Hadron

Tracing the historical development of quantum physics, the author describes the baffling and seemingly lawless world of leptons, hadrons, gluons and quarks and provides a lucid and exciting guide for the layman to the world of infinitesimal particles. 

The Large Hadron Collider is an accelerator scheduled for completion in the year 2005 at the CERN laboratory near Geneva Switzerland. It will accelerate protons to an energy of 8 TeV. At that energy, the protons will have a speed only about one part in 130 million slower than the speed of light. 

Jorgensen CK (1981) The Conditions for Total Symmetry Stabilizing Molecules, Atoms, Nuclei and Hadrons. 43 1-36... 

CERN s Large Hadron Collider (LHC) project at http //lcg.web.cern.ch/LCG/... 

Rekalo, M.P. (1978) Scattering of polarized leptons by hadrons and the anapole moment of leptons and... 

Koch W, Lutz O, Nolle A (1978) Z Phys A Hadrons Nucl 289 17... 

H. Reeves, in F. Sanchez, M. Collados and R. Rebolo (eds.), Observational and Physical Cosmology, Cambridge University Press 1990, p. 73, includes a description of the physics of the quark-hadron phase transition. 

Quark model of hadrons (Gell-Mann, Zweig). 

Hadron therapy, 175 Heterodyne interferometry, 72 High-order harmonic generation, 65 HiPER, 124 Hollow fiber, 167 Hot electrons, 174... 

From this expression we can obtain the value of Tc corresponding to a given value of L. For L 1 fm, which is a value of the order of confining lengths for hadrons, we obtain Tc 0.438 /m 1 87.6 MeV. This gives us a crude estimate of the Casimir contribution of a single quark flavor for the deconfining transition for hadrons. 

Remarkably, the Wigner distribution could be observed in a number of systems by physical experiments and computer simulations evading the whole quantum world from atomic nuclei to the hydrogen atom in a magnetic field to the metal-insulator transition (Guhr, Muller-Groeling and Weidenmuller, 1998). In this contribution we address the situation in QCD and in hadrons. 

Taking the experimentally measured mass spectrum of hadrons up to 2.5 GeV from the Particle Data Group, Pascalutsa (2003) could show that the hadron level-spacing distribution is remarkably well described by the Wigner surmise for / = 1 (see Fig. 6). This indicates that the fluctuation properties of the hadron spectrum fall into the GOE universality class, and hence hadrons exhibit the quantum chaos phenomenon. One then should be able to describe the statistical properties of hadron spectra using RMT with random Hamiltonians from GOE that are characterized by good time-reversal and rotational symmetry. 

Figure 6. Histograms of the nearest-neighbor mass spacing distribution for hadron states with same quantum numbers. Curves represent the Poisson (dashed) and Wigner (solid) distributions. Taken from Ref. (Pascalutsa, 2003).

Abstract. Low-momentum quark determinant and effective action in the presence of current quark mass and external flavor fields is derived. The results of the calculations of various correlators are briefly presented. We conclude that, this approach is a reliable tool for the hadron physics, especially including strange quarks. 

The fermionic determinant Detiow averaged over instanton anti-instanton positions, orientations and sizes leads to a partition function of light quarks Z. Then the properties of the hadrons and their interactions are concentrated in the QCD effective action written in terms of the quasiparticles. This approach leads to the Diakonov-Petrov(DP) effective action (D.I. Diakonov et.al., 1996). It was shown that DP effective action is a good tool in the chiral limit but fails beyond this limit, checked by the calculations of the axial-anomaly low energy theorems (M.M. Musakhanov et.al., 1997 E. Di Salvo et.al., 1998). 

Proposed approach provides reliable tool in hadron physics with the promising perspective of the application to strange quarks. 

Abstract. The —> um° decay is studied using the method of phenomenological chiral Lagrangians. Obtained in the framework of this method the expression of weak hadronic currents between vector and pseudoscalar mesons has been checked and it is shown that this decay channel proceeds only due to the — p - mixing diagram. 

Here, we consider the (ft —> unr° decay by the method of phenomenological chiral Lagrangians(PCL s)(Weinberg,1967). Studies of this decay channel is of interest in this model for the following reasons First, this decay channel is a unique laboratory for verification of weak hadron currents between pseudoscalar and vector meson states which was obtained earlier (Nasriddinov, 1998) within the formalism of phenomenological chiral Lagrangians... 

According to the expression for weak hadronic currents between pseudoscalar and vector meson states (f), the Born amplitude of this decay is equal to zero, since the structure constants /i3j = fs3i = 0, (in other words, the current // responsible for the direct — um° decay (FIG.f) is zero). 

The structure constants of the SU(3) group responsible for this transition are equal to zero /391 = /3i0i = /39s = /3108 = 0. It should be noted that the diagrams 2 and 3 do not contribute to the partial width of the 0 — con0 decay channel which is obvious also due to the hadronic flavor conservation principle. According to the expression (2),also the anomalous diagram (FIG.4.) does not contribute to the partial width of the 0 —> W7T° decay because... 

Accurate theoretical prediction of mass spectra and other properties of hadrons containing heavy quarks is important for mass spectra of hadrons for forthcoming experiments on the study of their properties. At present such facilities as Tevatron, LHC and JHF will have the opportunity to produce hadrons with one or more heavy quarks. The successful experiments at the Collider Detector at Fermilab Collaboration on the observation of the Bc meson (Abe et. ah, 1998) gives some hope to observe heavy quarkonia, also. 

At present a considerable amount of data is available for heavy flavored mesons, and it is expected that the experimental observation of heavy flavored hadrons at modern hadron colliders with high luminosity such as Tevatron, LHC and RHIC will further increase our knowledge of this family of hadrons. 

Despite the considerable progress made in the spectroscopy of hadrons containing heavy quarks within the framework of potential models and other approaches, most of the work on the calculation of mass spectra... 

Thus we have treated the chaotic dynamics of the quarkonium in a time periodic field. Using the Chirikov s resonance overlap criterion we obtain estimates for the critical value of the external field strength at which chaotization of the quarkonium motion will occur. The experimental realization of the quarkonium motion under time periodic perturbation could be performed in several cases in laser driven mesons and in quarkonia in the hadronic or quark-gluon matter. 

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