Table of contents

The first meeting of the APS Topical Group on Hadronic Physics (`GHP') took place on 24–26 October 2004, at Fermilab. Two factors contributed to the decision to hold this meeting. First, the Topical Group on Hadronic Physics had recently been established, and there was general agreement that a conference devoted to the physics of hadrons was an important group activity. Second, many exciting new experimental results on hadron spectroscopy had been announced recently, and there was intense interest in these new developments. The meeting was very well attended, with over 120 scientists participating; this was triple our original estimate of the likely audience for this meeting.

The plenary sessions covered a broad range of topics, as we considered it important to promote communication between the communities pursuing research in different areas of hadron physics. The topics discussed included new results from RHIC on the QGP, the status of experiments on the flavour-exotic pentaquark and other new baryons, the new open-charm D_s and hidden-charm X states, conventional light quark resonances, glueballs and hybrids, and new facilities. Finally, a `town meeting' was held to discuss funding prospects for hadronic physics and related issues, which included a panel discussion with representatives from DOE, NSF and JLab. These plenary sessions were supplemented by 14 parallel sessions, giving a total of approximately 80 presentations.

To make the conference more accessible to younger researchers, as well as to simiplify administration, there was no conference fee for this meeting. This was possible as a result of the generous financial support of our hosts at Fermilab, for which we are very appreciative. We are also grateful to Larry Cardman for arranging Jlab assistance in producing and distributing the conference poster, to Gerald Ragghianti for designing the poster and proceedings cover, and to Lali Chatterjee and the Institute of Physics for arranging publication of the proceedings at no cost to the topical group. The efforts of the session organizers and chairs, which were crucial for the smooth operation of the conference, are also gratefully acknowledged. Finally, we were extremely fortunate to have the local assistance of Cynthia Sazama and Suzanne Weber at Fermilab, who dealt with the many details of conference organization with good cheer, exemplary competence and unstinting loyalty, even to the extent of sacrificing their weekends.

We hope that this first GHP conference has been a useful contribution to the field of hadron physics, and that it may encourage the organization of subsequent APS conferences on this diverse, challenging and fascinating field.

The PDF file contains a small selection of photographs from the first meeting of the APS Topical Group on Hadronic Physics.

After commenting on the state of contemporary hadronic physics and spectroscopy, I highlight four areas where the action is: searching for the relevant degrees of freedom, mesons with beauty and charm, chiral symmetry and the D_sJ levels, and X(3872) and the lost tribes of charmonium.

I report on recent studies of hadronic physics performed by the BaBar Collaboration. Emphasis is given to the measurement of the properties of newly discovered charmed hadrons and to the searches for light and heavy pentaquarks.

I report recent results on hidden charm spectroscopy from Belle. These include: observation of a near-threshold enhancement in the ωJ/ψ invariant mass distribution for exclusive B → K ωJ/ψ decays; evidence for the decay X(3872) → π⁺ π⁻ π⁰J/ψ, where the π⁺ π⁻ π⁰ invariant mass distribution has a strong peak between 750 MeV and the kinematic limit of 775 MeV, suggesting that the process is dominated by the sub-threshold decay X → ω J/ψ and the observation of a peak near 3940 MeV in the J/ψ recoil mass spectrum for the inclusive continuum process e⁺e⁻ → J/ψX. The results are based on a study of a 287 fb⁻¹ sample e⁺e⁻ annihilation data collected at center-of-mass energies around the Υ(4S) in the Belle detector at the KEKB collider.

Latest experimental results from BES in the charmonium mass region, and those from CLEO in the bottomonium and charmonium spectroscopy are reviewed.

A summary of the Tevatron's measurements and searches for pentaquarks and X(3872) are presented. No evidence for pentaquarks has been observed, while the X(3872) has been confirmed and some characterization has been performed. While the initial measurements are of a simple nature, the X(3872) behaves similarly to the ψ(2S), suggesting the X(3872) may be a form of unanticipated charmonium rather than a more exotic bound state of D mesons. In addition, a selected number of lifetime measurements of b-quark carrying hadrons are presented. While preliminary, these measurements are becoming competitive in precision with the B factories. These Proceedings end with some interesting measurements of the inclusive Pt and dijet mass cross-sections of b-quark containing jets.

