A
bstract
The cross section of the process
e
+
e
−
→
π
+
π
−
has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000
e
+
e
−
collider VEPP-2000 in the energy region 525
...<
s
<
883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb
−
1
. The systematic uncertainty of the cross section determination is 0.8% at
s
>
0
.
600 GeV. The
ρ
meson parameters are obtained as
m
ρ
= 775
.
3 ± 0
.
5 ± 0
.
6 MeV, Γ
ρ
= 145
.
6 ± 0
.
6 ± 0
.
8 MeV,
B
ρ
→
e
+
e−
×
B
ρ
→
π
+
π−
= (4
.
89 ± 0
.
02 ± 0
.
04) × 10
−
5
, and the parameters of the
e
+
e
−
→
ω
→
π
+
π
−
process, suppressed by
G
-parity, as
B
ω
→
e
+
e−
×
B
ω
→
π
+
π−
= (1
.
32 ± 0
.
06 ± 0
.
02) × 10
−
6
and and
ϕ
ρω
= 110
.
7 ± 1
.
5 ± 1
.
0 degrees.
The beam energy measurement system for the VEPP-2000 electron-positron collider is described. The method of Compton backscattering of CO laser photons on the electron beam is used. The relative ...systematic uncertainty of the beam energy determination is estimated as 610 super(-5). It was obtained through comparison of the results of the beam energy measurements using the Compton backscattering and resonance depolarization methods.
Results are presented from measuring the
cross section and effective neutron timelike form factor. Data are collected in 2020–2021 at the VEPP-2000
collider in the 1891 to 2007 MeV center-of-mass ...range of energies. The general purpose nonmagnetic SND detector is used to detect neutron–antineutron events. The time-of-flight approach is used to select
events. The measured cross section is 0.4–0.6 nbn. The neutron form factor in the investigated range of energies varies from 0.3 to 0.2.
Status and perspectives of the VEPP-2000 Shatunov, P. Yu; Berkaev, D. E.; Zharinov, Yu. M. ...
Physics of particles and nuclei letters,
12/2016, Letnik:
13, Številka:
7
Journal Article
Recenzirano
The electron-positron collider VEPP-2000 operates at BINP from 2010 year. The application of round colliding beams concept along with the accurate orbit and lattice correction yielded the high peak ...luminosity of 1.2 × 10
31
cm
−2
s
−1
at 500MeV. The peak luminosity limited only by beam-beam effects, while average luminosity–by present lack of positrons in whole energy range of 160–1000 MeV. To perform high luminosity at high energies the top-up injection is needed. At present new electron and positron injection complex at BINP is commissioned and ready to feed VEPP-2000 collider with intensive beams with energy of 450MeV.
In this Letter we report an observation of interference effects in Compton scattering in the experiment held on the VEPP-2000 collider. Infrared laser radiation was scattered head-on the 990 MeV ...electrons inside the dipole magnet, where an electron orbit radius is about 140 cm. It was observed that the energy spectrum of backscattered photons, measured by a HPGe detector, differs from that defined by the Klein-Nishina cross section and scattering kinematics of free electrons. The explanation of the effect, proposed in terms of classical electrodynamics, is in agreement with QED calculations.
VEPP-2000 is the only electron–positron collider with round beams. This factor enables one to increase the beam–beam effect limit. During the 2018–2019 season, the experimental program was focused on ...the energy range of 550–990 MeV per beam. Data accumulation was performed using CMD-3 and SND detectors. The measured luminosity integral proved to have a record value of 68 pb
–1
per detector. After connecting to the BINP injection complex in 2016, the luminosity of VEPP-2000 is limited by the beam–beam effects in the entire energy range.
Recent Progress in the VEPP-2000 Collider Rastigeev, S. A.; Aktershev, Yu. S.; Bedarev, E. V. ...
Physics of particles and nuclei letters,
08/2023, Letnik:
20, Številka:
4
Journal Article
Recenzirano
The VEPP-2000 is an electron–positron collider with round beams built and operating at the Budker Institute of Nuclear Physics (BINP). The collider luminosity was increased twofold last year. The ...integrated luminosity accumulated over the last year has exceeded 0.3 fb
–1
, which almost doubled the total data collected since the collider operation began. The short description of the VEPP-2000 complex, current status, and the results are presented in this work.
Nuclotron based Ion Collider fAcility (NICA) project is in progress at the Joint Institute for Nuclear Research and will start experiments with heavy ions. In the context of the NICA hadronic physics ...programme double polarized
-,
- and
-collisions even at lower energies of
GeV, which will be accessible already at the initial stage of experiments,are essential tools for precise studying the spin dependence of the nucleon–nucleon strong interactions, in both elastic and deep-inelastic regimes. A special interest is interaction in few baryon systems at double strangeness, charm and beauty thresholds.For instance, polarized large-angle elastic
and
scattering near the charm threshold allows one to get an access to properties of possible exotic multiquark states and their relation to the states recently observed at LHCb.Large angle scattering of protons and deuterons on the deuteron contains unique information on the short-range structure of the deuteron, its nonnucleonic degrees of freedom and also on color transparency phenomenon. Furthermore, double polarized proton–deuteron scattering offer a possibility to test the Standard Model through the search for time-invariance (or CP-invariance under CPT symmetry) violation and parity-violation in single-polarized scattering. This paper contains suggestions for experiments with usage of the Spin Physics Detector (SPD) and discusses perspectives of the first stage of the SPD Programme. This includes experiments with nonpolarized beams too as well as collisions like
12
С–
12
С and
40
Сa–
40
Ca.
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