891 research outputs found
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 . Evidence for
and against two heavier pentaquark states is also discussed.Comment: Added some references, corrected typo
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
Observation of an exotic S = +1 baryon in exclusive photoproduction from the deuteron
In an exclusive measurement of the reaction ÎłdâK+Kâpn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K+n invariant mass spectrum. The peak is at 1.542±0.005ââGeV/c2 with a measured width of 0.021ââGeV/c2 FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is (5.2±0.6)Ï. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1 baryon by other experimental groups
Observation of Exclusive Deeply Virtual Compton Scattering in Polarized Electron Beam Asymmetry Measurements
We report the first results of the beam-spin asymmetry measured in the reaction epâepÎł at a beam energy of 4.25 GeV. A large asymmetry with a sinÏ modulation is observed, as predicted for the interference term of deeply virtual compton scattering (DVCS) and the Bethe-Heitler process. The amplitude of this modulation is α=0.202±0.028. In leading-order and leading-twist perturbative QCD, the α is directly proportional to the imaginary part of the DVCS amplitude
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 usersâ needs and relevant information on the possible long term impact
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
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
Experimental Outlook for the Pentaquark
A critical look is taken at both positive and null evidence for the
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
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 is
examined, and suggestions for experiments to measure its parity directly are
given.Comment: MESON2004 conference proceedings, 10 pages, 1 figur
The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress
Experimental emotional stress which can produce various disorders of cardiac rhythm: sinus tachycardia, atrial fibrillation, ventricular, extrasystoles and paroxysmal ventricular tachysystoles was studied. In these conditions the adrenalin content in the blood and myocardium is increased 3 to 4 times. It is found that moderate motor activity leads to a relative decrease of adrenalin in the myocardium and arrest of cardiac arrhythmias
- âŠ