Unified model of current-hadronic interactions. II
International Nuclear Information System (INIS)
Moffat, J.W.; Wright, A.C.D.
1975-01-01
An analytic model of current-hadronic interactions is used to make predictions which are compared with recent data for vector-meson electroproduction and for the spin density matrix of photoproduced rho 0 mesons. The rho 0 and ω electroproduction cross sections are predicted to behave differently as the mass of the virtual photon varies; the diffraction peak broadens with increasing -q 2 at fixed ν and narrows with increasing energy. The predicted rho 0 density matrix elements do not possess the approximate s-channel helicity conservation seen experimentally. The model is continued to the inclusive electron-positron annihilation region, where parameter-free predictions are given for the inclusive prosess e + + e - → p + hadrons. The annihilation structure functions are found to have nontrivial scale-invariance limits. By using total cross-section data for e + e - annihilation into hardrons, we predict the mean multiplicity for the production of nucleons
Fermion: field nontopological solitons. II. Models for hadrons
International Nuclear Information System (INIS)
Friedberg, R.; Lee, T.D.
1977-01-01
The possibility, and its consequences, are examined that in a relativistic local field theory, consisting of color quarks q, scalar gluon sigma, color gauge field V/sub mu/ and color Higgs field phi, the mass of the soliton solution may be much lower than any mass of the plane wave solutions; i.e., m/sub q/ the quark mass, m/sub sigma/ the gluon mass, etc. There appears a rather clean separation between the physics of these low mass solitons and that of the high energy excitations, in the range of m/sub q/ and m/sub sigma/, provided that the parameters xi identical with (μ/m/sub q/) 2 and eta identical with μ/m/sub sigma/ are both much less than 1, where μ is an overall low energy scale appropriate for the solitons (but the ratio eta/xi is assumed to be O(1), though otherwise arbitrary). Under very general assumptions, it is shown that independently of the number of parameters in the original Lagrangian, the mathematical problem of finding the quasiclassical soliton solutions reduces, through scaling, to that of a simple set of two coupled first-order differential equations, neither of which contains any explicit free parameters. The general properties and the numerical solutions of this reduced set of differential equations are given. The resulting solitons exhibit physical characteristics very similar to those of a ''gas bubble'' immersed in a ''medium'': there is a constant surface tension and a constant pressure exerted by the medium on the gas; in addition, there are the ''thermodynamical'' energy of the gas and the related gas pressure, which are determined by the solutions of the reduced equations. Both a SLAC-like bag and the Creutz-Soh version of the MIT bag may appear, but only as special limiting cases. These soliton solutions are applied to the physical hadrons; their static properties are calculated and, within a 10 to 15 percent accuracy, agree with observations
International Nuclear Information System (INIS)
Greenberg, O.W.; Nelson, C.A.
1977-01-01
The evidence for a three-valued 'color' degree of freedom in hadron physics is reviewed. The structure of color models is discussed. Consequences of color models for elementary particle physics are discussed, including saturation properties of hadronic states, π 0 →2γ and related decays, leptoproduction, and lepton pair annihilation. Signatures are given which distinguish theories with isolated colored particles from those in which color is permanently bound. (Auth.)
International Nuclear Information System (INIS)
Ogava, S.; Savada, S.; Nakagava, M.
1983-01-01
Composite models of hadrons are considered. The main attention is paid to the Sakata, S model. In the framework of the model it is presupposed that proton, neutron and Λ particle are the fundamental particles. Theoretical studies of unknown fundamental constituents of a substance have led to the creation of the quark model. In the framework of the quark model using the theory of SU(6)-symmetry the classification of mesons and baryons is considered. Using the quark model relations between hadron masses, their spins and electromagnetic properties are explained. The problem of three-colour model with many flavours is briefly presented
Firetube model and hadron-hadron collisions
International Nuclear Information System (INIS)
Nazareth, R.A.M.S.; Kodama, T.; Portes Junior, D.A.
1992-01-01
A new version of the fire tube model is developed to describe hadron-hadron collisions at ultrarelativistic energies. Several improvements are introduced in order to include the longitudinal expansion of intermediate fireballs, which remedies the overestimates of the transverse momenta in the previous version. It is found that, within a wide range of incident energies, the model describes well the experimental data for the single particle rapidity distribution, two-body correlations in the pseudo-rapidity, transverse momentum spectra of pions and kaons, the leading particle spectra and the K/π ratio. (author)
Quark models in hadron physics
International Nuclear Information System (INIS)
Phatak, Shashikant C.
2007-01-01
In this talk, we review the role played by the quark models in the study of interaction of strong, weak and electromagnetic probes with hadrons at intermediate and high momentum transfers. By hadrons, we mean individual nucleons as well as nuclei. We argue that at these momentum transfers, the structure of hadrons plays an important role. The hadron structure of the hadrons is because of the underlying quark structure of hadrons and therefore the quark models play an important role in determining the hadron structure. Further, the properties of hadrons are likely to change when these are placed in nuclear medium and this change should arise from the underlying quark structure. We shall consider some quark models to look into these aspects. (author)
Statistical hadronization and hadronic micro-canonical ensemble II
International Nuclear Information System (INIS)
Becattini, F.; Ferroni, L.
2004-01-01
We present a Monte Carlo calculation of the micro-canonical ensemble of the ideal hadron-resonance gas including all known states up to a mass of about 1.8 GeV and full quantum statistics. The micro-canonical average multiplicities of the various hadron species are found to converge to the canonical ones for moderately low values of the total energy, around 8 GeV, thus bearing out previous analyses of hadronic multiplicities in the canonical ensemble. The main numerical computing method is an importance sampling Monte Carlo algorithm using the product of Poisson distributions to generate multi-hadronic channels. It is shown that the use of this multi-Poisson distribution allows for an efficient and fast computation of averages, which can be further improved in the limit of very large clusters. We have also studied the fitness of a previously proposed computing method, based on the Metropolis Monte Carlo algorithm, for event generation in the statistical hadronization model. We find that the use of the multi-Poisson distribution as proposal matrix dramatically improves the computation performance. However, due to the correlation of subsequent samples, this method proves to be generally less robust and effective than the importance sampling method. (orig.)
Quark-model study of the hadron structure and the hadron-hadron interaction
International Nuclear Information System (INIS)
Valcarce, A; Caramés, T F; Vijande, J; Garcilazo, H
2011-01-01
Recent results of hadron spectroscopy and hadron-hadron interaction within a quark model framework are reviewed. Higher order Fock space components are considered based on new experimental data on low-energy hadron phenomenology. The purpose of this study is to obtain a coherent description of the low-energy hadron phenomenology to constrain QCD phenomenological models and try to learn about low-energy realizations of the theory.
Exotic hadron and string junction model
International Nuclear Information System (INIS)
Imachi, Masahiro
1978-01-01
Hadron structure is investigated adopting string junction model as a realization of confinement. Besides exotic hadrons (M 4 , B 5 etc.), unconventional hadrons appear. A mass formula for these hadrons is proposed. New selection rule is introduced which requires the covalence of constituent line at hadron vertex. New duality appears due to the freedom of junction, especially in anti BB→anti BB reaction. A possible assignment of exotic and unconventional hadrons to recently observed narrow meson states is presented. (auth.)
International Nuclear Information System (INIS)
DeTar, C.E.; Donoghue, J.F.
1983-01-01
We believe further progress in the bag model must come from a better understanding of QCD. The bag theory is basically a simple model of the vacuum. A ''perturbative'' vacuum of finite extent is found inside the bag, while the ''true'' vacuum is found outside. The formation of the bag can be viewed as a phase change between the two types of vacuum. In what sense does QCD support this view. There have been many recent attempts to characterize the QCD vacuum. Of particular relevance to the bag model is recent work by Hansson et al. They set out to determine the structure of the vacuum wave function by using a variational argument. Their ''trial'' wave function was inspired by the bag model, but their intention was to describe general features of QCD. Their work starts from the realization that with the usual perturbative model of the vacuum a J /sup PC/ = 0 ++ glueball state can be made with m 2 ++ glueball (C. B. Thorn, unpublished), which leads to a state with m 2 < 0 when c.m. corrections are included (65). Hansson et al show that the perturbative vacuum can lower its energy by filling up with scalar glueballs. They calculate the energy of glueballs containing two and four gluons and find that the energy of the four-gluon state is higher. Therefore the vacuum energy reaches a minimum when the glueballs start to overlap
Model Hadron asymptotic behaviour
International Nuclear Information System (INIS)
Kralchevsky, P.; Nikolov, A.
1983-01-01
The work is devoted to the problem of solving a set of asymptotic equations describing the model hardon interaction. More specifically an interactive procedure consisting of two stages is proposed and the first stage is exhaustively studied here. The principle of contracting transformations has been applied for this purpose. Under rather general and natural assumptions, solutions in a series of metric spaces suitable for physical applications have been found. For each of these spaces a solution with unique definiteness is found. (authors)
Heavy hadron spectroscopy: A quark model perspective
International Nuclear Information System (INIS)
Vijande, J.; Valcarce, A.; Caramés, T.F.; Garcilazo, H.
2013-01-01
We present recent results of hadron spectroscopy and hadron–hadron interaction from the perspective of constituent quark models. We pay special attention to the role played by higher order Fock space components in the hadron spectra and the connection of this extension with the hadron–hadron interaction. The main goal of our description is to obtain a coherent understanding of the low-energy hadron phenomenology without enforcing any particular model, to constrain its characteristics and learn about low-energy realization of the theory
International Nuclear Information System (INIS)
Migdal, A.B.; Khokhlachev, S.B.; Borue, V.Yu.
1989-01-01
The hadron is considered as a stringlike gluon drop with a quark and antiquark near the ends of the 'string' for a meson and with the antiquark replaced by a diquark for a baryon. The softer 'string' modes are the rotations and the longitudinal vibrations. Quantization of these modes enables to describe the hadron spectra. (orig.)
Collective vs atomic models of the hadrons
International Nuclear Information System (INIS)
Stokar, S.
1983-02-01
We examine the relationship between heavy and light quark systems. Using a Bogoliubov-Valatin transformation we show how to interpolate continuously between heavy quark atomic models and light quark collective models of the hadrons. (author)
A High Intensity Hadron Facility, AGS II
International Nuclear Information System (INIS)
Lee, Y.Y.; Lowenstein, D.I.
1988-01-01
We have present one of several possibilities for the evolution of the AGS complex into a high intensity hadron facility. One could consider other alternatives, such as using the AGS as the Collector and constructing a new 9-30 GeV machine. We believe the most responsible scenario must minimize the cost and downtime to the ongoing physics program. With a stepwise approach, starting with the Booster, the physics program can evolve without a single major commitment in funds. At each step an evaluation of the funds versus physics merit can be made. As a final aside, each upgrade at the AGS and Booster is presently being implemented to support an interleaved operation of both protons and ions. 1 fig., 6 tabs
Phase transition in the hadron gas model
International Nuclear Information System (INIS)
Gorenstein, M.I.; Petrov, V.K.; Zinov'ev, G.M.
1981-01-01
A class of statistical models of hadron gas allowing an analytical solution is considered. A mechanism of a possible phase transition in such a system is found and conditions for its occurence are determined [ru
Modelling hadronic interactions in HEP MC generators
Skands, Peter
2015-01-01
HEP event generators aim to describe high-energy collisions in full exclusive detail. They combine perturbative matrix elements and parton showers with dynamical models of less well-understood phenomena such as hadronization, diffraction, and the so-called underlying event. We briefly summarise some of the main concepts relevant to the modelling of soft/inclusive hadron interactions in MC generators, in particular PYTHIA, with emphasis on questions recently highlighted by LHC data.
Strange Hadronic Matter in a Chiral Model
Institute of Scientific and Technical Information of China (English)
ZHANG Li-Liang; SONG Hong-Qiu; WANG Ping; SU Ru-Keng
2000-01-01
The strange hadronic matter with nucleon, Λ-hyperon and E-hyperon is studied by using a chiral symmetry model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed. The result indicates a quite large strangeness fraction (fs) region where the strange hadronic matter is stable against particle emission. In the large fs region, the component dominates, resulting in a deep minimum in the curve of the binding energy per baryon EB versus the strangeness fraction fs with (EB, fs) -～ (-26.0MeV, 1.23).
Hadron interactions in quark models
International Nuclear Information System (INIS)
Narodetskij, I.M.
1987-01-01
Some recent developments on the study of quark degrees of freedom in hadron scattering at intermediate energy are reviewed. Physical foundations of the P-matrix approach and the Quark Compound Bag method are discussed including applications to pion-pion, pion-nucleon, nucleon-nucleon and three-nucleon systems
Model for nucleus-nucleus, hadron-nucleus and hadron-proton multiplicity distributions
International Nuclear Information System (INIS)
Singh, C.P.; Shyam, M.; Tuli, S.K.
1986-07-01
A model relating hadron-proton, hadron-nucleus and nucleus-nucleus multiplicity distributions is proposed and some interesting consequences are derived. The values of the parameters are the same for all the processes and are given by the QCD hypothesis of ''universal'' hadronic multiplicities which are found to be asymptotically independent of target and beam in hadronic and current induced reactions in particle physics. (author)
A rotating bag model for hadrons. 2
International Nuclear Information System (INIS)
Iwasaki, Masaharu
1994-01-01
The MIT bag model is modified in order to describe rotational motion of hadrons. It has a kind of 'diatomic molecular' structure; The rotational excitation of the MIT bag is described by the polarized two colored sub-bags which are connected with each other by the gluon flux. One sub-bag contains a quark and the other has an antiquark for mesons. For baryons, the latter sub-bag contains the remaining two quarks instead of the antiquark. The Regge trajectories of hadrons are explained qualitatively by our new model with the usual MIT bag parameters. In particular the Regge slopes are reproduced fairly well. It is also pointed out that the gluon flux plays an important role in the rotational motion of hadrons. (author)
Improved modelling of independent parton hadronization
International Nuclear Information System (INIS)
Biddulph, P.; Thompson, G.
1989-01-01
A modification is proposed to current versions of the Field-Feynman ansatz for the hadronization of a quark in Monte Carlo models of QCD interactions. This faster-running algorithm has no more parameters and imposes a better degree of energy conservation. It results in naturally introducing a limitation of the transverse momentum distribution, similar to the experimentally observed ''seagull'' effect. There is now a much improved conservation of quantum numbers between the original parton and resultant hadrons, and the momentum of the emitted parton is better preserved in the summed momentum vectors of the final state particles. (orig.)
Hadron structure in the ladder model
International Nuclear Information System (INIS)
Soper, D.E.
1979-01-01
The (flavor non-singlet) Green's function to find a far-off-shell quark in a hadron is obtained in the renormalization group improved ladder model for QCD in the space-like axial gauge. Particular attention is paid to the role of the singularity in the gluon propagator. 4 figures
International Nuclear Information System (INIS)
Moehring, H.; Ranft, J.; Capella, A.; Tran Thanh Van, J.
1993-01-01
Λ, bar Λ, and K S 0 production is studied in a Monte Carlo dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions with an SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation process. Additionally, (qq)-(bar q bar q) production from the sea was introduced into the chain formation process with the same probability as for the q→qq branching within the chain decay process. With these assumptions, multiplicity ratios and Feynman-x distributions for strange particles in h-h and multiplicity ratios in heavy ion collisions are reasonably well reproduced
Hadronic mass-relations from topological expansion and string model
International Nuclear Information System (INIS)
Kaidalov, A.B.
1980-01-01
Hadronic mass-relations from topological expansion and string model are derived. For this purpose the space- time picture of hadron interactions at high energies corresponding to planar diagrams of topological expansion is considered. Simple relations between intercepts and slopes of Regge trajectories based on the topological expansion and q anti q-string picture of hadrons are obtained [ru
Effective potential models for hadrons
International Nuclear Information System (INIS)
Lucha, W.
1995-12-01
The aim of these lectures is to give a self-contained introduction to nonrelativistic potential models, to their formulation as well as to their possible applications. At the price of some lack of (in a mathematical sense) rigorous derivations, we try to give a feeling and understanding for the simplest conceivable method to extract the explicit form of the forces acting between quarks from the interplay between experimental observations and theoretical considerations. According to this spirit, we demonstrate, in detail, how to obtain the underlying Hamiltonian and how to determine the Lorentz structure of the quark-(anti-)quark interaction potential from well-established experimental facts. (author)
Second quantization approach to composite hadron interactions in quark models
International Nuclear Information System (INIS)
Hadjimichef, D.; Krein, G.; Veiga, J.S. da; Szpigel, S.
1995-11-01
Starting from the Fock space representation of hadron bound states in a quark model, a change of representation is implemented by a unitary transformation such that the composite hadrons are redescribed by elementary-particle field operators. Application of the unitary transformation to the microscopic quark Hamiltonian gives rise to effective hadron-hadron, hadron-quark, and quark-quark Hamiltonians. An effective baryon Hamiltonian is derived using a simple quark model. The baryon Hamiltonian is free of the post-prior discrepancy which usually plagues composite-particle effective interactions. (author). 13 refs., 1 fig
The hadronic standard model for strong and electroweak interactions
International Nuclear Information System (INIS)
Raczka, R.
1993-01-01
We propose a new model for strong and electro-weak interactions. First, we review various QCD predictions for hadron-hadron and lepton-hadron processes. We indicate that the present formulation of strong interactions in the frame work of Quantum Chromodynamics encounters serious conceptual and numerical difficulties in a reliable description of hadron-hadron and lepton-hadron interactions. Next we propose to replace the strong sector of Standard Model based on unobserved quarks and gluons by the strong sector based on the set of the observed baryons and mesons determined by the spontaneously broken SU(6) gauge field theory model. We analyse various properties of this model such as asymptotic freedom, Reggeization of gauge bosons and fundamental fermions, baryon-baryon and meson-baryon high energy scattering, generation of Λ-polarization in inclusive processes and others. Finally we extend this model by electro-weak sector. We demonstrate a remarkable lepton and hadron anomaly cancellation and we analyse a series of important lepton-hadron and hadron-hadron processes such as e + + e - → hadrons, e + + e - → W + + W - , e + + e - → p + anti-p, e + p → e + p and p + anti-p → p + anti-p processes. We obtained a series of interesting new predictions in this model especially for processes with polarized particles. We estimated the value of the strong coupling constant α(M z ) and we predicted the top baryon mass M Λ t ≅ 240 GeV. Since in our model the proton, neutron, Λ-particles, vector mesons like ρ, ω, φ, J/ψ ect. and leptons are elementary most of experimentally analysed lepton-hadron and hadron-hadron processes in LEP1, LEP2, LEAR, HERA, HERMES, LHC and SSC experiments may be relatively easily analysed in our model. (author). 252 refs, 65 figs, 1 tab
Energy Technology Data Exchange (ETDEWEB)
Bertoli, Gabriele [Univ. of Trieste (Italy)
2015-08-27
We present the results of the CDF search for a Standard Model Higgs boson decaying into a pair of W bosons with electrons, muons and hadronically decaying taus in the final state. In particular, we investigate a channel with three objects, two leptons and a tau. In 9.7 fb^{-1} of data we expect 40.0 ± 5.4 background events and 0.54 ± 0.05 signal events for a Higgs mass hypothesis of 160 GeV/c^{2}, whereas in data we count 28 events. We set a 95% C.L. upper limit on σ/σSM of 12.6 for a Higgs mass hypothesis of 160 GeV/c^{2}. The expected 95% C.L. upper limit for the same mass is 12.4. Results for other ninete 0 GeV/c2 to 200 GeV/c^{2} are also presented.
A deformable bag model of hadrons, 1
International Nuclear Information System (INIS)
Ui, Haruo; Saito, Koich
1983-01-01
As a generalization of the MIT spherical bag model, we construct the spheroidal bag model of hadron with an arbitrary eccentricity. This generalization is made by slightly modifying the MIT linear boundary condition: The linear boundary condition is examined in detail. Our model always satisfies two necessary requirements of the MIT bag model - i.e., n.j = 0, no quark colour flux leaves the bag, and q-barq = 0, the scalar density of quark should vanish on the bag surface- and it reduces to the MIT spherical bag model in the limit of zero-eccentricity. Lagrangian formalism of our model is briefly described. The eigenfrequencies of a single massless quark confined in this spheroidal bag are numerically calculated. We obtain the level-splitting of the excited quark orbits, which is just analogous to the well-known Nilsson's splitting of single particle orbits in deformed nuclei. By using the numerical results of the lowest orbit, the effect of the bag-deformation on the mass of low-lying hadrons is estimated. It is found that, although the spherical bag is stable, the quark bag is extremely soft against the quadrupole deformation. Brief discussions are added on the mechanisms which make the spherical bag more stable. (author)
Quantum chromodynamic quark model study of hadron and few hadron systems
International Nuclear Information System (INIS)
Ji, Chueng-Ryong.
1990-10-01
This report details research progress and results obtained during the five month period July 1, 1990 to November 30, 1990. The research project, entitled ''Quantum Chromodynamic Quark Model Study of Hadron and Few Hadron Systems,'' is supported by grant FG05-90ER40589 between North Carolina State University and the United States Department of Energy. This is a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. The new, significant research results are briefly summarized in the following sections
Hadron properties in chiral sigma model
International Nuclear Information System (INIS)
Shen Hong
2005-01-01
The modification of hadron masses in nuclear medium is studied by using the chiral sigma model, which is extended to generate the omega meson mass by the sigma condensation in the vacuum in the same way as the nucleon mass. The chiral sigma model provides proper equilibrium properties of nuclear matter. It is shown that the effective masses of both nucleons and omega mesons decrease in nuclear medium, while the effective mass of sigma mesons increases oat finite density in the chiral sigma model. The results obtained in the chiral sigma model are compared with those obtained in the Walecka model, which includes sigma and omega mesons in a non-chiral fashion. (author)
Relativistic direct interaction and hadron models
International Nuclear Information System (INIS)
Biswas, T.
1984-01-01
Direct interaction theories at a nonrelativistic level have been used successfully in several areas earlier (e.g. nuclear physics). But for hadron spectroscopy relativistic effects are important and hence the need for a relativistic direct interaction theory arises. It is the goal of this thesis to suggest such a theory which has the simplicity and the flexibility required for phenomenological model building. In general the introduction of relativity in a direct interaction theory is shown to be non-trivial. A first attempt leads to only an approximate form for allowed interactions. Even this is far too complex for phenomenological applicability. To simplify the model an extra spacelike particle called the vertex is introduced in any set of physical (timelike) particles. The vertex model is successfully used to fit and to predict experimental data on hadron spectra, γ and psi states fit very well with an interaction function inspired by QCD. Light mesons also fit reasonably well. Better forms of hyperfine interaction functions would be needed to improve the fitting of light mesons. The unexpectedly low pi meson mass is partially explained. Baryon ground states are fitted with unprecedented accuracy with very few adjustable parameters. For baryon excited states it is shown that better QCD motivated interaction functions are needed for a fit. Predictions for bb states in e + e - experiments are made to assist current experiments
International Nuclear Information System (INIS)
Altsybeev, Igor
2016-01-01
In the present work, Monte-Carlo toy model with repulsing quark-gluon strings in hadron-hadron collisions is described. String repulsion creates transverse boosts for the string decay products, giving modifications of observables. As an example, long-range correlations between mean transverse momenta of particles in two observation windows are studied in MC toy simulation of the heavy-ion collisions
The QCD model of hadron cores of the meson theory
International Nuclear Information System (INIS)
Pokrovskii, Y.E.
1985-01-01
It was shown that in the previously proposed QCD model of hadron cores the exchange and self-energy contributions of the virtual quark-antiquark-gluon cloud on the outside of a bag which radius coincides with the hardon core radius of the meson theory (∼ 0.4 Fm) have been taken into account at the phenomenological level. Simulation of this cloud by the meson field results in realistic estimations of the nucleon's electroweak properties, moment fractions carried by gluons, quarks, antiquarks and hadron-hadron interaction cross-sections within a wide range of energies. The authors note that the QCD hadron core model proposed earlier not only realistically reflects the hadron masses, but reflects self-consistently main elements of the structure and interaction of hadrons at the quark-gluon bag radius (R - 0.4Fm) being close to the meson theory core radius
Quark approach to Santilli's conjecture on hadronic structure - II
International Nuclear Information System (INIS)
Animalu, A.O.E.
1982-08-01
In this paper, we continue an earlier investigation of an exactly soluble relativistic Bohr-type model of the internal structure of the proton (three-quark baryon system) and the pion (quark-antiquark meson system), based on a realization of Santilli's conjecture that the hadronic constituents are extended (non-pointlike) objects. The model is abstracted from an expansion of a Yukawa-type potential between the valence quarks and a massive core, in which the meson or gluon exchange term has the effect of reducing the effective Bohr radius for binding to a value less than the radius of the strong charge sphere (or Compton wavelength) of each constituent, so that appreciable overlap of charge volumes occurs, to within a typical distance of order 0.25F or 1/(800 MeV) in qqq-system, and order 1/(1200 MeV) in qq-bar-system, which are comparable to gluon masses, msub(G) approx.= 800 to 1200 MeV, required by the lattice QCD and the MIT Bag Model. Based on the assumptions that the ground state of the proton has 1s 2 2s valence quark configuration, the non-strange quark mass is msub(p)/3, and the dimensionless strong coupling constant of the Yukawa-type potential is g 2 =1, the mass of the proton core is determined self-consistently to be 2470 MeV, exactly balancing the quark binding energy so that the valence quarks appear free. The model correctly predicts the masses of the well-known resonant states of the proton with Jsup(P)=1/2 + as excited states associated with the configuration 1s2s 2 and predicts an upper bound (spectroscopic limit) for the mass of the excited states of the proton in ns 2 ms configuration, as n→infinity and m→infinity, to be 3409 MeV. Based on a generalization of the model to qq-bar-systems, an upper bound (spectroscopic limit) for the mass of qq-bar in ns 2 configuration, as n→infinity, is found to be 3096 MeV, which is the mass of the J/psi-meson. The relation of the model to violation of time-reversal invariance (T-symmetry) by non
Test of a chromomagnetic model for hadron mass differences
Lichtenberg, D. B.; Roncaglia, R.
1993-05-01
An oversimplified model consisting of the QCD color-magnetic interaction has been used previously by Silvestre-Brac and others to compare the masses of exotic and normal hadrons. We show that the model can give qualitatively wrong answers when applied to systems of normal hadrons.
Test of a chromomagnetic model for hadron mass differences
International Nuclear Information System (INIS)
Lichtenberg, D.B.; Roncaglia, R.
1993-01-01
An oversimplified model consisting of the QCD color-magnetic interaction has been used previously by Silvestre-Brac and others to compare the masses of exotic and normal hadrons. We show that the model can give qualitatively wrong answers when applied to systems of normal hadrons
Nonscaling parametrization of hadronic spectra and dual parton model
International Nuclear Information System (INIS)
Gaponenko, O.N.
2001-01-01
Using the popular Wdowczyk-Wolfendale parametrization (WW-parametrization) as an example one studies restrictions imposed by a dual parton model for different nonscaling parametrizations of the pulsed hadron spectra in soft hadron-hadron and hadron-nuclear interactions. One derived a new parametrization free from basic drawback of the WW-formulae. In the central range the determined parametrization show agreement with the Wdowczyk-Wolfendale formula, but in contrast to the last-named one it does not result in contradiction with the experiment due to fast reduction of inelastic factor reduction with energy increase [ru
Geometric branching model of high-energy hadron-hadron collisions
International Nuclear Information System (INIS)
Chen, W.
1988-01-01
A phenomenological model is proposed to describe collisions between hadrons at high energies. In the context of the eikonal formalism, the model consists of two components: soft and hard. The former only involves the production of particles with small transverse momenta; the latter is characterized by jet production. Geometrical scaling is taken as an essential input to describe the geometrical properties of hadrons as extended objects on the one hand, and on the other to define the soft component in both regions below and above the jet threshold. A stochastical Furry branching process is adopted as the mechanism of soft particle production, while the jet fragmentation and gluon initial-state bremsstrahlung are for the production of hadrons in hard collisions. Impact parameter and virtuality are smeared to describe the statistical averaging effects of hadron-hadron collisions. Many otherwise separated issues, ranging from elastic scattering to parton decay function, are connected together in the framework of this model. The descriptions of many prominent features of hadronic collisions are in good agreement with the observed experimental data at all available energies. Multiplicity distributions at all energies are discussed as a major issue in this paper. KNO scaling is achieved for energies within ISR range. The emergence of jets is found to be responsible not only for the violation of both geometrical scaling and KNO scaling, but also for the continuous broadening of the multiplicity distribution with ever increasing energy. It is also shown that the geometrical size of a hadron reaches an asymptote in the energy region of CERN-SppS. A Monte Carlo version of the model for soft production is constructed
On Some Novel Ideas in Hadron Physics. Part II
Directory of Open Access Journals (Sweden)
Christianto V.
2010-04-01
Full Text Available As a continuation of the preceding section, we shortly review a series of novel ideas on the physics of hadrons. In the present paper, emphasis is given on some different approaches to the hadron physics, which may be called as “programs” in the sense of Lakatos. For clarity, we only discuss geometrization program, symmetries / unification program, and phenomenology of inter-quark potential program.
On Some Novel Ideas in Hadron Physics. Part II
Directory of Open Access Journals (Sweden)
Smarandache F.
2010-04-01
Full Text Available As a continuation of the preceding section, we shortly review a series of novel ideas on the physics of hadrons. In the present paper, emphasis is given on some different approaches to the hadron physics, which may be called as "programs" in the sense of Lakatos. For clarity, we only discuss geometrization program, symmetries/unification program, and phenomenology of inter-quark potential program.
The hadronic standard model for strong and electroweak interactions
Energy Technology Data Exchange (ETDEWEB)
Raczka, R. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)
1993-12-31
We propose a new model for strong and electro-weak interactions. First, we review various QCD predictions for hadron-hadron and lepton-hadron processes. We indicate that the present formulation of strong interactions in the frame work of Quantum Chromodynamics encounters serious conceptual and numerical difficulties in a reliable description of hadron-hadron and lepton-hadron interactions. Next we propose to replace the strong sector of Standard Model based on unobserved quarks and gluons by the strong sector based on the set of the observed baryons and mesons determined by the spontaneously broken SU(6) gauge field theory model. We analyse various properties of this model such as asymptotic freedom, Reggeization of gauge bosons and fundamental fermions, baryon-baryon and meson-baryon high energy scattering, generation of {Lambda}-polarization in inclusive processes and others. Finally we extend this model by electro-weak sector. We demonstrate a remarkable lepton and hadron anomaly cancellation and we analyse a series of important lepton-hadron and hadron-hadron processes such as e{sup +} + e{sup -} {yields} hadrons, e{sup +} + e{sup -} {yields} W{sup +} + W{sup -}, e{sup +} + e{sup -} {yields} p + anti-p, e + p {yields} e + p and p + anti-p {yields} p + anti-p processes. We obtained a series of interesting new predictions in this model especially for processes with polarized particles. We estimated the value of the strong coupling constant {alpha}(M{sub z}) and we predicted the top baryon mass M{sub {Lambda}{sub t}} {approx_equal} 240 GeV. Since in our model the proton, neutron, {Lambda}-particles, vector mesons like {rho}, {omega}, {phi}, J/{psi} ect. and leptons are elementary most of experimentally analysed lepton-hadron and hadron-hadron processes in LEP1, LEP2, LEAR, HERA, HERMES, LHC and SSC experiments may be relatively easily analysed in our model. (author). 252 refs, 65 figs, 1 tab.
The hadronic standard model for strong and electroweak interactions
Energy Technology Data Exchange (ETDEWEB)
Raczka, R [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)
1994-12-31
We propose a new model for strong and electro-weak interactions. First, we review various QCD predictions for hadron-hadron and lepton-hadron processes. We indicate that the present formulation of strong interactions in the frame work of Quantum Chromodynamics encounters serious conceptual and numerical difficulties in a reliable description of hadron-hadron and lepton-hadron interactions. Next we propose to replace the strong sector of Standard Model based on unobserved quarks and gluons by the strong sector based on the set of the observed baryons and mesons determined by the spontaneously broken SU(6) gauge field theory model. We analyse various properties of this model such as asymptotic freedom, Reggeization of gauge bosons and fundamental fermions, baryon-baryon and meson-baryon high energy scattering, generation of {Lambda}-polarization in inclusive processes and others. Finally we extend this model by electro-weak sector. We demonstrate a remarkable lepton and hadron anomaly cancellation and we analyse a series of important lepton-hadron and hadron-hadron processes such as e{sup +} + e{sup -} {yields} hadrons, e{sup +} + e{sup -} {yields} W{sup +} + W{sup -}, e{sup +} + e{sup -} {yields} p + anti-p, e + p {yields} e + p and p + anti-p {yields} p + anti-p processes. We obtained a series of interesting new predictions in this model especially for processes with polarized particles. We estimated the value of the strong coupling constant {alpha}(M{sub z}) and we predicted the top baryon mass M{sub {Lambda}{sub t}} {approx_equal} 240 GeV. Since in our model the proton, neutron, {Lambda}-particles, vector mesons like {rho}, {omega}, {phi}, J/{psi} ect. and leptons are elementary most of experimentally analysed lepton-hadron and hadron-hadron processes in LEP1, LEP2, LEAR, HERA, HERMES, LHC and SSC experiments may be relatively easily analysed in our model. (author). 252 refs, 65 figs, 1 tab.
Volterra model and quark hadronization into multicomponent hadron system
International Nuclear Information System (INIS)
Darbaidze, Ya.Z.; Rostovtsev, V.A.
1989-01-01
The examples of the multiparticle process characteristic dependence on the number of a low correlated components are considered. The possibility for reducing the differential equation system, which was obtained earlier, to a dissipative type Volterra model of competing biological species for the same food is discussed. An algorithm for the analytical computation of the high order differential equation as a resultant of the of the arising system is given. The examples of linearization and solution of these equations describing the associated multiplicities of charge particles are represented. 25 refs.; 1 tab
Hadron Azimuthal Correlations and Mach-like Structures in a Partonic/Hadronic Transport Model
International Nuclear Information System (INIS)
Ma, G.L.; Zhang, S.; Ma, Y.G.; Cai, X.Z.; Chen, J.H.; He, Z.J.; Huang, H.Z.; Long, J.L.; Shen, W.Q.; Shi, X.H.; Zhong, C.; Zuo, J.X.
2007-01-01
With a multi-phase transport model (AMPT) with both partonic and hadronic interactions, two- and three-particle azimuthal correlations in Au + Au collisions at s NN =200 GeV have been studied by the mixing-event technique. A Mach-like structure has been observed in two- and three-particle correlations in central collisions. It has been found that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure. However, only hadronic rescattering is unable to reproduce experimental amplitude of Mach-like structure, and parton cascade process is indispensable. The results of three-particle correlation indicate a partonic Mach-like shock wave can be produced by strong parton cascade in central Au+Au collisions
Composite models of hadrons and relativistic bound states
International Nuclear Information System (INIS)
Filippov, A.T.
1977-01-01
The following problems are considered: what the constituents of the hadrons are; what their quantum numbers and their broken and unbroken symmetries are; what the dynamics of the constituents (equations, binding forces and the origin of symmetry violations) is. The most puzzling question is: why the constituents ''escape from freedom'' and are confined inside the hadrons; what experimentalists can report about the hadron constituents and their dynamics if not finding them. There are no final answers to all these questions. The achievements of quark model are described, some problems concerning the comparison of the quark model with experiment are considered. The attempt is also made to present alternative views on the same problems
Exotic hadron production in a quark combination model
International Nuclear Information System (INIS)
Han Wei; Shao Fenglan; Li Shiyuan; Shang Yonghui; Yao Tao
2009-01-01
The philosophy on production of exotic hadrons (multiquark states) in the framework of the quark combination model is investigated, taking f 0 (980) as an example. The production rate and p T spectra of f 0 (980) considered as (ss) or (sqsq), respectively, are calculated and compared in Au+Au collisions at √(s NN )=200 GeV. The unitarity of various combination models, when open for exotic hadron production, is addressed.
Polyakov loop and the hadron resonance gas model.
Megías, E; Arriola, E Ruiz; Salcedo, L L
2012-10-12
The Polyakov loop has been used repeatedly as an order parameter in the deconfinement phase transition in QCD. We argue that, in the confined phase, its expectation value can be represented in terms of hadronic states, similarly to the hadron resonance gas model for the pressure. Specifically, L(T)≈1/2[∑(α)g(α)e(-Δ(α)/T), where g(α) are the degeneracies and Δ(α) are the masses of hadrons with exactly one heavy quark (the mass of the heavy quark itself being subtracted). We show that this approximate sum rule gives a fair description of available lattice data with N(f)=2+1 for temperatures in the range 150 MeVmodels. For temperatures below 150 MeV different lattice results disagree. One set of data can be described if exotic hadrons are present in the QCD spectrum while other sets do not require such states.
Model independent spin determination at hadron colliders
International Nuclear Information System (INIS)
Edelhaeuser, Lisa
2012-01-01
By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s ff of the adjacent particles. In this thesis we
Model independent spin determination at hadron colliders
Energy Technology Data Exchange (ETDEWEB)
Edelhaeuser, Lisa
2012-04-25
By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s{sub ff} of the adjacent particles. In this thesis
Model independent spin determination at hadron colliders
Energy Technology Data Exchange (ETDEWEB)
Edelhaeuser, Lisa
2012-04-25
By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s{sub ff} of the adjacent particles. In this thesis
Light hadrons in the bag model with broken chiral symmetry
International Nuclear Information System (INIS)
Efrosinin, V.P.; Zaikin, D.A.
1987-01-01
A version of the bag model with broken chiral symmetry is proposed. A satisfactory description of the experimental data on light hadrons including the pion is obtained. The estimate of the pion-nucleon σ term is given in the framework of this model. The pion and kaon decay constants are calculated. The centre-of-mass motion problem in bag models is discussed
Quantum chromodynamic quark model study of hadron and few hadron systems
International Nuclear Information System (INIS)
Ji, Chueng-Ryong.
1991-05-01
This report details research progress and results obtained during the one year period December 1, 1990 to November 30, 1991. The research project, entitled ''Quantum Chromodynamic Quark Model Study of Hadron and Few Hadron Systems,'' is supported by grant FG05-90ER40589 between North Carolina State University and the United States Department of Energy. In compliance with grant requirements the principal investigator, Professor Chueng-Ryong Ji, has conducted a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. This principal investigator has devoted 50% of his time during the academic year and 100% of his time in the summer. This percent effort will continue for the remaining period of the grant. The new, significant research results are briefly summarized in the following sections. Recent progress has been reported in the renewal/continuation grant proposal just submitted to the Department of Energy. Finally, full, detailed descriptions of completed work can be found in the project publications which are listed at the end of this progress report
International Nuclear Information System (INIS)
Friebel, W.; Kriegel, U.; Nahnhauer, R.
1979-01-01
Introducing quark transverse momenta and masses it is proposed a 3-dimensional generalization of the quark recombination and the quark fusion model for meson production in low transverse momentum hadron-hadron reactions. A consistent description of vector meson production in proton-proton and proton-antiproton reactions from 12 - 405 GeV/c has been achieved. (author)
A Toy Model for QCD: Hadrons, Penta- and Heptaquarks
International Nuclear Information System (INIS)
Nunez, M.; Hess, P.O.; Civitarese, O.; Reboiro, M.
2004-01-01
A toy model for QCD is presented and applied to the hadron spectrum. As a byproduct the structure of penta- and hepta-quarks is obtained. A complete classification of the states is given. One essential feature of the model is the non-conservation of particle number
On model-independent analyses of elastic hadron scattering
International Nuclear Information System (INIS)
Avila, R.F.; Campos, S.D.; Menon, M.J.; Montanha, J.
2007-01-01
By means of an almost model-independent parametrization for the elastic hadron-hadron amplitude, as a function of the energy and the momentum transfer, we obtain good descriptions of the physical quantities that characterize elastic proton-proton and antiproton-proton scattering (total cross section, r parameter and differential cross section). The parametrization is inferred on empirical grounds and selected according to high energy theorems and limits from axiomatic quantum field theory. Based on the predictive character of the approach we present predictions for the above physical quantities at the Brookhaven RHIC, Fermilab Tevatron and CERN LHC energies. (author)
The Mathematical Model High Energy Collisions Process Hadron-Nucleus
International Nuclear Information System (INIS)
Wojciechowski, A.; Strugalska-Gola, E.; Strugalski, Z.
2002-01-01
During the passage high energy hadron by the heavy nucleus emitted are nucleons and many other particles from which most more group are nucleons and mesons π + π - π 0 . in this work we will present the mathematical model which is a simplified description of basic processes in the interior of the nucleus during passing of the hadron by the nucleus. Result of calculations we will compare with experimental results. Experimental data are based on photographs of 180 litre xenon bubble chambers (180 1 KKP) of Institute of Theoretical and Experimental Physics in Moscow (ITEF, Moscow) irradiated with the beam of mesons π - with momentum 3.5 GeV/c. (author)
Behaviour of hadron matter within the bag model: Pt. 2
International Nuclear Information System (INIS)
Auberson, G.; Savatier, F.
1988-01-01
On the basis of the quantum theory of the vibrating bag developed in I, it is worked out the partition function of a gas of hadronic bags. This is done within the small deformation, Van der Waals approximation. The outcome is in full agreement with a previous, less elaborate model of deconfinement phase transition
Fluctuations and correlations in statistical models of hadron production
International Nuclear Information System (INIS)
Gorenstein, M. I.
2012-01-01
An extension of the standard concept of the statistical ensembles is suggested. Namely, the statistical ensembles with extensive quantities fluctuating according to an externally given distribution are introduced. Applications in the statistical models of multiple hadron production in high energy physics are discussed.
High energy hadron-hadron collisions
International Nuclear Information System (INIS)
Chou, T.T.
1990-01-01
Results of a study on high energy collision with the geometrical model are summarized in three parts: (i) the elastic hadron-hadron collision, (ii) the inelastic hadron-hadron collision, and (iii) the e + e - annihilation. The geometrical description of high-energy elastic scattering developed earlier is still in general agreement with experiments at the CERN-S bar ppS energies. A simple one-parameter expression for the blackness of bar pp system has been proposed recently which describes very well all existing data from ISR to S bar ppS energies. The geometrical description has also been extended to include processes of fragmentation and diffraction dissociation and other phenomena. In the past five years, a unified physical picture for multiparticle emission in hadron-hadron and e + e - collisions was developed. It focuses on the idea of the wide range of values for the total angular momentum in hadron-hadron collisions. An extension of this consideration yields a theory for the momentum distribution of the outgoing particles which agrees with bar pp and e + e - collision experiments. The results and conclusions of this theory have been extrapolated to higher energies and yielded many predictions which can be experimentally tested. 37 refs
Hot Strange Hadronic Matter in an Effective Model
Institute of Scientific and Technical Information of China (English)
QIAN Wei-Liang; SU Ru-Keng; SONG Hong-Qiu
2003-01-01
An effective model used to describe the strange hadronic matter with nucleons, Λ-hyperons, and Ξ-hyperonsis extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fractiondependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy andpressure, as well as the equation of state of the matter, are given.
Hot Strange Hadronic Matter in an Effective Model
Institute of Scientific and Technical Information of China (English)
QIANWei-Liang; SURu-Keng; SONGHong-Qiu
2003-01-01
An effective model used to describe the strange hadronic matter with nucleons, A-hyperons, and [I]-hyperons is extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fraction dependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy and pressure, as well as the equation of state of the matter, are given.
Di-hadron azimuthal correlation and Mach-like cone structure in a parton/hadron transport model
International Nuclear Information System (INIS)
Ma, G.L.; Zhang, S.; Ma, Y.G.; Huang, H.Z.; Cai, X.Z.; Chen, J.H.; He, Z.J.; Long, J.L.; Shen, W.Q.; Shi, X.H.; Zuo, J.X.
2006-01-01
In the framework of a multi-phase transport model (AMPT) with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles have been studied by the mixing-event technique. The momentum ranges of these particles are 3 T trig T assoc T trig T assoc NN =200 GeV. A Mach-like structure has been observed in correlation functions for central collisions. By comparing scenarios with and without parton cascade and hadronic rescattering, we show that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure of the associated particle azimuthal correlations. The contribution of hadronic dynamical process cannot be ignored in the emergence of Mach-like correlations of the soft scattered associated hadrons. However, hadronic rescattering alone cannot reproduce experimental amplitude of Mach-like cone on away-side, and the parton cascade process is essential to describe experimental amplitude of Mach-like cone on away-side. In addition, both the associated multiplicity and the sum of p T decrease, while the T > increases, with the impact parameter in the AMPT model including partonic dynamics from string melting scenario
Test of hadronic interaction models with the KASCADE-Grande muon data
Directory of Open Access Journals (Sweden)
Schieler H.
2013-06-01
Full Text Available KASCADE-Grande is an air-shower observatory devoted for the detection of cosmic rays with energies in the interval of 1014 – 1018 eV, where the Grande array is responsible for the higher energy range. The experiment comprises different detection systems which allow precise measurements of the charged, electron and muon numbers of extensive air-showers (EAS. These data is employed not only to reconstruct the properties of the primary cosmic-ray particle but also to test hadronic interaction models at high energies. In this contribution, predictions of the muon content of EAS from QGSJET II-2, SIBYLL 2.1 and EPOS 1.99 are confronted with the experimental measurements performed with the KASCADE-Grande experiment in order to test the validity of these hadronic models commonly used in EAS simulations.
International Nuclear Information System (INIS)
Ji, C.R.
1999-01-01
This report details research progress and results obtained during the entire period of the research project. In compliance with grant requirements the Principal Investigator, Professor Chueng-Ryong Ji, has conducted a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. This Principal Investigator has devoted 50% of his time during the academic year and 100% of his time in the summer. This percent effort has continued during the entire period of the grant. The new, significant research results are briefly summarized in this report. Finally, full, detailed descriptions of completed work can be found in the project publications which are listed at the end of this technical report
Hadron spectrum in quenched lattice QCD and quark potential models
International Nuclear Information System (INIS)
Iwasaki, Y.; Yoshie, T.
1989-01-01
We show that the quenched lattice QCD gives a hadron spectrum which remarkably agrees with that of quark potential models for quark mass m q ≥ m strange , even when one uses the standard one-plaquette gauge action. This is contrary to what is stated in the literature. We clarify the reason of the discrepancy, paying close attention to systematic errors in numerical calculations. (orig.)
Nuclear symmetry energy in density dependent hadronic models
International Nuclear Information System (INIS)
Haddad, S.
2008-12-01
The density dependence of the symmetry energy and the correlation between parameters of the symmetry energy and the neutron skin thickness in the nucleus 208 Pb are investigated in relativistic Hadronic models. The dependency of the symmetry energy on density is linear around saturation density. Correlation exists between the neutron skin thickness in the nucleus 208 Pb and the value of the nuclear symmetry energy at saturation density, but not with the slope of the symmetry energy at saturation density. (author)
Quasinuclear colored quark model for hadrons
International Nuclear Information System (INIS)
Lipkin, H.J.
1978-09-01
Lectures are presented in which a quasinuclear constituent quark model in which constituent quarks are assumed to be made of constituent interacting with a two-body color-exchange logarithmic potential is considered. The color degree of freedom is discussed in detail. Some properties of the logarithmic potential and the definition of the quasinuclear model and its validity, and a comparison of some of its predictions with experiment are described. 31 references
A correlated-cluster model and the ridge phenomenon in hadron-hadron collisions
Sanchis-Lozano, Miguel-Angel
2017-03-10
A study of the near-side ridge phenomenon in hadron-hadron collisions based on a cluster picture of multiparticle production is presented. The near-side ridge effect is shown to have a natural explanation in this context provided that clusters are produced in a correlated manner in the collision transverse plane.
Soft hadronic production by ECCO in the geometrical branching model
International Nuclear Information System (INIS)
Pan, J.; Hwa, R.C.
