Multiwire proportional chambers in the HERMES experiment

Andreev, A. V.; Belostotski, S.; Gavrilov, G.; Grebenjuk, O; Ivanov, E.; Kisselev, A.; Krivchitch, A.; Kozlov, Sergey M.; Maleev, V. P.; Miklukho, O. V.; Naryshkin, Y.; Patrichev, S.; Razmyslovich, V.; Trophimov, V; Vassiliev, A.; Vikhrov, V.; Cisbani, E.; Colilli, S.; Frullani, S.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Iodice, M.; Lucentini, M.; Santavenere, F.; Urciuoli, G. M.

doi:10.1016/s0168-9002(01)00691-x

Cited by 11 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The anode planes were contained within a pressure volume filled with an Ar:CO 2 :CF 4 65:30:5 mixture to provide the medium for ionization. This gas mixture and the voltage anode plane operation voltage (3200 V) were chosen by consideration of simulations of the detectors using the GARFIELD gas ionization and drift software package [141] and experience operating similar detectors at the HERMES experiment [142].…”

Section: Multi-wire Proportional Chambers (Mwpcs)mentioning

confidence: 99%

“…hit-finder. Initial hit decisions for single wires were produced by software adapted from the software used for the HERMES experiment MWPCs [142,184] adapted by the PNPI group. While, in principle, single wire 1D hits could be passed to the track reconstruction algorithm used for the 12 • system, the combination of information from the three wires in a chamber provided an important means of rejecting noise hits.…”

Section: Mwpc Detectorsmentioning

confidence: 99%

See 1 more Smart Citation

A precision measurement of the e+p/e-p elastic scattering cross section ratio at the OLYMPUS experiment

Henderson¹

2017

Preprint

View full text Add to dashboard Cite

Measurements of the ratio of the proton elastic form factors (µ p G E /G M ) using Rosenbluth separation and those using polarization-based techniques show a strong discrepancy, which has persisted both in modern experimental results and in re-analyses of previous data. The most widely accepted hypothesis to explain this discrepancy is the treatment of the contributions from hard two-photon exchange (TPE) to elastic electron-proton scattering in the radiative corrections applied to the Rosenbluth separation measurements. Calculations of the hard TPE contribution are highly model dependent, but the effect may be measured experimentally with a precise determination of the ratio of the positron-proton and electron-proton elastic scattering cross sections.The OLYMPUS experiment collected approximately 4 fb −1 of e + p and e − p scattering data at the DORIS storage ring at DESY in 2012, with the goal of measuring the elastic σ e + p /σ e − p ratio over the kinematic range (0.4 ≤ ≤ 0.9), (0.6 ≤ Q 2 ≤ 2.2) GeV 2 /c 2 at a fixed lepton beam energy of 2.01 GeV. The detector for the OLYMPUS experiment consisted of refurbished elements of the Bates Large Acceptance Spectrometer Toroid (BLAST) surrounding an internal gaseous hydrogen target, with the addition of multiple systems for the monitoring of the luminosity collected by the experiment. A detailed simulation of the experiment was developed to account for both radiative corrections and various systematic effects.This work presents preliminary results from the OLYMPUS data, demonstrating that the elastic σ e + p /σ e − p ratio rises to several percent at ≈ 0.4 and indicating a significant contribution from TPE to e ± p scattering. Additionally, the value of σ e + p /σ e − p has been measured to unprecedented precision at = 0.98, which provides a valuable normalization point for other experimental data.

show abstract

Section: Multi-wire Proportional Chambers (Mwpcs)mentioning

confidence: 99%

Section: Mwpc Detectorsmentioning

confidence: 99%

A precision measurement of the e+p/e-p elastic scattering cross section ratio at the OLYMPUS experiment

Henderson¹

2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Detailed descriptions of these components can be found in refs. [54][55][56][57][58][59]. Positrons within the acceptance could be separated from hadrons with an efficiency exceeding 98% and a hadron contamination of less than 1%.…”

Section: The Hermes Experimentsmentioning

confidence: 99%

Leading-order determination of the gluon polarization from high-p T hadron electroproduction

Airapetian¹,

Акопов²,

Akopov³

et al. 2010

J. High Energ. Phys.

View full text Add to dashboard Cite

Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum p T have been measured in electroproduction using the Hermes detector at Hera. Processes involving gluons in the nucleon have been enhanced relative to others by selecting hadrons with p T typically above 1 GeV. In this kinematic domain the gluon polarization has been extracted in leading order making use of the model embedded in the Monte Carlo Generator Pythia 6.2. The gluon polarization obtained from single inclusive hadrons in the p T range 1 GeV < p T < 2.5 GeV using a deuterium target is ∆g g (x , µ 2) = 0.049 ± 0.034(stat) ± 0.010(sys-exp) +0.126 −0.099 (sys-models) at a scale µ 2 = 1.35 GeV 2 and x = 0.22. For different final states and kinematic domains, consistent values of ∆g g have been found within statistical uncertainties using hydrogen and deuterium targets.

show abstract

“…These low-momentum pions are often bent so severely in the spectrometer magnet that they fail to reach the tracking chambers and particle identification detectors in the backward half of the spectrometer. However, it is possible to evaluate the momentum of such "short tracks" using the hits recorded by the HERMES Magnet Chambers, a series of proportional chambers located between the poles of the spectrometer magnet [21]. The acceptance for Λ hyperons can be increased by almost a factor of two when these pion "short tracks" are included in the analysis.…”

Section: Event Selectionmentioning

confidence: 99%

Transverse polarization ofΛandΛ¯hyperons in quasireal photoproduction

Airapetian¹,

Акопов²,

Akopov³

et al. 2007

Phys. Rev. D

View full text Add to dashboard Cite

The HERMES experiment has measured the transverse polarization of Λ andΛ hyperons produced inclusively in quasireal photoproduction at a positron beam energy of 27.6 GeV. The transverse polarization P Λ n of the Λ hyperon is found to be positive while the observedΛ polarization is compatible with zero. The values averaged over the kinematic acceptance of HERMES are P Λ n = 0.078 ± 0.006 (stat) ± 0.012 (syst) and PΛ n = −0.025 ± 0.015 (stat) ± 0.018 (syst) for Λ andΛ, respectively. The dependences of P Λ n and PΛ n on the fraction ζ of the beam's light-cone momentum carried by the hyperon and on the hyperon's transverse momentum pT were investigated. The measured Λ polarization rises linearly with pT and exhibits a different behavior for low and high values of ζ, which approximately correspond to the backward and forward regions in the center-of-mass frame of the γ * N reaction.

show abstract

Multiwire proportional chambers in the HERMES experiment

Cited by 11 publications

References 8 publications

A precision measurement of the e+p/e-p elastic scattering cross section ratio at the OLYMPUS experiment

A precision measurement of the e+p/e-p elastic scattering cross section ratio at the OLYMPUS experiment

Leading-order determination of the gluon polarization from high-p T hadron electroproduction

Transverse polarization ofΛandΛ¯hyperons in quasireal photoproduction

Contact Info

Product

Resources

About