HEPData Search

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Precision measurements of $g_1$ of the proton and the deuteron with 6 GeV electrons

The CLAS collaboration Prok, Y. ; Bosted, P. ; Kvaltine, N. ; et al.

Phys.Rev.C 90 (2014) 025212, 2014.

Inspire Record 1292133 DOI 10.17182/hepdata.64411

The inclusive polarized structure functions of the proton and deuteron, g1p and g1d, were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at lab angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual DIS kinematics, Q^2>1 GeV^2 and the final-state invariant mass W>2 GeV, the ratio of polarized to unpolarized structure functions g1/F1 is found to be nearly independent of Q^2 at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative QCD, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.

4 data tables

Table 1

Results for G1(P)/F1(P) for the proton in bins of (XB;Q**2), along with average kinematic values and correction factors for each bin. All values are averaged over the event distribution.

Table 2

Results for G1(DEUT)/F1(DEUT) for the deuteron in bins of (XB;Q**2), along with average kinematic values and correction factors for each bin. All values are averaged over the event distribution.

Table 3

Results for G1(P)/F1(P) for the proton in bins of (W;Q**2), along with average kinematic values and correction factors for each bin. All values are averaged over the event distribution.

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Study of the Reaction $\bar{p} p \to p X$ at 22.4-{GeV}/$c$

The Alma Ata-Dubna-Helsinki-Kosice-Moscow-Prague-Tbilisi collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Dashian, N.B. ; et al.

Sov.J.Nucl.Phys. 33 (1981) 64-66, 1981.

Inspire Record 154173 DOI 10.17182/hepdata.69635

None

49 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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POLARIZATION EFFECTS IN RHO0 MESON PRODUCTION IN ANTI-PROTON PROTON INTERACTIONS AT 22.4-GEV/C, 12-GEV/C, AND 5.7-GEV/C

Batyunya, B.V. ; Boguslavsky, I.V. ; Boos, E.G. ; et al.

Phys.Rev.Lett. 55 (1985) 562-565, 1985.

Inspire Record 221353 DOI 10.17182/hepdata.20274

The ρ0-meson spin alignment is studied in p¯p interactions at 22.4 and 12 GeV/c and in the reaction p¯p→2π++2π−+neutrals at 5.7 GeV/c. An essential ρ0-meson spin alignment is observed. The values of the ρ00T element of the ρ0-meson spin-density matrix in the transversity frame are 0.56 ± 0.07, 0.53 ± 0.05, and 0.54 ± 0.04 for the above-mentioned interactions, respectively. An increase of ρ00T with ρ0 transverse momentum is obtained.

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Evidence for a 1.9-{GeV} Meson Decaying Into $\eta \eta^\prime$

The IFVE-Brussels-Annecy-Los Alamos collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 216 (1989) 447, 1989.

Inspire Record 267048 DOI 10.17182/hepdata.29856

Evidence for a new meson decaying into ηη′ has been found in 38 GeV π − p charge-exchange interactions. The mass and the width of this meson are (1917 ± 15) MeV and (90 −50 +35 ) MeV, respectively. Possible spin and parity assignments are J PC = 0 ++ , 1 −+ or 2 ++ , isospin and G -parity are I G = 0 + . The t -dependence of the differential cross section follows an exponential behaviour exp( bt with a small slope: b = (2±1) (GeV/ c ) −2 .Upper limits on its decay into ππ, ηη and K K exotic interpretation of this meson.

1 data table

Table 1

No description provided.

Study of $\omega \omega$ Systems Produced in 38-{GeV}/$c \pi^- p$ Collisions

The IHEP-IISN-LANL-LAPP-TSUIHEP collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 216 (1989) 451, 1989.

Inspire Record 267049 DOI 10.17182/hepdata.29857

The π − p→ ωω n reaction has studied for the first time at the 70 GeV IHEP accelerator. The six photons from the decay of the two ω mesons were detected in GAMS-2000, a hodoscope multi-photon spectometer. Two resonances decaying into ωω,X (1640) and X(1960), have been observed. Their quantum numbers are J PC =2 ++ , I G =0 + . The reaction is dominated by the one-pion exchange mechanism. The production cross sections σ. BR(X→ ωω ) are 0.65±0.15 μ b and 1.0±0.2 μ b, respectively.

2 data tables

Table 1

X(1640) IS A JPC - 2++, IG - 0+ MESON WITH MASS 1643+-7 MEV.

Table 2

X(1960) IS A JPC - 2++, IG - 0+ MESON WITH MASS 1956+-20 MEV.

K0(L) K0(s) Transmission Regeneration on Hydrogen

The Budapest-Dubna-Prague-Serpukhov collaboration Birulev, V.K. ; Genchev, V. ; Govorun, N.N. ; et al.

Nucl.Phys.B 115 (1976) 249-268, 1976.

Inspire Record 3964 DOI 10.17182/hepdata.35585

The energy dependence of the modulus and phase of the K L 0 -K S 0 regeneration amplitude on hydrogen in the range of 14–50 GeV has been investigated at the Serpukhov 70 GeV accelerator. It has been established that the modulus of the modified regeneration amplitude decreases with increasing momentum as 2|ƒ 21 0 (p)|/k = (0.84 ± 0.42) · p −0.50±0.15 mb . The amplitude phase is energy-independent and its mean value is ϕ 21 0 = −132° ± 5°. The results obtained are compared with other experiments and with predictions of different theoretical models.

1 data table

Table 1

TABLE ALSO CALCULATES FORWARD DIFFERENTIAL CROSS SECTION AND SIG(AK0 P) - SIG(K0 P) TOTAL CROSS SECTION DIFFERENCES.