1993-01-01
Soft production of hadrons in hadronic collisions is described in the geometrical branching model and implemented by the eikonal cascade code (ECCO). It is shown that the major global features of multiparticle production can be reproduced by one essential characterization of the dynamics of branching, namely, a scaling law for the mass distribution of daughter clusters. Without further adjustment of any parameters, the event generator can produce local features of multiplicity fluctuations in agreement with the NA22 intermittency data. The scaling exponent ν is determined to be 1.522 at √s =22 GeV, independent of the dimensionality of the intermittency analysis. It is shown that ν is approximately independent of the collision energy
Consideration of the vacuum of QCD in a composite quark model. Strange hadrons
International Nuclear Information System (INIS)
Dorokhov, A.E.; Kochelev, N.I.
1986-01-01
The method of inclusion of QCD vacuum condensates within the quark composite model is generalized to the case of hadrons containing strange quarks. The mass formula for such hadrons is obtained. The mass of strange quark is defined by analysing the energy spectrum of hadron ground states. The mixing angles of pseudoscalar mesons are estimated
General method of calculation of any hadronic decay in the 3P0 model
International Nuclear Information System (INIS)
Roberts, W.
1992-01-01
The 3 P 0 pair creation model of hadron decays is generalized to be applicable to the decay of any hadron. The wave function of the decaying hadron is expanded in terms of two clusters. The transition amplitudes is derived for any combination of angular momenta, and for general wave functions in momentum space, expanded in terms of Gaussians times polynomials. (authors)
Interacting hadron resonance gas model in the K -matrix formalism
Dash, Ashutosh; Samanta, Subhasis; Mohanty, Bedangadas
2018-05-01
An extension of hadron resonance gas (HRG) model is constructed to include interactions using relativistic virial expansion of partition function. The noninteracting part of the expansion contains all the stable baryons and mesons and the interacting part contains all the higher mass resonances which decay into two stable hadrons. The virial coefficients are related to the phase shifts which are calculated using K -matrix formalism in the present work. We have calculated various thermodynamics quantities like pressure, energy density, and entropy density of the system. A comparison of thermodynamic quantities with noninteracting HRG model, calculated using the same number of hadrons, shows that the results of the above formalism are larger. A good agreement between equation of state calculated in K -matrix formalism and lattice QCD simulations is observed. Specifically, the lattice QCD calculated interaction measure is well described in our formalism. We have also calculated second-order fluctuations and correlations of conserved charges in K -matrix formalism. We observe a good agreement of second-order fluctuations and baryon-strangeness correlation with lattice data below the crossover temperature.
Microscopic models for hadronic form factors and vertex functions
International Nuclear Information System (INIS)
Santhanam, I.; Bhatnagar, S.; Mitra, A.N.
1990-01-01
We review the status of nucleon (N) and few-nucleon form factors (f.f.'s) from the view-point of a gradual unfolding of successively inner degrees of freedom (d.o.f.) with increase in q 2 . To this end we focus attention on the problem of a microscopic formulation of hadronic vertex functions (v.f.) from the point of view of their key role in understanding the physics of a large variety of few-hadron reactions on the one hand, and their practical usefulness in articulating the internal dynamics of hadron and few-hadron systems on the other hand. The criterion of an integrated view from low-energy spectroscopy to high-q 2 amplitudes is employed to emphasize the desirability of formulations in terms of relativistic dynamical equations based on Lorentz and gauge invariance in preference to phenomenological models, which often require additional assumptions beyond their original premises to extend their applicability domains. In this respect, the practical possibilities of the Bethe-Salpeter equation (BSE) in articulating the necessary dynamical ingredients are emphasized on a two-tier basis, the basis constants (3) being pre-determined from the mass spectral data (1 st stage) in preparation for the construction of the hadron-quark vertex functions (2 nd stage). An explicit construction is outlined for meson-quark and baryon-quark vertex functions as well as of meson-nucleon vertex functions in a stepwise fashion. The role of the latter as basic parameter-free ingredients is discussed for possible use in the more serious treatment in the current literature of quark-meson level (α) and meson-isobar (β) d.o.f. in 2-N and 3-N form factor studies. Since most of these studies are characterized by the use of RGM techniques at the six-quark level, a comparative discussion is also given of several contemporary RGM based models. Finally, the concrete prospects for employing such hardon-quark vertex functions for evaluating pp-bar annihilation amplitudes are briefly indicated
Search for the Higgs Boson in the All-Hadronic Final State Using the CDF II Detector
Energy Technology Data Exchange (ETDEWEB)
Devoto, Francesco [Univ. of Helsinki (Finland)
2013-01-01
This thesis reports the result of a search for the Standard Model Higgs boson in events containing four reconstructed jets associated with quarks. For masses below 135 GeV/c^{2}, the Higgs boson decays to bottom-antibottom quark pairs are dominant and result primarily in two hadronic jets. An additional two jets can be produced in the hadronic decay of a W or Z boson produced in association with the Higgs boson, or from the incoming quarks that produced the Higgs boson through the vector boson fusion process. The search is performed using a sample of s = sqrt(1.96) TeV proton-antiproton collisions corresponding to an integrated luminosity of 9.45 fb^{-1} recorded by the CDF II detector. The data are in agreement with the background model and 95% credibility level upper limits on Higgs boson production are set as a function of the Higgs boson mass. The median expected (observed) limit for a 125 GeV/c^{2} Higgs boson is 11.0 (9.0) times the predicted standard model rate.
Model-independent determination of hadronic neutral-current couplings
International Nuclear Information System (INIS)
Claudson, M.; Paschos, E.A.; Strait, J.; Sulak, L.R.
1979-01-01
Completion of a second generation of experiments on neutrino-induced neutral-current reactions allows a more discriminating study of neutral-current couplings to hadrons. To minimize the sensitivity to model-dependent analyses of inclusive and exclusive pion data, we base our work on measurements of deep-inelastic and elastic reactions alone. Within the regions allowed by the deep-inelastic data for scattering on isoscalar targets, the coupling constants are fit to the q 2 dependence of the neutrino-proton elastic scattering data. This procedure initially yields two solutions for the couplings. One of these, at theta/sub L/ = 55 0 and theta/sub R/ = 205 0 , is predominantly isoscalar and therefore is ruled out by only qualitative consideration of exclusive pion data. The other solution at theta/sub D/ = 140 0 and and theta/sub R/ = 330 0 , is thus a unique determination of the hadronic neutral-current couplings. It coincides with solution A obtained in earlier work, and is insensitive to variations of M/sub A/ within 2 standard deviations of the world average. When constrained to the coupling constants required by the Weinberg-Salam model, the fit agrees with the data to within 1 standard deviation
Geant4 Hadronic Cascade Models and CMS Data Analysis : Computational Challenges in the LHC era
Heikkinen, Aatos
This work belongs to the field of computational high-energy physics (HEP). The key methods used in this thesis work to meet the challenges raised by the Large Hadron Collider (LHC) era experiments are object-orientation with software engineering, Monte Carlo simulation, the computer technology of clusters, and artificial neural networks. The first aspect discussed is the development of hadronic cascade models, used for the accurate simulation of medium-energy hadron-nucleus reactions, up to 10 GeV. These models are typically needed in hadronic calorimeter studies and in the estimation of radiation backgrounds. Various applications outside HEP include the medical field (such as hadron treatment simulations), space science (satellite shielding), and nuclear physics (spallation studies). Validation results are presented for several significant improvements released in Geant4 simulation tool, and the significance of the new models for computing in the Large Hadron Collider era is estimated. In particular, we es...
Effective models of new physics at the Large Hadron Collider
International Nuclear Information System (INIS)
Llodra-Perez, J.
2011-07-01
With the start of the Large Hadron Collider runs, in 2010, particle physicists will be soon able to have a better understanding of the electroweak symmetry breaking. They might also answer to many experimental and theoretical open questions raised by the Standard Model. Surfing on this really favorable situation, we will first present in this thesis a highly model-independent parametrization in order to characterize the new physics effects on mechanisms of production and decay of the Higgs boson. This original tool will be easily and directly usable in data analysis of CMS and ATLAS, the huge generalist experiments of LHC. It will help indeed to exclude or validate significantly some new theories beyond the Standard Model. In another approach, based on model-building, we considered a scenario of new physics, where the Standard Model fields can propagate in a flat six-dimensional space. The new spatial extra-dimensions will be compactified on a Real Projective Plane. This orbifold is the unique six-dimensional geometry which possesses chiral fermions and a natural Dark Matter candidate. The scalar photon, which is the lightest particle of the first Kaluza-Klein tier, is stabilized by a symmetry relic of the six dimension Lorentz invariance. Using the current constraints from cosmological observations and our first analytical calculation, we derived a characteristic mass range around few hundred GeV for the Kaluza-Klein scalar photon. Therefore the new states of our Universal Extra-Dimension model are light enough to be produced through clear signatures at the Large Hadron Collider. So we used a more sophisticated analysis of particle mass spectrum and couplings, including radiative corrections at one-loop, in order to establish our first predictions and constraints on the expected LHC phenomenology. (author)
Studies on phenomenological hadron models with chiral symmetry
International Nuclear Information System (INIS)
Rathske, E.
1991-12-01
In this report we consider, in the context of phenomenological models for hadrons, several aspects of Skyrme-type and hybrid bag models. In the first of the two central parts we discuss two qualitatively different generalizations of the minimal SU(2) Skyrme model. One of these consists in adding to the Lagrangian density a symmetric term of fourth order in the field derivatives. Its consequences are determined for solutions and observables by analytical and numerical investigations. In the other we propose a contribution for explicit isospin symmetry breaking in the mesonic as well as the baryonic sector. Together with the standard nonlinear σ-model term it allows for exact time-dependent classical soliton solutions. Their quantization leads to a quantitative connection between the hadronic isospin mass differenced of pions and nucleons. The second main part of this report is devoted to the generalization of SU(2) bag models under the aspect of chiral symmetry. We first show that the construction of appropriate surface terms in the Lagrangian density necessitates the introduction of dynamical bosonic degrees of freedom. This allows for a variety of bag scenarios (including the 'endopionic' bag). We then consider explicit isospin symmetry breaking for hybrid bag models with a nonlinear mesonic sector. An intimate relationship is revealed between the effects of a quark mass difference and the time-dependent bosonic solutions found for the purely mesonic case. It is reflected in a nontrivial interdependence between quark and meson masses, bag radius and chiral angle. We provide an especially extensive list of references for the topics discussed in this report. (orig.) [de
The deconfinement phase transition, hadronization and the NJL model
International Nuclear Information System (INIS)
Raha, Sibaji
2000-01-01
One of the confident predictions of QCD is that at sufficiently high temperature and/or density, hadronic matter should undergo a thermodynamic phase transition to a color deconfined state of matter-popularly called the Quark-Gluon Plasma (QGP). In low energy effective theories of Quantum Chromodynamics (QCD), one usually talks of the chiral transition for which a well defined order parameter exists. We investigate the dissociation of pions and kaons in a medium of hot quark matter described by the Nambu-Jona Lasinio (NJL) model. The decay widths of pion and kaon are found to be large but finite at temperature much higher than the critical temperature for the chiral (or deconfinement) transition, the kaon decay width being much larger. Thus pions and even kaons (with a lower density compared to pions) may coexist with quarks and gluons at such high temperatures. On the basis of such premises, we investigate the process of hadronization in quark-gluon plasma with special emphasis on whether such processes shed any light on acceptable low energy effective theories of QCD
Hot Strange Hadronic Matter in an Effective Model
Qian, Wei-Liang; Su, Ru-Keng; Song, Hong-Qiu
2003-10-01
An effective model used to describe the strange hadronic matter with nucleons, Λ-hyperons, and Ξ-hyperons is extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fraction dependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy and pressure, as well as the equation of state of the matter, are given. The project supported in part by National Natural Science Foundation of China under Grant Nos. 10075071, 10047005, 19947001, 19975010, and 10235030, and the CAS Knowledge Innovation Project No. KJCX2-N11. Also supported by the State Key Basic Research Development Program under Grant No. G200077400 and the Exploration Project of Knowledge Innovation Program of the Chinese Academy of Sciences
Conserved number fluctuations in a hadron resonance gas model
International Nuclear Information System (INIS)
Garg, P.; Mishra, D.K.; Netrakanti, P.K.; Mohanty, B.; Mohanty, A.K.; Singh, B.K.; Xu, N.
2013-01-01
Net-baryon, net-charge and net-strangeness number fluctuations in high energy heavy-ion collisions are discussed within the framework of a hadron resonance gas (HRG) model. Ratios of the conserved number susceptibilities calculated in HRG are being compared to the corresponding experimental measurements to extract information about the freeze-out condition and the phase structure of systems with strong interactions. We emphasize the importance of considering the actual experimental acceptances in terms of kinematics (pseudorapidity (η) and transverse momentum (p T )), the detected charge state, effect of collective motion of particles in the system and the resonance decay contributions before comparisons are made to the theoretical calculations. In this work, based on HRG model, we report that the net-baryon number fluctuations are least affected by experimental acceptances compared to the net-charge and net-strangeness number fluctuations
Nuclear ``pasta'' phase within density dependent hadronic models
Avancini, S. S.; Brito, L.; Marinelli, J. R.; Menezes, D. P.; de Moraes, M. M. W.; Providência, C.; Santos, A. M.
2009-03-01
In the present paper, we investigate the onset of the “pasta” phase with different parametrizations of the density dependent hadronic model and compare the results with one of the usual parametrizations of the nonlinear Walecka model. The influence of the scalar-isovector virtual δ meson is shown. At zero temperature, two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature, only the coexistence phases method is used. npe matter with fixed proton fractions and in β equilibrium are studied. We compare our results with restrictions imposed on the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations.
Nuclear 'pasta' phase within density dependent hadronic models
International Nuclear Information System (INIS)
Avancini, S. S.; Marinelli, J. R.; Menezes, D. P.; Moraes, M. M. W. de; Brito, L.; Providencia, C.; Santos, A. M.
2009-01-01
In the present paper, we investigate the onset of the 'pasta' phase with different parametrizations of the density dependent hadronic model and compare the results with one of the usual parametrizations of the nonlinear Walecka model. The influence of the scalar-isovector virtual δ meson is shown. At zero temperature, two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature, only the coexistence phases method is used. npe matter with fixed proton fractions and in β equilibrium are studied. We compare our results with restrictions imposed on the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations
Electromagnetic moments of hadrons and quarks in a hybrid model
International Nuclear Information System (INIS)
Gerasimov, S.B.
1989-01-01
Magnetic moments of baryons are analyzed on the basis of general sum rules following from the theory of broken symmetries and quark models including the relativistic effects and hadronic corrections due to the meson exchange currents. A new sum rule is proposed for the hyperon magnetic moments, which is in accord with the most precise new data and also with a theory of the electromagnetic ΛΣ 0 mixing. The numerical values of the quark electromagnetic moments are obtained within a hybrid model treating the pion cloud effects through the local coupling of the pion field with the constituent massive quarks. Possible sensitivity of the weak neutral current magnetic moments to violation of the Okubo-Zweig-Izuki rule is emphasized nand discussed. 39 refs.; 1 fig
Strangeness production in hadronic and nuclear collisions in the dual parton model
International Nuclear Information System (INIS)
Capella, A.; Tran Thanh Van, J.; Ranft, J.
1993-01-01
Λ, antiΛ and K s 0 production is studied in a Monte Carlo Dual Parton model for hadron-hadron, hadron-nucleus and nucleus-nucleus collisions with a SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation. Additionally, (qq)-(antiqantiq) production from the sea was introduced into the chain formation process with the same probability as for the q → qq branching within the chain decay process. This together with the popcorn mechanism of diquark fragmentation result in a new central component of hyperon production, which was not present in previous versions of the model. With these assumptions rapidity distributions and multiplicity ratios for strange particles in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions are compared to a comprehensive collection of experimental data. 5 figs., 2 tabs., 15 refs
Multiplicity distributions in a thermodynamical model of hadron production in e+e- collisions
International Nuclear Information System (INIS)
Becattini, F.; Giovannini, A.; Lupia, S.
1996-01-01
Predictions of a thermodynamical model of hadron production for multiplicity distributions in e + e - annihilations at LEP and PEP-PETRA centre of mass energies are shown. The production process is described as a two-step process in which primary hadrons emitted from the thermal source decay into final observable particles. The final charged track multiplicity distributions turn out to be of negative binomial type and are in quite good agreement with experimental observations. The average number of clans calculated from fitted negative binomial coincides with the average number of primary hadrons predicted by the thermodynamical model, suggesting that clans should be identified with primary hadrons. (orig.)
Critical behavior of mean-field hadronic models for warm nuclear matter
International Nuclear Information System (INIS)
Silva, J.B.; Lourenco, O.; Delfino, A.; Martins, J.S. Sa; Dutra, M.
2008-01-01
We study a set of hadronic mean-field models in the liquid-gas phase transition regime and calculate their critical parameters. The discussion is unified by scaling the coexistence curves in terms of these critical parameters. We study the models close to spinodal points, where they also present critical behavior. Inspired by signals of criticality shown in fragmentation experiments, we analyze two different scenarios in which such behavior would be expected: (i) the stability limits of a metastable system with vanishing external pressure; and (ii) the critical point of a gas-liquid phase equilibrium system for which the Maxwell construction applies. Spinodal and coexistence curves show the regions in which model dependence arises. Unexpectedly, this model dependence does not manifest if one calculates the thermal incompressibility of the models
Exactly solvable model of phase transition between hadron and quark-gluon-matter
International Nuclear Information System (INIS)
Gorenstein, M.I.; Petrov, V.K.; Shelest, V.P.; Zinovjev, G.M.
1982-01-01
An exactly solvable model of phase transition between hadron and quark-gluon matter is proposed. The hadron phase of this model is considered as a gas of bags filled by point massless constituents. The mass and volume spectrum of the bag is found. The thermodynamical characteristics of a bag gas in the neighbourhood of a phase transition point are ascertained in analytical form
Hadron form factors in the constituent quark model
International Nuclear Information System (INIS)
Cardarelli, F.; Salme', G.; Simula, S.; Pace, E.
1998-01-01
Hadron electromagnetic form factors are evaluated in a light-front constituent quark model based on the eigenfunctions of a mass operator, including in the q-q interaction a confining term and a one-gluon-exchange term (OGE). The spin-dependent part of the interaction plays an essential role for obtaining both a proper fit of the experimental nucleon electromagnetic form factors and the faster than dipole decrease of the magnetic N-P 33 (1232) transition form factor. The effects of the D wave, produced by the tensor part of the OGE interaction, on the quadrupole and Coulomb N-P 33 (1232) transition form factors have been found to be negligible. (author)
Hadronic models and experimental data for the neutrino beam production
Collazuol, G; Guglielmi, A M; Sala, P R
2000-01-01
The predictions of meson production by 450 GeV/c protons on Be using the Monte Carlo FLUKA standalone and GEANT-FLUKA and GEANT-GHEISHA in GEANT are compared with available experimental measurements. The comparison enlightens the improvements of the hadronic generator models of the present standalone code FLUKA with respect to the 1992 version which is embedded into GEANT-FLUKA. Worse results were obtained with the GHEISHA package. A complete simulation of the SPS neutrino beam line at CERN showed significant variations in the intensity and composition of the neutrino beam when FLUKA standalone instead of the GEANT-FLUKA package is used to simulate particle production in the Be target.
Hadronic models and experimental data for the neutrino beam production
International Nuclear Information System (INIS)
Collazuol, G.; Ferrari, A.; Guglielmi, A.; Sala, P.R.
2000-01-01
The predictions of meson production by 450 GeV/c protons on Be using the Monte Carlo FLUKA standalone and GEANT-FLUKA and GEANT-GHEISHA in GEANT are compared with available experimental measurements. The comparison enlightens the improvements of the hadronic generator models of the present standalone code FLUKA with respect to the 1992 version which is embedded into GEANT-FLUKA. Worse results were obtained with the GHEISHA package. A complete simulation of the SPS neutrino beam line at CERN showed significant variations in the intensity and composition of the neutrino beam when FLUKA standalone instead of the GEANT-FLUKA package is used to simulate particle production in the Be target
The influence of fragmentation models in the production of hadron ...
Indian Academy of Sciences (India)
The analysis of electron–positron annihilations to hadrons at high energies shows that apart from two-jet events, there are also signs of three-jet events which are interpreted according to the QCD, as a gluon radiated by a quark. In this paper, we investigate the fragmentation of quarks and gluons to hadron jets. We show ...
Anisotropic superfluidity of hadronic matter
International Nuclear Information System (INIS)
Chela Flores, J.
1977-10-01
From a model of strong interactions with important general features (f-g model) and from recent experiments of Rudnick and co-workers on thin films of helium II, hadronic matter is considered as a new manifestation of anisotropic superfluidity. In order to test the validity of the suggestion, some qualitative features of multiparticle production of hadrons are considered, and found to have a natural explanation. A prediction is made following a recent experiment on π + p collisions
A non-perturbative approach to jet cross-sections and a new model for hadron-hadron interactions
International Nuclear Information System (INIS)
Andersson, B.
1986-01-01
The author discusses two subjects in this work. The first is a description of a non-perturbative approach to calculate the probabilities to obtain a particular state of confined force field in a hard interaction like e/sup +/e/sup -/ annihilation. This approach has been discussed previously by the author. There are at this time many more results of the program, in particular, some rather puzzling and disturbing ones as compared to the results obtained in perturbative QCD. The second subject is a new approach to hadron-hadron inelastic scattering. A model for these interactions based upon multiple perturbative parton interactions and subsequent string-stretching and breaking has been formulated by others in earlier works
Large degeneracy of excited hadrons and quark models
International Nuclear Information System (INIS)
Bicudo, P.
2007-01-01
The pattern of a large approximate degeneracy of the excited hadron spectra (larger than the chiral restoration degeneracy) is present in the recent experimental report of Bugg. Here we try to model this degeneracy with state of the art quark models. We review how the Coulomb Gauge chiral invariant and confining Bethe-Salpeter equation simplifies in the case of very excited quark-antiquark mesons, including angular or radial excitations, to a Salpeter equation with an ultrarelativistic kinetic energy with the spin-independent part of the potential. The resulting meson spectrum is solved, and the excited chiral restoration is recovered, for all mesons with J>0. Applying the ultrarelativistic simplification to a linear equal-time potential, linear Regge trajectories are obtained, for both angular and radial excitations. The spectrum is also compared with the semiclassical Bohr-Sommerfeld quantization relation. However, the excited angular and radial spectra do not coincide exactly. We then search, with the classical Bertrand theorem, for central potentials producing always classical closed orbits with the ultrarelativistic kinetic energy. We find that no such potential exists, and this implies that no exact larger degeneracy can be obtained in our equal-time framework, with a single principal quantum number comparable to the nonrelativistic Coulomb or harmonic oscillator potentials. Nevertheless we find it plausible that the large experimental approximate degeneracy will be modeled in the future by quark models beyond the present state of the art
International Nuclear Information System (INIS)
Bugrij, G.; Jenkovsky, L.; Martynov, E.
1994-01-01
These Proceedings contain the contributions to the Workshop HADRONS-94,held in Uzhgorod between September 7-11,1994. They covers the topics: - elastic and diffractive scattering of hadrons and nuclei; -small-x and spin physics; - meson and baryon spectroscopy; - dual and string models; - collective properties of the strongly interacting matter
Energy Technology Data Exchange (ETDEWEB)
Bugrij, G; Jenkovsky, L; Martynov, E [eds.
1994-12-31
These Proceedings contain the contributions to the Workshop HADRONS-94,held in Uzhgorod between September 7-11,1994. They covers the topics: - elastic and diffractive scattering of hadrons and nuclei; -small-x and spin physics; - meson and baryon spectroscopy; - dual and string models; - collective properties of the strongly interacting matter.
Hadron structure in a simple model of quark/nuclear matter
International Nuclear Information System (INIS)
Horowitz, C.J.; Moniz, E.J.; Negele, J.W.
1985-01-01
We study a simple model for one-dimensional hadron matter with many of the essential features needed for examining the transition from nuclear to quark matter and the limitations of models based upon hadron rather than quark degrees of freedom. The dynamics are generated entirely by the quark confining force and exchange symmetry. Using Monte Carlo techniques, the ground-state energy, single-quark momentum distribution, and quark correlation function are calculated for uniform matter as a function of density. The quark confinement scale in the medium increases substantially with increasing density. This change is evident in the correlation function and momentum distribution, in qualitative agreement with the changes observed in deep-inelastic lepton scattering. Nevertheless, the ground-state energy is smooth throughout the transition to quark matter and is described remarkably well by an effective hadron theory based on a phenomenological hadron-hadron potential
International Nuclear Information System (INIS)
Oka, Makoto
2012-01-01
Spectra of hadrons show various and complex structures due to the strong coupling constants of the quantum chromodynamics (QCD) constituting its fundamental theory. For their understandings, two parameters, i.e., (1) the quark mass and (2) their excitation energies are playing important roles. In low energies, for example, rather simple structures similar to the positronium appear in the heavy quarks such as charms and bottoms. It has been, however, strongly suggested by the recent experiments that the molecular resonant state shows up when the threshold to decay to mesons is exceeded. On the other hand, chiral symmetry and its breaking play important roles in the dynamics of light quarks. Strange quarks are in between and show special behaviors. In the present lecture, the fundamental concept of the hadron spectroscopy based on the QCD is expounded to illustrate the present understandings and problems of the hadron spectroscopy. Sections are composed of 1. Introduction, 2. Fundamental Concepts (hadrons, quarks and QCD), 3. Quark models and exotic hadrons, 4. Lattice QCD and QCD sum rules. For sections 1 to 3, only outline of the concepts is described because of the limited space. Exotic hadrons, many quark pictures of light hadrons and number of quarks in hadrons are described briefly. (S. Funahashi)
An SU(5) grand unified model with hadrons as nontopological solitons. Pt. 1
International Nuclear Information System (INIS)
Chen Shihao
1994-01-01
A new grand unified model containing the known three generations of quark and lepton in which hadrons are regarded as nontopological solitons formed from quarks is presented. According to the model leptons and quarks are the same in essence. The differences between them are caused by spontaneous symmetry breaking. When a quark is located inside a hadron, its properties will be the same as those of a known quark and its mass very small. When a quark is outside hadrons, its properties will be the same as those of a known lepton, its mass very large and it will rapidly decay. Except defining charge Q 0 and fermion number F 0 which are exactly conserved, we also define interior colour, interior charge and interior fermion number approximately conserved inside a hadron. The (L-B) conservation in the known SU(5) model corresponds to the fermion number F 0 conservation in the present model
International Nuclear Information System (INIS)
Fowler, G.N.; Navarra, F.S.; Plumer, M.; Lawrence Berkeley Laboratory, Nuclear Science Division, Berkeley, California 94720); Vourdas, A.; Weiner, R.M.
1989-01-01
The interacting gluon model developed to describe the inelasticity distribution in hadron-nucleon collisions has been generalized and applied to hadron-nucleus and nucleus-nucleus interactions. Leading particle spectra and energy distributions in hadron-nucleus and nucleus-nucleus collisions are calculated
Total cross sections of hadron interactions at high energies in low constituents number model
International Nuclear Information System (INIS)
Abramovskij, V.A.; Radchenko, N.V.
2009-01-01
We consider QCD hadrons interaction model in which gluons density is low in initial state wave function in rapidity space and real hadrons are produced from color strings decay. In this model behavior of total cross sections of pp, pp bar, π ± p, K ± p, γp, and γγ interactions is well described. The value of proton-proton total cross section at LHC energy is predicted
International Nuclear Information System (INIS)
Gridneva, S.A.; Rus'kin, V.I.
1980-01-01
Basic features of the statistical model of multiple hadron production based on microcanonical distribution and taking into account the laws of conservation of total angular momentum, isotopic spin, p-, G-, C-eveness and Bose-Einstein statistics requirements are given. The model predictions are compared with experimental data on anti NN annihilation at rest and e + e - annihilation in hadrons at annihilation total energy from 2 to 3 GeV [ru
A Color Mutation Hadronic Soft Interaction Model -- Eikonal Formalism and Branching Evolution
Cao, Zhen
1998-01-01
ECOMB is established as a hadronic multiparticle production generator by soft interaction. It incorporates the eikonal formalism, parton model, color mutation, branching, resonance production and decay. A partonic cluster, being color-neutral initially, splits into smaller color-neutral clusters successively due to the color mutation of the quarks. The process stops at hadronic resonance, $q\\bar q$ pair, formation. The model contains self-similar dynamics and exhibits scaling behavior in the ...
Confinement and hadron-hadron interactions by general relativistic methods
Recami, Erasmo
By postulating covariance of physical laws under global dilations, one can describe gravitational and strong interactions in a unified way. Namely, in terms of the new discrete dilational degree of freedom, our cosmos and hadrons can be regarded as finite, similar systems. And a discrete hierarchy of finite ``universes'' may be defined, which are governed by fields with strengths inversally proportional to their radii; in each universe an Equivalence Principle holds, so that the relevant field can be there geometrized. Scaled-down Einstein equations -with cosmological term- are assumed to hold inside hadrons (= strong micro-cosmoses); and they yield in a natural way classical confinement, as well as ``asymptotic freedom'', of the hadron constituents. In other words, the association of strong micro-universes of Friedmann type with hadrons (i.e., applying the methods of General Relativity to subnuclear particle physics) allows avoiding recourse to phenomenological models such as the Bag Model. Inside hadrons we have to deal with a tensorial field (= strong gravity), and hadron constituents are supposed to exchange spin-2 ``gluons''. Our approach allows us also to write down a tensorial, bi-scale field theory of hadron-hadron interactions, based on modified Einstein-type equations here proposed for strong interactions in our space. We obtain in particular: (i) the correct Yukawa behaviour of the strong scalar potential at the static limit and for r>~l fm; (ii) the value of hadron radii. As a byproduct, we derive a whole ``numerology'', connecting our gravitational cosmos with the strong micro-cosmoses (hadrons), such that it does imply no variation of G with the epoch. Finally, since a structute of the ``micro-universe'' type seems to be characteristic even of leptons, a hope for the future is including also weak interactions in our classical unification of the fundamental forces.
Hadronic J/psi and charmed particle production and correlating quark rearrangement model
International Nuclear Information System (INIS)
Nishitani, Tadashi
1979-01-01
On the basis of the correlating quark rearrangement model, the exclusive and inclusive production cross sections of J/psi and charmed particles in hadron collisions are calculated. It is shown that the inclusive production cross section of charmed particles is several tens of μb at p sub( l) -- 100 GeV/c in hadron collisions. The OZI rule is discussed in connection with the production mechanism of J/psi particles. (author)
International Nuclear Information System (INIS)
Bunce, G.
1984-01-01
Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain
Form factors and structure functions of hadrons in parton model
International Nuclear Information System (INIS)
Volkonskij, N.Yu.
1979-01-01
The hadron charge form factors and their relation to the deep-inelastic lepton-production structure functions in the regions of asymptotically high and small momentum transfer Q 2 are studied. The nucleon and pion charge radii are calculated. The results of calculations are in good agreement with the experimental data. The K- and D-meson charge radii are estimated. In the region of asymptotically high Q 2 the possibility of Drell-Yan-West relation violation is analyzed. It is shown, that for pseudoscalar mesons this relation is violated. The relation between the proton and neutron form factor asymptotics is obtained
New space--time model for hadron--nucleus collisions at high energies
International Nuclear Information System (INIS)
Bialkowski, G.; Chiu, C.B.; Tow, D.M.
1976-12-01
A new space-time model for hadron-nucleus collisions is proposed, where particles at the instant of creation are immature and their maturity rate is enhanced in the presence of other hadronic matter, as in a nucleus. With only one free parameter, the model can explain dn/sub A//sup p//d eta, dn/sub A//sup pi//d eta, R/sub A//sup p/(E/sub L/), and the A-dependences of sigma/sub in/sup pA/ and sigma/sub in/sup pi A/
International Nuclear Information System (INIS)
Close, F.E.
1987-09-01
The standard theory of colour forces (Quantum Chromodynamics) suggests that in addition to the familiar hadrons made of quarks, there should exist new states where coloured gluons play an essential dynamical role. The author reviews the theoretical predictions for the properties of these ''glueballs'' and of states containing resonating quarks and gluons. Attempts are made to highlight those features which are common to several models in the literature. Experimental candidates are confronted with the models. No clear cut signal for a gluonic hadron yet exists; consequently what future data are required to determine the constituency of some popular candidates is considered. (author)
INSPIRE-00425747; McMahon, Stephen J
2015-01-01
ATLAS is a particle physics experiment at the Large Hadron Collider (LHC) that detects proton-proton collisions at a centre of mass energy of 14 TeV. The Semiconductor Tracker is part of the Inner Detector, implemented using silicon microstrip detectors with binary read-out, providing momentum measurement of charged particles with excellent resolution. The operation of the LHC and the ATLAS experiment started in 2010, with ten years of operation expected until major upgrades are needed in the accelerator and the experiments. The ATLAS tracker will need to be completely replaced due to the radiation damage and occupancy of some detector elements and the data links at high luminosities. These upgrades after the first ten years of operation are named the Phase-II Upgrade and involve a re-design of the LHC, resulting in the High Luminosity Large Hadron Collider (HL-LHC). This thesis presents the work carried out in the testing of the ATLAS Phase-II Upgrade electronic systems in the future strips tracker a...
Adler function and hadronic contribution to the muon g-2 in a nonlocal chiral quark model
International Nuclear Information System (INIS)
Dorokhov, Alexander E.
2004-01-01
The behavior of the vector Adler function at spacelike momenta is studied in the framework of a covariant chiral quark model with instantonlike quark-quark interaction. This function describes the transition between the high-energy asymptotically free region of almost massless current quarks to the low-energy hadronized regime with massive constituent quarks. The model reproduces the Adler function and V-A correlator extracted from the ALEPH and OPAL data on hadronic τ lepton decays, transformed into the Euclidean domain via dispersion relations. The leading order contribution from the hadronic part of the photon vacuum polarization to the anomalous magnetic moment of the muon, a μ hvp(1) , is estimated
Energy Technology Data Exchange (ETDEWEB)
Becattini, F. [Florence Univ. (Italy)]|[Istituto Nazionale di Fisica Nucleare, Florence (Italy); Giovannini, A. [Turin Univ. (Italy). Ist. di Fisica Teorica]|[Istituto Nazionale di Fisica Nucleare, Turin (Italy); Lupia, S. [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut
1996-10-01
Predictions of a thermodynamical model of hadron production for multiplicity distributions in e{sup +}e{sup -} annihilations at LEP and PEP-PETRA centre of mass energies are shown. The production process is described as a two-step process in which primary hadrons emitted from the thermal source decay into final observable particles. The final charged track multiplicity distributions turn out to be of negative binomial type and are in quite good agreement with experimental observations. The average number of clans calculated from fitted negative binomial coincides with the average number of primary hadrons predicted by the thermodynamical model, suggesting that clans should be identified with primary hadrons. (orig.)
Hadronic model for the non-thermal radiation from the binary system AR Scorpii
Bednarek, W.
2018-05-01
AR Scorpii is a close binary system containing a rotation powered white dwarf and a low-mass M type companion star. This system shows non-thermal emission extending up to the X-ray energy range. We consider hybrid (lepto-hadronic) and pure hadronic models for the high energy non-thermal processes in this binary system. Relativistic electrons and hadrons are assumed to be accelerated in a strongly magnetised, turbulent region formed in collision of a rotating white dwarf magnetosphere and a magnetosphere/dense atmosphere of the M-dwarf star. We propose that the non-thermal X-ray emission is produced either by the primary electrons or the secondary e± pairs from decay of charged pions created in collisions of hadrons with the companion star atmosphere. We show that the accompanying γ-ray emission from decay of neutral pions, which are produced by these same protons, is expected to be on the detectability level of the present and/or the future satellite and Cherenkov telescopes. The γ-ray observations of the binary system AR Sco should allow us to constrain the efficiency of hadron and electron acceleration and also the details of the radiation processes.
Hadron matrix elements of quark operators in the relativistic quark model
Energy Technology Data Exchange (ETDEWEB)
Bando, Masako; Toya, Mihoko [Kyoto Univ. (Japan). Dept. of Physics; Sugimoto, Hiroshi
1979-07-01
General formulae for evaluating matrix elements of two- and four-quark operators sandwiched by one-hadron states are presented on the basis of the relativistic quark model. Observed hadronic quantities are expressed in terms of those matrix elements of two- and four-quark operators. One observes various type of relativistic expression for the matrix elements which in the non-relativistic case reduce to simple expression of the so-called ''the wave function at the origin /sup +/psi(0)/sup +/''.
The calculation of multiquark hadrons by the quark model baryon, meson and multiquark states
International Nuclear Information System (INIS)
Takeuchi, Sachiko; Takizawa, Makoto; Yasui, Shigehiro
2011-01-01
The 1st new hadron summer school related with the new science field, 'the comprehensive research of new hadron states searched by variable flavor number scheme', was held on August 18-20, 2010. This report is one of the 'quark model' lectures. The chapter 1 describes following problems: 1. The background and the significance as a phenomenological theory of the constituent quark model. 2. The introduction of the quark model. 3. The summary of the properties of hadrons in which the quark model can apply to three quarks (qqq) and, one quark and antiquark (q - q) configurations, but is difficult to apply to some configurations. 4. A brief summary of exotic hadrons and recent problems. In chapter 2, the introduction and some exercises of the stochastic variational method are reported as a technique of solving spatial part of multiquark states. In the chapter 3, spins and color parts in multiquark states are calculated. The group theory is applied to calculate the eigenvalues of the Casimir operators of SU(2), SU(3) and SU(6). In the problems of being unable to apply Casimir operators, the direct matrix diagonalization method, m-scheme, is employed for interacting quarks and for the interaction involving quark mass. To find the attractive interaction in tetraquark (QQqq-bar) state is given as an exercise problem. (Y. Kazumata)
Hadron static properties in the model considering the structure of QCD vacuum
International Nuclear Information System (INIS)
Dorokhov, A.E.; Kochelev, N.I.
1987-01-01
The model taking into account the interaction of quarks with QCD vacuum fields is applied to calculate the mean-square charge radii, magnetic moments and axial-vector constants of the hadron interaction. It is shown that one-particle contributions of these characteristics describe the experimental data with 20% accuracy
International Nuclear Information System (INIS)
Mizutani, T.
2000-01-01
There were basically three theoretical projects supported by this grant: (1) Use of confined quark models to study low energy hadronic processes; (2) Production of strangeness by Electromagnetic Probes; and (3) Diffractive dissociative production of vector mesons by virtual photons on nucleons. Each of them is summarized in the paper
International Nuclear Information System (INIS)
Zeeb, G.
2006-01-01
In this thesis the thermodynamical properties of strongly interacting hadronic matter and the microscopic in-medium properties of hadrons are investigated at high temperatures and high baryonic densities within a chiral flavor-SU(3) model. The applied model is a generalized σ-ω model in mean-field approximation with baryons and mesons as effective degrees of freedom. It is built on spontaneously broken chiral symmetry and scale invariance. The phase transition behavior is systematically analyzed and is thus shown to depend significantly on the couplings of additional heavier hadronic degrees of freedom. A phase diagram in qualitative agreement with current lattice QCD (lQCD) calculations can result from an according coupling of the lowest lying baryonic decuplet to the model. Alternatively, the coupling of a heavy baryonic test-resonance is investigated, which effectively represents the spectrum of the heavy hadronic states. For a certain range of parameters one can even obtain a phase diagram in quantitative agreement with the lQCD calculations and, simultaneously, a successful description of the ground state properties of nuclear matter. It is shown that (within the model assumptions) the phase transition region is experimentally accessible for the CBM experiment at the upcoming FAIR facility at GSI Darmstadt. The chiral model is further applied to particle yield ratios measured in heavy-ion collisions from AGS, SPS and RHIC. For these investigations parameter sets with strongly differing phase diagrams due to different couplings of the baryon decuplet are used and in addition an ideal hadron gas. At the lower and mid collision energies the chiral parameter sets show an improved description as compared to the ideal hadron gas, especially for parameter sets with phase diagrams similar to the lQCD predictions. The interaction within the chiral model leads to in-medium modifications of the chemical potentials and the hadron masses. Therefore the resulting freeze
Mach-Like Structure in a Patronic-Hadronic Transport Model at RHIC Energies
International Nuclear Information System (INIS)
Ma, Y.G.; Ma, G.L.; Zhang, S.
2008-01-01
Recent RHIC experimental results indicated an exotic partonic matter may be created in central Au + Au collisions at dollars sqrt (s ( NN))dollars =200 GeV. When a parton with high transverse momentum (jet) passes through the new matter, jet will quench. The lost energy will be redistributed into the medium. Experimentally the soft scattered particles which carry the lost energy have been reconstructed via di-hadron angular correlations of charged particles and a hump structure on away side in di-hadron $ Delta phi$ correlation has been observed in central Au + Au collisions [1,2]. Some interpretations, such as Mach-cone shock wave and gluon Cherenkov-like radiation mechanism etc, have been proposed to explain the splitting behavior of the away side peaks. However, quantitative understanding of the experimental observation has yet to be established. In this work, we use a multi-phase transport (AMPT) model to make a detailed simulation for di-hadron or tri-hadron azimuthal correlation for central Au + Au collisions at dollars sqrt(s ( NN)) dollars =200 GeV. The hump structure on away side (we called Mach-like structure later) in the di-hadron and tri-hadron azimuthal correlations has been observed [3,4,5]. Furthermore, the time evolution of Mach-like structure is presented [6]. With the increasing of the lifetime of partonic matter, Mach-like structure develops by strong parton cascade process. Not only the splitting parameter but also the number of associated hadrons (dollarsN ( h) (assoc)dollars) increases with the lifetime of partonic matter and partonic interaction cross section. Both the explosion of dollarsN ( h) (assoc)dollars following the formation of Mach-like structure and the corresponding results of three-particle correlation support that a partonic Mach-like behavior can be produced by a collective coupling of partons because of the strong parton cascade mechanism. Therefore, the studies about Mach-like structure may give us some critical information
Charge distributions and correlations in fragmentation models for soft hadron collisions
International Nuclear Information System (INIS)
Wolf, E.A. de
1984-01-01
Data on charge distributions and charge correlations in pp and meson-proton interactions at PS and SPS energies are successfully compared with the Lund fragmentation model for low-psub(T) hadron collisions. It is argued that local conservation of quantum numbers and resonance production, as implemented in fragmentation models, are sufficient ingredients to explain most of the available experimental results at these energies. No necessity is found for dual-sheet contributions considered in DTU-based parton models. (orig.)
Measurement of the top-quark mass in all-hadronic decays in pp collisions at CDF II.
Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; Daronco, S; Datta, M; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; Dituro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S
2007-04-06
We present a measurement of the top-quark mass Mtop in the all-hadronic decay channel tt-->W+bW-b-->q1q2bq3q4b. The analysis is performed using 310 pb-1 of sqrt[s]=1.96 TeV pp[over ] collisions collected with the CDF II detector using a multijet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of Mtop=177.1+/-4.9(stat)+/-4.7(syst) GeV/c2.
Energy Technology Data Exchange (ETDEWEB)
Da Ronco, Saverio [Univ. of Padua (Italy)
2006-01-01
This thesis reports the reconstruction and lifetime measurement of B^{+}, B$0/atop{d}$ and B$0/atop{s}$ mesons, performed using fully reconstructed hadronic decays collected by a dedicated trigger at CDF II experiment. This dedicated trigger selects significantly displaced tracks from primary vertex of p$\\bar{p}$ collisions generated at Tevatron collider, obtaining, in this way, huge data samples enriched of long-lived particles, and is therefore suitable for reconstruction of B meson in hadronic decay modes. Due to the trigger track impact parameter selections, the proper decay time distributions of the B mesons no longer follow a simply exponential decay law. This complicates the lifetime measurement and requires a correct understanding and treatment of all the involved effects to keep systematic uncertainties under control. This thesis presents a method to extract the lifetime of B mesons in “ct- biased” samples, based on a Monte Carlo approach, to correct for the effects of the trigger and analysis selections. We present the results of this method when applied on fully re- constructed decays of B collected by CDF II in the data taking runs up to August 2004, corresponding to an integrated luminosity of about 360 pb^{-1}. The lifetimes are extracted using the decay modes B^{+} → $\\bar{D}$^{0}π^{+},B$0\\atop{d}$ → D^{-}π^{+}, B$0\\atop{d}$ → D^{-}π^{+}π^{-}π^{+}, B$0\\atop{s}$ → D$-\\atop{s}$π^{+} and B$0\\atop{s}$ → D$-\\atop{s}$ π^{+}π^{-}π^{+}(and c.c.) and performing combined mass-lifetime unbinned maximum likelihood fits.
Search for the associated production of the standard-model Higgs Boson in the all-hadronic channel.
Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Copic, K; Cordelli, M; Cortiana, G; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, S W; Leone, S; Lewis, J D; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S
2009-11-27
We report on a search for the standard-model Higgs boson in pp collisions at square root(s) = 1.96 TeV using an integrated luminosity of 2.0 fb(-1). We look for production of the Higgs boson decaying to a pair of bottom quarks in association with a vector boson V (W or Z) decaying to quarks, resulting in a four-jet final state. Two of the jets are required to have secondary vertices consistent with B-hadron decays. We set the first 95% confidence level upper limit on the VH production cross section with V(--> qq/qq')H(--> bb) decay for Higgs boson masses of 100-150 GeV/c2 using data from run II at the Fermilab Tevatron. For m(H) = 120 GeV/c2, we exclude cross sections larger than 38 times the standard-model prediction.
Photon transitions between baryons in a new hadron scheme. [Composite model, Dirac spinor
Energy Technology Data Exchange (ETDEWEB)
Sugimoto, H [Kanazawa Inst. of Tech. (Japan); Toya, M
1976-05-01
Photon transitions from the ground state baryon to the nonstrange excited one with L=0, 1 and 2 are investigated. The discussion is based on a new scheme of hadron composite model which takes account of the lower component of the Dirac spinor of constituent particles even in a hadron rest system. There appear generally four independent model amplitudes. Each process ..gamma..+p..-->..B/sub 8/* is described in terms of an individual model amplitude. This helps us to explain the characteristic features of experiment and solve the troubles found in the nonrelativistic scheme. Both magnitudes and signs of predicted amplitudes are shown to be in good agreement with experimental data. From this comparison the specific features of the model amplitudes are found. Discussion is made for higher excited baryons.
Hadronic form factor models and spectroscopy within the gauge/gravity correspondence
International Nuclear Information System (INIS)
de Teramond, Guy
2012-01-01
We show that the nonperturbative light-front dynamics of relativistic hadronic bound states has a dual semiclassical gravity description on a higher dimensional warped AdS space in the limit of zero quark masses. This mapping of AdS gravity theory to the boundary quantum field theory, quantized at fixed light-front time, allows one to establish a precise relation between holographic wave functions in AdS space and the light-front wavefunctions describing the internal structure of hadrons. The resulting AdS/QCD model gives a remarkably good accounting of the spectrum, elastic and transition form factors of the light-quark hadrons in terms of one parameter, the QCD gap scale. The light-front holographic approach described here thus provides a frame-independent first approximation to the light-front Hamiltonian problem for QCD. This article is based on lectures at the Niccolo Cabeo International School of Hadronic Physics, Ferrara, Italy, May 2011.
Hadronic form factor models and spectroscopy within the gauge/gravity correspondence
Energy Technology Data Exchange (ETDEWEB)
de Teramond, Guy F.; /Costa Rica U.; Brodsky, Stanley J.; /SLAC
2012-03-20
We show that the nonperturbative light-front dynamics of relativistic hadronic bound states has a dual semiclassical gravity description on a higher dimensional warped AdS space in the limit of zero quark masses. This mapping of AdS gravity theory to the boundary quantum field theory, quantized at fixed light-front time, allows one to establish a precise relation between holographic wave functions in AdS space and the light-front wavefunctions describing the internal structure of hadrons. The resulting AdS/QCD model gives a remarkably good accounting of the spectrum, elastic and transition form factors of the light-quark hadrons in terms of one parameter, the QCD gap scale. The light-front holographic approach described here thus provides a frame-independent first approximation to the light-front Hamiltonian problem for QCD. This article is based on lectures at the Niccolo Cabeo International School of Hadronic Physics, Ferrara, Italy, May 2011.
