51,249 research outputs found
Baryon states with open beauty in the extended local hidden gauge approach
In this paper we examine the interaction of \bar B N, \bar B \Delta, \bar B^*
N and \bar B^* \Delta states, together with their coupled channels, using a
mapping from the light meson sector. The assumption that the heavy quarks act
as spectators at the quark level automatically leads us to the results of the
heavy quark spin symmetry for pion exchange and reproduces the results of the
Weinberg Tomozawa term, coming from light vector exchanges in the extended
local hidden gauge approach. With this dynamics we look for states dynamically
generated from the interaction and find two states with nearly zero width,
which we associate to the \Lambda_b(5912) and \Lambda_b(5920) states. The
states couple mostly to \bar B^* N, which are degenerate with the Weinberg
Tomozawa interaction. The difference of masses between these two states, with
J=1/2, 3/2 respectively, is due to pion exchange connecting these states to
intermediate \bar B N states. In addition to these two \Lambda_b states, we
find three more states with I=0, one of them nearly degenerate in two states of
J=1/2,3/2. Furthermore we also find eight more states in , two of them
degenerate in J=1/2, 3/2, and other two degenerate in J=1/2, 3/2, 5/2.Comment: 26 pages, 9 figures, 24 table
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A Deep Learning Approach to Examine Ischemic ST Changes in Ambulatory ECG Recordings.
Patients with suspected acute coronary syndrome (ACS) are at risk of transient myocardial ischemia (TMI), which could lead to serious morbidity or even mortality. Early detection of myocardial ischemia can reduce damage to heart tissues and improve patient condition. Significant ST change in the electrocardiogram (ECG) is an important marker for detecting myocardial ischemia during the rule-out phase of potential ACS. However, current ECG monitoring software is vastly underused due to excessive false alarms. The present study aims to tackle this problem by combining a novel image-based approach with deep learning techniques to improve the detection accuracy of significant ST depression change. The obtained convolutional neural network (CNN) model yields an average area under the curve (AUC) at 89.6% from an independent testing set. At selected optimal cutoff thresholds, the proposed model yields a mean sensitivity at 84.4% while maintaining specificity at 84.9%
and cross sections
Inspired by the recent findings of the two states in the
mass spectrum at LHCb, we investigate the elastic and inelastic cross sections
of the , , and channels within the
constraints from heavy quark spin and flavour symmetry. The () bound states predicted in earlier
works should be accessible in elastic and/or inelastic processes of the and/or ( and/or ) interactions.Comment: Minor correction
Description of as a system with the fixed center approximation
We study the system with an aim to describe the
resonance. The chiral unitary approach has achieved success in a description of
systems of the light hadron sector. With this method, the system in
the isospin sector , is found to be a dominant component of the resonance. Therefore, by regarding the system as a cluster,
the resonance, we evaluate the system applying the
fixed center approximation to the Faddeev equations. We construct the
unitarized amplitude using the chiral unitary approach. As a result, we find a
peak in the three-body amplitude around 1739 MeV and a width of about 227 MeV.
The effect of the width of and is also discussed. We
associate this peak to the which has a mass of MeV
and a width of MeV
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