I will review recent results in charmed meson spectroscopy from the Fermilab fixed target charm photo-production and hadro-production experiments, FOCUS and SELEX. FOCUS reports new measurements of the masses and widths of the D₂^*+ and D₂* mesons, evidence for D₀^*+ and D₀* broad states and a confirming observation of the D_sJ⁺(2317) and other recently observed high mass D_sJ⁺ states. SELEX has recently reported evidence for a new D_sJ⁺(2632) state in both the D_s⁺η⁰ and D⁰K⁺ final states.

The observation of the D_sJ*(2317), D_sJ(2460), and SELEX D_sJ*(2632) states with properties differing considerably from what was expected has led to a renewed interest in hadron spectroscopy. In addition to these states, non-strange partners of the D_sJ states have also been observed. Understanding the D₀* and D₁^' states can provide important insights into the D_sJ states. In this contribution I examine quark model predictions for the D₀* and D₁^' states and discuss experimental measurements that can shed light on them. I find that these states are well described as the broad, j = 1/2 non-strange charmed P-wave mesons. In the latter part of this writeup I discuss the c possibilities for the SELEX D_sJ*(2632) and measurements that can shed light on it.

The resonance D_sJ*(2317) which is considered to be the 1³P₀ state composed of charm and strange quarks has been discovered recently. The measured mass, which is about 160 MeV lower than the mass of the 1³P₀ state obtained from the potential model calculation by Godfrey and Isgur, was considered surprisingly low and attracted a lot of theoretical investigations. We calculate the mass shift of the 1³P₀ state by using the coupled channel effect. Our result shows that the coupled channel effect naturally explains the observed mass of D_sJ*(2317).

Results of the first measurement of ³P orbitally excited neutral D-meson states, D₂*⁰ and D₁⁰, produced in hadron collisions at the Tevatron are presented. Using data from the displaced track trigger, CDF II collects a large sample of these states in decay modes D*⁺ π⁻, D⁺ π⁻. Masses and widths of both states have been measured with precision better than or comparable to that of the world average.

X(3872) discovery was confirmed with the CDF II detector in p collisions. We measure its mass to be 3871.3 ± 0.7 ± 0.4 MeV/c². The source of X-mesons in the large CDF sample is resolved by studying their vertex displacement. We find 16.1 ± 4.9 ± 2.0% comes from decays of b-hadrons, and the remainder from prompt sources: either direct production or by decay of (unknown) short-lived particles. The mix of production sources is similar to that observed for the ψ(2S) charmonium state.

We report on a search for the X(3872) state using 15.1 fb⁻¹ of e⁺e⁻. annihilation data taken with the CLEO III detector in the s = 9.46–11.30 GeV region. Separate searches for the production of X(3872) in untagged γγ fusion and e⁺e⁻ annihilation following initial state radiation (ISR) are made by taking advantage of the unique correlation of J/ψ → l⁺l⁻ in X(3872) decay into π⁺π⁻J/ψ. No signals are observed in either case, and 90% confidence upper limits are established as (2J + 1)Γ_γγ(X(3872))β(X → π⁺π⁻J/ψ) < 12.9 eV and Γ_ee(X(3872))β(X → π⁺π⁻J/ψ) < 8.3eV.

The discovery of the X(3872) in the 3πJ/ψ mode is compelling evidence for its molecular nature. A successful prediction of this decay mode and other predictions concerning D* and D** molecules are reviewed.

We discuss the implications of the fact that the recently observed X(3872) and X(3940) are hybrid charmonium states. We use formalism of operator product expansion and nonrelativistic QCD to estimate their production rates in semiinclusive B decays. We express the decay rates in terms of a few nonperturbative matrix elements which eventually could be fixed by experimental measurements or calculated on the lattice. We use a simple flux tube model to estimate them and predict the branching ratio B → X(3872) + X_s.