Examination of models of knee in primary cosmic ray spectrum using gamma-hadron families
International Nuclear Information System (INIS)
Sveshnikova, L.G.; Managadze, A.K.; Roganova, T.M.; Mukhamedshin, R.A.
2005-01-01
Four models for describing the primary cosmic radiation (PCR) spectrum are proposed/ The examination of the PCR spectra models is carried out from the viewpoint of their consistency with the data on the gamma-hadron families for the threshold energies of 100 and 500 TeV. The maximum possible contribution of the superfamilies, originating from the primary nuclei, but not from the protons, is calculated [ru
Revision of the high energy hadronic interaction models PHOJET/DPMJET-III
Fedynitch, A
2015-01-01
The high-energy hadronic interaction model DPMJET-III is responsible for simulating nuclear interactions in the particle simulation package FLUKA. On the level of individual nucleon interactions it employs PHOJET, which provides sophisticated forward physics and diffraction models. This paper summarizes some of the recent developments, in particular regarding minimum-bias physics at the LHC, which apply to DPMJET-III and PHOJET at the same time.
Test of models for soft inclusive hadronic reactions
International Nuclear Information System (INIS)
Gatignon, L.H.M.H.
1983-01-01
This thesis describes comparisons of data from soft inclusive K + and π-production with various models. The comparisons of the obtained data with models are done on the level of Lorentz-invariant longitudinal momentum distributions. For the aim of these comparisons the author has extracted the π - , π + and Ksup(n) structure functions from the raw bubble chamber measurements. Several parton models are described (quark recombination models and quark fragmentation models). For the so-called valon model, formulae are derived concerning inclusive π and K + spectra in the proton fragmentation region, and compared with experimental data. The model is generalized to determine the quark distributions in the kaon. The quark-jet oriented models are further discussed, especially the Lund model. (Auth.)
Hadronic equation of state in the statistical bootstrap model and linear graph theory
International Nuclear Information System (INIS)
Fre, P.; Page, R.
1976-01-01
Taking a statistical mechanical point og view, the statistical bootstrap model is discussed and, from a critical analysis of the bootstrap volume comcept, it is reached a physical ipothesis, which leads immediately to the hadronic equation of state provided by the bootstrap integral equation. In this context also the connection between the statistical bootstrap and the linear graph theory approach to interacting gases is analyzed
Inelasticity in hadron-nucleus collisions in the geometrical two-chain model
International Nuclear Information System (INIS)
Wibig, T.; Sobczynska, D.
1995-01-01
Two features of great importance registered in experiments on hadron-nucleus collisions are the decreased inelasticity and multiplicity in intranucleus collisions. In this paper we show that such behaviour is a natural consequence of the geometrical two-chain model of multi-particle production processes: only the forward-going chain can undergo secondary interactions in the nucleus. A quantitative comparison with the data is presented. (author)
Study of vector boson decay and determination of the Standard Model parameters at hadronic colliders
International Nuclear Information System (INIS)
Amidei, D.
1991-01-01
The power of the detectors and the datasets at hadronic colliders begins to allow measurement of the electroweak parameters with a precision that confronts the perturbative corrections to the theory. Recent measurements of M z , M w , and sin θ w by CDF and UA2 are reviewed, with some emphasis on how experimental precision is achieved, and some discussion of the import for the specifications of the Standard Model. 14 refs., 10 figs., 4 tabs
Particle ratios from AGS to RHIC in an interacting hadronic model
International Nuclear Information System (INIS)
Zschiesche, D; Zeeb, G; Paech, K; Schramm, S; Stoecker, H
2004-01-01
The measured particle ratios in central heavy-ion collisions at RHIC-BNL are investigated within a chemical and thermal equilibrium chiral SU(3) σ-ωapproach. The commonly adopted non-interacting gas calculations yield temperatures close to or above the critical temperature for the chiral phase transition, but without taking into account any interactions. In contrast, the chiral SU(3) model predicts temperature and density dependent effective hadron masses and effective chemical potentials in the medium and a transition to a chirally restored phase at high temperatures or chemical potentials. Three different parametrizations of the model, which show different types of phase transition behaviour, are investigated. We show that if a chiral phase transition occured in those collisions, 'freezing' of the relative hadron abundances in the symmetric phase is excluded by the data. Therefore, either very rapid chemical equilibration must occur in the broken phase, or the measured hadron ratios are the outcome of the dynamical symmetry breaking. Furthermore, the extracted chemical freeze-out parameters differ considerably from those obtained in simple non-interacting gas calculations. In particular, the three models yield up to 35 MeV lower temperatures than the free gas approximation. The in-medium masses turn out to differ up to 150 MeV from their vacuum values
International Nuclear Information System (INIS)
Month, M.; Weng, W.T.
1983-01-01
The objective is to investigate whether existing technology might be extrapolated to provide the conceptual framework for a major hadron-hadron collider facility for high energy physics experimentation for the remainder of this century. One contribution to this large effort is to formalize the methods and mathematical tools necessary. In this report, the main purpose is to introduce the student to basic design procedures. From these follow the fundamental characteristics of the facility: its performance capability, its size, and the nature and operating requirements on the accelerator components, and with this knowledge, we can determine the technology and resources needed to build the new facility
Born term for high-energy meson-hadron collisions from QCD and chiral quark model
International Nuclear Information System (INIS)
Ochs, W.; Shimada, T.
1988-01-01
Various experimental observations reveal a sizeable hard component in the high-energy 'soft' hadronic collisions. For primary meson beams we propose a QCD Born term which describes the dissociation of the primary meson into a quark-antiquark pair in the gluon field of the target. A pointlike effective pion-quark coupling is assumed as in the chiral quark model by Manohar and Georgi. We derive the total cross sections which for pion beams, for example, are given in terms of f π -2 and some properties of the hadronic final states. In particular, we stress the importance of studying three-jet events in meson-nucleon scattering and discuss the seagull effect. (orig.)
The magnetic model of the large hadron collider
Auchmann, B; Buzio, M; Deniau, L; Fiscarelli, L; Giovannozzi, M; Hagen, P; Lamont, M; Montenero, G; Mueller, G; Pereira, M; Redaelli, S; Remondino, V; Schmidt, F; Steinhagen, R; Strzelczyk, M; Tomas Garcia, R; Todesco, E; Delsolaro, W Venturini; Walckiers, L; Wenninger, J; Wolf, R; Zimmermann, F
2010-01-01
The beam commissioning carried out in 2009 has proved that we have a pretty good understanding of the behaviour of the relation field-current in the LHC magnets and of its reproducibility. In this paper we summarize the main issues of beam commissioning as far as the magnetic model is concerned. An outline of what can be expected in 2010, when the LHC will be pushed to 3.5 TeV, is also given.
Various decays of some hadronic systems in constituent quark models
International Nuclear Information System (INIS)
Bonnaz, R.
2001-09-01
The topic of this study is the decay of mesons in constituent quark models. Those models as well as the various quark-antiquark interaction potentials are presented. Strong decay of a meson into two or three mesons is studied in the second part. The original 3 P o model is presented as well as the research of a vertex function γ(p) depending on the momentum for the created qq-bar pair. We show that a function γ(p) of constant+Gaussian type is superior than the constant usually used. The second part is dedicated to electromagnetic transitions studied through the emission of a real or a virtual photon. In the case of real photon emission, the different approximations found in the literature are reviewed and compared to the formalism going beyond the long wave length approximation. Mixing angles are tested for some mesons. In the case of virtual photon, the expression of decay width obtained by van Royen and Weisskopf is re-demonstrated and then improved by taking into account the quark momentum distribution inside the meson. An electromagnetic dressing of quarks is introduced that improves the results. All along this study, wave functions of various sophistication degrees are used. The results of decay widths are compared to a large bulk of experimental data. (author)
Sinyukov, Yu. M.; Shapoval, V. M.
2018-06-01
The particle yields and particle number ratios in Pb+Pb collisions at the CERN Large Hadron Collider (LHC) energy √{sN N}=2.76 TeV are described within the integrated hydrokinetic model (iHKM) at two different equations of state (EoS) for quark-gluon matter and the two corresponding hadronization temperatures T =165 MeV and T =156 MeV. The role of particle interactions at the final afterburner stage of the collision in the particle production is investigated by means of comparison of the results of full iHKM simulations with those where the annihilation and other inelastic processes (except for resonance decays) are switched off after hadronization/particlization, similarly as in the thermal models. An analysis supports the picture of continuous chemical freeze-out in the sense that the corrections to the sudden chemical freeze-out results, which arise because of the inelastic reactions at the subsequent evolution times, are noticeable and improve the description of particle number ratios. An important observation is that, although the particle number ratios with switched-off inelastic reactions are quite different at different particlization temperatures which are adopted for different equations of state to reproduce experimental data, the complete iHKM calculations bring very close results in both cases.
Artificial Neural Networks For Hadron Hadron Cross-sections
International Nuclear Information System (INIS)
ELMashad, M.; ELBakry, M.Y.; Tantawy, M.; Habashy, D.M.
2011-01-01
In recent years artificial neural networks (ANN ) have emerged as a mature and viable framework with many applications in various areas. Artificial neural networks theory is sometimes used to refer to a branch of computational science that uses neural networks as models to either simulate or analyze complex phenomena and/or study the principles of operation of neural networks analytically. In this work a model of hadron- hadron collision using the ANN technique is present, the hadron- hadron based ANN model calculates the cross sections of hadron- hadron collision. The results amply demonstrate the feasibility of such new technique in extracting the collision features and prove its effectiveness
A nonabelian vortex-bond model of hadrons
International Nuclear Information System (INIS)
Patkos, A.
1976-10-01
The nature of non-Abelian theories for magnetic quark confinement is discussed. Using the internal holonomy group method the properties of infinitely long, straight, static vortices of cylindrical symmetry are investigated. For defining the conserved gauge-invariant charges the concept of ''the measuring matrices'' is used. It is shown for a general class of models that the most general vortex-like configurations can always be transformed to Abelian form. The introduction of Dirac-type monopoles and the stability problem in case of small amplitude oscillations are also discussed. (Sz. N.Z.)
Hadron component of families (exp. 'Pamir' III)
International Nuclear Information System (INIS)
Anon.
1984-01-01
Possibilities of nuclear interaction investigation at 10 15 - 10 16 ev by means of analysis of family hadron component, registered in carbon and deep lead x-ray emulsion chambers, are discussed. The paper is divided in three parts. General properties of hadron families are discribed and compared in C and Pb chambers (part I). Correlations between gamma and hadron components of families are studied in the part II. It is shown that fluctuations of energies of this component are wider than in usually used models of nuclear interactions. The ratio of single hadron flux to the flux of γ-families is connected with cross-section and energy dissipation of nuclear interactions at about 10 16 ev (part III). (author)
Applying the parton model to the fast hadrons at low p(perpendicular)
International Nuclear Information System (INIS)
Teper, M.J.
1978-03-01
The spectra of fast produced hadrons at low p (perpendicular) are discussed within the context of the parton model. Several specific models are critically considered from the experimental and theoretical point of view. Attention is focussed on the quark recombination model and improvements are suggested to overcome its problems; in particular the concept of a chameleon quark is introduced. Contamination of pseudoscalar fragments of the proton by vector meson decay is shown to be small for x > approximately 0.5. Predictions for polarised pp scattering are made. (author)
International Nuclear Information System (INIS)
Collins, P.D.B.; Martin, A.D.
1982-01-01
The mechanism of hadron scattering at high energies are reviewed in such a way as to combine the ideas of the parton model and quantum chromodynamics (QCD) with Regge theory and phenomenology. After a brief introduction to QCD and the basic features of hadron scattering data, scaling and the dimensional counting rules, the parton structure of hadrons, and the parton model for large momentum transfer processes, including scaling violations are discussed. Hadronic jets and the use of parton ideas in soft scattering processes are examined, attention being paid to Regge theory and its applications in exclusive and inclusive reactions, the relationship to parton exchange being stressed. The mechanisms of hadron production which build up cross sections, and hence the underlying Regge singularities, and the possible overlap of Regge and scaling regions are discussed. It is concluded that the key to understanding hadron reaction mechanisms seems to lie in the marriage of Regge theory with QCD. (author)
Hadron correlations from recombination
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2005-01-01
Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.
Density oscillations within hadrons
International Nuclear Information System (INIS)
Arnold, R.; Barshay, S.
1976-01-01
In models of extended hadrons, in which small bits of matter carrying charge and effective mass exist confined within a medium, oscillations in the matter density may occur. A way of investigating this possibility experimentally in high-energy hadron-hadron elastic diffraction scattering is suggested, and the effect is illustrated by examining some existing data which might be relevant to the question [fr
Deep inelastic lepton-hadron processes in gauge models with massive vector gluons
International Nuclear Information System (INIS)
Morozov, P.T.; Stamenov, D.B.
1978-01-01
Considered is a class of strong interaction models in which the interactions between coloured quarks are mediated by massive neutral vector gluons. All the vector gluons acquire masses by the Higgs mechanism. These models are not asymptotically free. The effective gauge coupling constant anti α vanishes asymptotically, and the effective quartic coupling constant anti h tends to a finite asymptotic value. The behaviour of the moments of the deep inelastic lepton-hadron structure functions is analyzed. It is shown that the Bjorken scaling is violated by powers of logarithms
International Nuclear Information System (INIS)
Jalade, P.
2005-11-01
In classical radiotherapy, the characteristics of photons interactions undergo limits for the treatment of radioresistant and not well located tumours. Pioneering treatments of patients at the Lawrence Laboratory at Berkeley has demonstrated two advantages of hadrons beams: the Relative Biologic Effect (the RBE) and the ballistic of the beams. Since 1994, the clinical centre at Chiba, has demonstrated successfully the applicability of the method. A physics group, managed by G. Kraft, at Darmstadt in Germany, has underlined the advantages of carbon beams. An European pool, called ENGIGHT (European Network for LIGHt ion Therapy) has been created in which the French ETOILE project appeared. The purpose of the thesis concerns measurements and models of 'in vitro' human cells survival. In the first part, the nowadays situation in particles interactions, tracks and cells structures and radiobiology is presented here. The second is devoted to the models based on the beam tracks and localization of the physical dose. Discussion of sensitivity to various parameters of the model has been realized with the help of numerical simulations. Finally the predictions of the improved model has been compared to experimental irradiations of human cells with argon and carbon beams of the GANIL machine. Conclusion of such study shows the performance and limits of a local model for predicting the radiobiological efficiency of light ions in hadron-therapy. (author)
International Nuclear Information System (INIS)
Dolejsi, J.; Huefner, J.
1992-01-01
The dependence of cross sections on the colour state of the colliding hadrons is investigated within the Low-Nussinov model of two-gluon exchange. The total cross sections for colour-octet hadrons are practically constant as functions of the hadronic radii, while they tend to zero when the radii of the colour-singlet hadrons approach zero. The slope parameter of the differential elastic cross sections for small momentum transfers is rather insensitive to the colour structure of the colliding hadrons. The integrated colour exchange cross section is calculated. (orig.)
High energy hadron-hadron collisions. Annual progress report
International Nuclear Information System (INIS)
Chou, T.T.
1979-03-01
Work on high energy hadron-hadron collisions in the geometrical model, performed under the DOE Contract No. EY-76-S-09-0946, is summarized. Specific items studied include the behavior of elastic hadron scatterings at super high energies and the existence of many dips, the computation of meson radii in the geometrical model, and the hadronic matter current effects in inelastic two-body collisions
Extremely high energy gamma-ray and hadron families with halo (II)
International Nuclear Information System (INIS)
Yamashita, S.; Ohsawa, A.; Chinellato, J.A.; Shibuya, E.H.
1984-01-01
The five highest energy events with the total observed energy exceeding 10 15 eV, observed by Chacaltaya emulsion chambers, are analysed and their characteristic feature are presented. Those big events are named Andromeda(halo 21,000 TeV and spots 6,140 TeV), Ursa Maior(980 TeV and 1,880 TeV), M.A.I(3,200 TeV and 1,340 TeV), M.A.II(1,300 TeV and 890 TeV) and M.A.III(5,100 TeV and 3,700 TeV). In the energy flow distributions of them, sharp peak indicating concentration of energy is found at small distance from a family center. Such concentration of energy may make a halo. If we represent the characteristic of such concentration of energy as (distance from the family center to the peak) x (energy sum within the distance), its order of magnitude becomes a few GeV.km for each big family. Comparisons are made with the simulation calculation carried out by M. Shibata. (author)
Scaling of multiplicity distribution in hadron collisions and diffractive-excitation like models
International Nuclear Information System (INIS)
Buras, A.J.; Dethlefsen, J.M.; Koba, Z.
1974-01-01
Multiplicity distribution of secondary particles in inelastic hadron collision at high energy is studied in the semiclassical impact parameter representation. The scaling function is shown to consist of two factors: one geometrical and the other dynamical. We propose a specific choice of these factors, which describe satisfactorily the elastic scattering, the ratio of elastic to total cross-section and the simple scaling behaviour of multiplicity distribution in p-p collisions. Two versions of diffractive-excitation like models (global and local excitation) are presented as interpretation of our choice of dynamical factor. (author)
Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter
Bilki, B.; Schlereth, J.; Xia, L.; Deng, Z.; Li, Y.; Wang, Y.; Yue, Q.; Yang, Z.; Eigen, G.; Mikami, Y.; Price, T.; Watson, N.K.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Carloganu, C.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Blazey, G.C.; Dyshkant, A.; Francis, K.; Lima, J.G.R.; Salcido, P.; Zutshi, V.; Boisvert, V.; Green, B.; Misiejuk, A.; Salvatore, F.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Suehara, T.; Tomita, T.; Ueno, H.; Yoshioka, T.; Apostolakis, J.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Cauwenbergh, S.; Tytgat, M.; Zaganidis, N.; Hostachy, J.Y.; Morin, L.; Gadow, K.; Göttlicher, P.; Günter, C.; Krüger, K.; Lutz, B.; Reinecke, M.; Sefkow, F.; Feege, N.; Garutti, E.; Laurien, S.; Lu, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Kaplan, A.; Norbeck, E.; Northacker, D.; Onel, Y.; Kim, E.J.; van Doren, B.; Wilson, G.W.; Wing, M.; Bobchenko, B.; Chadeeva, M.; Chistov, R.; Danilov, M.; Drutskoy, A.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Popova, E.; Gabriel, M.; Kiesling, C.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Faucci-Giannelli, M.; Fleury, J.; Frisson, T.; Kégl, B.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Pöschl, R.; Raux, L.; Rouëne, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J.-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Magniette, F.; Matthieu, A.; Mora de Freitas, P.; Videau, H.; Augustin, J.-E.; David, J.; Ghislain, P.; Lacour, D.; Lavergne, L.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Jeans, D.; Götze, M.
2015-09-11
A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the GEANT4 simulation tool kit are compared to this data. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.
Hadronization of dense partonic matter
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2006-12-15
The parton recombination model has turned out to be a valuable tool to describe hadronization in high-energy heavy-ion collisions. I review the model and revisit recent progress in our understanding of hadron correlations. I also discuss higher Fock states in the hadrons, possible violations of the elliptic flow scaling and recombination effects in more dilute systems.
International Nuclear Information System (INIS)
Fischer, J.; Kolar, P.; Kundrat, V.
1988-01-01
The proceedings contain invited lectures and papers presente at the symposium. Attention was devoted to hadron interactions a high energy in QCD, to the structure and decay of hadrons, the production of hadrons and supersymmetric particles in e + e - and ep collisions, to perturbation theory in quantum field theory, and new supersymmetric extensions of relativistic algebra. (Z.J
Relativistic form factors for hadrons with quark-model wave functions
International Nuclear Information System (INIS)
Stanley, D.P.; Robson, D.
1982-01-01
The relationship between relativistic form factors and quark-potential-model wave functions is examined using an improved version of an approach by Licht and Pagnamenta. Lorentz-contraction effects are expressed in terms of an effective hadron mass which varies as the square root of the number of quark constituents. The effective mass is calculated using the rest-frame wave functions from the mean-square momentum along the direction of the momentum transfer. Applications with the parameter-free approach are made to the elastic form factors of the pion, proton, and neutron using a Hamiltonian which simultaneously describes mesons and baryons. A comparison of the calculated radii for pions and kaons suggests that the measured kaon radius should be slightly smaller than the corresponding pion radius. The large negative squared charge radius for the neutron is partially explained via the quark model but a full description requires the inclusion of a small component of a pion ''cloud'' configuration. The problematic connection between the sizes of hadrons deduced from form factors and the ''measured'' values of average transverse momenta is reconciled in the present model
Hadronization of quark-diquark model for nucleon structure and nuclear force by path integral
International Nuclear Information System (INIS)
Nagata, Keitaro
2003-01-01
One of the central issues of the hadron physics is how to interpret the properties and the origin of nuclear force. Nuclear force is in principle the manifestation of dynamics of quarks and gluons but no trial has been successful yet in describing the nuclear force by using QCD, the fundamental theory of the strong interactions. Phenomenon related to the chiral symmetry and the spontaneous breaking of the chiral symmetry is one of the important phenomena for the understanding of hadron physics. Nambu-Jona-Lasinio (NJL) model is one of the quark system models to explain the phenomena concerning the chiral symmetry. Although the method to deduce the Lagrangian describing mesons by applying the path integral to NJL model has been well known as the bosonization, it has been difficult to extend it to baryons because baryons are three-body system. In this paper, a method is reported to deduce Lagrangian which describes baryon-meson from quark-diquark Lagrangian by assuming that baryons are the bound states of quark and diquark. (S. Funahashi)
International Nuclear Information System (INIS)
Pripstein, M.
1975-06-01
The discussion of pion charge-exchange and hadron production at large transverse momenta includes the physics motivation, the experimental method event selection criteria, results for the reaction π - p → nπ 0 (eta)
Statistical Hadronization and Holography
DEFF Research Database (Denmark)
Bechi, Jacopo
2009-01-01
In this paper we consider some issues about the statistical model of the hadronization in a holographic approach. We introduce a Rindler like horizon in the bulk and we understand the string breaking as a tunneling event under this horizon. We calculate the hadron spectrum and we get a thermal...
Test of Colour Reconnection Models using Three-Jet Events in Hadronic Z Decays
Schael, S; Brunelière, R; De Bonis, I; Décamp, D; Goy, C; Jézéquel, S; Lees, J P; Martin, F; Merle, E; Minard, M N; Pietrzyk, B; Trocmé, B; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Martínez, M; Pacheco, A; Ruiz, H; Colaleo, A; Creanza, D; De Filippis, N; 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; Barklow, T; Buchmüller, O L; Cattaneo, M; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Gianotti, F; Hansen, J B; Harvey, J; Hutchcroft, D E; Janot, P; Jost, B; Kado, M; Mato, P; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Teubert, F; Valassi, A; Videau, I; Badaud, F; Dessagne, S; Falvard, A; Fayolle, D; Gay, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Pascolo, J M; Perret, P; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Nilsson, B S; Kyriakis, A; Markou, C; Simopoulou, E; Vayaki, A; Zachariadou, K; Blondel, A; Brient, J C; Machefert, F; Rougé, A; Videau, H L; Ciulli, V; Focardi, E; Parrini, G; Antonelli, A; Antonelli, M; Bencivenni, G; Bossi, F; Capon, G; Cerutti, F; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Kennedy, J; Lynch, J G; Negus, P; O'Shea, V; Thompson, A S; Wasserbaech, S; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Stenzel, H; Tittel, K; Wunsch, M; Beuselinck, R; Cameron, W; Davies, G; Dornan, P J; Girone, M; Marinelli, N; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Pearson, M R; Robertson, N A; Smizanska, M; van der Aa, O; Delaere, C; Leibenguth, G; Lemaître, V; Blumenschein, U; Hölldorfer, F; Jakobs, K; Kayser, F; Müller, A S; Renk, B; Sander, H G; Schmeling, S; Wachsmuth, H W; Zeitnitz, C; Ziegler, T; Bonissent, A; Coyle, P; Curtil, C; Ealet, A; Fouchez, D; Payre, P; Tilquin, A; Ragusa, F; David, A; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Männer, W; Moser, H G; Settles, R; Villegas, M; Wolf, G; Boucrot, J; Callot, O; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Serin, L; Veillet, J J; Azzurri, P; Bagliesi, G; Boccali, T; Foà, L; Giammanco, A; Giassi, A; Ligabue, F; Messineo, A; Palla, F; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Spagnolo, P; Tenchini, R; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; García-Bellido, A; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Clifft, R W; Edgecock, T R; Norton, P R; Tomalin, I R; Ward, J J; Bloch-Devaux, B; Boumediene, D E; Colas, P; Fabbro, B; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Tuchming, B; Vallage, B; Litke, A M; Taylor, G; Booth, C N; Cartwright, S; Combley, F; Hodgson, P N; Lehto, M H; Thompson, L F; Böhrer, A; Brandt, S; Grupen, C; Hess, J; Ngac, A; Prange, G; Borean, C; Giannini, G; He, H; Pütz, J; Rothberg, J E; Armstrong, S R; Berkelman, K; Cranmer, K; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Pan, Y B; Von Wimmersperg-Töller, J H; Wiedenmann, W; Wu, J; Wu, S L; Wu, X; Zobernig, G; Dissertori, G
2006-01-01
Hadronic Z decays into three jets are used to test QCD models of colour reconnection (CR). A sensitive quantity is the rate of gluon jets with a gap in the particle rapidity distribution and zero jet charge. Gluon jets are identified by either energy-ordering or by tagging two b-jets. The rates predicted by two string-based tunable CR models, one implemented in JETSET (the GAL model), the other in ARIADNE, are too high and disfavoured by the data, whereas the rates from the corresponding non-CR standard versions of these generators are too low. The data can be described by the GAL model assuming a small value for the R_0 parameter in the range 0.01-0.02.
Test of colour reconnection models using three-jet events in hadronic Z decays
International Nuclear Information System (INIS)
Schael, S.; Barate, R.; Bruneliere, R.; De Bonis, I.; Decamp, D.; Goy, C.; Jezequel, S.; Lees, J.-P.; Martin, F.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Trocme, B.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Martinez, M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; De Filippis, N.; 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.; Barklow, T.; Buchmueller, O.; Cattaneo, M.; Clerbaux, B.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Hansen, J.B.; Harvey, J.; Hutchcroft, D.E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Teubert, F.; Valassi, A.; Videau, I.; Badaud, F.; Dessagne, S.; Falvard, A.; Fayolle, D.; Gay, P.; Jousset, J.; Michel, B.; Monteil, S.; Pallin, D.; Pascolo, J.M.; Perret, P.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Kraan, A.C.; Nilsson, B.S.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rouge, A.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bossi, F.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, G.P.; Passalacqua, L.; Kennedy, J.; Lynch, J.G.; Negus, P.; O'Shea, V.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E.E.; Putzer, A.; Stenzel, H.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Cameron, W.; Davies, G.; Dornan, P.J.; Girone, M.; Marinelli, N.; Nowell, J.; Rutherford, S.A.; Sedgbeer, J.K.; Thompson, J.C.; White, R.; Ghete, V.M.; Girtler, P.; Jussel, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Clarke, D.P.; Ellis, G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Smizanska, M.; van der Aa, O.; Delaere, C.; Leibenguth, G.; Lemaitre, V.; Blumenschein, U.; Hoelldorfer, F.; Jakobs, K.; Kayser, F.; Mueller, A.-S.; Renk, B.; Sander, H.-G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Bonissent, A.; Coyle, P.; Curtil, C.; Ealet, A.; Fouchez, D.; Payre, P.; Tilquin, A.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huettmann, K.; Luetjens, G.; Maenner, W.; Moser, H.-G.; Settles, R.; Villegas, M.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, P.; Jacholkowska, A.; Serin, L.; Veillet, J.-J.; Azzurri, P.; Bagliesi, G.; Boccali, T.; Foa, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Awunor, O.; Blair, G.A.; Cowan, G.; Garcia-Bellido, A.; Green, M.G.; Medcalf, T.; Misiejuk, A.; Strong, J.A.; Teixeira-Dias, P.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Ward, J.J.; Bloch-Devaux, B.; Boumediene, D.; Colas, P.; Fabbro, B.; Lancon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Tuchming, B.; Vallage, B.; Litke, A.M.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Hodgson, P.N.; Lehto, M.; Thompson, L.F.; Boehrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Ngac, A.; Prange, G.; Borean, C.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S.R.; Berkelman, K.; Cranmer, K.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara III, P.A.; Nielsen, J.; Pan, Y.B.; von Wimmersperg-Toeller, J.H.; Wiedenmann, W.; Wu, J.; Wu, S.L.; Wu, X.; Zobernig, G.
2006-01-01
Hadronic Z decays into three jets are used to test QCD models of colour reconnection (CR). A sensitive quantity is the rate of gluon jets with a gap in the particle rapidity distribution and zero jet charge. Gluon jets are identified by either energy-ordering or by tagging two b-jets. The rates predicted by two string-based tunable CR models, one implemented in JETSET (the GAL model), the other in ARIADNE, are too high and disfavoured by the data, whereas the rates from the corresponding non-CR standard versions of these generators are too low. The data can be described by the GAL model assuming a small value for the R 0 parameter in the range 0.01-0.02. (orig.)
Multiple production of hadrons at high energies in the model of quark-gluon strings
International Nuclear Information System (INIS)
Kaidalov, A.B.; Ter-Martirosyan, K.A.
1983-01-01
Multiple production of hadrons at high energies is considered in the framework of the approach based on a picture of formation and subsequent fission of the quark-gluon strings, corresponding to the Pomeron with αsub(P)(0) > 1. The topological (1/nsub(f))-expansion and the colour-tube model is used. Inclusive cross-sections are expressed in therms of the structure functions and fragmentation functions of quarks and their limiting values are in an agreement with the results of the reggeon theory. It is pointed out that an account of rapidity fluctuations of the ends of the quark-gluon strings, connected to valence or sea quarks, allows one to explain a number of characteristic features of the multiple production of hadrons. In particular the model, which takes into account multipomeron configurations, reproduces the experimentally observed rise of inclusive spectra in a central region and well describes both rapidity and multiplicity distributions of charged particles up to energies of the SPS-collider. It is shown that in this approach the KNO-scaling is only approximately satisfied and the pattern of its violation at energies √ s approximately 10 3 GeV is predicted. Inclusive spectra are investigated in the whole region 0 or approximately 0.1) Feynman scaling is violated only logarithmically and deviations from it are very rsmall at s 3 +10 4 GeV
Hadronic photon-photon interactions at high energies
International Nuclear Information System (INIS)
Engel, R.; Siegen Univ.; Ranft, J.
1996-01-01
Photon-photon collisions are investigated in the framework of the two-component Dual Parton Model. The model contains contributions from direct, resolved soft and resolved hard interactions. All free parameters of the model are determined in fits to hadron-hadron and photon-hadron cross section data. The model is shown to agree well to hadron production data from hadron-hadron and photon-hadron collisions. The multiparticle production in hadron-hadron, photon-hadron and photon-photon collisions as predicted by the model is compared. Strong differences are only found as function of the transverse momentum variable. (author)
Directory of Open Access Journals (Sweden)
Łuczak P.
2015-01-01
Full Text Available With the KASCADE-Grande Muon Tracking Detector it was possible to measure with high accuracy directions of EAS muons with energy above 0.8 GeV and up to 700 m distance from the shower centre. Reconstructed muon tracks allow investigation of muon pseudorapidity (η distributions. These distributions are nearly identical to the pseudorapidity distributions of their parent mesons produced in hadronic interactions. Comparison of the η distributions from measured and simulated showers can be used to test the quality of the high energy hadronic interaction models. The pseudorapidity distributions reflect the longitudinal development of EAS and, as such, are sensitive to the mass of the cosmic ray primary particles. With various parameters of the η distribution, obtained from the Muon Tracking Detector data, it is possible to calculate the average logarithm of mass of the primary cosmic ray particles. The results of the 〈 ln A 〉 analysis in the primary energy range 1016 eV–1017 eV with the 1st quartile and the mean value of the distributions will be presented for the QGSJet-II-2, QGSJet-II-4, EPOS 1.99 and EPOS LHC models in combination with the FLUKA model.
Directory of Open Access Journals (Sweden)
Nicholas J. Sammut
2007-08-01
Full Text Available A superconducting particle accelerator like the LHC (Large Hadron Collider at CERN, can only be controlled well if the effects of the magnetic field multipoles on the beam are compensated. The demands on a control system solely based on beam feedback may be too high for the requirements to be reached at the specified bandwidth and accuracy. Therefore, we designed a suitable field description for the LHC (FIDEL as part of the machine control baseline to act as a feed-forward magnetic field prediction system. FIDEL consists of a physical and empirical parametric field model based on magnetic measurements at warm and in cryogenic conditions. The performance of FIDEL is particularly critical at injection when the field decays, and in the initial part of the acceleration when the field snaps back. These dynamic components are both current and time dependent and are not reproducible from cycle to cycle since they also depend on the magnet powering history. In this paper a qualitative and quantitative description of the dynamic field behavior substantiated by a set of scaling laws is presented.
International Nuclear Information System (INIS)
Mukhamedshin, Rauf
2009-01-01
Simulations show that a phenomenon of coplanarity of most energetic subcores of γ-ray-hadron families found in mountain-based and stratospheric X-ray-emulsion chamber experiments requires to introduce a coplanar particle generation with large transverse momenta in hadron interactions at superhigh energies. Some physical mechanisms are considered. A phenomenological model, which makes it possible to simulate the coplanar particle generation, is presented. Different versions of this model are considered, their features are described and compared with those of models applied by the CORSIKA package. Cosmic-ray experimental data and simulated results are compared. Conclusion on features of hadron interactions at superhigh energies and some predictions with respect to LHC experiments are made. (orig.) 3
Masses of the light hadrons in the chiral and cloudy bag models
International Nuclear Information System (INIS)
Saito, Koichi.
1983-10-01
The masses of the light hadrons except for the pion are calculated in the stable chiral and cloudy bag models with the massless or massive u, d quark and pion. Two difficulties in these models, i.e. the lack of stability and the divergence of the quark self-energy, are removed by taking account of a simple non-local quark-pion interaction. The effects of the finite size of the qq-bar pion and the behavior of the quark self-energy are discussed in detail. In our calculation the bag self-energy due to the pion has an important role in the origin of the N-Δ and the Σ-Λ mass differences. The baryon octet and decuplet masses are well reproduced by the present model. (author)
International Nuclear Information System (INIS)
Dedenko, L. G.; Roganova, T. M.; Fedorova, G. F.
2015-01-01
An original method for calculating the spectrum of atmospheric muons with the aid of the CORSIKA 7.4 code package and numerical integration is proposed. The first step consists in calculating the energy distribution of muons for various fixed energies of primary-cosmic-ray particles and within several chosen hadron-interaction models included in the CORSIKA 7.4 code package. After that, the spectrum of atmospheric muons is calculated via integrating the resulting distribution densities with the chosen spectrum of primary-cosmic-ray particles. The atmospheric-muon fluxes that were calculated on the basis of the SIBYLL 2.1, QGSJET01, and QGSJET II-04 models exceed the predictions of the wellknown Gaisser approximation of this spectrum by a factor of 1.5 to 1.8 in the range of muon energies between about 10 3 and 10 4 GeV.Under the assumption that, in the region of extremely highmuon energies, a dominant contribution to the muon flux comes from one to two generations of charged π ± and K ± mesons, the production rate calculated for these mesons is overestimated by a factor of 1.3 to 1.5. This conclusion is confirmed by the results of the LHCf and TOTEM experiments
SU(2 color NJL model and EOS of quark-hadron matter at finite temperature and density
Directory of Open Access Journals (Sweden)
Weise Wolfram
2012-02-01
Full Text Available We study the NJL model with the Polyakov loop in the SU(2-color case for the EOS of quark-hadron matter at finite temperature and density. We consider the spontaneous chiral symmetry breaking and the diquark condensation together with the behavior of the Polyakov loop for the phase diagram of quark-hadron matter. We discuss the spectrum of mesons and diquark baryons (boson at finite temperature and density.We derive also the linear sigma model Lagrangian for diquark baryon and mesons.
Ambrosio, M; Aramo, C; Auriemma, G; Baldini, A; Barbarino, G C; Barish, B C; Battistoni, G; Bellotti, R; Bemporad, C; Bernardini, P; Bilokon, H; Bisi, V; Bloise, C; Bower, C; Bussino, S; Cafagna, F; Calicchio, M; Campana, D; Carboni, M; Castellano, M G; Cecchini, S; Cei, F; Chiarella, V; Coutu, S; De Benedictis, L; De Cataldo, G; Dekhissi, H; De Marzo, C; De Mitri, I; De Vincenzi, M; Di Credico, A; Erriquez, O; Favuzzi, C; Forti, C; Fusco, P; Giacomelli, G; Giannini, G; Giglietto, N; Grassi, M; Gray, L; Grillo, A; Guarino, F; Guarnaccia, P; Gustavino, C; Habig, A; Hanson, K; Hawthorne, A; Heinz, R; Iarocci, Enzo; Katsavounidis, E; Kearns, E T; Kyriazopoulou, S; Lamanna, E; Lane, C; Levin, D S; Lipari, P; Longley, N P; Longo, M J; Maaroufi, F; Mancarella, G; Mandrioli, G; Manzoor, S; Margiotta-Neri, A; Marini, A; Martello, D; Marzari-Chiesa, A; Mazziotta, M N; Mazzotta, C; Michael, D G; Mikheyev, S P; Miller, L; Monacelli, P; Montaruli, T; Monteno, M; Mufson, S L; Musser, J; Nicolò, D; Nolty, R; Okada, C; Orth, C; Osteria, G; Palamara, O; Patera, V; Patrizii, L; Pazzi, R; Peck, C W; Petrera, S; Pistilli, P; Popa, V; Rainó, A; Rastelli, A; Reynoldson, J; Ronga, F; Rubizzo, U; Sanzgiri, A; Satriano, C; Satta, L; Scapparone, E; Scholberg, K; Sciubba, A; Serra-Lugaresi, P; Severi, M; Sioli, M; Sitta, M; Spinelli, P; Spinetti, M; Spurio, M; Steinberg, R; Stone, J L; Sulak, Lawrence R; Surdo, A; Tarle, G; Togo, V; Walter, C W; Webb, R
1999-01-01
With the aim of discussing the effect of the possible sources of systematic uncertainties in simulation models, the analysis of multiple muon events from the MACRO experiment at Gran Sasso is reviewed. In particular, the predictions $9 from different currently available hadronic interaction models are compared. (9 refs).
International Nuclear Information System (INIS)
Rozanska, M.; Jezabek, M.
1991-04-01
Three version of a model with colour excitations of constituent quarks are examined using inclusive leading proton and antiproton spectra in nuclear interactions at high energies. The comparison with experimental data excludes the models in which fragmentation into leading final hadrons depends only on the colour charge of constituents in an intermediate system. (author)
International Nuclear Information System (INIS)
Ambrosio, M.; Antolini, R.; Aramo, C.; Auriemma, G.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bisi, V.; Bloise, C.; Bower, C.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Castellano, M.; Cecchini, S.; Cei, F.; Chiarella, V.; Coutu, S.; De Benedictis, L.; De Cataldo, G.; Dekhissi, H.; De Marzo, C.; De Mitri, I.; De Vincenzi, M.; Di Credico, A.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Grassi, M.; Gray, L.; Grillo, A.; Guarino, F.; Guarnaccia, P.; Gustavino, C.; Habig, A.; Hanson, K.; Hawthorne, A.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Kearns, E.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Longley, N. P.; Longo, M. J.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Manzoor, S.; Neri, A. Margiotta; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Mazzotta, C.; Michael, D. G.; Mikheyev, S.; Miller, L.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolo, D.; Nolty, R.; Okada, C.; Orth, C.; Osteria, G.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Petrera, S.; Pistilli, P.; Popa, V.; Raino, A.; Rastelli, A.; Reynoldson, J.; Ronga, F.; Rubizzo, U.; Sanzgiri, A.; Satriano, C.; Satta, L.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra-Lugaresi, P.; Severi, M.; Sioli, M.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarle, G.; Togo, V.; Walter, C. W.; Webb, R.
1999-01-01
With the aim of discussing the effect of the possible sources of systematic uncertainties in simulation models, the analysis of multiple muon events from the MACRO experiment at Gran Sasso is reviewed. In particular, the predictions from different currently available hadronic interaction models are compared
Hadronic decays of tau-leptons in the extended Nambu-Jona-Lasinio model
Energy Technology Data Exchange (ETDEWEB)
Kostunin, Dmitriy [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Kernphysik (IKP); Volkov, Mikhail; Arbuzov, Andrey [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation)
2013-07-01
Modern experiments have collected large statistics on tau-lepton decays and electron-positron annihilation into light hadrons. Therefore it is worthwhile to confront the experimental results with the corresponding theoretical predictions. The extended Nambu-Jona-Lasinio model is a good candidate for the theoretical description of these processes. Excited states of mesons in this version of the NJL model are described with the help of polynomial form-factors with minimal number of parameters. We worked out decays and cross-sections with ππ, ππ(1300), ωπ, ηπ, η'π, ηππ, η'ππ final states. Our calculations are in satisfactory agreement with the existing experimental results. Predictions for branching ratios of suppressed decays were obtained and compared with previous theoretical estimates.
Determination of freeze-out conditions from fluctuations in the Hadron Resonance Gas model
International Nuclear Information System (INIS)
Alba, P; Alberico, W; Sarti, V Mantovani; Ratti, C; Bellwied, R; Bluhm, M; Nahrgang, M
2015-01-01
Fluctuations of conserved charges measured in Heavy-Ion Collisions (HICs) received increasing attention in recent years, because they are good candidates to explore the phase diagram of QCD matter. During the last year, net-electric charge and net-proton moments of multiplicities measured at RHIC have been published by the STAR collaboration, for a range of collision energies which spans a region of the phase diagram at finite chemical potential. Here we present a new freeze-out curve obtained using the Hadron Resonance Gas (HRG) model approach to fit these experimental data. The HRG model is modified in order to have a realistic description of the HICs: kinematic cuts, resonance feed-down and resonance regeneration are taken into account. Our result is in agreement with preliminary studies by the ALICE collaboration, and is supported by a recent lattice analysis of the same quantities. (paper)
A global treatment of VMD physics up to the φ: II. τ decay and hadronic contributions to g-2
International Nuclear Information System (INIS)
Benayoun, M.; David, P.; DelBuono, L.; Leitner, O.
2010-01-01
Relying on the Hidden Local Symmetry (HLS) model equipped with a mechanism breaking the U(3)/SU(3)/SU(2) symmetries and generating a dynamical vector meson mixing, it has been shown that a global fit successfully describes the cross sections for the e + e - →π + π - , e + e - →(π 0 /η)γ and e + e - →π 0 π + π - annihilation channels. One extends this global fit in order to include also the dipion spectra from the τ decay, taking into account all reported information on their statistical and systematic errors. A model accounting for lineshape distortions of the ρ ± spectrum relative to ρ 0 is also examined when analyzing the τ data behavior within the global fit framework. One shows that a successful account for e + e - annihilation data and τ spectra can be simultaneously reached. Then, issues related with non-perturbative hadronic contributions to the muon g-2 are examined in details. It is shown that all e + e - data considered together allow for improved and motivated estimates for the a μ (π + π - ), the π + π - loop contribution to the muon g-2; for instance, integrated between 0.630 and 0.958 GeV, we find a μ (π + π - )=359.62 ±1.62 (in units of 10 -10 ), a 40% improvement of the current uncertainty. The effects of the various τ samples in the context of a global fit procedure leads to conclude that different lineshape distortions are revealed by the ALEPH, BELLE and CLEO data samples. Relying on global fits to the data quoted above, one also provides motivated estimates of the π + π - , π 0 γ, η γ and π 0 π + π - contributions to a μ up to 1 GeV with the smallest possible uncertainties. These estimates are based on various global fit configurations, each yielding a good probability. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Davier, M.; Zhang, Z. [IN2P3-CNRS et Universite Paris-Sud 11, Laboratoire de l' Accelerateur Lineaire, Orsay (France); Hoecker, A. [CERN, Geneva (Switzerland); Malaescu, B. [IN2P3-CNRS et Universites Pierre-et-Marie-Curie et Denis-Diderot, Laboratoire de Physique Nucleaire et des Hautes Energies, Paris (France)
2017-12-15
We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the Z-boson mass. We include newest e{sup +}e{sup -} → hadrons cross-section data (among others) from the BABAR and VEPP-2000 experiments. For the muon (g-2)/2 we find for the lowest-order hadronic contribution (693.1 ± 3.4) x 10{sup -10}, improving the precision of our previous evaluation by 21%. The full Standard Model prediction differs by 3.5σ from the experimental value. The five-quark hadronic contribution to α(m{sub Z}{sup 2}) is evaluated to be (276.0 ± 0.9) x 10{sup -4}. (orig.)
Phenomenology of the Higgs at the hadron colliders: from the standard model to supersymmetry
International Nuclear Information System (INIS)
Baglio, J.
2011-10-01
This thesis has been conducted in the context of one of the utmost important searches at current hadron colliders, that is the search for the Higgs boson, the remnant of the electroweak symmetry breaking. We wish to study the phenomenology of the Higgs boson in both the Standard Model (SM) framework and its minimal Supersymmetric extension (MSSM). After a review of the Standard Model in a first part and of the key reasons and ingredients for the supersymmetry in general and the MSSM in particular in a third part, we will present the calculation of the inclusive production cross sections of the Higgs boson in the main channels at the two current hadron colliders that are the Fermilab Tevatron collider and the CERN Large Hadron Collider (LHC), starting by the SM case in the second part and presenting the MSSM results, where we have 5 Higgs bosons and focusing on the two main production channels that are the gluon gluon fusion and the bottom quarks fusion, in the fourth part. The main output of this calculation is the extensive study of the various theoretical uncertainties that affect the predictions: the scale uncertainties which probe our ignorance of the higher-order terms in a fixed order perturbative calculation, the parton distribution functions (PDF) uncertainties and its related uncertainties from the value of the strong coupling constant, and the uncertainties coming from the use of an effective field theory to simplify the hard calculation. We then move on to the study of the Higgs decay branching ratios which are also affected by diverse uncertainties. We will present the combination of the production cross sections and decay branching fractions in some specific cases which will show interesting consequences on the total theoretical uncertainties. We move on to present the results confronted to experiments and show that the theoretical uncertainties have a significant impact on the inferred limits either in the SM search for the Higgs boson or on the MSSM
International Nuclear Information System (INIS)
Schumm, B.A.
1991-03-01
During the 1990 run of the Mark II at the SLC, the precision tracking system achieved a preliminary impact parameter resolution of 35.8 ± 1.3 μm for high momentum tracks, which is the quadrature sum of 25 ± 5 μm of intrinsic resolution smearing dominated by misalignments and other geometrical effects. A method is proposed by which this system can be used to measure B(Z → b rvec b/B(Z → hadrons)) with minimal systematic error. 6 refs., 3 figs
International Nuclear Information System (INIS)
Achterberg, O.; D'Agostini, G.; Apel, W.D.; Engler, J.; Fluegge, G.; Forstbauer, B.; Fries, D.C.; Fues, W.; Gamerdinger, K.; Henkes, T.; Hopp, G.; Krueger, M.; Kuester, H.; Mueller, H.; Randoll, H.; Schmidt, G.; Schneider, H.; Boer, W. de; Buschhorn, G.; Grindhammer, G.; Grosse-Wiesmann, P.; Gunderson, B.; Kiesling, C.; Kotthaus, R.; Kruse, U.; Lierl, H.; Lueers, D.; Oberlack, H.; Schacht, P.; Bonneaud, G.; Colas, P.; Cordier, A.; Davier, M.; Fournier, D.; Grivaz, J.F.; Haissinski, J.; Journe, V.; Laplanche, F.; Le Diberder, F.; Mallik, U.; Ros, E.; Veillet, J.J.; Behrend, H.J.; Fenner, H.; Schachter, M.J.; Schroeder, V.; Sindt, H.
