Have Pentaquark States Been seen?

The status of the search for pentaquark baryons is reviewed in light of new results from the first two dedicated experiments from CLAS at Jefferson Lab and of new analyses from several laboratories on the $Theta^+(1540)$. Evidence for and against two heavier pentaquark states is also discussed.Comment: Added some references, corrected typo

BlogForever D5.2: Implementation of Case Studies

This document presents the internal and external testing results for the BlogForever case studies. The evaluation of the BlogForever implementation process is tabulated under the most relevant themes and aspects obtained within the testing processes. The case studies provide relevant feedback for the sustainability of the platform in terms of potential users’ needs and relevant information on the possible long term impact

Comment on The Evidence for a Pentaquark and Kinematic Reflections

The Regge exchange model used by Dzierba et al. is shown to be questionable, since the pion pole term is not allowed. Hence the Regge amplitudes in their calculation are exaggerated. The amount of kinematic reflection in the mass spectrum of the (nK+) system, which is one decay channel of a possible pentaquark, is not well justified in the fitting procedure used by Dzierba et al., as shown by comparison with the (K+K-) invariant mass spectrum, which is one decay channel of the a_2 and f_2 tensor mesons. While kinematic reflections are still a concern in some papers that have presented evidence for the pentaquark, better quantitative calculations are needed to demonstrate the significance of this effect.Comment: Comment submitted to Phys. Rev. D (no figures

Innovative approaches to the organization of social service of elderly people in a management of the social work : regional experience

The article is devoted to a problem of formation of new system of social service, relevant for Russia, covering a general population. In these conditions the new tasks are set for management of social work. They are connected with creation and introduction in practice of social work of new technologies of work with elderly people who will be directed not only to the solution of the existing social problems, but promoting involvement of pensioners in a "active" old age. At the description of regional experiment of Krasnoyarsk Region on introduction of innovative technologies the analysis and synthesis, logical and complex approaches are used to assessment of level of social service of the elderly. In work, it is shown that the faces of the senior generation are the unprotected social group of the population of Russia. By the way it is added also the financial problems. As a solution of this problem, innovative approach is offered to the organization of social service of the elderly in management of social work of Krasnoyarsk Region. The regional experience will promote the choice of optimal model of management of social work.peer-reviewe

BlogForever D5.3: User Questionnaires and Reports

This report presents the feedback gathered from third party users during the BlogForever Case Studies. Therefore, the research framework is defined and the case studies results are presented, followed by a summary of conclusions and remarks

Experimental Outlook for the Pentaquark

A critical look is taken at both positive and null evidence for the $\Theta^+$ pentaquark. Potential problems with experiments will be discussed and the question of what conclusion can be drawn from both the positive and the null results is examined. First the question of existence of the $\Theta^+$ pentaquark is considered, followed by a discussion of new experiments that are either planned or in progress to answer questions about its mass, width and isospin. Finally, indirect evidence for the parity of the $\Theta^+$ is examined, and suggestions for experiments to measure its parity directly are given.Comment: MESON2004 conference proceedings, 10 pages, 1 figur

A Selection Rule for Multiquark Decays

By assuming SU(6)_cs symmetry for pentaquark decays one finds a selection rule, which strongly reduces the number of states able to decay into a baryon and a meson final state and allows an intriguing identification for the Theta^+ particle recently discovered with the prediction of a narrow width.Comment: 10 pages, no figure

The Evidence for a Pentaquark Signal and Kinematic Reflections

Several recent experiments have reported evidence for a narrow baryon resonance with positive strangeness ($\Theta^+$) at a mass of 1.54 GeV/$c^2$. Baryons with $S=+1$ cannot be conventional $qqq$ states and the reports have thus generated much theoretical speculation about the nature of possible $S=+1$ baryons, including a 5-quark, or pentaquark, interpretation. We show that narrow enhancements in the $K^+n$ effective mass spectrum can be generated as kinematic reflections resulting from the decay of mesons, such as the $f_2(1275)$, the $a_2(1320)$ and the $\rho_3(1690)$.Comment: 4 pages, 4 figure

A Keck Survey of Gravitational Lens Systems: I. Spectroscopy of SBS 0909+532, HST 1411+5211, and CLASS B2319+051

We present new results from a continuing Keck program to study gravitational lens systems. We have obtained redshifts for three lens systems, SBS 0909+532, HST 1411+5211, and CLASS B2319+051. For all of these systems, either the source or lens redshift (or both) has been previously unidentified. We find (z_l, z_s) = (0.830, 1.377) for SBS 0909+532; (z_l, z_s) = (0.465, 2.811) for HST 1411+5211, although the source redshift is still tentative; and (z_l1, z_l2) = (0.624, 0.588) for the two lensing galaxies in CLASS B2319+051. The background radio source in B2319+051 has not been detected optically; its redshift is, therefore, still unknown. We find that the spectral features of the central lensing galaxy in all three systems are typical of an early-type galaxy. The observed image splittings in SBS 0909+532 and HST 1411+5211 imply that the masses within the Einstein ring radii of the lensing galaxies are 1.4 x 10^{11} and 2.0 x 10^{11} h^{-1} M_sun, respectively. The resulting B band mass-to-light ratio for HST 1411+5211 is 41.3 +/- 1.2 h (M/L)_sun, a factor of 5 times higher than the average early-type lensing galaxy. This large mass-to-light is almost certainly the result of the additional mass contribution from the cluster CL 3C295 at z = 0.46. For the lensing galaxy in SBS 0909+532, we measure (M/L)_B = 4^{+11}_{-3} h (M/L)_sun where the large errors are the result of significant uncertainty in the galaxy luminosity. While we cannot measure directly the mass-to-light ratio of the lensing galaxy in B2319+051, we estimate that (M/L)_B is between 3-7 h (M/L)_sun.Comment: Accepted for publication in Astronomical Journal. 21 pages, including 7 figure

Where are the missing members of the baryon antidecuplet?

We analyze what consequences has the observation of exotic pentaquark baryons on the location of the non-exotic baryons belonging to the antidecuplet. We suggest that there must be a new nucleon state at 1650-1690 MeV and a new Sigma baryon at 1760-1810 MeV.Comment: 5 pages, 1 figure. Missing reference adde