22 research outputs found
Workersâ satisfaction vis-Ă -vis environmental and socio-morphological aspects for sustainability and decent work
This study examines worker satisfaction vis-Ă -vis outdoor places in terms of their environmental and socio-morphological aspects. Numerous studies have considered decent work as the eighth goal of sustainable development. However, it is worth investigating outdoor workersâ satisfaction with a view to the practical design of the surrounding context that supports their work in outdoor places. Using bibliometric analysis, this study investigates possible approaches toward providing decent work in a public place in Cairo as a case study, focusing on outdoor workersâ satisfaction. In the bibliometric analysis, this study used query settings in the Scimago database to search for manuscripts published in the previous five years. The result yielded 195 manuscripts that were filtered down to 50 manuscripts and then grouped using VOSviewr Software. Environmental noise and heat assessment analyses were performed using noise level measurements, remote sensing, and the Grasshopper platform. Further, we conducted an ethnographic study employing 77 participant observations. The results show that work hours and time affect worker satisfaction, as do environmental conditions, particularly noise and heat. However, unexpected findings from participant observation in this study do not accord with findings in other scholarly sources, where other observers find workers neither satisfied nor dissatisfied with the spatial morphology in the case study. Per this study, the alignment of worker satisfaction with convenient socio-morphological tangible elements of the workplace and with other environmental aspects should be attained in both specified replicable methods to engender decent work for outdoor workers
X(3872): Hadronic Molecules in Effective Field Theory
We consider the implications from the possibility that the recently observed
state X(3872) is a meson-antimeson molecule. We write an effective Lagrangian
consistent with the heavy-quark and chiral symmetries needed to describe
X(3872). We claim that if X(3872) is a molecular bound state of D^*0 and
anti-D^0 mesons, the heavy-quark symmetry requires the existence of the
molecular bound state X_b of B^*0 and anti-B^0 with the mass of 10604 MeV.Comment: 12 pages, 1 figure, 1 table, RevTe
Heavy Quarkonium Physics from Effective Field Theories
I review recent progress in heavy quarkonium physics from an effective field
theory perspective. In this unifying framework, I discuss advances in
perturbative calculations for low-lying quarkonium observables and in lattice
calculations for high-lying ones, and progress and lasting puzzles in
quarkonium production.Comment: Plenary talk at the 4th International Conference on Quarks and
Nuclear Physics (QNP06), 5-10 June 2006, Madrid, Spain; 6 pages, 1 figure,
EPJ styl
Hidden charm and bottom molecular states
We investigate heavy quark symmetries for heavy light meson-antimeson systems in a contact-range effective field theory. In the SU(3) light flavor limit, the leading order Lagrangian respecting heavy quark spin symmetry contains four independent counter-terms. Neglecting 1/mQ corrections, three of these low energy constants can be determ1ined by theorizing a molecular description of the X(3872) and Zb(10610) states. Thus, we can predict new hadronic molecules, in particular the isovector charmonium partners of the Zb(10610) and the Zb(10650) states. We also discuss hadron molecules composed of a heavy meson and a doubly-heavy baryon, which would be related to the heavy meson-antimeson molecules thanks to the heavy antiquark-diquark symmetry. Finally, we also study the X(3872)âD0DÂŻ0Ï0 decay, which is not only sensitive to the short distance part of the X(3872) molecular wave function, as the J/ÏÏÏ and J/Ï3Ï X(3872) decay modes are, but it is also affected by the long-distance structure of the resonance. Furthermore, this decay might provide some information on the interaction between the DDÂŻ charm mesons
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Detecting the long-distance structure of the X(3872)
We study the decay within a molecular picture for the state. This decay mode is more sensitive to the long-distance structure of the resonance than its and decays, which are mainly controlled by the details of the wave function at short distances. We show that the final state interaction can be important, and that a precise measurement of this partial decay width can provide valuable information on the interaction strength between the charm mesons
Decay widths of the spin-2 partners of the X(3872)
We consider the X(3872) resonance as a JPC=1++ DDÂŻâ hadronic molecule. According to heavy quark spin symmetry, there will exist a partner with quantum numbers 2++, X2, which would be a DâDÂŻâ loosely bound state. The X2 is expected to decay dominantly into DDÂŻ, DDÂŻâ and DÂŻDâ in d-wave. In this work, we calculate the decay widths of the X2 resonance into the above channels, as well as those of its bottom partner, Xb2, the mass of which comes from assuming heavy flavor symmetry for the contact terms. We find partial widths of the X2 and Xb2 of the order of a few MeV. Finally, we also study the radiative X2âDDÂŻâÎł and Xb2âBÂŻBâÎł decays. These decay modes are more sensitive to the long-distance structure of the resonances and to the DDÂŻâ or BBÂŻâ final state interaction
Is X(3872) {\sl Really} a Molecular State?
After taking into account both the pion and sigma meson exchange potential,
we have performed a dynamical calculation of the system.
The meson exchange potential is repulsive from heavy quark symmetry
and numerically important for a loosely bound system. Our analysis disfavors
the interpretation of X(3872) as a loosely bound molecular state if we use the
experimental coupling constant and a reasonable cutoff
around 1 GeV, which is the typical hadronic scale. Bound state solutions with
negative eigenvalues for the system exist only with either a
very large coupling constant (two times of the experimental value) or a large
cutoff ( GeV or GeV). In contrast, there
probably exists a loosely bound S-wave molecular state. Once
produced, such a molecular state would be rather stable since its dominant
decay mode is the radiative decay through . Experimental
search of these states will be very interesting.Comment: 11 pages, 7 figures, 9 tables. The version to appear in EPJ