1983-12-01
Hadronic events obtained with the CELLO detector at PETRA are compared with second order QCD predictions using different models for the fragmentation of quarks and gluons into hadrons. We find that the model dependence in the determination of the strong coupling constant persists when going from first to second order QCD calculations. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Zeeb, G.
2006-07-01
In this thesis the thermodynamical properties of strongly interacting hadronic matter and the microscopic in-medium properties of hadrons are investigated at high temperatures and high baryonic densities within a chiral flavor-SU(3) model. The applied model is a generalized {sigma}-{omega} model in mean-field approximation with baryons and mesons as effective degrees of freedom. It is built on spontaneously broken chiral symmetry and scale invariance. The phase transition behavior is systematically analyzed and is thus shown to depend significantly on the couplings of additional heavier hadronic degrees of freedom. A phase diagram in qualitative agreement with current lattice QCD (lQCD) calculations can result from an according coupling of the lowest lying baryonic decuplet to the model. Alternatively, the coupling of a heavy baryonic test-resonance is investigated, which effectively represents the spectrum of the heavy hadronic states. For a certain range of parameters one can even obtain a phase diagram in quantitative agreement with the lQCD calculations and, simultaneously, a successful description of the ground state properties of nuclear matter. It is shown that (within the model assumptions) the phase transition region is experimentally accessible for the CBM experiment at the upcoming FAIR facility at GSI Darmstadt. The chiral model is further applied to particle yield ratios measured in heavy-ion collisions from AGS, SPS and RHIC. For these investigations parameter sets with strongly differing phase diagrams due to different couplings of the baryon decuplet are used and in addition an ideal hadron gas. At the lower and mid collision energies the chiral parameter sets show an improved description as compared to the ideal hadron gas, especially for parameter sets with phase diagrams similar to the lQCD predictions. The interaction within the chiral model leads to in-medium modifications of the chemical potentials and the hadron masses. Therefore the
Rapidity distributions of hadrons in the HydHSD hybrid model
Energy Technology Data Exchange (ETDEWEB)
Khvorostukhin, A. S., E-mail: hvorost@theor.jinr.ru; Toneev, V. D. [Joint Institute for Nuclear Research (Russian Federation)
2017-03-15
A multistage hybrid model intended for describing heavy-ion interactions in the energy region of the NICA collider under construction in Dubna is proposed. The model combines the initial, fast, interaction stage described by the model of hadron string dynamics (HSD) and the subsequent evolution that the expanding system formed at the first stage experiences at the second stage and which one treats on the basis of ideal hydrodynamics; after the completion of the second stage, the particles involved may still undergo rescattering (third interaction stage). The model admits three freeze-out scenarios: isochronous, isothermal, and isoenergetic. Generally, the HydHSD hybrid model developed in the present study provides fairly good agreement with available experimental data on proton rapidity spectra. It is shown that, within this hybrid model, the two-humped structure of proton rapidity distributions can be obtained either by increasing the freeze-out temperature and energy density or by more lately going over to the hydrodynamic stage. Although the proposed hybrid model reproduces rapidity spectra of protons, it is unable to describe rapidity distributions of pions, systematically underestimating their yield. It is necessary to refine the model by including viscosity effects at the hydrodynamic stage of evolution of the system and by considering in more detail the third interaction stage.
Porter, Ryan
This thesis presents an electrical model of two pairs of interconnects of the ATLAS Phase-1 Upgrade Hadronic Endcap Front End Crate prototype baseplane. Stripline transmission lines of the baseplane are modeled using Keysight Technologies' Electromagnetic Professional's (EMPro) 3D electromagnetic simulation (Finite Element Method) and the connectors are modeled using built-in models in Keysight Technologies' Advanced Design System (ADS). The model is compared in both the time and frequency domain to measured Time Domain Reflectometer (TDR) traces and S-parameters. The S-parameters of the model are found to be within $5\\%$ of the measured S-parameters for transmission and reflection, and range from $25\\%$ below to $100\\%$ above for forward and backward crosstalk. To make comparisons with measurements, the cables used to connect the prototype HEC baseplane to the measurement system had to be included in the model. Plots of the S-parameters of a model without these cables are presented for one pair of interconne...
Event-plane dependent di-hadron correlations with harmonic vn subtraction in a hydrodynamic model
Castilho, Wagner M.; Qian, Wei-Liang; Hama, Yogiro; Kodama, Takeshi
2018-02-01
In this work, a hydrodynamic study of the di-hadron azimuthal correlations for the Au+Au collisions at 200 GeV is carried out. The correlations are evaluated using the ZYAM method for the centrality windows as well as the transverse momentum range in accordance with the existing data. Event-plane dependence of the correlation is obtained after the subtraction of contributions from the most dominant harmonic coefficients. In particular, the contribution from the triangular flow, v3, is removed from the proper correlations following the procedure implemented by the STAR collaboration. The resultant structure observed in the correlations was sometimes attributed to the mini-jet dynamics, but the present calculations show that a pure hydrodynamic model gives a reasonable agreement with the main feature of the published data. A brief discussion on the physical content of the present findings is presented.
Field and structural analysis of 56 mm aperture dipole model magnets for the Large Hadron Collider
International Nuclear Information System (INIS)
Song, Naihao; Yamamoto, Akira; Shintomi, Takakazu; Hirabayashi, Hiromi; Yamaoka, Hiroshi; Terashima, A.
1996-01-01
A new dipole model magnet design has been made with an aperture of 56 mm according to re-optimization of the accelerator design for the Large Hadron Collider (LHC) to be built at CERN. A feature of symmetric/separate collar configuration in the new design proposed by KEK has been evaluated in terms of field quality and mechanical stability according to the process of the magnet fabrication, cool-down and excitations. The analysis has been carried out by using the finite element analysis code ANSYS, in linkage of field analysis with structural analysis. Effect of the deformation, due to electromagnetic force, on the field quality has been also investigated. Results of the analysis will be presented
Model of the Phase Transition Mimicking the Pasta Phase in Cold and Dense Quark-Hadron Matter
Ayriyan, Alexander; Grigorian, Hovik
2018-02-01
A simple mixed phase model mimicking so-called "pasta" phases in the quarkhadron phase transition is developed and applied to static neutron stars for the case of DD2 type hadronic and NJL type quark matter models. The influence of the mixed phase on the mass-radius relation of the compact stars is investigated. Model parameters are chosen such that the results are in agreement with the mass-radius constraints.
Drell-Yan and diphoton production at hadron colliders and low scale gravity model
International Nuclear Information System (INIS)
Cheung, Kingman; Landsberg, Greg
2000-01-01
In the model of Arkani-Hamed, Dimopoulos, and Dvali where gravity is allowed to propagate in the extra dimensions of very large size, virtual graviton exchange between the standard model particles can give rise to signatures that can be tested in collider experiments. We study these effects in dilepton and diphoton production at hadron colliders. Specifically, we examine the double differential cross section in the invariant mass and scattering angle, which is found to be useful in separating the gravity effects from the standard model. In this work, sensitivity obtained using the double differential cross section is higher than that in previous studies based on single differential distributions. Assuming no excess of events over the standard model predictions, we obtain the following 95% confidence level lower limits on the effective Planck scale: 0.9-1.5 TeV in the Fermilab Tevatron run I, 1.3-2.5 TeV in run IIa, 1.7-3.5 TeV in run IIb, and 6.5-12.8 TeV at the CERN LHC. The range of numbers corresponds to the number of extra dimensions n=7-2. (c) 2000 The American Physical Society
High intensity hadron accelerators
International Nuclear Information System (INIS)
Teng, L.C.
1989-05-01
This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics
Studies of supersymmetry models for the ATLAS experiment at the Large Hadron Collider
Barr, A J
2002-01-01
This thesis demonstrates that supersymmetry can be discovered with the ATLAS experiment even if nature conspires to choose one of two rather difficult cases. In the first case where baryon-number is weakly violated, the lightest supersymmetric particle decays into three quarks. This leads to events with a very large multiplicity of jets which presents a difficult combinatorical problem at a hadronic collider. The distinctive property of the second class of model -- anomaly-mediation -- is the near degeneracy of the super-partners of the SU(2) weak bosons. The heavier charged wino decays producing its invisible neutral partner, the presence of which must be inferred from the apparent non-conservation of transverse momentum, as well as secondary particle(s) with low transverse momentum which must be extracted from a large background. Monte-Carlo simulations are employed to show that for the models examined not only can the distinctive signature of the model can be extracted, but that a variety of measurements (...
Signatures of Parton Exogamy in e+ e- -> W+ W- -> hadrons
Ellis, John; Geiger, Klaus
1997-01-01
We propose possible signatures of `exogamous' combinations between partons in the different W+ and W- hadron showers in e+e- -> W+W- events with purely hadronic final states. Within the space-time model for hadronic shower development that we have proposed previously, we find a possible difference of about 10 % between the mean hadronic multiplicity in such purely hadronic final states and twice the hadronic multiplicity in events in which one W decays hadronically and the other leptonically,...
AUTHOR|(CDS)2160109; Støvneng, Jon Andreas
2017-08-15
The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strength of the beam-beam interactions will be higher after the upgrade to the High-Luminosity Large Hadron Collider, and also in the next generation of machines, as the Future Circular Hadron Collider. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and drives resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. For this thesis, a new code named CABIN (Cuda-Accelerated Beam-beam Interaction) has been developed to study the limitations caused by the impact of strong beam-beam interactions. In particular, the evolution of the beam emittance and beam intensity has been monitored to study the impact quantitatively...
UCLA space-time area law model: A persuasive foundation for hadronization
International Nuclear Information System (INIS)
Abachi, S.; Buchanan, C.; Chien, A.; Chun, S.; Hartfiel, B.
2007-01-01
From the studies of rates and distributions of heavy quark (c,b) mesons we have developed additional evidence that hadron formation, at least in the simplest environment of e + e - collisions, is dominantly controlled by a space-time area law (''STAL''), an approach suggested by both non-perturbative QCD and relativistic string models. From the dynamics of heavy quarks whose classical space-time world-lines deviate significantly from the light-cone, we report the exact calculation of the relevant space-time area and the derivation of a Lorentz invariant variable, z eff , which reduces to the light-cone momentum fraction z for low mass quarks. Using z eff in the exponent of our fragmentation function in place of z, we find persuasive agreement with L=0,1 charmed and bottom meson data as well as for u,d,s L=0 states. Presuming STAL to be a valid first-order description for all these meson data, we find the scale of other possible second-order effects to be limited to ∝20% or less of the observed rates. The model favors a b-quark mass of ∝4.5 GeV. (orig.)
Modelling of flexibles for structural analysis of short straight section of Large Hadron Collider
International Nuclear Information System (INIS)
Abhay Kumar; Dutta, Subhajit; Dwivedi, Jishnu; Soni, H.C.
2003-01-01
Short Straight Section (SSS) of Large hadron Collider (LRCM) is a 8-meter long structure with a diameter of 1 meter and it houses a twin quadrupole. The cryogens are fed to the Sass through a jumper connection between Cryogenic Distribution Line (QRL) and SSS. The bus bars travel through interconnection bellows to adjoining magnets. CAT is studying the structural behavior of cold mass and the cryostat when subjected to various forces imposed on the SSS under various operating conditions of LHC machine including realignment required to compensate local sinking of the floor of the tunnel during the LHC machine's lifetime. CAT did calculation of reaction forces and moments on the Short Straight Section due to presence of jumper connection last year after the experimental verification of finite element model at CERN. Subsequently, a unified Fe model consisting of cold mass, cold feet, vacuum vessel, main vacuum vessel bellows (large sleeves), magnet interconnects, jumper connection, service module and precision motion jacks is being developed for studying the structural behaviour. (author)
Search for a $Z(4430)^{\\pm} \\to \\psi(2S)\\pi^{\\pm}$ resonance in hadron collisions at CDF II
Energy Technology Data Exchange (ETDEWEB)
Rubbo, Francesco [Univ. of Turin, Torino (Italy)
2010-01-01
The work described in this thesis is the first search for a Z^{-}(4430) resonance in hadron collisions and has been conceived, carried out and concluded entirely by the author. An ad-hoc analysis framework has been developed based on reconstruction code already consolidated in other analysis, adapted and modified for the purpose of this work. The progress of the work has been periodically presented in internal meetings of the CDF B-physics group and documented in internal notes.
Directory of Open Access Journals (Sweden)
Desiati Paolo
2013-06-01
Full Text Available The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. Using these results the differential flux and the flavor ratios of leptons were calculated. The air shower simulator CORSIKA 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high energy hadronic interaction models SIBYLL 2.1, QGSJet-01 and QGSJet-II-03. We show that the performance of the interaction models allows makes it possible to predict the spectra within experimental uncertainties, while SIBYLL generally yields a higher flux at the surface than the QGSJet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the K/π ratio within the models. The influence of the knee of cosmic rays is reflected in the secondary spectra at energies between 100 and 200 TeV. Furthermore, we could quantify systematic uncertainties of atmospheric muon- and neutrino fluxes, associated to the models of the primary cosmic ray spectrum and the interaction models. For most recent parametrizations of the cosmic ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than +15/-13% of the average flux. Uncertainties of the muon and electron neutrino fluxes can be calculated within an average error of +32/-22% and +25
International Nuclear Information System (INIS)
Kaidalov, A.B.; Volkovitsky, P.E.
1981-01-01
In the framework of the quark-gluon picture for strong interactions based on the topological expansion and the string model, the relations between t differences of hadronic cross- section are obtained. The system of equations for the contribution of secondary reggeons (rho, ω, f, A 2 and phi and f' poles) to the elastic scattering amplitudes for arbitrary hadrons is derived. It is shown that this system has a factorized solution and the secondary reggeon residues for all hadrons are expressed in terms of the universal function g(t). The model predictions are in a good agreement with experimental data [ru
Hadron Correlations and Parton Recombination
Energy Technology Data Exchange (ETDEWEB)
Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu
2007-02-15
Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.
Validation of GEANT4 Monte Carlo Models with a Highly Granular Scintillator-Steel Hadron Calorimeter
Adloff, C.; Blaising, J.J.; Drancourt, C.; Espargiliere, A.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Prast, J.; Vouters, G.; Francis, K.; Repond, J.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Buanes, T.; Eigen, G.; Mikami, Y.; Watson, N.K.; Mavromanolakis, G.; Thomson, M.A.; Ward, D.R.; Yan, W.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Uzhinskiy, V.; Benyamna, M.; Cârloganu, C.; Fehr, F.; Gay, P.; Manen, S.; Royer, L.; Blazey, G.C.; Dyshkant, A.; Lima, J.G.R.; Zutshi, V.; Hostachy, J.Y.; Morin, L.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Gottlicher, P.; Gunter, C.; Hermberg, B.; Karstensen, S.; Krivan, F.; Lucaci-Timoce, A.I.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Vargas-Trevino, A.; Feege, N.; Garutti, E.; Marchesini, I.; Ramilli, M.; Eckert, P.; Harion, T.; Kaplan, A.; Schultz-Coulon, H.Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Dauncey, P.D.; Magnan, A.M.; Bartsch, V.; Wing, M.; Salvatore, F.; Alamillo, E.Calvo; Fouz, M.C.; Puerta-Pelayo, J.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Fleury, J.; Frisson, T.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Poschl, R.; Raux, L.; Rouene, J.; Seguin-Moreau, N.; Anduze, M.; Boudry, V.; Brient, J-C.; Jeans, D.; Mora de Freitas, P.; Musat, G.; Reinhard, M.; Ruan, M.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Takeshita, T.; Uozumi, S.; Gotze, M.; Hartbrich, O.; Sauer, J.; Weber, S.; Zeitnitz, C.
2013-01-01
Calorimeters with a high granularity are a fundamental requirement of the Particle Flow paradigm. This paper focuses on the prototype of a hadron calorimeter with analog readout, consisting of thirty-eight scintillator layers alternating with steel absorber planes. The scintillator plates are finely segmented into tiles individually read out via Silicon Photomultipliers. The presented results are based on data collected with pion beams in the energy range from 8GeV to 100GeV. The fine segmentation of the sensitive layers and the high sampling frequency allow for an excellent reconstruction of the spatial development of hadronic showers. A comparison between data and Monte Carlo simulations is presented, concerning both the longitudinal and lateral development of hadronic showers and the global response of the calorimeter. The performance of several GEANT4 physics lists with respect to these observables is evaluated.
International Nuclear Information System (INIS)
Bregeon, J.
2005-09-01
GLAST is the new generation of Gamma-ray telescope and should dramatically improve our knowledge of the gamma-ray sky when it is launched on September 7. 2007. Data from the beam test that was held at GANIL with low energy ions were analyzed in order to measure the light quenching factor of CsI for all kinds of ions from proton to krypton of energy between 0 and 73 MeV per nucleon. These results have been very useful to understand the light quenching for relativistic ions that was measured during the GSI beam test. The knowledge of light quenching in GLAST CsI detectors for high energy ions is required for the on-orbit calibration with cosmic rays to succeed. Hadronic background rejection is another major issue for GLAST, thus, all the algorithms rely on the GLAST official Monte-Carlo simulation, GlastRelease. Hadronic cascade data from the GSI beam test and from another beam test held at CERN on the SPS have been used to benchmark hadronic cascade simulation within the framework of GEANT4, on which GlastRelease is based. Testing the good reproduction of simple parameters in GLAST-like calorimeters for hadronic cascades generated by 1.7 GeV, 3.4 GeV, 10 GeV and 20 GeV protons or pions led us to the conclusion that at high energy the default LHEP model is good enough, whereas at low energy the Bertini intra-nuclear cascade model should be used. (author)
Identifying Multiquark Hadrons from Heavy Ion Collisions
International Nuclear Information System (INIS)
Cho, Sungtae; Furumoto, Takenori; Yazaki, Koichi; Hyodo, Tetsuo; Jido, Daisuke; Ohnishi, Akira; Ko, Che Ming; Lee, Su Houng; Nielsen, Marina; Sekihara, Takayasu; Yasui, Shigehiro
2011-01-01
Identifying hadronic molecular states and/or hadrons with multiquark components either with or without exotic quantum numbers is a long-standing challenge in hadronic physics. We suggest that studying the production of these hadrons in relativistic heavy ion collisions offers a promising resolution to this problem as yields of exotic hadrons are expected to be strongly affected by their structures. Using the coalescence model for hadron production, we find that, compared to the case of a nonexotic hadron with normal quark numbers, the yield of an exotic hadron is typically an order of magnitude smaller when it is a compact multiquark state and a factor of 2 or more larger when it is a loosely bound hadronic molecule. We further find that some of the newly proposed heavy exotic states could be produced and realistically measured in these experiments.
Direct CP Violation in Charmless Hadronic B-Meson Decays at the PEP-II Asymmetric B-Meson Factory
Energy Technology Data Exchange (ETDEWEB)
Telnov, Alexandre Valerievich; /UC, Berkeley
2005-05-06
The study of the quark transition b {yields} s{bar s}s, which is a pure loop-level (''penguin'') process leading to several B-meson-decay final states, most notably {phi}K, is arguably the hottest topic in B-meson physics today. The reason is the sensitivity of the amplitudes and the CP-violating asymmetries in such processes to physics beyond the Standard Model. By performing these measurements, we improve our understanding of the phenomenon of combined-parity (CP) violation, which is believed to be responsible for the dominance of matter over antimatter in our Universe. Here, we present measurements of branching fractions and charge asymmetries in the decays B{sup +} {yields} {phi}K{sup +} and B{sup 0} {yields} {phi}K{sup 0} in a sample of approximately 89 million B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B-meson Factory at SLAC. We determine {Beta}(B{sup +} {yields} {phi}K{sup +}) = (10.0{sub -0.8}{sup +0.9} {+-} 0.5) x 10{sup -6} and {Beta}(B{sup 0} {yields} {phi}K{sup 0}) = (8.4{sub -1.3}{sup +1.5} {+-} 0.5) x 10{sup -6}, where the first error is statistical and the second is systematic. Additionally, we measure the CP-violating charge asymmetry {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) = 0.04 {+-} 0.09 {+-} 0.01, with a 90% confidence-level interval of [-0.10, 0.18], and set an upper limit on the CKM- and color-suppressed decay B{sup +} {yields} {phi}{pi}{sup +}, {Beta}(B{sup +} {yields} {phi}{pi}{sup +}) < 0.41 x 10{sup -6} (at the 90% confidence level). Our results are consistent with the Standard Model, which predicts {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) {approx}< 1% and {Beta}(B {yields} {phi}{tau}) << 10{sup -7}. Since many models of physics beyond the Standard Model introduce additional loop diagrams with new heavy particles and new CP-violating phases that would contribute to these decays, potentially making {Alpha}{sub CP} (B{sup {+-}} {yields} {phi
Hadron production at RHIC: recombination of quarks
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2005-01-01
We discuss quark recombination applied to the hadronization of a quark gluon plasma. It has been shown that the quark recombination model can explain essential features of hadron production measured in high energy heavy ion collisions.
Physics at hadron colliders: Experimental view
International Nuclear Information System (INIS)
Siegrist, J.L.
1987-08-01
The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs
Photon-hadron fragmentation: theoretical situation
International Nuclear Information System (INIS)
Peschanski, R.
1983-07-01
Using a selection of new experimental results models of hadronic fragmentation and their phenomenological comparison are presented. Indeed a convenient theory of hadronic fragmentation -for instance based on Q.C.D.- does not exist: low transverse momentum fragmentation involves the badly known hadronic long-range forces. Models should clarify the situation in the prospect of an eventual future theory
High energy hadron-nucleus scattering
International Nuclear Information System (INIS)
Koplik, J.; Mueller, A.H.
1975-01-01
Theoretical expectations for hadron-nucleus scattering at high energy if the basic hadron-hadron interaction is due to Regge poles and cuts arising in multiperipheral or soft field theory models are described. Experiments at Fermilab may provide a critical test of such models
Elliptic flow in a hadron-string cascade model at 130 GeV energy
Indian Academy of Sciences (India)
vectors b. The elliptic flow v2 is the anisotropy of particle emission in- and out-of reaction plane. ... However, recent observation at SPS shows similar behaviour of the elliptic flow like RHIC as a ..... hadron gas [18]. Large spatial eccentricity ε is ...
A correlated-cluster model and the ridge phenomenon in hadron–hadron collisions
Energy Technology Data Exchange (ETDEWEB)
Sanchis-Lozano, Miguel-Angel, E-mail: Miguel.Angel.Sanchis@ific.uv.es [Instituto de Física Corpuscular (IFIC) and Departamento de Física Teórica, Centro Mixto Universitat de València-CSIC, Dr. Moliner 50, E-46100 Burjassot, Valencia (Spain); Sarkisyan-Grinbaum, Edward, E-mail: sedward@cern.ch [Experimental Physics Department, CERN, 1211 Geneva 23 (Switzerland); Department of Physics, The University of Texas at Arlington, Arlington, TX 76019 (United States)
2017-03-10
A study of the near-side ridge phenomenon in hadron–hadron collisions based on a cluster picture of multiparticle production is presented. The near-side ridge effect is shown to have a natural explanation in this context provided that clusters are produced in a correlated manner in the collision transverse plane.
Valence and non-valence quark distribution function of hadrons in the val on model
International Nuclear Information System (INIS)
Khorramian, A.N.; Arash, F.
2000-01-01
We calculate the par tonic structure of constitute quark in the next-to-leading order. The structure of any hadron can be obtained thereafter using a convolution method. Such a procedure is used to generate the structure function of proton and pion in Next- to- leading order
Testing hadronic interaction models using a highly granular silicon-tungsten calorimeter
Czech Academy of Sciences Publication Activity Database
Bilki, B.; Repond, J.; Schlereth, J.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Richard; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav
2015-01-01
Roč. 794, Sep (2015), s. 240-254 ISSN 0168-9002 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : electromagnetic silicon tungsten calorimeter * highly granular detectors * hadronic showers * data and simulations Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.200, year: 2015
International Nuclear Information System (INIS)
Ilgenfritz, E.M.; Kripfganz, J.; Moehring, H.J.
1977-01-01
The analytical treatment of hadronic decay cascades within the framework of the statistical bootstrap model is demonstrated on the basis of a simple variant. Selected problems for a more comprehensive formulation of the model such as angular momentum conservation, quantum statistical effects, and the immediate applicability to particle production processes at high energies are discussed in detail
Current Status of Exotic Hadrons
International Nuclear Information System (INIS)
Saeed, M.A.; Ahmed, Maqsood; Fazal-e-Aleem
2005-01-01
Physics of exotic hadrons is in the limelight these days. The models for these baryons are discussed as well as their production and decay processes and methods of their identification. The results of recent experiments in this field are presented, in which some unusual states are observed. These states are candidates for exotic hadrons
International Nuclear Information System (INIS)
Ramanathan, R.; Singh, S.S.; Jha, A.K.; Gupta, K.K.
2011-01-01
We study the effect of finite chemical potential for the QGP constituents in the Ramanathan et al. statistical model. While the earlier computations using this model with vanishing chemical potentials indicated a weakly first order phase transition for the system in the vicinity of 170 MeV, the introduction of finite values for the chemical potentials of the constituents makes the transition a smooth roll over of the phases, while allowing fireball formation with radius of a few 'fermi' to take place. This seems to be in conformity with the latest consensus on the nature of the QGP-Hadron phase transition. (author)
Model independent particle mass measurements in missing energy events at hadron colliders
Park, Myeonghun
2011-12-01
This dissertation describes several new kinematic methods to measure the masses of new particles in events with missing transverse energy at hadron colliders. Each method relies on the measurement of some feature (a peak or an endpoint) in the distribution of a suitable kinematic variable. The first method makes use of the "Gator" variable s min , whose peak provides a global and fully inclusive measure of the production scale of the new particles. In the early stage of the LHC, this variable can be used both as an estimator and a discriminator for new physics over the standard model backgrounds. The next method studies the invariant mass distributions of the visible decay products from a cascade decay chain and the shapes and endpoints of those distributions. Given a sufficient number of endpoint measurements, one could in principle attempt to invert and solve for the mass spectrum. However, the non-linear character of the relevant coupled quadratic equations often leads to multiple solutions. In addition, there is a combinatorial ambiguity related to the ordering of the decay products from the cascade decay chain. We propose a new set of invariant mass variables which are less sensitive to these problems. We demonstrate how the new particle mass spectrum can be extracted from the measurement of their kinematic endpoints. The remaining methods described in the dissertation are based on "transverse" invariant mass variables like the "Cambridge" transverse mass MT2, the "Sheffield" contrasverse mass MCT and their corresponding one-dimensional projections MT2⊥, M T2||, MCT⊥ , and MCT|| with respect to the upstream transverse momentum U⃗T . The main advantage of all those methods is that they can be applied to very short (single-stage) decay topologies, as well as to a subsystem of the observed event. The methods can also be generalized to the case of non-identical missing particles, as demonstrated in Chapter 7. A complete set of analytical results for the
International Nuclear Information System (INIS)
Behrend, H.J.; Chen, C.; Fenner, H.; Schachter, M.J.; Schroeder, V.; Sindt, H.; D'Agostini, G.; Apel, W.D.; Banerjee, S.; Bodenkamp, J.; Chrobaczek, D.; Engler, J.; Fluegge, G.; Fries, D.C.; Fues, W.; Gamerdinger, K.; Hopp, G.; Kuester, H.; Mueller, H.; Randoll, H.; Schmidt, G.; Schneider, H.; Boer, W. de; Buschhorn, G.; Grindhammer, G.; Grosse-Wiesmann, P.; Gunderson, B.; Kiesling, C.; Kotthaus, R.; Kruse, U.; Lierl, H.; Lueers, D.; Oberlack, H.; Schacht, P.; Colas, P.; Cordier, A.; Davier, M.; Fournier, D.; Grivaz, J.F.; Haissinski, J.; Journe, V.; Klarsfeld, A.; Laplanche, F.; Le Diberder, F.; Mallik, U.; Veillet, J.J.; Field, J.H.; George, R.; Goldberg, M.; Grossetete, B.; Hamon, O.; Kapusta, F.; Kovacs, F.; London, G.; Poggioli, L.; Rivoal, M.; Aleksan, R.; Bouchez, J.; Carnesecchi, G.; Cozzika, G.; Ducros, Y.; Gaidot, A.; Jadach, S.; Lavagne, Y.; Pamela, J.; Pansart, J.P.; Pierre, F.
1983-01-01
Hadronic events obtained with the CELLO detector at PETRA were compared with first-order QCD predictions using two different models for the fragmentation of quarks and gluons, the Hoyer model and the Lund model. Both models are in reasonable agreement with the data, although they do not completely reproduce the details of many distributions. Several methods have been applied to determine the strong coupling constant αsub(s). Although within one model the value of αsub(s) varies by 20% among the different methods, the values determined using the Lund model are 30% or more larger (depending on the method used) than the values determined with the Hoyer model. Our results using the Hoyer model are in agreement with previous results based on this approach. (orig.)
International Nuclear Information System (INIS)
Chela-Flores, J.
1981-08-01
A many-body approach to hadron structure is presented, in which we consider two parton species: spin-0 (b-partons), and spin-1/2 (f-partons). We extend a boson and a fermion pairing scheme for the b-, and f-partons respectively, into a Yang-Mills gauge theory. The main feature of this theory is that the gauge field is not identified with the usual gluon field variable in QCD. We study the confinement problem of the hadron constituents, and obtain, for low temperatures, partons that are confined by energy gaps. As the critical temperatures for the corresponding phase transitions are approached, the energy gap gradually disappears, and confinement is lost. The theory goes beyond the non-relativistic harmonic oscillator quark model, in the sense of giving physical reasons why a non-relativistic approximation is adequate in describing the internal dynamics of hadron structure. (author)
International Nuclear Information System (INIS)
Anon.
1986-01-01
The European Hadron Facility (EHF) is a project for particle and nuclear physics in the 1990s which would consist of a fast cycling high intensity proton synchrotron of about 30 GeV primary energy and providing a varied spectrum of intense high quality secondary beams (polarized protons, pions, muons, kaons, antiprotons, neutrinos). The physics case of this project has been studied over the last two years by a European group of particle and nuclear physicists (EHF Study Group), whilst the conceptual design for the accelerator complex was worked out (and is still being worked on) by an international group of machine experts (EHF Design Study Group). Both aspects have been discussed in recent years in a series of working parties, topical seminars, and workshops held in Freiburg, Trieste, Heidelberg, Karlsruhe, Les Rasses and Villigen. This long series of meetings culminated in the International Conference on a European Hadron Facility held in Mainz from 10-14 March
The quark-recombination model and correlations between hard and soft hadronic processes
International Nuclear Information System (INIS)
Ranft, J.
1978-07-01
Proceeding from the fact that quark and gluon recombination models make definite predictions for correlations between hard and soft processes, the following experiments are briefly discussed: (i) correlations between deep inelastic antineutrino-proton scattering and particle production in the proton fragmentation region, (ii) correlations between massive lepton pairs and particles produced in the fragmentation regions, and (iii) correlations between large transverse momentum particles and leading protons. In order to present the large transverse momentum - leading proton correlation, a divided correlation function similar to that used for studying short-range correlations of low transverse momentum particles is defined
Aspects of hadronic B decays in and beyond the standard model
Energy Technology Data Exchange (ETDEWEB)
Vernazza, Leonardo
2009-10-16
In this thesis we address various issues of hadronic B decays, in the Standard Model and beyond. Concerning the first aspect, we focus on the problem of understanding better low energy strong interactions in these decays. We consider in particular B decays into a charmonium state and a light meson. We develop a complete treatment of low energy QCD interaction in the context of QCD factorization, treating the charmonia as nonrelativistic bound states. This allows us to demonstrate that, in the heavy-quark limit, a perturbative treatment of these decays is possible, even in case of decays into P-waves, which were found to be non-factorizing in previous studies. We achieve this, including in the analysis the bound state scales of charmonium, which in turn requires to consider charmonium production through colour-octet operators. Although there are very large uncertainties, we find reasonable parameter choices, where the main features of the data - large corrections to (naive) factorization and suppression of the {chi}{sub c2} and h{sub c} final states - are reproduced though the suppression of {chi}{sub c2} is not as strong as seen in the data. Our results also provide an example, where an endpoint divergence in hard spectator-scattering factorizes and is absorbed into colour-octet operator matrix elements. The second part of the thesis is devoted to a series of analyses of non-leptonic B decays in extensions of the Standard Model. The aim of these studies is twofold: on one hand we are interested in testing the sensitivity of these decays to new physics; on the other hand, we look for actual discrepancies between theory predictions and experimental results, trying to explain them in the context of a new physics model. Concerning the first aspect, we consider two well-motivated new physics scenarios, in which large deviations from the Standard Model are expected, i.e. the MSSM with large tan {beta}, and a supersymmetric GUT in which the large neutrino mixing angles
The UCLA hadronization model and Pt correlation study at √s = 29 GeV
International Nuclear Information System (INIS)
Chun, Sebong.
1989-01-01
With only longitudinal phase space, a linear confining quark potential, and Clebsch-Gordon coefficients, the authors demonstrate remarkable agreement with a large body of data. This involves only two parameters of a modified Lund symmetric fragmentation function a, b and three coherent lengths: the number of hadrons over which the transverse momentum P t is required to be compensated, the degree of the spin correlation between a diquark and its partner anti-diquark in baryon and anti-baryon production, and the degree of suppression of successive mesons created between a baryon and anti-baryon (which comes from the uncertainty principle). These coherent lengths have a common fundamental characteristic, namely, the propagation length of information along the chain of produced hadrons. As a separate effort to probe the propagation length of P t , we studied the correlations in momentum transverse to the event jet-axis for neighboring particles close in rapidity, which reflect the tendency of back-to-back production of the hadron pairs. He found indications of interesting correlations, but that a larger data sample is needed for definitive understanding of the area
Energy Technology Data Exchange (ETDEWEB)
Pondrom, L.
1991-10-03
An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.
International Nuclear Information System (INIS)
Pondrom, L.
1991-01-01
An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs
Kalmakhelidze, M; Svanidze, M
2002-01-01
Primary Cosmic Rays Nuclear Composition was investigated in energy region 10 sup 1 sup 5 -10 sup 1 sup 6 eV. The study is based on comparison of gamma hadron families observed by Pamir and Pamir-Chacaltaya collaborations with those generated by means of quasi-scaling model MC0 at different nuclear compositions. It was shown that all characteristics of the observed families (including their intensity) are in very good agreement with properties of simulated events MC0 at normal composition and are in disagreement at heavy dominant compositions
Energy Technology Data Exchange (ETDEWEB)
Ye, Wanyu [State Univ. of New York (SUNY), Stony Brook, NY (United States)
2012-12-01
The Standard Model has been a successful theory in various aspects. It predicted and led to discovery of many new particles, including the Higgs boson recently found, the last missing piece of the Standard Model. The Higgs mechanism allows the vector bosons and fermions to be massive via the electroweak symmetry breaking. This dissertation presents the search of the Standard Model Higgs through the decay products: one muon, one hadronically decaying tau, and two or more jets using the full 9.7 fb$^{-1}$ of Tevatron collider Run II data set collected in the Dzero detector at Fermilab. The main production channels are gluon-gluon fusion, vector boson fusion, and Higgs production associated with a $W/Z$ boson. No evidence of the Standard Model Higgs boson is observed in these channels with hypothesized Higgs mass between 105 GeV and 150 GeV, but the data do not exclude it either. We set the upper limits on the ratio of the 95% CL exclusion to the SM Higgs cross section. Combining with other analyses in Tevatron, the Higgs mass is ruled out at 95 % confidence level between 147 and 180 GeV, and a 2.9 $\\sigma$ excess of events indicates a Higgs boson possibly lies in the mass range from 115 to 140 GeV.
International Nuclear Information System (INIS)
Krivoruchenko, M.I.
1985-01-01
In chiral bag model an expression is obtained for the quark wave functions with account of color and pion interaction of quarks. The quadrupole moments of nonstrange hadrons are calculated. Quadrupole moment of nucleon isobar is found to be Q(Δ)=-6.3x10 -28 esub(Δ)(cm)sup(2). Fredictions of the chiral bag model are in strong disagreement with the non-relativistic quark model
River water quality modelling: II
DEFF Research Database (Denmark)
Shanahan, P.; Henze, Mogens; Koncsos, L.
1998-01-01
The U.S. EPA QUAL2E model is currently the standard for river water quality modelling. While QUAL2E is adequate for the regulatory situation for which it was developed (the U.S. wasteload allocation process), there is a need for a more comprehensive framework for research and teaching. Moreover......, QUAL2E and similar models do not address a number of practical problems such as stormwater-flow events, nonpoint source pollution, and transient streamflow. Limitations in model formulation affect the ability to close mass balances, to represent sessile bacteria and other benthic processes......, and to achieve robust model calibration. Mass balance problems arise from failure to account for mass in the sediment as well as in the water column and due to the fundamental imprecision of BOD as a state variable. (C) 1998 IAWQ Published by Elsevier Science Ltd. All rights reserved....
Quark confinement and hadronic interactions
International Nuclear Information System (INIS)
Lenz, F.
1985-01-01
With the possibility for 'exact' calculations within the framework of a fundamental theory, QCD, the role of models in strong interaction physics is changing radically. The relevance of detailed numerical model studies is diminishing with the development of those exact, numerical approaches to QCD. On the other hand, the insight gained from such purely numerical studies is necessarily limited and must be complemented by the more qualitative but also more intuitive insight gained from model studies. In particular, the subject of hadron-hadron interactions requires model studies to relate the wide variety of strong interaction physics to the fundamental properties of strong interaction physics. The author reports on such model studies of the hadron-hadron interaction
Centrality Dependence of Hadron Multiplicities in Nuclear Collisions in the Dual Parton Model
Capella, A
2001-01-01
We show that, even in purely soft processes, the hadronic multiplicity in nucleus-nucleus interactions contains a term that scales with the number of binary collisions. In the absence of shadowing corrections, this term dominates at mid rapidities and high energies. Shadowing corrections are calculated as a function of impact parameter and the centrality dependence of mid-rapidity multiplicities is determined. The multiplicity per participant increases with centrality with a rate that increases between SPS and RHIC energies, in agreement with experiment.
Directory of Open Access Journals (Sweden)
P. Ferracin
2000-12-01
Full Text Available Estimates of random field-shape errors induced by cable mispositioning in superconducting magnets are presented and specific applications to the Large Hadron Collider (LHC main dipoles and quadrupoles are extensively discussed. Numerical simulations obtained with Monte Carlo methods are compared to analytic estimates and are used to interpret the experimental data for the LHC dipole and quadrupole prototypes. The proposed approach can predict the effect of magnet tolerances on geometric components of random field-shape errors, and it is a useful tool to monitor the obtained tolerances during magnet production.
International Nuclear Information System (INIS)
Schneider, J.L.
1993-12-01
The hadronic final state in deep inelastic e - P collisions has been studied with the 1992 data from the ZEUS detector at HERA. The hadronic final state is described by event topology variables like thrust and sphericity and also by variables like multiplicity and transverse momentum. These quantities require the reconstruction of the particle four moments which are calculated from calorimeter cell clusters (condensates). A detailed Monte-Carlo comparison between final state particles and condensates is presented. ZEUS data and model predictions are compared in the γ * P system. Good agreement between data and models is found in the x-Feynman and transverse momentum spectra and in the seagull plot. Mean thrust and sphericity are measured as functions of the invariant mass W of the hadronic final state. They significantly deviate from the model predictions, as do the mean multiplicities, which exceed the model predictions by about 1 unit. (orig.)
Hadron matrix elements of quark operators in the relativistic quark model, 2. Model calculation
Energy Technology Data Exchange (ETDEWEB)
Arisue, H; Bando, M; Toya, M [Kyoto Univ. (Japan). Dept. of Physics; Sugimoto, H
1979-11-01
Phenomenological studies of the matrix elements of two- and four-quark operators are made on the basis of relativistic independent quark model for typical three cases of the potentials: rigid wall, linearly rising and Coulomb-like potentials. The values of the matrix elements of two-quark operators are relatively well reproduced in each case, but those of four-quark operators prove to be too small in the independent particle treatment. It is suggested that the short-range two-quark correlations must be taken into account in order to improve the values of the matrix elements of the four-quark operators.
International Nuclear Information System (INIS)
Sundman, S.
1981-01-01
The static particle model of Part I requires creation of ether proportional to the energy of the particle. It is shown that this ether creation leads to gravitation and a forever expanding universe in agreement with the large-number hypothesis. The age, mass and size of the universe are calculated from atomic constants and G. The model predicts scale-invariance with different scales for gravitational matter, nucleons and electrons. This leads to a fine structure constant decreasing very slowly with time. For each scale there is a different type of dynamic balance governing the expansion of the universe. The model indicates that the universe was initially densely packed with (tau) leptons. It suggests a program for calculating the gravitational constant and the muon-electron mass ratio from other universal constants. Tentative numerological derivation gives these quantities with a higher accuracy than has been achieved experimentally. (Auth.)
Topological objects in hadron physics
International Nuclear Information System (INIS)
Rho, M.
1988-01-01
The notion of topological objects in hadronic physics is discussed, with emphasis on the role of the Wess-Zumino term and induced transmutation of quantum numbers in chiral bag models. Some applications to nuclear systems are given
Bilki, Burak
2018-03-01
The Particle Flow Algorithms attempt to measure each particle in a hadronic jet individually, using the detector providing the best energy/momentum resolution. Therefore, the spatial segmentation of the calorimeter plays a crucial role. In this context, the CALICE Collaboration developed the Digital Hadron Calorimeter. The Digital Hadron Calorimeter uses Resistive Plate Chambers as active media and has a 1-bit resolution (digital) readout of 1 × 1 cm2 pads. The calorimeter was tested with steel and tungsten absorber structures, as well as with no absorber structure, at the Fermilab and CERN test beam facilities over several years. In addition to conventional calorimetric measurements, the Digital Hadron Calorimeter offers detailed measurements of event shapes, rigorous tests of simulation models and various tools for improved performance due to its very high spatial granularity. Here we report on the results from the analysis of pion and positron events. Results of comparisons with the Monte Carlo simulations are also discussed. The analysis demonstrates the unique utilization of detailed event topologies.
International Nuclear Information System (INIS)
Phalen, Daniel J.; Thomas, Brooks; Wells, James D.
2007-01-01
For a standard model Higgs boson with mass between 115 GeV and 150 GeV, the two-photon decay mode is important for discovery at the Large Hadron Collider (LHC). We describe the interactions of a light Higgs boson in a more model-independent fashion and consider the parameter space where there is no two-photon decay mode. We argue from generalities that analysis of the tth discovery mode outside its normal thought of range of applicability is especially needed under these circumstances. We demonstrate the general conclusion with a specific example of parameters of a type I two-Higgs doublet theory, motivated by ideas in strongly coupled model building. We then specify a complete set of branching fractions and discuss the implications for the LHC
Supo Thermal Model Development II
Energy Technology Data Exchange (ETDEWEB)
Wass, Alexander Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-07-14
This report describes the continuation of the Computational Fluid Dynamics (CFD) model of the Supo cooling system described in the report, Supo Thermal Model Development1, by Cynthia Buechler. The goal for this report is to estimate the natural convection heat transfer coefficient (HTC) of the system using the CFD results and to compare those results to remaining past operational data. Also, the correlation for determining radiolytic gas bubble size is reevaluated using the larger simulation sample size. The background, solution vessel geometry, mesh, material properties, and boundary conditions are developed in the same manner as the previous report. Although, the material properties and boundary conditions are determined using the appropriate experiment results for each individual power level.
Keil, Eberhard
1998-01-01
Plans for future hadron colliders are presented, and accelerator physics and engineering aspects common to these machines are discussed. The Tevatron is presented first, starting with a summary of the achievements in Run IB which finished in 1995, followed by performance predictions for Run II which will start in 1999, and the TeV33 project, aiming for a peak luminosity $L ~ 1 (nbs)^-1$. The next machine is the Large Hadron Collider LHC at CERN, planned to come into operation in 2005. The last set of machines are Very Large Hadron Colliders which might be constructed after the LHC. Three variants are presented: Two machines with a beam energy of 50 TeV, and dipole fields of 1.8 and 12.6 T in the arcs, and a machine with 100 TeV and 12 T. The discussion of accelerator physics aspects includes the beam-beam effect, bunch spacing and parasitic collisions, and the crossing angle. The discussion of the engineering aspects covers synchrotron radiation and stored energy in the beams, the power in the debris of the p...
Electromagnetic polarizabilities of hadrons
International Nuclear Information System (INIS)
Friar, J.L.
1988-01-01
Electromagnetic polarizabilities of hadrons are reviewed, after a discussion of classical analogues. Differences between relativistic and non-relativistic approaches can lead to conflicts with conventional nuclear physics sum rules and calculational techniques. The nucleon polarizabilities are discussed in the context of the non-relativistic valence quark model, which provides a good qualitative description. The recently measured pion polarizabilities are discussed in the context of chiral symmetry and quark-loop models. 58 refs., 5 figs
Energy Technology Data Exchange (ETDEWEB)
Hicks, R.G.
1978-01-01
An experiment was performed to study muon-proton scattering at an incident energy of 225 GeV and a total effective flux of 4.3 x 10/sup 10/ muons. This experiment is able to detect charged particles in coincidence with the scattered muon in the forward hemisphere, and results are reported for the neutral strange particles K/sub s//sup 0/ and ..lambda../sup 0/ decaying into two charged particles. Within experimental limits the masses and lifetimes of these particles are consistent with previous measurements. The distribution of hadrons produced in muon scattering is determined, measuring momentum components parallel and transverse to the virtual photon direction, and these distributions are compared to other high energy experiments involving the scattering of pions, protons, and neutrinos from protons. Structure functions for hadron production and particle ratios are calculated. No azimuthal dependence is observed, and lambda production does not appear to be polarized. The physical significance of the results is discussed within the framework of the quark-parton model. 29 references.
Nuclei, hadrons, and elementary particles
International Nuclear Information System (INIS)
Bopp, F.W.
1989-01-01
This book is a short introduction to the physics of the nuclei, hadrons, and elementary particles for students of physics. Important facts and model imaginations on the structure, the decay, and the scattering of nuclei, the 'zoology' of the hadrons and basic facts of hadronic scattering processes, a short introduction to quantum electrodynamics and quantum chromodynamics and the most important processes of lepton and parton physics, as well as the current-current approach of weak interactions and the Glashow-Weinberg-Salam theory are presented. (orig.) With 153 figs., 10 tabs [de
Hadron collider physics 2005. Proceedings
International Nuclear Information System (INIS)
Campanelli, M.; Clark, A.; Wu, X.
2006-01-01
The Hadron Collider Physics Symposia (HCP) are a new series of conferences that follow the merger of the Hadron Collider Conferences with the LHC Symposia series, with the goal of maximizing the shared experience of the Tevatron and LHC communities. This book gathers the proceedings of the first symposium, HCP2005, and reviews the state of the art in the key physics directions of experimental hadron collider research: - QCD physics - precision electroweak physics - c-, b-, and t-quark physics - physics beyond the Standard Model - heavy ion physics The present volume will serve as a reference for everyone working in the field of accelerator-based high-energy physics. (orig.)
Physics at Future Hadron Colliders
Baur, U.; Parsons, J.; Albrow, M.; Denisov, D.; Han, T.; Kotwal, A.; Olness, F.; Qian, J.; Belyaev, S.; Bosman, M.; Brooijmans, G.; Gaines, I.; Godfrey, S.; Hansen, J.B.; Hauser, J.; Heintz, U.; Hinchliffe, I.; Kao, C.; Landsberg, G.; Maltoni, F.; Oleari, C.; Pagliarone, C.; Paige, F.; Plehn, T.; Rainwater, D.; Reina, L.; Rizzo, T.; Su, S.; Tait, T.; Wackeroth, D.; Vataga, E.; Zeppenfeld, D.
