55 research outputs found
Relativistic Description of Exclusive Semileptonic Decays of Heavy Mesons
Using quasipotential approach, we have studied exclusive semileptonic decays
of heavy mesons with the account of relativistic effects. Due to more complete
relativistic description of the quark more precise expressions for
semileptonic form factors are obtained. Various differential distributions in
exclusive semileptonic decays of heavy mesons are calculated. It is argued that
consistent account of relativistic effects and HQET motivated choice of the
parameters of quark-antiquark potential allow to get reliable value for the
ratio in the decay as well as the
ratio~. All calculated branching
ratios are in accord with available experimental data.Comment: 18 pages, LATEX, 2 figures inclosed + 4 Postscript figure
Relativistically invariant analysis of polarization effects in exclusive deuteron electrodisintegration process
A general formalism for the calculation of the differential cross section and
polarization observables, for the process of deuteron electrodisintegration, is
developed in the framework of relativistic impulse approximation. A detailed
analysis of the general structure of the differential cross section and
polarization observables for the reaction is derived, using
the formalism of the structure functions. The obtained expressions have a
general nature and they hold in the one--photon--exchange mechanism, assuming
P--invariance of the hadron electromagnetic interaction. The model of
relativistic impulse approximation is introduced and the final state
interaction is taken into account by means of the unitarization of the helicity
amplitudes. A detailed description of the unitarization procedure is also
presented.
Using different parametrizations of the deuteron wave functions, the
following polarization observables are calculated in the kinematical region of
quasi--elastic deuteron electrodisintegration: the asymmetry for the scattering
of longitudinally polarized electrons on a polarized deuteron target, the
proton and neutron polarizations (for longitudinally polarized electron beam or
vector--polarized deuteron target). The sensitivity to the neutron electric
form factor is also thorougly investigated.
The predictions of the model are compared with the results of recent
polarization measurements and a good agreement with the existing experimental
data has been obtained.Comment: 90 pages, 17 figure
Ward Identities, B-> \rho Form Factors and |V_ub|
The exclusive FCNC beauty semileptonic decay B-> \rho is studied using Ward
identities in a general vector meson dominance framework, predicting vector
meson couplings involved. The long distance contributions are discussed which
results to obtain form factors and |V_ub|. A detailed comparison is given with
other approaches.Comment: 30 pages+four postscript figures, an Appendix adde
Inclusive pion double charge exchange on Oxygen(16) at 0.6-1.1 GeV
The inclusive pion double charge exchange (DCX) on oxygen nuclei has been
measured in the region where additional pion production is kinematically
forbidden. The experiment was performed at ITEP PS at incident pi- kinetic
energies T_0= 0.59, 0.75 and 1.1 GeV. The integrated forward differential cross
section was found to decrease with energy slowly. At 1.1 GeV it exceeds the
theoretical prediction within the conventional sequential single charge
exchange mechanism with a neutral pion in the intermediate state (Glauber
elastic rescattering) by about half an order of magnitude. The sequential
mechanism with two pions in the intermediate state (Glauber inelastic
rescatterings), which was proposed recently, seems to be able to explain the
observed slow energy dependence and allows to predict the DCX cross section for
higher energies.Comment: 27 pages, 13 figures. Minor corrections, one figure added. Accepted
in NP
New measurement of the rare decay with CMD-2
A new measurement of the rare decay \phi \to \eta' \gamma performed with the
CMD-2 detector at Novosibirsk is described. Of the data sample corresponding to
the integrated luminosity of 14.5 pb^{-1}, twenty one events have been selected
in the mode \eta'\to\pi^+\pi^-\eta, \eta\to\gamma\gamma. The following
branching ratio was obtained: B(\phi \to \eta' \gamma) = (8.2^{+2.1}_{-1.9} \pm
1.1) 10^{-5}.Comment: 12 pages, 4 figures, LaTe
The present and future of QCD
This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming decades
Partially replacing cyclophosphamide with bendamustine in combination with cyclosporine A improves survival and reduces xenogeneic graft-versus-host-disease
Introduction: The use of allogeneic hematopoietic cell transplantation (allo-HCT) for treating hematological disorders is increasing, but the development of graft-versus-host disease (GvHD) remains a major cause of morbidity and mortality. The use of post-transplant cyclophosphamide (CY) has significantly improved outcomes following allo-HCT, but complications of viral reactivation due to delayed immune reconstitution or relapse remain. Other laboratories are evaluating the potential benefit of lowering the dose of CY given post-transplant, whereas our laboratory has been focusing on whether partially replacing CY with another DNA alkylating agent, bendamustine (BEN) may be advantageous in improving outcomes with allo-HCT. Methods: Here, we utilized a xenogeneic GvHD (xGvHD) model in which immunodeficient NSG mice are infused with human peripheral blood mononuclear cells (PBMCs). Results: We show that a lower dose of CY (25 mg/kg) given on days +3 and +4 or CY (75 mg/kg) given on only day +3 post-PBMC infusion is not sufficient for improving survival from xGvHD, but can be improved with the addition of BEN (15 mg/kg) on day +4 to day +3 CY (75 mg/kg). CY/BEN treated mice when combined with cyclosporine A (CSA) (10mg/kg daily from days +5 to +18 and thrice weekly thereafter), had improved outcomes over CY/CY +CSA treated mice. Infiltration of GvHD target organs was reduced in both CY/CY and CY/BEN treatment groups versus those receiving no treatment. CY/CY +CSA mice exhibited more severe xGvHD at day 10, marked by decreased serum albumin and increased intestinal permeability. CY/BEN treated mice had reductions in naïve, effector memory and Th17 polarized T cells. RNAseq analysis of splenocytes isolated from CY/CY and CY/BEN treated animals revealed increased gene set enrichment in multiple KEGG pathways related to cell migration, proliferation/differentiation, and inflammatory pathways, among others with CY/BEN treatment. Conclusion: Together, we illustrate that the use of CY/BEN is safe and shows similar control of xGvHD to CY/CY, but when combined with CSA, survival with CY/BEN is significantly prolonged compared to CY/CY. Copyright © 2023 Gilman, Cracchiolo, Matiatos, Davini, Simpson and Katsanis.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
The development of a GIS methodology to assess the potential for water resource contamination due to new development in the 2012 Olympic Park site, London
The Initial Screening Tool (IST) has been developed to enable Planners to assess the potential risk to ground and surface water due to remobilisation of contaminants by new developments. The IST is a custom built GIS application that improves upon previous screening tools developed by the British Geological Survey (BGS) through the inclusion of 3-D geological data and an enhanced scoring methodology. The key new feature of the IST is the ability to track individual pollutant linkages, from a source of contamination, along multiple possible Pathways to potentially susceptible Receptors. A rule based approach allows the methodology to be easily updated, and as a result the IST has a role in scenario planning. The application provides output in the form of an automatically generated report, in which details of the potential pollutant linkages identified are presented. The initial research area selected was the Olympic Park site, London
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