis Edwin; Schuler, G A
2000-01-01
We explain the phi and t dependences of mesons with JPC = 0pm +,1^++,2pm +$ produced in the central region of pp collisions. For the 0++ and 2++ sector this reveals a systematic behaviour in the data that appears to distinguish between qqbar and non-qqbar or glueball candidates.
Ahmed, Chaara El Mouez
Nous avons etudie les relations de dispersion et la diffusion des glueballs et des mesons dans le modele U(1)_{2+1} compact. Ce modele a ete souvent utilise comme un simple modele de la chromodynamique quantique (QCD), parce qu'il possede le confinement ainsi que les etats de glueballs. Par contre, sa structure mathematique est beaucoup plus simple que la QCD. Notre methode consiste a diagonaliser l'Hamiltonien de ce modele dans une base appropriee de graphes et sur reseau impulsion, afin de generer les relations de dispersion des glueballs et des mesons. Pour la diffusion, nous avons utilise la methode dependante du temps pour calculer la matrice S et la section efficace de diffusion des glueballs et des mesons. Les divers resultats obtenus semblent etre en accord avec les travaux anterieurs de Hakim, Alessandrini et al., Irving et al., qui eux, utilisent plutot la theorie des perturbations en couplage fort, et travaillent sur un reseau espace-temps.
Sandbrink, Dirk
2015-01-26
One of the most promising candidates to describe the physics beyond the standard model is the so-called supersymmetry. This work was created in the context of the DESY-Muenster-Collaboration, which studies in particular the N=1 supersymmetric Yang-Mills theory (SYM). SYM is a comparatively simple theory, which is therefore well-suited to study the expected properties of a supersymmetric theory with the help of Monte Carlo simulations on the lattice. This thesis is focused on the numerical determination of the quarkpotential, the glueball masses and the phase structur of the N=1 supersymmetric Yang-Mills theory. The quarkpotential is used to calculate the Sommer scale, which in turn is needed to convert the dimensionless lattice spacing into physical units. Glueballs are hypothetical particles built out of gluons, their masses are relatively hard to determine in lattice simulations due to their pure gluonic nature. For this reason, various methods are studied to reduce the uncertainties of the mass determination. The focus lies on smearing methods and their use in variational smearing as well as on the use of different glueball operators. Lastly, a first look is taken at the phase diagram of the model at finite temperature. Various simulations have been performed at finite temperature in parallel to those performed at temperature zero to analyse the behaviour of the Polyakov loop and the gluino condensate in greater detail.
Search for the $0^{--}$ Glueball in $\\Upsilon(1S)$ and $\\Upsilon(2S)$ decays
Jia, S; Yuan, C Z; Adachi, I; Aihara, H; Said, S Al; Asner, D M; Aushev, T; Ayad, R; Babu, V; Badhrees, I; Bakich, A M; Bansal, V; Barberio, E; Behera, P; Bhuyan, B; Biswal, J; Bonvicini, G; Bozek, A; Bračko, M; Browder, T E; Červenkov, D; Chang, P; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Cho, K; Choi, S -K; Choi, Y; Cinabro, D; Dash, N; Di Carlo, S; Drásal, Z; Dutta, D; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Fulsom, B G; Gaur, V; Gabyshev, N; Garmash, A; Gillard, R; Goldenzweig, P; Golob, B; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; Hedges, M T; Hou, W -S; Iijima, T; Inami, K; Inguglia, G; Ishikawa, A; Itoh, R; Jaegle, I; Joffe, D; Joo, K K; Julius, T; Kang, K H; Katrenko, P; Kawasaki, T; Kichimi, H; Kiesling, C; Kim, D Y; Kim, H J; Kim, J B; Kim, K T; Kim, M J; Kim, S H; Kim, Y J; Kodyš, P; Korpar, S; Kotchetkov, D; Križan, P; Krokovny, P; Kuhr, T; Kulasiri, R; Kuzmin, A; Kwon, Y -J; Lange, J S; Li, C H; Li, L; Li, Y; Gioi, L Li; Libby, J; Liventsev, D; Lubej, M; Luo, T; Masuda, M; Matsuda, T; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Moon, H K; Mori, T; Nakao, M; Nanut, T; Nath, K J; Natkaniec, Z; Nayak, M; Niiyama, M; Nisar, N K; Nishida, S; Ogawa, S; Okuno, S; Ono, H; Onuki, Y; Ostrowicz, W; Pakhlova, G; Pal, B; Park, C -S; Park, H; Pestotnik, R; Piilonen, L E; Pulvermacher, C; Ritter, M; Rostomyan, A; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Savinov, V; Schneider, O; Schnell, G; Schwanda, C; Seino, Y; Senyo, K; Sevior, M E; Shebalin, V; Shibata, T -A; Shiu, J -G; Shwartz, B; Simon, F; Sokolov, A; Solovieva, E; Starič, M; Strube, J F; Sumihama, M; Sumiyoshi, T; Suzuki, K; Takizawa, M; Tamponi, U; Tanida, K; Tenchini, F; Uchida, M; Uglov, T; Unno, Y; Uno, S; Urquijo, P; Usov, Y; Van Hulse, C; Varner, G; Vorobyev, V; Wang, C H; Wang, M -Z; Wang, P; Watanabe, Y; Won, E; Yamashita, Y; Ye, H; Yelton, J; Zhang, Z P; Zhilich, V; Zhukova, V; Zhulanov, V; Zupanc, A
2016-01-01
We report the first search for the $J^{PC}=0^{--}$ glueball in $\\Upsilon(1S)$ and $\\Upsilon(2S)$ decays with data samples of $(102\\pm2)$ million and $(158\\pm4)$ million events, respectively, collected with the Belle detector. No significant signals are observed in any of the proposed production modes, and the 90\\% credibility level upper limits on their branching fractions in $\\Upsilon(1S)$ and $\\Upsilon(2S)$ decays are obtained. The inclusive branching fractions of the $\\Upsilon(1S)$ and $\\Upsilon(2S)$ decays into final states with a $\\chi_{c1}$ are measured to be $\\BR(\\Upsilon(1S)\\to \\chi_{c1}+ anything) = (1.90\\pm 0.43(stat.)\\pm 0.14(syst.))\\times 10^{-4}$ with an improved precision over prior measurements and $\\BR(\\Upsilon(2S)\\to \\chi_{c1}+ anything) = (2.24\\pm 0.44(stat.)\\pm 0.20(syst.))\\times 10^{-4}$ for the first time.
Zhao, Qiang; Zou, Bing-Song; Ma, Zhong-Biao
2005-12-01
We investigate the correlations between the scalar meson configurations and Okuba-Zweig-Iizuka (OZI) rule violations in the hadronic decays of heavy quarkonia, e.g., J/ψ and ϒ, into isoscalar vector meson ( ϕ and ω) and scalar mesons ( f(1710), f(1500), and f(1370)). It shows that the dramatic change of the values of the branching ratio fraction of ϕf/ωf from low (e.g., in J/ψ decays) to high energies (e.g., in ϒ decays) will not only test the glueball- QQbar mixings, but also provide important information about the mysterious OZI-rule violations within the scalars.
Della Morte, Michele
2011-01-01
We make use of the global symmetries of the Yang-Mills theory on the lattice to design a new computational strategy for extracting glueball masses and matrix elements which achieves an exponential reduction of the statistical error with respect to standard techniques. By generalizing our previous work on the parity symmetry, the partition function of the theory is decomposed into a sum of path integrals each giving the contribution from multiplets of states with fixed quantum numbers associated to parity, charge conjugation, translations, rotations and central conjugations Z_N^3. Ratios of path integrals and correlation functions can then be computed with a multi-level Monte Carlo integration scheme whose numerical cost, at a fixed statistical precision and at asymptotically large times, increases power-like with the time extent of the lattice. The strategy is implemented for the SU(3) Yang--Mills theory, and a full-fledged computation of the mass and multiplicity of the lightest glueball with vacuum quantum ...
Della Morte, Michele; Giusti, Leonardo
2011-05-01
We make use of the global symmetries of the Yang-Mills theory on the lattice to design a new computational strategy for extracting glueball masses and matrix elements which achieves an exponential reduction of the statistical error with respect to standard techniques. By generalizing our previous work on the parity symmetry, the partition function of the theory is decomposed into a sum of path integrals each giving the contribution from multiplets of states with fixed quantum numbers associated to parity, charge conjugation, translations, rotations and central conjugations Z N 3. Ratios of path integrals and correlation functions can then be computed with a multi-level Monte Carlo integration scheme whose numerical cost, at a fixed statistical precision and at asymptotically large times, increases power-like with the time extent of the lattice. The strategy is implemented for the SU(3) Yang-Mills theory, and a full-fledged computation of the mass and multiplicity of the lightest glueball with vacuum quantum numbers is carried out at a lattice spacing of 0.17 fm.
Top-down holographic G-structure glueball spectroscopy at (N)LO in N and finite coupling
Sil, Karunava; Yadav, Vikas; Misra, Aalok [Indian Institute of Technology, Department of Physics, Roorkee, Uttaranchal (India)
2017-06-15
The top-down type IIB holographic dual of large-N thermal QCD as constructed in Mia et al. (Nucl Phys B 839:187, 2010) involving a fluxed resolved warped deformed conifold, its delocalized type IIA Strominger-Yau-Zaslow-mirror (SYZ-mirror) as well as its M-theory uplift constructed in Dhuria and Misra (JHEP 1311:001, 2013) - both in the finite coupling g{sub s}
Search for the glueball candidates f0(1500) and fJ(1710) in /γγ collisions
Barate, R.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Alemany, R.; Bravo, S.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Graugès, E.; Juste, A.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L. M.; Pacheco, A.; Riu, I.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Boix, G.; Buchmüller, O.; Cattaneo, M.; Cerutti, F.; Ciulli, V.; Dissertori, G.; Drevermann, H.; Forty, R. W.; Frank, M.; Greening, T. C.; Halley, A. W.; Hansen, J. B.; Harvey, J.; Janot, P.; Jost, B.; Lehraus, I.; Leroy, O.; Mato, P.; Minten, A.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Schmitt, M.; Schneider, O.; Spagnolo, P.; Tejessy, W.; Teubert, F.; Tournefier, E.; Wright, A. E.; Ajaltouni, Z.; Badaud, F.; Chazelle, G.; Deschamps, O.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Rensch, B.; Wäänänen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Blondel, A.; Bonneaud, G.; Brient, J.-C.; Rougé, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Focardi, E.; Parrini, G.; Zachariadou, K.; Corden, M.; Georgiopoulos, C.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Lynch, J. G.; Negus, P.; O'Shea, V.; Raine, C.; Teixeira-Dias, P.; Thompson, A. S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Girone, M.; Goodsir, S.; Martin, E. B.; Marinelli, N.; Sciabà, A.; Sedgbeer, J. K.; Thomson, E.; Williams, M. D.; Ghete, V. M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Buck, P. G.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W. L.; Robertson, N. A.; Williams, M. I.; Giehl, I.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; Wachsmuth, H.; Zeitnitz, C.; Aubert, J. J.; Bonissent, A.; Carr, J.; Coyle, P.; Payre, P.; Rousseau, D.; Aleppo, M.; Antonelli, M.; Ragusa, F.; Büscher, V.; Dietl, H.; Ganis, G.; Hüttmann, K.; Lütjens, G.; Mannert, C.; Männer, W.; Moser, H.-G.; Schael, S.; Settles, R.; Seywerd, H.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Azzurri, P.; Boucrot, J.; Callot, O.; Chen, S.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, P.; Jacholkowska, A.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Bagliesi, G.; Boccali, T.; Bozzi, C.; Calderini, G.; Dell'Orso, R.; Ferrante, I.; Foà, L.; Giassi, A.; Gregorio, A.; Ligabue, F.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sguazzoni, G.; Tenchini, R.; Venturi, A.; Verdini, P. G.; Blair, G. A.; Cowan, G.; Green, M. G.; Medcalf, T.; Strong, J. A.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Thompson, J. C.; Tomalin, I. R.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Konstantinidis, N.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L. F.; Affholderbach, K.; Böhrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Misiejuk, A.; Prange, G.; Sieler, U.; Giannini, G.; Gobbo, B.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Elmer, P.; Ferguson, D. P. S.; Gao, Y.; González, S.; Hayes, O. J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P. A., III; Nielsen, J.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, J.; von Wimmersperg-Toeller, J. H.; Wu, S. L.; Wu, X.; Zobernig, G.
2000-01-01
Data taken with the ALEPH detector at LEP1 have been used to search for /γγ production of the glueball candidates f0(1500) and fJ(1710) via their decay to π+π-. No signal is observed and upper limits to the product of /γγ width and π+π- branching ratio of the f0(1500) and the fJ(1710) have been measured to beΓ(γγ-- >f0(1500)).BR(f0(1500)-- >π+π-)fJ(1710)).BR(fJ(1710)-- >π+π-)<0.55keV at 95% confidence level.
Zhao, Q; Zou Bing Song
2005-01-01
We investigate the correlations between the scalar meson configurations and Okuba-Zweig-Iizuka (OZI) rule violations in the hadronic decays of heavy quarkonia, e.g. $J/\\psi$ and $\\Upsilon$, into isoscalar vector meson ($\\phi$ and $\\omega$) and scalar mesons ($f_0(1710)$, $f_0(1500)$, and $f_0(1370)$). It shows that the dramatic change of the values of the branching ratio fraction of $\\phi f_0/\\omega f_0$ from low (e.g. in $J/\\psi$ decays) to high energies (e.g. in $\\Upsilon$ decays) will not only test the glueball-$Q\\bar{Q}$ mixings, but also provide important information about the mysterious OZI-rule violations within the scalars.
On the proximity of $f_0(1500)$ and $f_0(1710)$ to the scalar glueball
Fariborz, Amir H; Asrar, Abdorreza
2015-01-01
Within a nonlinear chiral Lagrangian framework, the underlying mixings among quark-antiquark, four-quark and glue components of $f_0(1500)$ and $f_0(1710)$ are studied in a global picture that includes all isosinglet scalar mesons below 2 GeV. The quark components are introduced in the Lagrangian in terms of two separate nonets (a quark-antiquark nonet and a four-quark nonet) which can mix with each other and with a scalar glueball. The free parameters of the Lagrangian are studied by a simultaneous fit to more than 20 experimental data and constraints on the mass spectrum, decay widths, and decay ratios of the isosinglet scalars below 2 GeV. Moreover, constraints on the mass spectrum and decay widths of isodoublet and isovector scalars below 2 GeV as well as pion-pion scattering amplitude are also taken into account. The insights gained in this global picture, due to the complexities of the mixings as well as the experimental uncertainties, are mainly qualitative but are relatively robust, and reveal that th...
Barate, R; Ghez, P; Goy, C; Lees, J P; Merle, E; Minard, M N; Pietrzyk, B; Alemany, R; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Pacheco, A; Riu, I; Ruiz, H; Colaleo, A; Creanza, D; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Boix, G; Buchmüller, O L; Cattaneo, M; Cerutti, F; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Greening, T C; Halley, A W; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Leroy, O; Mato, P; Minten, Adolf G; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tournefier, E; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Rougé, A; Rumpf, M; Swynghedauw, M; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Teixeira-Dias, P; Thompson, A S; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Sciabà, A; Sedgbeer, J K; Thomson, E; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Robertson, N A; Williams, M I; Giehl, I; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Wachsmuth, H W; Zeitnitz, C; Aubert, Jean-Jacques; Bonissent, A; Carr, J; Coyle, P; Payre, P; Rousseau, D; Aleppo, M; Antonelli, M; Ragusa, F; Büscher, V; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Veillet, J J; Videau, I; Zerwas, D; Bagliesi, G; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Ferrante, I; Foà, L; Giassi, A; Gregorio, A; Ligabue, F; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sguazzoni, G; Tenchini, Roberto; Venturi, A; Verdini, P G; Blair, G A; Cowan, G D; Green, M G; Medcalf, T; Strong, J A; Botterill, David R; Clifft, R W; Edgecock, T R; Norton, P R; Thompson, J C; Tomalin, I R; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Grupen, Claus; Hess, J; Misiejuk, A; Prange, G; Sieler, U; Giannini, G; Gobbo, B; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Von Wimmersperg-Töller, J H; Wu Sau Lan; Wu, X; Zobernig, G
2000-01-01
Data taken with the ALEPH detector at LEP1 have been used to search for gamma gamma production of the glueball candidates f0(1500) and fJ(1710) via their decay to pi+pi-. No signal is observed and upper limits to the product of gamma gamma width and pi+pi- branching ratio of the f0(1500) and the fJ(1710) have been measured to be Gamma_(gamma gamma -> f0(1500)). BR(f0(1500)->pi+pi-) fJ(1710)). BR(fJ(1710)->pi+pi-) < 0.55 keV at 95\\-onfidence level.
Dudal, David; Baulieu, Laurent; Sorella, Silvio P; Guimaraes, Marcelo S; Huber, Markus Q; Oliveira, Orlando; Zwanziger, Daniel
2010-01-01
During recent years, a good agreement was found between the analytical derivation and the numerical simulation of the Landau gauge gluon and ghost propagators. We mention the Schwinger-Dyson and Gribov-Zwanziger formalism for the analytical work. Although the agreement between several approaches is nice, these propagators do not correspond to the relevant physical degrees of freedom. In the case of pure gauge theories, one should start to study the glueball correlators. We shall try to explain why it looks like a hard challenge to go from the unphysical to the physical propagators in the case of the Gribov-Zwanziger theory (but similar conclusions might hold for other approaches giving similar propagators).
Longacre, R S; Bugg, D V
2004-01-01
Four separate experiments, observing the OZI forbidden disconnected reaction pi- p -> phi phi n with increasing statistics were consistent. These experiments very selectively completely broke down the OZI suppression by 3 phi phi resonances with IG JPC = 0+ 2++ in the observed mass region 2.038 to 2.600 GeV. The only viable proposed explanation has been that the IG JPC = 0+ 2++ Glueball expected in this mass region caused the hard glue in the disconnection to resonate and very selectively breakdown the OZI suppression for its quantum numbers only. Recently a p p central production spin analysis found the f2(1950) had a dominant decay mode f2(1270) pi pi. We consider if it is related to the phi phi resonances, and find that it likely is.
XIONG Wen-Yuan; HU Zhao-Hui; WANG Xin-Wen; ZHOU Li-Juan; XIA Li-Xin; MA Wei-Xing
2008-01-01
that the Reggeon exchange is an exchange of multigluon, the color singlet gluon bound state. In particular, the Pomeron could be a Reggeized tensor glueba11 ξ(2230) with mass of 2.23 GeV, quantum numbers IG, JPC = 0+, 2++ and decay width of about 100 MeV. The glueball exchange theory reproduces data quite well. Accordingly, we believe that the Odderon, consisting of three Reggeized gluons, and predicted by QCD, should also contribute to hadron-hadron scattering and many other diffractive processes. We search for the Odderon by studying pp and pp elastic scatterings at high energies. Our investigations on the differential cross section da / dt of hadron-hadron scattering at various energies and comparisons with experimental data show that the Odderon plays an essential role in fitting to data. Therefore, we suggest that the measurements should be urgently done in order to confirm the existences of the Odderon and to test QCD.
2002-01-01
The experiment is aimed at:\\\\ a)\tthe search for neutral mesons and glueballs produced in central hadron-proton collisions and, simultaneously, \\\\b)\tthe study of inclusive hadronic production of neutral heavy quark mesons. \\\\ \\\\These states are observed through their decay into many photons in the 4092-cell electromagnetic Calorimeter GAMS-4000. \\\\ \\\\The NAl2 setup is supplemented with a forward magnetic spectrometer equiped with multiwire Proportional chambers (MWPC) and newly developed microstrip gas chambers (MSGC). The high spatial resolution of the latter allows to measure the momentum loss of the interacting hadron in the liquid hydrogen target (LH$_{2}$) to a precision better than 1.5 GeV/c, i.e. $3 \\times 10^{-3}$ for a 450 GeV/c proton. A system for the measurement of the time of flight (TOF) and ionization of the proton recoiling in the target completes the constraints on neutral meson production reactions. \\\\ \\\\A fast decision on the energy deposited in GAMS and the momentum of the interacting hadro...
刘大庆; 吴济民; 陈莹
2002-01-01
We develop a new approach to constructing the lattice operators for the calculation of the glueball mass, which is based on the connection between the continuum limit of the chosen operator and the quantum number JPc of the state. The spin of the state is then determined uniquely and directly in numerical simulation. Furthermore, the approach can be applied to the calculation of the mass of glueball states with any spin. J. Under the quenched approximation, we present our preliminary results in SU(3) pure gauge theory for the mass of 0++ state and 2++ state, which are 1754(85)(86) MeV and 2417(56)(117) MeV, respectively.%发展了一种为了计算胶球质量而构造格点算符的新途径.基于所选用算符的连续极限与状态量子数JPC两者之间的联系,状态的自旋就可以在数值模拟中唯一和直接地被确定下来.进而,这一途径可以被应用于计算任意自旋J的胶球质量.在淬火近似下,给出在SU(3)纯规范场中0++态和2++态胶球质量的初步结果,它们分别是1754(85)(86)MeV和2417(56)(17)MeV.
Gastaldi, U.
1987-02-20
Low energy resolution protonium spectroscopy with a large acceptance and high granularity X-ray Drift Chamber offers a new physical instrument to study the dependence of p anti p annihilation at rest on angular momentum and to search for glueball, hybrid, multiquark and conventional mesonic states with narrow and also broad width. This tool has been developed at LEAR within the ASTERIX experiment and will be systematically or in part employed in ACOL time by two new experiments concerned with hadron spectroscopy and dynamics of nucleon-antinucleon interactions. High energy resolution protonium spectroscopy is feasible with an improvement by a factor 1000 over pre-ACOL experiments by using beams of p anti p atoms produced in flight inside LEAR (where H/sup -/ ions have to co-rotate with the anti p coast) and going to a detection equipment external to the ring. The limit to the best relative energy resolution attainable is given by the relative momentum dispersion ..delta..p/p of the beams stored in LEAR. The shift and broadening induced by strong interactions on the four sublevels of the 2P level become therefore measurable, and precise measurements on these quantities look feasible for the two sublevels of the 1S ground state. In the second part of this paper we review this approach to high resolution protonium spectroscopy (IDEFIX experiment) and its feasibility aspects. 61 refs., 5 figs., 3 tabs.
李德民; 方建; 郁宏; 沈齐兴
2000-01-01
假定ξ(2230)的自旋宇称为2++,研究了中性张量介子f2(1270), f′ 2(1525)和胶球候选者ξ(2230)的混合,通过对可得到的这3个态的衰变数据的拟合,得到了这3个态的夸克和胶球内容. 并给出了一些关于ξ(2230)衰变的预言.%Assuming the spin-parity JPC of the ξ(2230) is 2++, the mixing of the neutral tensor mesons f2(1270), f′2(1525) and the glueball candidate ξ(2230) are investigated. The glueball-quarkonia content of the f2(1270),f′2(1525) and ξ(2230) is obtained from a detailed fit to the available decay data of these three states. Several predictions for the decays of the ξ(2230) are presented.
Phenomenology of pseudotensor mesons and the pseudotensor glueball
Koenigstein, Adrian
2016-01-01
We study the decays of the pseudotensor mesons $[ \\pi_{2}(1670) , K_{2}(1770) , \\eta_{2}(1645) , \\eta_{2}(1870) ]$ interpreted as the ground-state nonet of $1^1 D_{2}$ $\\bar{q}q$ states using interaction Lagrangians which couple them to pseudoscalar, vector, and tensor mesons. While the decays of $\\pi_2 (1670)$ and $K_2 (1770)$ can be well described, the decays of the isoscalar states $\\eta_2 (1645)$ and $\\eta_2 (1870)$ can be brought in agreement with experimental data only if the mixing angle between nonstrange and strange states is surprisingly large (about $-42^\\circ$, similar to the mixing in the pseudoscalar sector, in which the chiral anomaly is active). Such a large mixing angle is however at odd with all other conventional quark-antiquark nonets: if confirmed, a deeper study of its origin will be needed in the future. Moreover, the $\\bar{q}q$ assignment of pseudotensor states predicts that the ratio $[ \\eta_2 (1870) \\rightarrow a_2 (1320) \\pi]/[\\eta_2 (1870) \\rightarrow f_2 (1270) \\eta]$ is about $23...
Search for the {0}^{--} glueball in {{\rm Y}}\left(1S\right) and {{\rm Y}}\left(2S\right) decays
Jia, S.; Shen, C. P.; Yuan, C. Z.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Barberio, E.; Behera, P.; Bhuyan, B.; Biswal, J.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chang, P.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, K.; Choi, S. -K.; Choi, Y.; Cinabro, D.; Dash, N.; Di Carlo, S.; Doležal, Z.; Drásal, Z.; Dutta, D.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goldenzweig, P.; Golob, B.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; Hedges, M. T.; Hou, W. -S.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Itoh, R.; Jaegle, I.; Joffe, D.; Joo, K. K.; Julius, T.; Kang, K. H.; Katrenko, P.; Kawasaki, T.; Kichimi, H.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kim, Y. J.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kuzmin, A.; Kwon, Y. -J.; Lange, J. S.; Li, C. H.; Li, L.; Li, Y.; Li Gioi, L.; Libby, J.; Liventsev, D.; Lubej, M.; Luo, T.; Masuda, M.; Matsuda, T.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moon, H. K.; Mori, T.; Nakao, M.; Nanut, T.; Nath, K. J.; Natkaniec, Z.; Nayak, M.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Okuno, S.; Ono, H.; Onuki, Y.; Ostrowicz, W.; Pakhlova, G.; Pal, B.; Park, C. -S.; Park, H.; Pestotnik, R.; Piilonen, L. E.; Pulvermacher, C.; Ritter, M.; Rostomyan, A.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shebalin, V.; Shibata, T. -A.; Shiu, J. -G.; Shwartz, B.; Simon, F.; Sokolov, A.; Solovieva, E.; Starič, M.; Strube, J. F.; Sumihama, M.; Sumiyoshi, T.; Suzuki, K.; Takizawa, M.; Tamponi, U.; Tanida, K.; Tenchini, F.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Usov, Y.; Van Hulse, C.; Varner, G.; Vorobyev, V.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, Y.; Widmann, E.; Won, E.; Yamashita, Y.; Ye, H.; Yelton, J.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.; Zupanc, A.
2017-01-01
We report the first search for the J^{PC}= 0^{--} glueball in Yð1SÞ and Y=ð2SÞ decays with data samples of (102 ± 2) × 10^{6} and (158 ± 4) × 10^{6} events, respectively, collected with the Belle detector. No significant signals are observed in any of the proposed production modes, and the 90% credibility level upper limits on their branching fractions in Y(1S) andY(2S) decays are obtained. The inclusive branching fractions of the Y(1S) and Y(2S) decays into final states with a χ_{c1} are measured to be B(Y(1S) → χ_{c}1 þ anything = (1.90± 0.43(stat) ± 0.14(syst)) × 10^{-4} with an improved precision over prior measurements and → χ_{c1} + anything) = (2.24 ±0.44(stat) 0.20(syst)) × 10^{-4} for the first time.
Baryon properties and glueballs from Poincare-covariant bound-state equations
Sanchis-Alepuz, Helios
2012-01-01
In this thesis the covariant Bethe-Salpeter equation formalism is used to study some properties of ground-state baryons. This formalism relies on the knowledge of the interaction kernel among quarks and of the full quark propagator. For the interaction kernel, which is in principle a sum of infinitely many diagrams, I use the Ladder truncation. It amounts to reduce the interaction to a flavor-blind quark-mass independent vector-vector interaction between two quarks, mediated by a dressed gluon. The irreducible three-body interactions are neglected. The full quark propagator is obtained as a solution of the quark Dyson-Schwinger equation which is truncated such that, together with the truncation in the interaction kernel, chiral symmetry is correctly implemented. It is called Rainbow truncation, and together with the truncated kernel equation it constitutes the Rainbow-Ladder truncation of the Bethe-Salpeter equation. Any truncation induces the introduction of a model to account for the properties of the full ...
Topology and glueballs in SU(7) Yang-Mills with open boundary conditions
Amato, Alessandro; Lucini, Biagio
2015-01-01
It is well known that the topology of gauge configurations generated in a Markov Monte-Carlo chain freezes as the continuum limit is approached. The corresponding autocorrelation time increases exponentially with the inverse lattice spacing, affecting the ergodicity of the simulation. In SU(N) gauge theories for large N this problem sets in at much coarser lattice spacings than for N=3. This means that its systematics can be studied on lattices that are smaller in terms of the number of lattice sites. It has been shown that using open boundary conditions in time allows instantons to be created and destroyed, restoring topological mobility and ergodicity. However, with open boundary conditions translational invariance is lost and the influence of spurious states propagating from the boundary into the bulk on physical correlators needs to be carefully evaluated. Moreover, while the total topological charge can be changed, the mobility of instantons across the lattice is still reduced. We consider SU(7) Yang-Mil...
Green's functions and non-singlet glueballs on deformed conifolds
Pufu, Silviu S; Klebanov, Igor R; Lin, Jennifer [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Klose, Thomas, E-mail: spufu@Princeton.EDU [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden)
2011-02-04
We study the Laplacian on Stenzel spaces (generalized deformed conifolds), which are tangent bundles of spheres endowed with Ricci flat metrics. The (2d - 2)-dimensional Stenzel space has SO(d) symmetry and can be embedded in C{sup d} through the equation {Sigma}{sup d}{sub i=1}z{sub i}{sup 2} = {epsilon}{sup 2}. We discuss Green's function with a source at a point on the S{sup d-1} zero section of TS{sup d-1}. Its calculation is complicated by mixing between different harmonics with the same SO(d) quantum numbers due to the explicit breaking by the {epsilon}-deformation of the U(1) symmetry that rotates z{sub i} by a phase. A similar mixing affects the spectrum of normal modes of warped deformed conifolds that appear in gauge/gravity duality. We solve the mixing problem numerically to determine certain bound state spectra in various representations of SO(d) for the d = 4 and d = 5 examples.
Glueballs in large-N YM by localization on critical points
Bochicchio, Marco
2011-01-01
By exploiting in large-N YM the change of variables from the gauge connection to the ASD part of its curvature by a non-SUSY version of the Nicolai map, we show that certain twistor Wilson loops supported on a Lagrangian submanifold of twistor space are localized on lattices of surface operators of Z(N) holonomy that form translational invariant sectors labelled by the magnetic charge k=1,2,...,N-1 at a point. The localization is obtained reducing the loop equation in the ASD variables in the holomorphic gauge, regularized by analytic continuation to Minkowski space-time, to a critical equation, by exploiting the invariance of the twistor Wilson loops by deformations for the addition of backtracking arcs ending with cusps on the singular divisor of surface operators. Alternatively localization is obtained contracting the YM measure in the ASD variables on the fixed points of a semigroup that acts on the fiber of the Lagrangian twistor fibration which twistor Wilson loops are supported on and leaves invariant ...
SU(3) Yang-Mills Hamiltonian in the flux-tube gauge: Strong coupling expansion and glueball dynamics
Pavel, Hans-Peter
2016-01-01
It is shown that the formulation of the SU(3) Yang-Mills quantum Hamiltonian in the "flux-tube gauge" A_{a1}=0 for all a=1,2,4,5,6,7 and A_{a2}=0 for all a=5,7 allows for a systematic and practical strong coupling expansion of the Hamiltonian in \\lambda\\equiv g^{-2/3}, equivalent to an expansion in the number of spatial derivatives. Introducing an infinite spatial lattice with box length a, the "free part" is the sum of Hamiltonians of Yang-Mills quantum mechanics of constant fields for each box, and the "interaction terms" contain higher and higher number of spatial derivatives connecting different boxes. The Faddeev-Popov operator, its determinant and inverse, are rather simple, but show a highly non-trivial periodic structure of six Gribov-horizons separating six Weyl-chambers. The energy eigensystem of the gauge reduced Hamiltonian of SU(3) Yang-Mills mechanics of spatially constant fields can be calculated in principle with arbitrary high precision using the orthonormal basis of all solutions of the corr...
LI Jie-Ming; CHEN Qi-Zhou; GUO Shuo-Hong
2001-01-01
The random phase approximation is applied to the coupled-cluster expansions of lattice gauge theory (LGT). Using this method, wavefunctions are approximated by linear combination of graphs consisting of only one connected Wilson loop. We study the excited state energy and wavefunction in (2 + 1)-D SU(3) LGT up to thc third order. The glueballmass shows a good scaling behavior.``
Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Caron, B.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Furtjes, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harder, K.; Harel, A.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kormos, Laura L.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Leins, A.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, J.; Macpherson, A.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McDonald, W.J.; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schoerner-Sadenius, Thomas; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Siroli, G.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Stephens, K.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Taylor, R.J.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija
2004-01-01
Gluon jets with a mean energy of 22 GeV and purity of 95% are selected from hadronic Z0 decay events produced in e+e- annihilations. A subsample of these jets is identified which exhibits a large gap in the rapidity distribution of particles within the jet. After imposing the requirement of a rapidity gap, the gluon jet purity is 86%. These jets are observed to demonstrate a high degree of sensitivity to the presence of color reconnection, i.e. higher order QCD processes affecting the underlying color structure. We use our data to test three QCD models which include a simulation of color reconnection: one in the Ariadne Monte Carlo, one in the Herwig Monte Carlo, and the other by Rathsman in the Pythia Monte Carlo. We find the Rathsman and Ariadne color reconnection models can describe our gluon jet measurements only if very large values are used for the cutoff parameters which serve to terminate the parton showers, and that the description of inclusive Z0 data is significantly degraded in this case. We concl...