2001-01-01
We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.
International Nuclear Information System (INIS)
Ferreira, P.L.
1984-01-01
An overview of the current phenomenological models of hadron structure, whose theoretical basis is the Quantum Chromodynamics (QCD), is presented. A short introduction to the QCD permits to focalize the relevant properties which are attached to those models. Following, bag-like models (in particular, MIT bag and chiral extensions) and potential-like models among them the Karl and Isgur non-relativistic model and a semi-relativistic model, free of the Klein paradox, with equal scalar-vetorial mixture of confinement potential are shortly studied. Enphasis is given to the baryons, treated, basically, as three-quarks systems. (L.C.) [pt
Charge asymmetry in e+e- → γ + hadrons: New tests of the quark-parton model and fractional charge
International Nuclear Information System (INIS)
Brodsky, S.J.; Carlson, C.E.; Suaya, R.
1976-01-01
We consider the process e + e - → γ + h + X, where h is a hadron and γ is a hard photon, and show how it can be used to test the quark-parton model. Detailed formulas are given for the cross sections, which in the quark-parton model are products of cross sections for e + e - → γμanti μ and quark breakup functions. We focus on the asymmetry between h and h-bar production, and display sum rules and ratio tests which measure the quark charge, the quark Compton amplitude, and the large-x behavior of the quark breakup function. The asymmetry is calculated for the muon case, and is about 100% for the forward direction
Multi-hadron final states in RPV supersymmetric models with extra matter
International Nuclear Information System (INIS)
Asano, Masaki; Sakurai, Kazuki; Yanagida, Tsutomu T.
2014-01-01
The gluino mass has been constrained by various search channels at the LHC experiments and the recent analyses are even sensitive to the cases where gluinos decay to quarks at the end of the decay chains through the baryonic RPV operator. We argue that introduction of extra matter, which is partly motivated by cancelling anomalies of discrete R symmetry, may help to relax the gluino mass limit when the RPV hadronic gluino decays are considered. In the scenarios where the extra matter states appear in the gluino decay chains, the number of decay products increases and each jet becomes soft, making it difficult to distinguish the signal from backgrounds. We investigate the sensitivity of existing analyses to such scenarios and demonstrate that the gluino mass limit can be relaxed if the mass spectrum reconciles the sensitivities of high p T jet searches and large jet multiplicity searches
Multi-hadron final states in RPV supersymmetric models with extra matter
Directory of Open Access Journals (Sweden)
Masaki Asano
2014-09-01
Full Text Available The gluino mass has been constrained by various search channels at the LHC experiments and the recent analyses are even sensitive to the cases where gluinos decay to quarks at the end of the decay chains through the baryonic RPV operator. We argue that introduction of extra matter, which is partly motivated by cancelling anomalies of discrete R symmetry, may help to relax the gluino mass limit when the RPV hadronic gluino decays are considered. In the scenarios where the extra matter states appear in the gluino decay chains, the number of decay products increases and each jet becomes soft, making it difficult to distinguish the signal from backgrounds. We investigate the sensitivity of existing analyses to such scenarios and demonstrate that the gluino mass limit can be relaxed if the mass spectrum reconciles the sensitivities of high pT jet searches and large jet multiplicity searches.
Duru, Firdevs
2007-01-01
This thesis consists of two main parts: R&D; studies done on the Compact Muon Solenoid (CMS) Hadronic Calorimeter (HCAL) and physics simulations on the Higgs boson for a Minimal Supersymmetric Standard Model (MSSM) and a Standard Model (SM) channel. In the first part, the air core light guides used in the read-out system of the Hadronic Forward (HF) calorimeter and the reflective materials used in them are studied. Then, tests and simulations were performed to find the most efficient way to collect Cerenkov light from the quartz plates, which are proposed as a substitute for the scintillator tiles in the Hadronic Endcap (HE) calorimeter due to radiation damage problems. In the second part physics simulations and their results are presented. The MSSM channel H/A[arrow right]ττ [arrow right]l l v v v v is studied to investigate the jet and missing transverse energy (MET) reconstruction of the CMS detector. The effects of the jet and MET corrections on the Higgs boson mass reconstruction are investigated. ...
HERWIG for Hadron-Hadron physics
International Nuclear Information System (INIS)
Seymour, M.H.
1993-05-01
HERWIG is a general-purpose particle physics event generator, which includes the simulation of any combination of hard lepton, hadron or photon scattering and soft hadron-hadron collisions in one package. It uses the parton-shower approach for initial-state and final-state QCD radiation, including colour coherence effects and azimuthal correlations both within and between jets. This article describes HERWIG version 5.6, and gives a brief review of the physics underlying HERWIG, with particular emphasis on hadron-hadron collisions. Details are given of the input and control parameters used by the program
Supersymmetry at hadron supercolliders
International Nuclear Information System (INIS)
Dzialo, D.L.
1989-01-01
At the next generation of hadron supercolliders, the proposed US Superconducting Supercollider (SSC) and the European Large Hadron Collider (LHC), protons will be collided at such high energy to allow the creation of new particles with masses greater those that have been previously created in the laboratory. One of the most important questions to be resolved at these accelerators is whether or not any supersymmetric extension of the Standard Model is manifest below the TeV scale. It is expected that the strongly-interacting supersymmetric particles, the gluinos and squarks, will be pair-produced in the most abundance there. Light gluinos primarily decay into quarks and the lightest supersymmetric particle, which is assumed to escape detection; this gives the classic supersymmetric signature of events with large missing momentum. It is known, however, that for gluinos of masses larger than just 100 GeV this process is no longer the preferred gluino decay channel. New signals must therefore be sought to either detect these particles, or to set meaningful lower mass limits. It is in this work that such new detection strategies for supersymmetry at hadron supercolliders are proposed. Gluino and squark production rates and decay channels are studied in a model-independent fashion over the entire theoretical mass range of interest. New experimental signatures are proposed and compared with sources of background over a wide region of the parameter space that characterizes different supersymmetric models
Hadron seagulls and parton jets
International Nuclear Information System (INIS)
Satz, H.; Zarmi, Y.
1976-01-01
For the lepton production of hadrons in the current fragmentation region it was recently shown that the two-level partonic picture leads to a broadening of the average transverse momentum of the observed secondaries. This ''seagull'' effect is well known for hadron-hadron interactions. In the note it is considered the possibility that parton arguments can explain it here as well and it is discussed what information on the constituent structure of hadrons can be obtained through an investigation of the seagull effect from such a point of view. It is shown that a non trivial seagull effect is a consequence of a simple two step production mechanism and the parton model predicts significant differences between baryon, meson and virtual-photon fragmentation seagull
Fixed target hadron production measurements
Panman, J
2009-01-01
The knowledge of light hadron production cross-sections in proton-nucleus interactions is an important prerequisite to the analysis of a wide variety of experiments. One of the important limiting factors for the precision of accelerator based and atmospheric neutrino oscillation experiments is the uncertainty in the composition and spectrum of the neutrino flux. Cosmic-ray experiments detecting extensive air-showers can greatly improve their ability to interpret the data when precise hadron production spectra are available over a large range of energies. Dedicated hadron production experiments have been taking data recently and are now publishing their results. Other experiments have just started their data-taking and plan to supply measurements which can significantly extend the kinematic range in which data will be available. Early measurements at the LHC can extend this range to much higher energies than available up to now. Recent results will be shown and compared with hadronic production models. An outl...
Studies of the ATLAS hadronic Calorimeter response to different particles at Test Beams
Zakareishvili, Tamar; The ATLAS collaboration
2018-01-01
The Large Hadron Collider (LHC) Phase II upgrade aims to increase the accelerator luminosity by a factor of 5-10. Due to the expected higher radiation levels and the aging of the current electronics, a new readout system of the ATLAS experiment hadronic calorimeter (TileCal) is needed. A prototype of the upgrade TileCal electronics has been tested using the beam from the Super Proton Synchrotron (SPS) accelerator at CERN. Data were collected with beams of muons, electrons and hadrons at various incident energies and impact angles. The muons data allow to study the dependence of the response on the incident point and angle in the cell. The electron data are used to determine the linearity of the electron energy measurement. The hadron data will allow to tune the calorimeter response to pions and kaons modelling to improve the reconstruction of the jet energies. The results of the ongoing data analysis are discussed in the presentation.
Hadron correlations from recombination and fragmentation
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2005-04-01
We review the formalism of quark recombination applied to the hadronization of a quark-gluon plasma. Evidence in favour of the quark recombination model is outlined. Recent work on parton correlations, leading to detectable correlations between hadrons, is discussed. Hot spots from completely quenched jets are a likely source of such correlations which appear to be jet like. It will be discussed how such a picture compares with measurement of associated hadron yields at RHIC.
International Nuclear Information System (INIS)
Cohen-Tannoudji, G.
1989-01-01
This series of lectures is devoted to review ot he connections between QCD and string theories. One reviews the phenomenological models leading to string pictures in non perturbative QCD and the string effects, related to soft gluon coherence, which arise in perturbative QCD. One tries to build a string theory which goes to QCD at the zero slope limit. A specific model, based on superstring theories is shown to agree with QCD four point amplitudes at the Born approximation and with one loop corrections. One shows how this approach can provide a theoretical framework to account for the phenomenological property of parton-hadron duality.(author)
Phenomenological studies of hadronic collisions
International Nuclear Information System (INIS)
van Zijl, M.
1987-04-01
Several aspects of hadronic collisions are studied in a phenomenological framework. A Monte Carlo model for initial state parton showers, using a backwards evolution scheme, is presented. Comparisons with experimental data and analytical calculations are made. The consequence of using different fragmentation model on the determination of α s is also investigated. It is found that the different fragmentation models lead to the reconstruction of significantly α s values. Finally the possibility of having several independent parton-parton interactions in a hadron-hadron collision is studied. A model is developed, which takes into account the effects of variable impact parameters. This is implemented in a Monte Carlo computer program and extensive comparisons with experimental data are carried out. There is clear evidence in favour of multiple interactions with variable impact parameters. (author)
Hadronic degrees of freedom in relativistic heavy ion collisions
International Nuclear Information System (INIS)
Otuka, Naohiko; Ohnishi, Akira
2001-01-01
The observation of temperature and transverse expansion velocity between BNL-AGS and CERN-SPS suggests the change of property of hadronic matter. In order to study the origin of the fact, it is important to check whether or not pure hadronic scenarios are excluded. We have discussed the temperature and transverse expansion in relativistic heavy-ion collisions using pure hadronic cascade model, HANDEL. We conclude the hadronic matter in AGS energies are understandable in the frame of the hadronic cascade model if we care how much hadronic degrees of freedom are counted. (author)
Polarization effects in hadron fragmentation
International Nuclear Information System (INIS)
Lednicky, R.
1984-01-01
Hadron polarization (spin alignment) and polarization asymmetry are discussed in terms of the quark recombination model with the spin-orbit interaction taken into account. It is shown that predictions of this model are at least in qualitative agreement with experimental data. Various polarization mechanisms in terms of this model and the possibility of their checking are also discussed
Non-Equilibrium Heavy Flavored Hadron Yields from Chemical Equilibrium Strangeness-Rich QGP
Kuznetsova, Inga; Rafelski, Johann
2008-01-01
The yields of heavy flavored hadrons emitted from strangeness-rich QGP are evaluated within chemical non-equilibrium statistical hadronization model, conserving strangeness, charm, and entropy yields at hadronization.
Parton-hadron cascade approach at SPS and RHIC
Energy Technology Data Exchange (ETDEWEB)
Nara, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
1998-07-01
A parton-hadron cascade model which is the extension of hadronic cascade model incorporating hard partonic scattering based on HIJING is presented to describe the space-time evolution of parton/hadron system produced by ultra-relativistic nuclear collisions. Hadron yield, baryon stopping and transverse momentum distribution are calculated and compared with HIJING and VNI. Baryon density, energy density and temperature for RHIC are calculated within this model. (author)
Supersymmetric hadronic mechanics and procedures for isosupersymmetrization
International Nuclear Information System (INIS)
Ntibashirakandi, L.; Callebaut, D.K.
1994-01-01
In this paper the authors present the Lie-Santilli lifting of Witten's one-dimensional supersymmetric quantum mechanical model within the context of supersymmetric hadronic mechanics and extended it to three dimensions. They show that the model describes the motion of a spin one-half particle in a central isosuperpotential. Choosing this isosuperpotential within the specific isosupersymmetrization procedure, their theory produces the model of hadronic harmonic oscillator plus isotopic spin-orbit couplings. They finally indicate that their model describes a particle under conventional potentials plus nonlocal-nonhamiltonian corrections expected in deep penetrations of the wavepackets. As such, the model appears to be significant for the recently proposed chemical synthesis of unstable hadrons via lighter hadrons, which is prohibited by quantum mechanics, but permitted by the covering hadronic mechanics. 16 refs
Composite hadrons and relativistic nuclei
International Nuclear Information System (INIS)
Blankenbecler, R.
1978-01-01
Lectures are presented describing a model of hadronic scattering at large momentum transfer, either transverse or longitudinal. This model emphasizes in this regime the importance of forces involving the interchange of constituents of the hadrons, hence its name, the constituent interchange model CIM. The CIM is a rearrangement of standard perturbation theory to take into account the fact that the binding force is very strong in color singlet states (singlet dominance). The hard scattering expansion, incoherence problems, nuclear wave functions and counting rules, interaction between nuclei, pion and proton yields and form factors, structure functions and nonscaling, massive lepton pairs, hadrons at large transverse momentum, and quark-quark scattering are treated. 49 references
Systematic approach to inclusive lepton pair production in hadronic collisions
International Nuclear Information System (INIS)
Lam, C.S.; Tung, W.
1978-01-01
Strong-interaction dynamics as probed by lepton pair production in hadronic collisions is naturally separated from kinematics by using suitably defined structure functions. In the first part of this paper, general properties of invariant structure functions and a variety of ''helicity'' structure functions for this process are studied, and their use discussed. An exact parallelism to the case of deep-inelastic lepton-hadron scattering is set up. In the second part, a series of parton-model relations between the structure functions, reflecting the basic Drell-Yan on-shell quark-antiquark annihilation picture (but independent of details of parton distributions), is derived. These relations serve the dual purposes of (i) supplementing the model-independent structure-function formalism and rendering it useful for analyzing data of limited scope initially, and (ii) providing unambiguous tests of various aspects of the underlying quark-parton model when more detailed data become available
Meißner, Ulf-G.
2004-01-01
The status of hadron physics at the end of the HADRON07 Conference is reviewed. The latest results presented at the conference, as well as those important developments in the field which were not represented, are included.
QCD in hadron-hadron collisions
International Nuclear Information System (INIS)
Albrow, M.
1997-03-01
Quantum Chromodynamics provides a good description of many aspects of high energy hadron-hadron collisions, and this will be described, along with some aspects that are not yet understood in QCD. Topics include high E T jet production, direct photon, W, Z and heavy flavor production, rapidity gaps and hard diffraction
Very high multiplicity hadron processes
International Nuclear Information System (INIS)
Mandzhavidze, I.; Sisakyan, A.
2000-01-01
The paper contains a description of a first attempt to understand the extremely inelastic high energy hadron collisions, when the multiplicity of produced hadrons considerably exceeds its mean value. Problems with existing model predictions are discussed. The real-time finite-temperature S-matrix theory is built to have a possibility to find model-free predictions. This allows one to include the statistical effects into consideration and build the phenomenology. The questions to experiment are formulated at the very end of the paper
CMS Central Hadron Calorimeter
Budd, Howard S.
2001-01-01
We present a description of the CMS central hadron calorimeter. We describe the production of the 1996 CMS hadron testbeam module. We show the results of the quality control tests of the testbeam module. We present some results of the 1995 CMS hadron testbeam.
Problems of hadron electrodynamics
International Nuclear Information System (INIS)
Rekalo, M.P.
1989-01-01
Certain directions of hadron electrodynamics referring to testing symmetry properties relatively to C-, P- and T-transformations; determination of fundamental electromagnetic characteristics of hadrons as well as to clarifying the dynamics of electromagnetic processes in which hadrons participate are analyzed briefly. 52 refs
Narison, Stephan
2007-07-01
About Stephan Narison; Outline of the book; Preface; Acknowledgements; Part I. General Introduction: 1. A short flash on particle physics; 2. The pre-QCD era; 3. The QCD story; 4. Field theory ingredients; Part II. QCD Gauge Theory: 5. Lagrangian and gauge invariance; 6. Quantization using path integral; 7. QCD and its global invariance; Part III. MS scheme for QCD and QED: Introduction; 8. Dimensional regularization; 9. The MS renormalization scheme; 10. Renormalization of operators using the background field method; 11. The renormalization group; 12. Other renormalization schemes; 13. MS scheme for QED; 14. High-precision low-energy QED tests; Part IV. Deep Inelastic Scattering at Hadron Colliders: 15. OPE for deep inelastic scattering; 16. Unpolarized lepton-hadron scattering; 17. The Altarelli-Parisi equation; 18. More on unpolarized deep inelastic scatterings; 19. Polarized deep-inelastic processes; 20. Drell-Yan process; 21. One 'prompt photon' inclusive production; Part V. Hard Processes in e+e- Collisions: Introduction; 22. One hadron inclusive production; 23. gg scatterings and the 'spin' of the photon; 24. QCD jets; 25. Total inclusive hadron productions; Part VI. Summary of QCD Tests and as Measurements; Part VII. Power Corrections in QCD: 26. Introduction; 27. The SVZ expansion; 28. Technologies for evaluating Wilson coefficients; 29. Renormalons; 30. Beyond the SVZ expansion; Part VIII. QCD Two-Point Functions: 31. References guide to original works; 32. (Pseudo)scalar correlators; 33. (Axial-)vector two-point functions; 34. Tensor-quark correlator; 35. Baryonic correlators; 36. Four-quark correlators; 37. Gluonia correlators; 38. Hybrid correlators; 39. Correlators in x-space; Part IX. QCD Non-Perturbative Methods: 40. Introduction; 41. Lattice gauge theory; 42. Chiral perturbation theory; 43. Models of the QCD effective action; 44. Heavy quark effective theory; 45. Potential approaches to quarkonia; 46. On monopole and confinement; Part X. QCD
Heavy quark correlations in hadronic collisions
International Nuclear Information System (INIS)
Mangano, M.L.; Ridolfi, G.
1992-01-01
The study of heavy quark production at hadron colliders will provide important tests and measurements within and possibly beyond the Standard Model. The results of a recent calculation of heavy quark hadronic production correlation properties at the full next-to-leading order (NLO) in perturbative QCD are presented. These properties are important for several applications. (R.P.) 8 refs.; 3 figs
Correlations in hadron-nucleus collisions
International Nuclear Information System (INIS)
Wosiek, B.
1976-09-01
The correlations between the particles produced in interactions of hadrons with emulsion nuclei were investigated. The data are in qualitative agreement with the models which describe the interactions with nuclei as subsequent collisions of the fast part of excited hadronic matter inside the nucleus. (author)
Strange baryon production in Z hadronic decays
Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Allport, P P; Almehed, S; Alvsvaag, S J; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Anykeyev, V B; Apel, W D; Arnoud, Y; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barate, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bocci, V; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brunet, J M; Brückman, P; Bugge, L; Buran, T; Buys, A; Bärring, O; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carrilho, P; Carroll, L; Caso, Carlo; Cassio, V; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chikilev, O G; Chliapnikov, P V; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; D'Almagne, B; Da Silva, W; Dahl-Jensen, Erik; Dahm, J; Dam, M; Damgaard, G; Daum, A; Dauncey, P D; Davenport, Martyn; De Angelis, A; De Boeck, H; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Defoix, C; Della Ricca, G; Delpierre, P A; Demaria, N; Di Ciaccio, Lucia; Dijkstra, H; Djama, F; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Dupont, F; Dönszelmann, M; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Föth, H; Fürstenau, H; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gillespie, D; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Gracco, Valerio; Grard, F; Graziani, E; Grosdidier, G; Gunnarsson, P; Guy, J; Guz, Yu; Górski, M; Günther, M; Haedinger, U; Hahn, F; Hahn, M; Hahn, S; Haider, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Ioannou, P; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Joram, Christian; Juillot, P; Jönsson, L B; Jönsson, P E; Kaiser, M; Kalmus, George Ernest; Kapusta, F; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Kokkinias, P; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Królikowski, J; Kubinec, P; Kucewicz, W; Kurvinen, K L; Kuznetsov, O; Köhne, J H; Köne, B; La Vaissière, C de; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lokajícek, M; Loken, J G; Loukas, D; Lutz, P; Lyons, L; López, J M; López-Aguera, M A; López-Fernandez, A; Lörstad, B; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martí i García, S; Martínez-Rivero, C; Martínez-Vidal, F; Maréchal, B; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Meroni, C; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Monge, M R; Morettini, P; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Mönig, K; Møller, R; Müller, H; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Némécek, S; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Pape, L; Parodi, F; Passeri, A; Pegoraro, M; Pennanen, J; Peralta, L; Pernegger, H; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ruiz, A; Rídky, J; Rückstuhl, W; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sannino, M; Schneider, H; Schyns, M A E; Sciolla, G; Scuri, F; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stepaniak, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Stäck, H; Szczekowski, M; Szeptycka, M; Sánchez, J; Tabarelli de Fatis, T; Tavernet, J P; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tuuva, T; Tyapkin, I A; Tyndel, M; Tzamarias, S; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van Doninck, W K; Van Eldik, J; Van der Velde, C; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Voutilainen, M; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Wehr, A; Weierstall, M; Weilhammer, Peter; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Wormser, G; Woschnagg, K; Yip, K; Yu, L; Yushchenko, O P; Zach, F; Zacharatou-Jarlskog, C; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zhigunov, V P; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G; de Boer, Wim; van Apeldoorn, G W; van Dam, P; Åsman, B; Österberg, K; Überschär, B; Überschär, S
1995-01-01
A study of the production of strange octet and decuplet baryons in hadronic decays of the Z recorded by the DELPHI detector at LEP is presented. This includes the first measurement of the \\Sigma^\\pm average multiplicity. The total and differential cross sections, the event topology and the baryon-antibaryon correlations are compared with current hadronization models.
International Nuclear Information System (INIS)
Igi, K.
1979-01-01
This paper is related to mini-rapporteur talk on baryonium spectroscopy. First of all, the models of baryonium, namely the diquark model, the string picture, the linear baryonium and the bag model, are described. All of these models so far discussed are highly suggestive. In this paper, discussions are confined to the spectroscopy of the string and the bag models. Because of the color degree of freedom, the bag model has mock diquonium and mock mesonium besides true baryonium. It might be possible that the string model takes into account only a part of them. The constraints among baryonium, baryon and boson trajectories using duality and unitarity were proposed as a guide for classifying various spectra. Inequalities were derived as the modest and reliable constraints on baryonium intercepts from baryon and boson intercepts by imposing unitarity and Regge behaviors on scattering amplitudes. As a consequence of residue factorization and duality, the baryonium slopes were derived. The spin of S (1936) was also obtained. The baryonium containing s or c quarks can also be studied. Topics such as the EXD patterns of baryons, linear baryons, linear Regge trajectories for all Q-anti Q families, and the Al and two Q mesons, are presented in this paper. Comments on di-baryon are described. (Kato, T.)
Reply to ''Test of a chromomagnetic model for hadron mass differences''
International Nuclear Information System (INIS)
Silvestre-Brac, B.
1993-01-01
The shortcomings of the chromomagnetic model, as raised by Lichtenberg and Roncaglia, are analyzed and relativized. The chromomagnetic model fails to provide correct binding energies for multiquark systems and even to predict qualitatively stability of such objects. However, it is simple and physically sound so as to discriminate among the most favorable structures. As such, its use for a systematic study of a whole set of candidates is highly recommended in a first step
International Nuclear Information System (INIS)
Olsen, S.L.
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 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 mesons and the predicted QCD-exotic states. (author)
International Nuclear Information System (INIS)
Malaescu, B.
2010-01-01
The scope of this thesis is to obtain and use accurate data on e + e - annihilation into hadrons at energies of 1 GeV of magnitude order. These data represent a very valuable input for Standard Model tests involving vacuum polarization, such as the comparison of the muon magnetic moment to theory, and for QCD tests and applications. The different parts of this thesis describe four aspects of my work in this context. First, the measurements of cross sections as a function of energy necessitate the unfolding of data spectra from detector effects. I have proposed a new iterative unfolding method for experimental data, with improved capabilities compared to existing tools. Secondly, the experimental core of this thesis is a study of the process e + e - → K + K - from threshold to 5 GeV using the initial state radiation (ISR) method (through the measurement of e + e - → K + K - γ) with the BABAR detector. All relevant efficiencies are measured with experimental data and the absolute normalization comes from the simultaneously measured μμγ process. I have performed the full analysis which achieves a systematic uncertainty of 0.7% on the dominant φ resonance. Results on e + e - → π + π - from threshold to 3 GeV are also presented. Thirdly, a comparison based on 2 different ways to get a prediction of the muon magnetic moment: the Standard Model and the hadronic tau decay, shows an interesting hint for new physics effects (3.2 σ effect). Fourthly, QCD sum rules are powerful tools for obtaining precise information on QCD parameters, such as the strong coupling α S . I have worked on experimental data concerning the spectral functions from τ decays measured by ALEPH. I have discussed to some detail the perturbative QCD prediction obtained with two different methods: fixed-order perturbation theory (FOPT) and contour-improved perturbative theory (CIPT). The corresponding theoretical uncertainties have been studied at the τ and Z mass scales. The CIPT method
Chargino and neutralino production at the Large Hadron Collider in left-right supersymmetric models
Alloul, Adam; Fuks, Benjamin; Rausch de Traubenberg, Michel
2013-10-04
We present a complete and extensive analysis of associated chargino and neutralino production in the framework of a supersymmetric theory augmented by left-right symmetry. This model provides additional gaugino and higgsino states in both the neutral and charged sectors, thus potentially enhancing new physics signals at the LHC. For a choice of benchmark scenarios, we calculate cross sections for 7, 8 and 14 TeV. We then simulate events expected to be produced at the LHC, and classify them according to the number of leptons in the final state. We devise methods to reduce the background and compare the signals with consistently simulated events for the Minimal Supersymmetric Standard Model. We pinpoint promising scenarios where left-right symmetric supersymmetric signals can be distinguished both from background and from the Minimal Supersymmetric Standard Model events.
Measurement of the Z-boson branching fraction into hadrons containing bottom quarks
International Nuclear Information System (INIS)
Kral, J.F.
1990-09-01
We use the Mark II detector to study Z decays into bottom quark-anti-quark pairs, leading to the production of bottom hadrons. The Z bosons are formed in e + e - annihilation at the SLC at center-of-mass energies between 89 and 93 GeV. We identify events containing semileptonic decays of bottom hadrons by detecting isolated leptons, i.e leptons with high transverse momenta relative to the nearest hadronic jet. Using isolated electrons and muons, we measure the B-hadron semileptonic branching ratio times the fraction of hadronic Z decays which contain bottom hadrons, B(B → X ell ν)·Γ(Z → b bar b)/Γ(Z → had) = 0.025 -0.009 +0.100 ± 0.005, where we have listed the statistical errors followed by the systematic error. Assuming B(B → X(ell)ν) = 11% ± 1%, we measure Γ(Z → b bar b)/Γ(Z → had) = 0.23 -0.09 +0.11 , in good agreement with the standard-model prediction of 0.22. We find Γ(Z → b bar b) = 0.40 -0.16 +0.19 GeV. 83 refs., 34 figs., 19 tabs
Validation of GEANT4 Monte Carlo models with a highly granular scintillator-steel hadron calorimeter
Czech Academy of Sciences Publication Activity Database
Adloff, C.; Blaha, J.; Blaising, J.J.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Denis; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav
2013-01-01
Roč. 8, Jul (2013), s. 1-33 ISSN 1748-0221 Institutional support: RVO:68378271 Keywords : interaction of radiation with matter * calorimeter methods * detector modelling and simulations Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.526, year: 2013
Some new aspects of the unitary and analytic VMD model for electromagnetic structure of hadrons
International Nuclear Information System (INIS)
Dubnickova, A.Z.; Dubnicka, S.
1991-01-01
Recent J/φ→π + π - data analyzed along with all existing pion form factor data by means of the unitary and analytic vector dominance model manifest a strong evidence of the third excited state of the ρ(770) meson with resonance parameters m ρ ''' =2169±46 MeV and Γ ρ ''' =319±136 MeV. A simultaneous analysis of all reliable proton and neutron form factor data in the space-like region along with data on the total cross section of electron-positron annihilation into a proton-antiproton pair by the same model predicts an unexpected inequality σ tot (e e- +→nn-bar)>>σ tot (e + e - →pp-bar) just above the nucleon-antinucleon threshold and also surprisingly large one-photon electromagnetic corrections to the strong J/φ→pp-bar and J/φ→nn-bar decay amplitudes. 21 refs.; 5 figs.; 1 tab
Remarks on electromagnetic form factors of hadrons in the quark model
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Vainshtein, A.I.; Zakharov, V.I.
1977-01-01
Relations between the transversal and longitudinal parts of elastic and quasielastic form factors are studied within the quark model. It is shown that for an even number of the constituent quarks the longitudinal part dominates while for an odd number the transversal part is the largest one. Consequences form this result are considered for deuteron form factor and for matrix elements of the electromagnetic transitions between π, rho, A 1 mesons
Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan
2015-01-01
After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.
GUT models at current and future hadron colliders and implications to dark matter searches
Arcadi, Giorgio; Lindner, Manfred; Mambrini, Yann; Pierre, Mathias; Queiroz, Farinaldo S.
2017-08-01
Grand Unified Theories (GUT) offer an elegant and unified description of electromagnetic, weak and strong interactions at high energy scales. A phenomenological and exciting possibility to grasp GUT is to search for TeV scale observables arising from Abelian groups embedded in GUT constructions. That said, we use dilepton data (ee and μμ) that has been proven to be a golden channel for a wide variety of new phenomena expected in theories beyond the Standard Model to probe GUT-inspired models. Since heavy dilepton resonances feature high signal selection efficiencies and relatively well-understood backgrounds, stringent and reliable bounds can be placed on the mass of the Z‧ gauge boson arising in such theories. In this work, we obtain 95% C.L. limits on the Z‧ mass for several GUT-models using current and future proton-proton colliders with √{ s} = 13 TeV , 33 TeV ,and 100 TeV, and put them into perspective with dark matter searches in light of the next generation of direct detection experiments.
GUT models at current and future hadron colliders and implications to dark matter searches
Directory of Open Access Journals (Sweden)
Giorgio Arcadi
2017-08-01
Full Text Available Grand Unified Theories (GUT offer an elegant and unified description of electromagnetic, weak and strong interactions at high energy scales. A phenomenological and exciting possibility to grasp GUT is to search for TeV scale observables arising from Abelian groups embedded in GUT constructions. That said, we use dilepton data (ee and μμ that has been proven to be a golden channel for a wide variety of new phenomena expected in theories beyond the Standard Model to probe GUT-inspired models. Since heavy dilepton resonances feature high signal selection efficiencies and relatively well-understood backgrounds, stringent and reliable bounds can be placed on the mass of the Z′ gauge boson arising in such theories. In this work, we obtain 95% C.L. limits on the Z′ mass for several GUT-models using current and future proton–proton colliders with s=13 TeV,33 TeV,and100 TeV, and put them into perspective with dark matter searches in light of the next generation of direct detection experiments.
Hadron--hadron reactions, high multiplicity
International Nuclear Information System (INIS)
Diebold, R.
1978-09-01
A coverage of results on high energy and high multiplicity hadron reactions, charm searches and related topics, ultrahigh energy events and exotic phenomena (cosmic rays), and the nuclear effects in high energy collisions and related topics is discussed. 67 references
Gluonic excitations in hadronic spectroscopy
International Nuclear Information System (INIS)
Close, F.E.
1983-09-01
Theoretical expectations are described for new forms of hadronic matter containing gluons as excitable degrees of freedom. Particular attention is paid to hybrid states containing both quarks and gluons. Recent work on the spectroscopy of hybrid mesons and hybrid baryons is reviewed. Comparisons of bag model, lattice QCD and QCD sum rule predictions are made and some confrontation with data attempted. (author)
Energy Technology Data Exchange (ETDEWEB)
Moch, S
2008-02-15
We review the status of QCD at hadron colliders with emphasis on precision predictions and the latest theoretical developments for cross sections calculations to higher orders. We include an overview of our current information on parton distributions and discuss various Standard Model reactions such as W{sup {+-}}/Z-boson, Higgs boson or top quark production. (orig.)
International Nuclear Information System (INIS)
Moch, S.
2008-02-01
We review the status of QCD at hadron colliders with emphasis on precision predictions and the latest theoretical developments for cross sections calculations to higher orders. We include an overview of our current information on parton distributions and discuss various Standard Model reactions such as W ± /Z-boson, Higgs boson or top quark production. (orig.)
Regularities in hadron systematics, Regge trajectories and a string quark model
International Nuclear Information System (INIS)
Chekanov, S.V.; Levchenko, B.B.
2006-08-01
An empirical principle for the construction of a linear relationship between the total angular momentum and squared-mass of baryons is proposed. In order to examine linearity of the trajectories, a rigorous least-squares regression analysis was performed. Unlike the standard Regge-Chew-Frautschi approach, the constructed trajectories do not have non-linear behaviour. A similar regularity may exist for lowest-mass mesons. The linear baryonic trajectories are well described by a semi-classical picture based on a spinning relativistic string with tension. The obtained numerical solution of this model was used to extract the (di)quark masses. (orig.)
International Nuclear Information System (INIS)
Dymski, T.C.
1976-01-01
For high energy scattering of pseudoscalar particles on spin 1 / 2 particles, the transition amplitude (for a given signature) is constructed as an infinite sum over spin of boson exchange graphs of the Feynman type, each of which has impact parameters up to some value R completely removed. This amplitude is advanced as a field theoretic realization of the nondiffractive component of Harari's dual absorption model. Comparing with π/sup +-/p→π/sup +-/p and π - p→π 0 n data shows that the imaginary parts of both helicity amplitudes are excellent, for either signature
Monte Carlo simulations of hadronic fragmentation functions using the Nambu-Jona-Lasinio-jet model
International Nuclear Information System (INIS)
Matevosyan, Hrayr H.; Thomas, Anthony W.; Bentz, Wolfgang
2011-01-01
The recently developed Nambu-Jona-Lasinio--jet model is used as an effective chiral quark theory to calculate the quark fragmentation functions to pions, kaons, nucleons, and antinucleons. The effects of the vector mesons ρ, K * , and φ on the production of secondary pions and kaons are included. The fragmentation processes to nucleons and antinucleons are described by using the quark-diquark picture, which has been shown to give a reasonable description of quark distribution functions. We incorporate effects of next-to-leading order in the Q 2 evolution, and compare our results with the empirical fragmentation functions.
International Nuclear Information System (INIS)
Kabra, Kavita; Chaudhary, Rubina; Sawhney, R.L.
2008-01-01
The present study is targeted on solar photocatalytic removal of metal ions from wastewater. Photoreductive deposition and dark adsorption of metal ions Cu(II), Ni(II), Pb(II) and Zn(II), using solar energy irradiated TiO 2 , has been investigated. Citric acid has been used as a hole scavenger. Modeling of metal species has been performed and speciation is used as a tool for discussing the photodeposition trends. Ninety-seven percent reductive deposition was obtained for copper. The deposition values of other metals were significantly low [nickel (36.4%), zinc (22.2%) and lead (41.4%)], indicating that the photocatalytic treatment process, using solar energy, was more suitable for wastewater containing Cu(II) ions. In absence of citric acid, the decreasing order deposition was Cu(II) > Ni(II) > Pb(II) > Zn(II), which proves the theoretical thermodynamic predictions about the metals
International Nuclear Information System (INIS)
Batyunya, B.V.
1988-01-01
The inclusive characteristics of the e + e - -annihilation process at LEP energy, generated in the Monte-Carlo LUND model, have been obtained. The question on the choice of the model parameters, determining the rates of 2-,3- and 4-jet events, is discussed. The comparison of the generated event characteristics with the experimental ones obtained at lower energy points to the necessity of a more exact choice of the model parameters determining relative probability of different type hadron production. At the same time the properties of the momentum variable distributions of the generated particles reflect a general experimental picture at lower energy
International Nuclear Information System (INIS)
Mathews, Prakash; Ravindran, V.
2006-01-01
In TeV scale gravity models, for dilepton production at hadron colliders, we present the NLO-QCD corrections for the double differential cross section in the invariant mass and scattering angle. For both ADD and RS models, the quantitative impact of QCD corrections for extra dimension searches at LHC and Tevatron are investigated. We present the K-factors for both ADD and RS models at LHC and Tevatron. Inclusion of QCD corrections to NLO stabilises the cross section with respect to scale variations
Mono-jet, -photon and -Z signals of a supersymmetric (B−L) model at the Large Hadron Collider
Energy Technology Data Exchange (ETDEWEB)
Abdallah, W. [Center for Fundamental Physics, Zewail City of Science and Technology,6 October City, Giza (Egypt); Department of Mathematics, Faculty of Science, Cairo University,Giza (Egypt); Fiaschi, J. [School of Physics and Astronomy, University of Southampton,Highfield, Southampton (United Kingdom); Khalil, S. [Center for Fundamental Physics, Zewail City of Science and Technology,6 October City, Giza (Egypt); Moretti, S. [School of Physics and Astronomy, University of Southampton,Highfield, Southampton (United Kingdom)
2016-02-23
Search for invisible final states produced at the Large Hadron Collider (LHC) by new physics scenarios are normally carried out resorting to a variety of probes emerging from the initial state, in the form of single-jet, -photon and -Z boson signatures. These are particularly effective for models of Supersymmetry (SUSY) in presence of R-parity conservation, owing to the presence in their spectra of a stable neutralino as a Dark Matter (DM) candidate. We assume here as theoretical framework the Supersymmetric version of the (B−L) extension of the Standard Model (BLSSM), wherein a mediator for invisible decays can be the Z{sup ′} boson present in this scenario. The peculiarity of the signal is thus that the final state objects carry a very large (transverse) missing energy, since the Z{sup ′} is naturally massive and constrained by direct searches and Electro-Weak Precision Tests (EWPTs) to be at least in the TeV scale region. Under these circumstances the efficiency in accessing the invisible final state and rejecting the Standard Model (SM) background is very high. This somehow compensates the rather meagre production rates. Another special feature of this invisible BLSSM signal is its composition, which is often dominated by sneutrino decays (alongside the more traditional neutrino and neutralino modes). Sensitivity of the CERN machine to these two features can therefore help disentangling the BLSSM from more popular SUSY models. We assess in this analysis the scope of the LHC in establishing the aforementioned invisible signals through a sophisticated signal-to-background simulation carried out in presence of parton shower, hadronisation as well as detector effects. We find that significant sensitivity exists already after 300 fb{sup −1} during Run 2. We find that mono-jet events can be readily accessible at the LHC, so as to enable one to claim a prompt discovery, while mono-photon and -Z signals can be used as diagnostic tools of the underlying scenario.
Track segments in hadronic showers in a highly granular scintillator-steel hadron calorimeter
Adloff, C.; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Francis, K.; Repond, J.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Mikami, Y.; Watson, N.K.; Mavromanolakis, G.; Thomson, M.A.; Ward, D.R.; Yan, W.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dannheim, D.; Dotti, A.; Folger, G.; Ivantchenko, V.; Klempt, W.; Kraaij, E.van der; Lucaci-Timoce, A.-I; Ribon, A.; Schlatter, D.; Uzhinskiy, V.; Cârloganu, C.; Gay, P.; Manen, S.; Royer, L.; Tytgat, M.; Zaganidis, N.; Blazey, G.C.; Dyshkant, A.; Lima, J.G.R.; Zutshi, V.; Hostachy, J.-Y; Morin, L.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Morozov, S.; Morgunov, V.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Feege, N.; Garutti, E.; Laurien, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Sudo, Y.; Yoshioka, T.; Dauncey, P.D.; Magnan, A.-M; Bartsch, V.; Wing, M.; Salvatore, F.; Gil, E.Cortina; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Negra, R.Della; Grenier, G.; Han, R.; Ianigro, J-C; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Donckt, M.Vander; Zoccarato, Y.; Alamillo, E.Calvo; Fouz, M.-C; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Lorenzo, S.Conforti di; Cornebise, P.; Doublet, Ph; Dulucq, F.; Fleury, J.; Frisson, T.; der Kolk, N.van; Li, H.; Martin-Chassard, G.; Richard, F.; Taille, Ch de la; Pöschl, R.; Raux, L.; Rouëné, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J-C; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Musat, G.; Ruan, M.; Tran, T.H.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Takeshita, T.; Uozumi, S.; Jeans, D.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.
2013-01-01
We investigate the three dimensional substructure of hadronic showers in the CALICE scintillator-steel hadronic calorimeter. The high granularity of the detector is used to find track segments of minimum ionising particles within hadronic showers, providing sensitivity to the spatial structure and the details of secondary particle production in hadronic cascades. The multiplicity, length and angular distribution of identified track segments are compared to GEANT4 simulations with several different shower models. Track segments also provide the possibility for in-situ calibration of highly granular calorimeters.
International Nuclear Information System (INIS)
Wiedner, Ulrich
2011-01-01
The new FAIR facility in Darmstadt has a broad program in the field of hadron and nuclear physics utilizing ion beams with unprecedented intensity and accuracy. The hadron physics program centers around the the high-energy storage ring HESR for antiprotons and the PANDA experiment that is integrated in it. The physics program includes among others topics like hadron spectroscopy in the charmonium mass region and below, hyperon physics, electromagnetic processes and charm in nuclei.
Hadronic resonances at FAIR energies
International Nuclear Information System (INIS)
Vogel, Sascha
2013-01-01
These proceedings cover the analysis of hadronic resonances in heavy ion collisions. The model used for these studies is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. The model will be briefly explained, resonance observables will be highlighted and various kinematical issues will be investigated. Special emphasis will be put on the FAIR energy regime, especially highlighting the Compressed Baryonic Matter (CBM) program.
Hadronization of the quark-gluon plasma
International Nuclear Information System (INIS)
Mueller, B.; Sano, M.; Sato, H.; Schaefer, A.
1986-11-01
We construct a model for hadronization of the quark-gluon plasma, based on the relativistic coalescence model. We relate the coalescence amplitude to the one-particle Wigner function for quarks in the plasma. The relation between the Wigner function and the nucleon structure function is pointed out. We derive explicit expressions for the production of mesons and baryons in the framework of the relativistic harmonic oscillator model of hadronic structure. (author)
Structure of hadrons. Proceedings
International Nuclear Information System (INIS)
Feldmeier, H.; Knoll, J.; Noerenberg, W.; Wambach, J.
2001-01-01
The following topics were dealt with: Hadronic reactions and resonances, structure of mesons, baryons, glueballs, and hybrids, physics with strange and charmed quarks, future projects and facilities. (HSI)
Distribution over pT of direct secondary ha drons in hadron-hadron and hadron-nucleus collisions
International Nuclear Information System (INIS)
Braun, V.M.
1986-01-01
Transverse momentum distributions of direct secondary hadrons produced in proton, pion and kaon collisons with nucleons and nuclei are calculated in the additive quark model. Results of calculations are compared to the experimental data on production of neutral strange particles
Hadron production from a boiling quark soup
International Nuclear Information System (INIS)
Bohr, H.; Nielsen, H.B.
1977-01-01
A thermodynamical quark model is presented which can predict cross sections for particle production in hadronic interactions at high energies. In this model a hadronic collision gives rise to a soup of quarks and antiquarks at some temperature kT approximately 170 MeV. Results for inclusive meson production cross sections look promising in comparison with experiments. A formula for the inclusive cross section is given. (Auth.)
Quark-hadron duality in meson physics
International Nuclear Information System (INIS)
Anisovich, V.V.
1994-01-01
Quark hadron dualism is discussed, based on observing the changes in the quark model characteristics after the inclusion into hadron degrees of freedom. A standard version of the potential model is presented. The potential which is responsible for the formation of mesons may be divided into two pieces: a short-range part for distances about 0.3 - 0.5 fm and a long-range part at distances more than 1 fm. (R.P.). 5 refs., 2 figs
Quark-hadron duality in meson physics
Energy Technology Data Exchange (ETDEWEB)
Anisovich, V.V. [Petersburg Nuclear Physics Inst., Gatchina (Russian Federation)
1994-12-31
Quark hadron dualism is discussed, based on observing the changes in the quark model characteristics after the inclusion into hadron degrees of freedom. A standard version of the potential model is presented. The potential which is responsible for the formation of mesons may be divided into two pieces: a short-range part for distances about 0.3 - 0.5 fm and a long-range part at distances more than 1 fm. (R.P.). 5 refs., 2 figs.
Hadron cascades produced by electromagnetic cascades
International Nuclear Information System (INIS)
Nelson, W.R.; Jenkins, T.M.; Ranft, J.
1986-12-01
A method for calculating high energy hadron cascades induced by multi-GeV electron and photon beams is described. Using the EGS4 computer program, high energy photons in the EM shower are allowed to interact hadronically according to the vector meson dominance (VMD) model, facilitated by a Monte Carlo version of the dual multistring fragmentation model which is used in the hadron cascade code FLUKA. The results of this calculation compare very favorably with experimental data on hadron production in photon-proton collisions and on the hadron production by electron beams on targets (i.e., yields in secondary particle beam lines). Electron beam induced hadron star density contours are also presented and are compared with those produced by proton beams. This FLUKA-EGS4 coupling technique could find use in the design of secondary beams, in the determination high energy hadron source terms for shielding purposes, and in the estimation of induced radioactivity in targets, collimators and beam dumps
International Nuclear Information System (INIS)
Schwitters, R.F.
1975-01-01
A report is given of the knowledge obtained from SPEAR about hadron production in e + e - annihilation since the discovery of the new particles. Included are the SPEAR magnetic detector, the total cross sections, mean charged multiplicity and energy, inclusive momentum spectra, and hadron angular distribution
International Nuclear Information System (INIS)
Ernst, David J.
1992-01-01
At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front
International Nuclear Information System (INIS)
De, S.S.
1989-01-01
The paper deals with the space-time structure of the sub-atomic world and attempts to construct the fields of the constitutents of the hadrons. Then it is attempted to construct the fields of the hadrons from these micro-fields. (autho r). 24 refs
Perspectives in hadron spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Richard, J.M. [Universite Joseph Fourier-IN2P3-CNRS, Lab. de Physique Subatomique et Cosmologie, 38 - Grenoble (France)
2005-07-01
A brief survey is presented of selected recent results on hadron spectroscopy and related theoretical studies. Among the new hadron states, some of them are good candidates for exotic structures: chiral partners of ground-states, hybrid mesons (quark, antiquark and constituent gluon), four-quark states, or meson-meson molecules.
Energy Technology Data Exchange (ETDEWEB)
Ernst, David J.
1992-11-15
At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front.
Hadronic degrees of freedom in relativistic heavy-ion collisions
International Nuclear Information System (INIS)
Otsuka, Naohiko
2001-01-01
Relativistic heavy-ion collisions at AGS energies are studied by using an new developed hadronic cascade model, HANDEL which includes a few hadronic degrees of freedom. The spectra of hadron-hadron, hadron-nucleus and nucleus-nucleus reactions at AGS energies are well reproduced by HANDEL. It is confirmed that the infinite matter described by HANDEL has particle fractions which are expected from grand canonical ensemble. When we compare the thermal evolution of Au+Au collision from HANDEL with the result from JAM which has larger hadronic degree of freedoms, we find both models give similar evolution of temperature, against naive expectation. We argue that this results can be interpretated if the particles in formation time works as the additional effective hadronic degrees of freedom. (author)
International Nuclear Information System (INIS)
Strugalski, Z.