Employing exclusive and inclusive reconstruction techniques, evidence for the B_s meson is established in 0.42 fb⁻¹ of data collected at the Υ(5S) resonance with the CLEO III detector. It is found that at the energy of the Υ(5S) resonance the B_s meson production proceeds predominantly through the creation of B_s*_s* pairs and the ratio of the B_s(*)_s(*) production to the total b quark pair production is (21 ± 3 ± 9)% (model dependent). All results are preliminary.

The analysis of 60 pb⁻¹ data collected on the ψ(3770) resonance with the CLEO-c detector has produced the first statistically significant signal for D⁺ → μ⁺ν decay and led to the measurement of the decay branching fraction β(D⁺→μ⁺νμ) = (3.5 ± 1.4 ± 0.6) × 10⁻⁴ and the pseudoscalar decay constant f_D = (202 ± 41 ± 17) MeV.

Using the data samples collected with the CDF Run II detector during 2002 and early 2003, new measurements of the production cross sections of charm and beauty hadrons at √s = 1960 GeV are presented. New measurements of the cross sections of centrally produced b hadrons and J/ψ mesons down to zero transverse momenta have been carried out. The large charm signals made available by the silicon vertex track trigger have enabled the measurement of the cross sections of D⁰, D*, D^±, and D_s mesons.

This note presents new preliminary CLEO measurements on ψ(2S) → X + J/ψ transitions and reviews final CLEO results on n³S₁ → n'³P_J, n'¹S₁ in charmonium and bottomonium.

Extending a previous analysis [1] the double charmonium production e⁺e⁻ → J/ψ(c) has been investigated in detail with a data set of 155 fb⁻¹ with the Belle detector. J/ψ production and helicity angular distributions are measured and give important information about the production mechanism. Theoretical predictions for the production cross section are one order of magnitude lower than the measurement and this discrepancy is still not understood. The process e⁺e⁻ → ψ(2S)(c) has been observed for the first time. The measured cross sections are compatible with e⁺e⁻ → J/ψ(c) production.

In a very recent update with a dataset of 285 fb^-1 strong evidence for a new charmonium state at a mass of 3.940 GeV was found.

Using 57.2 pb⁻¹ of data collected with the CLEO-c detector at the ψ(3770) resonance, we measure absolute branching fractions for three D⁰ and two D⁺ Cabibbo-allowed hadronic decay modes, and the cross section for e⁺e⁻ → D at E_cm = 3.77 GeV. We report preliminary measurements of branching fractions ℬ(D⁰ → K⁻π⁺) = (3.92 ± 0.08 ± 0.23)%, ℬ(D⁰ → K⁻π⁺π⁰) = (14.3 ± 0.3 ± 1.0)%, ℬ(D⁰ → K⁻π⁺π⁺π⁻) = (8.1 ± 0.2 ± 0.9)%, ℬ(D⁺ → K⁻π⁺π⁺) = (9.8 ± 0.4 ± 0.8)%, and ℬ(D⁺ → K_S⁰π⁺) = (1.61 ± 0.08 ± 0.15)%. and the cross sections σ(e⁺e⁻ → D) = (6.06 ± 0.13 ± 0.22) nb.

Initial running of the CLEO-c detector has provided the world's largest sample of ψ(3770) decays. Using this data sample, we have reconstructed D mesons decaying to hadronic final states and have used them to tag events with a charm-anti-charm pair. In this contribution, we present preliminary results from this data sample, which constitute a first step towards measurements of semileptonic decay form factors and the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements V_cs and V_cd with the full CLEO-c data set to be collected in the near future.

Recent measurements involving the newly discovered D_sJ particles are reported. The results of D_sJ production and decay branching fraction measurements are shown. Possible spin-parity and quark content assignments of D_sJ mesons are discussed. The results are based on a large data sample recorded by the Belle detector at the KEKB e⁺e⁻ collider.

Using the ∼ 6 pb⁻¹ of e⁺e⁻ annihilation data taken at ψ'(3686) with estimated ∼ 3.0 × 10⁻⁶ ψ' with CLEO III and CLEO-c detectors, we have searched for the h_c(1¹P₁) state of charmonium in the reaction ψ'(3686) → π⁰h_c → (γγ)(γη_c). The preliminary results are reported.