Azimuthal angular distributions in EDDE as a spin-parity analyser and glueball filter for the LHC
Petrov, Vladimir Alexeevich [Institute for High Energy Physics, 142 281, Protvino (Russian Federation); Ryutin, Roman Anatolievich [Institute for High Energy Physics, 142 281, Protvino (Russian Federation); Sobol, Andrei E. [Institute for High Energy Physics, 142 281, Protvino (Russian Federation); Guillaud, Jean-Paul [LAPP, Annecy (France)
2005-06-01
Exclusive Double Diffractive Events (EDDE) are analysed as the source of the information about the central system. The experimental possibilities for the exotic particles searches are considered. From the reggeized tensor current picture some azimuthal angle dependences were obtained to fit the data from the WA102 experiment and to make predictions for the LHC collider.
Pomeron的结构和胶球的强生机制%Structure of the Pomeron and the Mechanism for Strong-Production of the Glueball
彭宏安; 段春贵; 阎占元; 何祯民
2002-01-01
首先强调了在高能强作用软(高强软)过程,特别是在强子散射总截面中,单由Pomeron(IP)交换就渐进地饱和了幺正性条件这件事的重要性. 结合对Landshoff和Nachtmann的IP场论模型适当修改,提出了最大非微扰强作用反应假说. 与此相关,认为IP由这种反应中得出的一对共轭色八重态胶团组成. 通过对修改后的q-弹性振幅虚部图形的物理内涵的考察,一方面预言了高强软过程中会产生组分胶子,胶球态是由两个对撞的组分胶子熔合所形成. 另一方面,通过这里的色胶团单圈图与Gell-mann-Zweig的介子散射时夸克图的对应,论证了IP与胶球态之间存在着Regge极点型的二元性关系.
Amsler, Claude
2000-01-01
The experimental status of glueballs and hybrids is briefly reviewed. Recent results for scalar mesons suggest that f sub 0 (1500) is the ground state scalar glueball. The identification of the first excited glueball state, a tensor, is premature, although candidates are available. We have now evidence for at least two mesons, pi sub 1 (1400) and pi sub 1 (1600), with quantum numbers incompatible with a qq-bar structure.
Stoecker, Horst; Schramm, Stefan; Senzel, Florian; Greiner, Carsten; Beitel, Maxim; Gallmeister, Kai; Gorenstein, Mark; Mishustin, Igor; Vasak, David; Steinheimer, Jan; Struckmeier, Juergen; Vovchenko, Volodymyr; Satarov, Leonid; Xu, Zhe; Zhuang, Pengfei; Csernai, Laszlo P; Sinha, Bikash; Raha, Sibaji; Biró, Tamás Sándor; Panero, Marco
2016-01-01
The early stage of high multiplicity pp, pA and AA collider is represented by a nearly quarkless, hot, deconfined pure gluon plasma. According to pure Yang-Mills Lattice Gauge Theory, this hot pure glue matter undergoes, at a high temperature, $T_c = 270$ MeV, a first order phase transition into a confined Hagedorn-GlueBall fluid. These new scenario should be characterized by a suppression of high $p_T$ photons and dileptons, baryon suppression and enhanced strange meson production. We propose to observe this newly predicted class of events at LHC and RHIC.
彭宏安; 段春贵; 阎占元
2004-01-01
基于J/ψ辐射产生胶球态Gb和湮没为e-e对两过程的中间态和末态都不涉及任何夸克强子而只与强作用的真空性质密切相关这一特性,从另一种角度讨论了这两个过程.利用高能强作用软过程中修改后的pomeron场论模型和相关的最大非微扰强作用反应假定,并考虑到轻的和重的组分夸克在结构上的差异而在模型参数中作出相应的变更后,提出了这两个过程的另一种物理机制,计算了它们的衰变宽度,定出了胶球态与非微扰胶子间的耦合数值,并就此进行了简单的讨论.
Hadron Structure and Modern Spectroscopy
Page, P R
2000-01-01
The colour, flavour, spin and J^PC of glueballs and hybrid mesons and baryons are constructed in an intuitive manner in both the gluon counting and adiabatic definitions. Glueball decay, production and mixing and hybrid meson decay selection rules and production are clarified.
Pomeron interactions from the Einstein-Hilbert action
Iatrakis, Ioannis; Ramamurti, Adith; Shuryak, Edward
2016-08-01
Holographic models of QCD, collectively known as anti-de Sitter/QCD, have been proven useful in deriving several properties of hadrons. One particular feature well reproduced by such models is the Regge trajectories, both for mesons and glueballs. We focus on scalar and tensor glueballs and derive an effective theory for the Pomeron by analytic continuation along the leading trajectory from the tensor glueball. It then follows that the Pomeron, as the tensor glueball itself, should possess a two-index polarization tensor, inherited from the graviton. The three-graviton interaction is deduced from the Einstein-Hilbert action. Using this structure in the cross section of double-Pomeron production of the tensor glueball, we calculate certain angular distributions of production and compare them with those from the CERN WA102 experiment. We find that the agreement is very good for the f2(2300 ) tensor glueball candidate. At the same time, other tensor states—such as f2(1270 ) and f2'(1520 ) —have completely different distributions, which we interpret as a consequence of the fact that they are not glueballs and thus, in our model, unrelated to the gravitational excitations, which are dual to spin-2 glueballs.
Filtering Overpopulated Isoscalar Tensor States with Mass Relations
Burakovsky, L; Burakovsky, Leonid; Page, Philip R.
2000-01-01
The overpopulated isoscalar tensor states are sifted using Schwinger-type mass relations. Two solutions are found: one where the glueball is the fJ(2220), and one where the glueball is more distributed, with f2(1820) having the largest component. The f2(1565) and fJ(1710) cannot be accommodated as glueball-(hybrid) meson mixtures in the absense of significant coupling to decay channels. f2'(1525) -> pi pi is in agreement with experiment. The fJ(2220) decays neither flavour democratically nor is narrow.
Semiclassical string spectrum in a string model dual to large N QCD
Pons, J M; Talavera, P
2004-01-01
We explore the string spectrum in the Witten QCD model by considering classical string configurations, thereby obtaining energy formulas for quantum states with large excitation quantum numbers representing glueballs and Kaluza-Klein states. In units of the string tension, the energies of all states increase as the 't Hooft coupling $\\lambda $ is decreased, except the energies of glueballs corresponding to strings lying on the horizon, which remain constant. We argue that some string solutions can be extrapolated to the small $\\lambda $ regime. We also find the classical mechanics description of supergravity glueballs in terms of point-like string configurations oscillating in the radial direction, and reproduce the glueball energy formula previously obtained by solving the equation for the dilaton fluctuation.
Discovering Uncolored Naturalness in Exotic Higgs Decays
Curtin, David
2015-01-01
Solutions to the hierarchy problem usually require top partners. In standard SUSY or composite Higgs theories, the partners carry SM color and are becoming increasingly constrained by LHC searches. However, theories like Folded SUSY (FS), Twin Higgs (TH) and Quirky Little Higgs (QLH) introduce uncolored top partners, which can be SM singlets or carry electroweak charge. Their small production cross section left doubt as to whether the LHC can effectively probe such scenarios. Typically, these partners are charged under their own mirror color gauge group. In FS and QLH, the absence of light mirror matter allows glueballs to form at the bottom of the mirror spectrum, this is also the case in some TH realizations. The Higgs can decay to these mirror glueballs, with the glueballs decaying into SM particles with potentially observable lifetimes. We undertake the first detailed study of this glueball signature and quantitatively demonstrate the discovery potential of uncolored naturalness via exotic Higgs decays at...
Non-conventional mesons at PANDA
Giacosa, Francesco
2015-04-01
Non-conventional mesons, such as glueballs and tetraquarks, will be in the focus of the PANDA experiment at the FAIR facility. In this lecture we recall the basic properties of QCD and describe some features of unconventional states. We focus on the search of the not-yet discovered glueballs and the use of the extended Linear Sigma Model for this purpose, and on the already discovered but not-yet understood X, Y, Z states.
Determining the Gluonic Content of Isoscalar Mesons
Farrar, Glennys R S
1996-01-01
The gluonic widths of four leading glueball candidates are determined from their production in radiative quarkonium decays, allowing quantitative estimation of their glue content. Lattice predictions for the scalar and tensor channels seem to be in reasonable agareement with present data (allowing for mixing with $q \\bar{q}$ states). However there is a glueball-like-state in the pseudoscalar spectrum whose mass is considerably lower than expected from lattice estimates.
Photoproduction of scalar mesons using CLAS at JLab
Chandavar, Shloka; Hicks, Kenneth; Weygand, Dennis; CLAS Collaboration
2014-09-01
The search for glueballs has been ongoing for decades. The lightest glueball has been predicted by quenched lattice QCD to have a mass in the range of 1.0-1.7 GeV and JPC =0++ . The mixing of glueball states with neighbouring meson states complicates their identification. The f0 (1500) is one of several candidates for the lightest glueball, whose presence in the Ks0 Ks0 channel is investigated in photoproduction using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. This is done by studying the reaction, γp -->fJ p -->Ks0> Ks0p --> 2 (π+π-) p using data from the g12 experiment. A brief description of this analysis, along with a preliminary partial wave analysis results will be presented. The search for glueballs has been ongoing for decades. The lightest glueball has been predicted by quenched lattice QCD to have a mass in the range of 1.0-1.7 GeV and JPC =0++ . The mixing of glueball states with neighbouring meson states complicates their identification. The f0 (1500) is one of several candidates for the lightest glueball, whose presence in the Ks0Ks0 channel is investigated in photoproduction using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. This is done by studying the reaction, γp -->fJ p -->Ks0 Ks0p --> 2 (π+π-) p using data from the g12 experiment. A brief description of this analysis, along with a preliminary partial wave analysis results will be presented. NSF.
Pomeron Interactions from the Einstein-Hilbert Action
Iatrakis, Ioannis; Shuryak, Edward
2016-01-01
Holographic models of QCD, collectively known as AdS/QCD, have been proven useful in deriving several properties of hadrons. One particular feature well reproduced by such models is the Regge trajectories, both for mesons and glueballs. We focus on scalar and tensor glueballs, and derive an effective theory for the Pomeron by analytic continuation along the leading trajectory from the tensor glueball. It then follows that the Pomeron, as the tensor glueball itself, should possess a two-index polarization tensor, inherited from the graviton. The three-graviton interaction is deduced from the Einstein-Hilbert action. Using this structure in the cross section of double-Pomeron production of the tensor glueball, we calculate certain angular distributions of production and compare them with those from the CERN WA102 experiment. We find that the agreement is very good for the $f_2(2300)$ tensor glueball candidate. At the same time, other tensor states -- such as $f_2(1270)$ and $f'_2(1520)$ -- have completely diffe...
Photoproduction of Scalar Mesons Using the CEBAF Large Acceptance Spectrometer (CLAS)
Chandavar, Shloka K.
The search for glueballs has been ongoing for several decades. The lightest glueball has been predicted by quenched lattice QCD to have mass in the range of 1.0--1.7 GeV and JPC = 0++ . The mixing of glueball states with neighbouring meson states complicates their identification and hence several experiments have been carried out over the years to study the glueball candidates. By analyzing the decay channels and production mechanisms of these candidates, their glueball content can theoretically be determined. In reality, a lot of confusion still exists about the status of these glueball candidates. The f0(1500) is one of several contenders for the lightest glueball, which has been extensively studied in several different kinds of experiments. However, there exists no photoproduction data on this particle. In the analysis presented in this dissertation, the presence of the f0(1500) in the KS 0KS0 channel is investigated in photoproduction using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility, also called Jefferson Lab (JLab). This is done by studying the reaction, gammap → fJp → KS0 KS0p → 2(pi +pi-)p using data from the g12 experiment. A clear peak is seen at 1500 MeV in the background subtracted data. This is enhanced if the momentum transfer is restricted to be less than 1 GeV2. Comparing with simulations, it is seen that this peak is associated with t channel production mechanism. The f 2'(1525) has a mass of 1525 MeV and a width of 73 MeV, and hence there is a possibility of it contributing to the peak observed in our data. A moments analysis seems to suggest some presence of a D wave, however, the low acceptance at forward and backward angles prohibits a definitive conclusion.
Unconstrained Hamiltonian formulation of low energy SU(3) Yang-Mills quantum theory
Pavel, Hans-Peter
2012-01-01
An unconstrained Hamiltonian formulation of the SU(3) Yang-Mills quantum mechanics of spatially constant fields is given using the method of minimal embedding of SU(2) into SU(3) by Kihlberg and Marnelius. Using a canonical transformation of the gluon fields to a new set of adapted coordinates (a non-standard type polar decomposition), which Abelianizes the Non-Abelian Gauss law constraints to be implemented, the corresponding unconstrained Hamiltonian and total angular momentum are derived. This reduces the colored spin-1 gluons to unconstrained colorless spin-0, spin-1, spin-2 and spin-3 glueball fields. The obtained unconstrained Hamiltonian is then rewritten into a form, which separates the rotational from the scalar degrees of freedom. It is shown that the chromomagnetic potential has classical zero-energy valleys for two arbitrarily large classical glueball fields, which are the unconstrained analogs of the well-known "constant Abelian fields". On the quantum level, practically all glueball excitation e...
A Quirky Probe of Neutral Naturalness
Chacko, Zackaria; Verhaaren, Christopher B
2015-01-01
We consider the signals arising from top partner pair production at the LHC as a probe of theories of Neutral Naturalness. We focus on scenarios in which the top partners carry electroweak charges, such as Folded SUSY or the Quirky Little Higgs. In this class of theories the top partners are charged under a mirror color group whose lightest states are hidden glueballs. The top partners, once produced, form a quirky bound state that de-excites promptly and annihilates into hidden glueballs. These glueballs can decay through mixing with the Higgs, giving rise to striking displaced signatures at the LHC. We show that the displaced signals arising from top partner pair production constitute the primary discovery channel for this class of theories in most regions of parameter space.
Photoproduction of scalar mesons at CLAS
Chandavar, Shloka; Hicks, Kenneth; Weygand, Dennis; CLAS Collaboration
2013-10-01
A single gluon, which carries color charge, cannot exist independently outside a hadron. Lattice QCD calculations in pure SU(3), however, predict the existence of glueballs which are bound states of two or more gluons. In the real world, the challenge to identify glueballs experimentally is the fact they mix with meson states. The f0 (1500) is one of several candidates for the lightest glueball, with JPC =0++ . We investigate the presence of this particle in photoproduction by analyzing the reaction γp -->fJ p -->KS0KS0 p --> 2 (π+π-) p . This reaction was studied using data from the g12 experiment performed using the CLAS detector at Jefferson Lab. A preliminary partial wave analysis, performed on the KS0KS0 invariant mass spectrum, will be presented. These results update those presented for this reaction channel at previous conferences. This work is supported by grant from NSF.
Oddballs and a Low Odderon Intercept
Llanes-Estrada, F J; Cotanch, S R; Llanes-Estrada, Felipe J.; Bicudo, Pedro; Cotanch, Stephen R.
2006-01-01
We report an odderon Regge trajectory emerging from a field theoretical Coulomb gauge QCD model for the odd signature JPC (P=C= -1) glueball states (oddballs). The trajectory intercept is clearly smaller than the pomeron and even the omega trajectory's intercept which provides an explanation for the nonobservation of the odderon in high energy scattering data. To further support this result we compare to glueball lattice data and also perform calculations with an alternative model based upon an exact Hamiltonian diagonalization for three constituent gluons.
Hagedorn spectrum and equation of state of Yang-Mills theories
Caselle, Michele; Panero, Marco
2015-01-01
We present a novel lattice calculation of the equation of state of SU(2) Yang-Mills theory in the confining phase. We show that a gas of massive, non-interacting glueballs describes remarkably well the results, provided that a bosonic closed-string model is used to derive an exponentially growing Hagedorn spectrum for the heavy glueball states with no free parameters. This effective model can be applied to SU(3) Yang-Mills theory and the theoretical prediction agrees nicely with the lattice results reported by Bors\\'anyi et al. in JHEP 07 (2012) 056.
Oddballs and a Low Odderon Intercept
Llanes-Estrada, Felipe J.; /Madrid U.; Bicudo, Pedro; /Lisbon U. /Lisbon, IST; Cotanch, Stephen R.; /North Carolina State U.
2005-07-27
The authors report an odderon Regge trajectory emerging from a field theoretical Coulomb gauge QCD model for the odd signature J{sup PC} (P = C = -1) glueball states (oddballs). The trajectory intercept is clearly smaller than the pomeron and even the {omega} trajectory's intercept which provides an explanation for the nonobservation of the odderon in high energy scattering data. To further support this result we compare to glueball lattice data and also perform calculations with an alternative model based upon an exact Hamiltonian diagonalization for three constituent gluons.
Laurent Guiraud
1999-01-01
Detail of one of the magnets on the Common Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) experiment. COMPASS studies the structure of composite particles which interact via the strong force, called hadrons. These have a complicated internal structure due to the nature of their force carriers, gluons, which can form self interacting bunches called glueballs.
Performance of Cooled PWO Scintillators With Signal-Sampling Readout
Lohner, H.; Guliyev, E.; Kavatsyuk, M.; Lemmens, P. J. J.; Tambave, G.
2012-01-01
For the investigation of the charmonium spectrum, yet undiscovered charm-meson states and glueballs, the PANDA detector will be employed at the future FAIR facility. PANDA will contain an electromagnetic calorimeter composed of PbWO4 (PWO) crystals that are cooled to -25 degrees C and coupled to lar
New results in meson spectroscopy from the crystal barrel experiment
Meyer, C.A. [Carnegie Mellon Univ., Pittsburgh, PA (United States)
1994-04-01
Recent observations by the Crystal Barrel experiment of two scalar resonances, f{sub o}(1365) and a{sub o}(1450) have allowed the authors to clarify the members of the scalar nonet. In addition, a third scalar, f{sub o}(1500), appears to be supernumerary, and is a candidate for the scalar glueball expected near 1500 MeV.
Cartwright, Susan; Lehto, Mark [University of Sheffield Department of Physics, Sheffield S3 7RH (United Kingdom); Seymour, Michael H.; Close, Frank; Wright, Alison [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Affholderbach, Klaus; Cowan, Glen [Universitaet Siegen, Fachbereich Physik, D-57068 Siegen (Germany); Finch, Alex [University of Lancaster, Lancaster LA1 4YB (United Kingdom); Lauber, Jan [University College London, Gower Street, London WC1E 6BT (United Kingdom)
1998-02-01
The working group on two-photon physics concentrated on three main subtopics: modelling the hadronic final state of deep inelastic scattering on a photon; unfolding the deep inelastic scattering data to obtain the photon structure function; and resonant production of exclusive final states, particularly of glueball candidates. In all three areas, new results were presented. (author)
Finite-Temperature Phase Structure in the Chiral σ-ω Model with Dilatons
ZHANG Xiao-Bing ZHANG Xiao-Bing; LI Xue-Qian; NING Ping-Zhi
2000-01-01
We investigate the finite-temperature phase structure in a scaled chiral model which includes the dilaton (glueball) field. It is shown that hot nuclear matter undergoes a discontinuous transition in the mean field of scalar mesons as well as the Lee-Wick abnormal transition. The corresponding behavior of the gluon condensate during the chiral phase transition is also studied.
Front-End Electronics and Feature-Extraction Algorithm for the PANDA Electromagnetic Calorimeter
Kavatsyuk, M.; Guliyev, E.; Lemmens, P. J. J.; Löhner, H.; Poelman, T. P.; Tambave, G.; Wang, YF; Hu, T
2011-01-01
The PANDA collaboration at FAIR, Germany, will employ antiproton annihilations to investigate yet undiscovered charm-mesons and glueballs aiming to unravel the origin of hadronic masses. A multi-purpose detector for tracking, calorimetry and particle identification is presently being developed to
Density of Saturated Nuclear Matter at Large $N_{c}$ and Heavy Quark Mass Limits
Adhikari, Prabal; Datta, Ishaun
2013-01-01
We exhibit the existence of stable, saturated nuclear matter in the large $N_{c}$ and heavy quark mass limits of QCD. In this limit, baryons (with the same spin flavor structure) interact at leading order in $N_{c}$ via a repulsive interaction due to the Pauli exclusion principle and at subleading order in $1/N_c$ via the exchange of glueballs. Assuming that the lightest glueball is a scalar, which implies that the subleading baryon interaction is attractive, we find that nuclear matter saturates since the subleading attractive interaction is longer ranged than the leading order repulsive one. We find that the saturated matter is in the form of a crystal with either a face-centered cubic or a hexagonal-close-packed symmetry with baryon densities of $\\mathcal{O}((\\, \\tilde{\\alpha}_{s} m_q (\\ln (N_{c}m_{q}\\Lambda_{\\textrm{QCD}}^{-1}))^{-1})^3 )$. Remarkably, the leading order expression for the density of saturated nuclear matter is independent of the lighest glueball mass and scalar-glueball-baryon coupling in...
Dyons in Nonabelian Born-Infeld Theory
Balaz, A; Radovanovic, Voja
2002-01-01
We analyze a nonabelian extension of Born--Infeld action for the SU(2) group. In the class of spherically symmetric solutions we find that, besides the Gal'tsov--Kerner glueballs, only the analytic dyons have finite energy. The presented analytic and numerical investigation excludes the existence of pure magnetic monopoles of 't Hooft--Polyakov type.
Heisenberg's Universal (lns)**2 Increase of Total Cross Sections
Dosch, H G; Nicolescu, Basarab
2003-01-01
The (lns)**2 behaviour of total cross-sections, first obtained by Heisenberg 50 years ago, receives now increased interest both on phenomenological and theoretical levels. In this paper we present a modification of the Heisenberg's model in connection with the presence of glueballs and we show that it leads to a realistic description of all existing hadron total cross-section data.
Progress toward identification of gluonic states
Chanowitz, M.S.
1987-05-29
Progress in the last two years toward identification of gluonic states is reviewed. Discovery of additional pseudoscalars tends to confirm the glueball interpretation of iota(1460). A variety of evidence indicates new physics in the J = 1 channel in the E mass region. 65 refs., 1 tab.
Gluonic Excitations' Millennial Finale
Page, P R
2000-01-01
We provide an overview of theoretical developments on hybrid mesons and glueballs in the last year at this turn of the millenium conference. Cracks in potential models of conventional mesons are developing. Hybrid meson adiabatic surfaces have been calculated and interpreted, experimental J^PC exotics have hybrid meson, four-quark state or non-resonant interpretations, and the strong decay mechanism of hybrids has been studied. All theoretical progress on hybrid mesons in the last year is mentioned. Overall features of glueballs are visited: decays and the successes of the large N_c limit. Two promising experimental areas are mentioned: charmonium hybrids at B-factories and s sbar hybrids at Jefferson Lab.
Inclusive K(S);(0)K(S);(0) resonance production in ep collisions at HERA.
Chekanov, S; Derrick, M; Magill, S; Musgrave, B; Nicholass, D; Repond, J; Yoshida, R; Mattingly, M C K; Antonioli, P; Bari, G; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cindolo, F; Corradi, M; Iacobucci, G; Margotti, A; Nania, R; Polini, A; Antonelli, S; Basile, M; Bindi, M; Cifarelli, L; Contin, A; De Pasquale, S; Sartorelli, G; Zichichi, A; Bartsch, D; Brock, I; Hartmann, H; Hilger, E; Jakob, H-P; Jüngst, M; Nuncio-Quiroz, A E; Paul, E; Samson, U; Schönberg, V; Shehzadi, R; Wlasenko, M; Brook, N H; Heath, G P; Morris, J D; Capua, M; Fazio, S; Mastroberardino, A; Schioppa, M; Susinno, G; Tassi, E; Kim, J Y; Ibrahim, Z A; Kamaluddin, B; Wan Abdullah, W A T; Ning, Y; Ren, Z; Sciulli, F; Chwastowski, J; Eskreys, A; Figiel, J; Galas, A; Gil, M; Olkiewicz, K; Stopa, P; Zawiejski, L; Adamczyk, L; Bołd, T; Grabowska-Bołd, I; Kisielewska, D; Lukasik, J; Przybycień, M; Suszycki, L; Kotański, A; Słomiński, W; Behrens, U; Blohm, C; Bonato, A; Borras, K; Ciesielski, R; Coppola, N; Fang, S; Fourletova, J; Geiser, A; Göttlicher, P; Grebenyuk, J; Gregor, I; Haas, T; Hain, W; Hüttmann, A; Januschek, F; Kahle, B; Katkov, I I; Klein, U; Kötz, U; Kowalski, H; Lobodzinska, E; Löhr, B; Mankel, R; Melzer-Pellmann, I-A; Miglioranzi, S; Montanari, A; Namsoo, T; Notz, D; Parenti, A; Rinaldi, L; Roloff, P; Rubinsky, I; Santamarta, R; Schneekloth, U; Spiridonov, A; Szuba, D; Szuba, J; Theedt, T; Wolf, G; Wrona, K; Yagües Molina, A G; Youngman, C; Zeuner, W; Drugakov, V; Lohmann, W; Schlenstedt, S; Barbagli, G; Gallo, E; Pelfer, P G; Bamberger, A; Dobur, D; Karstens, F; Vlasov, N N; Bussey, P J; Doyle, A T; Dunne, W; Forrest, M; Rosin, M; Saxon, D H; Skillicorn, I O; Gialas, I; Papageorgiu, K; Holm, U; Klanner, R; Lohrmann, E; Schleper, P; Schörner-Sadenius, T; Sztuk, J; Stadie, H; Turcato, M; Foudas, C; Fry, C; Long, K R; Tapper, A D; Matsumoto, T; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Barakbaev, A N; Boos, E G; Pokrovskiy, N S; Zhautykov, B O; Aushev, V; Borodin, M; Kadenko, I; Kozulia, A; Libov, V; Lisovyi, M; Lontkovskyi, D; Makarenko, I; Sorokin, Iu; Verbytskyi, A; Volynets, O; Son, D; de Favereau, J; Piotrzkowski, K; Barreiro, F; Glasman, C; Jimenez, M; Labarga, L; Del Peso, J; Ron, E; Soares, M; Terrón, J; Zambrana, M; Corriveau, F; Liu, C; Schwartz, J; Walsh, R; Zhou, C; Tsurugai, T; Antonov, A; Dolgoshein, B A; Gladkov, D; Sosnovtsev, V; Stifutkin, A; Suchkov, S; Dementiev, R K; Ermolov, P F; Gladilin, L K; Golubkov, Yu A; Khein, L A; Korzhavina, I A; Kuzmin, V A; Levchenko, B B; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Zotkin, D S; Abt, I; Caldwell, A; Kollar, D; Reisert, B; Schmidke, W B; Grigorescu, G; Keramidas, A; Koffeman, E; Kooijman, P; Pellegrino, A; Tiecke, H; Vázquez, M; Wiggers, L; Brümmer, N; Bylsma, B; Durkin, L S; Lee, A; Ling, T Y; Allfrey, P D; Bell, M A; Cooper-Sarkar, A M; Devenish, R C E; Ferrando, J; Foster, B; Korcsak-Gorzo, K; Oliver, K; Robertson, A; Uribe-Estrada, C; Walczak, R; Bertolin, A; Dal Corso, F; Dusini, S; Longhin, A; Stanco, L; Bellan, P; Brugnera, R; Carlin, R; Garfagnini, A; Limentani, S; Oh, B Y; Raval, A; Ukleja, J; Whitmore, J J; Iga, Y; D'Agostini, G; Marini, G; Nigro, A; Cole, J E; Hart, J C; Abramowicz, H; Ingbir, R; Kananov, S; Levy, A; Stern, A; Kuze, M; Maeda, J; Hori, R; Kagawa, S; Okazaki, N; Shimizu, S; Tawara, T; Hamatsu, R; Kaji, H; Kitamura, S; Ota, O; Ri, Y D; Costa, M; Ferrero, M I; Monaco, V; Sacchi, R; Solano, A; Arneodo, M; Ruspa, M; Fourletov, S; Martin, J F; Stewart, T P; Boutle, S K; Butterworth, J M; Gwenlan, C; Jones, T W; Loizides, J H; Wing, M; Brzozowska, B; Ciborowski, J; Grzelak, G; Kulinski, P; Luzniak, P; Malka, J; Nowak, R J; Pawlak, J M; Tymieniecka, T; Ukleja, A; Zarnecki, A F; Adamus, M; Plucinski, P; Eisenberg, Y; Hochman, D; Karshon, U; Brownson, E; Danielson, T; Everett, A; Kçira, D; Reeder, D D; Ryan, P; Savin, A A; Smith, W H; Wolfe, H; Bhadra, S; Catterall, C D; Cui, Y; Hartner, G; Menary, S; Noor, U; Standage, J; Whyte, J
2008-09-12
Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.
Towards a Theory of the QCD String
CERN. Geneva
2017-01-01
I will review recent progress in understanding the dynamics of confining strings in non-supersymmetric gluodynamics in 3 and 4 space time dimensions. I will argue that the present lattice data allows to formulate a non-trivial straw man Ansatz for the worldsheet theory of long confining strings. According to this Ansatz, pure gluodynamics in 3D is described by a non-critical bosonic string theory without any extra local worldsheet degrees of freedom. I argue that the Ansatz allows to fix quantum numbers of (almost) all glueball states. I confront the resulting predictions with the properties of approximately 39 lightest glueball states observed on a lattice and find a good agreement.
Entanglement Entropy of the Klebanov-Strassler with dynamical flavors
Georgiou, George
2015-01-01
We present a detailed study of the Entanglement Entropy for the confining Klebanov-Strassler background coupled to a large number of dynamical flavors in the Veneziano limit. As we vary the number of the massless flavors the behavior of the entropy strongly depends on the way we fix the integration constant of the warp factor, that is related to the glueball scale. In the case of massive flavors, the mass of the flavor branes introduces another scale in the background and the entropy undergoes two first order phase transitions. The competition between the glueball and the quark scales will lead to a critical point where one of the phase transitions degenerates to a second order one. We have calculated the critical exponents and have found that they are independent of the number of flavors and different from the mean filed theory expectations.
Kuperstein, S.; Sonnenschein, J.
2004-11-01
We study certain properties of the low energy regime of a theory which resembles four dimensional YM theory in the framework of a non-critical holographic gravity dual. We use for the latter the near extremal AdS6 non-critical SUGRA. We extract the glueball spectra that associates with the fluctuations of the dilaton, one form and the graviton and compare the results to those of the critical near extremal D4 model and lattice simulations. We show an area law behavior for the Wilson loop and screening for the 't Hooft loop. The Luscher term is found to be -(3π/24L). We derive the Regge trajectories of glueballs associated with the spinning folded string configurations.
Composite Inflation in the light of 2015 Planck data
Channuie, Phongpichit
2016-08-01
In this work, we examine cosmological constraints on models of composite inflation based on the slow-roll approximation by using the recent Planck measurement. We compare the spectral index of curvature perturbation (and its running) and the tensor-to-scalar ratio predicted by such models with Planck 2015 data. We find that the predictions of technicolor inflation are nicely consistent with the Planck analysis. Moreover, the predictions from the second model, glueball inflation, are in good agreement with the Planck data at 2σC.L. However, the final two models, super glueball inflation and orientifold inflation, favor only the rather large value of the tensor-to-scalar ratio of which the predictions are in tension with the Planck analysis.
Planar Gravitational Corrections For Supersymmetric Gauge Theories
Dijkgraaf, R; Ooguri, H; Vafa, C; Zanon, D
2004-01-01
In this paper we discuss the contribution of planar diagrams to gravitational F-terms for N=1 supersymmetric gauge theories admitting a large N description. We show how the planar diagrams lead to a universal contribution at the extremum of the glueball superpotential, leaving only the genus one contributions, as was previously conjectured. We also discuss the physical meaning of gravitational F-terms.
Strongly interacting matter from holographic QCD model
Chen, Yidian; Huang, Mei
2016-01-01
We introduce the 5-dimension dynamical holographic QCD model, which is constructed in the graviton-dilaton-scalar framework with the dilaton background field $\\Phi$ and the scalar field $X$ responsible for the gluodynamics and chiral dynamics, respectively. We review our results on the hadron spectra including the glueball and light meson spectra, QCD phase transitions and transport properties in the framework of the dynamical holographic QCD model.
Lindenbaum, S.J.; Samuel, S.
1993-09-01
A critical investigation of non-perturbative QCD require investigating glueballs, search for a Quark Gluon Plasma (OGP), and search for strangelets. In the glueball area the data obtained (E- 881) at 8 GeV/c were analyzed for {pi}{sup {minus}} + p {yields} {phi}{phi}n (OZI forbidden), {phi}K{sup +}K{sup {minus}}n (OZI allowed), K{sup {minus}}p {yields} {phi}{phi}({Lambda}{Sigma}) (OZI allowed), and {bar p}p {yields} {phi}{phi} {yields} {phi}{phi}{pi}{sup 0} (OZI forbidden), {phi}K{sup +}K{sup {minus}}{pi}{sup 0} (OZI allowed). By comparing the OZI forbidden (glueball filter reactions) with the OZI allowed and previous 22 GeV/c {pi}{sup {minus}}p {yields} {phi}{phi}n or {phi}K{sup +}K{sup {minus}}n data a further critical test of the so far unsuccessfully challenged hypothesis that our g{sup T}(2010), g{sub T}{prime}(2300) and g{sub T}{double_prime}(2340) all with I{sup G}J{sup PC} = 0{sup +}2{sup ++} are produced by 1-3 2{sup ++} glueballs will be made. In the QGP search with a large-solid-angle TPC a good {Xi} signal was observed. The ratio of {Xi} to single strange quark particles such as {lambda} is a better indication of strangeness enhancement in QGP formation. The data indicate enhancement by a factor {approx} 2 over cascade model (corrected to observed strangeness) predictions, but it is definitely far from conclusive at this stage since the result is model dependent. Double {lambda} topologies of the type needed to discover light strangelets in the nanosecond lifetime region were found. In addition, research has been accomplished in three main areas: bosonic technicolor and strings, buckministerfullerene C{sub 60} and neutrino oscillations in a dense neutrino gas.
