A
bstract
We present the study of the decay
J/ψ
→
ρπ
. The results are based on of 5.2 million
J/ψ
events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured ...to be
B
(
J/ψ
→
ρπ
) = (2
.
072 ± 0
.
017 ± 0
.
062) ∙ 10
−
2
and
B
(
J/ψ
→
π
+
π
−
π
0
) = (1
.
878 ± 0
.
013 ± 0
.
051) ∙ 10
−
2
, where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.
The future
e
+
e
−
Super Charm-Tau Factory (SCTF) to be built at Novosibirsk will cover an energy range of 2 – 7 GeV. The projected record luminosity of 10
35
cm
−2
s
−1
and the longitudinal ...polarization of the electrons will enable a wide range of standard model precision tests and options for the discovery of flavor violating decays beyond the standard model. A 4
π
detector with excellent particle identification (PID) is required with challenging
μ
/
π
-separation in the range 0.2 – 1.2 GeV/c. This talk focuses on two new concepts and the first tests of novel Cherenkov detectors for SCTF, a focusing aerogel RICH (FARICH) and a focusing DIRC (fDIRC). Both require single-photon detection with good coordinate and timing resolution. The prototyping for both versions already started at BINP and Giessen. The tests include various photon detectors (MCP-PMT, SIPM, MPPC). The first results using cosmic muons at the Giessen Cosmic Station are presented.
Abstract
In this article a short overview of current micro-pattern gaseous detectors development and applications at Budker Institute of Nuclear Physics is presented. The triple-GEM detector for the ...Laser Polarimeter facility and the end-cap discs for the upgrade of the CMD-3 detector are considered in more details.
The electronic width of the
J
/
ψ
meson and its product by the branching fractions of
J
/
ψ
meson decay to hadrons and electrons measured with the KEDR detector at the VEPP-4M
e
+
e
−
collider have ...been reported in ref. 1.
Test Beam facility is an experimental facility of the VEPP-4M collider uses Brems-strahlung gamma-rays from the movable beam scraper inserted in the halo of the circulating electron beam for test ...experiments with HEP detector components. Measurements taken at this installation require high-resolution low-mass tracking detectors to precisely determine particle trajectories. The high-resolution GEM-based tracking detector developed for this facility is described in this paper.
In this paper we investigated Cherenkov radiation component influence on the time of charged particle detection in LYSO(Ce) crystals. Description of the experiment setup and Monte Carlo simulation ...scheme are given. The scintillation and Cherenkov radiation processes in LYSO(Ce) crystal were simulated and studied experimentally with electron beam at Budker Institute of Nuclear Physics beam test facilities. The results of the measurements and simulation are presented. The effect of particle detection time shift due to Cherenkov radiation was obtained. It amounts of several tens of picoseconds for LYSO(Ce) crystal bar (it has dimensions of 3×4×50 mm3). Beam test results are in good agreement with calculations.
Using the 1.32
pb
-
1
statistics collected at the
J
/
ψ
peak with the KEDR detector at the VEPP-4M
e
+
e
-
collider, we measured the branching fractions of
J
/
ψ
meson decays to the final states 2(
π
...+
π
-
)
π
0
,
K
+
K
-
π
+
π
-
π
0
, 2(
π
+
π
-
)
and
K
+
K
-
π
+
π
-
. The results obtained for the decays
J
/
ψ
→
2(
π
+
π
-
)
π
0
,
J
/
ψ
→
K
+
K
-
π
+
π
-
π
0
contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.
To accomplish the physical program of studies at the planned Super Charm-Tau Factory electron-positron collider, a high-precision particle identification system is required. A FARICH–ring-imaging ...Cherenkov detector based on focusing aerogel and an array of silicon photomultipliers is proposed. The paper describes a reconstruction algorithm developed for such a detector. The algorithm was tested on simulated pion events with different photodetector noise levels. For dark count rates up to 10
5
Hz/mm
2
, the factor
uncertainty is shown to be less than 5 × 10
–4
(1 × 10
–3
) for pions with momenta of 0.6–1.5 GeV/c and incident angles of 0°–10° (0°–45°) with respect to the normal to the detector plane.
Abstract
Using the 1.32
$$\hbox {pb}^{-1}$$
pb
-
1
statistics collected at the
$$J/\psi $$
J
/
ψ
peak with the KEDR detector at the VEPP-4M
$$e^{+}e^{-\, }$$
e
+
e
-
collider, we measured the ...branching fractions of
$$J/\psi $$
J
/
ψ
meson decays to the final states 2(
$$\pi ^{+}\pi ^{-})\pi ^{0}$$
π
+
π
-
)
π
0
,
$$K^{+}K^{-}\pi ^{+}\pi ^{-}\pi ^{0}$$
K
+
K
-
π
+
π
-
π
0
, 2(
$$\pi ^{+}\pi ^{-})$$
π
+
π
-
)
and
$$K^{+}K^{-}\pi ^{+}\pi ^{-}$$
K
+
K
-
π
+
π
-
. The results obtained for the decays
$$J/\psi \rightarrow $$
J
/
ψ
→
2(
$$\pi ^{+}\pi ^{-})\pi ^{0}$$
π
+
π
-
)
π
0
,
$$J/\psi \rightarrow K^{+}K^{-}\pi ^{+}\pi ^{-}\pi ^{0}$$
J
/
ψ
→
K
+
K
-
π
+
π
-
π
0
contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Budker Institute of Nuclear Physics is actively evolving the Super Charm-Tau Factory project. A drift chamber with a small hexagonal cell was proposed for this collider. For experimental measurements ...of a spatial resolution, a drift chamber small prototype consisting of seven cells has been developed. The experiments have been carried out in He/C3H8 (60/40) and He/C2H6 (50/50) gas mixtures at different gas gains using cosmic particles. For this purpose, a calibration procedure for R(t, α) has been developed and fine-tuned, taking into account small prototype features and an angular dependence of isochrones at the edge of the cells. As a result, the average spatial resolutions are less than 100μm for gas gains greater than 5⋅104.
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