The ηππ and ωω systems produced in the
π
−
Be interactions with 37GeV/
c
π
− beam have been studied at the VES spectrometer. For the unnatural-parity exchange, the isoscalar channels demonstrate ...similar structures in
ηπ
−
π
+ and ωω final states, while the amplitudes with
I = 1 have the same behaviour for
ηπ
+
π
−
π
0. The
I = 0
J
PC
= 2
++ amplitudes show the signal of
f
2(1565) meson which decays to
a
2(1320)
π
− and ωω. The
f
2(1920) meson is observed in ωω. In the
I = 0
J
PC
= 4
++ intensities there are signals from
f
4(2050) and
f
4(2330) mesons.
The
I = 1
J
PC
= 3
−− waves demonstrate the presence of
p
3(1690) meson in
a
2(1320)
π and
pη decay modes. 3
−− waves at higher masses have complex behaviour and can be modelled by the further 3
−− resonances.
Natural parity resonances in ηπ+π Amelin, D; Berdnikov, E; Bityukov, S ...
Nuclear physics. A,
3/2000, Letnik:
668, Številka:
1
Journal Article
Recenzirano
Results of a partial wave analysis of the
ηπ
+
π
− final state are presented using 4.2×10
4 events with |
t|<0.2 GeV
2, collected at the VES setup; the reaction is
π
−
p→
π
−
π
+
ηn from a beryllium ...target. The data reveal resonant structures, which are identified by phase motion as well as peaks in intensities of partial waves. The
f
2(1565) meson, also called the
AX meson, is observed in decays to
a
2(1302)
π
L=1
. The parameters obtained from a fit with a Breit–Wigner amplitude are
M=1550±20 MeV with
Γ=130±40 MeV. The higher mass
f
2 resonances are also discussed. For
J
P
=3
−, the well known
ρ
3(1690) is seen in decays to both
a
2(1320)
π and
ρη channels. The complex behaviour of 3
−− amplitudes at higher masses is described best by introducing two additional resonant poles near 2.14 and 2.30 GeV. There is evidence for an
f
4(2300) meson, decaying dominantly to
f
2
η
L=3
.
Electrostatic potential profiles were calculated for σ70-specific phage T4 promoters and four consensus-like synthetic promoters. Promoters could be classified according to the presence of specific ...elements of the electrostatic profile in the farther upstream region (−60 to −100). A correlation was found between the kind of such specific element and the functional behavior of the promoter. A general scheme is proposed whereby the promoter activity is regulated through electrostatic interactions between the upstream region of promoter DNA and the RNA polymerase α-subunit.
Electrostatic profiles for sigma70-specific promoters of T4 bacteriophage and four consensus-like synthetic promoters have been calculated. It was shown that the promoters can be classified according ...to the presence of some specific electrostatic elements located in the far upstream region of their DNAs. A correlation between the electrostatic elements specific for promoters and their functional behaviour was established. A general scheme of promotor activity regulation through electrostatic interactions between the upstream region of promoter DNA and the RNA-polymerase a-subunit was suggested.
This paper presents the design of the LHCb trigger and its performance on data taken at the LHC in 2011. A principal goal of LHCb is to perform flavour physics measurements, and the trigger is ...designed to distinguish charm and beauty decays from the light quark background. Using a combination of lepton identification and measurements of the particles' transverse momenta the trigger selects particles originating from charm and beauty hadrons, which typically fly a finite distance before decaying. The trigger reduces the roughly 11\,MHz of bunch-bunch crossings that contain at least one inelastic \(pp\) interaction to 3\,kHz. This reduction takes place in two stages; the first stage is implemented in hardware and the second stage is a software application that runs on a large computer farm. A data-driven method is used to evaluate the performance of the trigger on several charm and beauty decay modes.
PDF
