# ND experiment

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**Neutral Detector** (**ND**) is a [detector](/source/Detector) for [particle physics](/source/Particle_physics) [experiments](/source/Experiment) created by the team of physicists in the [Budker Institute of Nuclear Physics](/source/Budker_Institute_of_Nuclear_Physics), [Novosibirsk](/source/Novosibirsk), [Russia](/source/Russia). Experiments with the **ND** were conducted from 1982 to 1987 at the e+e− [storage ring](/source/Storage_ring) VEPP-2M in the [energy](/source/Energy) range 2*E* = 0.5 GeV.[1]

## Physics

At the beginning of 80s the leading [cross sections](/source/Scattering_cross-section) of the [electron](/source/Electron)-[positron](/source/Positron) [annihilation](/source/Annihilation) in the final states with [charged particles](/source/Charged_particle) were measured in the energy range 2E=0.5-1.4 GeV. Processes with the [neutral particles](/source/Neutral_particle) in the final state were less studied. To investigate the [radiative decays](/source/Particle_decay) of the \rho^0, \omega, and \phi [mesons](/source/Meson) and other processes involving [photons](/source/Photon), \pi^0, and \eta [mesons](/source/Meson) the **ND** [2] was constructed. Its distinguishing features are defined by the specially designed [electromagnetic calorimeter](/source/Calorimeter_(particle_physics)) based on [NaI](/source/NaI)(Tl) [scintillation counters](/source/Scintillation_counter).

**List of published analyses** [1]

- [Radiative decays](/source/Particle_decay)

- e^+e^- \to \rho, \omega, \phi \to \pi^0 \gamma, \eta \gamma [3][4]
- \phi \to \eta^\prime \gamma [5]

- Rare decays of the \rho^0, \omega, and \phi mesons

- \omega, \phi \to \pi^0 e^+e^- [6]
- \phi \to \pi^+ \pi^- [7]

- Search for rare decays

- \rho \to \pi^+ \pi^- \pi^0 [8]
- \omega, \phi \to \pi^0 \pi^0 \gamma [3][5]
- \phi \to \pi^0 \eta \gamma [9]
- light scalars a_0(980) and f_0(975) in \phi-meson radiative decays [5]

- Non-[resonant](/source/Resonance_(particle_physics)) electron-positron [annihilation](/source/Annihilation) into [hadrons](/source/Hadron)

- e^+e^- \to \omega \pi^0 [10]
- e^+e^- \to \pi^+ \pi^- \pi^0 ,~~ \pi^+ \pi^- \eta [11][12]
- e^+e^- \to \pi^+ \pi^- \pi^+ \pi^-,~~ \pi^+ \pi^- \pi^0 \pi^0 [13]

- Test of [QED](/source/Quantum_electrodynamics) processes [14][15]

- e^+e^- \to \gamma \gamma \gamma \gamma
- e^+e^- \to e^+e^- \gamma \gamma
- e^+e^- \to e^+e^- e^+e^-
- e^+e^- \to e^+e^- \gamma (virtual [Compton scattering](/source/Compton_scattering)) [16]

- Analyses of other processes - Measurement of the ω-meson parameters [17] - Upper limits on electron [width](/source/Resonance_(particle_physics)) of [scalar](/source/Scalar_meson) and [tensor](/source/Tensor) mesons f_0(975), f_2(1270), f_0(1300), a_0(980), and a_2(1320) [18] - \phi \to \pi^+ \pi^- \pi^0,~~ K^0_S K^0_L [19] - Search for - e^+e^- \to \pi^0 \pi^0 \gamma [20] - K^0_S \to \gamma \gamma [21] - e^+e^- \to C(1480) \to \phi \pi^0 [22]

## Detector

Based on goals of the physics program the **ND** consist of

**Electromagnetic calorimeter**

- 168 rectangular [NaI](/source/NaI)(Tl) scintillation counters
- total mass of [NaI](/source/NaI)(Tl) is 2.6 t
- [solid angle](/source/Solid_angle) coverage is 65% of 4π sr
- minimum thickness is 32 cm or 12 radiation length
- energy resolution for photons is σ/E = 4% / √E

**Charged particle coordinate system**

- 3 layers of coaxial cylindrical 2-d wire [proportional chambers](/source/Wire_chamber) in the center of the detector
- solid angle coverage is 80% of 4π sr
- angular resolution is 0.5° in the azimuthal and 1.5° in the polar direction
- surrounded by the 5-mm thick plastic scintillation counter for trigger

**Flat (shower) coordinate 2-d wire proportional chambers**

- 2 layers of flat 2-d wire proportional chambers.
- angular resolution is 2° in the azimuthal and 3.5° in the polar direction for 0.5 GeV photons

**Iron absorber & anti-coincidence counters**

- The electromagnetic calorimeter is covered by the 10-cm thick iron absorber and plastic scintillation anti-coincidence counters.