2006-01-01
Artistic view of the 60 m long Common Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) experiment. COMPASS takes beams from the SPS accelerator at CERN. This beam enters from the lower left and passes through the cylindrical target solenoid. COMPASS is used to study the internal structure of hadrons (composite particles interacting via the strong force) by looking at a property called spin and a phenomenon known as glueballs.
Lattice energy sum rules and the trace anomaly
Rothe, Heinz J.
1995-01-01
We show that the additional contribution to the Michael lattice energy sum rule for the static quark-antiquark potential, pointed out recently, can be identified with the contribution to the field energy arising from the trace anomaly of the energy momentum tensor. We also exlicitely exhibit the anomalous contribution to the field energy in the sum rule for the glueball mass obtained recently by Michael.
K\\"allen-Lehman Representation and the Gluon Propagator
Frasca, Marco
2007-01-01
We exploit the Kallen-Lehman representation of the two-point Wightman function to prove that the gluon propagator cannot go to zero in the infrared limit. We are able to derive also the functional form of it. This means that current results on the lattice can be used to derive the scalar glueball spectrum to be compared both with experiments and different aimed lattice computations.
Vector meson electroproduction in QCD
LU Juan; CAI Xian-Hao; ZHOU Li-Juan
2012-01-01
Based on the generalized QCD vector meson dominance model,we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model.Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for p,ω and φ meson electroproduction in this paper.Since gluons interact among themselves (self-interaction),two gluons can form a glueball with quantum numbers IG,JPC =0+,2++,decay width Γt ≈ 100 MeV,and mass of mG=2.23 GeV.The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C =-1,called the Odderon.The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon.Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully,which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton.It should be emphasized that our mechanism is different from the theoretical framework of Block et al.We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies,as well as for searching for new particles such as tensor glueballs and Odderons,which have been predicted by QCD and the color glass condensate model (CGC).Therefore,in return,it can test the validity of QCD and the CGC model.
Vector meson electroproduction in QCD
Lu, Juan; Cai, Xian-Hao; Zhou, Li-Juan
2012-08-01
Based on the generalized QCD vector meson dominance model, we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model. Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for ρ, ω and varphi meson electroproduction in this paper. Since gluons interact among themselves (self-interaction), two gluons can form a glueball with quantum numbers IG, JPC = 0+,2++, decay width Γt ≈ 100 MeV, and mass of mG = 2.23 GeV. The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C = -1, called the Odderon. The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon. Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully, which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton. It should be emphasized that our mechanism is different from the theoretical framework of Block et al. We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies, as well as for searching for new particles such as tensor glueballs and Odderons, which have been predicted by QCD and the color glass condensate model (CGC). Therefore, in return, it can test the validity of QCD and the CGC model.
DeGrand, T. [Univ. of Colorado, Boulder, CO (United States). Dept. of Physics
1997-06-01
These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1: Basic techniques for QCD and results for hadron spectroscopy using the simplest discretizations; lecture 2: Improved actions--what they are and how well they work; lecture 3: SLAC physics from the lattice-structure functions, the mass of the glueball, heavy quarks and {alpha}{sub s} (M{sub z}), and B-{anti B} mixing. 67 refs., 36 figs.
Gluonic Hadrons and Charmless B Decays
Close, Francis Edwin; Page, P R; Veseli, S; Yamamoto, H
1998-01-01
Hybrid charmonium with mass ~4 GeV could be produced via a c c.bar color-octet component in b->c c.bar s. These states could be narrow and could have a significant branching ratio to light hadrons, perhaps enhanced by glueballs. Decays to gluonic hadrons could make a sizable contribution to B->no charm decays. Experimental signatures and search strategies are discussed.
Nicolescu, B
2004-01-01
The ln**2 behaviour of total cross sections, first obtained by Heisenberg 50 years ago, receives now increased interest both on phenomenological and theoretical levels. We present a modification of the Heisenberg's model in connection with the presence of glueballs and we show that it leads to a realistic description of all existing hadron total cross-section data, in agreement with the COMPETE analysis.
A study of the centrally produced $\\phi \\phi$ system in pp interactions at 450 GeV/c
Barberis, D
1998-01-01
The reaction pp to pfps(K+K-K+K-) in which the K+K-K+K- system is centrally produced has been studied at 450 GeV/c. Phi phi production has been found to dominate this reaction and is compatible with being produced by double Pomeron exchange. An angular analysis of the phi phi system favours JPC = 2++ and its dPT dependence is similar to that observed for glueball candidates.
Lenz, F
2009-01-01
By superposition of regular gauge instantons or merons, ensembles of gauge fields are constructed which describe the confining phase of SU(2) Yang-Mills theory. Various properties of the Wilson loops, the gluon condensate and the topological susceptibility are found to be in qualitative agreement with phenomenology or results of lattice calculations. Limitations in the application to the glueball spectrum and small size Wilson loops are discussed.
Holography inspired stringy hadrons
Sonnenschein, Jacob
2017-01-01
Holography inspired stringy hadrons (HISH) is a set of models that describe hadrons: mesons, baryons and glueballs as strings in flat four dimensional space-time. The models are based on a "map" from stringy hadrons of holographic confining backgrounds. In this note we review the "derivation" of the models. We start with a brief reminder of the passage from the AdS5 ×S5 string theory to certain flavored confining holographic models. We then describe the string configurations in holographic backgrounds that correspond to a Wilson line, a meson, a baryon and a glueball. The key ingredients of the four dimensional picture of hadrons are the "string endpoint mass" and the "baryonic string vertex". We determine the classical trajectories of the HISH. We review the current understanding of the quantization of the hadronic strings. We end with a summary of the comparison of the outcome of the HISH models with the PDG data about mesons and baryons. We extract the values of the tension, masses and intercepts from best fits, write down certain predictions for higher excited hadrons and present attempts to identify glueballs.
Asymptotic Freedom versus Open/Closed Duality in Large-N QCD
Bochicchio, Marco
2016-01-01
The solution of the large-N 't Hooft limit of QCD is universally believed to be a String Theory of Closed Strings in the Glueball Sector and of Open Strings in the Meson Sector. Yet, we prove a no-go theorem, that the large-N limit of QCD with massless quarks, or more generally, that the large-N limit of a vast class of confining, i.e. with a Mass Gap in the Glueball Sector, asymptotically-free Gauge Theories coupled to matter fields with no mass scale in perturbation theory cannot be a canonically-defined String Theory of Closed and Open Strings, i.e. admitting Open/Closed Duality. The no-go theorem occurs because Open/Closed Duality, implying that the ultraviolet divergences of annulus diagrams in the Open Sector arise from infrared divergences of tadpoles of massless particles in the Closed Sector, turns out to be incompatible with the existence of the Mass Gap in the Glueball Sector of confining asymptotically-free theories with no mass scale in perturbation theory in which, as for example in QCD, the fir...
Phase transition for gluon field: a qualitative analysis
Dzhunushaliev, Vladimir
2012-01-01
The phase transition for SU(3) gauge field (without quarks) is considered. It is shown that the phase transition is due to the fact that at high temperatures the partition function should be calculated as for a gas of gluons, whereas at low temperatures as the sum over energy levels of correlated quantum states of SU(3) gauge field. A correlated quantum state for strongly interacting fields is defined as a nonperturbative quantum state of strongly interacting fields. The energy spectrum of these quantum states are discrete one. A lower bound of the phase transition temperature by comparing of the average energy for the perturbative and nonperturbative regimes is estimated (for glueball being in thermal equilibrium with the thermostat). It is shown that this quantity is associated with a mass gap. In a scalar model of glueball its energy is calculated. It is shown that this energy is the mass gap. If we set the glueball mass $ \\approx 1.5 \\cdot 10^3$ Mev then it is found that the corresponding value of couplin...
A quirky probe of neutral naturalness
Chacko, Zackaria; Curtin, David; Verhaaren, Christopher B.
2016-07-01
We consider the signals arising from top partner pair production at the LHC as a probe of theories of neutral naturalness. We focus on scenarios in which top partners carry electroweak charges, such as folded supersymmetry or the quirky little Higgs. In this class of theories the top partners are pair produced as quirky bound states, since they are charged under a mirror color group whose lightest states are hidden glueballs. The quirks promptly de-excite and annihilate into glueballs, which decay back to Standard Model fermions via Higgs mixing. This can give rise to spectacular signatures at the LHC, such displaced decays, or high-multiplicity prompt production of many hard b ¯b or τ+τ- pairs. We show that signals arising from top partner pair production constitute the primary discovery channel for this class of theories in most regions of parameter space, and might provide the only experimental probe of scenarios with sub-cm glueball decay lengths. The measurement of top partner masses and couplings, which could be used to test the neutral naturalness mechanism directly, is also a tantalizing possibility.
Tadpole-improved SU(2) lattice gauge theory
Shakespeare, N H; Shakespeare, Norman H.; Trottier, Howard D.
1999-01-01
A comprehensive analysis of tadpole-improved SU(2) lattice gauge theory is made. Simulations are done on isotropic and anisotropic lattices, with and without improvement. Two tadpole renormalization schemes are employed, one using average plaquettes, the other using mean links in Landau gauge. Simulations are done with spatial lattice spacings $a_s$ in the range of about 0.1--0.4 fm. Results are presented for the static quark potential, the renormalized lattice anisotropy $a_t/a_s$ (where $a_t$ is the ``temporal'' lattice spacing), and for the scalar and tensor glueball masses. Tadpole improvement significantly reduces discretization errors in the static quark potential and in the scalar glueball mass, and results in very little renormalization of the bare anisotropy that is input to the action. We also find that tadpole improvement using mean links in Landau gauge results in smaller discretization errors in the scalar glueball mass (as well as in the static quark potential), compared to when average plaquett...
Predictions of High Energy Experimental Results
Comay E.
2010-10-01
Full Text Available Eight predictions of high energy experimental results are presented. The predictions contain the $Sigma ^+$ charge radius and results of two kinds of experiments using energetic pionic beams. In addition, predictions of the failure to find the following objects are presented: glueballs, pentaquarks, Strange Quark Matter, magnetic monopoles searched by their direct interaction with charges and the Higgs boson. The first seven predictions rely on the Regular Charge-Monopole Theory and the last one relies on mathematical inconsistencies of the Higgs Lagrangian density.
Path Integral Monte Carlo Approach to the U(1) Lattice Gauge Theory in (2+1) Dimensions
Loan, M; Sloggett, C; Hamer, C; Loan, Mushtaq; Brunner, Michael; Sloggett, Clare; Hamer, Chris
2003-01-01
Path Integral Monte Carlo simulations have been performed for U(1) lattice gauge theory in (2+1) dimensions on anisotropic lattices. We extract the static quark potential, the string tension and the low-lying "glueball" spectrum. The Euclidean string tension and mass gap decrease exponentially at weak coupling in excellent agreement with the predictions of Polyakov and G{\\" o}pfert and Mack, but their magnitudes are five times bigger than predicted. Extrapolations are made to the extreme anisotropic or Hamiltonian limit, and comparisons are made with previous estimates obtained in the Hamiltonian formulation.
Dynamical corrections to the anomalous holographic soft-wall model: the pomeron and the odderon
Capossoli, Eduardo Folco [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Colegio Pedro II, Departamento de Fisica, Rio de Janeiro, RJ (Brazil); Li, Danning [Institute of Theoretical Physics, Chinese Academy of Science (ITP, CAS), Beijing (China); Boschi-Filho, Henrique [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)
2016-06-15
In this work we use the holographic soft-wall AdS/QCD model with anomalous dimension contributions coming from two different QCD beta functions to calculate the masses of higher spin glueball states for both even and odd spins and their Regge trajectories, related to the pomeron and the odderon, respectively. We further investigate this model taking into account dynamical corrections due to a dilaton potential consistent with the Einstein equations in five dimensions. The results found in this work for the Regge trajectories within the anomalous soft-wall model with dynamical corrections are consistent with those present in the literature. (orig.)
Kajantie, K; Vepsalainen, M; Vuorinen, Aleksi
2011-01-01
We use AdS/QCD duality to compute the finite temperature Green's function G(omega,k;T) of the shear operator T_12 for all omega,k in hot Yang-Mills theory. The goal is to assess how the existence of scales like the transition temperature and glueball masses affects the correlator computed in the scalefree conformal N=4 supersymmetric Yang-Mills theory. We observe sizeable effects for T close to T_c which rapidly disappear with increasing T. Quantitative agreement of these predictions with future lattice Monte Carlo data would suggest that QCD matter in this temperature range is strongly interacting.
Solitons in Non-Abelian Born-Infeld Theory
Galtsov, D V
2001-01-01
Born-Infeld generalization of the Yang-Mills action suggested by the superstring theory gives rise to modification of previously known as well as to some new classical soliton solutions. Earlier it was shown that within the model with the usual trace over the group generators classical glueballs exist which form an infinite sequence similar to the Bartnik-McKinnon family of the Einstein-Yang-Mills solutions. Here we give the generalization of this result to the 'realistic' model with the symmetrized trace and show the existence of excited monopoles (in presence of triplet Higgs) which can be regarded as a non-linear superposition of monopoles and sphalerons.
Meson Structure in a Relativistic Many-Body Approach
Llanes-Estrada, F J; Llanes-Estrada, Felipe J.; Cotanch, Stephen R.
2000-01-01
Results from an extensive relativistic many-body analysis utilizing a realistic effective QCD Hamiltonian are presented for the meson spectrum. A comparative numerical study of the BCS, TDA and RPA treatments provides new, significant insight into the condensate structure of the vacuum, the chiral symmetry governance of the pion and the meson spin, orbital and flavor mass splitting contributions. In contrast to a previous glueball application, substantial quantitative differences are computed between TDA and RPA for the light quark sector with the pion emerging as a Goldstone boson only in the RPA.
Electromagnetic proton form factors: perspectives for PANDA
Tomasi-Gustafsson Egle
2014-03-01
Full Text Available The PANDA collaboration studies fundamental aspects of the strong interaction in the transition region between non-perturbative and perturbative QCD, investigating charmonium spectroscopy, hybrids and glueballs, hypernuclei, light and heavy meson production with antiproton beams. In this contribution we focus on leptonic final channels which give access to nucleon electromagnetic form factors. The expected precision on the electric and magnetic form factors of the proton in the time-like region and the radiative corrections to be applied to the data are discussed.
Variational Calculation in SU(3) Lattice Gauge Theory
YANG Chun; ZHANG Qi-Ren; GAO Chun-Yuan
2001-01-01
Using the Hamiltonian lattice gauge theory, we perform some variational calculations to obtain the ground-state energy of SU(3) gauge field and scalar (0++) glueball mass. The agreement of our data with the strong and weak expansion results in the corresponding limits indicates that this method can provide us with reliable information in the most interesting medium region. The trial wavefunction used in our variational method is also proven to be a good first approximation of the ground-state of the SU(3) gauge field. Upgrading this function according to correlations of adjacent plaquettes may mean better results.
Hadron spectroscopy in double pomeron exchange experiments
Albrow, Michael G.
2017-03-01
Central exclusive production in hadron-hadron collisions at high energies, for example p + p → p + X + p, where the + represents a large rapidity gap, is a valuable process for spectroscopy of mesonic states X. At collider energies the gaps can be large enough to be dominated by pomeron exchange, and then the quantum numbers of the state X are restricted. Isoscalar JPC = 0++ and 2++ mesons are selected, and our understanding of these spectra is incomplete. In particular, soft pomeron exchanges favor gluon-dominated states such as glueballs, which are expected in QCD but not yet well established. I will review some published data.
Page, P R
2001-01-01
Lattice QCD gives reliable predictions for hybrid charmonium and multi-GeV glueball masses. Proton-antiproton annihilation may offer an excellent opportunity for the first observation of these states. There are two distinct possible programs: The search for J^PC-exotic and non-J^PC-exotic states. The latter program represents substantially higher cross sections and does not absolutely require partial wave analysis, two very attractive features. The program can be performed with a varying pbar energy <10 GeV and a fixed target.
Pomeron and odderon Regge trajectories from a dynamical holographic model
Eduardo Folco Capossoli
2016-09-01
Full Text Available In this work we use gauge/string dualities and a dynamical model that takes into account dynamical corrections to the metric of the anti de Sitter space due to a quadratic dilaton field and calculate the masses of even and odd spin glueball states with P=C=+1, and P=C=−1, respectively. Then we construct the corresponding Regge trajectories which are associated with the pomeron for even states with P=C=+1, and with the odderon for odd states with P=C=−1. We compare our results with those coming from experimental data as well as other models.
Overview of the status/results in the exotics sector
Shen Chengping
2016-01-01
Full Text Available Many exotic hadronic states beyond the conventional quark model (called char-moniumlike/bottomoniumlike states or XYZ particles were found in the B-factories or energy scans of the cross sections of e+e− annhilation into conventional quarkonia and light hadrons. Their nature properties were proposed including glueballs, hybrids, multi-quark states, hadron molecules, etc. Dramatic progress was made in the study of the them after the running of the B-factories. In this report, I present the most recent results on the XYZ results from Belle experiment.
A gravity dual of ultra-slow roll inflation
Lilia Anguelova
2016-10-01
Full Text Available We study time-dependent deformations of a certain class of backgrounds in type IIB supergravity. These backgrounds are solutions of a five-dimensional consistent truncation, relevant for gauge/gravity duality, which have the form of dS4 foliations over a fifth (radial direction. We investigate time-dependent deformations of those solutions in the search for gravitational duals of models of glueball inflation. A particular starting ansatz enables us to find a class of analytical solutions, corresponding to an ultra-slow roll inflationary regime. This regime may play a role in understanding the low l anomaly in the power spectrum of the CMB.
A gravity dual of ultra-slow roll inflation
Anguelova, Lilia
2016-10-01
We study time-dependent deformations of a certain class of backgrounds in type IIB supergravity. These backgrounds are solutions of a five-dimensional consistent truncation, relevant for gauge/gravity duality, which have the form of dS4 foliations over a fifth (radial) direction. We investigate time-dependent deformations of those solutions in the search for gravitational duals of models of glueball inflation. A particular starting ansatz enables us to find a class of analytical solutions, corresponding to an ultra-slow roll inflationary regime. This regime may play a role in understanding the low l anomaly in the power spectrum of the CMB.
Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; Strassler, Matthew
2016-07-01
We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.
Craig, Nathaniel; Longhi, Pietro; Strassler, Matthew
2016-01-01
We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.
Observation of KsKs resonances in deep inelastic scattering at HERA
Abe, T; Adamczyk, L; Adamus, M; Adler, V; Aghuzumtsyan, G; Antonioli, P; Antonov, A; Arneodo, M; Bailey, D S; Bamberger, A; Barakbaev, A N; Barbagli, G; Barbi, M; Bari, G; Barreiro, F; Bartsch, D; Basile, M; Bauerdick, L A T; Behrens, U; Bell, M; Bellagamba, L; Benen, A; Bertolin, A; Bhadra, S; Bloch, I; Bodmann, B; Bold, T; Boos, E G; Borras, K; Boscherini, D; Brock, I; Brook, N H; Brugnera, R; Brümmer, N; Bruni, A; Bruni, G; Bussey, P J; Butterworth, J M; Bylsma, B; Caldwell, A; Capua, M; Cara Romeo, G; Carli, T; Carlin, R; Catterall, C D; Chekanov, S; Chiochia, V; Chwastowski, J; Ciborowski, J; Ciesielski, R; Cifarelli, Luisa; Cindolo, F; Cloth, P; Cole, J E; Collins-Tooth, C; Contin, A; Cooper-Sarkar, A M; Coppola, N; Cormack, C; Corradi, M; Corriveau, F; Cottrell, A; D'Agostini, Giulio; Dal Corso, F; Danilov, P; Dannheim, D; De Pasquale, S; Dementiev, R K; Derrick, M; Deshpande, Abhay A; Devenish, R C E; Dhawan, S; Dolgoshein, B A; Doyle, A T; Drews, G; Durkin, L S; Dusini, S; Eisenberg, Y; Ermolov, P F; Eskreys, Andrzej; Ferrando, J; Ferrero, M I; Figiel, J; Filges, D; Foster, B; Foudas, C; Fourletov, S; Fourletova, J; Fricke, U; Fusayasu, T; Gabareen, A; Gallo, E; Garfagnini, A; Geiser, A; Genta, C; Gialas, I; Giusti, P; Gladilin, L K; Gladkov, D; Glasman, C; Gliga, S; Goers, S; Golubkov, Yu A; Goncalo, R; González, O; Göttlicher, P; Grabowska-Bold, I; Grijpink, S; Grzelak, G; Gutsche, O; Gwenlan, C; Haas, T; Hain, W; Hall-Wilton, R; Hamatsu, R; Hamilton, J; Hanlon, S; Hart, J C; Hartmann, H; Hartner, G; Hartner, G F; Heaphy, E A; Heath, G P; Heath, H F; Helbich, M; Heusch, C A; Hilger, E; Hillert, S; Hirose, T; Hochman, D; Holm, U; Iacobucci, G; Iga, Y; Inuzuka, M; Irrgang, P; Jakob, H P; Jones, T W; Kagawa, S; Kahle, B; Kaji, H; Kananov, S; Kappes, A; Kataoka, Y; Yamazaki, M; Katkov, I I; Katz, U F; Kcira, D; Khein, L A; Kim, J Y; Kim, Y K; Kind, O; Kisielewska, D; Kitamura, S; Klimek, K; Koffeman, E; Kohno, T; Kooijman, P; Koop, T; Korzhav, I A; Kotanski, A; Kötz, U; Kowal, A M; Kowal, M; Kowalski, H; Kowalski, T; Krakauer, D; Kramberger, G; Kreisel, A; Krumnack, N; Kuze, M; Kuzmin, V A; Labarga, L; Labes, H; Lainesse, J; Lammers, S; Lee, J H; Lee, S W; Lelas, D; Levchenko, B B; Levman, G M; Levy, A; Li, L; Lightwood, M S; Lim, H; Lim, I T; Limentani, S; Ling, T Y; Liu, X; Löhr, B; Lohrmann, E; Loizides, J H; Long, K R; Longhin, A; Lukina, O Yu; Lupi, A; Luzniak, P; Maddox, E; Magill, S; Mankel, R; Margotti, A; Marini, G; Martin, J F; Mastroberardino, A; Matsuzawa, K; Mattingly, M C K; McCubbin, N A; Mellado, B; Melzer-Pellmann, I A; Menary, S R; Metlica, F; Meyer, U; Milite, M; Mirea, A; Monaco, V; Montanari, A; Moritz, M; Musgrave, B; Nagano, K; Nania, R; Nguyen, C N; Nigro, A; Ning, Y; Nishimura, T; Notz, D; Nowak, R J; Oh, B Y; Olkiewicz, K; Pac, M Y; Padhi, S; Paganis, S; Palmonari, F; Parenti, A; Park, I H; Patel, S; Paul, E; Pavel, N; Pawlak, J M; Pelfer, P G; Pellegrino, A; Pesci, A; Petrucci, M C; Piotrzkowski, K; Plucinsky, P P; Pokrovskiy, N S; Polini, A; Posocco, M; Proskuryakov, A S; Przybycien, M B; Rautenberg, J; Raval, A; Reeder, D D; Ren, Z; Renner, R; Repond, J; Riveline, U; Karshon, M; Robins, S; Rodrigues, E; Rosin, M; Rurua, L; Ruspa, M; Sacchi, R; Salehi, H; Sartorelli, G; Savin, A A; Saxon, D H; Schagen, S; Schioppa, M; Schlenstedt, S; Schmidke, W B; Schneekloth, U; Sciulli, F; Scott, J; Selonke, F; Shcheglova, L M; Skillicorn, I O; Slominski, W; Smith, W H; Soares, M; Solano, A; Son, D; Sosnovtsev, V V; Stairs, D G; Stanco, L; Standage, J; Stifutkin, A; Stoesslein, U; Stonjek, S; Stopa, P; Straub, P B; Suchkov, S; Susinno, G; Suszycki, L; Sutton, M R; Sztuk, J; Szuba, D; Szuba, J; Tandler, J; Tapper, A D; Tapper, R J; Tassi, E; Tawara, T; Terron, J; Tiecke, H G; Tokushuku, K; Tsurugai, T; Turcato, M; Tymieniecka, T; Ukleja, A; Ukleja, J; Vázquez, M; Velthuis, J J; Vlasov, N N; Voss, K C; Walczak, R; Walsh, R; Wang, M; Weber, A; Wessoleck, H; West, B J; Whitmore, J J; Wick, K; Wiggers, L; Wills, H H; Wing, M; Wolf, G; Yamada, S; Yamashita, T; Yoshida, R; Youngman, C; Zawiejski, L; Zeuner, W; Zhautykov, B O; Zichichi, A; Ziegler, A; Zotkin, S A; De Wolf, E; Del Peso, J
2004-01-01
Inclusive KsKs production in deep inelastic ep scattering at HERA has been studied with the ZEUS detector using an integrated luminosity of 120 pb-1. Two states are observed at masses of 1537 (+9)(-8) MeV and 1726 +- 7 MeV, as well as an enhancement around 1300 MeV. The state at 1537 MeV is consistent with the well established f2'(1525). The state at 1726 MeV may be the glueball candidate f0(1710).
The Crystal Barrel: Meson Spectroscopy at LEAR with a 4$\\pi$ Detector
2002-01-01
% PS197 \\\\ \\\\The Crystal Barrel is a 4$\\pi$ spectrometer designed to provide complete and precise information on practically every final state produced in $\\bar{p} p $ and $\\bar{p}d $ annihilations at low energy and to collect high statistics data samples. Selective triggers can be applied when necessary. \\\\ \\\\The physics goal is to identify all light mesons in the mass range from 0.14 to 2.3~GeV/c$^{2}$, to determine their quantum numbers and decay properties and to study the annihilation dynamics. The main interest is to find the glueball and hybrid degrees of freedom predicted in the framework of Quantum Chromodynamics. \\\\ \\\\\
1988 CELLO, JADE, and PLUTO contributions to ''exotic'' meson spectroscopy
Feindt, M.
1989-04-25
This article reviews selected recent results on resonance formation in ..gamma gamma.. reactions obtained with the CELLO, JADE, and PLUTO spectrometers at the /ital e//sup +//ital e/minus// storage ring PETRA. New stringent limits on the ..gamma gamma.. coupling of glueball candidates as well as new results on tensor and scalar mesons are presented. The recent observation of ..pi../sub 2/(1680) formation is confirmed by the CELLO group. Finally the two spin 1 states observed in ..gamma gamma../sup */ interactions, in particular the parity of the /ital X//sub 1/(1420) and the model dependence of present analyses are discussed.
Cooper, S.
1985-10-01
Heavy quark systems and glueball candidates, the particles which are relevant to testing QCD, are discussed. The review begins with the heaviest spectroscopically observed quarks, the b anti-b bound states, including the chi state masses, spins, and hadronic widths and the non-relativistic potential models. Also, P states of c anti-c are mentioned. Other heavy states are also discussed in which heavy quarks combine with lighter ones. The gluonium candidates iota(1460), theta(1700), and g/sub T/(2200) are then covered. The very lightest mesons, pi-neutral and eta, are discussed. 133 refs., 24 figs., 16 tabs. (LEW)
Hadron Spectroscopy in Double Pomeron Exchange Experiments
Albrow, Michael [Fermilab
2016-11-15
Central exclusive production in hadron-hadron collisions at high energies, for example p + p -> p + X + p, where the "+" represents a large rapidity gap, is a valuable process for spectroscopy of mesonic states X. At collider energies the gaps can be large enough to be dominated by pomeron exchange, and then the quantum numbers of the state X are restricted. Isoscalar JPC = 0++ and 2++ mesons are selected, and our understanding of these spectra is incomplete. In particular, soft pomeron exchanges favor gluon-dominated states such as glueballs, which are expected in QCD but not yet well established. I will review some published data.
Dimensional structural constants from chiral and conformal bosonization of QCD
Andrianov, A A; Ebert, D; Mann, T F; Mann, Th. Feld
1997-01-01
We derive the dimensional non-perturbative part of the QCD effective ac= tion for scalar and pseudoscalar meson fields by means of chiral and conformal bosonization. The related structural coupling constants L_5 and L_8 of th= e chiral lagrangian are estimated using general relations which are valid i= n a variety of chiral bosonization models without explicit reference to model parameters. The asymptotics for large scalar fields in QCD is elaborated,= and model-independent constraints on dimensional coupling constants of the effective meson lagrangian are evaluated. We determine also the interacti= on between scalar quarkonium and the gluon density and obtain the scalar glueball-quarkonium potential.
Search for gluonic excitations in light unconventional mesons
Paul Eugenio
2007-07-01
Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenologicalmodels for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as exotics, hybrids, multi-quarks, and glueballs. First discussion of the status of exotic meson searches is given followed by a discussion of plans at Jefferson Lab to double the energy of the machine to 12 GeV, which will allow us to access photoproduction of mesons in search for gluonic excited states.
Transport coefficients in Yang-Mills theory and QCD
Strodthoff, Nils; Christiansen, Nicolai; Haas, Michael [Institut fuer Theoretische Physik, Heidelberg (Germany); Pawlowski, Jan M. [Institut fuer Theoretische Physik, Heidelberg (Germany); ExtreMe Matter Institute EMMI, Darmstadt (Germany)
2015-07-01
We calculate the shear viscosity over entropy density ratio η/s in Yang-Mills theory from the Kubo formula using an exact diagrammatic representation in terms of full propagators and vertices using gluon spectral functions as external input. We provide an analytic fit formula for the temperature dependence of η/s over the whole temperature range from a glueball resonance gas at low temperatures, to a high-temperature regime consistent with perturbative results. Subsequently we provide a first estimate for η/s in QCD.
Variations on the Warped Deformed Conifold
Gubser, S S; Klebanov, I R; Gubser, Steven S.; Herzog, Christopher P.; Klebanov, Igor R.
2004-01-01
The warped deformed conifold background of type IIB theory is dual to the cascading $SU(M(p+1))\\times SU(Mp)$ gauge theory. We show that this background realizes the (super-)Goldstone mechanism where the U(1) baryon number symmetry is broken by expectation values of baryonic operators. The resulting massless pseudo-scalar and scalar glueballs are identified in the supergravity spectrum. A D-string is then dual to a global string in the gauge theory. Upon compactification, the Goldstone mechanism turns into the Higgs mechanism, and the global strings turn into ANO strings.
Dynamical corrections to the anomalous holographic softwall model: the pomeron and the odderon
Capossoli, Eduardo Folco; Boschi-Filho, Henrique
2016-01-01
In this work we use the holographic softwall AdS/QCD model with anomalous dimension contributions coming from two different QCD beta functions to calculate the masses of higher spin glueball states for both even and odd spins and its respective Regge trajectories, related to the pomeron and the odderon, respectively. We further investigate this model taking into account dynamical corrections due to a dilaton potential consistent with Einstein equations in 5 dimensions. The results found in this work for the Regge trajectories within the anomalous softwall model with dynamical corrections are consistent with those presented in the literature.
Predictions of High Energy Experimental Results
Comay E.
2010-10-01
Full Text Available Eight predictions of high energy experimental results are presented. The predictions contain the + charge radius and results of two kinds of experiments using energetic pionic beams. In addition, predictions of the failure to find the following objects are presented: glueballs, pentaquarks, Strange Quark Matter, magnetic monopoles searched by their direct interaction with charges and the Higgs boson. The first seven predictions rely on the Regular Charge-Monopole Theory and the last one relies on mathematical inconsistencies of the Higgs Lagrangian density.
The GlueX experiment: Search for gluonic excitations via photoproduction at Jefferson Lab
Eugenio, Paul [Florida State U.
2013-07-01
Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenological models for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as exotics, hybrids, multi-quarks, and glueballs. First discussion of the status of exotic meson searches is given followed by an overview of the progress at Jefferson Lab to double the energy of the machine to 12 GeV, which will allow us to access photoproduction of mesons in search for gluonic excited states.
Hagedorn spectrum and thermodynamics of SU(2) and SU(3) Yang-Mills theories
Caselle, Michele; Panero, Marco
2015-01-01
We present a high-precision lattice calculation of the equation of state in the confining phase of SU(2) Yang-Mills theory. We show that the results are described very well by a gas of massive, non-interacting glueballs, provided one assumes an exponentially growing Hagedorn spectrum. The latter can be derived within an effective bosonic closed-string model, leading to a parameter-free theoretical prediction, which is in perfect agreement with our lattice results. Furthermore, when applied to SU(3) Yang-Mills theory, this effective model accurately describes the lattice results reported by Bors\\'anyi et al. in JHEP 07 (2012) 056.
Overview of the status/results in the exotics sector
Shen, Chengping; Li, Changsheng
2016-11-01
Many exotic hadronic states beyond the conventional quark model (called char-moniumlike/bottomoniumlike states or XYZ particles) were found in the B-factories or energy scans of the cross sections of e+e- annhilation into conventional quarkonia and light hadrons. Their nature properties were proposed including glueballs, hybrids, multi-quark states, hadron molecules, etc. Dramatic progress was made in the study of the them after the running of the B-factories. In this report, I present the most recent results on the XYZ results from Belle experiment.
Towards the large N limit of pure Nu = 1 super Yang-Mills theory.
