1,861 research outputs found
New Constraints on General Slepton Flavor Mixing
We explore the phenomenological implications on charged lepton flavor
violating (LFV) processes from slepton flavor mixing within the Minimal
Supersymmetric Standard Model. We work under the model-independent hypothesis
of general flavor mixing in the slepton sector, being parametrized by a
complete set of dimensionless delta^AB_ij (A,B = L,R; i,j = 1, 2, 3)
parameters. The present upper bounds on the most relevant LFV processes,
together with the requirement of compatibility in the choice of the MSSM
parameters with the recent LHC and (g-2) data, lead to updated constraints on
all slepton flavor mixing parameters. A comparative discussion of the most
effective LFV processes to constrain the various generation mixings is
included.Comment: 42 pages, 19 figures. Minor changes, version to appear in PR
Updated Constraints on General Squark Flavor Mixing
We explore the phenomenological implications on non-minimal flavor violating
(NMFV) processes from squark flavor mixing within the Minimal Supersymmetric
Standard Model. We work under the model-independent hypothesis of general
flavor mixing in the squark sector, being parametrized by a complete set of
dimensionless delta^AB_ij (A,B = L, R; i,j = u, c, t or d, s, b) parameters.
The present upper bounds on the most relevant NMFV processes, together with the
requirement of compatibility in the choice of the MSSM parameters with the
recent LHC and g-2 data, lead to updated constraints on all squark flavor
mixing parameters.Comment: 30 pages, 7 figures. arXiv admin note: text overlap with
arXiv:1304.2783, arXiv:1109.623
A new species of Henneguya, a gill parasite of Astyanax altiparanae (Pisces: Characidae) from Brazil, with comments on histopathology and seasonality
A new species of Myxosporea, Henneguya chydadea, is described parasitizing the gills of Astyanax altiparanae collected from a lake on Rio das Pedras farm near Campinas, state of São Paulo, Brazil. Of the fish examined, 88.3% had gills parasitized by myxosporeans. The prevalence of the parasite ranged from 80% in the spring and fall, 93% in the summer and 100% in the winter. The parasite induced the formation of white, oval-shaped cysts measuring 40-64 ”m x 64-80 ”m which deformed the gill lamellae, compressed the capillaries, and caused retraction of the neighboring lamellae. The mature spores were elongated and had two identical, parallel elongate polar capsules. Each capsule contained a polar filament with 9-10 turns. There was no mucous envelope or iodinophilous vacuole. Morphometric differences between this parasite and other species of the genus Henneguya indicated, that he parasite observed in A. altiparanae is a new species. This is the first report of a myxosporeanparasitizing A. altiparanae.76176
Autonomous Robotic Arm Manipulation for Planetary Missions using Causal Machine Learning
Autonomous robotic arm manipulators have the potential to make planetary
exploration and in-situ resource utilization missions more time efficient and
productive, as the manipulator can handle the objects itself and perform
goal-specific actions. We train a manipulator to autonomously study objects of
which it has no prior knowledge, such as planetary rocks. This is achieved
using causal machine learning in a simulated planetary environment. Here, the
manipulator interacts with objects, and classifies them based on differing
causal factors. These are parameters, such as mass or friction coefficient,
that causally determine the outcomes of its interactions. Through reinforcement
learning, the manipulator learns to interact in ways that reveal the underlying
causal factors. We show that this method works even without any prior knowledge
of the objects, or any previously-collected training data. We carry out the
training in planetary exploration conditions, with realistic manipulator
models.Comment: 8 pages, ASTRA 2023: 17th Symposium on Advanced Space Technologies in
Robotics and Automation, 18-20 October 2023, Leiden, The Netherland
Higgs boson masses and B-physics constraints in Non-Minimal Flavor Violating SUSY scenarios
