280 research outputs found
Power counting and effective field theory for charmonium
We hypothesize that the correct power counting for charmonia is in the
parameter Lambda_QCD/m_c, but is not based purely on dimensional analysis (as
is HQET). This power counting leads to predictions which differ from those
resulting from the usual velocity power counting rules of NRQCD. In particular,
we show that while Lambda_QCD/m_c power counting preserves the empirically
verified predictions of spin symmetry in decays, it also leads to new
predictions which include: A hierarchy between spin singlet and triplet octet
matrix elements in the J/psi system. A quenching of the net polarization in
production at large transverse momentum. No end point enhancement in radiative
decays. We discuss explicit tests which can differentiate between the
traditional and new theories of NRQCD.Comment: 18 pages, 1 figure Replaced plot of the psi polarization parameter
alpha as a function of transverse momentum. Alpha is now closer to zero for
large transverse moment
Propriétés des critères des lignes limites de dégagement chez les arbres Nord Américains
A Measurement of Psi(2S) Resonance Parameters
Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been
measured in the vicinity of the Psi(2S) resonance using the BESII detector
operated at the BEPC. The Psi(2S) total width; partial widths to hadrons,
pi+pi- J/Psi, muons; and corresponding branching fractions have been determined
to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)=
(2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)=
(97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%,
respectively.Comment: 8 pages, 6 figure
Shell occupation by the hermit crab Dardanus insignis (Decapoda, Diogenidae) from the north Coast of São Paulo state, Brazil
Measurements of Cabibbo Suppressed Hadronic Decay Fractions of Charmed D0 and D+ Mesons
Using data collected with the BESII detector at storage ring
Beijing Electron Positron Collider, the measurements of relative branching
fractions for seven Cabibbo suppressed hadronic weak decays ,
, and , , and are presented.Comment: 11 pages, 5 figure
Shell occupation by the South Atlantic endemic hermit crab Loxopagurus loxochelis (Moreira, 1901) (Anomura: Diogenidae)
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Relations between Financing and Output in the Not-for-Profit Hospital
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68639/2/10.1177_107755878804500204.pd
Air-exposure behavior: a restricted or a common conduct among intertidal hermit crabs?
A new behavior related to shell care was recently reported for the intertidal hermit crab Clibanarius erythropus (Latreille, 1818) in the Gulf of Cádiz (southwestern Europe). It also has been observed in other species of the diogenid genera Clibanarius Dana, 1952, and Calcinus Dana, 1951, however, it has not been described as an active behavior. In the present study, intertidal hermit crabs from different species and localities were sampled to assess if air-exposure is a shell cleaning behavior restricted to some species of intertidal hermit crabs or if it is a more generalized behavior among species inhabiting intertidal habitats. The results revealed that air-exposure is an active behavior in species of Clibanarius and Calcinus, since we observed it also in Clibanarius albidigitus Nobili, 1901, and Calcinus obscurus Stimpson, 1859, from the Pacific coast of Costa Rica, although not in other intertidal species studied by us. We found interspecific differences in tolerance to physical stress of emerged hermit crabs. This air-exposure tolerance can be interpreted as a physiological adaptation to desiccation stress and is also related to the shell type they inhabit. Also, we provide additional features and details of the air-exposure behavior, combining observations of the first description in 2015 with our new field observations.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí
Arguments against the requirement of a biological license application for human pancreatic islets: The position statement of the islets for us collaborative presented during the fda advisory committee meeting
The Food and Drug Administration (FDA) has been regulating human islets for allo-transplantation as a biologic drug in the US. Consequently, the requirement of a biological license application (BLA) approval before clinical use of islet transplantation as a standard of care procedure has stalled the development of the field for the last 20 years. Herein, we provide our commentary to the multiple FDA’s position papers and guidance for industry arguing that BLA requirement has been inappropriately applied to allogeneic islets, which was delivered to the FDA Cellular, Tissue and Gene Therapies Advisory Committee on 15 April 2021. We provided evidence that BLA requirement and drug related regulations are inadequate in reassuring islet product quality and potency as well as patient safety and clinical outcomes. As leaders in the field of transplantation and endocrinology under the “Islets for US Collaborative” designation, we examined the current regulatory status of islet transplantation in the US and identified several anticipated negative consequences of the BLA approval. In our commentary we also offer an alternative pathway for islet transplantation under the regulatory framework for organ transplantation, which would address deficiencies of in current system
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