Maldacena, J; Nuñez, C
2001-01-22
We find the gravity solution corresponding to a large number of Neveu-Schwarz or D5-branes wrapped on a two sphere so that we have pure Nu = 1 super Yang-Mills in the IR. The supergravity solution is smooth, it shows confinement, and it breaks the U(1)(R) chiral symmetry in the appropriate way. When the gravity approximation is valid the masses of glueballs are comparable to the masses of Kaluza-Klein (KK) states on the 5-brane, but if we could quantize strings on this background it looks like we should be able to decouple the KK states.
An asymptotic solution of large-$N$ $QCD$
Bochicchio, Marco
2014-01-01
We find an asymptotic solution for two-, three- and multi-point correlators of local gauge-invariant operators, in a lower-spin sector of massless large-$N$ $QCD$, in terms of glueball and meson propagators, in such a way that the solution is asymptotic in the ultraviolet to renormalization-group improved perturbation theory, by means of a new purely field-theoretical technique that we call the asymptotically-free bootstrap, based on a recently-proved asymptotic structure theorem for two-point correlators. The asymptotically-free bootstrap provides as well asymptotic $S$-matrix amplitudes in terms of glueball and meson propagators. Remarkably, the asymptotic $S$-matrix depends only on the unknown particle spectrum, but not on the anomalous dimensions, as a consequence of the $LSZ$ reduction formulae. Very many physics consequences follow, both practically and theoretically. In fact, the asymptotic solution sets the strongest constraints on any actual solution of large-$N$ $QCD$, and in particular on any strin...
An asymptotic solution of large-$N$ $QCD$, and of large-$N$ $\\mathcal{N}=1$ $SUSY$ $QCD$
Bochicchio, Marco
2014-01-01
We find an asymptotic solution for two- and three-point correlators of local gauge-invariant operators, in a lower-spin sector of massless large-$N$ $QCD$ (and of massless large-$N$ $\\cal{N}$ $=1$ $SUSY$ $QCD$), in terms of glueball and meson propagators (and of their $SUSY$ partners), by means of a new purely field-theoretical technique that we call the asymptotically-free bootstrap. The asymptotically-free bootstrap exploits the lowest-order conformal invariance of connected correlators of gauge invariant composite operators in perturbation theory, the renormalization-group improvement, and a recently-proved asymptotic structure theorem for glueball and meson propagators (and for their $SUSY$ partners), that involves the unknown particle spectrum and the anomalous dimension of operators for fixed spin. In principle the asymptotically-free bootstrap extends to all the higher-spin two- and three-point correlators whose lowest-order conformal limit is non-vanishing in perturbation theory, and by means of the o...
Soft gluons are heavy and rowdy
Alkofer, R; Cotanch, S R; Fischer, C S; Llanes-Estrada, F J; Alkofer, Reinhard; Bicudo, Pedro; Cotanch, Stephen R.; Fischer, Christian S.; Llanes-Estrada, Felipe J.
2006-01-01
We study dynamical mass generation in pure Yang-Mills theory and report on a recently developed ansatz that exactly solves the tower of Dyson-Schwinger equations in Landau gauge at low Euclidean momentum, featuring enhanced gluon-gluon vertices, a finite ghost-gluon vertex in agreement with an old argument of Taylor, and an IR suppressed gluon propagator. This ansatz reinforces arguments in favor of the concept of a gluon mass gap at low momentum (although the minimum of the gluon's dispersion relation is not at zero momentum). As an application, we have computed the spectrum of oddballs, three-gluon glueballs with negative parity and C-parity. The three body problem is variationally solved employing the color density-density interaction of Coulomb gauge QCD with a static Cornell potential. Like their even glueball counterparts, oddballs fall on Regge trajectories with similar slope to the pomeron. However their intercept at t=0 is smaller than the omega Regge trajectory and therefore the odderon may only be ...
Remarks on Two-Dimensional Power Correction in Soft Wall Model
HUANG Tao; ZUO Fen
2008-01-01
We present a direct derivation of the two-point correlation function of the vector current in the soft wall model by using the AdS/CFT dictionary. The resulting correlator is exactly the same as the one previously obtained from dispersion relation with the same spectral function as in this model. The coeffcient C2 of the two-dimensional power correction is found to be C2 = -c/2 with c the slope of the Regge trajectory, rather than C2 = -c/3 derived from the strategy of the first quantized string theory. Taking the slope of the p trajectory c ≈ 0.9 CeV2 as input, we then obtain C2 ≈ -0.45 GeV2. The gluon condensate is found to be (αsG2) ≈ 0.064 GeV4, which is almost identical to the QCD sum rule estimation. By comparing these two equivalent derivation of the correlator of scalar glueball operator, we demonstrate that the two-dimensionai correction cannot be eliminated by including the non-leading solution in the bulk-to-boundary propagator, as carried out by Colangelo et al.[arXiv:0711.4747].In other words, the two-dimensional correction does exist in the scalar glueball case. Also it is manifest by using the dispersion relation that the minus sign of gluon condensate and violation of the low energy theorem are related to the subtraction scheme.
An asymptotic solution of large-N QCD
Bochicchio Marco
2014-01-01
Full Text Available We find an asymptotic solution for two-, three- and multi-point correlators of local gauge-invariant operators, in a lower-spin sector of massless large-N QCD, in terms of glueball and meson propagators, in such a way that the solution is asymptotic in the ultraviolet to renormalization-group improved perturbation theory, by means of a new purely field-theoretical technique that we call the asymptotically-free bootstrap, based on a recently-proved asymptotic structure theorem for two-point correlators. The asymptotically-free bootstrap provides as well asymptotic S-matrix amplitudes in terms of glueball and meson propagators. Remarkably, the asymptotic S-matrix depends only on the unknown particle spectrum, but not on the anomalous dimensions, as a consequence of the LS Z reduction formulae. Very many physics consequences follow, both practically and theoretically. In fact, the asymptotic solution sets the strongest constraints on any actual solution of large-N QCD, and in particular on any string solution.
Central Production of Two-Pseudoscalar Meson Systems at the COMPASS Experiment at CERN
Austregesilo, Alexander; Mallot, Gerhard
The question of the existence of glueballs is one of the unsolved problems in modern particle physics and can be regarded as a stringent test for quantum chromodynamics. Especially the supernumerous states in the light scalar meson spectrum are candidates for the observation of mixing effects between $q\\bar q$ mesons and pure gluonic bound states. On the other hand, the existence and the properties of many resonances in this sector are disputed. The COMPASS experiment was proposed to make significant contributions to this field. COMPASS is a fixed-target experiment at the CERN SPS which focused on light-quark hadron spectroscopy during the data taking periods in 2008 and 2009. A world-leading data set was collected with a $190\\,\\mathrm{GeV}/c$ hadron beam impinging on a liquid hydrogen target in order to study, inter alia, the central production of glueball candidates in the light meson sector. Especially the double-Pomeron exchange mechanism is well suited for the production of mesons without valenc...
On the consistency of the N=1 SYM spectra from wrapped five-branes
Ametller, L; Talavera, P; Ametller, Lluis; Pons, Josep Maria; Talavera, Pere
2003-01-01
We discuss the existence of glueball states for N=1 SYM within the Maldacena-Nunez model. We find that for this model the existence of an area law in the Wilson loop operator does not imply the existence of a discrete glueball spectrum. We suggest that implementing the model with an upper hard cut-off can amend the lack of spectrum. As a result the model can be only interpreted in the infra-red region. A direct comparison with the lattice data allows us to fix the scale up to where the model is sensible to describe low-energy observables. Nevertheless, taking for granted the lattice results, the resulting spectrum does not follow the general trends found in other supergravity backgrounds. We further discuss the decoupling of the non-singlet Kaluza-Klein states by analysing the associated supergravity equation of motion. The inclusion of non-commutative effects is also analysed and we find that leads to an enhancement on the value of the masses.
QCD in terms of gauge-invariant dynamical variables
Pavel, Hans-Peter
2013-01-01
For a complete description of the physical properties of low-energy QCD, it might be advantageous to first reformulate QCD in terms of gauge-invariant dynamical variables, before applying any approximation schemes. Using a canonical transformation of the dynamical variables, which Abelianises the non-Abelian Gauss-law constraints to be implemented, such a reformulation can be achieved for QCD. The exact implementation of the Gauss laws reduces the colored spin-1 gluons and spin-1/2 quarks to unconstrained colorless spin-0, spin-1, spin-2 and spin-3 glueball fields and colorless Rarita-Schwinger fields respectively. The obtained physical Hamiltonian can then be rewritten into a form, which separates the rotational from the scalar degrees of freedom, and admits a systematic strong-coupling expansion in powers of lambda=g^{-2/3}, equivalent to an expansion in the number of spatial derivatives. The leading-order term in this expansion corresponds to non-interacting hybrid-glueballs, whose low-lying masses can be ...
Central Production of Eta and Eta-prime via Double Pomeron Exchange in the Sakai-Sugimoto Model
Anderson, Neil; Harvey, Jeffrey A; Mann, Nelia
2014-01-01
We construct a string-inspired model for the central production of $\\eta$ and $\\eta'$ mesons in proton-proton collisions, via double Pomeron exchange. Using general symmetry considerations, we construct a low-energy differential cross section for double glueball exchange in terms of some undetermined coupling constants and form factors. We extend this model to the Regge regime, replacing the glueball propagators with Pomeron trajectories, and modifying the interaction term by a factor derived from the 5-string scattering amplitude in flat space. We then fix the couplings which remain undetermined, using the Sakai-Sugimoto framework to model low-energy QCD. Finally, we generate a simulation of the scattering process at $\\sqrt{s} = 29.1 GeV$, where double Pomeron exchange should play a role (secondary to double Reggeon exchange). We focus on the dependence of the scattering cross section on the angle between the scattered protons in the transverse plane. The results exhibit a definite deviation from the angular...
Unity of pomerons from gauge/string duality
Ballon-Bayona, Alfonso; Quevedo, Robert Carcassés; Costa, Miguel S.
2017-08-01
We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory of a 5-d string theory. It describes the exchange of higher spin fields in the graviton Regge trajectory that are dual to glueball states of twist two. For a specific holographic QCD model we describe Deep Inelastic Scattering in the Regge limit of low Bjorken x, finding good agreement with experimental data from HERA. The observed rise of the effective pomeron intercept, as the size of the probe decreases, is reproduced by considering the first four pomeron trajectories. In the case of soft probes, relevant to total cross sections, the leading hard pomeron trajectory is suppressed, such that in this kinematical region we reproduce an intercept of 1.09 compatible with the QCD soft pomeron data. In the spectral region of positive Maldelstam variable t the first two pomeron trajectories are consistent with current expectations for the glueball spectrum from lattice simulations.
An amplitude analysis of the pi0pi0 system produced in radiative J/psi decays
Bennett, Jake Vernon
Despite many years of study, a complete understanding of the interactions of quarks and gluons within hadronic states remains elusive. Quantum Chromodynamics (QCD) has long predicted the possibility of states in which gluonic excitations can contribute to the characteristics of the state (a hybrid) or even take the place of constituent quarks altogether (a glueball), yet no incontrovertible evidence yet exists. This is partially due to the nature of the low mass spectrum, in which broad, overlapping states make experimental methods challenging. Recent technological improvements and high statistics data sets now enable a rigorous study of regions in which experimentalists may perform fundamental tests of QCD. This dissertation presents one such study, focusing on the pi 0pi0 spectrum. Particular emphasis is placed on the scalar meson spectrum (JPC = 0++), wherein the lightest glueball state is expected. An amplitude analysis of the pi0pi0 system produced in radiative J/psi decays is presented. A mass independent analysis of the (1.3106 +/- 0.0072) x 10 9 J/psi decays collected by the BESIII detector at BEPCII in Beijing, China is repeated under different model assumptions and experimental conditions. Additionally, the branching ratio of radiative J/psi decays to pi0pi0 is measured to be (1.147+/-0.002+/-0.042) x 10-3, where the first error is statistical and the second is systematic. This is the first measurement of this reaction.
Buisseret, F., E-mail: fabien.buisseret@umons.ac.be [Service de Physique Nucleaire et Subnucleaire, Universite de Mons-UMONS, Academie universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons (Belgium); Haute Ecole Louvain en Hainaut (HELHa), Chaussee de Binche 159, B-7000 Mons (Belgium); Lacroix, G., E-mail: gwendolyn.lacroix@umons.ac.be [Service de Physique Nucleaire et Subnucleaire, Universite de Mons-UMONS, Academie universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons (Belgium)
2011-11-17
We discuss the dependence of pure Yang-Mills equation of state on the choice of gauge algebra. In the confined phase, we generalize to an arbitrary simple gauge algebra Meyer's proposal of modeling the Yang-Mills matter by an ideal glueball gas in which the high-lying glueball spectrum is approximated by a Hagedorn spectrum of closed-bosonic-string type. Such a formalism is undefined above the Hagedorn temperature, corresponding to the phase transition toward a deconfined state of matter in which gluons are the relevant degrees of freedom. Under the assumption that the renormalization scale of the running coupling is gauge-algebra independent, we discuss about how the behavior of thermodynamical quantities such as the trace anomaly should depend on the gauge algebra in both the confined and deconfined phase. The obtained results compare favorably with recent and accurate lattice data in the su(3) case and support the idea that the more the gauge algebra has generators, the more the phase transition is of first-order type.
Correlation functions in the Coulomb branch of N=4 SYM from AdS/CFT correspondence
Rashkov, R C
2000-01-01
In the present paper we study $S(N)\\to S(U(N/2)\\times U(N/2))$ symmetry breaking in ${\\mathcal N}=4$ SYM via AdS/CFT correspondence. We consider two stacks of N/2 parallel D3 branes separated by a distance $2\\vec d$. In this case there is mixing between the different l-wave dilatonic KK modes. We calculate certain two point correlation functions in the dual gauge theory. Due to mode mixing, the diagonal correlation functions have 1/N conformal-like correction as well as deformation terms. The off-diagonal correlators are also nonvanishing and their leading order is 1/N. We discuss briefly the spectrum of the glueball exitations.
Effects of non-perturbatively improved dynamical fermions in QCD at fixed lattice spacing
Allton, C R; Bowler, K C; Garden, J; Hart, A; Hepburn, D; Irving, A C; Joó, B; Kenway, R D; Maynard, C M; McNeile, C; Michael, C; Pickles, S M; Sexton, J C; Sharkey, K J; Sroczynski, Z; Talevi, M; Teper, M; Wittig, H
2002-01-01
We present results for the static inter-quark potential, lightest glueballs, light hadron spectrum and topological susceptibility using a non-perturbatively improved action on a $16^3\\times 32$ lattice at a set of values of the bare gauge coupling and bare dynamical quark mass chosen to keep the lattice size fixed in physical units ($\\sim 1.7$ fm). By comparing these measurements with a matched quenched ensemble, we study the effects due to two degenerate flavours of dynamical quarks. With the greater control over residual lattice spacing effects which these methods afford, we find some evidence of charge screening and some minor effects on the light hadron spectrum over the range of quark masses studied ($M_{PS}/M_{V}\\ge0.58$). More substantial differences between quenched and unquenched simulations are observed in measurements of topological quantities.
Search for large rapidity gap events in e+e- annihilation
Ellis, Jonathan Richard
1996-01-01
We Investigate the cross-section for the production of a low mass colour-singlet cluster in e^+ e^- annihilation with a large rapidity gap between the colour-singlet cluster and the other jets. It is argued that such events are the cross-channel analogue of large-rapidity events in deep-inelastic scattering, and therefore could in principle be used to investigate the analytic continuation of the BFKL pomeron to the positive t kinematic regime, where one would expect the trajectory to pass through glueball states. The cross section can be calculated in perturbative QCD, so that the infrared scale arising from non-perturbative effects which prevents an exponential fall-off with rapidity gap in the case of deep-inelastic scattering, is absent in e^+ e^- annihilation. Correspondingly, the cross-section for such events decreases rapidly with increasing rapidity gap.
Sannino, Francesco
2016-01-01
We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective...... at the electroweak scale. To illustrate the formalism we consider the possibility that the Higgs emerges as: the lightest glueball of a new composite theory; the large N scalar meson in models of dynamical electroweak symmetry breaking; the large N pseudodilaton useful also for models of near-conformal dynamics....... For each of these realisations we determine the leading N corrections to the electroweak precision parameters. The results nicely elucidate the underlying large N dynamics and can be used to confront first principle lattice results featuring composite scalars with a systematic effective approach....
2004-01-01
Extraction lines that carried the antiprotons from LEAR to the experiments. Beam-splitters and a multitude of beam-lines allowed several users to be supplied simultaneously. Particle physicists don't always need ever more powerful accelerators to study interesting physics. LEAR, the Low Energy Antiproton Ring, was designed to help explore the properties of antimatter, with the annihilation of protons and antiprotons becoming the main theme. LEAR was commissioned in 1983 and contributed to more than 30 experiments with great success. LEAR took part in the discovery of a 'glueball', a particle composed entirely of gluons, the carriers of the strong nuclear force. LEAR also observed that neutral kaons and antikaons decay at a slightly different rate, offering physicists another insight into the mystery about why matter prevails over antimatter in the Universe. Uniquely, LEAR combined both the electron and stochastic beam cooling techniques, used to control and refine the beams. It also pioneered a technique usin...
Pauli, H C; Pauli, Hans Christian; Bayer, Rolf
1996-01-01
The formalism for a non-abelian pure gauge theory in (2+1) dimensions has recently been derived within Discretized Light-Cone Quantization, restricting to the lowest {\\it transverse} momentum gluons. It is argued why this model can be a paradigm for full QCD. The physical vacuum becomes non-trivial even in light-cone quantization. The approach is brought here to tractable form by suppressing by hand both the dynamical gauge and the constraint zero mode, and by performing a Tamm-Dancoff type Fock-space truncation. Within that model the Hamiltonian is diagonalized numerically, yielding mass spectra and wavefunctions of the glue-ball states. We find that only color singlets have a stable and discrete bound state spectrum. The connection with confinement is discussed. The structure function of the gluons has a shape like [{x(1-x)}] ^{1\\over 3} . The existence of the continuum limit is verified by deriving a coupled set of integral equations.
Hamiltonian Study of Improved $U(1)_{2+1}$ Lattice Gauge Theory
Loan, M; Hamer, C; Loan, Mushtaq; Byrnes, Tim; Hamer, Chris
2003-01-01
Monte Carlo results are presented, in the Hamiltonian limit, for the string tension and antisymmetric mass gap for U(1) lattice gauge theory in (2+1) dimensions, using mean-field improved anisotropic Wilson action, are presented. Evidence of scaling in the string tension and antisymmetric mass gap is observed in the weak coupling regime of the theory. The results are compared to previous simulation data using the standard Wilson action and we find that a more accurate determination of the string tension and scalar glueball masses has been achieved. The scaling behaviour observed is in good agreement with the results from other numerical calculations. Finally comparisons are made with previous estimates obtained in the Hamiltonian limit by various other studies.
Mass gap in compact U(1) Model in (2+1) dimensions
Loan, M; Hamer, C; Loan, Mushtaq; Brunner, Michael; Hamer, Chris
2002-01-01
A numerical study of low-lying glueball masses of compact U(1) lattice gauge theory in (2+1) dimensions is performed using Standard Path integral Monte Carlo techniques. The masses are extracted, at fixed (low) temperature, from simulations on anisotropic lattices, with temporal lattice spacing much smaller than the spatial ones. Convincing evidence of the scaling behaviour in the antisymmetric mass gap is observed over the range $1.4<\\beta <2.25$. The observed behaviour is very consistent with asymptotic form predicted by G{\\" o}pfert and Mack. Extrapolations are made to the "Hamiltonian" limit, and the results are compared with previous estimates obtained by many other Hamiltonian studies.
Meson Spectroscopy at CLAS and CLAS12: the present and the future
Rafaella De Vita
2011-05-01
Mesons are the simplest quark bound system, being made by a quark and an anti-quark pair. Studying their structure and properties is a fundamental step to reach a deep understanding of QCD. For this purpose both a precise determination of the meson spectrum for conventional states and the search for states beyond the simple qq-bar configurations, as hybrids (qqg) or glueballs, are needed. Finding evidence for these unconventional states would help in understanding some of the open issues in hadronic physics, as how the quarks are confined within hadrons and what is the role of gluons. These topics are presently studied with the CLAS detector at Jefferson Lab and will be studied with the novel CLAS12 experiment after the 12 GeV upgrade of the facility. In my talk I will present the physics program that is presently in progress and the future perspectives.
Complete Phase Diagrams for a Holographic Superconductor/Insulator System
Horowitz, Gary T
2010-01-01
The gravitational dual of an insulator/superconductor transition driven by increasing the chemical potential has recently been constructed. However, the system was studied in a probe limit and only a part of the phase diagram was obtained. We include the backreaction and construct the complete phase diagram for this system. For fixed chemical potential there are typically two phase transitions as the temperature is lowered. Surprisingly, for a certain range of parameters, the system first becomes a superconductor and then becomes an insulator as the temperature approaches zero. As a byproduct of our analysis, we also construct the gravitational dual of a Bose-Einstein condensate of glueballs in a confining gauge theory.
The PANDA experiment: physics goals and experimental setup
Boca Gianluigi
2014-05-01
Full Text Available PANDA (antiProton ANnihilation at DArmstadt is an experiment that will run at the GSI laboratory, Darmstadt, Germany, in 2019. A high intensity antiproton beam with momentum up to 15 GeV/c will collide on a fixed proton target (pellet target or jet target. A wide range of physics topics will be investigated: char- monium states and open charm states above the DD¯$D\\overline D $ threshold; exotic states like glueballs, oddballs, hybrids, multiquarks, molecules; the spectroscopy of the excited states of strange and charm baryons; non-perturbative QCD dynamics in the pp¯$p\\overline p $ production cross section of charm and strange baryons and their spin correlations; the behaviour of hadrons in nuclear matter; hypernuclear physics; electromagnetic proton form factors in the timelike region; the CP violation in the charm sector, rare and forbidden decays of charm baryons and mesons.
Excluded-volume effects for a hadron gas in Yang-Mills theory
Alba, Paolo; Nada, Alessandro; Panero, Marco; Stöcker, Horst
2016-01-01
When the multiplicities of particles produced in heavy-ion collisions are fitted to the hadron-resonance-gas model, excluded-volume effects play a significant role. In this work, we study the impact of such effects onto the equation of state of pure Yang-Mills theory at low temperatures, comparing the predictions of the statistical model with lattice results. In particular, we present a detailed analysis of the SU(2) and SU(3) Yang-Mills theories: we find that, for both of them, the best fits to the equilibrium thermodynamic quantities are obtained when one assumes that the volume of different glueball states is inversely proportional to their mass. The implications of these findings for QCD are discussed.
Hagedorn spectrum and thermodynamics of SU(2) and SU(3) Yang-Mills theories
Caselle, Michele; Nada, Alessandro; Panero, Marco [Department of Physics, University of Turin & INFN,Via Pietro Giuria 1, I-10125 Turin (Italy)
2015-07-27
We present a high-precision lattice calculation of the equation of state in the confining phase of SU(2) Yang-Mills theory. We show that the results are described very well by a gas of massive, non-interacting glueballs, provided one assumes an exponentially growing Hagedorn spectrum. The latter can be derived within an effective bosonic closed-string model, leading to a parameter-free theoretical prediction, which is in perfect agreement with our lattice results. Furthermore, when applied to SU(3) Yang-Mills theory, this effective model accurately describes the lattice results reported by Borsányi et al. in http://dx.doi.org/10.1007/JHEP07(2012)056.
Towards the spectrum of low-lying particles in supersymmetric Yang-Mills theory
Bergner, Georg; Münster, Gernot; Özugurel, Umut D; Sandbrink, Dirk
2013-01-01
We present the current results of our simulations of N=1 supersymmetric Yang-Mills theory on a lattice. The masses of the gluino-glue particle, the a-eta-prime, the a-f0 meson, and the scalar glueball are obtained at finer lattice spacing than before, and extrapolations towards vanishing gluino mass are made. The calculations employ different levels of stout smearing. The statistical accuracy as well as the control of finite size effects and lattice artefacts are better than in previous investigations. Taking the statistical and systematic uncertainties into account, the extrapolations towards vanishing gluino mass of the masses of the fermionic and bosonic states in our present calculations are consistent with the formation of degenerate supermultiplets.
Shepherd, M R
2008-01-01
The charmonium system provides an opportunity to explore a wide variety of topics in hadronic physics. Studies of the properties of and transitions among cc-bar states yield insight into relativistic and non-perturbative QCD effects. At the same time, studies of the decays of charmonium states are a window into gluon dynamics and the role of glueball mixing in the production of light quark states. A collection of preliminary results utilizing the full CLEO-c psi(2S) data sample is presented including two-body branching fractions of chi_cJ decays, a precision measurement of the h_c mass, and results on the hindered M1 transition: psi(2S) -> gamma eta_c.
Pomeron-Quark Coupling from Charge Conjugation Invariance
ZHOU Li-Juan; WU Qing; MA Wei-Xing; GU Yun-Ting
2006-01-01
Based on the charge conjugation invariance and the vacuum property of the Pomeron, we point out that the commonly used vector vertex of the Pomeron coupling to quark is incorrect since it contradicts with the Pomeron property. We also claim that the soft Pomeron could be a tensor glueball ξ(2230) with quantum numbers IG JPC = 0+ 2++ and total decay width Γtot ≌ 100 MeV, which lies on the soft Pomeron trajectory αp = 1.08 + 0.20t. Therefore, the coupling vertex of the soft Pomeron to quark should be tensorial which is invariant under the charge conjugation and can explain why the inadequate vector coupling, γμ, of the soft Pomeron to quark is successful in dealing with Pomeron physics.
Hadron Physics at the COMPASS Experiment
Krinner, Fabian
2015-01-01
Quantum Chromodynamics (QCD), the theory of strong interactions, in principle describes the interaction of quark and gluon fields. However, due to the self-coupling of the gluons, quarks and gluons are confined into hadrons and cannot exist as free particles. The quantitative understanding of this confinement phenomenon, which is responsible for about 98\\% of the mass of the visible universe, is one of the major open questions in particle physics. The measurement of the excitation spectrum of hadrons and of their properties gives valuable input to theory and phenomenology. In the Constituent Quark Model (CQM) two types of hadrons exist: mesons, made out of a quark and an antiquark, and baryons, which consist of three quarks. But more advanced QCD-inspired models and Lattice QCD calculations predict the existence of hadrons with exotic properties interpreted as excited glue (hybrids) or even pure gluonic bound states (glueballs). The COMPASS experiment at the CERN Super Proton Synchrotron has acquired large da...
Future Prospects for Hadron Physics at PANDA
Wiedner, Ulrich
2011-01-01
The PANDA experiment at the new FAIR facility will be the major hadron physics experiment at the end of this decade. It has an ambitious far-reaching physics program that spans the most fascinating topics that are emerging in contemporary hadron physics. The universality of the antiproton annihilation process, with either protons or nuclei as targets, allows physicists to address questions like the structure of glueballs and hybrids; to clarify the nature of the X, Y and Z states; to investigate electromagnetic channels in order to measure form factors of the nucleon; and to provide theory with input with respect to non-perturbative aspects of QCD. The possibility to use different nuclear targets opens the window for charm physics with nuclei or for color transparency studies, as well as for an intensive hypernuclear physics program. Previous experimental experience has clearly demonstrated that the key to success lies in high levels of precision complemented with sophisticated analysis methods, only possible...
A 1+1 field theory spectrum from M theory
Rodríguez, M J; Rodriguez, Maria Jose; Talavera, Pere
2005-01-01
The spectrum of a 1+1 dimensional field theory with dynamical quarks is constructed. We focus in testing the possible brane embeddings that can support fundamental matter. The requirement on the wave function normalisation and the dependence on the quark mass of the quark condensate allow to discard most of the embeddings. We pay attention to some more general considerations comparing the behaviour of the non-compact theory at different dimensions. In particular we explored the possibility that the AdS/CFT duality ``formalism'' introduce a scale breaking parameter at (1+1)d allowing the existence of classical glueballs and its possible relation with point-like string configurations. The screening effects and the appearance of a possible phase transition is also discussed.
Renormalization group summation of Laplace QCD sum rules for scalar gluon currents
Farrukh Chishtie
2016-03-01
Full Text Available We employ renormalization group (RG summation techniques to obtain portions of Laplace QCD sum rules for scalar gluon currents beyond the order to which they have been explicitly calculated. The first two of these sum rules are considered in some detail, and it is shown that they have significantly less dependence on the renormalization scale parameter μ2 once the RG summation is used to extend the perturbative results. Using the sum rules, we then compute the bound on the scalar glueball mass and demonstrate that the 3 and 4-Loop perturbative results form lower and upper bounds to their RG summed counterparts. We further demonstrate improved convergence of the RG summed expressions with respect to perturbative results.
Ψ(2 S) Decay to J/Ψ(1 S) + 2 π or J/Ψ(1 S) + σ + 2 π
Kisslinger, Leonard S.; Li-juan, Zhou; Wei-xing, Ma; Shen, Pengnian
2017-03-01
We estimate the decay rate of the Ψ(2 S) to J/Ψ(1 S) + 2 π and J/Ψ(1 S) + σ + 2 π. This is based on the mixed hybrid theory that was developed for the Ψ(2 S) and was used to estimate the ratio {Ψ }(2S)→ J/{Ψ }(1S) + σ to {Ψ }(2S) → J/{Ψ }(1S) + 2 π in 2011. A main motivation of the present work is to predict the possible experimental detection of the decay of Ψ(2 S) to J/Ψ(1 S) + σ+2 π, or possibly to J/Ψ(1 S)+2 π+glueball.
The Witten-Sakai-Sugimoto model: A brief review and some recent results
Rebhan Anton
2015-01-01
Full Text Available A brief review of the Witten-Sakai-Sugimoto model is given, which is a top-down holographic model of low-energy QCD with chiral quarks derived from type-IIA superstring theory. The main predictions of the model, in particular concerning meson spectra, the gluon condensate, the QCD string tension, the mass of the η′ and of baryons are discussed and compared quantitatively with available experimental and/or lattice results. Then some recent results of potential interest to the physics program at the future FAIR facility are presented: The spectrum of glueballs and their decay rates into pions, and the phase diagram of QCD at finite temperature, density, and magnetic field strength.
Filinov, V.S.; Fortov, V.E. [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13, bd. 2, 125412 Moscow (Russian Federation); Bonitz, M. [Institute for Theoretical Physics and Astrophysics, Christian Albrechts University Kiel, Leibnizstrasse 15, D-24098 Kiel (Germany); Ivanov, Y.B. [National Research Center ' ' Kurchatov Institute' ' , Kurchatov Sq. 1, 123182 Moscow, Russia, National Research Nuclear University ' ' MEPhI' ' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation); Ilgenfritz, E.M. [Joint Institute for Nuclear Reseach, Joliot-Curie str. 6, Dubna, 141980, Moscow Region (Russian Federation)
2015-02-01
Based on the constituent quasiparticle model of the quark-gluon plasma (QGP), color quantum path-integral Monte-Carlo (PIMC) calculations of the thermodynamic properties of the QGP are performed. We extend our previous zero chemical potential simulations to the QGP at finite baryon chemical potential. The results indicate that color PIMC can be applied not only above the QCD critical temperature T{sub c} but also below T{sub c}. Besides reproducing the lattice equation of state our approach yields also valuable additional insight into the internal structure of the QGP, via the pair distribution functions of the various quasiparticles. In particular, the pair distribution function of gluons reflects the existence of gluon-gluon bound states at low temperatures and μ = 175 MeV, i.e. glueballs, while meson-like bound states are not found. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Physics projects of COMPASS with hadron beams
Faessler, M A
1999-01-01
COMPASS, a new state-of-the-art spectrometer to be installed at the CERN Super Proton Synchrotron for experiments with muon and hadron beams, will be exposed to hadron beams with intensities up to 10/sup 8//sec and energies up to 280 GeV. The physics goals are to study the rare production of charmed hadrons, including doubly charmed baryons, in inelastic interactions, with particular interest in their semileptonic decays; to search for glueballs and hybrids in central and diffractive production. Predictions of chiral perturbation theory will be tested in Primakoff reactions. The spectrometer shall be equipped with excellent particle identification and tracking, with calorimetry, dedicated triggers and fast read-out. A significant improvement of light hadron spectroscopy - compared to previous measurements -can be achieved already in the initial phase of the experiment. (4 refs).
(-p)p and pp Elastic Scattering at High Energies
无
2007-01-01
Based on the eikonalized Glauber representation of hadron-hadron scattering, we study the diffractive processes of -pp and pp elastic scattering at high energies. From our theoretical calculations and fits to the corresponding experimental data at high energies and all available momentum transfer, we find that the Pomeron exchange contributions play a significant role in description of differential cross section dσ/dt in the whole experimental domain. The Pomeron exchange contributions are related to multi-gluon exchanges in QCD, which are color singlet bound state of Reggeized gluons, such as tensor glueball and Odderon. Accordingly, we may claim that the -pp and pp diffractive processes at high energies s and moderate momentum transfer t would be a good tool to verify the existence of the color singlet multigluon bound states and to test QCD since QCD theory does predict the existence of these states. Therefore, we believe that the experimental measurement should be done for these diffractive processes.
Towards the spectrum of low-lying particles in supersymmetric Yang-Mills theory
Bergner, G. [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Montvay, I. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Muenster, G.; Oezugurel, U.D.; Sandbrink, D. [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1
2013-04-15
We present the current results of our simulations of N=1 supersymmetric Yang-Mills theory on a lattice. The masses of the gluino-glue particle, the a-{eta}', the a-f{sub 0} meson, and the scalar glueball are obtained at finer lattice spacing than before, and extrapolations towards vanishing gluino mass are made. The calculations employ different levels of stout smearing. The statistical accuracy as well as the control of finite size effects and lattice artefacts are better than in previous investigations. Taking the statistical and systematic uncertainties into account, the extrapolations towards vanishing gluino mass of the masses of the fermionic and bosonic states in our present calculations are consistent with the formation of degenerate supermultiplets.