The recent observation of the h_c is an important test of QCD calculations and provides constraints on models of quarkonium spectroscopy. In this contribution I discuss some of these implications and describe methods to search for the h_c and h_b via radiative transitions and other means.

This contribution briefly discusses some new theoretical results for the properties of charmonium, especially the "higher charmonium" states above open-charm threshold. In particular we discuss the spectrum of states, open-flavor strong decays, and the surprisingly large effects of virtual decay loops of charmed meson pairs.

Using 5.46 pb⁻¹ of e⁺e⁻ annihilation data collected at the ψ(2S) withthe CLEO detector we have observed a variety of new hadronic decay modes of the ψ(2S). A comprehensive set of branching ratios and upper limits is presented.

The status of spin-exotic mesons is reviewed. There is now compelling evidence for at least three π₁ states between one and two GeV. Preliminary results from the reaction π⁻p → π⁺π⁺π⁻π⁻π⁰p show structure in the exotic waves corresponding to I^GJ^PC = 0⁻2⁺⁻.

The JETSET experiment (PS202) conducted at CERN was designed to search for gluonic resonances in the mass range between 2.1 and 2.4 GeV using the channel p → ϕϕ. This channel is OZI suppressed, thus any observed enhancement of the cross section beyond expections of theOZI rule could indicate possible resonating gluonic degrees of freedom. Infact, the measured cross section is two orders of magnitude beyond OZI expections. Subsequent spin-parity analyses have suggested a resonance with adominant J = 2 spin component and a parity of +1. Recently, another spin-parity analysis has been performed. This analysis includes the possibility of coherent interference with a scaler background. It will be summarized that the overall fit quality improves when coherent interference is included. A dominant spin component of J = 2 still emerges but a J = 4 component is also present.

Partial wave analyses have been performed on BES data to study scalar mesons. The σ peak is seen in ωπ⁺π⁻ and an accurate pole position, (541 ± 39) – i(252 ± 42) MeV is determined. There is evidence for the κ near the kπ threshold and the pole position is (760 ∼ 840) – i(310 ∼ 420) MeV. The f₀(980) is seen in both ϕπ⁺π⁻ and ϕk⁺k⁻ data, the parameters of the Flatté formula for f₀(980) are determined accurately. The f₀(1370), f₀(1500) and f₀(1710) are studied in some radiative and hadronic channels.

Two-body bound states such as mesons are described by solutions of the Bethe-Salpeter equation. We discuss recent results for the pseudoscalar and vector meson masses and leptonic decay constants, ranging from pions up to c bound states. Our results are in good agreement with data. Essential in these calculation is a momentum-dependent quark mass function, which evolves from a constituent-quark mass in the infrared region to a currentquark mass in the perturbative region. In addition to the mass spectrum, we review the electromagnetic form factors of the light mesons. Electromagnetic current conservation is manifest and the influence of intermediate vector mesons is incorporated self-consistently. The results for the pion form factor are in excellent agreement with experiment.

Radiative meson transitions in the light and heavy flavor sector are investigated in a potential quark model. Relativistic corrections and higher order diagrams are analyzed. The decay rates calculated with the relativistic corrections taken into account are in most of the cases in better agreement with the experimental values. Higher order diagrams seem to have larger a effect for the light quark decays.

The K-matrix formalism has been applied to the charm sector for the .rst time in the FOCUS Dalitz plot analyses of the D_s⁺ and D⁺ → π⁺π⁻π⁺ final states. The results, presented here, are extremely encouraging since the same K-matrix description provides a coherent picture of both two-body scattering measurements in light-quark experiments as well as charm meson decay. Such a result was not obvious beforehand. Moreover, the non-resonant component of each decay appears to be described by known two-body S-wave dynamics, without the need to include any three-body constant amplitude contribution.

