Enhanced leading production of D+- and D*+- in 250-GeV pi+- - nucleon interactions

The E769 collaboration Alves, G.A. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Rev.Lett. 72 (1994) 812-815, 1994.
Inspire Record 361344 DOI 10.17182/hepdata.42499

A leading charm meson is one with longitudinal momentum fraction, xF>0, whose light quark (or antiquark) is of the same type as one of the quarks in the beam particles. We report on the production asymmetry, A=[σ(leading-σ(nonleading)]/[σ(leading)+σ(nonleading)] as a function of xF. The data consist of 1500 fully reconstructed D± and D*± decays in Fermilab experiment E 769. We find a significant asymmetry for the production of charm quarks is not expected in perturbative quantum chromodynamics.

2 data tables match query

Asymmetry as function of XL.

Asymmetry as function of PT**2.


Transverse target spin asymmetries in exclusive $\rho^0$ muoproduction

The COMPASS collaboration Adolph, C ; Alekseev, M G ; Alexakhin, V Yu ; et al.
Phys.Lett.B 731 (2014) 19-26, 2014.
Inspire Record 1257385 DOI 10.17182/hepdata.66743

Exclusive production of $\rho^0$ mesons was studied at the COMPASS experiment by scattering 160 GeV/$c$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured as a function of $Q^2$, $x_{Bj}$, or $p_{T}^{2}$. The $\sin \phi_S$ asymmetry is found to be $-0.019 \pm 0.008(stat.) \pm 0.003(syst.)$. All other asymmetries are also found to be of small magnitude and consistent with zero within experimental uncertainties. Very recent calculations using a GPD-based model agree well with the present results. The data is interpreted as evidence for the existence of chiral-odd, transverse generalized parton distributions.

6 data tables match query

Single-spin azimuthal asymmetries for a transversely (T) polarised target and unpolarised (U) beam.

Single-spin azimuthal asymmetries for a transversely (T) polarised target and unpolarised (U) beam.

Single-spin azimuthal asymmetries for a transversely (T) polarised target and unpolarised (U) beam.

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Polarization at Small Angles in Anti-proton - Carbon Elastic Scattering at {LEAR} Energies

The SING collaboration Martin, A. ; Birsa, R. ; Bos, K. ; et al.
Nucl.Phys.A 487 (1988) 563-590, 1988.
Inspire Record 261245 DOI 10.17182/hepdata.37001

A double-scattering experiment of antiprotons on carbon has been carried out at the Low-Energy Antiproton Ring (LEAR) at CERN, to measure the polarization parameter A p C in antiproton-carbon elastic scattering at small angles. The polarization parameter has been inferred from the azimuthal distribution of the antiprotons after the second scattering. Data have also been collected with a liquid-hydrogen target as the second scatterer, thus allowing the sign of A p C to be determined. The experiment has been performed at two momenta of the extracted antiproton beam, 800 and 1100 MeV/c. A small positive value of the polarization has been observed, compatible with energy independence and a linear increase with the momentum transfer q . Parametrizing A p C as a c q , we get a c = +0.72 0.10 +0.09 ( GeV / c ) −1 . This result is compared with potential model predictions for N̄N amplitudes through a Glauber theory calculation.

6 data tables match query

THETA1(RF=LAB)=8 DEG, THETA POINTED IN TABLE IS THE SECOND SCATTERING ANGLE.

THETA1(RF=LAB)=5 DEG, THETA POINTED IN TABLE IS THE SECOND SCATTERING ANGLE.

THETA1(RF=LAB)=8 DEG, THETA POINTED IN TABLE IS THE SECOND SCATTERING ANGLE.

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Recoil properties of deep spallation and fragmentation products in the interaction of tantalum with 3.65-A-Gev C-12 ions and protons

Kozma, P. ;
Phys.Scripta 43 (1991) 133-136, 1991.
Inspire Record 299297 DOI 10.17182/hepdata.39412

Thick-target recoil properties of deep spallation and fragmentation products of the interaction of tantalum with 3.65 AGeV 12C-ions and 3.65 GeV protons have been studied. The kinematic parameters such as mean product kinetic energies and velocities of the remnant have been deduced from the data by means of the two-step vector velocity model of high-energy reactions. The results have also been used to test the applicability of the factorization hypothesis to the kinematic properties.

