2,478 research outputs found
Flavour physics constraints in the BMSSM
We study the implications of the presence of the two leading-order,
non-renormalizable operators in the Higgs sector of the MSSM to flavour physics
observables. We identify the constraints of flavour physics on the parameters
of the BMSSM when we: a) focus on a region of parameters for which electroweak
baryogenesis is feasible, b) use a CMSSM-like parametrization, and c) consider
the case of a generic NUHM-type model. We find significant differences as
compared to the standard MSSM case.Comment: 22 pages, 7 figure
Filaments in the edge confinement region of TJ-II
Autor colectivo: TJ-II TeamFloating potential measurements from two remote reciprocating probes in the plasma edge region of the TJ-II stellarator are analyzed using the transfer entropy, revealing the spatial dimensions and propagation properties of filamentary structures. The results are corroborated by performing simulations with a resistive MHD model and analyzing data from synthetic diagnostics. The transfer entropy captures the rotation of the filaments and allows the calculating of their rotation velocity. This deduced velocity was compared to the (known) poloidal velocity of the plasma and showed a relatively good agreement
Quartz Crystal Microbalance With Dissipation Monitoring: A Versatile Tool to Monitor Phase Transitions in Biomimetic Membranes
Solid-supported lipid membranes are popular models that connect biological and artificial materials used in bio-technological applications. Controlling the lipid organization and the related functions of these model systems entails understanding and characterizing their phase behavior. Quartz crystal microbalance with dissipation monitoring (QCM-D) is an acoustic-based surface-sensitive technique which is widely used in bio-interfacial science of solid-supported lipid membranes. Its sensitivity to mass and energy dissipation changes at the solid-lipid layer-liquid interface allows the detection of phase transformations of solid-supported membrane geometries. In this perspective, we highlight this valuable feature and its related methodology, review current advances and briefly discuss future perspectives. Furthermore, a specific example is also provided on the ability of QCM-D to detect changes in lipid organization of cholesterol containing solid-supported lipid vesicle layers (SVLs) upon the addition of aspirin
Status of Electroweak Phase Transition and Baryogenesis
I review recent progress on the electroweak phase transition and
baryogenesis, focusing on the minimal supersymmetric standard model as the
source of new physics.Comment: 10 pp, 6 figures; plenary talk given at 6th Workshop on High Energy
Physics Phenomenology, 4 Jan. 2000, Chennai, India. v.2: added reference
Comunidades indĂgenas: una expresiĂłn de la diversidad Ă©tnica y cultural en el Huila
El presente artĂculo es un avance de los resultados del proceso de a compañamiento de un grupo interdisciplinario e interinstitucional de la Universidad Surcolombiana y el INCORA a diez comunidades cordilleranas, de las etnias nasa pĂĄez, guambiana y yanaconas, asentadas en diferentes municipios del Huila, para la formulaciĂłn de sus planes de vida. Es una reflexiĂłn que intenta realizar el seguimiento al proceso de vida indĂgena. Este parte de las huellas de los ancestros, llega al presente y se proyecta al futuro de manera autĂłnoma, buscando garantizar la pervĂvencia como pueblos en el tiempo. En el trabajo se armonizaron las actividades de investigaciĂłn y de extensiĂłn, con valor educativo en la medida que fue un intercambio de conocimientos y experiencias de todos
VISIR: experiences and challenges
It is of crucial importance the integration of practical
sessions in engineering curricula owing to their significant
role in understanding engineering concepts and scientific
phenomena. However, the lack of practical sessions due
to the high costs of the equipment and the unavailability of
instructors has caused a significant declination in experimentation
in engineering education. Remote laboratories
have tackled this issues providing online reusable and
shared workbenches unconstrained by neither geographical
nor time considerations. Thereby, they have extremely proliferated
among universities and integrated into engineering
curricula over the last decade. This contribution compiles
diverse experiences based on the deployment of the remote
laboratory, Virtual Instrument Systems in Reality (VISIR),
on the practices of undergraduate engineering grades at
various universities within the VISIR community. It aims to
show the impact of its usage on engineering education concerning
the assessments of students and teachers as well. In
addition, the paper address the next challenges and future
works carried out at several universities within the VISIR
community
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at sâ=8 TeV with ATLAS
Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of sâ=8 TeV. The analysis is performed in the H â γγ decay channel using 20.3 fbâ1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp â H â γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) ââ2.9 +â3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations
Measurement of the production of a W boson in association with a charm quark in pp collisions at âs = 7 TeV with the ATLAS detector
The production of a W boson in association with a single charm quark is studied using 4.6 fbâ1 of pp collision data at sâ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26â0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio Ï(W + +cÂŻÂŻ)/Ï(W â + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the sâsÂŻÂŻÂŻ quark asymmetry
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