Using about 60 pb^-1 of integrated e⁺e⁻ luminosity collected in the CLEO-c pilot run in the ϕ(3770) mass range we assess the yield and quality of 3-body hadronic D meson decays for Dalitz plot analyses.

Dirac's relativistic constraint dynamics have been successfully applied to obtain a covariant nonperturbative description of QED and QCD bound states. We use this formalism to describe a microscopic theory of meson-meson scattering as a relativistic generalization of the nonrelativistic quark-interchange model developed by Barnes and Swanson.

Evidence for the Θ⁺ pentaquark is still sketchy at the present time. This state, if it exists, has a small width and consequently a small production cross section. No single experiment has overwhelming evidence for the Θ⁺ and some non-observations of the Θ⁺ are difficult to understand unless this exotic baryon also has an exotic production mechanism. However, new data from the LEPS and CLAS collaborations with higher statistics are on the way, which will likely resolve the question of whether the Θ⁺ exists.

Several experimental groups have reported evidence for baryons with flavor exotic quantum numbers that cannot be explained as qqq bound states but require a minimum of five quarks - qqqq. These pentaquark states include the θ⁺, the Ξ⁻⁻ and the θ_c. The reported widths of these new states are consistent with experimental resolution and may be as narrow as a few MeV/c² or less. Prior to 2003, experimental searches for flavor exotic baryons spanning several decades yielded negative results. There have also been a number of searches carried out since the reports of these new pentaquark states that do not confirm their existence. This review of both the positive and negative reports seeks to understand the current situation regarding the experimental evidence for pentaquarks.

We discuss certain general features of the pentaquark picture for the θ, its _F partner, Ξ_3/2, and possible heavy quark analogues. Models employing spin-dependent interactions based on either effective Goldstone boson exchange or efective color magnetic exchange are also used to shed light on possible corrections to the Jaffe-Wilczek and Karliner-Lipkin scenarios. Some model-dependent features of the pentaquark picture (splitting patterns and relative decay couplings) are also discussed in the context of these models.

The enhancement in the flavour exotic NK channel seen by a number of experiments has been interpreted as a resonant pentaquark state, the Θ⁺(1540). Theoretical efforts to understand its structure, with the aim of explaining both the low mass and small decay width, have thrown up the possibility of a triquark-diquark P-wave correlation. We will discuss the constituent quark model study of Karliner and Lipkin and suggest that their P-wave excitation energy is an underestimate, a more plausible value raising the Θ mass in this model to more than 1700 MeV. We also propose on rather general grounds that these correlated quark models give rise to not only exotic baryon states, but also exotic meson states, in particular the strangeness +2, isoscalar ϑ⁺ which will decay to K⁺K⁰.

QCD instantons are known to produce deeply bound diquarks. We study whether it may be used as building blocks in the formation of multiquark states, in particular pentaquarks and dibaryons. A simple model is presented in which the lowest scalar diquark (and possibly the tensor one) can be treated as an independent "body", with the same color and (approximately) the same mass as a constituent (anti)quark. In it a new symmetry exists between states with the same number of "bodies" but different number of quarks appear, in particular the 3-"body" pentaquarks can be naturally related to some excited baryons. The limitations of this model are seen from the fact that it leads to light dibaryon H. Another reported work is based on a calculation of a large set of correlation functions for nonlocal operators with 4 to 6 light quarks in the Random Instanton Liquid Model (RILM). The effective interaction between diquarks is found to posses a strongly repulsive core, due to the Pauli principle for quark zero modes.

Given the existing empirical information about the exotic Θ⁺ baryon, we analyze possible properties of its SU(3)_F-partners, paying special attention to the nonstrange member of the antidecuplet N*. The modified πN partial-wave analysis presents two candidate masses, 1680 MeV and 1730 MeV. In both cases, the N* should be rather narrow and highly inelastic. Our results suggest several directions for experimental studies that may clarify properties of the antidecuplet baryons, and structure of their mixing with other baryons. Recent experimental evidence from the GRAAL and STAR Collaborations could be interpreted as observations of a candidate for the Θ⁺ nonstrange partner.