Journal of High Energy Physics 2012.5 (2012): 015 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA)We present one-loop corrections to the Higgs boson masses in the MSSM with Non-Minimal Flavor Violation. The flavor violation is generated from the hypothesis of general flavor mixing in the squark emass matrices, and these are parametrized by a complete set of ÎŽ xY ij (X, Y = L,R; i, j = t,c,u or b, s, d). We calculate the corrections to the Higgs masses in terms of these ÎŽ xY ij taking into account all relevant restrictions from B-physics data. This includes constraints from BR(B â X sÎł), BR(B s â ÎŒ +ÎŒ -) and ÎM Bs. After taking into account these constraints we find sizable corrections to the Higgs boson masses, in the case of the lightest MSSM Higgs boson mass exceeding tens of GeV. These corrections are found mainly for the low tan ÎČ case. In the case of a Higgs boson mass measurement these corrections might be used to set further constraints on ÎŽf YThe work of S.H. was supported in part by CICYT (grant FPA 2007-66387), in part by CICYT (grant FPA 2010-22163-C02-01) and by the Spanish MICINNâs Consolider-Ingenio 2010 Program under grant MultiDark CSD2009-00064. The work of M.H. and M.A.-C. was partially supported by CICYT (grant FPA2009-09017) and the Comunidad de Madrid project HEPHACOS, S2009/ESP-1473. The work of S.P. was supported by a RamĂłn y Cajal contract from MEC (Spain) (PDRYC-2006-000930) and partially by CICYT (grant FPA2009-09638), the Comunidad de AragĂłn project DCYT-DGA E24/2 and the Generalitat de Catalunya project 2009SGR502. The work is also supported in part by the European Communityâs Marie-Curie Research Training Network under contract MRTNCT-2006-035505 âTools and Precision Calculations for Physics Discoveries at Collidersâ and also by the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042
EU external policy-making and the case of Morocco: 'Realistically' dealing with authoritarianism?
The literature on the external relations of the EU often emphasises the normative nature of the Unionâs policies. It follows that specific policy initiatives such as the EuroâMediterranean Partnership (EMP) are then assessed according to normative parameters. This paper challenges this assumption and argues that a realist interpretation of the Unionâs external policies contributes to a better understanding of what the EU does abroad. In order to substantiate such theoretical claims, the paper analyses in detail the EUâs relations with the authoritarian state of Morocco and highlights how realist concerns dominate the Unionâs preoccupations to the detriment of the normative values it espouses on paper. The paper concludes by arguing that if a different theoretical framework from the mainstream normative one is used to assess the Unionâs policies, the outcome of this assessment changes quite radically. In the case of EMP, for instance, we claim that the Union has been rather successful in pursuing its material, realist interests. This has important implications for how the EU will operate when more integration on foreign policy matters occurs
Parallel active link suspension: a quarter car experimental study
In this paper, a novel electro-mechanical active suspension for cars, the Parallel Active Link Suspension (PALS), is proposed and then experimentally studied. PALS involves the introduction of a rotary-actuator-driven rocker-pushrod mechanism in parallel with the conventional passive suspension assembly, to exert an additional controlled force between the chassis and the wheel. The PALS geometric arrangement is designed and optimized to maximize the rocker torque propagation onto the tire load increment. A quarter car test rig with double wishbone suspension is utilized for the PALS physical implementation. Based on a linear equivalent model of the PALS quarter car, a conservative and an aggressive robust Hâ control schemes are synthesized separately to improve the ride comfort and the road holding, with different levels of control effort allowed in each of the control schemes. Simulations with a theoretical nonlinear model of the PALS quarter car are performed to evaluate the potential in suspension performance enhancement and power demand in the rocker actuator. Experiments with a harmonic road, a smoothed bump and hole, and swept frequency are conducted with the quarter car test rig to validate the practical feasibility of the novel PALS, the ride comfort enhancement, as well as the accuracy of the theoretical model and of a further nonlinear model in which practical features existing in the test rig are identified and included
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