Castro, Antonio Soares de
1990-05-01
A potential which incorporates the concepts of confinement and asymptotic freedom, previously utilized in the description of the spectroscopy of mesons and baryons, is extended to the gluon sector. The mass spectroscopy of glueballs and hybrids is analyzed considering only pairwise potentials and massive constituent gluons. The mass spectrum of the color octet two-gluon system is adopted as a suitable description of the intermediate states of hadronic transitions, within the framework of the multipole expansion for quantum chromodynamics. The spin-dependent effects in the gluonium spectrum, associated with the Coulombian potential, are calculated through the inverted first Born approximation for the gluon-gluon scattering. (author). 102 refs, 1 fig, 13 tabs.
Multiscale confining dynamics from holographic RG flows
Elander, Daniel [Department of Physics, Purdue University,525 Northwestern Avenue, West Lafayette, IN 47907-2036 (United States); Department of Theoretical Physics, Tata Institute of Fundamental Research,Homi Bhabha Road, Mumbai 400 005 (India); Faedo, Anton F. [Department of Physics, College of Science, Swansea University,Singleton Park, Swansea, Wales (United Kingdom); Departament de Física Fonamental & Institut de Ciències del Cosmos, Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain); Hoyos, Carlos [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University,Ramat-Aviv 69978 (Israel); Mateos, David [Departament de Física Fonamental & Institut de Ciències del Cosmos, Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA),Passeig Lluís Companys 23, E-08010, Barcelona (Spain); Piai, Maurizio [Department of Physics, College of Science, Swansea University,Singleton Park, Swansea, Wales (United Kingdom)
2014-05-05
We consider renormalization group flows between conformal field theories in five (six) dimensions with a string (M-theory) dual. By compactifying on a circle (torus) with appropriate boundary conditions, we obtain continuous families of confining four-dimensional theories parametrized by the ratio Λ{sub flow}/Λ{sub QCD}, with Λ{sub flow} the scale at which the flow between fixed points takes place and Λ{sub QCD} the confinement scale. We construct the dual geometries explicitly and compute the spectrum of scalar bound states (glueballs). We find a ‘universal’ subset of states common to all the models. We comment on the modifications of these models, and the corresponding fine-tuning, required for a parametrically light ‘dilaton’ state to be present. We also comment on some aspects of these theories as probed by extended objects such as strings and branes.
Multiscale confining dynamics from holographic RG flows
Elander, Daniel; Hoyos, Carlos; Mateos, David; Piai, Maurizio
2013-01-01
We consider renormalization group flows between conformal field theories in five (six) dimensions with a string (M-theory) dual. By compactifying on a circle (torus) with appropriate boundary conditions, we obtain continuous families of confining four-dimensional theories parametrized by the ratio $\\Lambda_{\\rm {\\tiny flow}}/\\Lambda_{\\rm \\tiny{QCD}}$, with $\\Lambda_{\\rm \\tiny{flow}}$ the scale at which the flow between fixed points takes place and $\\Lambda_{\\rm \\tiny{QCD}}$ the confinement scale. We construct the dual geometries explicitly and compute the spectrum of scalar bound states (glueballs). We find a `universal' subset of states common to all the models. We comment on the modifications of these models, and the corresponding fine-tuning, required for a parametrically light `dilaton' state to be present. We also comment on some aspects of these theories as probed by extended objects such as strings and branes.
Soft Pomeron in Holographic QCD
Ballon-Bayona, Alfonso; Costa, Miguel S; Djurić, Marko
2016-01-01
We study the graviton Regge trajectory in Holographic QCD as a model for high energy scattering processes dominated by soft pomeron exchange. This is done by considering spin J fields from the closed string sector that are dual to glueball states of even spin and parity. In particular, we construct a model that governs the analytic continuation of the spin J field equation to the region of real J < 2, which includes the scattering domain of negative Maldelstam variable t. The model leads to approximately linear Regge trajectories and is compatible with the measured values of 1.08 for the intercept and 0.25 GeV$^{-2}$ for the slope of the soft pomeron. The intercept of the secondary pomeron trajectory is in the same region of the subleading trajectories, made of mesons, proposed by Donnachie and Landshoff, and should therefore be taken into account.
Aspects of meson spectroscopy with N N annihilation
Dover, C.B.
1990-04-01
We focus on the potentialities of nucleon-antinucleon ({bar N}N) annihilation as a means of producing new mesonic states. The case for the existence of quasinuclear {bar N}N bound states is discussed in detail. Strong evidence for a 2{sup ++}(0{sup +}) state of this type has been obtained at LEAR in annihilation from the p-wave (L = 1) {bar N}N system, in support of earlier sightings of this object in L = 0 annihilation at Brookhaven. In the next generation of LEAR experiments, the emphasis shifts to the search for mesons containing dynamical excitations of the gluonic field, namely glueballs and hybrids (Q{bar Q}g). We discuss some features of the masses, decay branching ratios and production mechanisms for these states, and suggest particular {bar N}N annihilation channels which are optimal for their discovery. 59 refs., 15 figs.
Barberis, D; Binon, Freddy G; Blick, A M; Close, Francis Edwin; Danielsen, K M; Dolgopolov, A V; Donskov, S V; Earl, B C; Evans, D; French, Bernard R; Hino, T; Inaba, S; Inyakin, A V; Ishida, T; Jacholkowski, A; Jacobsen, T; Jones, G T; Khaustov, G V; Kinashi, T; Kinson, J B; Kirk, A; Klempt, W; Kolosov, V N; Kondashov, A A; Lednev, A A; Lenti, V; Maljukov, S; Martinengo, P; Minashvili, I A; Nakagawa, T; Norman, K L; Peigneux, J P; Polovnikov, S A; Polyakov, V A; Romanovsky, V I; Rotscheidt, Herbert; Rumyantsev, V; Rusakovitch, N A; Samoylenko, V D; Semenov, A A; Sené, M; Sené, R; Shagin, P M; Shimizu, H M; Singovsky, A V; Sobol, A E; Soloviev, A S; Stassinaki, M; Stroot, Jean-Pierre; Sugonyaev, V P; Takamatsu, K; Tchlatchidze, G A; Tsuru, T; Venables, M; Villalobos Baillie, O; Votruba, M F; Yasu, Y
1998-01-01
A study of the reactions pp -> pfps(K+K-pi+pi-) and pp -> pfps(K+K-pi+pi-pi0) shows evidence for the K*K* and phi omega channels respectively. The K*K* mass spectrum shows a broad distribution with a maximum near threshold and an angular analysis shows that it is compatible with having JP = 2+. The behaviour of the cross-section as a function of centre of mass energy, and the four momentum transfer dependence, are compatible with what would be expected if the K*K* system was produced via double Pomeron exchange. The dPT behaviour of the phi omega channel is similar to what has been observed for all the undisputed qqbar states. In contrast, the dPT behaviour of the K*K* final state is similar to what has been observed for the phi phi final state and for previously observed glueball candidates.
Partial-Wave Analysis of Centrally Produced Two-Pseudoscalar Final States in pp Reactions at COMPASS
Austregesilo, A
2014-01-01
COMPASS is a fixed-target experiment at the CERN SPS which focused on light-quark hadron spectroscopy during the data taking periods in 2008 and 2009. A world-leading data set was collected with a 190GeV/c hadron beam impinging on a liquid hydrogen target in order to study, inter alia, the central exclusive production of glueball candidates in the light-meson sector. Especially the double-Pomeron exchange mechanism is well suited for the production of mesons without valence quark content. We select centrally produced systems with two pseudo-scalar mesons in the final state from the COMPASS data set recorded with an incoming proton. The decay of this system is decomposed in terms of partial waves, where particular attention is paid to the inherent mathematical ambiguities of the amplitude analysis. Furthermore, we show that simple parametrisations are able to describe the mass dependence of the fit results with sensible Breit-Wigner parameters.
Sannino, Francesco
2016-01-01
We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective...... at the electroweak scale. To illustrate the formalism we consider the possibility that the Higgs emerges as: the lightest glueball of a new composite theory; the large N scalar meson in models of dynamical electroweak symmetry breaking; the large N pseudodilaton useful also for models of near-conformal dynamics....... For each of these realisations we determine the leading N corrections to the electroweak precision parameters. The results nicely elucidate the underlying large N dynamics and can be used to confront first principle lattice results featuring composite scalars with a systematic effective approach....
Baryon-baryon bound states in a (2+1)-dimensional lattice QCD model
Faria da Veiga, Paulo A.; O'Carroll, Michael; Schor, Ricardo
2003-08-01
We consider bound states of two baryons (antibaryons) in lattice QCD in a Euclidean formulation. For simplicity, we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. For a small hopping parameter 0<κ≪1 and large glueball mass, we recently showed the existence of a (anti)baryonlike particle, with an asymptotic mass of the order of -3 ln κ and with an isolated dispersion curve, i.e., an upper gap property persisting up to near the meson-baryon threshold, which is of order -5 ln κ. Here, we show that there is no baryon-baryon (or antibaryon-antibaryon) bound state solution to the Bethe-Salpeter equation up to the two-baryon threshold, which is approximately -6 ln κ.
Scaling properties of SU(2) gauge theory with mixed fundamental-adjoint action
Rinaldi, Enrico; Lucini, Biagio; Patella, Agostino; Rago, Antonio
2012-01-01
We study the phase diagram of the SU(2) lattice gauge theory with fundamental-adjoint Wilson plaquette action. We confirm the presence of a first order bulk phase transition and we estimate the location of its end-point in the bare parameter space. If this point is second order, the theory is one of the simplest realizations of a lattice gauge theory admitting a continuum limit at finite bare couplings. All the relevant gauge observables are monitored in the vicinity of the fixed point with very good control over finite-size effects. The scaling properties of the low-lying glueball spectrum are studied while approaching the end-point in a controlled manner.
Future prospects in nuclear physics and the Japanese hadron facility
Metag, V. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)]|[Giessen Univ. (Germany). 2. Physikalisches Inst.
1998-05-01
The Japanese Hadron Facility (JHF) will provide new perspectives for a broad research program covering nuclear and particle physics, condensed matter physics, material sciences, and life sciences. In this talk, the future prospects of nuclear physics, as they are discussed within the community, are addressed. Recommendations worked out by the study groups, evaluating the long term perspectives of GSI, have hereby been used as a guideline. Nuclear physics is considered here in a broad sense as the physics of extended structured objects bound by the strong interaction, i.e. mesons, baryons, and nuclei. Preference is given to those subfields which would benefit most from the new experimental possibilities to the JHF. Consequently, the structure of exotic nuclei and hypernuclei, the properties of compressed hadronic matter and medium modifications of hadrons, spectroscopy of mesons, glueballs and baryons, and the parton structure of the nucleon are addressed and analyzed with regard to their future physics potential. (orig.)
Brandt, A.; Kuzucu, A.; Medinnis, M.; Ozdes, N.; Schlein, P.E.; Zeyrek, M.T.; Zweizig, J.G.; Cheze, J.B.; Zsembery, J.; 10.1007/s10052-002-1031-x
2002-01-01
We report measurements of the inclusive reaction, p pbar -> p X pbar, in events where either or both the beam-like final-state baryons were detected in Roman-pot spectrometers and the central system was detected in the UA2 calorimeter. A Double-Pomeron-Exchange (DPE) analysis of these data and single diffractive data from the same experiment demonstrates that, for central masses of a few GeV, the extracted Pomeron-Pomeron total cross section, sigma_PomeromPromeron, exhibits an enhancement which exceeds factorization expectations by an order-of-magnitude. This may be a signature for glueball production. The enhancement is shown to be independent of uncertainties connected with possible non-universality of the Pomeron flux factor. Based on our analysis, we present DPE cross section predictions, for unit (1 mb) Pomeron-Pomeron total cross section, at the Tevatron, LHC and the 920 GeV fixed-target experiment, HERA-B.
A study of the $\\omega\\omega$ channel produced in central pp interactions at 450 GeV/c
Barberis, D; Close, Francis Edwin; Danielsen, K M; Donskov, S V; Earl, B C; Evans, D; French, Bernard R; Hino, T; Inaba, S; Jacholkowski, A; Jacobsen, T; Khaustov, G V; Kinson, J B; Kirk, A; Kondashov, A A; Lednev, A A; Lenti, V; Minashvili, I A; Peigneux, J P; Romanovsky, V I; Rusakovitch, N A; Semenov, A A; Shagin, P M; Shimizu, H; Singovsky, A V; Sobol, A E; Stassinaki, M; Stroot, Jean-Pierre; Takamatsu, K; Tsuru, T; Villalobos Baillie, O; Votruba, M F; Yasu, Y
2000-01-01
The reaction pp -> pf (omega omega) ps has been studied at 450 GeV/c and a spin analysis of the omega omega channel has been performed for the first time in central production. Evidence is found for the f2(1910) in the JPC = 2++ wave with spin projection JZ = 2. This is the only state observed in central production with spin projection JZ = 2. Its dPT and phi dependencies are similar to those observed for other glueball candidates. In addition, evidence is found for a state with JPC = 4++ consistent with the f4(2300). The f0(2000), previously observed in the rho rho final state, is confirmed.
Karshon, Uri
2010-01-01
Inclusive production of K0S K0S in ep collisions was studied with the ZEUS detector. Significant production of JPC=2++ tensor mesons and of the 0++ glueball candidate f0(1710) was seen. Masses and widths were compared with previous experiments. The H1 Collaboration saw a charm pentaquark candidate in the D*p spectrum at 3.1 GeV, which was not confirmed by a ZEUS higher statistics search. With the full HERA data, H1 did not see a signal in this region. Masses, widths and helicity parameters of excited charm and charm-strange mesons were measured by ZEUS. Rates of c-quarks hadronising into these mesons were determined and a search for a radially excited charm meson was performed.
International Meeting: Excited QCD 2014
Giacosa, Francesco; Malek, Magdalena; Marinkovic, Marina; Parganlija, Denis
2014-01-01
Excited QCD 2014 will take place on the beautiful Bjelasnica mountain located in the vicinity of the Bosnian capital Sarajevo. Bjelasnica was a venue of the XIV Winter Olympic Games and it is situated only 30 kilometers from Sarajevo International Airport. The workshop program will start on February 2 and finish on February 8, 2014, with scientific lectures taking place from February 3 to 7. Workshop participants will be accomodated in Hotel Marsal, only couple of minutes by foot from the Olympic ski slopes. ABOUT THE WORKSHOP This edition is the sixth in a series of workshops that were previously organised in Poland, Slovakia, France and Portugal. Following the succesful meeting in 2013, the Workshop is returning to Sarajevo Olympic mountains in 2014, exactly thirty years after the Games. The workshop covers diverse aspects of QCD: (i) QCD at low energies: excited hadrons, glueballs, multiquarks. (ii) QCD at high temperatures and large densities: heavy-ion collisions, jets, diffraction, hadronisation, quark-...
Universal aspects in the equation of state for Yang-Mills theories
Nada, Alessandro
2015-01-01
We present high-precision lattice calculations of the thermodynamics of Yang-Mills theories with different gauge groups. In the confining phase, we show that the equation of state is described remarkably well by a gas of massive, non-interacting glueballs, provided that an effective bosonic closed-string model is used to derive an exponentially growing Hagedorn spectrum for the heavy states. In particular, this model describes very accurately the results for the SU(3) theory reported by Bors\\'anyi et al. in JHEP 07 (2012) 056, as well as a novel set of lattice data for the SU(2) theory. In addition, we also also show that the equation of state in the deconfined phase exhibits a near perfect proportionality to the number of gluon degrees of freedom, including for the Yang-Mills theory based on the exceptional, center-less gauge group $G_2$.
AUTHOR|(CDS)2079223
2016-01-01
What is everything really made of? If we split matter down into smaller and infinitesimally smaller pieces, where do we arrive? At the Particle Zoo - the extraordinary subatomic world of antimatter, neutrinos, strange-flavoured quarks and yetis, gravitons, ghosts and glueballs, mindboggling eleven-dimensional strings and the elusive Higgs boson itself. Be guided around this strangest of zoos by Gavin Hesketh, experimental particle physicist at humanity's greatest experiment, the Large Hadron Collider. Concisely and with a rare clarity, he demystifies how we are uncovering the inner workings of the universe and heading towards the next scientific revolution. Why are atoms so small? How did the Higgs boson save the universe? And is there a theory of everything? The Particle Zoo answers these and many other profound questions, and explains the big ideas of Quantum Physics, String Theory, The Big Bang and Dark Matter...and, ultimately, what we know about the true, fundamental nature of reality.
Hadron Spectroscopy with COMPASS at CERN
Schönning, Karin
2012-01-01
The aim of the COMPASS hadron programme is to study the light-quark hadron spectrum, and in particular, to search for evidence of hybrids and glueballs. COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage spectrometer with high momentum resolution, large acceptance, particle identification and calorimetry. A short pilot run in 2004 resulted in the observation of a spin-exotic state with $J^{PC} =$ 1${−+}$ consistent with the debated /4\\pi_{1}$(1600). In addition, Coulomb production at low momentum transfer data provide a test of Chiral Perturbation Theory. During 2008 and 2009, a world leading data set was collected with hadron beam which is currently being analysed. The large statistics allows for a thorough decomposition of the data into partial waves. The COMPASS hadron data span over a broad range of channels and shed light on several different aspects of QCD.
Hadron Spectroscopy with COMPASS at CERN
Schönning, Karin
2012-01-01
The aim of the COMPASS hadron programme is to study the light-quark hadron spectrum, and in particular, to search for evidence of hybrids and glueballs. COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage spectrometer with high momentum resolution, large acceptance, particle identification and calorimetry. A short pilot run in 2004 resulted in the observation of a spin-exotic state with $J^{PC} = 1^{-+}$ consistent with the debated $\\pi1(1600)$. In addition, Coulomb production at low momentum transfer data provide a test of Chiral Perturbation Theory. During 2008 and 2009, a world leading data set was collected with hadron beam which is currently being analysed. The large statistics allows for a thorough decomposition of the data into partial waves. The COMPASS hadron data span over a broad range of channels and shed light on several different aspects of QCD.
The COMPASS Hadron Spectroscopy Programme
Austregesilo, A
2011-01-01
COMPASS is a fixed-target experiment at the CERN SPS for the investigation of the structure and the dynamics of hadrons. The experimental setup features a large acceptance and high momentum resolution spectrometer including particle identification and calorimetry and is therefore ideal to access a broad range of different final states. Following the promising observation of a spin-exotic resonance during an earlier pilot run, COMPASS focused on light-quark hadron spectroscopy during the years 2008 and 2009. A data set, world leading in terms of statistics and resolution, has been collected with a 190GeV/c hadron beam impinging on either liquid hydrogen or nuclear targets. Spin-exotic meson and glueball candidates formed in both diffractive dissociation and central production are presently studied. Since the beam composition includes protons, the excited baryon spectrum is also accessible. Furthermore, Primakoff reactions have the potential to determine radiative widths of the resonances and to probe chiral pe...
New results on the search for spin-exotic mesons with COMPASS
Nerling, Frank
2011-01-01
The COMPASS fixed-target experiment at the CERN SPS studies the structure and spectrum of hadrons. One important goal using hadron beams is the search for new states, in particlular spin-exotic mesons and glueballs. As a first input to the puzzle, COMPASS observed a significant $J^{PC}$ spin-exotic signal in the 2004 pilot run data (190\\,GeV/$c$ $\\pi^{-}$ beam, Pb target) in three charged pion final states consistent with the disputed $\\pi_1(1600)$. We started our hadron spectroscopy programme in 2008 by collecting very high statistics using a 190 GeV/$c$ negative pion beam scattered off a liquid hydrogen (proton) target. The current status and new results from the 2008 data on the search for the $\\pi_1(1600)$ resonance with exotic $J^{PC}=1^{-+}$ quantum numbers obtained from partial-wave analyses of the $\\rho\\pi$ and $\\eta'\\pi$ decay channels are presented.
De Sitter space in gauge/gravity duality
Lilia Anguelova
2015-10-01
Full Text Available We investigate gauge/gravity duality for gauge theories in de Sitter space. More precisely, we study a five-dimensional consistent truncation of type IIB supergravity, which encompasses a wide variety of gravity duals of strongly coupled gauge theories, including the Maldacena–Nunez solution and its walking deformations. We find several solutions of the 5d theory with dS4 spacetime and nontrivial profiles for (some of the scalars along the fifth (radial direction. In the process, we prove that one of the equations of motion becomes dependent on the others, for nontrivial warp factor. This dependence reduces the number of field equations and, thus, turns out to be crucial for the existence of solutions with (AdS4 spacetime. Finally, we comment on the implications of our dS4 solutions for building gravity duals of Glueball Inflation.
De Sitter space in gauge/gravity duality
Anguelova, Lilia; Suranyi, Peter; Wijewardhana, L. C. R.
2015-10-01
We investigate gauge/gravity duality for gauge theories in de Sitter space. More precisely, we study a five-dimensional consistent truncation of type IIB supergravity, which encompasses a wide variety of gravity duals of strongly coupled gauge theories, including the Maldacena-Nunez solution and its walking deformations. We find several solutions of the 5d theory with dS4 spacetime and nontrivial profiles for (some of) the scalars along the fifth (radial) direction. In the process, we prove that one of the equations of motion becomes dependent on the others, for nontrivial warp factor. This dependence reduces the number of field equations and, thus, turns out to be crucial for the existence of solutions with (A) dS 4 spacetime. Finally, we comment on the implications of our dS4 solutions for building gravity duals of Glueball Inflation.
De Sitter Space in Gauge/Gravity Duality
Anguelova, Lilia; Wijewardhana, L C Rohana
2014-01-01
We investigate gauge/gravity duality for gauge theories in de Sitter space. More precisely, we study a five-dimensional consistent truncation of type IIB supergravity, which encompasses a wide variety of gravity duals of strongly coupled gauge theories, including the Maldacena-Nunez solution and its walking deformations. We find several solutions of the 5d theory with dS_4 spacetime and nontrivial profiles for (some of) the scalars along the fifth (radial) direction. In the process, we prove that one of the equations of motion becomes dependent on the others, for nontrivial warp factor. This dependence reduces the number of field equations and, thus, turns out to be crucial for the existence of solutions with (A)dS_4 spacetime. Finally, we comment on the implications of our dS_4 solutions for building gravity duals of Glueball Inflation.
Unconstrained Hamiltonian formulation of low energy QCD
Pavel Hans-Peter
2014-04-01
Full Text Available Using a generalized polar decomposition of the gauge fields into gaugerotation and gauge-invariant parts, which Abelianises the Non-Abelian Gauss-law constraints to be implemented, a Hamiltonian formulation of QCD in terms of gauge invariant dynamical variables can be achieved. The exact implementation of the Gauss laws reduces the colored spin-1 gluons and spin-1/2 quarks to unconstrained colorless spin-0, spin-1, spin-2 and spin-3 glueball fields and colorless Rarita-Schwinger fields respectively. The obtained physical Hamiltonian naturally admits a systematic strongcoupling expansion in powers of λ = g−2/3, equivalent to an expansion in the number of spatial derivatives. The leading-order term corresponds to non-interacting hybridglueballs, whose low-lying spectrum can be calculated with high accuracy by solving the Schrödinger-equation of the Dirac-Yang-Mills quantum mechanics of spatially constant fields (at the moment only for the 2-color case. The discrete glueball excitation spectrum shows a universal string-like behaviour with practically all excitation energy going in to the increase of the strengths of merely two fields, the “constant Abelian fields” corresponding to the zero-energy valleys of the chromomagnetic potential. Inclusion of the fermionic degrees of freedom significantly lowers the spectrum and allows for the study of the sigma meson. Higher-order terms in λ lead to interactions between the hybridglueballs and can be taken into account systematically using perturbation theory in λ, allowing for the study of IR-renormalisation and Lorentz invarianz. The existence of the generalized polar decomposition used, the position of the zeros of the corresponding Jacobian (Gribov horizons, and the ranges of the physical variables can be investigated by solving a system of algebraic equations. Its exact solution for the case of one spatial dimension and first numerical solutions for two and three spatial dimensions indicate
A Perturbative Window into Non-Perturbative Physics
Dijkgraaf, R; Dijkgraaf, Robbert; Vafa, Cumrun
2002-01-01
We argue that for a large class of N=1 supersymmetric gauge theories the effective superpotential as a function of the glueball chiral superfield is exactly given by a summation of planar diagrams of the same gauge theory. This perturbative computation reduces to a matrix model whose action is the tree-level superpotential. For all models that can be embedded in string theory we give a proof of this result, and we sketch an argument how to derive this more generally directly in field theory. These results are obtained without assuming any conjectured dualities and can be used as a systematic method to compute instanton effects: the perturbative corrections up to n-th loop can be used to compute up to n-instanton corrections. These techniques allow us to see many non-perturbative effects, such as the Seiberg-Witten solutions of N=2 theories, the consequences of Montonen-Olive S-duality in N=1* and Seiberg-like dualities for N=1 theories from a completely perturbative planar point of view in the same gauge theo...
Hadron Spectroscopy with COMPASS – Newest Results
Nerling Frank
2012-12-01
Full Text Available The COMPASS experiment at the CERN SPS investigates the structure and spectrum of hadrons by scattering high energetic hadrons and polarised muons off various fixed targets. During the years 2002–2007, COMPASS focused on nucleon spin physics using 160 GeV/c polarised µ+ beams on polarised deuteron and proton targets, including measurements of the gluon contribution to the nucleon spin using longitudinal target polarisation as well as studies of transverse spin effects in the nucleon on a transversely polarised target. One major goal of the physics programme using hadron beams is the search for new states, in particular the search for JPC exotic states and glue-balls. COMPASS measures not only charged but also neutral final-state particles, allowing for investigation of new objects in different reactions and decay channels. In addition COMPASS can measure low-energy QCD constants like, e.g. the electromagnetic polarisability of the pion. Apart from a few days pilot run data taken in 2004 with a 190 GeV/c π− beam on a Pb target, showing a significant spin-exotic JPC = 1−+ resonance at around 1660 MeV/c2, COMPASS collected high statistics with negative and positive 190 GeV/c hadron beams on a proton (H2 and nuclear (Ni, Pb targets in 2008 and 2009. We give a selected overview of the newest results and discuss the status of various ongoing analyses.
Hadron Spectroscopy in COMPASS
Grube, Boris
2012-01-01
The COmmon Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron (SPS) aimed at studying the structure and spectrum of hadrons. In the naive Constituent Quark Model (CQM) mesons are bound states of quarks and antiquarks. QCD, however, predict the existence of hadrons beyond the CQM with exotic properties interpreted as excited glue (hybrids) or even pure gluonic bound states (glueballs). One main goal of COMPASS is to search for these states. Particularly interesting are so called spin-exotic mesons which have J^{PC} quantum numbers forbidden for ordinary q\\bar{q} states. Its large acceptance, high resolution, and high-rate capability make the COMPASS experiment an excellent device to study the spectrum of light-quark mesons in diffractive and central production reactions up to masses of about 2.5 GeV. COMPASS is able to measure final states with charged as well as neutral particles, so that resonances can be studied ...
Analytical approach to the D3-brane gravity dual for 3d Yang-Mills theory
Forkel, Hilmar
2015-01-01
The complexity of "top-down" string-dual candidates for strongly-coupled Yang-Mills theories and in particular for QCD almost always prohibits their exact analytical or even comprehensive numerical treatment. This impedes both a thorough quantitative analysis and the development of more realistic gravity duals. To mitigate these impediments, we devise an analytical approach to top-down duals on the basis of controlled, uniformly converging high-accuracy approximations for the normalizable string modes corresponding to gauge-theory states. We demonstrate the potential of this approach in Witten's dual for $3d$ Yang-Mills theory, i.e. in the near-horizon limit of non-extremal $D\\text{3}$-branes, compactified on $S^{1}$. We obtain accurate analytical approximations to the bulk modes which satisfy the boundary conditions exactly. On their basis, analytical results for masses, sizes, pole residues and correlation functions of glueball excitations are derived by spectral methods. These approximations can be systema...
Test of the OZI rule in vector meson production with the COMPASS experiment
Bernhard, Johannes
2012-01-01
The COMPASS experiment at CERN collected a large set of data with hadron beams ($p, \\pi, K$) and different targets (H$_{2}$, Pb, Ni, W) in the years 2008 and 2009. The main goal is the search for exotic bound states of quarks and gluons (glueballs, hybrids) and several preliminary results from the ongoing analysis have already emerged. The production of exotic states is known to be favoured in glue-rich environments, e.g. so-called OZI-forbidden processes. The Okubo-Zweig-Iizuka (OZI) rule states that processes with disconnected quark line diagrams are suppressed. As a consequence, states with an $s\\bar{s}$ component should be suppressed with respect to states containing mainly $u$ and $d$ quarks. The numerous reported violations of the OZI rule show that the underlying physics is more complicated. By studying the degree of OZI violation a lot can learned about the production mechanism and possibly also about the nucleon structure itself. The uniquely large COMPASS data sample allows for detailed studies wit...
Comments on "Diquarks, Strong Binding and a Large Hidden QCD Scale"
Shifman, M
2005-01-01
We present arguments regarding diquarks' possible role in low-energy hadron phenomenology that escaped theorists' attention so far. Good diquarks, i.e. the $0^{+}$ states of two quarks, are argued to have a two-component structure with one of the components peaking at distances several times shorter than a typical hadron size (a short-range core). This can play a role in solving two old puzzles of the 't Hooft 1/N expansion: strong quark mass dependence of the vacuum energy density and strong violations of the Okubo--Zweig--Iizuki (OZI) rule in the quark-antiquark $0^\\pm$ channels. In both cases empiric data defy 't Hooft's 1/N suppression. If good diquarks play a role at an intermediate energy scale they ruin 't Hoofts planarity because of their mixed-flavor composition. This new scale associated with the good diquarks may be related to a numerically large scale discovered in \\cite{NSVZ} in a number of phenomena mostly related to vacuum quantum numbers and $0^\\pm$ glueball channels. If SU(3)$_{\\rm color}$ of...
Olsen, Stephen Lars
2012-01-01
BESIII is a new state-of-the-art 4pi detector at the recently upgraded BEPCII two-ring e+e- collider at the Institute of High Energy Physics in Beijing. It has been in operation for three years, during which time it has collected the world's largest data samples of J/psi, psi' and psi(3770) decays. These data are being used to make a variety of interesting and unique studies of light-hadron spectroscopy, precision charmonium physics and high-statistics measurements of D-meson decays. Results that I describe in this report include studies of ao(980)-fo(980) mixing, an observation of a large isospin-violation in eta(1405)-->pi0fo(980) decays, some puzzles in J/psi and psi' decays to light hadrons, the observation of two glueball candidate states in radiative J/psi-->gamma pi+pi-eta' decays and some recent precision measurements of eta_c and h_c lineshapes.
