HADRON SPECTROSCOPY: Eleventh International Conference on Hadron Spectroscopy
814(2006); http://dx.doi.org/10.1063/1.2176463View Description Hide Description
QCD nonrelativistic effective field theories (NREFT) are the modern and most suitable frame to describe heavy quarkonium properties. Here I summarize few relevant concepts and some of the interesting physical applications (spectrum, decays, production) of NREFT.
814(2006); http://dx.doi.org/10.1063/1.2176464View Description Hide Description
There has been a renaissance in hadron spectroscopy during the last couple of years. Long lost states have been tracked down. Unexpected states are showing up all over, and numerous measurements with unprecedented precision are being reported. A review is presented.
814(2006); http://dx.doi.org/10.1063/1.2176465View Description Hide Description
The scenario of heavy quark meson spectroscopy underwent recently a major revolution, after the observation of BABAR and CLEO, confirmed by BELLE, of DsJ L=1 excited states, and by further evidences by SELEX. These experimental results have cast doubts on the incarnations of the ideas of Heavy Quark Effective Theory in heavy quark spectroscopy. I shall review the status of experimental data, discuss implications and sketch an outlook.
814(2006); http://dx.doi.org/10.1063/1.2176466View Description Hide Description
To deepen our understanding of the properties and structure of matter, new large‐scale facilities are under construction or in preparation worldwide that provide for novel research capabilities in many areas of science.
The GSI‐Darmstadt laboratory together with the international user community, has developed the concept for such a facility to broadly address frontiers in strong‐interaction physics and in the general research with intense ion beams. The new facility builds, and substantially expands, on the present accelerator system. Primary beams of high‐energy ions, and secondary beams including antiprotons and beams of short‐lived nuclei, together with an intricate system of beam‐storage and experimental rings, are its key features.
This report provides a short overview of the science motivation of the hadron community for the facility, as well as of its technical layout and performance characteristics.
814(2006); http://dx.doi.org/10.1063/1.2176467View Description Hide Description
High quality polarized electron beams at Jefferson Lab make possible precision measurelaments of hadronic properties in the regime of strongly interacting QCD. We will describe a few programs at Jefferson Lab that are making measurements that link the basic static properties of hadrons to their quark sub‐structure. For example, parity‐violating electron proton elastic scattering probes the spatial distribution of strange quarks in the nucleon. The nucleon‐Delta transition form factors give us information about the deformation of nucleons and Deltas. Finally, new high statistics measurements of photons scattering off proton and deuteron targets are used to set upper limits on the production of exotic baryons with strangeness S=+1. These examples will be used to illustrate the capabilities and focus of the experimental program at JLab.
814(2006); http://dx.doi.org/10.1063/1.2176468View Description Hide Description
We summarize some persistent problems in scalar spectroscopy and discuss what could be learned here from charmless B‐decays. Recent experimental results are discussed in comparison with theoretical expectations: a simple model based on penguin dominance leads to various symmetry relations in good agreement with recent data; a factorisation approach yields absolute predictions of rates. For more details, see .
814(2006); http://dx.doi.org/10.1063/1.2176469View Description Hide Description
Recent results from BES and CLEOc experiments on hadron spectroscopy and charmonium decays using J/ψ, ψ′ and ψ″ data samples collected in e+e− annihilation are reviewed, including the observation of X(1835) in J/ψ → γπ+π−η′, study of the scalar particles in J/ψ radiative and hadronic decays, as well as in χ c0 hadronic decays, and the study of the “ρπ puzzle” in J/ψ, ψ′, and ψ″ decays.
814(2006); http://dx.doi.org/10.1063/1.2176470View Description Hide Description
Both σ and κ are well established from E791 data on D → 3π and Ds → Kππ and BES II data on J/Ψ → ωπ+π− and K+K −π+π−. Fits to these data are accurately consistent with ππ and Kπ elastic scattering when one allows for the Adler zero which arises from Chiral Symmetry Breaking. The phase variation with mass is also consistent between elastic scattering and production data.
814(2006); http://dx.doi.org/10.1063/1.2176471View Description Hide Description
The KLOE experiment is currently taking data at the electron‐positron collider DAΦNE, the Frascati φ‐factory. At the end of this run, we expect to have integrated 2.5 fb−1 of collisions at center of mass energy W ∼ M φ. Large samples of light pseudoscalar and scalar mesons are produced through φ radiative decays. A summary of the measurements in progress on the previously collected 450 pb−1 allows us to quote the expectations on the entire sample. KLOE has also proven the feasibility of precise measurement of the hadronic cross‐section σ(e+e− → π+π−) in the region , extracting it by the measurement of the π+π−γ cross section at small photon angles. Prospects for the entire sample and the feasibility to extend such a measurement down to threshold are presented.
814(2006); http://dx.doi.org/10.1063/1.2176472View Description Hide Description
Charm meson decay dynamics have been studied extensively over the last decade. Recently, B meson decay dynamics have also been analyzed. We describe the Dalitz‐plot analysis technique which has been applied by many experiments to three‐body D and B decays. We discuss results from the E791, FOCUS, CLEO, BABAR and BELLE experiments. These studies probe a variety of physics including charmless B‐decay, doubly‐Cabibbo suppressed decays, CP violation and T violation, the properties of established light mesons, charm spectroscopy and the properties of ππ, Kπ and KK S‐wave states.