Recently there has been revival of interest in exotic baryon spectroscopy triggered by experimental evidence for pentaquarks containing u, d, s and c-quarks. We report results of the searches for pentaquark states in decays Θ⁻π^± and D*⁻p, D⁻p and ⁰p performed at CDF detector using 220 pb⁻¹ sample of p interactions at √s of 1.96 TeV. No evidence for narrow resonances were found in either mode.

Pentaquark states in lattice QCD probably lie close in energy to two particle scattering states. Correctly identifying the resonant state is a challenging, yet tractable, problem given the terascale computing facilities available today. We summarize the initial round of exploratory lattice calculations and discuss what should be accomplished in the next round.

Recent experimental progress and existing problems facing baryon spectroscopy are reviewed. Only those baryons containing light quarks (u, d, s) are considered here.

This talk describes progress at understanding the properties of the nucleon and its excitations from lattice QCD. I begin with a review of recent lattice results for the lowestlying states of the excited baryon spectrum. The need to approach physical values of the light quark masses is emphasized, enabling the effects of the pion cloud to be revealed. I then outline the development of techniques that will enable the extraction of the masses of the higher resonances, and describe how such calculations provide insight into the structure of the hadrons. Finally, I discuss direct probes of the quark and gluon structure of baryons through the lattice measurement of the moments of quark distributions and of Generalized Parton Distributions.

This talk will focus on recent results by the MILC collaboration from simulations of light hadrons in 2 + 1 flavor lattice QCD. We have achieved high precision results in the pseudoscalar sector, including masses and decay constants, plus quark masses and Gasser-Leutwyler parameters from well controlled chiral perturbation theory fits to our data. We also show spectroscopy results for vector mesons and baryons.

Existing determinations of the masses, widths and decay modes of low-lying excited states of the nucleon, as compiled in the Review of Particle Physics, are determined from energy-independent partial wave analyses of pion-nucleon scattering data. For the N*(1440) and most other resonances under 2 GeV, the analyses cited are the Karlsruhe-Helsinki, Carnegie Mellon-Berkeley and Kent State analyses, the latter of which used the elastic amplitudes from the other two. The data included in these analyses were published before 1980. Other analyses, notably the recent ones from George Washington University and the Pittsburgh-Argonne group, are "not used for averages, fits, limits, etc." Complete sets of measurements (differential cross sections, analyzing powers and spin rotation parameters) have been measured in the N*(1440) resonance region since 1980, culminating in the Crystal Ball program at BNL to measure all-neutral final states (charge exchange, multiple π⁰ final states, η production near threshold and inverse photoproduction). An overview of these data is presented and the case is made for a revitalized partial wave analysis effort

A large program of spin structure measurements is underway in Jefferson Lab's Hall B. Of particular interest is the first moment of the spin structure function g₁, which goes through a rapid transition from the photon point (Q² = 0), where it is constrained by the Gerasimov-Drell-Hearn sum rule, to the deep inelastic limit where it is sensitive to the nucleon spin fraction carried by quarks. One can then study the transition from hadronic to quark degrees of freedom over the whole range of Q². It is also interesting to look for the onset of quark-hadron duality in spin structure functions. We use longitudinally polarized electrons with energies from 1.6 to 5.7 GeV incident upon polarized NH₃ and ND₃ targets to investigate proton and deuteron spin observables in and above the resonance region. We present the GDH and Bjorken integrals using the 1.6 and 5.7 GeV data and comment on the validity of local quark-hadron duality over the wide kinematical range (0.05 ⩽ Q² ⩽ 4.5 GeV² and W < 3.2 GeV) covered by this experiment.

I review recent developments in quark-hadron duality in inclusive electron-nucleon scattering. Matrix elements of twist-4 operators extracted from moments of the spin-dependent g₁ structure function suggest that duality violating higher twists are small above Q² ∼ 1 GeV². The x dependence of local duality is analyzed within a quark model framework, and mechanisms are identified for spin-flavor symmetry breaking which underpin the behavior of structure functions at large x.