Aubert, B; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Soni, N; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schröder, T; Steinke, M; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Panduro-Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Röthel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hrynóva, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H
2007-01-01
With a sample of 232x10^6 Upsilon(4S)->BBbar events collected with the BaBar detector, we study the decays of B mesons to ppbarh final states, where h=pi+,Ks,K*0 or K*+. We report evidence for the B->ppbarK*0 decay, with a branching fraction (1.5+/-0.5(stat)+/-0.4(syst))x10^-6, and for the B+->eta_cK*+ decay, with the branching fraction of Br(B+->eta_cK*+)xBr(eta_c->ppbar)=(1.57^{+0.56}_{-0.45}(stat)^{+0.46}_{-0.36}(syst))x10^-6, and provide improved measurements of the branching fractions of the other modes of this type. We also report the measurements of the charge asymmetry consistent with zero in the B+->ppbarpi+, B0->ppbarK*0 and B+->ppbarK*+ modes. No evidence is found for the pentaquark candidate Theta+ in the mass range 1.52 to 1.55 GeV/c^2, decaying into pKs, or the glueball candidate fJ(2220) in the mass range 2.2
COMPASS COmmon Muon and Proton Apparatus for Structure and Spectroscopy
Ciliberti, P; Wang, L; Ostrick, M; Platchkov, S; Lichtenstadt, J; Marianski, B M; Vertogradov, L; Yukaev, A; Meshcheriakov, G; Gushterski, R I; Orlov, I; Faessler, M; Doshita, N; Horikawa kondo, K; Menon, G; Ziembicki, M K; Beck, R; Dhara, L; Sarkar, S; Hsieh, C; Windmolders, R; Ramos, S E; Stolarski, M; Gerassimov, S; Kabuss, E; Du fresne von hohenesche, N; Marchand, C; Zhuravlev, N; Malyshev, V; Nagaytsev, A; Zemlyanichkina, E; Paul, S; Grabmueller, S; Michigami, T; Castelli, G; Sbrizzai, G; Matsuda, T; Kurjata, R P; Horikawa, N; Srnka, A; Dasgupta, S; Sawada, T; Barth, J; Denisov, O; Chiosso, M; Gnesi, I; Schiavon, P; Levorato, S; Baum, G; Reicherz, G A; Ter wolbeek, J A; Graf von harrach, D; Kurek, K; Tkachev, L; Ivanshin, I; Lavrentyev, V; Lishin, V; Liska, T; Konorov, I; Friedrich, J M; Austregesilo, A; Steffen, D; Iwata, T; Tessarotto, F; Joosten, R; Chang, W; Cotte, D G; Pretz, J J; Klein, F R; Hahne, D; Schmitt, L; Bradamante, F; Marques quintans, C; Franco, C; Burtin, E; Ferrero, A; Kuchinskiy, N; Guskov, A; Rogacheva, N; Konstantinov, V; Mikhaylov, Y; Kraemer, M C; Matsuda, H; Grosse-perdekamp, M; Schmieden, H; Bertini, R; Bordalo, P; Faria pereira lopes da silva, L M F; Tskhay, V; Meyer, W P; Fischer, H; Herrmann, F; D'hose, N; Augustyniak, W J; Alexeev, G; Kiselev, Y; Kouznetsov, O; Samartsev, A; Anfimov, N; Akhunzyanov, R; Khaustov, G; Khokhlov, I; Nikolaenko, V; Slunecka, M; Virius, M; Uhl, S; Peng, J; Riedl, C K; Szabelski, A; Da rocha azevedo, C D; Suzuki, H; Sinha, L; Mallot, G; Martin, A; Badelek, B M; Da silva nunes, A S; Nowak, W; Neyret, D; Sandacz, A; Efremov, A; Peshekhonov, D; Pontecorvo, G; Savin, I; Vlasov, N; Ryabchikov, D; Finger, M; Haas, F; Montuenga sfeir, P J; Birsa, R; Dalla torre, S; Crespo, M L; Vauth, A S; Balestra, F; Amoroso, A; Tessaro, S; Varanda quaresma, M M; Kotzinian, A; Buchele, M; Sirtl, S M; Kunne, F; Bedfer, Y; Seder, E E; Donskov, S; Poliakov, V; Finger, M; Grube, B; Marzec, J; Bisplinghoff, J; Das, S; Piragino, G; Tosello, F; Parsamyan, B; Bressan, A; Makke, N; Ishimoto, S; Menezes pires, C; Sznajder, P; Anosov, V; Gavrishchuk, O; Olshevskiy, A; Chirikov-zorin, I; Kravchuk, N; Antonov, A; Samoylenko, V; Kolosov, V; Novy, J; Mann, A B; Huber, S; Cicuttin, A; Zaremba, K; Hinterberger, F; Jahn, R J; Sulc, M; Teng, Y
2002-01-01
%NA58 %title\\\\ \\\\COMPASS is a new fixed target experiment at the SPS to study hadron spectroscopy with hadron beams (up to 300~GeV/c) and hadron structure with polarized muon beams (100-200~GeV/c).\\\\ \\\\The main physics objective of the muon beam program is the measurement of $\\Delta$G, the gluon polarization in a longitudinally polarized nucleon. More generally, it is planned to measure the flavour separated spin structure functions of the nucleons in polarized muon - polarized nucleon deep inelastic scattering, both with longitudinal and transverse target polarization modes. For these measurements a new 1.3~m long polarized target and a superconducting solenoid with 200~mrad acceptance will be used.\\\\ \\\\The hadronic program comprises a search for glueballs in the high mass region (above 2~GeV/c$^{2}$) in exclusive diffractive pp scattering, a study of leptonic and semileptonic decays of charmed hadrons with high statistics and precision, and Primakoff scattering with various probes. A detailed investigation ...
Light Scalar Mesons in Central Production at COMPASS
Austregesilo, A
2016-01-01
COMPASS is a fixed-target experiment at the CERN SPS that studies the spectrum of light-quark hadrons. In 2009, it collected a large dataset using a $190\\,$GeV$/c$ positive hadron beam impinging on a liquid-hydrogen target in order to measure the central exclusive production of light scalar mesons. One of the goals is the search for so-called glueballs, which are hypothetical meson-like objects without valence-quark content. We study the decay of neutral resonances by selecting centrally produced pion pairs from the COMPASS dataset. The angular distributions of the two pseudoscalar mesons are decomposed in terms of partial waves, where particular attention is paid to the inherent mathematical ambiguities. The large dataset allows us to perform a detailed analysis in bins of the two squared four-momentum transfers carried by the exchange particles in the reaction. Possible parameterisations of the mass dependence of the partial-wave amplitudes in terms of resonances are also discussed.
Baryon Transition in Holographic QCD
Li, Siwen
2015-01-01
We propose a mechanism of holographic baryon transition in the Sakai-Sugimoto (SS) model: baryons in this model can jump to different states under the mediated effect of gravitons (or glueballs by holography). We consider a time-dependent gravitational perturbation from M5-brane solution of D=11 supergravity and by employing the relations between 11D M-theory and IIA string theory, we get its 10 dimensional counterpart in the SS model. Such a perturbation is received by the D4-branes wrapped on the $S^{4}$ part of the 10D background, namely the baryon vertex. Technically, baryons in the SS model are described by BPST instanton ansatz and their dynamics can be analyzed using the quantum mechanical system in the instanton's moduli space. In this way, different baryonic states are marked by quantum numbers of moduli space quantum mechanics. By holographic spirit, the gravitational perturbation enters the Hamiltonian as a time-dependent perturbation and it is this time-dependent perturbative Hamiltonian produces ...
Configurational entropy of anti-de Sitter black holes
Braga, Nelson R. F.; da Rocha, Roldão
2017-04-01
Recent studies indicate that the configurational entropy is an useful tool to investigate the stability and (or) the relative dominance of states for diverse physical systems. Recent examples comprise the connection between the variation of this quantity and the relative fraction of light mesons and glueballs observed in hadronic processes. Here we develop a technique for defining a configurational entropy for an AdS-Schwarzschild black hole. The achieved result corroborates consistency with the Hawking-Page phase transition. Namely, the dominance of the black hole configurational entropy will be shown to increase with the temperature. In order to verify the consistency of the new procedure developed here, we also consider the case of black holes in flat space-time. For such a black hole, it is known that evaporation leads to instability. The configurational entropy obtained for the flat space case is thoroughly consistent with the physical expectation. In fact, we show that the smaller the black holes, the more unstable they are. So, the configurational entropy furnishes a reliable measure for stability of black holes.
Many-Body Coulomb Gauge Exotic and Charmed Hybrids
Llanes-Estrada, F J; Llanes-Estrada, Felipe J.; Cotanch, Stephen R.
2001-01-01
Utilizing a QCD Coulomb gauge Hamiltonian with linear confinement specified by lattice, we report a relativistic many-body calculation for the light exotic and charmed hybrid mesons. The Hamiltonian successfully describes both quark and gluon sectors, with vacuum and quasiparticle properties generated by a BCS transformation and more elaborate TDA and RPA diagonalizations for the meson ($q\\bar{q}$) and glueball ($gg$) masses. Hybrids entail a computationally intense relativistic three quasiparticle ($q\\bar{q}g$) calculation with the 9 dimensional Hamiltonian matrix elements evaluated variationally by Monte Carlo techniques. Our new TDA spectrum for the nonexotic $1^{--}$ charmed ($c\\bar{c}$ and $c\\bar{c}g$) system provides an explanation for the overpopulation of the observed $J/\\psi$ states. For the important $1^{-+}$ light exotic channel we obtain hybrid masses above 2 $GeV$, in broad agreement with lattice and flux tube models, indicating that the recently observed resonances at 1.4 and 1.6 $GeV$ are of di...
Dzhygadlo, R.; Schwarz, C.; Belias, A.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Schmidt, M.; Cowie, E.; Keri, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.
2016-05-01
The PANDA detector at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR) addresses fundamental questions of hadron physics. Experiments concerning charmonium spectroscopy, the search for hybrids and glueballs and the interaction of hidden and open charm particles with nucleons and nuclei will be performed with antiproton beams impinging on hydrogen or nuclear targets. Cooled beams allow the precision scan of resonances in formation experiments. The momentum range of the antiproton beam between 1.5 GeV/c and 15 GeV/c tests predictions by perturbation theory and will reveal deviations originating from strong QCD . An excellent hadronic particle identification will be accomplished by DIRC (Detection of Internally Reflected Cherenkov light) counters. The design for the barrel region is based on the successful BaBar DIRC with several key improvements, such as fast photon timing and a compact imaging region. DIRC designs based on different radiator geometries with several focusing options were studied in simulation. The performance of each design was characterized in terms of photon yield and single photon Cherenkov angle resolution. Selected design options were implemented in prototypes and tested with hadronic particle beams at GSI and CERN.
ComPWA: A common amplitude analysis framework for PANDA
Michel, M.; Feldbauer, F.; Götzen, K.; Jasinski, P.; Karavdina, A.; Peters, K.; Fritsch, M.
2014-06-01
A large part of the physics program of the PANDA experiment at FAIR deals with the search for new conventional and exotic hadronic states like e.g. hybrids and glueballs. For many analyses PANDA will need an amplitude analysis, e.g. a partial wave analysis (PWA), to identify possible candidates and for the classification of known states. Therefore, a new, agile and efficient amplitude analysis framework ComPWA is under development. It is modularized to provide easy extension with models and formalisms as well as fitting of multiple datasets, even from different experiments. Experience from existing PWA programs was used to fix the requirements of the framework and to prevent it from restrictions. It will provide the standard estimation and optimization routines like Minuit2 and the Geneva library and be open to insert additional ones. The challenges involve parallelization, fitting with a high number of free parameters, managing complex meta-fits and quality assurance / comparability of fits. To test and develop the software, it will be used with data from running experiments like BaBar or BESIII. These proceedings show the status of the framework implementation as well as first test results.
Design studies of the PWO End-cap Calorimeter for PANDA
Moeini, Hossein; Babai, Mohammad; Biegun, Alexandra; Bondarenko, Olga; Gotzen, Klaus; Kavatsyuk, Myroslav; Lindemulder, Michel; Lohner, Herbert; Melnychuk, Dima; Messchendorp, Johan; Smit, Henk; Spataro, Stefano; Veenstra, Rick
2013-01-01
The PANDA detection system at FAIR, Germany, is designed to study antiproton-proton annihilations, in order to investigate among others the realm of charm-meson states and glueballs, which has still much to reveal. The yet unknown properties of this field are to be unraveled through studying QCD phenomena in the non-perturbative regime. The multipurpose PANDA detector will be capable of tracking, calorimetry, and particle identification, and is foreseen to run at high luminosities providing average reaction rates up to 20 Million interactions/s. The envisaged physics program requires measurements of photons and charged particles with excellent energy, position, and time resolutions. The electromagnetic calorimeter (EMC) will serve as one of the basic components of the detector setup and comprises cooled Lead-Tungstate (PbWO4) crystals. This paper presents the mechanical design of the Forward End-cap calorimeter and analyses the response of this detector component in conjunction with the full EMC and the compl...
Bag model of hadrons, dual QCD thermodynamics and Quark-Gluon Plasma
Chandola, H C; Dehnen, H
2015-01-01
Using the grand canonical ensemble formulation of a multi-particle statistical system, the thermodynamical description of the dual QCD has been presented in terms of the bag model of hadrons and analyzed for the quark-gluon plasma phase of hadronic matter. The dual QCD bag construction has been shown to lead to the radial pressure on the bag surface in terms of the vector glueball masses of the magnetically condensed QCD vacuum. Constructing the grand canonical partition function to deal with the quark-gluon plasma phase of the non-strange hadrons, the energy density and the plasma pressure have been derived and used to understand the dynamics of the associated phase transition. The critical temperature for QGP-hadron phase transition has been derived and numerically estimated by using various thermodynamic considerations. A comparison of the values of the critical temperatures for QGP-hadron phase transition with those obtained for the deconfinement-phase transition, has been shown to lead to the relaxation ...
Hadron physics at the COMPASS experiment
Krinner, Fabian
2015-05-01
Quantum Chromodynamics (QCD), the theory of strong interactions, in principle describes the interaction of quark and gluon fields. However, due to the self-coupling of the gluons, quarks and gluons are confined into hadrons and cannot exist as free particles. The quantitative understanding of this confinement phenomenon, which is responsible for about 98% of the mass of the visible universe, is one of the major open questions in particle physics. The measurement of the excitation spectrum of hadrons and of their properties gives valuable input to theory and phenomenology. In the Constituent Quark Model (CQM) two types of hadrons exist: mesons, made out of a quark and an antiquark, and baryons, which consist of three quarks. But more advanced QCD-inspired models and Lattice QCD calculations predict the existence of hadrons with exotic properties interpreted as excited glue (hybrids) or even pure gluonic bound states (glueballs). The Compass experiment at the CERN Super Proton Synchrotron has acquired large data sets, which allow to study light-quark meson and baryon spectra in unprecedented detail. The presented overview of the first results from this data set focuses in particular on the light meson sector and presents a detailed analysis of three-pion final states. A new JPC = 1++ state, the a1(1420), is observed with a mass and width in the ranges m = 1412 - 1422MeV/c2 and Γ = 130 - 150MeV/c2.
Large mass hierarchies from strongly-coupled dynamics
Athenodorou, Andreas; Bergner, Georg; Elander, Daniel; Lin, C -J David; Lucini, Biagio; Piai, Maurizio
2016-01-01
Besides the Higgs particle discovered in 2012, with mass 125 GeV, recent LHC data show tentative signals for new resonances in diboson as well as diphoton searches at high center-of-mass energies (2 TeV and 750 GeV, respectively). If these signals are confirmed (or other new resonances are discovered at the TeV scale), the large hierarchies between masses of new bosons require a dynamical explanation. Motivated by these tentative signals of new physics, we investigate the theoretical possibility that large hierarchies in the masses of glueballs could arise dynamically in new strongly-coupled gauge theories extending the standard model of particle physics. We study lattice data on non-Abelian gauge theories in the (near-)conformal regime as well as a simple toy model in the context of gauge/gravity dualities. We focus our attention on the ratio $R$ between the mass of the lightest spin-2 and spin-0 resonances, that for technical reasons is a particularly convenient and clean observable to study. For models in ...
Yelnykov, O V
2005-01-01
This thesis addresses three topics: calculation of the invariant measure for the pure Yang-Mills configuration space in (3 + 1) dimensions, Hamiltonian analysis of the pure Chern-Simons theory on the noncommutative plane and noncommutative quantum mechanics in the presence of singular potentials. In Chapter 1 we consider a gauge-invariant Hamiltonian analysis for Yang-Mills theories in three spatial dimensions. The gauge potentials are parameterized in terms of a matrix variable which facilitates the elimination of the gauge degrees of freedom. We develop an approximate calculation of the volume element on the gauge-invariant configuration space. We also make a rough estimate of the ratio of 0++ glueball mass and the square root of string tension by comparison with (2 + 1)-dimensional Yang-Mills theory. In Chapter 2 the Hamiltonian analysis of the pure Chern- Simons theory on the noncommutative plane is performed. We use the techniques of geometric quantization to show that the classical reduced phase space o...
Crowe, K.M.
1992-01-01
The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p[bar p] annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report.
Crowe, K.M.
1992-12-01
The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p{bar p} annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report.
Quark-gluon plasma effects on hadrons in AdS/QCD
Bartz, Sean; Jacobson, Theodore
2016-09-01
The AdS/CFT correspondence has succeeded in describing qualitatively many features of non-perturbative QCD. An approach known as bottom-up AdS/QCD uses a dilaton field to break conformal symmetry, introducing confinement and describing well the features of hadronic spectra at zero temperature. Introducing a black hole into the AdS metric allows for the study of thermodynamic properties of QCD, mimicking the behavior of hadrons interacting with a hot, dense medium such as the quark-gluon plasma produced in heavy ion collisions. We present an improved AdS/QCD model for meson and glueball spectra at finite temperature and baryon chemical potential. The spectra match the experimental and lattice data qualitatively well at low temperature, but we also find some subtleties in connecting to the best zero-temperature models. We find a melting temperature for light mesons that is below the current estimates for the deconfinement temperature. Finally, we examine the melting and jet-quenching of heavy quarkonia, which more commonly act as probes of the QGP in heavy ion collisions.
Dual QCD thermodynamics and quark–gluon plasma
Chandola, H.C., E-mail: chandolaharish@gmail.com [Centre of Advanced Study, Department of Physics, Kumaun University, Nainital-263001 (India); Punetha, Garima [Centre of Advanced Study, Department of Physics, Kumaun University, Nainital-263001 (India); Dehnen, H. [Fachbereich Physik, Universität Konstanz, M 677, 78457 Konstanz (Germany)
2016-01-15
Using grand canonical ensemble formulation of a multi-particle statistical system, the thermodynamical description of dual QCD based on magnetic symmetry has been presented and analyzed for the quark–gluon plasma phase of hadronic matter. The dual QCD based bag construction has been shown to lead to the radial pressure on bag surface in terms of the vector glueball masses of magnetically condensed QCD vacuum. Constructing the grand canonical partition function, the energy density and plasma pressure have been derived and used to compute the critical temperatures for QGP–hadron phase transition along with its dynamics. A comparison of the values of critical temperatures for QGP–hadron phase transition with those obtained for the deconfinement-phase transition, has been shown to lead to either the relaxation of the system via a mixed phase of QGP and hot hadron gas or go through a crossover. The associated profiles of the normalized energy density and specific heat have been shown to lead to a large latent heat generation and indicate the onset of a first-order QGP phase transition which turns into a rapid crossover for the case of temperature dependent bag parameter. The squared speed of sound has been shown to act as a physical measure of large thermodynamical fluctuations near transition point. The possible implications of trace anomaly and conformal measure on QGP formation have also been discussed.
Data-driven model-independent searches for long-lived particles at the LHC
Coccaro, Andrea; Curtin, David; Lubatti, H. J.; Russell, Heather; Shelton, Jessie
2016-12-01
Neutral long-lived particles (LLPs) are highly motivated by many beyond the Standard Model scenarios, such as theories of supersymmetry, baryogenesis, and neutral naturalness, and present both tremendous discovery opportunities and experimental challenges for the LHC. A major bottleneck for current LLP searches is the prediction of Standard Model backgrounds, which are often impossible to simulate accurately. In this paper, we propose a general strategy for obtaining differential, data-driven background estimates in LLP searches, thereby notably extending the range of LLP masses and lifetimes that can be discovered at the LHC. We focus on LLPs decaying in the ATLAS muon system, where triggers providing both signal and control samples are available at LHC run 2. While many existing searches require two displaced decays, a detailed knowledge of backgrounds will allow for very inclusive searches that require just one detected LLP decay. As we demonstrate for the h →X X signal model of LLP pair production in exotic Higgs decays, this results in dramatic sensitivity improvements for proper lifetimes ≳10 m . In theories of neutral naturalness, this extends reach to glueball masses far below the b ¯b threshold. Our strategy readily generalizes to other signal models and other detector subsystems. This framework therefore lends itself to the development of a systematic, model-independent LLP search program, in analogy to the highly successful simplified-model framework of prompt searches.
Highlights from COMPASS in hadron spectroscopy
Krinner, Fabian
2015-01-01
Since Quantum Choromdynamics allows for gluon self-coupling, quarks and gluons cannot be observed as free particles, but only their bound states, the hadrons. This so-called confinement phenomenon is responsible for $98\\%$ of the mass in the visible universe. The measurement of the hadron excitation spectra therefore gives valuable input for theory and phenomenology to quantitatively understand this phenomenon. One simple model to describe hadrons is the Constituent Quark Model (CQM), which knows two types of hadrons: mesons, consisting of a quark and an antiquark, and baryons, which are made out of three quarks. More advanced models, which are inspired by QCD as well as calculations within Lattice QCD predict the existence of other types of hadrons, which may be e.g. described solely by gluonic excitations (glueballs) or mixed quark and gluon excitations (hybrids). In order to search for such states, the COMPASS experiment at the Super Proton Synchrotron at CERN has collected large data sets, which allow to ...
γ -ray Constraints on Decaying Dark Matter and Implications for IceCube
Cohen, Timothy; Murase, Kohta; Rodd, Nicholas L.; Safdi, Benjamin R.; Soreq, Yotam
2017-07-01
Utilizing the Fermi measurement of the γ -ray spectrum toward the Inner Galaxy, we derive some of the strongest constraints to date on the dark matter (DM) lifetime in the mass range from hundreds of MeV to above an EeV. Our profile-likelihood-based analysis relies on 413 weeks of Fermi Pass 8 data from 200 MeV to 2 TeV, along with up-to-date models for diffuse γ -ray emission within the Milky Way. We model Galactic and extragalactic DM decay and include contributions to the DM-induced γ -ray flux resulting from both primary emission and inverse-Compton scattering of primary electrons and positrons. For the extragalactic flux, we also calculate the spectrum associated with cascades of high-energy γ rays scattering off of the cosmic background radiation. We argue that a decaying DM interpretation for the 10 TeV-1 PeV neutrino flux observed by IceCube is disfavored by our constraints. Our results also challenge a decaying DM explanation of the AMS-02 positron flux. We interpret the results in terms of individual final states and in the context of simplified scenarios such as a hidden-sector glueball model.
A statistical approach to the QCD phase transition --A mystery in the critical temperature
Ishii, N; Ishii, Noriyoshi; Suganuma, Hideo
2002-01-01
We study the QCD phase transition based on the statistical treatment with the bag-model picture of hadrons, and derive a phenomenological relation among the low-lying hadron masses, the hadron sizes and the critical temperature of the QCD phase transition. We apply this phenomenological relation to both full QCD and quenched QCD, and compare these results with the corresponding lattice QCD results. Whereas such a statistical approach works well in full QCD, it results in an extremely large estimate of the critical temperature in quenched QCD, which indicates a serious problem in understanding of the QCD phase transition. This large discrepancy traces back to the fact that enough number of glueballs are not yet thermally excited at the critical temperature T_c \\simeq 280 MeV in quenched QCD due to the extremely small statistical factor as exp(-m_G/T_c) \\simeq 0.00207. This fact itself has a quite general nature independent of the particular choice of the effective model framework. We are thus arrive at a myste...
New insights on spectroscopy and properties of light hadrons with COMPASS
Haas Florian
2014-01-01
Full Text Available COMPASS is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron aimed at studying the structure and spectrum of hadrons. One main goal is the search for new hadronic states, in particular hybrid mesons and glueballs. Its large acceptance, high resolution, and high-rate capability make the COMPASS experiment an excellent device to study the spectrum of light-quark mesons in diffractive and central production up to masses of about 2.5 GeV/c2. COMPASS is able to measure final states with charged as well as neutral particles, so that resonances can be studied in different reactions and decay channels. During 2008 and 2009, COMPASS took a large data sample using 190 GeV/c negative and positive hadron beams on various targets. We present new results from the analyses of this data set. One focus lies on the search for new mesons in diffractively produced multi-particle final states. Here novel analysis methods are applied to study the dependence of partial waves on the squared four-momentum transfer t′ from the beam to the target. This also leads to a better separation of resonant and non-resonant contributions. Finally an update will be given on the recent analysis of the pion polarizability, which tests chiral dynamics.
Digital signal processing in the PANDA Electromagnetic Calorimeter
Kavatsyuk, Myroslav; Guliyev, Elmaddin; Tambave, Ganesh; Loehner, Herbert [KVI, University of Groningen (Netherlands); Collaboration: PANDA-Collaboration
2011-07-01
The PANDA collaboration at FAIR will employ antiproton annihilations to investigate yet undiscovered charm-meson states and glueballs. The aim is to study QCD phenomena in the non-perturbative regime and to unravel the origin of hadronic masses. A multi-purpose detector for tracking, calorimetry and particle identification is presently being developed to run at high luminosities providing up to 2.10{sup 7} interactions/s. One of the crucial components of the PANDA spectrometer is the EMC, composed of cooled PbWO{sub 4} crystals coupled to the Large Area Avalanche Photodiodes or Vacuum Photo-Triodes/Tetrodes. The photo-sensor signals are continuously digitized by the Sampling ADC (SADC) and analyzed on-line in the FPGA of the digitizer module to detect hits and extract energy and time information. Measurements with a prototype calorimeter were performed at the tagged-photon facility at MAMI-C, Mainz. The results demonstrate the excellent performance of the SADC readout, with energy resolutions better than achieved by analogue electronics and a sub-nanosecond time resolution. A fast on-line pile-up recovery algorithm has been developed. The layout of the complete digital read-out chain is presented, and results from applications in test experiments with the PANDA-EMC prototypes are reported.
García, Isabel García; March-Russell, John
2015-01-01
Dark matter (DM) without a matter asymmetry is studied in the context of Twin Higgs (TH) theories in which the LHC naturalness problem is addressed. These possess a twin sector related to the Standard Model (SM) by a (broken) $\\mathbb{Z}_2$ symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realisation of the TH mechanism, the Fraternal Twin Higgs, with only a single generation of twin quarks and leptons, and $SU(3)'\\times SU(2)'$ gauge group. We show that a variety of natural twin-WIMP DM candidates are present (directly linked to the weak scale by naturalness), the simplest and most attractive being the $\\tau^\\prime$ lepton with a mass $m_{\\tau^\\prime} > m_{\\rm Higgs}/2$, although spin-1 $W^{\\prime\\pm}$ DM and multicomponent DM are also possible (twin baryons are strongly disfavoured by tuning). We consider in detail the dynamics of the possibly (meta)stable glueballs in the twin sector, the nature of the twin QCD phase transition, and possible new contributions to th...
Experimental Considerations Motivated by the Diphoton Excess at the LHC
Agrawal, Prateek; Heidenreich, Ben; Reece, Matthew; Strassler, Matthew
2015-01-01
We consider the immediate or near-term experimental opportunities offered by some scenarios that could explain the new diphoton excess at the LHC. If the excess is due to a new particle $X_s$ at 750 GeV, additional new particles are required, providing further signals. If connected with naturalness, the $X_s$ may be produced in top partner decays. Then a $t'\\bar t'$ signal, with $t'\\to t X_s$ and $X_s\\to gg$ dominantly, might be discovered by reinterpreting 13 TeV SUSY searches in multijet events with low MET and/or a lepton. If $X_s$ is a bound state of quirks, the signal events may be accompanied by an unusual number of soft tracks or soft jets. Other resonances including dilepton and photon+jet as well as dijet may lie at or above this mass, and signatures of hidden glueballs might also be observable. If the "photons" in the excess are actually long-lived particles decaying to photon pairs or to electron pairs, there are opportunities for detecting overlapping photons and/or unusual patterns of apparent ph...
Experimental considerations motivated by the diphoton excess at the LHC
Agrawal, Prateek; Fan, JiJi; Heidenreich, Ben; Reece, Matthew; Strassler, Matthew
2016-06-01
We consider the immediate or near-term experimental opportunities offered by some scenarios that could explain the new diphoton excess at the LHC. If the excess is due to a new particle X s at 750 GeV, additional new particles are required, providing further signals. If connected with naturalness, the X s may be produced in top partner decays. Then a t^'overline{t}^' } signal, with t ' → tX s and X s → gg dominantly, might be discovered by reinterpreting 13 TeV SUSY searches in multijet events with low MET and/or a lepton. If X s is a bound state of quirks, the signal events may be accompanied by an unusual number of soft tracks or soft jets. Other resonances including dilepton and photon+jet as well as dijet may lie at or above this mass, and signatures of hidden glueballs might also be observable. If the "photons" in the excess are actually long-lived particles decaying to photon pairs or to electron pairs, there are opportunities for detecting overlapping photons and/or unusual patterns of apparent photon-conversions in either X s or 125 GeV Higgs decays. There is also the possibility of events with a hard "photon" recoiling against a narrow isolated HCAL-only "jet", which, after the jet's energy is corrected for its electromagnetic origin, would show a peak at 750 GeV.
Search for the decay X(3872)$\\to J/\\psi \\omega$ in the LHCb experiment at CERN
Capriotti, Lorenzo; Alves Jr, Antonio Augusto
In the Standard Model of particles, any non [$q\\bar{q}$] or [$qqq$] composite state is labelled as $\\textit{exotic}$: this includes different combinations which are in principle allowed (tetraquark, pentaquark, mesonic molecule, glueball, and other) but were never observed for a long time, up to 2003 when the Belle Collaboration at KEK reported the observation of a narrow peak in the $J/\\psi \\pi^+ \\pi^-$ invariant mass spectrum. The state, labelled as X(3872), must contain a $c\\bar{c}$ pair but its mass does not correspond exactly to any of the predicted states in the charmonium excitation spectrum. Several theoretical models have been developed to describe the nature of the X(3872), such as mesonic molecule, tetraquark, threshold effect, hybrid $c\\bar{c}g$ resonance, and others. After the Belle announcement, it was observed also by several others Collaborations (CDF, D0, BaBar, LHCb): BaBar observed evidence for the decay X(3872)$\\to J/\\psi \\omega$ at a rate comparable to that of $J/\\psi \\pi\\pi$, suggesting...
Olsen, Stephen Lars
2014-01-01
QCD-motivated models for hadrons predict an assortment of "exotic" hadrons that have structures that are more complex then the quark-antiquark mesons and three-quark baryons of the original quark-parton model. These include pentaquark baryons, the six-quark H-dibaryon, and tetra-quark, hybrid, and glueball mesons. Despite extensive experimental searches, no unambiguous candidates for any of these exotic configurations have yet to be identified. On the other hand, a number of meson states, one that seems to be a proton-antiproton bound state, and others that contain either charmed-anticharmed quark pairs or bottom-antibottom quark pairs, have been recently discovered that neither fit into the quark-antiquark meson picture nor match the expected properties of the QCD-inspired exotics. Here I briefly review results from a recent search for the H-dibaryon, and discuss some properties of the newly discovered states --the so-called XYZ mesons-- and compare them with expectations for conventional quark-antiquark mes...
Olsen, Stephen Lars
2014-01-01
QCD-motivated models for hadrons predict an assortment of "exotic" hadrons that have structures that are more complex than the quark-antiquark mesons and three-quark baryons of the original quark-parton model. These include pentaquark baryons, the six-quark H-dibaryon, and tetraquark, hybrid and glueball mesons. Despite extensive experimental searches, no unambiguous candidates for any of these exotic configurations have been identified. On the other hand, a number of meson states, one that seems to be a proton-antiproton bound state, and others that contain either charmed-anticharmed quark pairs or bottom-antibottom quark pairs, have been recently discovered that neither fit into the quark-antiquark meson picture nor match the expected properties of the QCD-inspired exotics. Here I briefly review results from a recent search for the H-dibaryon, and discuss some properties of the newly discovered states --the proton-antiproton state and the so-called XYZ mesons-- and compare them with expectations for convent...
Giacosa, Francesco
2016-01-01
The extended Linear Sigma Model (eLSM) is an effective model of QCD which includes in the mesonic sector (pseudo)scalar and (axial-)vector quarkonia mesons as well as one dilaton/glueball field and in the baryonic sector the nucleon doublet and its chiral partner in the mirror assignment. The chiral partner of the pion turns out to be the resonance $f_{0}(1370),$ which is then predominantly a quarkonium state. As a consequence, $f_{0}(500)$ is predominately not a quarkonium state but a four-quark object and is at first not part of the model. Yet, $f_{0}(500)$ is important in the baryonic sector and affects nuclear matter saturation, the high-density behavior, and nucleon-nucleon scattering. In these proceedings, we show how to enlarge the two-flavour version of the eLSM in order to include the four-quark field $f_{0}(500)$ in a chiral invariant manner. We then discuss homogeneous and inhomogeneous chiral restoration in a dense medium.
Meson spectroscopy with COMPASS
Nerling, Frank
2011-01-01
The COMPASS fixed-target experiment at CERN SPS is dedicated to the study of hadron structure and dynamics. In the physics programme using hadron beams, the focus is on the detection of new states, in particular the search for $J^{PC}$ exotic states and glueballs. After a short pilot run in 2004 (190 GeV/c negative pion beam, lead target), we started our hadron spectroscopy programme in 2008 by collecting an unprecedented statistics with a negative hadron beam (190 GeV/c) on a liquid hydrogen target. A similar amount of data with positive hadron beam (190 GeV/c) has been taken in 2009, as well as some additional data with negative beam on nuclear targets. The spectrometer features a large angular acceptance and high momentum resolution and also good coverage by electromagnetic calorimetry, crucial for the detection of final states involving $\\pi^0$ or $\\eta$. A first important result is the observation of a significant $J^{PC}$ spin exotic signal consistent with the disputed $\\pi_1(1600)$ in the pilot run dat...
Mamo, Kiminad A
2016-01-01
We study $\\mathcal{N} = 4$ super Yang-Mills theory on the Coulomb branch (cSYM) in the strong coupling limit by using the AdS/CFT correspondence. The dual geometry is the rotating black 3-brane Type IIB supergravity solution with a single non-zero rotation parameter $r_{0}$ which sets a fixed mass scale corresponding to the scalar condensate $\\,\\,\\sim r_{0}^4$ in the coulomb branch. We introduce a new ensemble where $T$ and $r_{0}$ are held fixed, and show that $r_{0}$ plays a similar role as $\\Lambda_{QCD}$. We compute the equation of state (EoS) of $\\mathcal{N} = 4$ cSYM at finite $T$, as well as the heavy quark-antiquark potential and the quantized mass spectrums of the scalar and spin-2 glueballs at $T=0$. By computing the Wilson loop (minimal surface) at $T=0$, we determine the heavy quark-antiquark potential $V(L)$ to be Cornell potential. At $T\
Braccini, S
2001-01-01
The K$^0_s$K$^0_s$ final state in two-photon collisions is studied with the L3 detector at LEP using data collected at centre of mass energies from 91 GeV to 202 GeV. The mass spectrum is dominated by the formation of the f$'_2$(1525) tensor meson in helicity two state. Clear evidence for destructive f$_2$-a$_2$ interference is observed. The first study of the f$_J$(1710) in two-photon collisions is presented. No signal has been observed in the region around 2.2 GeV and an upper limit for the two-photon partial width of the $\\xi$(2220) glueball candidate is derived. In the reaction $\\epem\\rightarrow\\epem$hadrons the inclusive production of $\\kos$ mesons is studied using data collected by the L3 detector at LEP centre of mass energies from 189 to 202 GeV. The differential production cross sections as a function of the transverse momentum and of the pseudorapidity are measured and a reasonable agreement is found between our measurement and the Next-to-Leading order QCD predictions.