814(2006); http://dx.doi.org/10.1063/1.2176473View Description Hide Description
The AdS/CFT correspondence has led to important insights into the properties of quantum chromodynamics even though QCD is a broken conformal theory. We have recently shown how a holographic model based on a truncated AdS space can be used to obtain the hadronic spectrum of light qq̄, qqq and gg bound states. Specific hadrons are identified by the correspondence of string modes with the dimension of the interpolating operator of the hadron’s valence Fock state, including orbital angular momentum excitations. The predicted mass spectrum is linear M ∝ L at high orbital angular momentum, in contrast to the quadratic dependence M 2 ∝ L found in the description of spinning strings. Since only one parameter, the QCD scale Λ QCD , is introduced, the agreement with the pattern of physical states is remarkable. In particular, the ratio of Δ to nucleon trajectories is determined by the ratio of zeros of Bessel functions. The light‐front quantization of gauge theories in light‐cone gauge provides a frame‐independent wavefunction representation of relativistic bound states, simple forms for current matrix elements, explicit unitarity, and a trivial vacuum. The light‐front Fock‐state wavefunctions encode the bound state properties of hadrons in terms of their quark and gluon degrees of freedom at the amplitude level. One can also use the extended AdS/CFT space‐time theory to obtain a model for hadronic light‐front wavefunctions, thus providing a relativistic description of hadrons in QCD at the amplitude level. The model wavefunctions display confinement at large inter‐quark separation and conformal symmetry at short distances. In particular, the scaling and conformal properties of the LFWFs at high relative momenta agree with perturbative QCD. These AdS/CFT model wavefunctions could be used as an initial ansatz for a variational treatment of the light‐front QCD Hamiltonian. We also show how hadron form factors in both the space‐like and time‐like regions can be predicted.
814(2006); http://dx.doi.org/10.1063/1.2176474View Description Hide Description
Recent results on finite temperature and/or density lattice QCD are reviewed. Lattice techniques and some previous results are shortly discussed. New results for physical quark masses are presented. The critical endpoint, pressure, energy density, entropy density, speed of sound and quark number susceptibilities are determined.
814(2006); http://dx.doi.org/10.1063/1.2176475View Description Hide Description
BNL experiment E852 has discovered several light‐quark exotic mesons. The nature of those states is still under debate but their existence has been established. It is likely that the first few members of the 1 P hybrid meson multiplet have been observed.
814(2006); http://dx.doi.org/10.1063/1.2176476View Description Hide Description
Today, hadron physics research occurs at Fermilab as parts of broader experimental programs. This is very likely to be the case in the future. Thus, much of this presentation focuses on our vision of that future — a future aimed at making Fermilab the host laboratory for the International Linear Collider (ILC). Given the uncertainties associated with the ILC — the level of needed R&D, the ILC costs, and the timing — Fermilab is also preparing for other program choices. I will describe these latter efforts, efforts focused on a Proton Driver to increase the numbers of protons available for experiments. As examples of the hadron physics which will be coming from Fermilab, I summarize three experiments: MIPP/E907 which is running currently, and MINERνA and Drell‐Yan/E906 which are scheduled for future running periods. Hadron physics coming from the Tevatron Collider program will be summarized by Arthur Maciel in another talk at Hadron05.
814(2006); http://dx.doi.org/10.1063/1.2176477View Description Hide Description
We do meson spectroscopy by studying the behavior of S‐matrix poles in the complex‐energy plane, as a function of the coupling strength for 3 P 0 quark‐pair creation. Thereto, a general formula for non‐exotic hadron‐hadron scattering involving arbitrary quark confinement is used, which can be applied to all flavors. We find two distinct types of poles, which we call confinement and continuum poles, respectively. Together, they suffice to understand the experimental meson spectrum.
814(2006); http://dx.doi.org/10.1063/1.2176478View Description Hide Description
We report recent results on the properties of the X(3872) produced via the B → KX(3872) decay process in the Belle detector. We compare these properties with the expectations for possible assignments. The discoveries by Belle of other new particles : Y(3940), X(3940) and Z(3931) are briefly reviewed as well as the observation of an isotriplet of excited charmed baryons.
814(2006); http://dx.doi.org/10.1063/1.2176479View Description Hide Description
The COMPASS experiment has obtained first physics results in the field of polarized distribution functions for quarks and gluons using muon scattering off polarized deuterons. The analysis using open charm production and pairs of high pT hadrons is presented. We also have used a transversely polarized target to address transverse information for quarks inside the nucleon. In addition, a pilot run with incoming pions taken late 2004 will give first information on the pion polarizabilities and hadron resonances. The physics prospects from this run as well as from future data taking in this field are also outlined.
814(2006); http://dx.doi.org/10.1063/1.2176480View Description Hide Description
One of the unanswered and most fundamental questions in physics regards the nature of the confinement mechanism of quarks and gluons in quantum chromodynamics (QCD). Exotic hybrid mesons manifest gluonic degrees of freedom and their detailed spectroscopy will provide the precision data necessary to test assumptions in lattice QCD and the specific phenomenology leading to confinement. Photoproduction is expected to be a particularly effective manner to produce exotic hybrids, however, existing data using photon beams are sparse. At Jefferson Laboratory, plans are underway by the GlueX Collaboration to use the coherent bremsstrahlung technique to produce a linearly polarized photon beam. A solenoid‐based hermetic detector will be used to collect data on meson production and decays with statistics that will exceed existing photoproduction data by several orders of magnitude after the first year of running. In order to reach the ideal photon energy of 9 GeV required for these studies, the energy of the Jefferson Laboratory electron accelerator, CEBAF, will be doubled from its current maximum energy of 6 GeV to 12 GeV. The physics motivating the search and the status of the project are reviewed.
814(2006); http://dx.doi.org/10.1063/1.2176481View Description Hide Description
We review some selected experimental results achieved at the synchrotrons CELSIUS in Sweden and COSY in Germany. They concentrate on meson production with emphasis on the underlying quark structure. The project WASA at COSY is discussed and the search for symmetry breaking in decays of η and η′ mesons is highlighted.