2,511 research outputs found
Phylogenetic relationships within Orobanche and Phelipanche (Orobanchaceae) from Central Europe, focused on problematic aggregates, taxonomy, and host ranges
Holoparasitic genera within the family Orobanchaceae are characterized by greatly reduced vegetative organs;
therefore, molecular analysis has proved to be a useful tool in solving taxonomic problems in this family. For
this purpose, we studied all species of the genera
Orobanche
and
Phelipanche
occurring in Central Europe,
specifically in Poland, the Czech Republic, Slovakia, and Austria, supplemented by samples mainly from Spain,
France, Germany, and Ukraine. They were investigated using nuclear sequences (ITS region) and a plastid
trnL-
trnF
region. The aim of this study was to examine phylogenetic relationships within
Orobanche
and
Phelipanche
from Central Europe; we focused on problematic species and aggregates, recent taxonomic changes in these
(rank and secondary ranks), and host ranges. The most interesting results concern the exlusion of
O. mayeri
from
O. alsatica
aggr. Additionally, following the rules of traditional taxonomy, the correct names and types of
some secondary ranks are given and, as a result of this, a new combination below the
Phelipanche
genus is made
(
P
.
sect.
Trionychon
). The host ranges of the investigated species in Central Europe include 102 species from 12
families, most often from Asteraceae. For this purpose, ca. 400 localities were examined in the field. Moreover,
data acquired from the literature and European and Asian herbaria were use
Observation of a charged charmoniumlike structure in at GeV
We study the process at a
center-of-mass energy of 4.26GeV using a 827pb data sample obtained with
the BESIII detector at the Beijing Electron Positron Collider. Based on a
partial reconstruction technique, the Born cross section is measured to be
pb. We observe a structure near the
threshold in the recoil mass spectrum, which we denote as the
. The measured mass and width of the structure are
MeV/c and MeV, respectively. Its
production ratio is determined to be . The first uncertainties
are statistical and the second are systematic.Comment: 7 pages, 4 figures, 1 table; version accepted to be published in PR
Search for the Lepton Flavor Violation Process at BESIII
We search for the lepton-flavor-violating decay of the into an
electron and a muon using events
collected with the BESIII detector at the BEPCII collider. Four candidate
events are found in the signal region, consistent with background expectations.
An upper limit on the branching fraction of (90% C.L.) is obtained
Measurement of azimuthal asymmetries in inclusive charged dipion production in annihilations at = 3.65 GeV
We present a measurement of the azimuthal asymmetries of two charged pions in
the inclusive process based on a data set of 62
at the center-of-mass energy GeV collected with
the BESIII detector. These asymmetries can be attributed to the Collins
fragmentation function. We observe a nonzero asymmetry, which increases with
increasing pion momentum. As our energy scale is close to that of the existing
semi-inclusive deep inelastic scattering experimental data, the measured
asymmetries are important inputs for the global analysis of extracting the
quark transversity distribution inside the nucleon and are valuable to explore
the energy evolution of the spin-dependent fragmentation function.Comment: 7 pages, 5 figure
Observation of at BESIII
Using events collected with the BESIII detector
at the BEPCII storage rings, we observe for the first time the process
,
with a significance of ( including systematic
uncertainties). The product branching fraction of is measured to be
, where the first error is statistical and the
second is systematic. This measurement provides information on the
production near threshold coupling to and improves the understanding
of the dynamics of decays to four body processes.Comment: 8 pages, 7 figure
Measurement of the cross section and search for at center-of-mass energies between 3.810 and 4.600~GeV
Using data samples collected with the BESIII detector operating at the BEPCII
collider at center-of-mass energies from 3.810 to 4.600 GeV, we perform a study
of and . Statistically significant
signals of are observed at = 4.190,
4.210, 4.220, 4.230, 4.245, 4.260, 4.360 and 4.420 GeV, while no signals of
are observed. The measured energy-dependent
Born cross section for shows an enhancement around
4.2~GeV. The measurement is compatible with an earlier measurement by Belle,
but with a significantly improved precision
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