1,969 research outputs found
excited states: a molecular approach with heavy-quark spin symmetry
The LHCb Collaboration has recently discovered five excited states
with masses between 3 and 3.1 GeV, four of them corroborated by the Belle
Collaboration. We analyse the dynamical generation of these states within a
molecular baryon-meson model that is consistent with both chiral and
heavy-quark spin symmetries. Earlier predictions within this model found five
states with masses below 3 GeV. Thus, in order to study the possible
identification of any of these states with the experimental ones in the correct
energy region, we explore two different regularization schemes, that is, a
modified regularization subtraction method and a cutoff regularization scheme.
We find that at least three of the dynamically generated states can be
identified with the experimental ones and have spin-parity or
Comment: 6 pages, 3 tables, 1 figure, contribution based on a keynote parallel
talk of the 8th International Conference on Quarks and Nuclear Physics
(QNP2018), November 13-17, 2018, Tsukuba (Japan
excited states within a HQSS model
We have reviewed the renormalization procedure used in the unitarized
coupled-channel model of Phys. Rev. D85 114032 (2012), and its impact in the
, , and sector, where five states have been
recently observed by the LHCb Collaboration. The meson-baryon interactions used
in the model are consistent with both chiral and heavy-quark spin symmetries
and lead to a successful description of the observed lowest-lying odd parity
resonances and , and and
resonances. We show that some (probably at least three) of
the states observed by LHCb will also have odd parity and spins and
, belonging two of them to the same HQSS multiplets that the latter strangenessless
heavy baryons.Comment: 11 pages, 3 figures, 6 tables, published in The European Physical
Journal
Scratching the Surface and Digging Deeper: Exploring Ecological Theories in Urban Soils
Humans have altered the Earth more extensively during the past 50 years than at any other time in history (Millennium Assessment 2003). A significant part of this global change is the conversion of land covers from native ecosystems to those dominated by human activities (Kareiva et al. 2007; Ellis and Ramankutty 2008). Although agricultural needs have historicall
Application of Transaction Costs to Choice of Transport Corridors
Fundamental changes suggest new approaches in the research field concerning the role and impacts of transport corridors. We argue that the changes in dynamics of the hinterlands of seaports, as well as the changes in the logistic concepts are the main reasons for redefining the transport corridors. Traditionally, the transport rates and transport costs have been used as relevant determinants of the decisions concerning the use of corridors. In practice, however, direct monetary costs do not basically determine the relative attractiveness of the transport corridor. In this paper the authors will introduce qualitatively determined transaction costs as additional determinants when analyzing the decision problem concernedtransaction costs transport corridors electronic commerce
Unfoldings of saddle-nodes and their Dulac time
In this paper we study unfoldings of saddle-nodes and their Dulac time. By
unfolding a saddle-node, saddles and nodes appear. In the first result (Theorem
A) we prove uniform regularity by which orbits and their derivatives arrive at
a node. Uniformity is with respect to all parameters including the unfolding
parameter bringing the node to a saddle-node and a parameter belonging to a
space of functions. In the second part, we apply this first result for proving
a regularity result (Theorem B) on the Dulac time (time of Dulac map) of an
unfolding of a saddle-node. This result is a building block in the study of
bifurcations of critical periods in a neighbourhood of a polycycle. Finally, we
apply Theorems A and B to the study of critical periods of the Loud family of
quadratic centers and we prove that no bifurcation occurs for certain values of
the parameters (Theorem C)
- …