Quantum parameter space and double scaling limits in N=1 super Yang-Mills theory
Ferrari, Frank
2003-04-01
We study the physics of N=1 super Yang-Mills theory with the gauge group U(N) and one adjoint Higgs field, by using the recently derived exact effective superpotentials. Interesting phenomena occur for some special values of the Higgs potential couplings. We find critical points with massless glueballs and/or massless monopoles, confinement without a mass gap, and tensionless domain walls. We describe the transitions between regimes with different patterns of gauge symmetry breaking, or, in the matrix model language, between solutions with a different number of cuts. The standard large N expansion is singular near the critical points, with domain wall tensions scaling as a fractional power of N. We argue that the critical points are four-dimensional analogues of the Kazakov critical points that are commonly found in low dimensional matrix integrals. We define a double scaling limit that yields the exact tension of BPS two-branes in the resulting N=1, four-dimensional noncritical string theory. D-brane states can be deformed continuously into closed string solitonic states, and vice versa, along paths that go over regions where the string coupling is strong.
Quantum parameter space and double scaling limits in N=1 super Yang-Mills theory
Ferrari, F
2003-01-01
We study the physics of N=1 super Yang-Mills theory with gauge group U(Nc) and one adjoint Higgs field, by using the recently derived exact effective superpotentials. Interesting phenomena occur for some special values of the Higgs potential couplings. We find critical points with massless glueballs and/or massless monopoles, confinement without a mass gap, and tensionless domain walls. We describe the transitions between regimes with different patterns of gauge symmetry breaking, or, in the matrix model language, between solutions with a different number of cuts. The standard large Nc expansion is singular near the critical points, with domain walls tensions scaling as a fractional power of Nc. We argue that the critical points are four dimensional analogues of the Kazakov critical points that are commonly found in low dimensional matrix integrals. We define a double scaling limit that yields the exact tension of BPS two-branes in the resulting N=1, four dimensional non-critical string theory. D-brane states...
First Results on Hadron Spectroscopy at COMPASS
Nerling, Frank
2010-01-01
The COMPASS fixed-target experiment at the CERN SPS is dedicated to the study of hadron structure and dynamics. One goal of the physics programme using hadron beams is the search for new states, in particular the search for $J^{PC}$ exotic states and glueballs. After a short pilot run in 2004 (190 GeV/c $\\pi^{-}$ beam, lead target), we started our hadron spectroscopy programme in 2008 by collecting unprecedented statistics using 190 GeV/c negative hadron beams on a liquid hydrogen target. A similar amount of data with 190 GeV/c positive hadron beams has been taken in 2009, as well as some data (negative beam) on nuclear targets. As a first result the observation of a significant $J^{PC}$ spin-exotic signal in the 2004 data -- consistent with the disputed $\\pi_1(1600)$ -- was recently published. Our spectrometer features good coverage by electromagnetic calorimetry, crucial for the detection of final states involving $\\pi^0$, $\\eta$ or $\\eta'$, and the 2008/09 data provide an excellent opportunity for the simu...
Notes on theta dependence in holographic Yang-Mills
Bigazzi, Francesco [INFN - Sezione di Pisa,Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Cotrone, Aldo L. [Dipartimento di Fisica e Astronomia, Università di Firenze and INFN - Sezione di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Sisca, Roberto [Università di Pisa, Dipartimento di Fisica “E. Fermi' ,Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy)
2015-08-18
Effects of the θ parameter are studied in Witten’s model of holographic 4d Yang-Mills, where θ is the coefficient of the CP-breaking topological term. First, the gravity background, including the full backreaction of the RR form dual to the θ parameter, is revisited. Then, a number of observables are computed holographically: the ground-state energy density, the string tension, the ’t Hooft loop, the light scalar glueball mass, the baryon mass scale, the critical temperature for deconfinement — and thus the whole (T,θ) phase diagram — and the entanglement entropy. A simple rule is provided to derive the θ corrections to (at least) all the CP-neutral observables of the model. Some of the observables we consider can and have been in fact studied in pure 4d Yang-Mills on the lattice. In that framework the results, obtained in the small θ regime, are given up to very few powers of θ{sup 2}. The corresponding holographic results agree qualitatively with available lattice data and signal an overall mass scale reduction by θ. Moreover, being exact in θ, they provide a benchmark for higher order corrections in Yang-Mills.
Collective String Interactions in AdS/QCD and High-Multiplicity pA Collisions
Iatrakis, Ioannis; Shuryak, Edward
2015-01-01
QCD strings originate from high-energy scattering in the form of Reggions and Pomerons, and have been studied in some detail in lattice numerical simulations. Production of multiple strings, with their subsequent breaking, is now a mainstream model of high energy $pp$ and $pA$ collisions. Recent LHC experiments revealed that high multiplicity end of such collisions show interesting collective effects. This ignited an interest in the interaction of QCD strings and multi-string dynamics. Holographic models, collectively known as AdS/QCD, developed in the last decade, describe both hadronic spectroscopy and basic thermodynamics, but so far no studies of the QCD strings have been done in this context. The subject of this paper is to do this. First, we study in more detail the scalar sector of hadronic spectroscopy, identifying "glueballs" and "scalar mesons," and calculate the degree of their mixing. The QCD strings, holographic images of the fundamental strings, thus have a "gluonic core" and a "sigma cloud." Th...
Large volumes and spectroscopy of walking theories
Del Debbio, L; Patella, A; Pica, C; Rago, A
2016-01-01
A detailed investigation of finite size effects is performed for SU(2) gauge theory with two fermions in the adjoint representation, which previous lattice studies have shown to be inside the conformal window. The system is investigated with different spatial and temporal boundary conditions on lattices of various spatial and temporal extensions, for two values of the bare fermion mass representing a {\\em heavy} and {\\em light} fermion regime. Our study shows that the infinite volume limit of masses and decay constants in the mesonic sector is reached only when the mass of the pseudoscalar particle $M_\\mathrm{PS}$ and the spatial lattice size $L$ satisfy the relation $L M_\\mathrm{PS} \\ge 15$. This bound, which is at least a factor of three higher than what observed in QCD, is a likely consequence of the different spectral signatures of the two theories, with the scalar isosinglet ($0^{++}$ glueball) being the lightest particle in our model. In addition to stressing the importance of simulating large lattice s...
Conformal vs confining scenario in SU(2) with adjoint fermions
Del Debbio, L; Patella, A; Pica, C; Rago, A
2009-01-01
The masses of the lowest-lying states in the meson and in the gluonic sector of an SU(2) gauge theory with two Dirac flavors in the adjoint representation are measured on the lattice at a fixed value of the lattice coupling $\\beta = 4/g_0^2 = 2.25$ for values of the bare fermion mass $m_0$ that span a range between the quenched regime and the massless limit, and for various lattice volumes. Even for light constituent fermions the lightest glueballs are found to be lighter than the lightest mesons. Moreover, the string tension between two static fundamental sources strongly depends on the mass of the dynamical fermions and becomes of the order of the inverse squared lattice linear size before the chiral limit is reached. The implications of these findings for the phase of the theory in the massless limit are discussed and a strategy for discriminating between the (near-)conformal and the confining scenario is outlined.
Hadron spectrum of QCD with one quark flavor
Farchioni, Federico; Muenster, Gernot; Sudmann, Tobias; Wuilloud, Jair [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Montvay, Istvan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Scholz, Enno E. [Brookhaven National Laboratory, Upton, NY (United States). Physics Dept.
2008-10-15
The latest results of an ongoing project for the lattice simulation of QCD with a single quark flavor are presented. The Symanzik tree-level-improvedWilson action is adopted in the gauge sector and the (unimproved)Wilson action for the fermion. Results from new simulations with one step of Stout-smearing ({rho}=0.15) in the fermion action are discussed. The one-flavor theory is simulated by a polynomial hybrid Monte Carlo algorithm (PHMC) at {beta}=4.0 corresponding to a=0.13 fm, on 16{sup 3}.32 and 24{sup 3} .48 lattices; the box-size is L{approx_equal}2.1 fm and L{approx_equal}3.1 fm, respectively. At the lightest simulated quark mass the (partially quenched) pion mass is {proportional_to} 300 MeV. The masses of the lightest bound states are computed, including the flavor singlet scalar and pseudoscalar mesons {sigma}{sub s} and {eta}{sub s}, the scalar glueball 0{sup ++}, and the {delta}{sup ++} baryon. Relics of SUSY in the mass spectrum, expected from a large N{sub c} orientifold equivalence with the N=1 supersymmetric Yang-Mills theory, are discussed. (orig.)
The infrared dynamics of Minimal Walking Technicolor
Del Debbio, Luigi; Patella, Agostino; Pica, Claudio; Rago, Antonio
2010-01-01
We study the gauge sector of Minimal Walking Technicolor, which is an SU(2) gauge theory with nf=2 flavors of Wilson fermions in the adjoint representation. Numerical simulations are performed on lattices Nt x Ns^3, with Ns ranging from 8 to 16 and Nt=2Ns, at fixed \\beta=2.25, and varying the fermion bare mass m0, so that our numerical results cover the full range of fermion masses from the quenched region to the chiral limit. We present results for the string tension and the glueball spectrum. A comparison of mesonic and gluonic observables leads to the conclusion that the infrared dynamics is given by an SU(2) pure Yang-Mills theory with a typical energy scale for the spectrum sliding to zero with the fermion mass. The typical mesonic mass scale is proportional to, and much larger than this gluonic scale. Our findings are compatible with a scenario in which the massless theory is conformal in the infrared. An analysis of the scaling of the string tension with the fermion mass towards the massless limit allo...
Large X Hadron Physics and Correlations with Central Region Phenomena
2002-01-01
The experiment uses a forward double-septum magnetic spectrometer with acceptance of @+~150~mrad to study the production of multiparticle systems. The system of mini-drift MWPC's has a processor which enables real-time selection of different multiplicities. The 32-cell Cherenkov counters along with the T.O.F. system allow the identification and separation of @p's, K's and p's over a large momentum range. A 3~m~x~3~m shower counter is installed to measure @p|0's and @g's traversing the spectrometer. \\\\ \\\\ A magnetic spectrometer installed at 90|0 measures identified single particles (T.O.F. and aerogel Cherenkov counters) and permits the measurement of flavour correlations with the forward spectrometer. Momentum selection of the 90|0 particles is incorporated in the trigger. .in +3 The experiment is data taking and studying such topics as 1) Production of @L^c|+ @A @L@p|+@p|+@p|- @A pK|-@p|+ 2) Glueball search in diffractive production of p @A pK|0^sK@+@p, pK|0^sK|0^s, p@L@L, etc... 3) p@*, pp comparison inclu...
Nicolescu, Basarab [LPNHE, Unite de Recherche des Universites Paris 6 et Paris 7, associee au CNRS, Theory Group, Universite Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)
2004-07-01
We consider several classes of analytic parametrizations of hadronic scattering amplitudes (the COMPETE analysis), and compare their predictions to all available forward data (pp, {pi}p, Kp, {gamma}p, {gamma}{gamma}, {sigma}p). Although these parametrizations are very close for {radical}s {>=} 9 GeV, it turns out that they differ markedly at low energy, where a universal Pomeron term {approx} ln{sup 2} s enables one to extend the fit down to {radical}s = 4 GeV. We present predictions on the total cross sections and on the ratio of the real part to the imaginary part of the elastic amplitude ({rho} parameter) for present and future pp colliders, and on total cross sections for {gamma}p {yields} hadrons at cosmic-ray energies and for it{gamma}{gamma} {yields} hadrons up to {radical}s = 1 TeV. The ln{sup 2} s behaviour of total cross sections, first obtained by Heisenberg 50 years ago, receives now increased interest both on phenomenological and theoretical levels. We present a modification of the Heisenberg's model in connection with the presence of glueballs and we show that it leads to a realistic description of all existing hadron total cross-sections data, in agreement with the COMPETE analysis.
The string-junction picture of multiquark states: an update
Rossi, Giancarlo; Veneziano, Gabriele
2016-01-01
We recall and update, both theoretically and phenomenologically, our (nearly) forty-years-old proposal of a string-junction as a necessary complement to the conventional classification of hadrons based just on their quark-antiquark constituents. In that proposal single (though in general metastable) hadronic states are associated with "irreducible" gauge-invariant operators consisting of Wilson lines (visualized as strings of color flux tubes) that may either end on a quark or an antiquark, or annihilate in triplets at a junction $J$ or an anti-junction $\\bar{J}$. For the junction-free sector (ordinary $q\\, \\bar{q}$ mesons and glueballs) the picture is supported by large-$N$ (number of colors) considerations as well as by a lattice strong-coupling expansion. Both imply the famous OZI rule suppressing quark-antiquark annihilation diagrams. For hadrons with $J$ and/or $\\bar{J}$ constituents the same expansions support our proposal, including its generalization of the OZI rule to the suppression of $J-\\bar{J}$ a...
The string-junction picture of multiquark states: an update
Rossi, G. C.; Veneziano, G.
2016-06-01
We recall and update, both theoretically and phenomenologically, our (nearly) forty-years-old proposal of a string-junction as a necessary complement to the conventional classification of hadrons based just on their quark-antiquark constituents. In that proposal single (though in general metastable) hadronic states are associated with "irreducible" gauge-invariant operators consisting of Wilson lines (visualized as strings of color flux tubes) that may either end on a quark or an antiquark, or annihilate in triplets at a junction J or an anti-junction overline{J} . For the junction-free sector (ordinary qoverline{q} mesons and glueballs) the picture is supported by large- N (number of colors) considerations as well as by a lattice strong-coupling expansion. Both imply the famous OZI rule suppressing quark-antiquark annihilation diagrams. For hadrons with J and/or overline{J} constituents the same expansions support our proposal, including its generalization of the OZI rule to the suppression of J-overline{J} annihilation diagrams. Such a rule implies that hadrons with junctions are "mesophobic" and thus unusually narrow if they are below threshold for decaying into as many baryons as their total number of junctions (two for a tetraquark, three for a pentaquark). Experimental support for our claim, based on the observation that narrow multiquark states typically lie below (well above) the relevant baryonic (mesonic) thresholds, will be presented.
Recent empirical developments in the study and understanding of XYZ states
Shen, Chengping
2016-07-01
Exotic hadronic states beyond the conventional quark model (called charmoniumlike/bottomoniumlike states or XYZ particles) have been searched for and many candidates were proposed including glueballs, hybrids, multi-quark states, hadron molecules, etc. Dramatic progress was made in the study of the exotic states after the running of the two B-factories, i.e., Belle at KEK and BaBar at SLAC. In my review report, I present the most recent results on the study of the XYZ states from the BESIII, Belle, BaBar, LHCb, CMS experiments, etc., including (1) X states: the observation of the X(3872) in e+e- → γX(3872) at around 4.26 GeV; searches for the Xb state; (2) Y states including the updated results for the Y(4008), Y(4260), Y(4360), Y(4660), etc; (3) Z states including the observations of the Z(4430), Z1(4050), Z2(4250), Zc(3900), Zc(4020), Zc(4200); the evidence for the Zc(4050)± → π±ψ(2S); search for the Zcs in e+e- → K+K-J/ψ.
Transverse Lattice Approach to Light-Front Hamiltonian QCD
Dalley, S
1999-01-01
We describe a non-perturbative procedure for solving from first principles the light-front Hamiltonian problem of SU(N) pure gauge theory in D spacetime dimensions (D>2), based on enforcing Lorentz covariance of observables. A transverse lattice regulator and colour-dielectric link fields are employed, together with an associated effective potential. We argue that the light-front vacuum is necessarily trivial for large enough lattice spacing, and clarify why this leads to an Eguchi-Kawai dimensional reduction of observables to 1+1-dimensions in the infinite N limit. The procedure is then tested by explicit calculations for 2+1-dimensional SU(infinity) gauge theory, within a first approximation to the lattice effective potential. We identify a scaling trajectory which produces Lorentz covariant behaviour for the lightest glueballs. The predicted masses, in units of the measured string tension, are in agreement with recent results from conventional Euclidean lattice simulations. In addition, we obtain the poten...
The Electromagnetic Calorimetry of the PANDA Detector at FAIR
Novotny, R. W.; PANDA Collaboration
2012-12-01
The PANDA collaboration at FAIR, Germany, will focus on undiscovered charm-meson states and glueballs in antiproton annihilations to study QCD phenomena in the non-perturbative regime. For fixed target experiments at the storage ring HESR a 4π-detector for tracking, particle ID and calorimetry is under development and construction to operate at high annihilation rates up to 20 MHz. The electromagnetic calorimeters are composed of a target spectrometer (EMC) based on PbWO4 crystals and a shashlyk-type sampling calorimeter at the most forward region. The EMC, comprising more than 15,000 crystals, is operated at a temperature of -25°C and read-out via large-area avalanche photo-diodes or vacuum phototriodes/tetrodes. The photo sensor signals are continuously digitized by sampling ADCs. More than 50% of the high quality PWO-II crystals are delivered and tested. The excellent performance with respect to energy, time and position information was determined over a shower energy range from 10 MeV up to 15 GeV by operating several prototype detectors. In addition, the concept of stimulated recovery has been investigated to recover radiation damage on- and off-line during the calorimeter operation. Besides the overall concept of the target spectrometer the response function of the shashlyk spectrometer down to photon energies even below 100 MeV is presented.
The holographic life of the {eta}'
Barbon, Jose L. F. [1 Theory Division, CERN, CH-1211, Geneva 23 (Switzerland); Hoyos, Carlos [Instituto de Fisica Teorica UAM/CSIC, C-XVI, and Departamento de Fisica Teorica, C-XI, Universidad Autonoma de Madrid, E-28049--Madrid (Spain); Mateos, David [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2J 2W9 (Canada)]. E-mail: dmateos@perimeterinstitute.ca; Myers, Robert C. [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2J 2W9 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
2004-10-01
In the string holographic dual of large-N{sub c} QCD with N{sub f} flavours, the {eta}' meson is massless at infinite N{sub c} and dual to a collective fluctuation of N{sub f} D6-brane probes in a supergravity background. Here we identify the string diagrams responsible for the generation of a mass of order N{sub f}/N{sub c}, consistent with the Witten-Veneziano formula, and show that the supergravity limit of these diagrams corresponds to mixings with pseudoscalar glueballs. We argue that the dependence on the {theta}-angle in the supergravity description occurs only through the combination {theta}+2(N{sub f}){sup 1/2} {eta}'/f{sub {pi}}, as dictated by the U(1){sub A} anomaly. We provide a quantitative test by computing the linear term in the {eta}' potential in two independent ways, with perfect agreement. (author)
COMPASS experiment at CERN open charm results and future hadron program
Kouznetsov, O
2009-01-01
COMPASS (COmmon Muon and Proton Apparatus for Structure and Spectroscopy) is a fixed target experiment at CERN dedicated to studies of the spin structure of the nucleon and of the spectroscopy of hadrons. During the years 2002–2004 and 2006–2007, the COMPASS collaboration has collected a large amount of data by scattering polarized 160 GeV/c muons on polarized 6LiD and NH3 targets. These data were used to evaluate the gluon contribution to the nucleon spin. The gluon polarization was directly measured from the cross-section helicity asymmetry of D0 mesons production in the photon-gluon fusion reaction. In 2008 COMPASS will perform a search for JPC-exotic mesons, glueballs or hybrids, through light hadron spectroscopy in high energy (190 GeV/c π−) pion-proton reactions using both centrally produced and diffractive events. Preliminary results from diffractive pion dissociation into a π−π−π+ final state obtained in 2004 are also discussed.
Dark matter in the hidden gauge theory
Yamanaka, Nodoka; Gongyo, Shinya; Iida, Hideaki
2014-01-01
The cosmological scenario of the dark matter generated in the hidden gauge theory based on the grand unification is discussed. It is found that the stability of the dark matter halo of our Galaxy and the cosmic ray observation constrain, respectively, the dark matter mass and the unification scale between the standard model and the hidden gauge theory sectors. To obtain a phenomenologically consistent thermal evolution, the entropy of the standard model sector needs to be increased. We therefore propose a scenario where the mini-inflation is induced from the potential coupled to the Standard model sector, in particular the Higgs sector. This scenario makes consistent the current dark matter density as well as the baryon-to-photon ratio for the case of pion dark matter. For the glueball or heavy pion of hidden gauge theory, an additional mini-inflation in the standard model sector before the leptogenesis is required. We also propose the possibility to confirm this scenario by known prospective experimental app...
Bajc, B; Mangano, G; Grumiller, D; Kummer, Wolfgang; Duff, Michael J; Liu, J T; Maceda, M; Madore, J
2004-01-01
Contents of Part 2: 11. Supersymmetric Grandunification and Fermion Masses (B. Bajc) 12. General Principles of Brane Kinematics and Dynamics (M. Pavsic) 13. Cosmological Neutrinos (G. Mangano) 14. The Problem of Mass (C.D. Froggatt) 15. How to Approach Quantum Gravity ... (D. Grumiller and W. Kummer) 16. Hidden Spacetime Symmetries and Generalized Holonomy in M-theory (M.J. Duff and J.T. Liu) 17. On the Resolution of Space-Time Singularities II (M. Maceda and J. Madore) 18. The Multiple Point Principle (D.L. Bennett and H.B. Nielsen) 19. Dynamics of Glue-Balls in N = 1 SYM Theory (L. Bergamin) 20. Quantization of Systems with Continuous Symmetries ... (M.V. Chichikina) 21. Singular Compactifications and Cosmology (L. Jaerv, T. Mohaupt and F. Saueressig) 22. Fundamental Physics and Lorentz Violation (R. Lehnert) 23. Functional Approach to Squeezed States ...(L. Musongela) 24. Constraining the Curvaton Scenario (M. Postma) 25. D-Branes and Unitarity of Noncommutative Field Theories (A. Torrielli) 26. Spinorial ...
Hadron spectroscopy with COMPASS - First results
Nerling, Frank
2010-01-01
The COMPASS experiment at CERN is dedicated to light hadron spectroscopy with emphasis on the detection of new states, in particular the search for spin exotic states and glueballs. After a short pilot run in 2004 (190 GeV/c $\\pi^{-}$ beam, Pb target) showing significant production strength of an exotic $J^{PC}=1^{-+}$ state at 1.66\\,GeV/${\\rm c^2}$, we have collected data with 190 GeV/c hadron beams on a liquid hydrogen target in 2008/09. The spectrometer features good coverage by calorimetry and our data provide excellent opportunity for simultaneous observation of new states in different decay modes. The diffractively produced $(3\\pi)^{-}$ system for example can be studied in both modes $\\pi^{-}p \\rightarrow \\pi^{-}\\pi^{+}\\pi^{-}p$ and $\\pi^{-}~p \\rightarrow \\pi^{-}\\pi^{0}\\pi^{0}~p$. Reconstruction of charged and neutral mode rely on completely different parts of the apparatus. Observation of new st ates in both modes provides important checks. The results on diffractive dissociation into 3$\\pi$ final stat...
Light-Meson Spectroscopy with COMPASS
Grube, Boris
2010-01-01
COMPASS is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron investigating the structure and spectrum of hadrons. One primary goal is the search for new hadronic states, in particular spin-exotic mesons and glueballs. After a short pilot run in 2004 with a 190 GeV/c $\\pi^-$ beam on a Pb target, which showed a significant spin-exotic $J^{PC} = 1^{-+}$ resonance consistent with the controversial $\\pi_1(1600)$, COMPASS collected large data samples with negative and positive hadron beams on H$_2$, Ni, W, and Pb targets in 2008 and 2009. We present results from a partial-wave analysis of diffractive dissociation of 190 GeV/c $\\pi^-$ into $\\pi^-\\pi^+\\pi^-$ final states on Pb and H$_2$ targets with squared four-momentum transfer in the range 0.1 < t' < 1 (GeV/c)^2. This reaction provides clean access to the light-quark meson spectrum up to masses of 2.5 GeV/c^2. A first comparison of the data from Pb and H$_2$ target shows a strong target dependence of the production strength of stat...
Haas, Florian
2009-01-01
QCD predicts four quark states or gluonic excitations like hybrids or glueballs to contribute to the meson spectrum in addition to $q\\overline{q}$ pair configurations. The most promising way to identify such states is the search for $J^{PC}$ quantum number combinations which are forbidden in the constituent quark model. The fixed target COMPASS experiment at CERN offers the opportunity to search for such states in the light quark sector with an unprecedented statistics. Diffractive reactions of 190 GeV/c pions on a lead target were studied by COMPASS during a pilot run in 2004. A Partial Wave Analysis (PWA) of the $\\pi^{−}\\pi^{−}\\pi^{+}$ final state with 42 waves including acceptance corrections through a phase-space Monte Carlo simulation of the spectrometer was performed. The exotic $\\pi_{1}$(1600) meson with quantum numbers $J^{PC}= 1^{−+}$ has been clearly established in the rho-pi decay channel with a mass of 1660 $\\pm$ 10(stat) MeV/c$^{2}$ and a width of 269 $\\pm$ 21(stat) MeV/c$^{2}$. The final s...
Study of B Meson Decays to ppbarh Final States
Hryn' ova, Tetiana B.; /SLAC
2006-03-22
B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X
Euclidean quantum field theory: Curved spacetimes and gauge fields
Ritter, William Gordon
This thesis presents a new formulation of quantum field theory (QFT) on curved spacetimes, with definite advantages over previous formulations, and an introduction to the millennium prize problem on four-dimensional gauge theory. Our constructions are completely rigorous, making QFT on curved spacetimes into a subfield of mathematics, and we achieve the first analytic control over nonperturbative aspects of interacting theories on curved spacetimes. The success of Euclidean path integrals to capture nonperturbative aspects of QFT has been striking. The Euclidean path integral is the most accurate method of calculating strong-coupling effects in gauge theory (such as glueball masses). Euclidean methods are also useful in the study of black holes, as evidenced by the Hartle-Hawking calculation of black-hole radiance. From a mathematical point of view, on flat spacetimes the Euclidean functional integral provides the most elegant method of constructing examples of interacting relativistic field theories. Yet until now, the incredibly-useful Euclidean path integral had never been given a definitive mathematical treatment on curved backgrounds. It is our aim to rectify this situation. Along the way, we discover that the Dirac operator on an arbitrary Clifford bundle has a resolvent kernel which is the Laplace transform of a positive measure. In studying spacetime symmetries, we discover a new way of constructing unitary representations of noncompact Lie groups. We also define and explore an interesting notion of convergence for Laplacians. The same mathematical framework applies to scalar fields, fermions, and gauge fields. The later chapters are devoted to gauge theory. We present a rigorous, self-contained introduction to the subject, aimed at mathematicians and using the language of modern mathematics, with a view towards nonperturbative renormalization in four dimensions. The latter ideas are unfinished. A completion of the final chapter would imply the construction
The experiment PANDA: physics with antiprotons at FAIR
Boca, Gianluigi
2015-05-01
PANDA is an experiment that will run at the future facility FAIR, Darmstadt, Germany. A high intensity and cooled antiproton beam will collide on a fixed hydrogen or nuclear target covering center-of-mass energies between 2.2 and 5.5 GeV. PANDA addresses various physics aspects from the low energy non-perturbative region towards the perturbative regime of QCD. With the impressive theoretical developments in this field, e.g. lattice QCD, the predictions are becoming more accurate in the course of time. The data harvest with PANDA will, therefore, be an ideal test bench with the aim to provide a deeper understanding of hadronic phenomena such as confinement and the generation of hadron masses. A variety of physics topics will be covered with PANDA, for example: the formation or production of exotic non-qqbar charm meson states connected to the recently observed XYZ spectrum; the study of gluon-rich matter, such as glueballs and hybrids; the spectroscopy of the excited states of strange and charm baryons, their production cross section and their spin correlations; the behaviour of hadrons in nuclear matter; the hypernuclear physics; the electromagnetic proton form factors in the timelike region. The PANDA experiment is designed to achieve the above mentioned physics goals with a setup with the following characteristics: an almost full solid angle acceptance; excellent tracking capabilities with high resolution (1-2 % at 1 GeV/c in the central region); secondary vertex detection with resolution ≈ 100 microns or better; electromagnetic calorimetry for detections of gammas and electrons up to 10 GeV; good particle identification of charge tracks (electrons, muons, pions, kaons, protons); a dedicated interchangeable central apparatus for the hypernuclear physics; detector and data acquisition system capable of working at 20 MHz interaction rate with an intelligent software trigger that can provide maximum flexibility.
Diphoton resonance from a new strong force
Georgi, Howard; Nakai, Yuichiro
2016-10-01
We explore a "partial unification" model that a new strong gauge group is combined with the ordinary color and hypercharge gauge groups. The VEV responsible for the combination is of the order of the S U (2 )×U (1 ) breaking scale, but the coupling of the new physics to standard model particles is suppressed by the strong interaction of the new gauge group. This simple extension of the standard model has a rich phenomenology, including composite particles of the new confining gauge interaction, a coloron and a Z' which are rather weakly coupled to standard model particles, and massive vector bosons charged under both the ordinary color and hypercharge gauge groups and the new strong gauge group. The new scalar glueball could be produced by gluon fusion and decay into two photons, both through loops of the new massive vector bosons. The simplest version of the model has some issues: the massive vector bosons are stable and the coloron and the Z' are strongly constrained by search data. An extension of the model to include additional fermions with the new gauge coupling, though not as simple and elegant, can address both issues and more. It allows the massive vector boson to decay into a colorless, neutral state that could be a candidate of the dark matter. And the coloron and Z' can decay dominantly into the new fermions, completely changing the search bounds. If the massive vector bosons are still long lived, they could form new bound states, "vector bosoniums" with additional interesting phenomenology. The model is an explicit example of how new physics at small scales could be hidden by strong interactions.
Highlights from Compass in hadron spectroscopy
Krinner, Fabian
2015-06-01
Since Quantum Choromdynamics allows for gluon self-coupling, quarks and gluons cannot be observed as free particles, but only their bound states, the hadrons. This so-called confinement phenomenon is responsible for 98% of the mass in the visible universe. Measurement of the hadron excitation spectra therefore gives valuable input for theory and phenomenology to quantitatively understand this phenomenon. One simple model to describe hadrons is the Constituent Quark Model (CQM), which knows two types of hadrons: mesons consisting of a quark and an antiquark and baryons, which are made of three quarks. More advanced models, which are inspired by QCD as well as calculations within Lattice QCD, predict the existence of other types of hadrons, which may be, e.g., described solely by gluonic excitations (glueballs) or mixed quark and gluon excitations (hybrids). In order to search for such states, the Compass experiment at the Super Proton Synchrotron at CERN has collected large data sets, which allow to study the light-quark meson and baryon spectra with unmatched precision. The overview shown here focuses on the light meson sector, presenting a detailed Partial-Wave Analysis of the processes: π- p → π-π+π- p and π- p → π-π0π0 p. A new state, the a1(1420) with JPC = 1++, is observed. Its Breit-Wigner parameters are found to be in the ranges: m = 1412 - 1422MeV/c2 and Γ = 130 - 150MeV/c2. In the same analysis, a signal in a wave with JPC = 1- + is observed. A resonant origin of this signal would not be explicable within the CQM. In addition to this possibility of an exotic state, possible non-resonant origin of this signal is discussed.
