3,525 research outputs found
On Possibility of Detecting the E-E- -> W-W- Process in the Standard Model
We examine the e-e- -> W-W- lepton number violating process in the frame of
the Standard Model with additional right-handed neutrino singlets. We give
results in the framework of the `see-saw' as well as other models, where there
is no relation between neutrino masses and the mixing matrix elements. The
cross section for the `see-saw' models is negligible because they predict in a
natural way very small electron-heavy neutrino mixing angles. However, there
exist other models, in which the electron-heavy neutrino mixing angles are free
parameters and can be large. Taking into account the present experimental
bounds on mixing angles the large cross section for the e-e- -> W-W- is still
acceptable.Comment: 16 pages, LATEX file and 4 tar-compressed uuencoded figure
The 10th Biennial Hatter Cardiovascular Institute workshop: cellular protection—evaluating new directions in the setting of myocardial infarction, ischaemic stroke, and cardio-oncology
Due to its poor capacity for regeneration, the heart is particularly sensitive to the loss of contractile cardiomyocytes. The onslaught of damage caused by ischaemia and reperfusion, occurring during an acute myocardial infarction and the subsequent reperfusion therapy, can wipe out upwards of a billion cardiomyocytes. A similar program of cell death can cause the irreversible loss of neurons in ischaemic stroke. Similar pathways of lethal cell injury can contribute to other pathologies such as left ventricular dysfunction and heart failure caused by cancer therapy. Consequently, strategies designed to protect the heart from lethal cell injury have the potential to be applicable across all three pathologies. The investigators meeting at the 10th Hatter Cardiovascular Institute workshop examined the parallels between ST-segment elevation myocardial infarction (STEMI), ischaemic stroke, and other pathologies that cause the loss of cardiomyocytes including cancer therapeutic cardiotoxicity. They examined the prospects for protection by remote ischaemic conditioning (RIC) in each scenario, and evaluated impasses and novel opportunities for cellular protection, with the future landscape for RIC in the clinical setting to be determined by the outcome of the large ERIC-PPCI/CONDI2 study. It was agreed that the way forward must include measures to improve experimental methodologies, such that they better reflect the clinical scenario and to judiciously select combinations of therapies targeting specific pathways of cellular death and injury
Mesures de vies moyennes par effet Doppler
Des vies moyennes de niveaux nucléaires ont été déterminées par la méthode de l'effet Doppler. Les rayonnements gamma de désexcitation ont été détectés dans des compteurs Ge(Li). Des vies moyennes ont été obtenues pour les niveaux 0,953 MeV de 12B et 6,44 MeV de 14N
Extraction of the Ratio of the N^*(1535) Electromagnetic Helicity Amplitudes from Eta Photoproduction off Neutrons and Protons
Using the recent precise measurements of eta photopro- duction in proton and
deuteron targets, we extract the ratio of the helicity amplitudes A^n_1/2 /
A^p_1/2, for the excitation of N^*(1535), in the effective Lagrangian approach,
It is fairly model-independent, free from the final-state interaction effects,
and negative as predicted by the quark models. We stress the importance of
polarization observables in further elucidation of the N^*(1520)
photoexcitation amplitudes.Comment: 4 figures. It will be published in Phys. Lett.
Quadratic electroweak corrections for polarized Moller scattering
The paper discusses the two-loop (NNLO) electroweak radiative corrections to
the parity violating electron-electron scattering asymmetry induced by squaring
one-loop diagrams. The calculations are relevant for the ultra-precise 11 GeV
MOLLER experiment planned at Jefferson Laboratory and experiments at
high-energy future electron colliders. The imaginary parts of the amplitudes
are taken into consideration consistently in both the infrared-finite and
divergent terms. The size of the obtained partial correction is significant,
which indicates a need for a complete study of the two-loop electroweak
radiative corrections in order to meet the precision goals of future
experiments
Measurement of fast and thermal neutron flux from the d + D reaction using the activation method
LPSC-acc ;
IMproving Preclinical Assessment of Cardioprotective Therapies (IMPACT) criteria: guidelines of the EU-CARDIOPROTECTION COST Action
Cardioprotection; Drug development; InfarctionCardioprotección; Desarrollo de fármacos; InfartoCardioprotecció; Desenvolupament de fà rmacs; InfartAcute myocardial infarction (AMI) and the heart failure (HF) which may follow are among the leading causes of death and disability worldwide. As such, new therapeutic interventions are still needed to protect the heart against acute ischemia/reperfusion injury to reduce myocardial infarct size and prevent the onset of HF in patients presenting with AMI. However, the clinical translation of cardioprotective interventions that have proven to be beneficial in preclinical animal studies, has been challenging. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic in vivo preclinical assessment of the efficacy of promising cardioprotective interventions prior to their clinical evaluation. To address this, we propose an in vivo set of step-by-step criteria for IMproving Preclinical Assessment of Cardioprotective Therapies (‘IMPACT’), for investigators to consider adopting before embarking on clinical studies, the aim of which is to improve the likelihood of translating novel cardioprotective interventions into the clinical setting for patient benefit.This article is based on the work from COST Action EU-CARDIOPROTECTION CA16225 supported by COST (European Cooperation in Science and Technology). DJH is supported by the Duke-National University Singapore Medical School, Singapore Ministry of Health’s National Medical Research Council under its Clinician Scientist-Senior Investigator scheme (NMRC/CSA-SI/0011/2017) and Collaborative Centre Grant scheme (NMRC/CGAug16C006). SL is supported by grants from the South African Department of Science and Technology and the South African National Research Foundation. SMD is supported by grants from the British Heart Foundation (PG/19/51/34493 and PG/16/85/32471). GH is supported by the German Research Foundation (SFB 1116 B8). MRM is supported by the Spanish Institute of Health Carlos III (FIS PI19/01196 and CIBER-CV). RS is supported by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) [Project number 268555672—SFB 1213, Project B05]. PF is supported by the National Research, Development and Innovation Office of Hungary (Research Excellence Program—TKP, National Heart Program NVKP 16-1-2016-0017) and by the Higher Education Institutional Excellence Program of the Ministry of Human Capacities in Hungary, within the framework of the Therapeutic Development thematic program of the Semmelweis University
Bulk Majorons at Colliders
Lepton number violation may arise via the spontaneous breakdown of a global
symmetry. In extra dimensions, spontaneous lepton number violation in the bulk
implies the existence of a Goldstone boson, the majoron J^(0), as well as an
accompanying tower of Kaluza-Klein (KK) excitations, J^(n). Even if the
zero-mode majoron is very weakly interacting, so that detection in low-energy
processes is difficult, the sum over the tower of KK modes may partially
compensate in processes of relevance at high-energy colliders. Here we consider
the inclusive differential and total cross sections for e^- e^- --> W^- W^- J,
where J represents a sum over KK modes. We show that allowed parameter choices
exist for which this process may be accessible to a TeV-scale electron
collider.Comment: 11 pages LaTeX, 3 eps figures (references added
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