1981-01-01
Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei
Explaining dark matter and neutrino mass in the light of TYPE-II seesaw model
Biswas, Anirban; Shaw, Avirup
2018-02-01
With the motivation of simultaneously explaining dark matter and neutrino masses, mixing angles, we have invoked the Type-II seesaw model extended by an extra SU(2) doublet Φ. Moreover, we have imposed a Z2 parity on Φ which remains unbroken as the vacuum expectation value of Φ is zero. Consequently, the lightest neutral component of Φ becomes naturally stable and can be a viable dark matter candidate. On the other hand, light Majorana masses for neutrinos have been generated following usual Type-II seesaw mechanism. Further in this framework, for the first time we have derived the full set of vacuum stability and unitarity conditions, which must be satisfied to obtain a stable vacuum as well as to preserve the unitarity of the model respectively. Thereafter, we have performed extensive phenomenological studies of both dark matter and neutrino sectors considering all possible theoretical and current experimental constraints. Finally, we have also discussed a qualitative collider signatures of dark matter and associated odd particles at the 13 TeV Large Hadron Collider.
Prospects of type-II seesaw models at future colliders in light of the DAMPE e+e- excess
Sui, Yicong; Zhang, Yongchao
2018-05-01
The DAMPE e+e- excess at around 1.4 TeV could be explained in the type-II seesaw model with a scalar dark mater D which is stabilized by a discrete Z2 symmetry. The simplest scenario is the annihilation D D →H++H- followed by the subsequent decay H±±→e±e±, with both the DM and triplet scalars roughly 3 TeV with a small mass splitting. In addition to the Drell-Yan process at future 100 TeV hadron colliders, the doubly charged components could also be produced at lepton colliders like ILC and CLIC in the off shell mode and mediate lepton flavor violating processes e+e-→ℓi±ℓj∓ (with i ≠j ). A wide range of parameter space of the type-II seesaw could be probed, which are well below the current stringent lepton flavor constraints.
CP violation in $b$ hadrons at LHCb
Hicheur, Adlene
2017-01-01
The most recent results on $CP$ violation in b hadrons obtained by the LHCb Collaboration with Run I and years 2015-2016 of Run II are reviewed. The different types of violation are covered by the studies presented in this paper.
Constraints on hadronically decaying dark matter
Energy Technology Data Exchange (ETDEWEB)
Garny, Mathias [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Tran, David [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy
2012-05-15
We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.
Heavy ion and hadron reactions in emulsion
International Nuclear Information System (INIS)
Otterlund, I.
1979-04-01
Recent results from heavy ion and hadron reactions in emulsion are reviewed. General properties of hadron-reaction multiplicities and their correlation to the production of recoiling protons are given. Properties of pseudo-rapidity distributions of shower-particles especially the particle production in the central region of pseudo-rapidity will be discussed. Non-peripheral heavy ion reactions are compared to recent participant-spectator model calculations. Very energetic cosmic ray events will be examined in the light of recent results from hadron-nucleus reactions. (author)
Constraints on hadronically decaying dark matter
International Nuclear Information System (INIS)
Garny, Mathias; Ibarra, Alejandro; Tran, David; Minnesota Univ., Minneapolis, MN
2012-05-01
We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.
Furuseth, Sondre
2017-01-01
The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. This report discusses results from an implementation of the weak-strong model, studying the effects of head-on beam-beam interactions. The assumptions has been shown to be valid for configurations where the growth and losses of the beam are small. The tracking has been done using an original code which applies graphic cards to reduce the computation time. The bunches in the beams have been modelled cylindrically symmetrical, based on a Gaussian distribution in three dimensions. This choice fits well with bunches...
Heavy leptons at hadron colliders
International Nuclear Information System (INIS)
Ohnemus, J.E.
1987-01-01
The recent advent of high energy hadron colliders capable of producing weak bosons has opened new vistas for particle physics research, including the search for a possible fourth generation heavy charged lepton, which is the primary topic of the thesis. Signals for identifying a new heavy lepton have been calculated and compared to Standard Model backgrounds. Results are presented for signals at the CERN collider, the Fermilab collider, and the proposed Superconducting Supercollider
Vayenas, Constantinos G
2012-01-01
This book shows that the strong interaction forces, which keep hadrons and nuclei together, are relativistic gravitational forces exerted between very small particles in the mass range of neutrinos. First, this book considers the problematic motion of two charged particles under the influence of electrostatic and gravitational forces only, which shows that bound states are formed by following the same semi-classical methodology used by Bohr to describe the H atom. This approach is also coupled with Newton's gravitational law and with Einstein's special relativity. The results agree with experi
Signatures of Parton Exogamy in $e^+ e^- \\to W^+ W^- \\to$ hadrons
Ellis, Jonathan Richard; Ellis, John; Geiger, Klaus
1997-01-01
We propose possible signatures of `exogamous' combinations between partons in the different W+ and W- hadron showers in e+e- -> W+W- events with purely hadronic final states. Within the space-time model for hadronic shower development that we have proposed previously, we find a possible difference of about 10 % between the mean hadronic multiplicity in such purely hadronic final states and twice the hadronic multiplicity in events in which one W decays hadronically and the other leptonically, i.e., \
International Nuclear Information System (INIS)
Anon.
1987-01-01
With much particle physics research using particle beams to probe the behaviour of the quark constituents deep inside nucleons and other strongly interacting particles (hadrons), it is easy to overlook the progress being made through hadron spectroscopy – the search for and classification of rare particles – and the way it has increased our understanding of quark physics. One way of remedying this was to attend the stimulating and encouraging Hadron 87 meeting held earlier this year at the Japanese KEK Laboratory, where Jonathan Rosner from Chicago's Enrico Fermi Institute gave the concluding talk
Hadron accelerators in medicine
International Nuclear Information System (INIS)
Amaldi, U.
1996-01-01
The application of hadron accelerators (protons and light ions) in cancer therapy is discussed. After a brief introduction on the rationale for the use of heavy charged particles in radiation therapy, a discussion is given on accelerator technology and beam delivery systems. Next, existing and planned facilities are briefly reviewed. The Italian Hadron-therapy Project is then described in some detail, with reference ro both the National Centre for Oncological Hadron-therapy and the design of different types of compact proton accelerators aimed at introducing proton therapy in a large umber of hospitals. (author)
Energy Technology Data Exchange (ETDEWEB)
Anon.
1987-09-15
With much particle physics research using particle beams to probe the behaviour of the quark constituents deep inside nucleons and other strongly interacting particles (hadrons), it is easy to overlook the progress being made through hadron spectroscopy – the search for and classification of rare particles – and the way it has increased our understanding of quark physics. One way of remedying this was to attend the stimulating and encouraging Hadron 87 meeting held earlier this year at the Japanese KEK Laboratory, where Jonathan Rosner from Chicago's Enrico Fermi Institute gave the concluding talk.
Flemsæter, Bjorn
2000-01-01
The temperature of the superconducting magnets for the 27 km LHC particle accelerator under construction at CERN is a control parameter with strict operating constraints imposed by (a) the maximum temperature at which the magnets can operate, (b) the cooling capacity of the cryogenic system, (c) the variability of applied heat loads and (d) the accuracy of the instrumentation. A pilot plant for studying aspects beyond single magnet testing has been constructed. This magnet test string is a 35-m full-scale model if the LHC and consists of four superconducting cryogmagnets operating in a static bath of He II at 1.9 K. An experimental investigation of the properties dynamic characteristics of the 1.9 K cooling loop of the magnet test string has been carried out. A first principle model of the system has been created. A series of experiments designed for system identification purposes have been carried out, and black box models of the system have been created on the basis on the recorded data. A Model Predictive ...
Workshop on Hadron-Hadron & Cosmic-Ray Interactions at multi-TeV Energies
Alessandro, B; Bergman, D; Bongi, M; Bunyatyan, A; Cazon, L; d'Enterria, D; de Mitri, I; Doll, P; Engel, R; Eggert, K; Garzelli, M; Gerhardt, L; Gieseke, S; Godbole, R; Grosse-Oetringhaus, J F; Gustafson, G; Hebbeker, T; Kheyn, L; Kiryluk, J; Lipari, P; Ostapchenko, S; Pierog, T; Piskounova, O; Ranft, J; Rezaeian, A; Rostovtsev, A; Sakurai, N; Sapeta, S; Schleich, S; Schulz, H; Sjostrand, T; Sonnenschein, L; Sutton, M; Ulrich, R; Werner, K; Zapp, K; CRLHC10; CRLHC 10
2011-01-01
The workshop on "Hadron-Hadron and Cosmic-Ray Interactions at multi-TeV Energies" held at the ECT* centre (Trento) in Nov.-Dec. 2010 gathered together both theorists and experimentalists to discuss issues of the physics of high-energy hadronic interactions of common interest for the particle, nuclear and cosmic-ray communities. QCD results from collider experiments -- mostly from the LHC but also from the Tevatron, RHIC and HERA -- were discussed and compared to various hadronic Monte Carlo generators, aiming at an improvement of our theoretical understanding of soft, semi-hard and hard parton dynamics. The latest cosmic-ray results from various ground-based observatories were also presented with an emphasis on the phenomenological modeling of the first hadronic interactions of the extended air-showers generated in the Earth atmosphere. These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.
Vassiliev, Oleg N.; Grosshans, David R.; Mohan, Radhe
2017-10-01
We propose a new formalism for calculating parameters α and β of the linear-quadratic model of cell survival. This formalism, primarily intended for calculating relative biological effectiveness (RBE) for treatment planning in hadron therapy, is based on a recently proposed microdosimetric revision of the single-target multi-hit model. The main advantage of our formalism is that it reliably produces α and β that have correct general properties with respect to their dependence on physical properties of the beam, including the asymptotic behavior for very low and high linear energy transfer (LET) beams. For example, in the case of monoenergetic beams, our formalism predicts that, as a function of LET, (a) α has a maximum and (b) the α/β ratio increases monotonically with increasing LET. No prior models reviewed in this study predict both properties (a) and (b) correctly, and therefore, these prior models are valid only within a limited LET range. We first present our formalism in a general form, for polyenergetic beams. A significant new result in this general case is that parameter β is represented as an average over the joint distribution of energies E 1 and E 2 of two particles in the beam. This result is consistent with the role of the quadratic term in the linear-quadratic model. It accounts for the two-track mechanism of cell kill, in which two particles, one after another, damage the same site in the cell nucleus. We then present simplified versions of the formalism, and discuss predicted properties of α and β. Finally, to demonstrate consistency of our formalism with experimental data, we apply it to fit two sets of experimental data: (1) α for heavy ions, covering a broad range of LETs, and (2) β for protons. In both cases, good agreement is achieved.
PARALLEL MEASUREMENT AND MODELING OF TRANSPORT IN THE DARHT II BEAMLINE ON ETA II
International Nuclear Information System (INIS)
Chambers, F W; Raymond, B A; Falabella, S; Lee, B S; Richardson, R A; Weir, J T; Davis, H A; Schultze, M E
2005-01-01
To successfully tune the DARHT II transport beamline requires the close coupling of a model of the beam transport and the measurement of the beam observables as the beam conditions and magnet settings are varied. For the ETA II experiment using the DARHT II beamline components this was achieved using the SUICIDE (Simple User Interface Connecting to an Integrated Data Environment) data analysis environment and the FITS (Fully Integrated Transport Simulation) model. The SUICIDE environment has direct access to the experimental beam transport data at acquisition and the FITS predictions of the transport for immediate comparison. The FITS model is coupled into the control system where it can read magnet current settings for real time modeling. We find this integrated coupling is essential for model verification and the successful development of a tuning aid for the efficient convergence on a useable tune. We show the real time comparisons of simulation and experiment and explore the successes and limitations of this close coupled approach
NSLS-II: Nonlinear Model Calibration for Synchrotrons
Energy Technology Data Exchange (ETDEWEB)
Bengtsson, J.
2010-10-08
This tech note is essentially a summary of a lecture we delivered to the Acc. Phys. Journal Club Apr, 2010. However, since the estimated accuracy of these methods has been naive and misleading in the field of particle accelerators, i.e., ignores the impact of noise, we will elaborate on this in some detail. A prerequisite for a calibration of the nonlinear Hamiltonian is that the quadratic part has been understood, i.e., that the linear optics for the real accelerator has been calibrated. For synchrotron light source operations, this problem has been solved by the interactive LOCO technique/tool (Linear Optics from Closed Orbits). Before that, in the context of hadron accelerators, it has been done by signal processing of turn-by-turn BPM data. We have outlined how to make a basic calibration of the nonlinear model for synchrotrons. In particular, we have shown how this was done for LEAR, CERN (antiprotons) in the mid-80s. Specifically, our accuracy for frequency estimation was {approx} 1 x 10{sup -5} for 1024 turns (to calibrate the linear optics) and {approx} 1 x 10{sup -4} for 256 turns for tune footprint and betatron spectrum. For a comparison, the estimated tune footprint for stable beam for NSLS-II is {approx}0.1. Since the transverse damping time is {approx}20 msec, i.e., {approx}4,000 turns. There is no fundamental difference for: antiprotons, protons, and electrons in this case. Because the estimated accuracy for these methods in the field of particle accelerators has been naive, i.e., ignoring the impact of noise, we have also derived explicit formula, from first principles, for a quantitative statement. For e.g. N = 256 and 5% noise we obtain {delta}{nu} {approx} 1 x 10{sup -5}. A comparison with the state-of-the-arts in e.g. telecomm and electrical engineering since the 60s is quite revealing. For example, Kalman filter (1960), crucial for the: Ranger, Mariner, and Apollo (including the Lunar Module) missions during the 60s. Or Claude Shannon et al
NSLS-II: Nonlinear Model Calibration for Synchrotrons
International Nuclear Information System (INIS)
Bengtsson, J.
2010-01-01
This tech note is essentially a summary of a lecture we delivered to the Acc. Phys. Journal Club Apr, 2010. However, since the estimated accuracy of these methods has been naive and misleading in the field of particle accelerators, i.e., ignores the impact of noise, we will elaborate on this in some detail. A prerequisite for a calibration of the nonlinear Hamiltonian is that the quadratic part has been understood, i.e., that the linear optics for the real accelerator has been calibrated. For synchrotron light source operations, this problem has been solved by the interactive LOCO technique/tool (Linear Optics from Closed Orbits). Before that, in the context of hadron accelerators, it has been done by signal processing of turn-by-turn BPM data. We have outlined how to make a basic calibration of the nonlinear model for synchrotrons. In particular, we have shown how this was done for LEAR, CERN (antiprotons) in the mid-80s. Specifically, our accuracy for frequency estimation was ∼ 1 x 10 -5 for 1024 turns (to calibrate the linear optics) and ∼ 1 x 10 -4 for 256 turns for tune footprint and betatron spectrum. For a comparison, the estimated tune footprint for stable beam for NSLS-II is ∼0.1. Since the transverse damping time is ∼20 msec, i.e., ∼4,000 turns. There is no fundamental difference for: antiprotons, protons, and electrons in this case. Because the estimated accuracy for these methods in the field of particle accelerators has been naive, i.e., ignoring the impact of noise, we have also derived explicit formula, from first principles, for a quantitative statement. For e.g. N = 256 and 5% noise we obtain (delta)ν ∼ 1 x 10 -5 . A comparison with the state-of-the-arts in e.g. telecomm and electrical engineering since the 60s is quite revealing. For example, Kalman filter (1960), crucial for the: Ranger, Mariner, and Apollo (including the Lunar Module) missions during the 60s. Or Claude Shannon et al since the 40s for that matter. Conclusion: what
International Nuclear Information System (INIS)
Kaplan, D.B.
1995-01-01
I give a brief and selective overview of QCD as it pertains to determining hadron structure, and the relevant directions in this field for nuclear theory. This document is intended to start discussion about priorities, not end it
International Nuclear Information System (INIS)
Ferbel, T.
1976-01-01
Recent experimental results from studies of hadron interactions at Fermilab are surveyed. Elastic, total and charge-exchange cross section measurements, diffractive phenomena, and inclusive production, using nuclear as well as hydrogen targets, are discussed in these lectures
Energy Technology Data Exchange (ETDEWEB)
NONE
2006-07-01
The following topics were ealt with: Hadron physics with proton and deuteron probes, physics projects with Georgian participation, spin physics with antiprotons and leptons, spin filtering experiments, ISTC projects, technical issues for FAIR. (HSI)
Hadron multiplicities at COMPASS
Energy Technology Data Exchange (ETDEWEB)
Du Fresne von Hohenesche, Nicolas [Institut fuer Kernphysik, Universitaet Mainz, Johann-Joachim-Becher-Weg 45, 55128 Mainz (Germany); Collaboration: COMPASS Collaboration
2014-07-01
Quark fragmentation functions (FF) D{sub q}{sup h}(z,Q{sup 2}) describe final-state hadronization of quarks q into hadrons h. The FFs can be extracted from hadron multiplicities produced in semi-inclusive deep inelastic scattering. The COMPASS collaboration has recently measured charged hadron multiplicities for identified pions and kaons using a 160 GeV/c muon beam impinging on an iso-scalar target. The data cover a large kinematical range and provide an important input for global QCD analyses of world data at NLO, aiming at the determination of FFs in particular in the strange quark sector. The newest results from COMPASS on pion and kaon multiplicities will be presented.
High energy hadron spin-flip amplitude
International Nuclear Information System (INIS)
Selyugin, O.V.
2016-01-01
The high-energy part of the hadron spin-flip amplitude is examined in the framework of the new high-energy general structure (HEGS) model of the elastic hadron scattering at high energies. The different forms of the hadron spin-flip amplitude are compared in the impact parameter representation. It is shown that the existing experimental data of the proton-proton and proton-antiproton elastic scattering at high energy in the region of the diffraction minimum and at large momentum transfer give support in the presence of the energy-independent part of the hadron spin-flip amplitude with the momentum dependence proposed in the works by Galynskii-Kuraev. [ru
Sum rules for quasifree scattering of hadrons
Peterson, R. J.
2018-02-01
The areas d σ /d Ω of fitted quasifree scattering peaks from bound nucleons for continuum hadron-nucleus spectra measuring d2σ /d Ω d ω are converted to sum rules akin to the Coulomb sums familiar from continuum electron scattering spectra from nuclear charge. Hadronic spectra with or without charge exchange of the beam are considered. These sums are compared to the simple expectations of a nonrelativistic Fermi gas, including a Pauli blocking factor. For scattering without charge exchange, the hadronic sums are below this expectation, as also observed with Coulomb sums. For charge exchange spectra, the sums are near or above the simple expectation, with larger uncertainties. The strong role of hadron-nucleon in-medium total cross sections is noted from use of the Glauber model.
Hadronic production of glueballs
International Nuclear Information System (INIS)
Lindenbaum, S.J.
1983-01-01
Local Gauge Invariance of SU(3)/sub c/ and color confinement would require that the only hadrons in the world be glueballs. However, when we add the quarks and obtain QCD it is experimentally clear that quark built states mask the expected glueballs. Thus discovery of glueballs is essential for the viability of QCD. Papers presented at the 1983 International Europhysics Conference on High Energy Physics on the hadronic production of glueballs and searches for glueballs are reviewed
Banfi, Andrea
2016-01-01
Jet physics is an incredibly rich subject detailing the narrow cone of hadrons and other particles produced by the hadronization of a quark or gluon in a particle physics or heavy ion experiment. This book is a general overview of jet physics for scientists not directly involved in the field. It presents the basic experimental and theoretical problems arising when dealing with jets, and describing the solutions proposed in recent years.
Hadronization in nuclear matter
International Nuclear Information System (INIS)
Anton, G.; Blok, H.P.; Boudard, A.; Kopeliovich, B.
1993-01-01
The investigation of the space time structure of quark propagation and hadronization is proposed by studying particle production in deep-inelastic scattering of electrons from nucleons and nuclei with high statistics. A 15 to 30 GeV electron beam impinging on targets of hydrogen, deuterium, helium, carbon and lead is planned to be used and the final state hadrons are to be detected in a large solid angle device. (authors). 48 refs., 13 figs., 4 tabs
International Nuclear Information System (INIS)
Martin, F.
1981-03-01
The x dependence of hadron structure functions is investigated. If quarks can exist in very low mass states (10 MeV for d and u quarks) the pion structure function is predicted to behave like (1-x) and not (1-x) 2 in a x-region around 1. Relativistic and non-relativistic quark bound state pictures of hadrons are considered together with their relation with the Q 2 evolution of structure functions. Good agreement with data is in general obtained
Testing of a one dimensional model for Field II calibration
DEFF Research Database (Denmark)
Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten
2008-01-01
Field II is a program for simulating ultrasound transducer fields. It is capable of calculating the emitted and pulse-echoed fields for both pulsed and continuous wave transducers. To make it fully calibrated a model of the transducer’s electro-mechanical impulse response must be included. We...... examine an adapted one dimensional transducer model originally proposed by Willatzen [9] to calibrate Field II. This model is modified to calculate the required impulse responses needed by Field II for a calibrated field pressure and external circuit current calculation. The testing has been performed...... to the calibrated Field II program for 1, 4, and 10 cycle excitations. Two parameter sets were applied for modeling, one real valued Pz27 parameter set, manufacturer supplied, and one complex valued parameter set found in literature, Alguer´o et al. [11]. The latter implicitly accounts for attenuation. Results show...
Asymmetric Gepner models II. Heterotic weight lifting
Energy Technology Data Exchange (ETDEWEB)
Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); IMAPP, Radboud Universiteit, Nijmegen (Netherlands)
2011-05-21
A systematic study of 'lifted' Gepner models is presented. Lifted Gepner models are obtained from standard Gepner models by replacing one of the N=2 building blocks and the E{sub 8} factor by a modular isomorphic N=0 model on the bosonic side of the heterotic string. The main result is that after this change three family models occur abundantly, in sharp contrast to ordinary Gepner models. In particular, more than 250 new and unrelated moduli spaces of three family models are identified. We discuss the occurrence of fractionally charged particles in these spectra.
Asymmetric Gepner models II. Heterotic weight lifting
International Nuclear Information System (INIS)
Gato-Rivera, B.; Schellekens, A.N.
2011-01-01
A systematic study of 'lifted' Gepner models is presented. Lifted Gepner models are obtained from standard Gepner models by replacing one of the N=2 building blocks and the E 8 factor by a modular isomorphic N=0 model on the bosonic side of the heterotic string. The main result is that after this change three family models occur abundantly, in sharp contrast to ordinary Gepner models. In particular, more than 250 new and unrelated moduli spaces of three family models are identified. We discuss the occurrence of fractionally charged particles in these spectra.
Integrating Seasonal Oscillations into Basel II Behavioural Scoring Models
Directory of Open Access Journals (Sweden)
Goran Klepac
2007-09-01
Full Text Available The article introduces a new methodology of temporal influence measurement (seasonal oscillations, temporal patterns for behavioural scoring development purposes. The paper shows how significant temporal variables can be recognised and then integrated into the behavioural scoring models in order to improve model performance. Behavioural scoring models are integral parts of the Basel II standard on Internal Ratings-Based Approaches (IRB. The IRB approach much more precisely reflects individual risk bank profile.A solution of the problem of how to analyze and integrate macroeconomic and microeconomic factors represented in time series into behavioural scorecard models will be shown in the paper by using the REF II model.
anti ee annihilation into hadrons from dual unitarisation
International Nuclear Information System (INIS)
Hong-mo, C.
1976-09-01
By grafting to the dual unitarisation scheme for hadron reactions a quark-current coupling suggested by the parton model, a model is obtained for anti ee annihilations in which the conversion of quarks into final hadrons is specific. As a first application, the correction to the value of R given by the parton model is estimated. (author)
Chernyavskaya, Nadezda
2017-01-01
A search for the standard model Higgs boson produced by vector boson fusion in the fully hadronic four-jet topology is presented. The analysis is based on 2.3 fb$^{-1}$ of proton-proton collision data at $\\sqrt{s}$ = 13 TeV collected by CMS in 2015. Upper limits, at 95\\% confidence level, on the production cross section times branching fraction of the Higgs boson decaying to bottom quarks, are derived for a Higgs boson mass of 125 GeV. The fitted signal strength relative to the expectation for the standard model Higgs boson is obtained. Results are also combined with the ones obtained with Run1 data at $\\sqrt{s}$ = 8 TeV collected in 2012.
Energy Technology Data Exchange (ETDEWEB)
Todorov, T
1993-05-01
This thesis describes the determination of the electroweak parameters from the measurements of the total hadronic cross-section by the DELPHI experiment at LEP-I. The analysed data was taken in the years 1991 and 1992; a previous analysis of the data taken in 1990 is included in the final fits. The first part of the thesis describes the interest of the measurement of the Z{sup 0} resonance parameters in the framework of the Standard Model as well as their implications for alternative models. The Standard Model predictions are described in some detail, and their precision is estimated. Then follows a brief description of the LEP collider, of the measurement of the collision energy, and of the experimental setup. A chapter is devoted to the description of the luminosity measurement, essential for the determination of total cross-sections. The measurement of the hadronic cross-section (event selection, study of backgrounds, study of sources of systematic uncertainties) is described in detail in the next chapter. Then follows a description of the method of the extraction of the resonance parameters, and a discussion of the uncertainties in their determination. The values obtained are interpreted in the framework of the Standard Model, as well as in the framework of some more general theories. Finally, the event generator for hadron production in two-photon collisions is described in the appendix. (author). 69 refs., 51 figs., 9 tabs., 1 ann.
International Nuclear Information System (INIS)
Ruthmann, Nils
2014-01-01
This thesis presents a search for Standard Model (SM) Higgs boson decays to a pair of τ leptons in the lepton-hadron final state with the ATLAS detector at the Large Hadron Collider (LHC). The analysis is based on proton-proton collision data recorded during Run 1 of the LHC, corresponding to integrated luminosities of 4.5 fb"-"1 and 20.3 fb"-"1 at centre-of-mass energies of 7 TeV and 8 TeV, respectively. Background events from various SM processes contribute to the selected event sample at a high rate. Their contribution is efficiently separated from the expected Higgs boson signal by using boosted decision trees (BDT) in two analysis categories, which are enriched in events emerging from vector boson fusion and gluon fusion processes. The expected number of events from background processes is modelled using data-driven estimation techniques. The signal contribution is measured using a maximum likelihood fit of the BDT output distributions. An excess of events over the expected level of background events is found and corresponds to an observed (expected) significance of 2.3(2.4) standard deviations at a Higgs boson mass hypothesis of 125 GeV. The signal strength normalised to the Standard Model expectation is measured to be 0.98"+"0"."5_-_0_._5. A combined analysis of all τ-τ final states rejects the background-only hypothesis at a level of 4.5 standard deviations at m_H=125 GeV, while a significance of 3.5 standard deviations is expected. This provides evidence for the direct coupling of the recently discovered Higgs boson to tau leptons. The measured normalised signal strength of 1.4"+"0"."4"3_-_0_._3_7 is consistent with the predicted Yukawa coupling strength in the Standard Model.
Hadron masses in a gauge theory
International Nuclear Information System (INIS)
De Rujula, A.; Georgi, H.; Glashow, S.L.
1975-01-01
We explore the implications for hadron spectroscopy of the ''standard'' gauge model of weak, electromagnetic, and strong interactions. The model involves four types of fractionally charged quarks, each in three colors, coupling to massless gauge gluons. The quarks are confined within colorless hadrons by a long-range spin-independent force realizing infrared slavery. We use the asymptotic freedom of the model to argue that for the calculation of hadron masses, the short-range quark-quark interaction may be taken to be Coulomb-like. We rederive many successful quark-model mass relations for the low-lying hadrons. Because a specific interaction and symmetry-breaking mechanism are forced on us by the underlying renormalizable gauge field theory, we also obtain new mass relations. They are well satisfied. We develop a qualitative understanding of many features of the hadron mass spectrum, such as the origin and sign of the Σ-Λ mass splitting. Interpreting the newly discovered narrow boson resonances as states of charmonium, we use the model to predict the masses of charmed mesons and baryons
2009-01-01
The CERN Dragon Boat team – the Hadron Dragons – achieved a fantastic result at the "Paddle for Cancer" Dragon Boat Festival at Lac de Joux on 6 September. CERN Hadron Dragons heading for the start line.Under blue skies and on a clear lake, the Hadron Dragons won 2nd place in a hard-fought final, following top times in the previous heats. In a close and dramatic race – neck-and-neck until the final 50 metres – the local Lac-de-Joux team managed to inch ahead at the last moment. The Hadron Dragons were delighted to take part in this festival. No one would turn down a day out in such a friendly and fun atmosphere, but the Dragons were also giving their support to cancer awareness and fund-raising in association with ESCA (English-Speaking Cancer Association of Geneva). Riding on their great success in recent competitions, the Hadron Dragons plan to enter the last Dragon Boat festival of 2009 in Annecy on 17-18 October. This will coincide with t...
Hadronic form factors in kaon photoproduction
Energy Technology Data Exchange (ETDEWEB)
Syukurilla, L., E-mail: tmart@fisika.ui.ac.id; Mart, T., E-mail: tmart@fisika.ui.ac.id [Department Fisika, FMIPA, Universitas Indonesia, Depok, 164242 (Indonesia)
2014-09-25
We have revisited the effect of hadronic form factors in kaon photoproduction process by utilizing an isobaric model developed for kaon photoproduction off the proton. The model is able to reproduce the available experimental data nicely as well as to reveal the origin of the second peak in the total cross section, which was the main source of confusion for decades. Different from our previous study, in the present work we explore the possibility of using different hadronic form factors in each of the KΛN vertices. The use of different hadronic form factors, e.g. dipole, Gaussian, and generalized dipole, has been found to produce a more flexible isobar model, which can provide a significant improvement in the model.
Dutta, S; Kumar, A; Skoczen, B; Soni, H C
2004-01-01
The Short Straight Section (SSS) of the Large Hadron Collider (LHC) may undergo relative displacements between cold-mass and cryostat for the following three reasons: - Fabrication tolerance of interconnection bellows - Global smoothing after pre-alignment - Ground motion in a sector of the LHC tunnel The forces responsible for such displacements stem from finite stiffness of interconnect bellows & metal hoses of the internal piping of the jumper connection and from relatively flexible 'glass fibre reinforced epoxy' (GFRE) composite supports of the cold mass. In addition, the vacuum jacket of the jumper connection and the large sleeves attached to both ends of SSS produce elastic deformations of the cryostat vessel. A unified finite element model consisting of cryostat, large sleeves, vacuum jacket of jumper, interconnection bellows, internal piping of jumper, composite cold supports and alignment jacks has been prepared. The knowledge of the position of the cold mass with respect to its cryostat under va...
Predictive Models and Computational Toxicology (II IBAMTOX)
EPA’s ‘virtual embryo’ project is building an integrative systems biology framework for predictive models of developmental toxicity. One schema involves a knowledge-driven adverse outcome pathway (AOP) framework utilizing information from public databases, standardized ontologies...
Nyala and Bushbuck II: A Harvesting Model.
Fay, Temple H.; Greeff, Johanna C.
1999-01-01
Adds a cropping or harvesting term to the animal overpopulation model developed in Part I of this article. Investigates various harvesting strategies that might suggest a solution to the overpopulation problem without actually culling any animals. (ASK)
Base Flow Model Validation, Phase II
National Aeronautics and Space Administration — The program focuses on turbulence modeling enhancements for predicting high-speed rocket base flows. A key component of the effort is the collection of high-fidelity...
Hadron final states in deep inelastic processes
International Nuclear Information System (INIS)
Bjorken, J.D.
1976-05-01
Lectures are presented dealing mainly with the description and discussion of hadron final states in electroproduction, colliding beams, and neutrino reactions from the point of view of the simple parton model. Also the space-time evolution of final states in the parton model is considered. It is found that the picture of space-time evolution of hadron final states in deep inelastic processes isn't totally trivial and that it can be made consistent with the hypotheses of the parton model. 39 references
Palano, Antimo
2018-01-01
The LHCb experiment is designed to study the properties and decays of heavy ﬂavored hadrons produced in pp collisions at the LHC. The data collected in the LHC Run I enables precision spectroscopy studies of beauty and charm hadrons. The latest results on spectroscopy of conventional and exotic hadrons are reviewed. In particular the discovery of the ﬁrst charmonium pentaquark states in the $J/\\psi p$ system, the possible existence of four-quark states decaying to $J/\\psi \\phi$ and the conﬁrmation of resonant nature of the $Z_c(4430)^−$ mesonic state are discussed. In the sector of charmed baryons, the observation of ﬁve new $\\Omega_c$ states, the observation of the $\\Xi^+_{cc}$ and the study of charmed baryons decaying to $D^0 p$ are presented.
Mallik, Samirnath
2016-01-01
High energy laboratories are performing experiments in heavy ion collisions to explore the structure of matter at high temperature and density. This elementary book explains the basic ideas involved in the theoretical analysis of these experimental data. It first develops two topics needed for this purpose, namely hadron interactions and thermal field theory. Chiral perturbation theory is developed to describe hadron interactions and thermal field theory is formulated in the real-time method. In particular, spectral form of thermal propagators is derived for fields of arbitrary spin and used to calculate loop integrals. These developments are then applied to find quark condensate and hadron parameters in medium, including dilepton production. Finally, the non-equilibrium method of statistical field theory to calculate transport coefficients is reviewed. With technical details explained in the text and appendices, this book should be accessible to researchers as well as graduate students interested in thermal ...
Study of the Weak Charged Hadronic Current in b Decays
Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nisati, A; Nowak, H; Opitz, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F
1997-01-01
Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69$\\pm$0.07(stat.)$\\pm$0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40$\\pm$17\\% of the produced mesons are light--flavored tensor (L=1) mesons. This level of tensor meson production is consistent with the measurement of the $\\pi^0$ multiplicity in the weak charged hadronic current in b decays. \\end{abstract}
Mineral vein dynamics modelling (FRACS II)
International Nuclear Information System (INIS)
Urai, J.; Virgo, S.; Arndt, M.
2016-08-01
The Mineral Vein Dynamics Modeling group ''FRACS'' started out as a team of 7 research groups in its first phase and continued with a team of 5 research groups at the Universities of Aachen, Tuebingen, Karlsruhe, Mainz and Glasgow during its second phase ''FRACS 11''. The aim of the group was to develop an advanced understanding of the interplay between fracturing, fluid flow and fracture healing with a special emphasis on the comparison of field data and numerical models. Field areas comprised the Oman mountains in Oman (which where already studied in detail in the first phase), a siliciclastic sequence in the Internal Ligurian Units in Italy (closed to Sestri Levante) and cores of Zechstein carbonates from a Lean Gas reservoir in Northern Germany. Numerical models of fracturing, sealing and interaction with fluid that were developed in phase I where expanded in phase 11. They were used to model small scale fracture healing by crystal growth and the resulting influence on flow, medium scale fracture healing and its influence on successive fracturing and healing, as well as large scale dynamic fluid flow through opening and closing fractures and channels as a function of fluid overpressure. The numerical models were compared with structures in the field and we were able to identify first proxies for mechanical vein-hostrock properties and fluid overpressures versus tectonic stresses. Finally we propose a new classification of stylolites based on numerical models and observations in the Zechstein cores and continued to develop a new stress inversion tool to use stylolites to estimate depth of their formation.
Mineral vein dynamics modelling (FRACS II)
Energy Technology Data Exchange (ETDEWEB)
Urai, J.; Virgo, S.; Arndt, M. [RWTH Aachen (Germany); and others
2016-08-15
The Mineral Vein Dynamics Modeling group ''FRACS'' started out as a team of 7 research groups in its first phase and continued with a team of 5 research groups at the Universities of Aachen, Tuebingen, Karlsruhe, Mainz and Glasgow during its second phase ''FRACS 11''. The aim of the group was to develop an advanced understanding of the interplay between fracturing, fluid flow and fracture healing with a special emphasis on the comparison of field data and numerical models. Field areas comprised the Oman mountains in Oman (which where already studied in detail in the first phase), a siliciclastic sequence in the Internal Ligurian Units in Italy (closed to Sestri Levante) and cores of Zechstein carbonates from a Lean Gas reservoir in Northern Germany. Numerical models of fracturing, sealing and interaction with fluid that were developed in phase I where expanded in phase 11. They were used to model small scale fracture healing by crystal growth and the resulting influence on flow, medium scale fracture healing and its influence on successive fracturing and healing, as well as large scale dynamic fluid flow through opening and closing fractures and channels as a function of fluid overpressure. The numerical models were compared with structures in the field and we were able to identify first proxies for mechanical vein-hostrock properties and fluid overpressures versus tectonic stresses. Finally we propose a new classification of stylolites based on numerical models and observations in the Zechstein cores and continued to develop a new stress inversion tool to use stylolites to estimate depth of their formation.
Astalos, R.; Bartalini, P.; Belyaev, I.; Bierlich, Ch.; Blok, B.; Buckley, A.; Ceccopieri, F.A.; Cherednikov, I.; Christiansen, J.R.; Ciangottini, D.; Deak, M.; Ducloue, B.; Field, R.; Gaunt, J.R.; Golec-Biernat, K.; Goerlich, L.; Grebenyuk, A.; Gueta, O.; Gunnellini, P.; Helenius, I.; Jung, H.; Kar, D.; Kepka, O.; Klusek-Gawenda, M.; Knutsson, A.; Kotko, P.; Krasny, M.W.; Kutak, K.; Lewandowska, E.; Lykasov, G.; Maciula, R.; Moraes, A.M.; Martin, T.; Mitsuka, G.; Motyka, L.; Myska, M.; Otwinowski, J.; Pierog, T.; Pleskot, V.; Rinaldi, M.; Schafer, W.; Siodmok, A.; Sjostrand, T.; Snigirev, A.; Stasto, A.; Staszewski, R.; Stebel, T.; Strikman, M.; Szczurek, A.; Treleani, D.; Trzebinski, M.; van Haevermaet, H.; van Hameren, A.; van Mechelen, P.; Waalewijn, W.; Wang, W.Y.; MPI@LHC 2014
2014-01-01
Multiple Partonic Interactions are often crucial for interpreting results obtained at the Large Hadron Collider (LHC). The quest for a sound understanding of the dynamics behind MPI - particularly at this time when the LHC is due to start its "Run II" operations - has focused the aim of this workshop. MPI@LHC2014 concentrated mainly on the phenomenology of LHC measurements whilst keeping in perspective those results obtained at previous hadron colliders. The workshop has also debated some of the state-of-the-art theoretical considerations and the modeling of MPI in Monte Carlo event generators. The topics debated in the workshop included: Phenomenology of MPI processes and multiparton distributions; Considerations for the description of MPI in Quantum Chromodynamics (QCD); Measuring multiple partonic interactions; Experimental results on inelastic hadronic collisions: underlying event, minimum bias, forward energy flow; Monte Carlo generator development and tuning; Connections with low-x phenomena, diffractio...
Nelson, Timothy Knight
We describe measurements of the branching ratiosmath> B(B --->D*+p- p-total) =(29.2+/-4.5+/-3.8+/-3.1) ×10-4 B(B- --> D*+p- p -non- res)=( 9.7+/-3.6+/-1.5+/-1.9)× 10- 4 B(B---> D1(2420) 0p-) B(D1( 2420)0--> D*+p- )= (6.9+1.8-1.4 +/-1.1+/-0.4)× 10-4 B(B---> D01( j= / )p- ) B(D01 (j= /) -->D* +p-) = ( 10.6+/-1.9+/-1.7+/-2.3)× 10-4 B(B---> D*2( 2460)0p- )B(D *2( 2460)0--> D*+p- )= (3.1+/- 0.84+/-0.46+/-0.28)×10 -4, using data collected by the CLEO II detector. These measurements provide the first observation of the D01(j=/) with a mass and width of 2.461+0.053- 0.049GeV and 290+110 - 91MeV respectively. The mixing angles between the partial waves and strong phase shifts among the resonances are also measured assuming one possible parameterization of the amplitude. A method allowing full reconstruction of the signal without reconstruction of the D meson in the final state is used. The measurements are extracted using an four-dimensional, unbinned, maximum- likelihood fit to the distributions of the D*+p- mass and the decay angles. The primary element of the CLEO II.V upgrade was the installation of a three-layer Silicon Vertexing Detector. The design and construction of this detector are described in detail.
International Nuclear Information System (INIS)
Quigg, C.
1982-11-01
The subject of hadron jet studies, to judge by the work presented at this workshop, is a maturing field which is still gathering steam. The very detailed work being done in lepton-lepton and lepton-hadron collisions, the second-generation measurements being carried out at Fermilab, the CERN SPS, and the ISR, and the very high energy hard scatterings being observed at the CERN Collider all show enormous promise for increased understanding. Perhaps we shall yet reach that long-sought nirvana in which high-p/sub perpendicular/ collisions become truly simple
International Nuclear Information System (INIS)
Anon.
1987-01-01
'Hadron facilities' – high intensity (typically a hundred microamps), medium energy (30-60 GeV) machines producing intense secondary beams of pions, kaons, etc., are being widely touted as a profitable research avenue to supplement what is learned through the thrust for higher and higher energies. This interest was reflected at an International Workshop on Hadron Facility Technology, held in Santa Fe, New Mexico. As well as invited talks describing the various projects being pushed in the US, Europe and Japan, the meeting included working groups covering linacs, beam dynamics, hardware, radiofrequency, polarized beams and experimental facilities
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 ...
On the hadron formation time in pion-nucleus interaction
International Nuclear Information System (INIS)
Bravina, L.V.; Korotkikh, V.L.; Sarycheva, L.I.; Sivoklokov, S.Yu.
1992-01-01
Differences in the observable characteristics of pion-nucleus interactions at high energy are investigated for two definitions of the hadron formation time. The Monte Carlo simulation of hadron-nucleus interactions and quark-gluon string model for hadron-hadron collisions are used. It is shown that the momentum spectrum of the protons in the target fragmentation region is most sensitive to the definition of the formation time. The inclusive meson and meson resonance spectra are similar in the both versions. 20 refs.; 4 figs.; 1 tab
The Brief Life of a Hadron: QCD unquenched
International Nuclear Information System (INIS)
Pennington, Michael R.
2015-03-01
Once upon a time, the picture of hadrons was of mesons made of a quark and an antiquark, and baryons of three quarks. Though hadrons heavier than the ground states inevitably decay by the strong interaction, the successes of the quark model might suggest their decays are a mere perturbation. However, Eef van Beveren, whose career we celebrate here, recognised that decays are an integral part of the life of a hadron. The channels into which they decay are often essential to their very existence. These hold the secrets of strong coupling QCD and teach us the way quarks really build hadrons.
Measurement of $\\Delta^{++}$(1232) production in hadronic Z decays
Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Allport, P P; Almehed, S; Alvsvaag, S J; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Anykeyev, V B; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bocci, V; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carrilho, P; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Daum, A; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; De Boeck, H; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Dupont, F; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gibbs, M; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Grosdidier, G; Gunnarsson, P; Günther, M; Guy, J; Haedinger, U; Hahn, F; Hahn, M; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Ioannou, P; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Köhne, J H; Köne, B; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Kramer, P H; Krammer, Manfred; Kreuter, C; Królikowski, J; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Lokajícek, M; Loken, J G; López, J M; López-Fernandez, A; López-Aguera, M A; Loukas, D; Lutz, P; Lyons, L; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Meroni, C; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Negri, P; Némécek, S; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Pindo, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Rybin, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schneider, H; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnova, O G; Smith, G R; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stepaniak, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Weierstall, M; Weilhammer, Peter; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zacharatou-Jarlskog, C; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zhigunov, V P; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G
1995-01-01
A measurement of the \\Delta^{++}(1232) inclusive production in hadronic decays of the Z at LEP is presented, based on 1.3 million hadronic events collected~ by the DELPHI~ detector in the 1994 LEP running~ period. The DELPHI ring imaging Cherenkov counters are used for identifying hadrons. The average \\Delta^{++}(1232) multiplicity per hadronic event is 0.079 \\pm 0.015 which is more than a factor of two below the JETSET, HERWIG and UCLA model predictions. It agrees with a recently proposed universal mass dependence of particle production rates in e^{+}e^- annihilations.
Large transverse momenta phenomena in hadron-hadron collisions
International Nuclear Information System (INIS)
McCubbin, N.A.
1981-05-01
The production of particles with large transverse momentum in high energy hadron-hadron collisions is reviewed. The emphasis is placed on the experimental results. These results are discussed in terms of present theoretical ideas on interactions between hadronic constituents, but no attempt is made to review the theoretical work in a comprehensive manner. (author)
International Nuclear Information System (INIS)
Szymanski, P.
2006-09-01
This work concerns soft hadronic interactions which in the Standard Model carry most of the observable cross-section but are not amenable to quantitative predictions due to the very nature of the QCD (Theory of Strong Interactions). In the low momentum transfer region the evolving coupling constant caused perturbation theory to break down. In this situation better experimental understanding of the physics phenomena is needed. One aspect of the soft hadronic interactions will be discussed in this work: transfer of the baryon number from the initial to the final state of the interaction. The past experimental knowledge on this process is presented, reasons for its unsatisfactory status are discussed and condition necessary for improvement are outlined: that is experimental apparatus with superior performance over the full range of available interactions: hadron-hadron collision, hadron-nucleus and nucleus-nucleus interactions. A consistent model-independent picture of the baryon number transfer process emerging from the data on the full range of interactions is shown. It offers serious challenge to theory to provide quantitative and detailed explanation of the measurements. (author)
NGC1300 dynamics - II. The response models
Kalapotharakos, C.; Patsis, P. A.; Grosbøl, P.
2010-10-01
We study the stellar response in a spectrum of potentials describing the barred spiral galaxy NGC1300. These potentials have been presented in a previous paper and correspond to three different assumptions as regards the geometry of the galaxy. For each potential we consider a wide range of Ωp pattern speed values. Our goal is to discover the geometries and the Ωp supporting specific morphological features of NGC1300. For this purpose we use the method of response models. In order to compare the images of NGC1300 with the density maps of our models, we define a new index which is a generalization of the Hausdorff distance. This index helps us to find out quantitatively which cases reproduce specific features of NGC1300 in an objective way. Furthermore, we construct alternative models following a Schwarzschild-type technique. By this method we vary the weights of the various energy levels, and thus the orbital contribution of each energy, in order to minimize the differences between the response density and that deduced from the surface density of the galaxy, under certain assumptions. We find that the models corresponding to Ωp ~ 16 and 22 kms-1kpc-1 are able to reproduce efficiently certain morphological features of NGC1300, with each one having its advantages and drawbacks. Based on observations collected at the European Southern Observatory, Chile: programme ESO 69.A-0021. E-mail: ckalapot@phys.uoa.gr (CK); patsis@academyofathens.gr (PAP); pgrosbol@eso.org (PG)
International Nuclear Information System (INIS)
Dabli, Djamel
2010-01-01
Hadron-therapy is a cancer treatment method based on the use of heavy charged particles. The physical characteristics of these particles allow more precise targeting of tumours and offer higher biological efficiency than photons and electrons. This thesis addresses the problem of modelling the biological effects induced by such particles. One part of this work is devoted to the analysis of the Monte-Carlo simulation tool-kit 'Geant4' used to simulate the physical stage of the particle interactions with the biological medium. We evaluated the ability of 'Geant4' to simulate the microscopic distribution of energy deposition produced by charged particles and we compared these results with those of another simulation code dedicated to radiobiological applications. The other part of the work is dedicated to the study of two radiobiological models that are the LEM (Local Effect Model) based on an amorphous track structure approach and the MKM (Microdosimetric Kinetic Model) based on microdosimetric approach. A theoretical analysis of both models and a comparison of their concepts are presented. Then we focused on a detailed analysis of the microdosimetric model 'MKM'. Finally, we applied the MKM to reproduce the experimental results obtained at GANIL by irradiation of two tumour cell lines (cell line SCC61 and SQ20B) of different radiosensitivity with carbon and argon ions. (author)
Hadron showers in a highly granular calorimeter
Energy Technology Data Exchange (ETDEWEB)
Lutz, Benjamin
2010-11-15
identify the position of the first hard interaction in hadron showers is developed in this work. It is applied to measure hadron shower profiles without the fluctuations in the position of the first hard interaction and to estimate and correct for longitudinal leakage. Finally, different hadron simulation models are confronted with the measured data. The Geant4 based simulation of the test-beam is explained; the detector modelling and the systematic error assumptions are verified with electromagnetic showers. The studies comprise thirteen different Geant4 physics lists and six different hadron shower models. Both the description of the spatial shower development and the modelling of the detector response and the resolution are tested. (orig.)
