Measurement of the Collins and Sivers asymmetries on transversely polarised protons

The COMPASS collaboration Alekseev, M.G. ; Alexakhin, V.Yu. ; Alexandrov, Yu. ; et al.
Phys.Lett.B 692 (2010) 240-246, 2010.
Inspire Record 856645 DOI 10.17182/hepdata.55141

The Collins and Sivers asymmetries for charged hadrons produced in deeply inelastic scattering on transversely polarised protons have been extracted from the data collected in 2007 with the CERN SPS muon beam tuned at 160 GeV/c. At large values of the Bjorken x variable non-zero Collins asymmetries are observed both for positive and negative hadrons while the Sivers asymmetry for positive hadrons is slightly positive over almost all the measured x range. These results nicely support the present theoretical interpretation of these asymmetries, in terms of leading-twist quark distribution and fragmentation functions.

36 data tables

The COLLINS asymmetry for positively charged hadrons as a function of X.

The COLLINS asymmetry for positively charged hadrons as a function of Z.

The COLLINS asymmetry for positively charged hadrons as a function of PT.

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Measurement of the Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons in Polarised Muon DIS

The COMPASS collaboration Alekseev, M. ; Alexakhin, V.Yu. ; Alexandrov, Yu. ; et al.
Eur.Phys.J.C 64 (2009) 171-179, 2009.
Inspire Record 824774 DOI 10.17182/hepdata.52400

The longitudinal polarisation transfer from muons to lambda and anti-lambda hyperons, D_LL, has been studied in deep inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The spin transfers to lambda and anti-lambda produced in the current fragmentation region exhibit different behaviours as a function of x and xF . The measured x and xF dependences of D^lambda_LL are compatible with zero, while D^anti-lambda_LL tends to increase with xF, reaching values of 0.4 - 0.5. The resulting average values are D^lambda_LL = -0.012 +- 0.047 +- 0.024 and D^anti-lambda_LL = 0.249 +- 0.056 +- 0.049. These results are discussed in the frame of recent model calculations.

5 data tables

The weighted average of the spin transfers for the 2003 and 2004 data.

The XL dependence of the spin transfer from muons to the LAMBDA hyperon.

The X dependence of the spin transfer from muons to the LAMBDA hyperon.

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A measurement of the transverse polarization of Lambda-hyperons produced in n C reactions in the EXCHARM experiment.

The EXCHARM collaboration Aleev, A.N. ; Balandin, V.P. ; Dvalishvili, E.A. ; et al.
Eur.Phys.J.C 13 (2000) 427-432, 2000.
Inspire Record 509253 DOI 10.17182/hepdata.43333

New precise data of the$\Lambda^0$polarization are obtained in the EXCHARM experiment at the Serpukhov accelerator. The$\Lambda^0$

2 data tables

LAMBDA polarization as a function of PT for the whole XL region.

LAMBDA polarization as a function of PT for three XL regions.


A-dependence of Polarization of $\Lambda^0$ Produced Inclusively in Neutron - Nucleus Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Z.Phys.C 36 (1987) 27, 1987.
Inspire Record 237043 DOI 10.17182/hepdata.39599

TheA-dependence of the polarization ofΛ0,s produced inclusively in neutron-nucleus interactions at a mean neutron momentum of about 40 GeV/c has been measured in an experiment performed using the BIS-2 spectrometer at the Serpukhov accelerator. Carbon, Aluminium and Copper targets were used. TheΛ0,s were produced in the kinematical region of 0.6<pT<1.3 GeV/c and 0.2<xF<0.9. Describing the polarization of theΛ0,s by ℘=a·A a value of (−0.15+0.07/−0.60) was obtained by a fit to our data.

2 data tables

POLARIZATION IS DESCRIBED BY A POWER LOW: POL = C*A**B, WHERE C = -1.1, +0.4, -0.3 , A- ATOMIC NUMBER AND B = -0.15, +0.07, -0.6.


Polarization of Charmed $\Lambda(c$)+ Baryons Produced in Neutron - Carbon Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Yad.Fiz. 43 (1986) 619-623, 1986.
Inspire Record 209855 DOI 10.17182/hepdata.39660

None

3 data tables

No description provided.

No description provided.

No description provided.


Polarization of $\Lambda^0$ Produced by Neutrons With an Energy of Approximately 40-{GeV} on Carbon Nuclei

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Sov.J.Nucl.Phys. 37 (1983) 880, 1983.
Inspire Record 183323 DOI 10.17182/hepdata.39542

None

1 data table

No description provided.


MEASUREMENTS OF LAMBDA0 POLARIZATION PRODUCED BY 40-GeV NEUTRONS ON CARBON NUCLEI IN INCLUSIVE PROCESSES

The Dubna-Berlin-Moscow-Prague-Sofiya-Tbilisi collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
JINR-P1-81-165, 1981.
Inspire Record 165431 DOI 10.17182/hepdata.39207

None

1 data table

No description provided.