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.
Measurement of Γee(J/ψ) with KEDR detector Anashin, V. V; Aulchenko, V. M; Baldin, E. M ...
The journal of high energy physics,
05/2018, Letnik:
2018, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A
bstract
The product of the electronic width of the
J/ψ
meson and the branching fractions of its decay to hadrons and electrons has been measured using the KEDR detector at the VEPP-4M
e
+
e
−
...collider. The obtained values are
Γ
e
e
J
/
ψ
=
5.550
±
0.056
±
0.089
keV
,
Γ
e
e
J
/
ψ
·
ℬ
hadrons
J
/
ψ
=
4.884
±
0.048
±
0.078
keV
,
Γ
e
e
J
/
ψ
·
ℬ
e
e
J
/
ψ
=
0.3331
±
0.0066
±
0.0040
keV
.
The uncertainties shown are statistical and systematic, respectively. Using the result presented and the world-average value of the electronic branching fraction, one obtains the total width of the
J/ψ
meson:
Γ
=
92.94
±
1.83
keV
.
These results are consistent with the previous experiments.
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.
VEPP-4 is a multipurpose storage ring facility at Budker Institute of Nuclear Physics (Novosibirsk, Russia) with several research programs including high energy physics in colliding beam mode, ...nuclear physics, synchrotron radiation, accelerator physics study, etc. The paper discusses VEPP-4 activities relating to generation and application of synchrotron radiation not only for SR user community but for beam diagnostics in storage ring as well.
In Novosibirsk, the Synchrotron Radiation Facility Siberian Circular Photon Source (SRF SKIF) 4+ generation synchrotron radiation source is currently under construction. Its specific feature is a low ...emittance at a high beam current. Collective effects in the dynamics of an intense beam may lead to various instabilities and, correspondingly, to worsen the quality of a beam or its complete loss. To suppress the undesirable effects, it is necessary to analyze the interaction of a beam with different vacuum chamber elements to minimize their impedances. This paper presents the calculation of longitudinal and transversal impedances for the main elements of the vacuum chamber of the SKIF storage ring, such as the fundamental harmonic resonator, flange connection, compensator, beam position monitor, and pumping port. The total coherent losses, kick-factor, and total effective impedance are calculated, and the contributions from each type of elements to the total characteristics are estimated.
The construction of an electron–positron collider of the megascience class, referred to as the Super Charm–Tau Factory, is envisaged at the Budker Institute of Nuclear Physics (Novosibirsk). The beam ...energy will vary between 1 and 2.5 GeV, and the peak luminosity of the machine will reach 10
35
cm
–2
s
–1
owing to the Crab-Waist collision scheme and to high beam currents (up to 2 A). The project provides for a longitudinal polarization of the electron beam in the collision region. The physics agenda includes in-depth studies of the
c
-quark and tau-lepton properties and a search for beyond-SM physics.
Tungsten samples irradiated by an electron beam on a BETA generator are studied to model plasma heat loads in a vacuum chamber of a fusion reactor. The residual stresses in the irradiated samples, ...including those fabricated according to ITER specifications, are measured via X-ray diffraction.
A method proposed to preserve the electron beam polarization at the VEPP-4M collider during acceleration with crossing the integer (imperfection) spin resonance at energyE=1763MeVhas been ...successfully applied. It is based on full decompensation of the0.6×3.3Tesla×meterintegral of the KEDR detector longitudinal magnetic field due to the antisolenoid being “switched off.”
Small-angle scattering of synchrotron radiation is used to study thermal transformations of ε-form hexanitrohexaazaisowurtzitane crystals subjected to electron beam processing. It is shown the ...destruction of crystals treated with an electron beam begins far below the point of the polymorphic transition. A conclusion is drawn about the effect products of radiolysis have on the destruction of the crystals. A mechanism of crystal destruction is proposed.
In this paper, we describe the current state of development of a prototype detector for the study of fast processes (DIMEX) based on a silicon microstrip sensor. The silicon microstrip sensor is made ...of
n
-type silicon with
p
-type implants in the form of strips. Aluminum contacts with microwelding pads at the ends are applied to the strips along the entire length. The signals from the strips are read using a DMXS6A integrated circuit specially designed for this project, which contains six recording electronic channels with a dark-current compensation circuit at the input, four integrators, 32 analog memory cells, and an analog shift register. Each sensor strip is connected to the guard ring through a 400-Ω resistor and to the recording-channel input through a 100-kΩ resistor. This resistive divider at the input of the recording channel makes it possible to adapt the dynamic range of the recording microcircuit integrator to the full range of photon-flux changes in synchrotron-radiation output channel no. 8 of the VEPP-4M storage ring equipped with a nine-pole wiggler with a field of 1.95 T as the source of synchrotron radiation. Measurements of the dynamic range of the DIMEX-Si prototype show that the maximal flux that can be recorded in the linear mode exceeds 10
5
photons/channel from each electron bunch in the storage ring. The ability of the detector to detect signals from bunches following after 55 ns in the multi-bunch mode, which simulates the operation of the 4+-generation synchrotron-radiation source Siberian Circular Photon Source (SKIF) under construction in the Novosibirsk region, on which such a detector is planned to be used, is also demonstrated.
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