Hadron showers in a highly granular calorimeter
International Nuclear Information System (INIS)
Lutz, Benjamin
2010-11-01
identify the position of the first hard interaction in hadron showers is developed in this work. It is applied to measure hadron shower profiles without the fluctuations in the position of the first hard interaction and to estimate and correct for longitudinal leakage. Finally, different hadron simulation models are confronted with the measured data. The Geant4 based simulation of the test-beam is explained; the detector modelling and the systematic error assumptions are verified with electromagnetic showers. The studies comprise thirteen different Geant4 physics lists and six different hadron shower models. Both the description of the spatial shower development and the modelling of the detector response and the resolution are tested. (orig.)
Simulation modeling and analysis in safety. II
International Nuclear Information System (INIS)
Ayoub, M.A.
1981-01-01
The paper introduces and illustrates simulation modeling as a viable approach for dealing with complex issues and decisions in safety and health. The author details two studies: evaluation of employee exposure to airborne radioactive materials and effectiveness of the safety organization. The first study seeks to define a policy to manage a facility used in testing employees for radiation contamination. An acceptable policy is one that would permit the testing of all employees as defined under regulatory requirements, while not exceeding available resources. The second study evaluates the relationship between safety performance and the characteristics of the organization, its management, its policy, and communication patterns among various functions and levels. Both studies use models where decisions are reached based on the prevailing conditions and occurrence of key events within the simulation environment. Finally, several problem areas suitable for simulation studies are highlighted. (Auth.)
System modeling and simulation at EBR-II
International Nuclear Information System (INIS)
Dean, E.M.; Lehto, W.K.; Larson, H.A.
1986-01-01
The codes being developed and verified using EBR-II data are the NATDEMO, DSNP and CSYRED. NATDEMO is a variation of the Westinghouse DEMO code coupled to the NATCON code previously used to simulate perturbations of reactor flow and inlet temperature and loss-of-flow transients leading to natural convection in EBR-II. CSYRED uses the Continuous System Modeling Program (CSMP) to simulate the EBR-II core, including power, temperature, control-rod movement reactivity effects and flow and is used primarily to model reactivity induced power transients. The Dynamic Simulator for Nuclear Power Plants (DSNP) allows a whole plant, thermal-hydraulic simulation using specific component and system models called from libraries. It has been used to simulate flow coastdown transients, reactivity insertion events and balance-of-plant perturbations
Argonne Bubble Experiment Thermal Model Development II
Energy Technology Data Exchange (ETDEWEB)
Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-07-01
This report describes the continuation of the work reported in “Argonne Bubble Experiment Thermal Model Development”. The experiment was performed at Argonne National Laboratory (ANL) in 2014. A rastered 35 MeV electron beam deposited power in a solution of uranyl sulfate, generating heat and radiolytic gas bubbles. Irradiations were performed at three beam power levels, 6, 12 and 15 kW. Solution temperatures were measured by thermocouples, and gas bubble behavior was observed. This report will describe the Computational Fluid Dynamics (CFD) model that was developed to calculate the temperatures and gas volume fractions in the solution vessel during the irradiations. The previous report described an initial analysis performed on a geometry that had not been updated to reflect the as-built solution vessel. Here, the as-built geometry is used. Monte-Carlo N-Particle (MCNP) calculations were performed on the updated geometry, and these results were used to define the power deposition profile for the CFD analyses, which were performed using Fluent, Ver. 16.2. CFD analyses were performed for the 12 and 15 kW irradiations, and further improvements to the model were incorporated, including the consideration of power deposition in nearby vessel components, gas mixture composition, and bubble size distribution. The temperature results of the CFD calculations are compared to experimental measurements.
An electron-hadron separator for digital sampling calorimeters
International Nuclear Information System (INIS)
Winter, K. de; Geiregat, D.; Vilain, P.; Wilquet, G.; Bergsma, F.; Binder, U.; Burkard, H.; Capone, A.; Ereditato, A.; Flegel, W.; Grote, H.; Nieuwenhuis, C.; Oeveras, H.; Palladino, V.; Panman, J.; Piredda, G.; Winter, K.; Zacek, G.; Zacek, V.; Bauche, T.; Beyer, R.; Blobel, V.; Buesser, F.W.; Foos, C.; Gerland, L.; Niebergall, F.; Staehelin, P.; Tadsen, A.; Gorbunov, P.; Grigoriev, E.; Khovansky, V.; Maslennikov, A.; Rosanov, A.; Lippich, W.; Nathaniel, A.; Staude, A.; De Pedis, D.; Di Capua, E.; Dore, U.; Loverre, P.F.; Rambaldi-Frenkel, A.; Santacesaria, R.; Zanello, D.
1989-01-01
A fast and effective algorithm for electromagnetic and hadronic shower separation has been developed for the digital sampling calorimeter of the CHARM II experiment. It is based on a generalization of the minimal spanning tree concept and can be easily applied to other existing calorimeters. In this particular application, which requires the highest efficiency for retaining electromagnetic showers, one gets, for 99% efficiency, a rejection factor of the order of 100 for hadronic showers. (orig.)
Hadron Therapy for Cancer Treatment
International Nuclear Information System (INIS)
Lennox, Arlene
2003-01-01
The biological and physical rationale for hadron therapy is well understood by the research community, but hadron therapy is not well established in mainstream medicine. This talk will describe the biological advantage of neutron therapy and the dose distribution advantage of proton therapy, followed by a discussion of the challenges to be met before hadron therapy can play a significant role in treating cancer. A proposal for a new research-oriented hadron clinic will be presented.
International Nuclear Information System (INIS)
Latham, T.E.
2014-01-01
We present recent results from the analysis of hadronic decays of B s 0 mesons at LHCb detector. The analyses use the data sample collected in 2011, which correspond to an integrated luminosity of 1.0 fb -1 . A large variety of different decays are being studied in order to probe for signs of physics beyond the Standard Model. The statistics available in the 2011 data sample already allow sophisticated analysis techniques, such as the Dalitz-plot analysis and the angular analysis to be employed
Scalar strong interaction hadron theory
Hoh, Fang Chao
2015-01-01
The scalar strong interaction hadron theory, SSI, is a first principles' and nonlocal theory at quantum mechanical level that provides an alternative to low energy QCD and Higgs related part of the standard model. The quark-quark interaction is scalar rather than color-vectorial. A set of equations of motion for mesons and another set for baryons have been constructed. This book provides an account of the present state of a theory supposedly still at its early stage of development. This work will facilitate researchers interested in entering into this field and serve as a basis for possible future development of this theory.
DEFF Research Database (Denmark)
Andersen, Thomas Lykke; Frigaard, Peter
This report present the results of 2D physical model tests carried out in the shallow wave flume at Dept. of Civil Engineering, Aalborg University (AAU), on behalf of Energy E2 A/S part of DONG Energy A/S, Denmark. The objective of the tests was: to investigate the combined influence of the pile...... diameter to water depth ratio and the wave hight to water depth ratio on wave run-up of piles. The measurements should be used to design access platforms on piles....
Confinement and quark structure of light hadrons
International Nuclear Information System (INIS)
Efimov, G.V.; Ivanov, M.A.
1988-01-01
We present a quark confinement model (QCM) for the description of the low-energy physics of light hadrons (mesons and baryons). The model is based on two hypotheses. First, the quark confinement is realized as averaging over vacuum gluon fields which are believed to provide the confinement of any colour objects. Second, hadrons are treated as collective colourless excitations of quark-gluon interactions. The description of strong, electromagnetic and weak interactions of mesons and baryons at the low energy is given from a unique point of view
Hadron chemistry in heavy ion collisions
International Nuclear Information System (INIS)
Montvay, I.; Zimanyi, J.
1978-06-01
In the models for energetic heavy ion reactions it is assumed that during the reaction a hot and dense nuclear matter, a fireball is formed from all or a part of nucleons of the target and projectile nuclei. The process is similar to the chemical processes leading to dynamical equilibrium. The relaxation times necessary to establish ''chemical'' equilibrium among different hadrons in hot, dense hadronic matter is deducted in a statistical model. Consequences for heavy ion collisions are discussed. The possibility of Bose-Einstein pion condensation around the break-up time of the nuclear fireball is pointed out. (D.P.)
Hadronic interactions in the MINOS detectors
Energy Technology Data Exchange (ETDEWEB)
Kordosky, Michael Alan [Univ. of Texas, Austin, TX (United States)
2004-08-01
MINOS, the Main Injector Neutrino Oscillation Search, will study neutrino flavor transformations using a Near detector at the Fermi National Accelerator Laboratory and a Far detector located in the Soudan Underground Laboratory in northern Minnesota. The MINOS collaboration also constructed the CalDet (calibration detector), a smaller version of the Near and Far detectors, to determine the topological and signal response to hadrons, electrons and muons. The detector was exposed to test-beams in the CERN Proton Synchrotron East Hall during 2001-2003, where it collected events at momentum settings between 200 MeV/c and 10 GeV/c. In this dissertation we present results of the CalDet experiment, focusing on the topological and signal response to hadrons. We briefly describe the MINOS experiment and its iron-scintillator tracking-sampling calorimters as a motivation for the CalDet experiment. We discuss the operation of the CalDet in the beamlines as well as the trigger and particle identification systems used to isolate the hadron sample. The method used to calibrate the MINOS detector is described and validated with test-beam data. The test-beams were simulated to model the muon flux, energy loss upstream of the detector and the kaon background. We describe the procedure used to discriminate between pions and muons on the basis of the event topology. The hadron samples were used to benchmark the existing GEANT3 based hadronic shower codes and determine the detector response and resolution for pions and protons. We conclude with comments on the response to single hadrons and to neutrino induced hadronic showers.
International Nuclear Information System (INIS)
Johnson, R.C.
1980-01-01
High energy and small momentum transfer 2 'yields' 2 hadronic scattering processes are described in the physical framework of particle exchange. Particle production in high energy collisions is considered with emphasis on the features of inclusive reactions though with some remarks on exclusive processes. (U.K.)
Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G
1996-01-01
From 64492 selected \\tau-pair events, produced at the Z^0 resonance, the measurement of the tau decays into hadrons from a global analysis using 1991, 1992 and 1993 ALEPH data is presented. Special emphasis is given to the reconstruction of photons and \\pi^0's, and the removal of fake photons. A detailed study of the systematics entering the \\pi^0 reconstruction is also given. A complete and consistent set of tau hadronic branching ratios is presented for 18 exclusive modes. Most measurements are more precise than the present world average. The new level of precision reached allows a stringent test of \\tau-\\mu universality in hadronic decays, g_\\tau/g_\\mu \\ = \\ 1.0013 \\ \\pm \\ 0.0095, and the first measurement of the vector and axial-vector contributions to the non-strange hadronic \\tau decay width: R_{\\tau ,V} \\ = \\ 1.788 \\ \\pm \\ 0.025 and R_{\\tau ,A} \\ = \\ 1.694 \\ \\pm \\ 0.027. The ratio (R_{\\tau ,V} - R_{\\tau ,A}) / (R_{\\tau ,V} + R_{\\tau ,A}), equal to (2.7 \\pm 1.3) \\ \\%, is a measure of the importance of Q...
Eytier, Jean-Louis
2009-01-01
Qu'aurait-il proposé comme solutions face aux déboires du LHC, le grand collisionneur du hadrons du CERN, arrêté peu après son démarrage à l'automne 2008? Lucien Edmond André Montanet était un des grands de la physique des particules. (2 pages)
Indian Academy of Sciences (India)
manifestly the symmetries of the underlying theory of strong interactions, i.e. ..... Note that such a picture, in which the self-energies of hadrons are generated by ..... An experimental verification of this prediction would be a major step forward in.
Hirstius, Andreas
2008-01-01
Plans for dealing with the torrent of data from the Large Hadron Collider's detectors have made the CERN particle-phycis lab, yet again, a pioneer in computing as well as physics. The author describes the challenges of processing and storing data in the age of petabyt science. (4 pages)
2007-01-01
"In the spring 2008, the Large Hadron Collider (LHC) machine at CERN (the European Particle Physics laboratory) will be switched on for the first time. The huge machine is housed in a circular tunnel, 27 km long, excavated deep under the French-Swiss border near Geneva." (1,5 page)
Burgess, Cliff; Moore, Guy
2012-04-01
List of illustrations; List of tables; Preface; Acknowledgments; Part I. Theoretical Framework: 1. Field theory review; 2. The standard model: general features; 3. Cross sections and lifetimes; Part II. Applications: Leptons: 4. Elementary boson decays; 5. Leptonic weak interactions: decays; 6. Leptonic weak interactions: collisions; 7. Effective Lagrangians; Part III. Applications: Hadrons: 8. Hadrons and QCD; 9. Hadronic interactions; Part IV. Beyond the Standard Model: 10. Neutrino masses; 11. Open questions, proposed solutions; Appendix A. Experimental values for the parameters; Appendix B. Symmetries and group theory review; Appendix C. Lorentz group and the Dirac algebra; Appendix D. ξ-gauge Feynman rules; Appendix E. Metric convention conversion table; Select bibliography; Index.
PEP-II vacuum system pressure profile modeling using EXCEL
International Nuclear Information System (INIS)
Nordby, M.; Perkins, C.
1994-06-01
A generic, adaptable Microsoft EXCEL program to simulate molecular flow in beam line vacuum systems is introduced. Modeling using finite-element approximation of the governing differential equation is discussed, as well as error estimation and program capabilities. The ease of use and flexibility of the spreadsheet-based program is demonstrated. PEP-II vacuum system models are reviewed and compared with analytical models
Gluon bremstrahlung effects in large P/sub perpendicular/ hadron-hadron scattering
International Nuclear Information System (INIS)
Fox, G.C.; Kelly, R.L.
1982-02-01
We consider effects of parton (primarily gluon) bremstrahlung in the initial and final states of high transverse momentum hadron-hadron scattering. Monte Carlo calculations based on conventional QCD parton branching and scattering processes are presented. The calculations are carried only to the parton level in the final state. We apply the model to the Drell-Yan process and to high transverse momentum hadron-hadron scattering triggered with a large aperture calorimeter. We show that the latter triggers are biased in that they select events with unusually large bremstrahlung effects. We suggest that this trigger bias explains the large cross section and non-coplanar events observed in the NA5 experiment at the SPS
Hadronization of QCD and effective interactions
International Nuclear Information System (INIS)
Frank, M.R.
1994-01-01
An introductory treatment of hadronization through functional integral calculus and bifocal Bose fields is given. Emphasis is placed on the utility of this approach for providing a connection between QCD and effective hadronic field theories. The hadronic interactions obtained by this method are nonlocal due to the QCD substructure, yet, in the presence of an electromagnetic field, maintain the electromagnetic gauge invariance manifest at the quark level. A local chiral model which is structurally consistent with chiral perturbation theory is obtained through a derivative expansion of the nonlocalities with determined, finite coefficients. Tree-level calculations of the pion form factor and π - π scattering, which illustrate the dual constituent-quark-chiral-model nature of this approach, are presented
Inelastic hadron reactions using a streamer chamber triggered by a single-arm spectrometer
2002-01-01
This experiment will investigate hard hadron-hadron collisions where a large fraction of the total energy is carried off at large angles with respect to the incident beam direction. The measurements will be done in the energy range of 200-400 GeV and with various hadrons ($\\pi^{\\pm}, K^{\\pm}, p, \\bar{p}$) incident on a liquid-hydrogen target. \\\\ \\\\The following questions will be investigated: \\\\ \\\\i) Is there a scaling law in hard hadron-hadron collisions which is similar to the scaling laws observed in lepton-hadron and $e^{+}e^{-}$ collisions? \\\\ ii) What do the multiparticle final states look like? Are there jets and if so do they reflect the parton structure of hadrons? Do the final states produced in deep inelastic hadron-hadron scattering look similar to those produced in deep inelastic lepton-hadron scattering? \\\\ iii) Are heavy objects and/or new quantum numbers produced in hard hadron-hadron collisions? \\\\ \\\\The apparatus comprises a vertex magnet (1 m gap, 2 m diameter, 15 kG) with a 30 cm long hyd...
Statistical fluctuations and correlations in hadronic equilibrium systems
Energy Technology Data Exchange (ETDEWEB)
Hauer, Michael
2010-06-17
This thesis is dedicated to the study of fluctuation and correlation observables of hadronic equilibrium systems. The statistical hadronization model of high energy physics, in its ideal, i.e. non-interacting, gas approximation is investigated in different ensemble formulations. The hypothesis of thermal and chemical equilibrium in high energy interaction is tested against qualitative and quantitative predictions. (orig.)
Triggering on hadronic tau decays: ATLAS meets the challenge
Indian Academy of Sciences (India)
Hadronic tau decays play a crucial role in taking Standard Model (SM) measurements as well as in the search for physics beyond the SM. However, hadronic tau decays are difficult to identify and trigger on due to their resemblance to QCD jets. Given the large production crosssection of QCD processes, designing and ...
Statistical fluctuations and correlations in hadronic equilibrium systems
International Nuclear Information System (INIS)
Hauer, Michael
2010-01-01
This thesis is dedicated to the study of fluctuation and correlation observables of hadronic equilibrium systems. The statistical hadronization model of high energy physics, in its ideal, i.e. non-interacting, gas approximation is investigated in different ensemble formulations. The hypothesis of thermal and chemical equilibrium in high energy interaction is tested against qualitative and quantitative predictions. (orig.)
Hadron physics from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Schaefer, Andreas [Regensburg Univ. (Germany). Inst. for Theoretical Physics
2016-11-01
Particle physics experiments at modern high luminosity particle accelerators achieve orders of magnitude higher count rates than what was possible ten or twenty years ago. This extremely large statistics allows to draw far reaching conclusions even from minute signals, provided that these signals are well understood by theory. This is, however, ever more difficult to achieve. Presently, technical and scientific progress in general and experimental progress in particle physics in particular, shows typically an exponential growth rate. For example, data acquisition and analysis are, among many other factor, driven by the development of ever more efficient computers and thus by Moore's law. Theory has to keep up with this development by also achieving an exponential increase in precision, which is only possible using powerful computers. This is true for both types of calculations, analytic ones as, e.g., in quantum field perturbation theory, and purely numerical ones as in Lattice QCD. As stated above such calculations are absolutely indispensable to make best use of the extremely costly large particle physics experiments. Thus, it is economically reasonable to invest a certain percentage of the cost of accelerators and experiments in related theory efforts. The basic ideas behind Lattice QCD simulations are the following: Because quarks and gluons can never be observed individually but are always ''confined'' into colorless hadrons, like the proton, all quark-gluon states can be expressed in two different systems of basis states, namely in a quark-gluon basis and the basis of hadron states. The proton, e.g., is an eigenstate of the latter, a specific quark-gluon configuration is part of the former. In the quark-gluon basis a physical hadron, like a proton, is given by an extremely complicated multi-particle wave function containing all effects of quantum fluctuations. This state is so complicated that it is basically impossible to model it
AUTHOR|(SzGeCERN)793139; Roloff, Philipp Gerhard; Strom, Lars Rickard; Weber, Matthias Artur
2017-01-01
A study of the W and Z separation was performed for the CLIC_ILD and the CLICdet detector models for the proposed Compact Linear Collider (CLIC). Comparisons were done for fully-hadronic WW and ZZ events at the collision energies of 1.4 and 3 TeV. Particle flow objects are reconstructed using a full simulation of the events including relevant beam-induced background processes. Several different collections of particles, with varying level of background suppression, were compared for each of the detector models and optimal jet clustering parameters were found in each case, resulting in the best separation of the W and Z mass peaks. The CLICdet detector model performs similar to CLIC_ILD with an achieved jet mass separation of around 1.6 $\\sigma$ at 1.4 TeV and 1.3 $\\sigma$ at 3 TeV. For both detector models we achieve a better separation at 1.4 TeV when comparing dijet masses rather than large-R jet masses. At 3 TeV jets with a radius around R=0.5 perform similarly well as dijets.
Energy Technology Data Exchange (ETDEWEB)
Delsart, Pierre Antoine [Claude Bernard Univ. Lyon (France)
2003-10-13
This thesis was realized in collaboration with the "theory'' group and the "D0" group of IPNL. Within D0 we have worked on a component of the calibration of the detector's calorimeter : the intercalibration. Using the fact the physics is $\\phi$-symmetric in D0, we created and applied statistical methods for a relative calibration of the $\\phi$-symmetric parts of the calorimeter. Work on particle physics concerned the two Higgs doublet model. In such models leptonic number violation is possible : we have simulated the $H^0/A^0 \\to \\tau \\mu$ signal in order to study the discovery potential and the constraints on the coupling responsible for this decay.
International Nuclear Information System (INIS)
Batunin, A.V.; Smirnov, A.Yu.
1985-01-01
The role of states with hidden colour inside a nucleus in leptoproduction processes (at the example of J/psi-meson) production is investigated. A concrete production mechanism is proposed, appealing to the dual parton model of hadron-hadron interactions. Comparison with experiment is made
A comprehensive analysis of hadronic b → s transitions in a family non-universal Z′ model
International Nuclear Information System (INIS)
Chang, Qin; Li, Xin-Qiang; Yang, Ya-Dong
2014-01-01
Motivated by the latest improved measurements of B-meson decays, we make a comprehensive analysis of the impact of a family non-universal Z ′ boson on B s − B-bar s mixing and two-body hadronic B-meson decays, all being characterized by the quark-level b→s transition. Explicitly 22 decay modes and the related 52 observables are considered, and some interesting correlations between them are also carefully examined. Firstly, the allowed oases of b−s−Z ′ coupling parameters |B sb L,R | and ϕ s L,R are extracted from B s − B-bar s mixing. Then, in the ‘SM limit’ (i.e., no new types of Z ′ -induced four-quark operators arise compared to the SM case), we study the Z ′ effects on B→πK, πK ∗ and ρK decays. It is found that a new weak phase ϕ s L ∼−90 ∘ is crucial for resolving the observed ‘πK CP puzzle’ and the allowed cases of the other Z ′ coupling parameters are also strongly restricted. Moreover, the Z ′ effects on B-bar s →KK, KK ∗ and π 0 ϕ decays, being induced by the same quark-level b→sq q-bar (q=u,d) transitions, are also investigated. In particular, it is found that the decay B-bar s →π 0 ϕ, once measured, would play a key role in revealing the observed ‘πK CP puzzle’ and probing possible new physics hints. Finally, to check the non-universality of Z ′ couplings to light-quark pairs, we have studied the B→ϕK decays in detail and found that the left-handed s−s−Z ′ coupling is different from the d−d−Z ′ one, which is due to the large A CP dir (B − →ϕK − ) reported by the BaBar Collaboration. (paper)
Gluon bremsstrahlung and elastic scattering of hadrons
International Nuclear Information System (INIS)
Povh, B.
2001-01-01
The differential and the total cross sections in high energy hadron-proton interactions give a beautiful insight in the low Q 2 structure of the nucleon. The cross section is composed of two parts: a large energy independent part corresponding to the interaction of the valence quark with the target without gluon radiation and an energy dependent part caused by gluon bremsstrahlung. The gluons are located at small transverse distances of about 0.3 fm from the valence quarks. The model with two scales, the size of the hadron (R 2 ∼ 1 fm 2 ) and the size of the gluonic cloud (r 0 2 ∼ 0.1 fm 2 ), correctly predicts the total and the differential cross sections and the behaviour of diffractive dissociation in hadronic and deep inelastic events. (orig.)
Physics at Hadronic Colliders (4/4)
CERN. Geneva
2008-01-01
Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)
Physics at Hadronic Colliders (1/4)
CERN. Geneva
2008-01-01
Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)
Physics at Hadronic Colliders (2/4)
CERN. Geneva
2008-01-01
Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)
Physics at Hadronic Colliders (3/4)
CERN. Geneva
2008-01-01
Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)
The Ways of Four-Quark Hadrons
CERN. Geneva
2014-01-01
Ten years after the discovery of the X(3872) we can assert that a number of exotic four-quark hadrons with hidden charm and beauty have been discovered, the most recent, Z(3900), found by BES in 2013, being among the top-striking ones. However, ten years have not been enough to dispel the controversy about their inner structure, with two body hadron molecules and compact multiquark states being the withstanding antipodal models. In this seminar I will review the status of the field, presenting both the experimental facts and the theoretical pictures attempting to interpret them.
Computing Models of CDF and D0 in Run II
International Nuclear Information System (INIS)
Lammel, S.
1997-05-01
The next collider run of the Fermilab Tevatron, Run II, is scheduled for autumn of 1999. Both experiments, the Collider Detector at Fermilab (CDF) and the D0 experiment are being modified to cope with the higher luminosity and shorter bunchspacing of the Tevatron. New detector components, higher event complexity, and an increased data volume require changes from the data acquisition systems up to the analysis systems. In this paper we present a summary of the computing models of the two experiments for Run II
Computing Models of CDF and D0 in Run II
International Nuclear Information System (INIS)
Lammel, S.
1997-01-01
The next collider run of the Fermilab Tevatron, Run II, is scheduled for autumn of 1999. Both experiments, the Collider Detector at Fermilab (CDF) and the D0 experiment are being modified to cope with the higher luminosity and shorter bunch spacing of the Tevatron. New detector components, higher event complexity, and an increased data volume require changes from the data acquisition systems up to the analysis systems. In this paper we present a summary of the computing models of the two experiments for Run II
Modeling Fe II Emission and Revised Fe II (UV) Empirical Templates for the Seyfert 1 Galaxy I Zw 1
Bruhweiler, F.; Verner, E.
2008-03-01
We use the narrow-lined broad-line region (BLR) of the Seyfert 1 galaxy, I Zw 1, as a laboratory for modeling the ultraviolet (UV) Fe II 2100-3050 Å emission complex. We calculate a grid of Fe II emission spectra representative of BLR clouds and compare them with the observed I Zw 1 spectrum. Our predicted spectrum for log [nH/(cm -3) ] = 11.0, log [ΦH/(cm -2 s-1) ] = 20.5, and ξ/(1 km s-1) = 20, using Cloudy and an 830 level model atom for Fe II with energies up to 14.06 eV, gives a better fit to the UV Fe II emission than models with fewer levels. Our analysis indicates (1) the observed UV Fe II emission must be corrected for an underlying Fe II pseudocontinuum; (2) Fe II emission peaks can be misidentified as that of other ions in active galactic nuclei (AGNs) with narrow-lined BLRs possibly affecting deduced physical parameters; (3) the shape of 4200-4700 Å Fe II emission in I Zw 1 and other AGNs is a relative indicator of narrow-line region (NLR) and BLR Fe II emission; (4) predicted ratios of Lyα, C III], and Fe II emission relative to Mg II λ2800 agree with extinction corrected observed I Zw 1 fluxes, except for C IV λ1549 (5) the sensitivity of Fe II emission strength to microturbulence ξ casts doubt on existing relative Fe/Mg abundances derived from Fe II (UV)/Mg II flux ratios. Our calculated Fe II emission spectra, suitable for BLRs in AGNs, are available at http://iacs.cua.edu/people/verner/FeII. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 05-26555.
Correlations in hadron-hadron interactions at high energy
International Nuclear Information System (INIS)
Nguyen Huu Khanh
1978-01-01
Some main features of the experimental results on the correlations in hadron-hadron interactions at high energy are considered. Particular attention is paid to the long-range correlation, short-range correlation and Bose-Einstein effect. Long-range correlations are confirmed by the variation of the number of charged particles produced in the final state depending on energy, violation of Koba-Nielsen- Olesen scaling and the analysis of correlation betWeen the numbers of charged particles emitted in the forward and backward hemispheres. Short-range correlations are discussed from the point of view of ISR pp, 195 GeV/c pN and 32 GeV/c k + p experiments. Bose-Einstein effects are studied up to now only between pions. Pions are not produced directly but from the decay of heavier objects. Some experimental results seem to support the evidence for dynamical long-range correlations. Most of the data are compatible with the independent cluster model
Triggering on hadronic tau decays: ATLAS meets the challenge
Scarcella, M J; The ATLAS collaboration
2011-01-01
Hadronic tau decays play a crucial role in taking Standard Model measurements as well as in the search for physics beyond the Standard Model. However, hadronic tau decays are difficult to identify and trigger on due to their resemblance to QCD jets. Given the large production cross section of QCD processes, designing and operating a trigger system with the capability to efficiently select hadronic tau decays, while maintaining the rate within the bandwidth limits, is a difficult challenge. This contribution will summarize the status and performance of the ATLAS tau trigger system during the 2011 data taking period, emphasizing the key elements of the online selection. Different methods that have been explored to obtain the trigger efficiency curves from data will be shown. Finally, the status of the measurements, which include hadronic tau decays in the final state, will be summarized. In light of the vast statistics collected in 2011, future prospects for triggering on hadronic tau decays in this exciting ne...
SDSS-II: Determination of shape and color parameter coefficients for SALT-II fit model
Energy Technology Data Exchange (ETDEWEB)
Dojcsak, L.; Marriner, J.; /Fermilab
2010-08-01
In this study we look at the SALT-II model of Type IA supernova analysis, which determines the distance moduli based on the known absolute standard candle magnitude of the Type IA supernovae. We take a look at the determination of the shape and color parameter coefficients, {alpha} and {beta} respectively, in the SALT-II model with the intrinsic error that is determined from the data. Using the SNANA software package provided for the analysis of Type IA supernovae, we use a standard Monte Carlo simulation to generate data with known parameters to use as a tool for analyzing the trends in the model based on certain assumptions about the intrinsic error. In order to find the best standard candle model, we try to minimize the residuals on the Hubble diagram by calculating the correct shape and color parameter coefficients. We can estimate the magnitude of the intrinsic errors required to obtain results with {chi}{sup 2}/degree of freedom = 1. We can use the simulation to estimate the amount of color smearing as indicated by the data for our model. We find that the color smearing model works as a general estimate of the color smearing, and that we are able to use the RMS distribution in the variables as one method of estimating the correct intrinsic errors needed by the data to obtain the correct results for {alpha} and {beta}. We then apply the resultant intrinsic error matrix to the real data and show our results.
Lavender, Gemma
2018-01-01
What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the worlds largest particle smasher the Large Hadron Collider at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerators greatest discoveries from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.
International Nuclear Information System (INIS)
Yamazaki, Toshimitsu
1990-01-01
The Japanese Hadron Project (JHP) is aimed at producing various kinds of unstable secondary beams based on high-intensity protons from a new accelerator complex. The 1 GeV protons, first produced from a 1 GeV linac, are transferred to a compressor/stretcher ring, where a sharply-pulsed beam or a stretched continuous beam will be produced. The pulsed beam will be used for a pulsed muon source (M arena) and a spallation neutron source (N arena). A part of the proton beam will be used to produce unstable nuclei, which will be accelerated to several MeV/nucleon (E arena). The purpose and impact of JHP will be described in view of future applications of hadronic beams to nuclear energy and material science. (author)
Czech Academy of Sciences Publication Activity Database
Adloff, C.; Blaising, J.J.; Chefdeville, M.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Denis; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav
2014-01-01
Roč. 9, Jul (2014), s. 1-24 ISSN 1748-0221 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : hadronic calorimeter s * hadronic showers * hadronic physics models * hilicon photomultiplier Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.399, year: 2014
International Nuclear Information System (INIS)
Roser, T.
1994-01-01
There were four sessions on Hadron Beams and Accelerators with 7 talks on Siberian Snakes and spin rotators, 3 talks on polarization build-up of unpolarized beams in storage rings and 5. 9, and 3 talks on low, medium, and high energy polarimeters, respectively. In this paper I will briefly describe a few highlights from these sessions, giving emphasis to topics which I think will play an important role in the future
International Nuclear Information System (INIS)
Roser, T.
1995-01-01
There were four sessions on Hadron Beams and Accelerators with 7 talks on Siberian Snakes and spin rotators, 3 talks on polarization build-up of unpolarized beams in storage rings and 5, 9, and 3 talks on low, medium, and high energy polarimeters, respectively. In this paper I will briefly describe a few highlights from these sessions, giving emphasis to topics which I think will play an important role in the future. copyright 1995 American Institute of Physics
Juettner Fernandes, Bonnie
2014-01-01
What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Includes glossary, websites, and bibliography for further reading. Perfect for STEM connections. Aligns to the Common Core State Standards for Language Arts. Teachers' Notes available online.
Parton distribution in relativistic hadrons
International Nuclear Information System (INIS)
Kopeliovich, B.Z.; Lapidus, L.I.; Zamolodchikov, Al.B.
1979-01-01
The distribution in the slow-parton number in the relativistic hadron is considered as a function of its rapidity (y). Neglecting corrections due to the tarton chain recombination the equation is derived and its explicit solution is found. It describes this distribution depending on the initial distribution at y approximately 1. Comparison with the reggeon diagrams results in relations between the parton model and the regaeon field theory parameters. The interpretation of the cutting rules in the framework of the parton model is presented. The numerical estimation of the parton model parameters is performed. It is shown that the slow-parton density corresponding to accessible energies seems to be close to the saturated density. Therefore, the enhanced graphs contributions turn out to be of considerable importance
Leading Hadron Production at HERA
Directory of Open Access Journals (Sweden)
Buniatyan Armen
2013-06-01
Full Text Available Data from the recent measurements of very forward baryon and photon production with the H1 and ZEUS detectors at electron-proton collider HERA are presented and compared to the theoretical calculations and Monte Carlo models. Results are presented of the production of leading protons, neutrons and photons in deep inelastic scattering (ep → e' pX, ep → e'nX, ep → e'γX as well as the leading neutron production in the photoproduction of dijets (ep → ejjXn. The forward baryon and photon results from the H1 and ZEUS Experiments are compared also with the models of the hadronic interactions of high energy Cosmic Rays. The sensitivity of the HERA data to the differences between the models is demonstrated.
Directory of Open Access Journals (Sweden)
S. Mohammad Moosavi Nejad
2017-08-01
Full Text Available In recent years, searches for the light and heavy charged Higgs bosons have been done by the ATLAS and the CMS collaborations at the Large Hadron Collider (LHC in proton–proton collision. Nevertheless, a definitive search is a program that still has to be carried out at the LHC. The experimental observation of charged Higgs bosons would indicate physics beyond the Standard Model. In the present work, we study the scaled-energy distribution of bottom-flavored mesons (B inclusively produced in polarized top quark decays into a light charged Higgs boson and a massless bottom quark at next-to-leading order in the two-Higgs-doublet model; t(↑→bH+→BH++X. This spin-dependent energy distribution is studied in a specific helicity coordinate system where the polarization vector of the top quark is measured with respect to the direction of the Higgs momentum. The study of these energy distributions could be considered as a new channel to search for the charged Higgs bosons at the LHC. For our numerical analysis and phenomenological predictions, we restrict ourselves to the unexcluded regions of the MSSM mH+−tanβ parameter space determined by the recent results of the CMS [13] and ATLAS [14] collaborations.
Particle theory and intense hadron facilities
International Nuclear Information System (INIS)
Ng, J.N.
1989-05-01
A brief overview of particle physics that can be done at an intense hadron facility (IHF) is given. The emphasis is placed on testing the standard model, light Higgs boson searches and CP violation, which are areas an IHF can do especially well
Diquark fragmentation in leptoproduction of hadrons
International Nuclear Information System (INIS)
Beavis, D.; Desai, B.R.
1981-08-01
In the analysis of the leptoproduction data for the charge ratios of hadrons, the Sukhatme, Lassila and Orava (SLO) model for diquark fragmentation is shown to be consistent with the hypothesis of a diquark acting as a single unit. The baryon contribution to the charge ratio, ignored earlier by SLO, makes a significant effect. (author)
Production of strange particles in hadronization processes
International Nuclear Information System (INIS)
Hofmann, W.
1987-08-01
Strange particles provide an important tool for the study of the color confinement mechanisms involved in hadronization processes. We review data on inclusive strange-particle production and on correlations between strange particles in high-energy reactions, and discuss phenomenological models for parton fragmentation. 58 refs., 24 figs
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J.; Deshpande, Abhay L.; Gao, Haiyan; McKeown, Robert D.; Meyer, Curtis A.; Meziani, Zein-Eddine; Milner, Richard G.; Qiu, Jianwei; Richards, David G.; Roberts, Craig D.
2015-02-26
This White Paper presents the recommendations and scientific conclusions from the Town Meeting on QCD and Hadronic Physics that took place in the period 13-15 September 2014 at Temple University as part of the NSAC 2014 Long Range Planning process. The meeting was held in coordination with the Town Meeting on Phases of QCD and included a full day of joint plenary sessions of the two meetings. The goals of the meeting were to report and highlight progress in hadron physics in the seven years since the 2007 Long Range Plan (LRP07), and present a vision for the future by identifying the key questions and plausible paths to solutions which should define the next decade. The introductory summary details the recommendations and their supporting rationales, as determined at the Town Meeting on QCD and Hadron Physics, and the endorsements that were voted upon. The larger document is organized as follows. Section 2 highlights major progress since the 2007 LRP. It is followed, in Section 3, by a brief overview of the physics program planned for the immediate future. Finally, Section 4 provides an overview of the physics motivations and goals associated with the next QCD frontier: the Electron-Ion-Collider.
Hadronization, spin and lifetimes
International Nuclear Information System (INIS)
Grossman, Yuval; Nachshon, Itay
2008-01-01
Measurements of lifetimes can be done in two ways. For very short lived particles, the width can be measured. For long lived ones, the lifetime can be directly measured, for example, using a displaced vertex. Practically, the lifetime cannot be extracted for particles with intermediate lifetimes. We show that for such cases information about the lifetime can be extracted for heavy colored particles that can be produced with known polarization. For example, a t-like particle with intermediate lifetime hadronizes into a superposition of the lowest two hadronic states, T* and T (the equivalent of B* and B). Depolarization effects are governed by time scales that are much longer than the hadronization time scale, Λ QCD -1 . After a time of order 1/Δm, with Δm≡m(T*)-m(T), half of the initial polarization is lost. The polarization is totally lost after a time of order 1/Γ γ , with Γ γ = Γ(T* → Tγ). Thus, by comparing the initial and final polarization, we get information on the particle's lifetime.
Superclusters and hadronic multiplicity distributions
International Nuclear Information System (INIS)
Shih, C.C.; Carruthers, P.
1986-01-01
The multiplicity distribution is expressed in terms of supercluster production in hadronic processes at high energy. This process creates unstable clusters at intermediate stages and hadrons in final stage. It includes Poisson-transform distributions (with the partially coherent distribution as a special case) and is very flexible for phenomenological analyses. The associated Koba, Nielson, and Olesen limit and the behavior of cumulant moments are analyzed in detail for finite and/or infinite cluster size and particle size per cluster. In general, a supercluster distribution does not need to be equivalent to a negative binomial distribution to fit experimental data well. Furthermore, the requirement of such equivalence leads to many solutions, in which the average size of the cluster is not logarithmic: e.g., it may show a power behavior instead. Superclustering is defined as a two-or multi-stage process underlying observed global multiplicity distributions. At the first stage of the production process, individual clusters are produced according to a given statistical law. For example, the clustering distribution may be described by partially coherent (oreven sub-Poissonian distribution models. At the second stage, the clusters are considered as the sources of particle production. The corresponding distribution may then be as general as the clustering distribution just mentioned. 8 refs
The role of hadron resonances in hot hadronic matter
Energy Technology Data Exchange (ETDEWEB)
Goity, Jose [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hampton Univ., Hampton, VA (United States)
2017-02-01
Hadron resonances can play a significant role in hot hadronic matter. Of particular interest for this workshop are the contributions of hyperon resonances. The question about how to quantify the effects of resonances is here addressed. In the framework of the hadron resonance gas, the chemically equilibrated case, relevant in the context of lattice QCD calculations, and the chemically frozen case relevant in heavy ion collisions are discussed.
Charged Hadron Properties in Background Electric Fields
International Nuclear Information System (INIS)
Detmold, William; Tiburzi, Brian C.; Walker-Loud, Andre
2010-01-01
We report on a lattice calculation demonstrating a novel new method to extract the electric polarizability of charged pseudo-scalar mesons by analyzing two point correlation functions computed in classical background electric fields. A staple component of any electrodynamics or quantum mechanics course is the electric polarizability. Neutral material immersed in a weak external field polarizes, internally setting up an electric dipole moment, aligned so as to minimize the energy. At the atomic level, the electron clouds are distorted creating these microscopic dipole moments. The same process occurs at the hadronic level but the polarization effects are now constrained by the strong force. Polarizabilities of these bound QCD states can be viewed as a distortion of the charged pion cloud of a given hadron. One can use lattice QCD to non-perturbatively compute the quark and gluon interactions in the presence of background electric (or magnetic) fields. For sufficiently weak background fields, the low energy properties of the hadrons can be rigorously computed using effective field theory. With this treatment, a picture of hadrons emerges from chiral dynamics: that of a hadronic core surrounded by a pseudoscalar meson cloud. As some pseudoscalar mesons are charged, polarizabilities of hadrons encode the stiffness of the charged meson cloud (as well as that of the core). The form of pseudoscalar meson polarizabilities is consequently strongly constrained by chiral dynamics. However, beyond the leading order, the results depend upon essentially unknown low-energy constants, which must currently be estimated in a model-dependent fashion. In the case of the charged pion, the experimental measurement of the polarizability has proven difficult, both in the original measurement as well as the most recent published result. Currently, there is a 2-3 sigma discrepancy between the two-loop cPT prediction and the measured charged pion polarizability. New results with higher
Abdel-Waged, Khaled; Uzhinskii, V V
2011-01-01
We describe how various hadronic cascade models, which are implemented in the GEANT4 toolkit, describe proton and charged pion transverse momentum spectra from p + Cu and Pb collisions at 3, 8, and 15 GeV/c, recently measured in the hadron production (HARP) experiment at CERN. The Binary, ultrarelativistic quantum molecular dynamics (UrQMD) and modified FRITIOF (FTF) hadronic cascade models are chosen for investigation. The first two models are based on limited (Binary) and branched (UrQMD) binary scattering between cascade particles which can be either a baryon or meson, in the three-dimensional space of the nucleus, while the latter (FTF) considers collective interactions between nucleons only, on the plane of impact parameter. It is found that the slow (p(T) 0.3 GeV/c) proton spectra are not strongly affected by the differences between the FTF and UrQMD models. It is also shown that the UrQMD and FTF combined with Binary (FTFB) models could reproduce both proton and charged pion spectra from p + Cu and Pb...
Spike Neural Models Part II: Abstract Neural Models
Directory of Open Access Journals (Sweden)
Johnson, Melissa G.
2018-02-01
Full Text Available Neurons are complex cells that require a lot of time and resources to model completely. In spiking neural networks (SNN though, not all that complexity is required. Therefore simple, abstract models are often used. These models save time, use less computer resources, and are easier to understand. This tutorial presents two such models: Izhikevich's model, which is biologically realistic in the resulting spike trains but not in the parameters, and the Leaky Integrate and Fire (LIF model which is not biologically realistic but does quickly and easily integrate input to produce spikes. Izhikevich's model is based on Hodgkin-Huxley's model but simplified such that it uses only two differentiation equations and four parameters to produce various realistic spike patterns. LIF is based on a standard electrical circuit and contains one equation. Either of these two models, or any of the many other models in literature can be used in a SNN. Choosing a neural model is an important task that depends on the goal of the research and the resources available. Once a model is chosen, network decisions such as connectivity, delay, and sparseness, need to be made. Understanding neural models and how they are incorporated into the network is the first step in creating a SNN.
The ATLAS hadronic tau trigger
Black, C; The ATLAS collaboration
2012-01-01
With the high luminosities of proton-proton collisions achieved at the LHC, the strategies for triggering have become more important than ever for physics analysis. The naive inclusive single tau lepton triggers now suffer from severe rate limitations. To allow for a large program of physics analyses with taus, the development of topological triggers that combine tau signatures with other measured quantities in the event is required. These combined triggers open many opportunities to study new physics beyond the Standard Model and to search for the Standard Model Higgs. We present the status and performance of the hadronic tau trigger in ATLAS. We demonstrate that the ATLAS tau trigger ran remarkably well over 2011, and how the lessons learned from 2011 led to numerous improvements in the preparation of the 2012 run. These improvements include the introduction of tau selection criteria that are robust against varying pileup scenarios, and the implementation of multivariate selection techniques in the tau trig...
The ATLAS hadronic tau trigger
Black, C; The ATLAS collaboration
2012-01-01
With the high luminosities of proton-proton collisions achieved at the LHC, the strategies for triggering have become more important than ever for physics analysis. The naïve inclusive single tau lepton triggers now suffer from severe rate limitations. To allow for a large program of physics analyses with taus, the development of topological triggers that combine tau signatures with other measured quantities in the event is required. These combined triggers open many opportunities to study new physics beyond the Standard Model and to search for the Standard Model Higgs. We present the status and performance of the hadronic tau trigger in ATLAS. We demonstrate that the ATLAS tau trigger ran remarkably well over 2011, and how the lessons learned from 2011 led to numerous improvements in the preparation of the 2012 run. These improvements include the introduction of tau selection criteria that are robust against varying pileup scenarios, and the implementation of multivariate selection techniques in the tau tri...
International Nuclear Information System (INIS)
Synodinos, J.N.
1995-07-01
During the running periods of the years 1992, 1993, 1994 the BES experiment at the Beijing Electron Positron Collider (BEPC) collected 22.9 ± 0.7 pb -1 of data at an energy of 4.03 GeV, which corresponds to a local peak for e + e - → D s + D s - production. Four D s hadronic decay modes were tagged: D s → φπ; φ → K + K - ; D s → bar K*(892) o K; bar K* o (892) → K - π + ; D s bar K o K; bar K s o → π + π - ; D s → bar K*(892) o K*; bar K* o (892) → K - π + ; K*(892) → K o π + ; K s o → π + π - . Using the method of double-tagging, BES performed the first model-independent measurement of BrD s → φπ . Our result was Br D s → φπ = 3.4 -1.7-0.7 +4.8+1.3
Salerno, Daniel Nicholas
2018-01-01
I present my work at the CMS experiment on a search for the standard model (SM)Higgs boson produced in association with top quarks. The search is targeted towards¯ﬁnal states compatible with the H → bb decay and the fully hadronic decay channelof the t¯ pair, and uses data from proton-proton collisions at a centre-of-mass energytof 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1 . This is a challengingsearch with many ﬁnal state particles that cannot be uniquely identiﬁed and with largecontamination from SM background processes. It is performed for the ﬁrst time at CMS√and the ﬁrst time anywhere at s = 13 TeV, and contributes to the overall sensitivityof the t¯H cross section measurement, which constitutes a crucial test of the SM.tThe CMS apparatus is a multipurpose detector operating at the LHC, which is ahadron collider at CERN. The CMS detector operates a 3.8 T superconducting solenoid,and includes dedicated subsystems for charged particle tracking near the interactionpoi...
High intensity hadron facility, AGS II
International Nuclear Information System (INIS)
Lee, Y.Y.; Lowenstein, D.I.
1989-01-01
There is a large and growing community of particle and nuclear physicists around the world who are actively lobbying for the construction of an accelerator that could provide 1-2 orders of magnitude increase in proton intensity above that of the present AGS. There have been a series of proposals from Canada, Europe, Japan, and the USA. They can all be characterized as machines varying in energy from 12-60 GeV and intensities of 30-100 μA. The community of physicists using the AGS are in a unique position however. The AGS is the only machine available that can provide the beams to execute the physics program that this large international community is interested in. The BNL approach to the communities interests involves a stepwise intensity upgrade program. At present the AGS slow extracted beam current is 1 μA. With the completion of the Booster in 1990 and the associated AGS modifications, the current will rise to 4-5 μA. With the subsequent addition of the Stretcher which is under design, the current will rise to 8-10 μA and approximately 100% duty factor. The possibility of a further enhancement to a current level of 40-50 μA CW is now being examined. 2 figures, 6 tables
Intermediate-energy hadron interactions, II
International Nuclear Information System (INIS)
Silbar, R.R.
