394 research outputs found
Electric dipole and magnetic quadrupole moments of the boson via a CP-violating vertex in effective Lagrangians
The possibility of nonnegligible electric dipole ()
and magnetic quadrupole () moments induced by the most general
vertex is examined via the effective Lagrangian technique. It is assumed
that new heavy fermions induce an anomalous CP-odd component of the
vertex, which can be parametrized by an -invariant
dimension-six operator. This anomalous contribution, when combined with the
standard model CP-even contribution, lead to CP-odd electromagnetic properties
of the boson, which are characterized by the form factors and . It is found that is divergent, whereas is finite,
which reflects the fact that the latter cannot be generated at the one-loop
level in any renormalizable theory. Assuming reasonable values for the unknown
parameters, we found that e-cm,
which is eight orders of magnitude larger than the SM prediction and close to
the upper bound derived from the neutron electric dipole moment. The estimated
size of the somewhat less-studied moment is of the order of
e-cm^2, which is fifteen orders of magnitude above the SM
contribution.Comment: 7 pages, 6 figures, REVTEX styl
Nilpotency of skew braces and multipermutation solutions of the Yang-Baxter equation
We study relations between different notions of nilpotency in the context of
skew braces and applications to the structure of solutions to the Yang-Baxter
equation. In particular, we consider annihilator nilpotent skew braces, an
important class that turns out to be a brace-theoretic analog to the class of
nilpotent groups. In this vein, several well-known theorems in group theory are
proved in the more general setting of skew braces.Comment: 18 pages. Postprint versio
Factorizations of skew braces
We introduce strong left ideals of skew braces and prove that they produce non-trivial decomposition of set-theoretic solutions of the Yang–Baxter equation. We study factorization of skew left braces through strong left ideals and we prove analogs of Itô’s theorem in the context of skew left braces. As a corollary, we obtain applications to the retractability problem of involutive non-degenerate solutions of the Yang–Baxter equation. Finally, we classify skew braces that contain no non-trivial proper characteristic ideals.Fil: Jespers, E.. Vrije Unviversiteit Brussel; BélgicaFil: Kubat, L.. Vrije Unviversiteit Brussel; BélgicaFil: Van Antwerpen, A.. Vrije Unviversiteit Brussel; BélgicaFil: Vendramin, Claudio Leandro. Institute of Mathematical Sciences at NYU Shanghai; China. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
CP-odd static electromagnetic properties of the W gauge boson and the t quark via the anomalous tbW coupling
In the framework of the electroweak chiral Lagrangian, the one-loop induced
effects of the anomalous coupling, which includes both left- and
right-handed complex components, on the static electromagnetic properties of
the boson and the quark are studied. The attention is focused mainly on
the CP-violating electromagnetic properties. It is found that the
anomalous coupling can induce both CP-violating moments of the boson,
namely, its electric dipole () and magnetic quadrupole
() moments. As far as the quark is concerned, a potentially
large electric dipole moment can arise due to the anomalous
coupling. The most recent bounds on the left- and right-handed parameters from
meson physics lead to the following estimates e-cm and e-cm, which
are 7 and 14 orders of magnitude larger than the standard model (SM)
predictions, whereas may be as large as e-cm, which is about 8
orders of magnitude larger than its SM counterpart.Comment: This paper has been merged with hep-ph/0612171 for publication in
Physical Review
Left atrial appendage thrombosis and persistent atrial fibrillation: Combined treatment with a totally thoracoscopic approach
Minimally invasive surgical ablation is generally contraindicated in patients with atrial fibrillation and thrombosis of the left atrial appendage. We have treated three of these patients using an innovative technique based on a bilateral video-thoracoscopic approach, performing a continuous encircling lesion at the pulmonary veins outflow with radio-frequency ablation, simultaneously excluding the left atrial appendage. The postoperative course was uneventful, without neurologic events and all patients maintained a stable sinus rhythm at 1-year follow-up. This procedure represents a new mini-invasive method to treat persistent atrial fibrillation when partial thrombosis of the left atrial appendage contraindicates other ablation techniques
Acute acquired immune thrombocytopenia after cardiac surgery: A challenging case
Thrombocytopenia is a common condition that recognizes an infinite number of possible causes, especially in specific settings like the one covered in this case report: the postoperative period of cardiac surgery. We report a case of an old male with multiple comorbidities who underwent a coronary angioplasty procedure and aortic valve replacement. He showed severe thrombocytopenia in the postoperative days. Differential diagnosis required a big effort, also for the experts in the field. Our goal was to aggressively treat the patient with prednisolone, platelets, and intravenous immunoglobulins to maximize the prognosis. Our patient developed no complications and was discharged successfully
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