{bar p}p annihilation at rest into K{sub L}K{sup {plus_minus}}{pi}{sup {minus_plus}}
Abele, A.; Bischoff, S.; Bluem, P.; Djaoshvili, N.; Engelhardt, D.; Herbstrith, A.; Holtzhaussen, C.; Tischhaeuser, M. [Universitaet Karlsruhe, D-76021Karlsruhe (Germany); Adomeit, J.; Kaemmle, B.; Meier, J.; Schmidt, P.; Seibert, R.; Strohbusch, U. [Universitaet Hamburg, D-22761Hamburg (Germany); Amsler, C.; v. Dombrowski, S.; Giarritta, P.; Heinzelmann, M.; Ould-Saada, F.; Pietra, C.; Regenfus, C.; Spanier, S. [Universitaet Zuerich, CH-8057Zuerich (Switzerland); Baker, C.A.; Batty, C.J.; Pinder, C.N. [Rutherford Appleton Laboratory, Chilton, DidcotOX110QX (United Kingdom); Barnett, B.M.; Crede, V.; Ehmanns, A.; Herz, M.; Kalinowsky, H.; Klempt, E.; Pick, B.; Resag, S.; Strassburger, C.; Thoma, U.; Wittmack, K. [Universitaet Bonn, D-53115Bonn (Germany); Benayoun, M. [LPNHE Paris VI, VII, F-75252Paris (France); Berdoz, A.; McCrady, R.; Meyer, C.A. [Carnegie Mellon University, Pittsburgh, Pennsylvania15213 (United States); Beuchert, K.; Degener, T.; Koch, H.; Kunze, M.; Kurilla, U.; Luedemann, J.; Matthaey, H.; Peters, K.; Ratajczak, M.; Stoeck, H. [Universitaet Bochum, D-44780Bochum (Germany); Braune, K.; Cramer, O.; Duennweber, W.; Faessler, M.A.; Hessey, N.P.; Jamnik, D.; Kolo, C.; Roethel, W.; Voelcker, C.; Wallis, S.; Walther, D.; Wiedner, U.; Zupancic, C. [Universitaet Muenchen, D-80333Muenchen (Germany); Case, T.; Crowe, K.M.; Heinsius, F.H.; Kammel, P.; Lakata, M. [University of California, LBNL, Berkeley, California94720 (United States); Doser, M.; Kisiel, J.; Landua, R.; Montanet, L.; Ouared, R. [CERN, CH-1211Geneva4 (Switzerland); Haddock, R.P. [University of California, Los Angeles, California90024 (United States); Hidas, P. [Academy of Science, H-1525Budapest (Hungary); Suffert, M. [Centre de Recherches Nucleaires, F-67037Strasbourg (France)
1998-04-01
We present a measurement and partial wave analysis of the final state K{sub L}K{sup {plus_minus}}{pi}{sup {minus_plus}} of {bar p}p annihilation at rest in liquid hydrogen. This reaction is important for the study of the {bar K}K decay mode of scalar resonances, in particular, the isovectors a{sub 0}(980) and a{sub 0}(1450). The determination of the a{sub 0}(1450) production also fixes the {bar K}K coupling of the isoscalar f{sub 0}(1500) which is discussed as a glueball. We find B{bold (}{bar p}p{r_arrow}a{sub 0}(1450){pi};a{sub 0}(1450){r_arrow}{bar K}K{bold )}=(8.88{plus_minus}1.68){times}10{sup {minus}4} and hence B{bold (}{bar p}p{r_arrow}f{sub 0}(1500){pi};f{sub 0}(1500){r_arrow}{bar K}K{bold )}=(4.52{plus_minus}0.36){times}10{sup {minus}4}. The mass and width of a{sub 0}(1450) are m=1480{plus_minus}30MeV/c{sup 2} and {Gamma}=265{plus_minus}15MeV/c{sup 2}, respectively. For a{sub 0}(980) we determine the relative ratio B({bar p}p{r_arrow}a{sub 0}{pi};a{sub 0}{r_arrow}{bar K}K)/B({bar p}p{r_arrow}a{sub 0}{pi};a{sub 0}{r_arrow}{pi}{eta}) =0.23{plus_minus}0.05 and its relative coupling, {bar K}K to {pi}{eta}, is 1.03{plus_minus}0.14. {copyright} {ital 1998} {ital The American Physical Society}
On the stability of multiscale models of dynamical symmetry breaking from holography
Faedo, Anton F. [Department of Physics, College of Science, Swansea University, Singleton Park, Swansea, Wales (United Kingdom); Departament de Física Fonamental and Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona (Spain); Piai, Maurizio; Schofield, Daniel [Department of Physics, College of Science, Swansea University, Singleton Park, Swansea, Wales (United Kingdom)
2014-03-15
We consider two classes of backgrounds of Type IIB supergravity obtained by wrapping D5-branes on a two-cycle inside the conifold. The field theory dual exhibits confinement and, in addition, a region in which the dynamics is walking, at least in the weak sense that the running of the coupling is anomalously slow. We introduce quenched matter in the fundamental, modeled by probe D7-branes which wrap an internal three-dimensional manifold and lie at the equator of the transverse two-sphere. In the space spanned by the remaining internal angle and the radial coordinate, the branes admit two embeddings. The first one is U-shaped: the branes merge at some finite value of the radius. The second one is disconnected and extends along the entire radial direction at fixed angular separation. We interpret these two configurations as corresponding to chiral-symmetry breaking and preserving phases, respectively. We present a simple diagnostic tool to examine the classical stability of the embedding, based on the concavity/convexity conditions for the relevant thermodynamic potentials. We use this criterion to show that U-shaped probes that explore the walking region are unstable, hence providing a dynamical origin for the tachyonic mode found in the literature. Whenever this occurs, the disconnected solution becomes favored energetically. We find that in one of the two classes of backgrounds the U-shaped embedding is always unstable, and thus never realized dynamically. Consequently, these models cannot be used to describe chiral-symmetry breaking. In the second category of solutions, our analysis reveals the presence of a first-order phase transition between chiral-symmetry broken and restored phases. Interestingly, this is in the same class that contains a parametrically light scalar in the spectrum of glueballs of the dual field theory.
Phase diagrams of exceptional and supersymmetric lattice gauge theories
Wellegehausen, Bjoern-Hendrik
2012-07-10
In this work different strongly-coupled gauge theories with and without fundamental matter have been studied on the lattice with an emphasis on the confinement problem and the QCD phase diagram at nonvanishing net baryon density as well as on possible supersymmetric extensions of the standard model of particle physics. In gauge theories with a non-trivial centre symmetry, as for instance SU(3)-Yang-Mills theory, confinement is intimately related to the centre of the gauge group, and the Polyakov loop serves as an order parameter for confinement. In QCD, this centre symmetry is explicitly broken by quarks in the fundamental representation of the gauge group. But still quarks and gluons are confined in mesons, baryons and glueballs at low temperatures and small densities, suggesting that centre symmetry is not responsible for the phenomenon of confinement. Therefore it is interesting to study pure gauge theories without centre symmetry. In this work this has been done by replacing the gauge group SU(3) of the strong interaction with the exceptional Lie group G{sub 2}, that has a trivial centre. To investigate G{sub 2} gauge theory on the lattice, a new and highly efficient update algorithm has been developed, based on a local HMC algorithm. Employing this algorithm, the proposed and already investigated first order phase transition from a confined to a deconfined phase has been confirmed, showing that indeed a first order phase transition without symmetry breaking or an order parameter is possible. In this context, also the deconfinement phase transition of the exceptional Lie groups F4 and E6 in three spacetime dimensions has been studied. It has been shown that both theories also possess a first order phase transition.
Leyhe, Michael
2013-07-09
The present thesis deals with two experiments, which perform on the field of the hadron spectroscopy fundamental research. These are the existing BES III experiment, from which data from charmonium decay are analyzed and the future PANDA experiment, for which in this thesis the readout of the forward end cap of the electromagnetic calorimeter is developed. In the first part the radiative decays of ψ(2S) and J/ψ into γ(π{sup +}π{sup -}η) are analyzed for the study of the η(1405) meson. This state is considered as possible glueball candidate, because among others the pseudoscalar-meson nonet with the η(1405), η(1295), and η(1475) is overoccupied by one particle and other experiments assign to the η(1405) a large gluonic contribution. The production of the η(1475) can, as confirmed by other experiments, ot be observed in the decay into π{sup +}π{sup -}η.The η(1295) however is identified in the framework of a partial-wave analysis in the decay J/ψ→γπ{sup +}π{sup -}η. This succeeded previously only in the DM2 experiment, indeed with distinctly lower statistics and corresponding uncertainties. A possible solution of the problem of the overoccupation, the non-existence of the η(1295), cannot be confirmed by the results presented in this thesis. Furthermore the branching ratios of different decays are determined. The high event-rate allows to determine some decay probabilities for the first time respectively clearly more precisely. The partial waves contributing in the decay J/ψ→γπ{sup +}π{sup -}η can be determined by a mass-independent partial-wave analysis and brought into connection with known resonances. In the second part of the thesis the development and optimization of the photodetector-preamplifier units used for the readout of the forward end cap of the electromagnetic calorimeter are shown. A manifold of these detector-units were produced for a prototype of the forward end cap and tested in subsequent test-beam times under real
Applications of instantons to hadronic processes
Zetocha, Valeriu Ioan
Instantons constitute an important part of QCD as they provide a way to reach beyond the perturbative region. In the introductory chapters we present the ideas that constitute the backbone of instanton computation on a simple standard integral. We then turn our attention to QCD instantons and briefly show the steps to compute the effective lagrangian. The effective lagrangian is then used as a main tool for studying instanton contributions to hadronic decays of the scalar glueball, the pseudoscalar charmonium state etac, and the scalar charmonium state chic. Hadronic decays of the eta c are of particular interest. The three main decay channels are KK¯pi, etapipi and eta'pipi, each with an unusually large branching ratio of ˜5%. We show that the total decay rate into three pseudoscalar mesons can be reproduced using an instanton size distribution consistent with phenomenology and lattice results. Instantons correctly reproduce the ratio B(etapipi)/ B(eta'pipi) but over-predict the ratio B(KK¯pi)/B(etapipi). In the next part we study the contribution of instantons to OZI violation in the axial-vector channel. We consider, in particular, the f1-a 1 meson splitting, the flavor singlet and triplet axial coupling of a constituent quark, and the axial coupling constant of the nucleon. Instantons provide a short distance contribution to OZI violating correlation functions which is repulsive in the f1 meson channel and adds to the flavor singlet three-point function of a constituent quark. We compute long distance contributions using numerical simulations of the instanton liquid. We find that the iso-vector axial coupling constant of a constituent quark is (g A3)Q = 0.9 and that of a nucleon is g A3 = 1.28, in good agreement with experiment. The flavor singlet coupling of quark is close to one, while that of a nucleon is suppressed gA0 = 0.8. This number is still significantly larger than the experimental value gA0 = (0.28--0.41). In the last part we present an algorithm
N Physics - Proceedings of the Fourth Cebaf/int Workshop
Lee, T.-S. H.; Roberts, W.
1997-06-01
The Table of Contents for the book is as follows: * Introduction * Preface * Baryons and QCD * Dispersion Relations in Pion Photoproduction * Reaction Theories for N* Excitations in πN and γN Reactions * The N* Physics Program: Where are We and Where are We Going? * Recent Calculations of Electromagnetic and Strong Decays of N* * Test of Constituent Quark Model in η and π Photoproduction * Baryon Current Matrix Elements in a Relativistic Quark Model * Light-Front Calculations of Electromagnetic Form Factors for N-N* Transitions * Open Problems in Hadronic Structure * The Role of Massive States in Chiral Perturbation Theory * Baryons in Chiral Constituent Quark Model * Delta Electroproduction in a Chiral Bag Model Approach * E2/M1 and C2/M1 in the Electroproduction of the Δ and the Chiral Quark Soliton Model * Monopole Excitations of Baryons in the NJL Soliton Model * Δ Photoproduction in Chiral Color Dielectric Model * Glueballs and Hybrids * Pion Photo-Production and the Off-Shell Behavior of the πN Interaction * Kaon Photoproduction on the Nucleon: Status and Future Prospects * Determination of N* Parameters in the Review of Particle Properties * N* Physics at the AGS with the Crystal Ball Multiphoton Spectrometer * Photoexcitation of the S11(1535)-Resonance on the Proton, on the Neutron, and in Nuclei * Measurement of the E2/M1 Ratio in the N → Δ Transition * Theory of Eta Photo- and Electroproduction * Vector Mesons Below 2 GeV * N* Resonances and 2π Production * A Model for Two-Pion Photoproduction Amplitudes * Negative Parity Baryons in the QCD Sum Rule * Meson Photoproductions Off Nucleons in the Chiral Quark Model * Unquenching the Quark Model * Spin Observables in Pseudoscalar Meson Photoproduction * Baryon Resonance Extraction from πN Data using a Multichannel Unitary Model * A Dispersion Theoretical Analysis of the E/M Ratio of the Δ(1232) Resonance * Meson Production Experiments at TJNAL and BNL * Opportunities for Polarization Physics with
Radiative decays of the psi(3097) to two meson final states
Einsweiler, K.F.
1984-05-01
The MARK III detector operating at the SPEAR storage ring has acquired a sample of 2.7 x 10/sup 6/ produced psi(3097)'s. These events are used to investigate the radiative decays of the psi to two meson final states. Such decays are of topical interest because of the unusual QCD laboratory they provide - of particular interest is the possibility of observing glueball states. The process psi ..-->.. ..gamma pi../sup +/..pi../sup -/ is studied. The f(1270) tensor meson is observed and the helicity structure of its production is measured. The data indicate that helicity 2 is suppressed, in disagreement with lowest order QCD calculations. Evidence is presented for the first observation of the theta(1700) in the ..pi../sup +/..pi../sup -/ final state. The strong, but not complete, suppression of this state in the ..pi pi.. channel, combined with the absence of a J/sup P/ = 2/sup +/ signal in a recent MARK III analysis of psi ..-->.. ..gamma.. rho rho, suggest a very mysterious nature for the theta(1700). The process psi ..-->.. ..gamma..K/sup +/K/sup -/ is also studied. The f'(1515) tensor meson is observed with a branching ratio in agreement with the SU(3) symmetry prediction for the standard two gluon radiative decay diagram with no mixing corrections. The helicity structure of the f'(1515) is measured for the first time, and is found to be similar to that of the f(1270). The theta(1700) is observed with high statistics. Its spin and parity are measured, with the result that J/sup P/ = 2/sup +/ is preferred over J/sup P/ = 0/sup +/ at the 99.9% C.L. In addition, evidence is presented for a remarkable narrow state, designated the xi(2220). Its parameters are measured to be: m = 2.218 +- 0.003 +- 0.010 GeV, GAMMA less than or equal to 0.040 GeV at 95% C.L., and BR(psi ..-->.. ..gamma..xi(2220))BR(xi(2220) ..-->.. K/sup +/K/sup -/) = (5.7 +- 1.9 +- 1.4) x 10/sup -5/.
Aspects of Pure Quantum Chromodynamics on Large Lattices.
Ford, Ian John
1987-09-01
Available from UMI in association with The British Library. Requires signed TDF. We use Monte Carlo methods to study pure quantum chromodynamics on a four-dimensional Euclidean spacetime lattice consisting of 32^4 points. The features we investigate are relevant to hadron spectroscopy. We take values of the bare coupling beta equal to 6.29, 6.585 and 6.88 in order to monitor the approach towards the continuum limit of the lattice system. To exploit the available Monte Carlo configurations as far as possible, we study correlation functions of extended operators whose overlap with the required lattice state is enhanced. Through the correlations of improved quarkonium operators and also through those of extended Polyakov lines we study the potential between static triplet and antitriplet colour charges (which represent a heavy quark and antiquark). The resulting string tensions do not vary with beta according to the expectations of asymptotic scaling, and consequently it is not possible to confirm that our lattices exhibit continuum behaviour. With similar methods we investigate the potential between two static octet colour charges, the potential between sextet and antisextet colour charges and also the energies of static quark and antiquark systems which have E_{u} and A_{1u} excitations of the gluon field. We also calculate the masses of glueballs with J^{PC} of 0 ^{++} and 2^{++ } using these extended operator techniques. The 32^4 lattice configurations are supplemented by additional configurations of a 10 ^4 lattice at beta = 6.0 and a 20^4 lattice at beta = 6.2 for a study of the spin-dependent corrections to the non-relativistic potential between a heavy quark and antiquark. One of the two spin-orbit potentials, V_1, is found to have long range behaviour, whilst the other, V_2, and the tensor and scalar spin-spin potentials (V _3 and V_4 respectively) are short range. The pattern of this behaviour is consistent with scalar confinement and a vector Coulomb
Meson Spectroscopy in the Light Quark Sector
De Vita, R.; Lunardi, S.; Bizzeti, P. G.; Bucci, C.; Chiari, M.; Dainese, A.; Di Nezza, P.; Menegazzo, R.; Nannini, A.; Signorini, C.; Valiente-Dobon, J. J.
2014-01-01
Understanding the hadron spectrum is one of the fundamental issues in modern particle physics. We know that existing hadron configurations include baryons, made of three quarks, and mesons, made of quark-antiquark pairs. However most of the mass of the hadrons is not due to the mass of these elementary constituents but to their binding force. Studying the hadron spectrum is therefore a tool to understand one of the fundamental forces in nature, the strong force, and Quantum Chromo Dynamics (QCD), the theory that describes it. This investigation can provide an answer to fundamental questions as what is the origin of the mass of hadrons, what is the origin of quark confinement, what are the relevant degrees of freedom to describe these complex systems and how the transition between the elementary constituents, quarks and gluons, and baryons and mesons occurs. In this field a key tool is given by meson spectroscopy. Mesons, being made by a quark and an anti-quark, are the simplest quark bound system and therefore the ideal benchmark to study the interaction between quarks and understand what the role of gluons is. In this investigation, it is fundamental to precisely determine the spectrum and properties of mesons but also to search for possible unconventional states beyond the configuration q{anti q} as tetraquarks (qq{anti qq}), hybrids (q{anti q}g) and glueballs. These states can be distinguished unambiguously from regular mesons when they have exotic quantum numbers, i.e. combinations of total angular momentum, spin and parity that are not allowed for q{anti q} states. These are called exotic quantum numbers and the corresponding states are referred to as exotics. The study of the meson spectrum and the search for exotics is among the goals of several experiments in the world that exploit different reaction processes, as e{sup +}e{sup -} annihilation, p{anti p} annihilation, pion scattering, proton-proton scattering and photo-production, to produce meson states
The meson spectroscopy program with CLAS12 at Jefferson Laboratory
Rizzo, Alessandro [Univ. of Rome Tor Vergata (Italy)
2016-06-01
The study of the hadronic spectrum is one of the most powerful tools to investigate the mechanism at the basis of quark confinement within hadrons. A precise determination of the spectrum allows not only to assess the properties of the hadrons in their fundamental and excited states, but also to investigate the existence of states resulting from alternative configurations of quarks and gluons, such as the glue-balls, hybrid hadrons and many-quarks configurations. The study of the mesonic part of the spectrum can play a central role in this investigation thanks to the strong signature that the hybrid mesons are expected to have: the presence of explicit gluonic degrees of freedom in such states may result in JPC configurations not allowed for the standard q ¯ q states. From the experimental side the expected high-multiplicity decays of the hybrid mesons require an apparatus with high performances in terms of rate-capability, resolution and acceptance. The CLAS12 experiment (formally MesonEx) is one of new-generation experiments at Thomas Jefferson National Laboratory (JLAB) for which an unprecedented statistics of events, with fully reconstructed kinematics for large particle multiplicity decays, will be available. A wide scientific program that will start in 2016 has been deployed for meson spectrum investigation with the CLAS12 apparatus in Hall B at energies up to 11 GeV. One of the main parts of the program is based on the use of the Forward Tagger apparatus, which will allow CLAS12 experiment to extend the study of meson electro-production to the quasi-real photo-production kinematical region (very low Q2), where the production of hybrid mesons is expected to be favoured. The data analysis which is required to extract the signal from hybrid states should go beyond the standard partial wave analysis techniques and a new analysis framework is being set up through the international network Haspect. The Haspect Network gathers people involved into theoretical and
Probing a new strongly interacting sector via composite diboson resonances
Ko, P.; Yu, Chaehyun; Yuan, Tzu-Chiang
2017-06-01
Diphoton resonance was a crucial discovery mode for the 125 GeV Standard Model Higgs boson at the Large Hadron Collider (LHC). This mode or the more general diboson modes may also play an important role in probing for new physics beyond the Standard Model. In this paper, we consider the possibility that a diphoton resonance is due to a composite scalar or pseudoscalar boson, whose constituents are either new hyperquarks Q or scalar hyperquarks Q ˜ confined by a new hypercolor force at a confinement scale Λh. Assuming the mass mQ (or mQ ˜) ≫Λh, a diphoton resonance could be interpreted as either a Q Q ¯ (1S0) state ηQ with JP C=0-+ or a Q ˜ Q˜ †(1S0) state ηQ ˜ with JP C=0++. For the Q Q ¯ scenario, there will be a spin-triplet partner ψQ which is slightly heavier than ηQ due to the hyperfine interactions mediated by hypercolor gluon exchange; while for the Q ˜Q˜† scenario, the spin-triplet partner χQ ˜ arises from higher radial excitation with nonzero orbital angular momentum. We consider productions and decays of ηQ, ηQ ˜, ψQ, and χQ ˜ at the LHC using the nonrelativistic QCD factorization approach. We discuss how to test these scenarios by using the Drell-Yan process and the forward dijet azimuthal angular distributions to determine the JP C quantum number of the diphoton resonance. Constraints on the parameter space can be obtained by interpreting some of the small diphoton "excesses" reported by the LHC as the composite scalar or pseudoscalar of the model. Another important test of the model is the presence of a nearby hypercolor-singlet but color-octet state like the 1S0 state ηQ8 or ηQ˜8, which can also be constrained by dijet or monojet plus monophoton data. Both possibilities of a large or small width of the resonance can be accommodated, depending on whether the hyper-glueball states are kinematically allowed in the final state or not.
Lattice QCD Calculation of Nucleon Structure
Liu, Keh-Fei [University of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy; Draper, Terrence [University of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy
2016-08-30
decomposition and the strange quark spin from the anomalous Ward identity. Recently, we have started to include multiple lattices with different lattice spacings and different volumes including large lattices at the physical pion mass point. We are getting quite close to being able to calculate the hadron structure at the physical point and to do the continuum and large volume extrapolations, which is our ultimate aim. We have now finished several projects which have included these systematic corrections. They include the leptonic decay width of the ρ, the πN sigma and strange sigma terms, and the strange quark magnetic moment. Over the years, we have also studied hadron spectroscopy with lattice calculations and in phenomenology. These include Roper resonance, pentaquark state, charmonium spectrum, glueballs, scalar mesons a_{0}(1450) and σ(600) and other scalar mesons, and the 1^{-+} meson. In addition, we have employed the canonical approach to explore the first-order phase transition and the critical point at finite density and finite temperature. We have also discovered a new parton degree of freedom -- the connected sea partons, from the path-integral formulation of the hadronic tensor, which explains the experimentally observed Gottfried sum rule violation. Combining experimental result on the strange parton distribution, the CT10 global fitting results of the total u and d anti-partons and the lattice result of the ratio of the momentum fraction of the strange vs that of u or d in the disconnected insertion, we have shown that the connected sea partons can be isolated. In this final technical report, we shall present a few representative highlights that have been achieved in the project.
Lattice QCD Calculation of Nucleon Structure
Liu, Keh-Fei; Draper, Terrence
2016-08-30
meson mass decomposition [16] and the strange quark spin from the anomalous Ward identity [17]. Recently, we have started to include multiple lattices with di erent lattice spacings and di erent volumes including large lattices at the physical pion mass point. We are getting quite close to being able to calculate the hadron structure at the physical point and to do the continuum and large volume extrapolations which is our ultimate aim. We have now nished several projects which have included these systematic corrections. They include the leptonic decay width of the [18], the N sigma and strange sigma terms [19], and the strange quark magnetic moment [20]. Over the years, we have also studied hadron spectroscopy with lattice calculations and in phenomenology. These include Roper resonance [21, 22], pentaquark state [23], charmonium spectrum [24, 14], glueballs [25, 26, 27, 28], scalar mesons a0(1450) and (600) [29] and other scalar mesons [30], and the 1+ meson [31]. In addition, we have employed the canonical approach to explore the rst order phase transition and the critical point at nite density and nite temperature [32, 33]. We have also discovered a new parton degree of freedom { the connected sea partons, from the path-integral formulation of the hadronic tensor [34, 35] which explains the experimentally observed Gottfried sum rule violation [34]. Combining experimental result on the strange parton distribution, the CT10 global tting results of the total u and d anti-partons and the lattice result of the ratio of the momentum fraction of the strange vs that of u or d in the disconnected insertion, we have shown that the connected sea partons can be isolated [36]. In this nal technical report, we shall present a few representative highlights that have been achieved in the project.
Suganuma, H.; Fukushima, M.; Toki, H.
-diagonal Gluon Phase in the Maximally Abelian Gauge * On the Colour Confinement and the Minimal Surface * Glueball Mass and String Tension of SU(2) Gluodynamics from Abelian Monopoles and Strings * Application of the Non-Perturbative Renormalization Group to the Nambu-Jona-Lasinio Model at Finite Temperature and Density * Confining Flux-Tube and Hadrons in QCD * Gauge Symmetry Breakdown due to Dynamical Higgs Scalar * Spatial Structure of Quark Cooper Pairs * New Approach to Axial Coupling Constants in the QCD Sum Rule and Instanton Effects * String Breaking on a Lattice * Bethe-Salpeter Approach for Mesons within the Dual Ginzburg-Landau Theory * Gauge Dependence and Matching Procedure of a Nonrelativistic QCD Boundstate Formalism * A Mathematical Approach to the SU(2)-Quark Confinement * Simulations of Odd Flavors QCD by Hybrid Monte Carlo * Non-Perturbative Renormalization Group Analysis of Dynamical Chiral Symmetry Breaking with Beyond Ladder Contributions * Charmonium Physics in Finite Temperature Lattice QCD * From Meson-Nucleon Scattering to Vector Mesons in Nuclear Matter * Symposium Program * List of Participants
Bound states and critical behavior of the Yukawa potential
LI; Yongyao
2006-01-01
,S.,Ivlev,A.,Morfill,G.et al.,Scattering in the attractive Yukawa potential in the limit of strong interaction,Phys.Rev.Lett.,2003,90:225002.[18]Iorio,L.,Constraints to a Yukawa gravitational potential from laser data to LAGEOS satellites,Phys.Lett.A,2002,298:315-318.[19]Gregory,E.,Guo,S.,Kr(o)ger,H.et al.,Hamiltonian lattice QCD at finite chemical potential,Phys.Rev.D,2000,62:054508.[20]Luo,X.Q.,Gregory,E.,Guo,S.et al.,QCD at Finite Density:in Non-Perturbative Methods and Lattice QCD,Singapore:World Scientific,2001,138-149.[21]Fang,Y.,Luo,X.Q.,Hamiltonian lattice quantum chromodynamics at finite density with Wilson fermions,Phys.Rev.D,2004,69:114501.[22]Luo,X.Q.,Tricritical point of lattice QCD with Wilson quarks at finite temperature and density,Phys.Rev.D,2004,70,091504.[23]Press,W.,Teukolsky,S.,Vetterling,W.et al.,Numerical Recipes in C,Cam-bridge:Can bridge University Press,1992.[24]Jirari,H.,Kr(o)ger,H.,Luo,X.Q.et al.,Monte Carlo Hamiltonian,Phys.Lett.A,1999:258:6-14.[25]Metropolis,N.,Rosenbluth,A.,Rosenbluth,M.et al.,Equation of state calculations by fast computing machines,J.Chem.Phys.,1953,21:1087-1092.[26]Luo,X.Q.,Chen,Q.,Estimate for the 0++ glueball mass in QCD,Mod.Phys.Lett.A,1996,11:2435-2442.[27]Luo,X.Q.,Chen,Q.,Guo,S.et al.,Glueball masses in quantum chromodynamics,Nucl.Phys.B,1997,53:243-245.[28]Luo,X.Q.,Huang,C.,Jiang,J.et al.,Monte Carlo Hamiltonian-from statistical physics to quantum theory,Physica A,2000,281:201-206.[29]Luo,X.Q.,Huang,C.,Jiang,J.et al.,Quantum theory with many degrees of freedom from Monte Carlo Hamiltonian,Nucl.Phys.B,2000,83:810-812.[30]Jirari,H.,Kr(o)ger,H.,Huang,C.et al.,Monte Carlo Hamiltonian,Nucl.Phys.B,2000,83:953-955.[31]Jiang,J.,Huang,C.,Luo,X.Q.et al.,Hamiltonian Monte Carlo application to (2+1)-dimensional quantum mechanics,Commun.Theor.Phys.,2000,34:723-728.[32]Huang,C.,Jiang,J.,Luo,X.Q.et al.,Monte Carlo effective Hamiltonian in (1+ 1)-dimensional case,High Energy Phys.Nucl.Phys.,2000,24:478-483.[33]Luo,X.Q.,Xu,H.,Yang,J.et al.,(3
Fortran code for SU(3) lattice gauge theory with and without MPI checkerboard parallelization
Berg, Bernd A.; Wu, Hao
2012-10-01
.5. Nature of problem: Physics of pure SU(3) Quantum Field Theory (QFT). This is relevant for our understanding of Quantum Chromodynamics (QCD). It includes the glueball spectrum, topological properties and the deconfining phase transition of pure SU(3) QFT. For instance, Relativistic Heavy Ion Collision (RHIC) experiments at the Brookhaven National Laboratory provide evidence that quarks confined in hadrons undergo at high enough temperature and pressure a transition into a Quark-Gluon Plasma (QGP). Investigations of its thermodynamics in pure SU(3) QFT are of interest. Solution method: Markov Chain Monte Carlo (MCMC) simulations of SU(3) Lattice Gauge Theory (LGT) with the Wilson action. This is a regularization of pure SU(3) QFT on a hypercubic lattice, which allows approaching the continuum SU(3) QFT by means of Finite Size Scaling (FSS) studies. Specifically, we provide updating routines for the Cabibbo-Marinari heatbath with and without checkerboard parallelization. While the first is suitable for pedagogical purposes and small scale projects, the latter allows for efficient parallel processing. Targetting the geometry of RHIC experiments, we have implemented a Double-Layered Torus (DLT) lattice geometry, which has previously not been used in LGT MCMC simulations and enables inside and outside layers at distinct temperatures, the lower-temperature layer acting as the outside boundary for the higher-temperature layer, where the deconfinement transition goes on. Restrictions: The checkerboard partition of the lattice makes the development of measurement programs more tedious than is the case for an unpartitioned lattice. Presently, only one measurement routine for Polyakov loops is provided. Unusual features: We provide three different versions for the send/receive function of the MPI library, which work for different operating system +compiler +MPI combinations. This involves activating the correct row in the last three rows of our latmpi.par parameter file. The
Proceedings of the 29th International Conference on High Energy Physics: Ichep '98 (in 2 Volumes)
Astbury, Alan; Axen, David; Robinson, Jacob
1999-06-01
with the CMD-2 Detector * A New Search for Direct CP Violation in Hyperon Decays * Pa-07 Production and Decay of Heavy Quarks and Onia * Update on b → sγ and b → sl+l- from CLEO * Theoretical Status of B → Xsγ Decays * b - Quark Fragmentation Measurements * Leptoproduction of J/ψ * New Results on Heavy Qbar{Q} Pair Production Close to Threshold * Properties of b-Quark Production at the Tevatron * First Observation of Open b Production at HERA * Top Quark Mass from CDF * Direct Measurement of the Top Quark Mass at DØ * Gluon Radiation in Top Mass Reconstruction: Effect of Hadronic W Decays * DØ All-Hadronic Top Decay and Top Cross Section Summary * Top Quark Production and Decay Measurements from CDF * Charge Asymmetry of Heavy Quarks at Hadron Colliders * Pa-08 Heavy Hadrons: Lifetimes: Mixing, Rare Decays * B+, B0d and b-Baryon Lifetimes * Measurements of the Bs Lifetime and Search for a Lifetime Difference frac{{ΔΓ}}{Γ } * Status of D^0 - bar{D}^0 Mixing and Doubly Cabibbo-Suppressed D0 Decay Rate Measurements * Nearby Resonances and D^0 - bar{D}^0 Mixing * Oscillations of the B0d Mesons * B0s Mixing, Limits on Δms * Semileptonic B Decays at the Z0 * Selected Results on b → cℓv from CLEO * Experimental Review on |Vub| * New Measurements of |Vub| and |Vcb| with DELPHI at LEP * A Constituent Quark-Meson Model for Heavy Meson Decays * Towards the Extraction of the CKM Angle γ * Observation of the Bc Meson at CDF * Rare Hadronic B Decays * Charmless and Double-Charm B Decays at SLD * Towards a Theory of Charmless Non-Leptonic Two-Body B Decays * Nonfactorizable Effects in Charmless B Decays and B Meson Lifetimes * B/bar{B} Flavour Tagging and Doubly Charmed B Decays in ALEPH * Production of Orbitally Excited B Mesons in Z Decays * Measurement of b-baryon Polarization in Z0 Decays * Pa-09 Light Hadron Spectroscopy (Glueballs, Exotics, States with c Quarks) * Study of D** and D*' Production in B and C Jets, with the DELPHI Detector * Recent Preliminary
Proceedings of the 28th International Conference on High Energy Physics (in 2 Volumes)
Ajduk, Z.; Wroblewski, A. K.
1997-04-01
* New Experimental Techniques and Detectors * Pl-19 Future Accelerators * Future Colliders * Pl-20 Summary and Outlook * Summary and Outlook * PARALLEL SESSIONS * Pa-01 Hadron Spectroscopy * Glue Ball and Light Quark Spectroscopy * Observation of the Lightest Scalar Glueball * Determining the Gluonic Content of Isoscalar Mesons * Recent GAMS Results on the π0π0-System Produced in 38 GeV/c π-p Charge Exchange Reaction * Koverline K and 4π0 Decays of the f0 (1500) * Search for Exotic Mesons in Multiparticle Final States * Search for Exotic Baryons in the Proton Reactions * A Partial Wave Analysis of the Reaction γγ → π+ π- π0 at ARGUS * Exclusive States in γγ Collisions in L3 * Charm and Bottom Quark Spectroscopy * An Evidence for Λc(2593)+ Production at ARGUS * Observation of Σc0 Charmed Baryon in the Experiment EXCHARM * New Results on Study of ξ(2230) at BES * Recent Ψ' and Xc Results from BES * D_J^{(*)0} and D_{s1}^+(2356) Production in Hadronic Z0 Decays * Production of Orbitally Excited D Mesons in ALEPH * Observation of the D_J^{(*)0} * Strange and Bottom Quark Spectroscopy * Recent Results from the CMD-2 Detector at VEPP-2M Collider * Search for the Bc Meson in Hadronic Z Decays by ALEPH, DELPHI and L3, and Resonant Structure and Flavour Tagging in the Bπ± System by ALEPH * Evidence for Radially Excited B Mesons and the Decay B* → Be+e- * Fully Reconstructed B Decay Results from CDF * Heavy Quarkonia Mass Splittings in QCD: Test of the 1/m-Expansion and Estimates of and αs * Perturbative Corrections to the Heavy Baryons QCD Sum Rules * Pa-02 Soft Interactions and Diffraction * Soft Physics at e+ e- Colliders * Λoverline{Λ} Production in Two-Photon Interactions at CLEO * Hadron Production in γγ Collisions at √ s = 130 - 140 GeV * Particle Correlations in the DELPHI Detector at LEP * A Simple Approach to Describe Hadron Production Rates in e+e- Annihilation * Scaling in Multiplicity Distribution and the Leading Particle Effect