1988-01-01
The topics to be covered are as follows. I'll begin with new developments in NN → NNπ reactions. This will provide a natural lead-in to the main topic of this talk, which is dibaryons. This will be followed by discussion of elastic proton-deuteron and inelastic proton-alpha scattering. Then there will be a brief mention of two technical developments. Finally, I'll close by giving short remarks about two peculiarities that were found by theorists looking at strong interaction amplitudes. 15 refs., 3 figs
Theoretical models for Type I and Type II supernova
International Nuclear Information System (INIS)
Woosley, S.E.; Weaver, T.A.
1985-01-01
Recent theoretical progress in understanding the origin and nature of Type I and Type II supernovae is discussed. New Type II presupernova models characterized by a variety of iron core masses at the time of collapse are presented and the sensitivity to the reaction rate 12 C(α,γ) 16 O explained. Stars heavier than about 20 M/sub solar/ must explode by a ''delayed'' mechanism not directly related to the hydrodynamical core bounce and a subset is likely to leave black hole remnants. The isotopic nucleosynthesis expected from these massive stellar explosions is in striking agreement with the sun. Type I supernovae result when an accreting white dwarf undergoes a thermonuclear explosion. The critical role of the velocity of the deflagration front in determining the light curve, spectrum, and, especially, isotopic nucleosynthesis in these models is explored. 76 refs., 8 figs
Dibaryonic degrees of freedom in Hadronic and nuclear physics
International Nuclear Information System (INIS)
Kukulin, V.I.; Shikhalev, M.A.
2005-01-01
The basic aim of the talk is to show that the dibaryons (independently upon the fact of existence or nonexistence of narrow dibaryons) may become one of the main ingredients and degrees of freedom in hadronic and nuclear physics. It follows straightforwardly from the new model for nuclear force, in which the intermediate-state dibaryons play the role of main carriers of strong interaction of nucleons at intermediate and short ranges in 2N, 3N and other nuclear systems. These intermediate-state dibaryons, or dressed six-quark bags in NN-scattering are strongly coupled to the initial and final NN-channels and thus they have large widths which prevent their direct experimental evidence. However the new model predicts a lot of new effects of dibaryons, which should be seen experimentally in hadronic and nuclear processes. Some of these new predictions have been already confirmed in numerous calculations made jointly in Moscow and Tuebingen university groups. We enumerate shortly here only the most interesting effects of dibaryons in hadronic and nuclear physics: (i) partial restoration of chiral symmetry in multiquark (i.e. 6q, 9q etc.) systems with the respective reduction of the scalar sigma-meson mass; (ii) enhancement of the near-threshold π 0 and π + π − , π 0 π 0 – production in pp, pd etc. collisions; explanation of the long-term ABC-puzzle; (iii) enhancement of the vector-meson and (e + e − ) production in the GeV region in pp, pd etc. collisions; (iv) large yield of cumulative mesons and other hadrons (studied experimentally by Baldin with coworkers) in p-A, d-A etc. high-energy collisions; (v) new electro-magnetic currents related intimately to the dibaryon degrees of freedom, which contribute to the all deuteron e.-m. observables, like deuteron magnetic and quadrupole moments, cross sections of photo-disintegration etc.; (vi) some novel contribution to the Coulomb energies of all nuclei (∼ 15%), which is able to explain the long-standing Nollen
Anisotropic Bianchi II cosmological models with matter and electromagnetic fields
International Nuclear Information System (INIS)
Soares, D.
1978-01-01
A class of solutions of Einstein-Maxwell equations is presented, which corresponds to anisotropic Bianchi II spatially homogeneous cosmological models with perfect fluid and electromagnetic field. A particular model is examined and shown to be unstable for perturbations of the electromagnetic field strength parameter about a particular value. This value defines a limiar unstable case in which the ratio epsilon, of the fluid density to the e.m. energy density is monotonically increasing with a minimum finite value at the singularity. Beyond this limiar, the model has a matter dominated singularity, and a characteristic stage appears where epsilon has a minimum, at a finite time from the singularity. For large times, the models tend to an exact solution for zero electromagnetic field and fluid with p = (1/5)p. Some cosmological features of the models are calculated, as the effect of anisotropy on matter density and expansion time scale factors, as compared to the corresponding Friedmann model [pt
Quantum chromodynamics and hadron jets
International Nuclear Information System (INIS)
Dokshitser, Y.L.; Dyakonov, D.I.
1979-07-01
These lectures are devoted to the description of the various properties of hard scattering processes with the participation of hadrons in the framework of Quantum Chromodynamics. We discuss in detail the validity and region of applicability of perturbation theory applied to hadron processes. Particular attention is paid to the question of the structure of quark and gluon jets produced in hard processes (as an example, e + e - annihilation into hadrons). In addition to giving a pedagogical review, we also present new results. (orig.)
Hadron collider physics at UCR
International Nuclear Information System (INIS)
Kernan, A.; Shen, B.C.
1997-01-01
This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e + -e - collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2γ at PEP and the OPAL detector at LEP, as well as efforts on hadron machines
An Analysis Plan for the ARCOMS II (Armor Combat Operations Model Support II) Experiment.
1983-06-01
In order to facilitate Armor Combat Modeling, the data analysis shculd focus upon the methods which transform the data intc descriptive or predictive ...discussed in Chapter III tc predict the Farameter for probability of detection in time ŕt. This should be compared with the results of the N.4gh -t Vision...J 6A 46.) I-I 0 f U-CL 0~ z o -Z 06 09 03 v 0 0 SJldnYS 10 ON Ipgr Cp o LSTm n at emn itgas 4AA rI z ;A (AZ - 090.0 UlA0 -O ON 404 Fiur CAd &P CC
Summary: Hadron dynamics sessions
International Nuclear Information System (INIS)
Carroll, A.S.; Londergan, J.T.
1993-01-01
Four sessions on Hadron Dynamics were organized at this Workshop. The first topic, QCD Exclusive Reactions and Color Transparency, featured talks by Ralston, Heppelman and Strikman; the second, QCD and Inclusive Reactions had talks by Garvey, Speth and Kisslinger. The third dynamics session, Medium Modification of Elementary Interactions had contributions from Kopeliovich, Alves and Gyulassy; the fourth session Pre-QCD Dynamics and Scattering, had talks by Harris, Myhrer and Brown. An additional joint Spectroscopy/Dynamics session featured talks by Zumbro, Johnson and McClelland. These contributions are reviewed briefly in this summary. Two additional joint sessions between Dynamics and η physics are reviewed by the organizers of the Eta sessions. In such a brief review there is no way the authors can adequately summarize the details of the physics presented here. As a result, they concentrate only on brief impressionistic sketches of the physics topics discussed and their interrelations. They include no bibliography in this summary, but simply refer to the talks given in more detail in the Workshop proceedings. They focus on topics which were common to several presentations in these sessions. First, nuclear and particle descriptions of phenomena are now clearly converging, in both a qualitative and quantitative sense; they show several examples of this convergence. Second, an important issue in hadron dynamics is the extent to which elementary interactions are modified in nuclei at high energies and/or densities, and they illustrate some of these medium effects. Finally, they focus on those dynamical issues where hadron facilities can make an important, or even a unique, contribution to the knowledge of particle and nuclear physics
Energy Technology Data Exchange (ETDEWEB)
Anon.
1979-04-15
Ever since the discovery of charmed mesons in electron-positron annihilations at SLAC and DESY, a considerable effort has gone into looking for them in other types of reactions. Both neutrino interactions and photoproduction have provided further data on the production and decay of D mesons, but little has emerged concerning purely hadronic studies.some results from a CERN/Collège de France/Heidelberg/Karlsruhe collaboration using the Split Field Magnet at the CERN Intersecting Storage Rings (ISR) now show definite signs of D meson production in proton-proton collisions.
International Nuclear Information System (INIS)
Faccini, R.
2010-01-01
In the past few years the field of hadron spectroscopy has seen renewed interest due to the publication, initially mostly from B-Factories, of evidences of states that do not match regular spectroscopy, but are rather candidates for bound states with additional quarks or gluons (four quarks for tetraquarks and molecules and two quarks and gluons for hybrids). A huge effort in understanding the nature of this new states and in building a new spectroscopy is ongoing. This paper reviews the experimental and theoretical state of the art on heavy quarkonium exotic spectroscopy, with particular attention on the steps towards a global picture.
International Nuclear Information System (INIS)
Dremin, I.M.
1981-01-01
The process of the coherent production of hadrons analogous to Cherenkov radiation of photons is considered. Its appearence and qualitative treatment are possible now because it is known from experiment that the real part of the πp (and pp) forward elastic scattering amplitude is positive at high energies. The threshold behaviour of the process as well as very typical angular and psub(T)-distributions where psub(t)-transverse momentum corresponding to the ring structure of the target diagram at rather large angles and to high-psub(T) jet production are emphasized [ru
Directory of Open Access Journals (Sweden)
Wada Masayuki
2012-11-01
Full Text Available The results of resonance particle productions (ρ0, ω, K*, ϕ, Σ*, and Λ* measured by the STAR collaboration at RHIC from various colliding systems and energies are presented. Measured mass, width, 〈pT〉, and yield of those resonances are reviewed. No significant mass shifts or width broadening beyond the experiment uncertainties are observed. New measurements of ϕ and ω from leptonic decay channels are presented. The yields from leptonic decay channels are compared with the measurements from hadronic decay channels and the two results are consistent with each other.
Hadronic processes and electromagnetic corrections
International Nuclear Information System (INIS)
Scimemi, I.
2004-01-01
The inclusion of electromagnetism in a low energy effective theory is worth further study in view of the present high precision experiments (muon g - 2, π 0 → γγ, τ decays, etc.). In particular in many applications of chiral perturbation theory, one has to purify physical matrix elements from electromagnetic effects. The theoretical problems that I want to point out here are following: the splitting of a pure QCD and a pure electromagnetic part in a hadronic process is model dependent: is it possible to parametrise in a clear way this splitting? What kind of information (scale dependence, gauge dependence,) is actually included in the parameters of the low energy effective theory? I will attempt to answer these questions introducing a possible convention to perform the splitting between strong and electromagnetic parts in some examples
Quarks for hadrons and leptons
International Nuclear Information System (INIS)
Lopes, J.L.
1975-01-01
The simplest, naive, model for a unified description of leptons and hadrons consists in postulating, besides the usual quarks p, n, lambda a fourth quark, with very heavy mass and very high binding to pairs like anti p n and anti p lambda. In a SU(4) scheme the fourth quark has a quantum number charm which may be taken as proportional to the lepton number. Muons would be distinguished from electrons by the occurence of a lambda-quark instead of a n-quark in their structure. The forces among these quarks would have to be such as to give leptons an almost point-like structure at the experimentally known energies as well as absence of strong interactions at these energies. However, one would expect the display of strong interactions by leptons at extremely high energies [pt
Ozvenchuk, V.; Rybicki, A.
2018-05-01
The UrQMD transport model, version 3.4, is used to study the new experimental data on transverse momentum spectra of π±, K±, p and p bar produced in inelastic p + p interactions at SPS energies, recently published by the NA61/SHINE Collaboration. The comparison of model predictions to these new measurements is presented as a function of collision energy for central and forward particle rapidity intervals. In addition, the inverse slope parameters characterizing the transverse momentum distributions are extracted from the predicted spectra and compared to the corresponding values obtained from NA61/SHINE distributions, as a function of particle rapidity and collision energy. A complex pattern of deviations between the experimental data and the UrQMD model emerges. For charged pions, the fair agreement visible at top SPS energies deteriorates with the decreasing energy. For charged K mesons, UrQMD significantly underpredicts positive kaon production at lower beam momenta. It also underpredicts the central rapidity proton yield at top collision energy and overpredicts antiproton production at all considered energies. We conclude that the new experimental data analyzed in this paper still constitute a challenge for the present version of the model.
International Nuclear Information System (INIS)
Cahill, R.T.
1992-01-01
A review is given of progress in deriving the effective action for hadronic physics, S[π, ρ, ω, .., anti N, N, ..], from the fundamental defining action of QCD, S[anti q, q, A μ a ]. This is a problem in quantum field theory and the most success so far has been achieved using functional integral calculus (FIC) techniques. This formulates the problem as an exercise in changing the variables of integration in the functional integrals, from those of the quark and gluon fields to those of the (bare) meson and baryon fields. The appropriate variables are determined by the dynamics of QCD, and the final hadronic variables (essentially the 'normal modes' of QCD) are local fields describing the 'centre-of-mass' motion of extended bound states of quarks. The quarks are extensively dressed by the gluons, and the detailed aspects of the hidden chiral symmetry emerge naturally from the formalism. Particular attention is given to covariant integral equations which determine bare nucleon structure (i.e. in the quenched approximation). These equations, which arise from the closed double-helix diagrams of the FIC analysis, describe the baryons in terms of quark-diquark structure, in the form of Faddeev equations. This hadronisation of QCD also generates the dressing of these baryons by the pions, and the non-local πNN coupling. (orig.)
International Nuclear Information System (INIS)
Dzhelyadin, R.I.
2002-01-01
The Hadron Calorimeter (HCAL) is designed for the LHCb experiment. The main purpose of the detector is to provide data for the L0 hadron trigger. The HCAL is designed as consisting of two symmetric movable parts of about 500 ton in total getting in touch in operation position without non-instrumented zones. The lateral dimensions of an active area are X=8.4 m width, Y=6.8 m height, and is distanced from the interaction point at Z=13.33 m. Both halves are assembled from stacked up modules. An internal structure consisting of thin iron plates interspaced with scintillating tiles has been chosen. Attention is paid to optimize the detector according to the requirements of the experiment, reducing the spending needed for its construction. Different construction technologies are being discussed. The calorimeter properties have been extensively studied with a variety of prototype on the accelerator beam. The calibration with a radioactive source and module-0 construction experience is discussed
Charmed hadron production in pp collision
Goswami, Umananda Dev
2007-10-01
We investigated the production of charmed hadrons ( D+, D-, D0, D, Λc+, Λ¯c-) in pp collisions as a function of √{s}, xF, p⊥2 and p⊥ in the framework of the QGSJET model. The study of charmed hadron production characteristics in pp collision is particularly important for cosmic ray physics in the context of atmospheric prompt lepton fluxes. Here our aim is to check the reliability of the QGSJET model to be used to study the production of charmed hadrons in cosmic ray hadronic interactions with air nuclei. Charmed hadroproduction cross sections or the charmed hadron average multiplicities in pp collisions are relatively very small. The maximum production of all charmed hadrons takes place with low values of xF, p⊥2, and p⊥ within a small range for all values of √{s} under study. Charmed hadroproduction cross sections as a function of xF and p⊥2 are compared with the LEBC-EHS and LEBC-MPS experiment data for D-meson production. The agreement is quite satisfactory for smaller values of p⊥2 (⩽2 (GeV/c) 2). There is an asymmetry in charmed hadroproduction in pp collision. For all xF, asymmetry is prominent in the low value of √{s}. There is a strong preference for producing Λc+ rather than Λ¯c-baryons, while that for producing D¯ rather than D-mesons for this range of √{s}. Asymmetry increases from zero to ±1 around xF = 0.3 for all values of √{s} and for all charmed hardron groups. The patterns of asymmetric production of different charmed hadrons with xF are approximately the same as that with √{s}. We compare our calculation with the data from Fermilab experiment E781 (SELEX) for Λc-baryon production. The agreement is quite good. The asymmetry of charmed hadroproduction with p⊥ does not follow any well defined pattern.
International Nuclear Information System (INIS)
Hanson, G.; Alam, M.S.; Boyarski, A.M.; Breidenbach, M.; Bulos, F.; Dakin, J.T.; Dorfan, J.M.; Feldman, G.J.; Fischer, G.E.; Fryberger, D.; Hartill, D.L.; Jaros, J.A.; Jean-Marie, B.; Larsen, R.R.; Lueth, V.; Lynch, H.L.; Lyon, D.; Morehouse, C.C.; Paterson, J.M.; Perl, M.L.; Peruzzi, I.; Piccolo, M.; Pun, T.P.; Rapidis, P.; Richter, B.; Schindler, R.H.; Schwitters, R.F.; Siegrist, J.L.; Tanenbaum, W.; Vannucci, F.; Abrams, G.S.; Briggs, D.; Carithers, W.C.; Chinowsky, W.; Cooper, S.; DeVoe, R.G.; Friedberg, C.E.; Goldhaber, G.; Hollebeek, R.J.; Johnson, A.D.; Kadyk, J.A.; Litke, A.M.; Madaras, R.J.; Nguyen, H.K.; Pierre, F.M.; Sadoulet, B.; Trilling, G.H.; Whitaker, J.S.; Winkelmann, F.C.; Wiss, J.E.
1982-01-01
We present results on the jet structure observed in multihadronic events produced by e + e - annihilation in the Mark I magnetic detector at SPEAR. The evidence for jet structure and the jet-axis angular distribution are reported. We give inclusive distributions of the hadrons in Feynman x, rapidity, and transverse momentum relative to the jet axis
International Nuclear Information System (INIS)
Grab, Sebastian
2009-08-01
The most widely studied supersymmetric scenario is the minimal supersymmetric standard model (MSSM) with more than a hundred free parameters. However for detailed phenomenological studies, the minimal supergravity (mSUGRA) model, a restricted and well-motivated framework for the MSSM, is more convenient. In this model, lepton- and baryon-number violating interactions are suppressed by a discrete symmetry, R-parity or proton-hexality, to keep the proton stable. However, it is sufficient to forbid only lepton- or baryon-number violation. We thus extend mSUGRA models by adding a proton-hexality violating operator at the grand unification scale. This can change the supersymmetric spectrum leading on the one hand to a sneutrino, smuon or squark as the lightest supersymmetric particle (LSP). On the other hand, a wide parameter region is reopened, where the scalar tau (stau) is the LSP. We investigate in detail the conditions leading to non-neutralino LSP scenarios. We take into account the restrictions from neutrino masses, the muon anomalous magnetic moment, b→sγ, and other precision measurements. We furthermore investigate existing restrictions from direct searches at LEP, the Tevatron, and the CERN p anti p collider. It is vital to know the nature of the LSP, since supersymmetric particles normally cascade decay down to the LSP at collider experiments. We present typical LHC signatures for sneutrino LSP scenarios. Promising signatures are high-p T muons and jets, like-sign muon events and detached vertices from long lived taus. We also classify the stau LSP decays and describe their dependence on the mSUGRA parameters. We then exploit our results for resonant single slepton production at the LHC. We find novel signatures with like-sign muon and three- and four-muon final states. Finally, we perform a detailed analysis for single slepton production in association with a single top quark. We show that the signal can be distinguished from the background at the LHC
Quarkonium production in hadronic collisions
International Nuclear Information System (INIS)
Gavai, R.; Schuler, G.A.; Sridhar, K.
1995-01-01
We summarize the theoretical description of charmonium and bottonium production in hadronic collisions and compare it to the available data from hadron-nucleon interactions. With the parameters of the theory established by these data, we obtain predictions for quarkonium production at RHIC and LHC energies
Hadron induced leptons and photons
International Nuclear Information System (INIS)
Cronin, J.W.
1977-01-01
A review of direct production of leptons and photons in hadron-hadron collisions is presented. Production of lepton pairs with large mass is well accounted for by the Drell-Yan process. The origin of direct single leptons is principally due to the production of lepton pairs. A dominant source of lepton pairs is at low effective mass, m [de
Spin structure of hadronization products
International Nuclear Information System (INIS)
Clavelli, L.
1979-03-01
We point out that the hypothesis of soft hadronization together with Lorentz invariance strongly constrain the hadronization process ine + e - annihilation. A final stage jet hypothesis is made which satisfies these constraints. The resulting picture leads to testable predictions not obtainable from perturbative QCD. (orig.) [de
Hadrons in dense matter. Proceedings
International Nuclear Information System (INIS)
Buballa, M.; Noerenberg, W.; Schaefer, B.J.; Wambach, J.
2000-03-01
The following topics were dealt with: Elementary hadronic reactions, Delta dynamics in nuclei, in-medium s-wave ππ-correlations, strangeness in hot and dense matter, medium modifications of vector mesons and dilepton production, medium modifications of charmonium, thermal properties of hot and dense hadronic matter, nuclear matter, spectral functions and QCD sum rules
Karaca, Koray
2017-01-01
According to the hierarchy of models (HoM) account of scientific experimentation developed by Patrick Suppes and elaborated by Deborah Mayo, theoretical considerations about the phenomena of interest are involved in an experiment through theoretical models that in turn relate to experimental data
Fedynitch, Anatoli; Tjus, Julia Becker; Desiati, Paolo
2012-01-01
The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to...
Energy Technology Data Exchange (ETDEWEB)
Grab, Sebastian
2009-08-15
The most widely studied supersymmetric scenario is the minimal supersymmetric standard model (MSSM) with more than a hundred free parameters. However for detailed phenomenological studies, the minimal supergravity (mSUGRA) model, a restricted and well-motivated framework for the MSSM, is more convenient. In this model, lepton- and baryon-number violating interactions are suppressed by a discrete symmetry, R-parity or proton-hexality, to keep the proton stable. However, it is sufficient to forbid only lepton- or baryon-number violation. We thus extend mSUGRA models by adding a proton-hexality violating operator at the grand unification scale. This can change the supersymmetric spectrum leading on the one hand to a sneutrino, smuon or squark as the lightest supersymmetric particle (LSP). On the other hand, a wide parameter region is reopened, where the scalar tau (stau) is the LSP. We investigate in detail the conditions leading to non-neutralino LSP scenarios. We take into account the restrictions from neutrino masses, the muon anomalous magnetic moment, b{yields}s{gamma}, and other precision measurements. We furthermore investigate existing restrictions from direct searches at LEP, the Tevatron, and the CERN p anti p collider. It is vital to know the nature of the LSP, since supersymmetric particles normally cascade decay down to the LSP at collider experiments. We present typical LHC signatures for sneutrino LSP scenarios. Promising signatures are high-p{sub T} muons and jets, like-sign muon events and detached vertices from long lived taus. We also classify the stau LSP decays and describe their dependence on the mSUGRA parameters. We then exploit our results for resonant single slepton production at the LHC. We find novel signatures with like-sign muon and three- and four-muon final states. Finally, we perform a detailed analysis for single slepton production in association with a single top quark. We show that the signal can be distinguished from the background
Signatures of chromodynamics in hadron collisions
International Nuclear Information System (INIS)
Halzen, F.
1979-01-01
The quantum chromodynamics (QCD) describes the interaction of the parton constituents of hadrons (quarks and gluons) via eight colored photons (gluons) interacting with the quarks, and unlike the photons, with each other. The simple picture of Drell-Yan model has made surprising success. The marriage of the old fashion Drell-Yan parton model with QCD has not only made its phenomenological success in the study of lepton pair production, but has allowed to study quantitatively the gluon correction to the model. Information from beam dump and emulsion experiments on charm production is compared with the typical QCD diagram. The results indicate some possible non-perturbative contribution to the photon- and hadron-production of heavy quarks. The definite features of dilepton as well as large transverse momentum data are direct signature of gluons. (Kato, T.)
Inclusive hadron production at high momentum at SPEAR I
International Nuclear Information System (INIS)
Goggi, G.
Recent results of the Maryland-Pavia-Princeton collaboration on inclusive hadron production in e + e - annihilation at √s=4.8GeV are presented. The results are discussed in the framework of other results obtained at SPEAR I and of the implications at the higher energies attainable at SPEAR II
Radiative transitions from the psi (3095) to ordinary hadrons
Energy Technology Data Exchange (ETDEWEB)
Scharre, D.L.
1980-05-01
Preliminary results from the Mark II and Crystal Ball experiments on radiative transitions from the psi to ordinary hadrons are presented. In additon to the previously observed transitions to the eta, eta'(958), and f(1270), both groups observe a transition to a state which is tentatively identified as the E(1420).
arXiv CP violation in $b$ hadrons at LHCb
INSPIRE-00028041
The most recent results on CP violation in $b$ hadrons obtained by the LHCb Collaboration with Run I and years 2015-2016 of Run II are reviewed. The different types of violation are covered by the studies presented in this paper.
Prospects for heavy flavor physics at hadron colliders
International Nuclear Information System (INIS)
Butler, J.N.
1997-09-01
The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the B s meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with 'forward' vs 'central' rapidity coverage
Hadron production by virtual photons in the quark fragmentation region
International Nuclear Information System (INIS)
Scarr, J.M.; Chen, C.K.; Knowles, J.; Martin, D.; Skillicorn, I.O.; Smith, K.; Joos, P.; Ladage, A.; Meyer, H.; Wolf, G.
1977-11-01
We have measured the inclusive electroproduction of positive and negative hadrons in the quark fragmentation region using the streamer chamber at DESY. Data are presented in terms of the variable zsub(p) = p/ν in the kinematic region 1.8 2 2 . The positive hadron distributions contain a strong proton component. After subtraction of the proton component and elastic rho events, the distribution 1/sigma sub(tot) (dsigma/dz sub(p)) for positive and negative hadrons agrees well with the corresponding distribution from e + e - annihilation (DORIS data). This behaviour supports the validity of the quark parton model at surprisingly low Q 2 and W. (orig.) [de
Kinetic modelling for zinc (II) ions biosorption onto Luffa cylindrica
International Nuclear Information System (INIS)
Oboh, I.; Aluyor, E.; Audu, T.
2015-01-01
The biosorption of Zinc (II) ions onto a biomaterial - Luffa cylindrica has been studied. This biomaterial was characterized by elemental analysis, surface area, pore size distribution, scanning electron microscopy, and the biomaterial before and after sorption, was characterized by Fourier Transform Infra Red (FTIR) spectrometer. The kinetic nonlinear models fitted were Pseudo-first order, Pseudo-second order and Intra-particle diffusion. A comparison of non-linear regression method in selecting the kinetic model was made. Four error functions, namely coefficient of determination (R 2 ), hybrid fractional error function (HYBRID), average relative error (ARE), and sum of the errors squared (ERRSQ), were used to predict the parameters of the kinetic models. The strength of this study is that a biomaterial with wide distribution particularly in the tropical world and which occurs as waste material could be put into effective utilization as a biosorbent to address a crucial environmental problem
Are Hadrons and Nuclei Open Systems ?
International Nuclear Information System (INIS)
Musulmanbekov, G.
1998-01-01
Fulltext We propose to consider the structure of hadrons in the frame of stochastic interpretation of quantum mechanics, or stochastic theory, which is based on classical mechanics in stochastic environment. This environment is associated with subquantal vacuum. Stochastic theory is a classical physics without the hypothesis that there are isolated systems in the universe. It has been shown by some authors that stochastic theory is justified by fractal space-time considerations. In our approach hadron is a set of embedded into stochastic vacuum (SV) valence quarks (VQ) ( quark-antiquark in mesons and three quarks in baryons ) oscillating near center of proper frame of the hadron VQ being placed into SV behaves itself as a dislocation (antidislocation) in solids or vortex ( antivortex ) in liquids. Effective interaction between VQs comes from specific polarization of SV around VQs leading to outside suppression on VQs. Polarization of SV around VQ characterizes the distribution of hardonic matter inside a hadron. Oscillation motion of VQs around the origin, going from their interaction with SV, is strongly correlated. VQs being in equilibrium with SV exchange energy at all times with it. Neighborhood of two or more nucleons changes SV polarization around their VQs in such a way that they tend to occupy the state with minimum energy arrange crystalline like structure. Therefore the behavior of hadrons and nuclei is typical for open systems exchanging energy with environment .In this approach the relation between constituent (nonrelativistic ) quarks and current ( relativistic) ones becomes clear and transparent, because it composes the features of both NRQM and bag models. It gives qualitative and in some cases quantitative description of experimental facts concerning nucleon and nuclear structure searched in scattering experiments. Some proposals and predictions for future experiments are given
HIGH ENERGY HADRON POLARIMETRY
International Nuclear Information System (INIS)
BUNCE, G.
2007-01-01
Proton polarimetry at RHIC uses the interference of electromagnetic (EM) and hadronic scattering amplitudes. The EM spin-flip amplitude for protons is responsible for the proton's anomalous magnetic moment, and is large. This then generates a significant analyzing power for small angle elastic scattering. RHIC polarimetry has reached a 5% uncertainty on the beam polarization, and seem capable of reducing this uncertainty further. Polarized neutron beams ax also interesting for RHIC and for a polarized electron-polarized proton/ion collider in the fume. In this case, deuterons, for example, have a very small anomalous magnetic moment, making the approach used for protons impractical. Although it might be possible to use quasielastic scattering from the protons in the deuteron to monitor the polarization. 3-He beams can provide polarized neutrons, and do have a large anomalous magnetic moment, making a similar approach to proton polarimetry possible
CMS hadronic forward calorimeter
International Nuclear Information System (INIS)
Merlo, J.P.
1998-01-01
Tests of quartz fiber prototypes, based on the detection of Cherenkov light from showering particles, demonstrate a detector possessing all of the desirable characteristics for a forward calorimeter. A prototype for the CMS experiment consists of 0.3 mm diameter fibers embedded in a copper matrix. The response to high energy (10-375 GeV) electrons, pions, protons and muons, the light yield, energy and position resolutions, and signal uniformity and linearity, are discussed. The signal generation mechanism gives this type of detector unique properties, especially for the detection of hadronic showers: Narrow, shallow shower profiles, hermeticity and extremely fast signals. The implications for measurements in the high-rate, high-radiation LHC environment are discussed. (orig.)
International Nuclear Information System (INIS)
Eyraud, L; Furget, C.; Goy, J.; Kox, S.; Merchez, F.; Pastor, A.; Real, J.S.; Russew, T.; Tieulent, R.; Voutier, E.
1997-01-01
Over these two years, our group has been worked in hadronic physics at Saturn and CEBAF using the polarimeter POLDER. Tensor polarization observables have been measured in the reaction H(p bar, d bar)π + between 580 and 1300 MeV proton energy. The group has also been leader in an experiment, performed in 1997 at CEBAF. By measuring the t 20 polarization of the recoil deuteron produced in the elastic electron-deuteron scattering at large Q 2 , the separation of the charge and quadrupole form-factors of the deuteron will be performed for Q=4.1-6.8 fm -1 . Finally, we were involved in the construction and test of the neutron polarimeter HARP and in the definition of the physics program of the ELFE project. (authors)
An estimate of the bulk viscosity of the hadronic medium
Sarwar, Golam; Chatterjee, Sandeep; Alam, Jane
2017-05-01
The bulk viscosity (ζ) of the hadronic medium has been estimated within the ambit of the Hadron Resonance Gas (HRG) model including the Hagedorn density of states. The HRG thermodynamics within a grand canonical ensemble provides the mean hadron number as well as its fluctuation. The fluctuation in the chemical composition of the hadronic medium in the grand canonical ensemble can result in non-zero divergence of the hadronic fluid flow velocity, allowing us to estimate the ζ of the hadronic matter up to a relaxation time. We study the influence of the hadronic spectrum on ζ and find its correlation with the conformal symmetry breaking measure, ε -3P. We estimate ζ along the contours with constant, S/{N}B (total entropy/net baryon number) in the T-μ plane (temperature-baryonic chemical potential) for S/{N}B=30,45 and 300. We also assess the value of ζ on the chemical freeze-out curve for various centers of mass energy (\\sqrt{{s}{NN}}) and find that the bulk viscosity to entropy density ratio, \\zeta /s is larger in the energy range of the beam energy scan program of RHIC, low energy SPS run, AGS, NICA and FAIR, than LHC energies.
Naboka, V. Yu.; Sinyukov, Yu. M.; Zinovjev, G. M.
2018-05-01
The photon transverse momentum spectrum and its anisotropy from Pb+Pb collisions at the CERN Large Hadron Collider energy √{sN N}=2.76 TeV are investigated within the integrated hydrokinetic model (iHKM). Photon production is accumulated from the different processes at the various stages of relativistic heavy ion collisions: from the primary hard photons of very early stage of parton collisions to the thermal photons from equilibrated quark-gluon and hadron gas stages. Along the way a hadronic medium evolution is treated in two distinct, in a sense opposite, approaches: chemically equilibrated and chemically frozen system expansion. Studying the centrality dependence of the results obtained allows us to conclude that a relatively strong transverse momentum anisotropy of thermal radiation is suppressed by prompt photon emission which is an isotropic. We find out that this effect is getting stronger as centrality increases because of the simultaneous increase in the relative contribution of prompt photons in the soft part of the spectra. The substantial results obtained in iHKM with nonzero viscosity (η /s =0.08 ) for photon spectra and v2 coefficients are mostly within the error bars of experimental data, but there is some systematic underestimation of both observables for the near central events. We claim that a situation could be significantly improved if an additional photon radiation that accompanies the presence of a deconfined environment is included. Since a matter of a space-time layer where hadronization takes place is actively involved in anisotropic transverse flow, both positive contributions to the spectra and v2 are considerable, albeit such an argument needs further research and elaboration.
Hadronic collision and hadronic structure (an experimental review)
International Nuclear Information System (INIS)
Davier, M.
1975-01-01
In this set of lectures an attempt is made to present a survey of the available experimental data on hadronic collisions at large transverse momentum, together with their current phenomenological descriptions. In particular, the experimental confirmation of constituent structure is looked at in a critical way. The emphasis throughout is to let the data speak in the most unbiased way and to gather evidence as to the short range structure of the hadronic interactions. Finally the current information on lepton production in hadronic collisions is reviewed
Galindo-Garre, Francisca; Hidalgo, María Dolores; Guilera, Georgina; Pino, Oscar; Rojo, J Emilio; Gómez-Benito, Juana
2015-03-01
The World Health Organization Disability Assessment Schedule II (WHO-DAS II) is a multidimensional instrument developed for measuring disability. It comprises six domains (getting around, self-care, getting along with others, life activities and participation in society). The main purpose of this paper is the evaluation of the psychometric properties for each domain of the WHO-DAS II with parametric and non-parametric Item Response Theory (IRT) models. A secondary objective is to assess whether the WHO-DAS II items within each domain form a hierarchy of invariantly ordered severity indicators of disability. A sample of 352 patients with a schizophrenia spectrum disorder is used in this study. The 36 items WHO-DAS II was administered during the consultation. Partial Credit and Mokken scale models are used to study the psychometric properties of the questionnaire. The psychometric properties of the WHO-DAS II scale are satisfactory for all the domains. However, we identify a few items that do not discriminate satisfactorily between different levels of disability and cannot be invariantly ordered in the scale. In conclusion the WHO-DAS II can be used to assess overall disability in patients with schizophrenia, but some domains are too general to assess functionality in these patients because they contain items that are not applicable to this pathology. Copyright © 2014 John Wiley & Sons, Ltd.
High energy hadron-nucleus collision
International Nuclear Information System (INIS)
Takagi, Fujio
1983-02-01
This is a lecture note concerning high energy hadron-nucleus collision. The lecture gives the inelastic total cross section and the Glanber approximate multiple scattering formula at first. The mechanism of nuclear spallation is described in a cylindrical image. The multiplicity, the one particle distribution and the time-space structure of particle production are discussed. Various models are presented. The attenuation of forward particles and the structure of hadrons are discussed for each model. The atomic number (A) dependence of the production of large transverse momentum particles and jet, and the A dependence of charged multiplicity are presented. The backward production of particles and many body correlation are discussed. Lepton pair production and the initial interaction of constituents, collective interaction, multi quark state and phase transition are described. (Kato, T.)
Transverse Momentum Correlations in Hadronic Z decays
Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; 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; Alemany, R; Bazarko, A O; Bonvicini, G; Bright-Thomas, P G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rizzo, G; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Bauer, C; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Schune, M H; Simion, S; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; 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; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G
1997-01-01
Using data obtained with the ALEPH detector at the Z resonance, a measure based on transverse momentum is shown to exhibit a correlation between the two halves of a hadronic event which cannot be explained by energy-momentum conservation, flavour conservation, the imposition of an event axis or imperfect event reconstruction. Two possible explanations based on Monte Carlo models are examined: a) ARIADNE, with the correlation forming early in the parton shower and with the transition from partons to hadrons playing only a minor part; b) JETSET, with the correlation forming at the fragmentation stage. A correlation technique based on a jet cluster analysis is used to make a comparison of the models with the data. It is concluded that both non-perturbative and perturbative effects make important contributions to the observed correlation.
Hadronic production of massive lepton pairs
International Nuclear Information System (INIS)
Berger, E.L.
1982-12-01
A review is presented of recent experimental and theoretical progress in studies of the production of massive lepton pairs in hadronic collisions. I begin with the classical Drell-Yan annihilation model and its predictions. Subsequently, I discuss deviations from scaling, the status of the proofs of factorization in the parton model, higher-order terms in the perturbative QCD expansion, the discrepancy between measured and predicted yields (K factor), high-twist terms, soft gluon effects, transverse-momentum distributions, implications for weak vector boson (W +- and Z 0 ) yields and production properties, nuclear A dependence effects, correlations of the lepton pair with hadrons in the final state, and angular distributions in the lepton-pair rest frame
Probing leptophilic dark sectors with hadronic processes
D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo
2017-08-01
We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton-antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the Z boson, severely bounded by ElectroWeak Precision Tests. We use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.
Hadron spectroscopy and form factors at quark level
International Nuclear Information System (INIS)
Chakrabarty, S.; Gupta, K.K.; Singh, N.N.; Mitra, A.N.
1988-01-01
The theoretical status of hadrons as quark composites is examined from the point of view of a simultaneous understanding of their on-shell (mass spectra) and off-shell (form factors, transition amplitudes) properties. Greater stress is laid on light quark systems which are more sensitive to the confinement regime, and more prone to relativistic effects than on heavy quarkonia (on which many reviews exist). Two broad theoretical approaches obeying Lorentz and gauge invariance are identified: (i) QCD sum rules as a means of extrapolation from high to low energies; and (ii) dynamical equations for providing a microcausal link in the opposite direction (from low to high energies). The latter represents the major focus of attention in this article, with the Bethe-Salpeter Equation (BSE) providing a formal plank for a comparative assessment of several models. The Null-plane ansatz which facilitates the reduction of the 4-D BSE to a covariant 3-D form also provides the language for its comparison with other covariant 3-D equations. In particular, attention is drawn to the interesting possibility of reconstructing the 4-D BS wave function from its 3-D form (in a two-tier fashion) as a practical tool for generating higher Fock-space components (qq effects) in the BS wave function, and (more interestingly) for a clean separation between soft and hard QCD effects. To illustrate one such practical tool for an integrated view of different hadronic sectors within a single framework, the results of a two-tier BS model are presented in respect of qq-bar, qqq, gg, ggg, gqq-bar states and compared with experiment as well as with the results of other contemporary models. The N.R Resonating Group Method, which becomes necessary for bigger (six-quark) systems is briefly discussed from the point of view of its compatibility with a relativistic form of quark dynamics motivated from the BSC. (Author)
Non-perturbative inputs for gluon distributions in the hadrons
Energy Technology Data Exchange (ETDEWEB)
Ermolaev, B.I. [Ioffe Physico-Technical Institute, Saint Petersburg (Russian Federation); Troyan, S.I. [St. Petersburg Institute of Nuclear Physics, Gatchina (Russian Federation)
2017-03-15
Description of hadronic reactions at high energies is conventionally done in the framework of QCD factorization. All factorization convolutions comprise non-perturbative inputs mimicking non-perturbative contributions and perturbative evolution of those inputs. We construct inputs for the gluon-hadron scattering amplitudes in the forward kinematics and, using the optical theorem, convert them into inputs for gluon distributions in the hadrons, embracing the cases of polarized and unpolarized hadrons. In the first place, we formulate mathematical criteria which any model for the inputs should obey and then suggest a model satisfying those criteria. This model is based on a simple reasoning: after emitting an active parton off the hadron, the remaining set of spectators becomes unstable and therefore it can be described through factors of the resonance type, so we call it the resonance model. We use it to obtain non-perturbative inputs for gluon distributions in unpolarized and polarized hadrons for all available types of QCD factorization: basic, K{sub T}-and collinear factorizations. (orig.)
Non-perturbative inputs for gluon distributions in the hadrons
International Nuclear Information System (INIS)
Ermolaev, B.I.; Troyan, S.I.
2017-01-01
Description of hadronic reactions at high energies is conventionally done in the framework of QCD factorization. All factorization convolutions comprise non-perturbative inputs mimicking non-perturbative contributions and perturbative evolution of those inputs. We construct inputs for the gluon-hadron scattering amplitudes in the forward kinematics and, using the optical theorem, convert them into inputs for gluon distributions in the hadrons, embracing the cases of polarized and unpolarized hadrons. In the first place, we formulate mathematical criteria which any model for the inputs should obey and then suggest a model satisfying those criteria. This model is based on a simple reasoning: after emitting an active parton off the hadron, the remaining set of spectators becomes unstable and therefore it can be described through factors of the resonance type, so we call it the resonance model. We use it to obtain non-perturbative inputs for gluon distributions in unpolarized and polarized hadrons for all available types of QCD factorization: basic, K_T-and collinear factorizations. (orig.)
Observation of exclusive electron-positron production in hadron-hadron collisions.
Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Caron, B; Carosi, R; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; Daronco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; Cecco, S De; Deisher, A; Lentdecker, G De; Dell'orso, M; Paoli, F Delli; Demortier, L; Deng, J; Deninno, M; Pedis, D De; Derwent, P F; Giovanni, G P Di; Dionisi, C; Ruzza, B Di; Dittmann, J R; Dituro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pinfold, J; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Denis, R St; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S
2007-03-16
We present the first observation of exclusive e(+)e(-) production in hadron-hadron collisions, using pp[over] collision data at (square root) s = 1.96 TeV taken by the run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb(-1). We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy E(T) > 5 GeV and pseudorapidity |eta| p + e(+)e(-) + p[over] through two-photon exchange. The measured cross section is 1.6(-0.3)(+0.5)(stat) +/- 0.3(syst) pb. This agrees with the theoretical prediction of 1.71+/-0.01 pb.
Modelling of the PROTO-II crossover network
International Nuclear Information System (INIS)
Proulx, G.A.; Lackner, H.; Spence, P.; Wright, T.P.
1985-01-01
In order to drive a double ring, symmetrically fed bremsstrahlung diode, the PROTO II accelerator was redesigned. The radially converging triplate water line was reconfigured to drive two radial converging triplate lines in parallel. The four output lines were connected to the two input lines via an electrically enclosed tubular crossover network. Low-voltage Time Domain Reflectrometry (TDR) experiments were conducted on a full scale water immersed model of one section of the crossover network as an aid in this design. A lumped element analysis of the power flow through the network was inadequate in explaining the observed wave transmission and reflection characteristics. A more detailed analysis was performed with a circuit code in which we considered both localized lump-element and transmission line features of the crossover network. Experimental results of the model tests are given and compared with the circuit simulations. 7 figs
Exclusive hadron production in two photon reactions
International Nuclear Information System (INIS)
Poppe, M.
1986-02-01
This paper summarises experimental results on exclusive hadron production in two photon collisions at electron positron storage rings and attempts some interpretation. Experimental know how is described and new suggestions are made for future analyses. New model calculations on resonance form factors and pair production amplitudes are presented. The two photon vertex is decomposed such that experiments can be parameterised with the minimal number of free parameters. Selection rules for off shell photon collisions are given in addition to Yang's theorems. (orig.)
Excited quark production at hadron colliders
International Nuclear Information System (INIS)
Baur, U.; Hinchliffe, I.; Zeppenfeld, D.
1987-06-01
Composite models generally predict the existence of excited quark and lepton states. We consider the production and experimental signatures of excited quarks Q* of spin and isospin 1/2 at hadron colliders and estimate the background for those channels which are most promising for Q* identification. Multi-TeV pp-colliders will give access to such particles with masses up to several TeV
System modeling of spent fuel transfers at EBR-II
International Nuclear Information System (INIS)
Imel, G.R.; Houshyar, A.
1994-01-01
The unloading of spent fuel from the Experimental Breeder Reactor-II (EBR-II) for interim storage and subsequent processing in the Fuel Cycle Facility (FCF) is a multi-stage process, involving complex operations at a minimum of four different facilities at the Argonne National Laboratory-West (ANL-W) site. Each stage typically has complicated handling and/or cooling equipment that must be periodically maintained, leading to both planned and unplanned downtime. A program was initiated in October, 1993 to replace the 330 depleted uranium blanket subassemblies (S/As) with stainless steel reflectors. Routine operation of the reactor for fuels performance and materials testing occurred simultaneously in FY 1994 with the blanket unloading. In the summer of 1994, Congress dictated the October 1, 1994 shutdown of EBR-2. Consequently, all blanket S/As and fueled drivers will be removed from the reactor tank and replaced with stainless steel assemblies (which are needed to maintain a precise configuration within the grid so that the under sodium fuel handling equipment can function). A system modeling effort was conducted to determine the means to achieve the objective for the blanket and fuel unloading program, which under the current plan requires complete unloading of the primary tank of all fueled assemblies in 2 1/2 years. A simulation model of the fuel handling system at ANL-W was developed and used to analyze different unloading scenarios; the model has provided valuable information about required resources and modifications to equipment and procedures. This paper reports the results of this modeling effort
Mott mechanism and the hadronic to quark matter phase transition
International Nuclear Information System (INIS)
Blaschke, D.; Reinholz, F.
1984-01-01
A unified description of both the hadronic and quark matter can be found using the technique of thermodynamic Green functions. The destruction of bound states (quark deconfinement) is related microscopically to the Mott mechanism which leads to a different behaviour of free particle energies and bound state energies if the particle density is increasing. A simple model calculation is performed to obtain a rough estimate for the critical temperature of the hadronic-quark matter phase transition
Higgs physics with hadronic signatures at ATLAS and CMS
Schroder, Matthias
2018-01-01
Precise measurement of the properties of the Higgs boson is of paramount interest in order to verify the standard model nature of the Higgs sector or discover new physics. Crucial information is obtained from investigation of hadronic final states, which offer, for example, a direct probe of the couplings to top or bottom quarks. In this article, latest results of Higgs boson measurements with hadronic signatures by ATLAS and CMS at the LHC are reviewed.
Hadronic final states and sum rules in deep inelastic processes
International Nuclear Information System (INIS)
Pal, B.K.
1977-01-01
In order to get maximum information on the hadronic final states and sum rules in deep inelastic processes, Regge phenomenology and quarks parton model have been used. The unified picture for the production of hadrons of type i as a function of Bjorken and Feyman variables with only one adjustable parameter is formulated. The results of neutrino experiments and the production of charm particles are discussed in sum rules. (author)
Heavy quarks in hadronic collisions
International Nuclear Information System (INIS)
Brodsky, S.J.; Peterson, C.
1982-03-01
It is suggested that the presence of c anti c-pairs on the 1 to 2% level in the hadron Fock state decomposition (intrinsic charm) gives a natural description of the ISR data for charm hadron production. The theoretical foundations of the intrinsic charm hypothesis together with its consequences for lepton- and hadron-induced reactions are discussed in some detail. There is no contradiction with the EMC data on F 2 /sup c/ provided the appropriate threshold dependence is taken into account
Fundamentals in hadronic atom theory
Deloff, A
2003-01-01
Hadronic atoms provide a unique laboratory for studying hadronic interactions essentially at threshold. This text is the first book-form exposition of hadronic atom theory with emphasis on recent developments, both theoretical and experimental. Since the underlying Hamiltonian is a non-self-adjoined operator, the theory goes beyond traditional quantum mechanics and this book covers topics that are often glossed over in standard texts on nuclear physics. The material contained here is intended for the advanced student and researcher in nuclear, atomic or elementary-particle physics. A good know