2 data tables match query

ASYM=F/B, WHERE F AND B ARE THE FRACTIONAL NUMBERS OF PRODUCT RECOILING INTO THE FORWARD AND BACKWARD CATCHER, RESPECTIVELY.

ASYM=F/B, WHERE F AND B ARE THE FRACTIONAL NUMBERS OF PRODUCT RECOILING INTO THE FORWARD AND BACKWARD CATCHER, RESPECTIVELY.


Energy Dependence of the Charge Asymmetry a ($T (\pi$), $\theta$) in $\pi d$ Elastic Scattering

Smith, G.R. ; Gill, D.R. ; Ottewell, D. ; et al.
Phys.Rev.C 38 (1988) 240-250, 1988.
Inspire Record 250814 DOI 10.17182/hepdata.26223

Angular distributions of charge asymmetry A(Tπ,θ), have been measured for πd elastic scattering. Data were obtained in the backward hemisphere for pion bombarding energies of 143, 180, 220, and 256 MeV. The results are compared with predictions employing different mass and width parameters for the delta isobars.

4 data tables match query

No description provided.

No description provided.

No description provided.

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Interactions of 200-GeV/nucleon O-16 and S-32 ions in nuclear emulsions

Baroni, G. ; Bisi, V. ; Breslin, A.C. ; et al.
Nucl.Phys.A 531 (1991) 691-708, 1991.
Inspire Record 313983 DOI 10.17182/hepdata.36711

This paper presents and contrasts features of the inelastic nuclear reactions of 200 GeV/nucleon 16 O and 32 S ions with emulsion nuclei. Both the multiplicities of shower particles and the extent of target fragmentation have been studied for varying degress of disruption of the projectile nuclei. The results may be interpreted within a simple geometrical model. In particular the rapidity distributions of those events which exhibit complete projectile break-up without any overt sign of low-energy target fragmentation have been determined. The interaction of secondary projectile fragments of charge two or more issuing from oxygen interactions were also studied and the mean free paths in emulsion of the primary 16 O and 32 S ions and all such fragments have been compared to those predicted by a simple Glauber model.

1 data table match query

No description provided.


SPIN EFFECTS IN CUMULATIVE PRODUCTION OF PROTONS AND DEUTERONS IN PROTON - NUCLEUS INTERACTIONS AT 16-GeV TO 64-GeV

Belyaev, I.M. ; Vlasov, N.V. ; Gavrishchuk, O.P. ; et al.
484-488, 1989.
Inspire Record 285499 DOI 10.17182/hepdata.38741

None

28 data tables match query

No description provided.

No description provided.

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Study of D+ and D- Feynman's x distributions in pi- nucleus interactions at the SPS

The WA82 collaboration Adamovich, M. ; Alexandrov, Y. ; Antinori, F. ; et al.
Phys.Lett.B 305 (1993) 402-406, 1993.
Inspire Record 354903 DOI 10.17182/hepdata.48370

Experiment WA82 studied charm production by a π − beam of 340 GeV/ c at the CERN Ω′ spectrometer, using a silicon microstrip vertex detector and an impact parameter trigger. Results on the x F distributions of D + and D − mesons are presented and discussed. A clear excess of D − over D + , increasing at high x F , is observed.

1 data table match query

No description provided.


Multiplicities of charged pions and kaons from semi-inclusive deep-inelastic scattering by the proton and the deuteron

The HERMES collaboration Airapetian, A. ; Akopov, N. ; Akopov, Z. ; et al.
Phys.Rev.D 87 (2013) 074029, 2013.
Inspire Record 1208547 DOI 10.17182/hepdata.62097

Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of \pi^\pm and K^\pm mesons. The data were collected by the HERMES experiment at the HERA storage ring using 27.6 GeV electron and positron beams incident on a hydrogen or deuterium gas target. The results are presented as a function of the kinematic quantities x_B, Q^2, z, and P_h\perp. They represent a unique data set for identified hadrons that will significantly enhance our understanding of the fragmentation of quarks into final-state hadrons in deep-inelastic scattering.

4 data tables match query

pi+ target asymmetries from HERMES, pi- target asymmetries from HERMES, VM subtracted, Z in the range 0.2-0.3.

pi+ target asymmetries from HERMES, pi- target asymmetries from HERMES, VM subtracted, Z in the range 0.3-0.4.

pi+ target asymmetries from HERMES, pi- target asymmetries from HERMES, VM subtracted, Z in the range 0.4-0.6.

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No description provided.