I review the LHPC Collaboration's lattice QCD calculations of the generalized parton distributions of the nucleon and highlight those aspects of nucleon structure best illuminated by lattice QCD, the nucleon's spin decomposition and transverse quark structure.

Beam-helicity asymmetries in the p → pπ⁺π⁻ reaction have been measured at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an unpolarized hydrogen target. The experiment covered the resonance region for center-of-mass energies between 1.35 GeV and 2.30 GeV. Here, we show a few examples out of the comprehensive data set and demonstrate the sensitivity of the helicity asymmetries to the dynamics of the reaction by comparing with the results of various phenomenological model calculations.

A narrow baryon state with strangeness S=+1 and mass M = 1555 ± 10 MeV/c², reported by the CLAS collaboration in the reaction γp → π⁺K⁻K⁺n, has been observed at Jefferson Lab using a tagged photon beam with an energy range of 3–5.47 GeV. A thorough investigation on whether background processes, such as π₂(1670) production, can reflect into the possible Θ⁺ peak was conducted by performing a partial wave analysis on the three-body mesonic background in the energy range of 4.8–5.47 GeV. The analysis also probes other possible processes, and does not find evidence for the observed signal being a result of kinematic reflection.

Elliptic flow of identified particles recently measured in Au + Au collisions at RHIC exhibits a remarkable constituent quarks scaling in the intermediate transverse momentum region. In this talk, I discuss if and how the observed constituent quark scaling indicates the deconfinement in the created system, and how much it tells us about the hadronization process.

Empirical scaling laws abstracted from observations pertaining to soft particle production in heavy ion collisions provide interesting connections with phenomena observed in elementary collisions (p+p, e⁺e⁻). Connections are made between these simple empirical rules and Landau's hydrodynamical model. The implications and problematics of the Landau initial conditions for strong interaction phenomenology are discussed, with some emphasis on their relevance to elementary collisions.

At this meeting I discussed selected bulk matter results from the RHIC experiments at Brookhaven National Laboratory. By studying the properties of the particles created we hope to gain information about the matter created in ultra-relativistic heavy-ion collisions and ultimately determine if the system ever consisted of liberated quarks and gluons.

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.

The physics of the quenching of hard jets in dense matter is briefly reviewed. This is presented within the framework of the partonic medium modification of the fragmentation functions. Modifications in both deeply inelastic scattering (DIS) off large nuclei and high-energy heavy-ion collisions are presented.

Fermilab's hadron physics research continues in all its accelerator-based programs. These efforts will be identified, and the optimization of the Fermilab schedules for physics will be described. In addition to the immediate plans, the Fermilab Long Range Plan will be cited, and the status and potential role of a new proton source, the Proton Driver, will be described.

We describe the physics capabilities and status of the MIPP experiment which is scheduled to enter its physics data taking period during December 2004–July 2005. We show some of the results obtained from the engineering run that concluded in August 2004 and point out the unique features of MIPP that make it an ideal apparatus to study non-perturbative QCD properties.

The ANDA experiment, which will be installed at the High-Energy Storage Ring (HESR) of the recently approved FAIR facility at GSI in Darmstadt, Germany, has a rich experimental program of hadron spectroscopy which includes the study of charmonium, the search for glueballs and hybrids and the investigation of in-medium modifications of hadrons as they interact with nuclear matter.

The physics goals of the GlueX experiment and theoretical expectations for exotic mesons are presented.

Because the time needed for a simulation in lattice QCD varies at a rate exceeding the fourth power of the lattice size, it is important to understand how small one can make a lattice without altering the physics beyond recognition. It is common to use a rule of thumb that the pion mass times the lattice size should be greater than (ideally much greater than) four (i.e., m_πL ≫ 4). By considering a relatively simple chiral quark model we are led to suggest that a more realistic constraint would be m_π(L − 2R) ≫ 4, where R is the radius of the confinement region, which for these purposes could be taken to be around 0.8–1.0 fm. Within the modelwe demonstrate that violating the second condition can lead to unphysical behaviour of hadronic properties as a function of pion mass. In particular, the axial charge of the nucleon is found to decrease quite rapidly as the chiral limit is approached.