## Results

[Data](/source/Data) collected with the **ND** experiment corresponds to the integrated [luminosity](/source/Luminosity) 19 pb−1. Results of the experiments with **ND** are presented in Ref.,[1] and are included in the [PDG](/source/Particle_Data_Group) Review. [23]

## References

1. Dolinsky, S. I. et al. (1991). "Summary of experiments with the neutral detector at the e+e− storage ring VEPP-2M". *Physics Reports*. **202** (3): 99–170. [Bibcode:1991PhR...202...99D](https://ui.adsabs.harvard.edu/abs/1991PhR...202...99D). [doi:10.1016/0370-1573(91)90127-8](https://doi.org/10.1016/0370-1573(91)90127-8)

1. Golubev, V. B. et al. (1984). "The neutral detector at VEPP-2M". *Nuclear Instruments and Methods in Physics Research Section A*. **227** (3): 467–469. [Bibcode:1984NIMPA.227..467G](https://ui.adsabs.harvard.edu/abs/1984NIMPA.227..467G). [doi:10.1016/0168-9002(84)90202-X](https://doi.org/10.1016/0168-9002(84)90202-X)

1. Dolinsky, S. I. et al. (1984). "Radiative decays of ρ and ω mesons". *[Zeitschrift für Physik C](/source/Zeitschrift_f%C3%BCr_Physik_C)*. **42** (4): 511–518. [doi:10.1007/BF01557655](https://doi.org/10.1007/BF01557655). [S2CID 122486080](https://api.semanticscholar.org/CorpusID:122486080)

1. Druzhinin, V. P. et al. (1984). "Measurement of Φ-meson radiative decays at the storage ring VEPP-2M with the neutral detector". *Physics Letters B*. **144** (1–2): 136–140. [Bibcode:1984PhLB..144..136D](https://ui.adsabs.harvard.edu/abs/1984PhLB..144..136D). [doi:10.1016/0370-2693(84)90192-8](https://doi.org/10.1016/0370-2693(84)90192-8)

1. Druzhinin, V. P. et al. (1987). "Search for rare radiative decays of Φ-meson at VEPP-2M". *[Zeitschrift für Physik C](/source/Zeitschrift_f%C3%BCr_Physik_C)*. **37** (1): 1–5. [Bibcode:1987ZPhyC..37....1D](https://ui.adsabs.harvard.edu/abs/1987ZPhyC..37....1D). [doi:10.1007/BF01442062](https://doi.org/10.1007/BF01442062). [S2CID 120341644](https://api.semanticscholar.org/CorpusID:120341644)

1. S.I. Dolinsky *et al.*, Sov. J. Nucl. Phys. 48 (1988) 277.

1. V. B. Golubev *et al.*, Sov. J. Nucl. Phys. 44 (1986) 409.

1. V. B. Vasserman *et al.*, Sov. J. Mod. Phys. 48 (1988) 480.

1. V. M. Aulchcnko *et al.*, Preprini INP 87-90 (Novosibirsk, 1987).

1. Dolinsky, S. I. et al. (1986). "The reaction e+e− → ωπ0 in the cm energy range from 1.0 to 1.4 GeV". *Phys. Lett. B*. **174** (4): 453–457. [Bibcode:1986PhLB..174..453D](https://ui.adsabs.harvard.edu/abs/1986PhLB..174..453D). [doi:10.1016/0370-2693(86)91036-1](https://doi.org/10.1016/0370-2693(86)91036-1)

1. A. D. Bukin *et al.*, Sov. J. Nucl. Phys. 50 (1989) 621.

1. Druzhinin, V. P. et al. (1986). "Investigation of the reaction e+e− → ηπ+π− in the energy range up to 1.4 GeV". *Phys. Lett. B*. **174** (1): 115–117. [Bibcode:1986PhLB..174..115D](https://ui.adsabs.harvard.edu/abs/1986PhLB..174..115D). [doi:10.1016/0370-2693(86)91140-8](https://doi.org/10.1016/0370-2693(86)91140-8)

1. V. M. Aulchenko *et al.*, Preprint INP 86-106 (Novosibirsk, 1987).

1. V. P. Druzhinin *et al.*, Preprint INP 85-98 (Novosibirsk, 1985).

1. V. M. Aulchcnko *et al.*, Preprint INP 86-173 (Novosibirsk, 1986).

1. V. B. Golubev *et al.*, Sov. J. Nucl. Phys. 41(1985) 752.

1. Aulchenko, V. M. et al. (1987). "The width of the ω-meson". *Phys. Lett. B*. **186** (3–4): 432–434. [Bibcode:1987PhLB..186..432A](https://ui.adsabs.harvard.edu/abs/1987PhLB..186..432A). [doi:10.1016/0370-2693(87)90322-4](https://doi.org/10.1016/0370-2693(87)90322-4)

1. P. V. Vorobyov *et al.*, Sov. J. Nucl. Phys. 48 (1988) 436.

1. V. P. Druzhinin *et al.*, Preprint INP 85-97 (Novosibirsk, 1985).

1. V. B. Golubev *et al.*, Sov. J. Nucl. Phys. 45 (1987) 622.

1. I. B. Vasserman *et al.*, JETP Lett. 43(1986) 588.

1. V. M. Aulchenko*et al.*, JETP Lett. 45 (1987) 145.

1. [The Review of Particle Physics](http://pdg.lbl.gov/index.html), [K. Nakamura et al. (Particle Data Group), J. Phys. G 37, 075021 (2010)](http://iopscience.iop.org/0954-3899/37/7A/075021)

## External links

- [Budker Institute of Nuclear Physics (BINP)](https://web.archive.org/web/20060207105713/http://www.inp.nsk.su/index.en.shtml)
- [VEPP-2M](http://www.inp.nsk.su/activity/old/vepp2m/index.ru.shtml)
- [NOVOSIBIRSK-ND experiment](https://inspirehep.net/experiments/1109662) record on [INSPIRE-HEP](/source/INSPIRE-HEP)

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Adapted from the Wikipedia article [ND experiment](https://en.wikipedia.org/wiki/ND_experiment) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/ND_experiment?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.