Cheze, J.B.
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Spin transfer in inclusive Lambda0 production by transversely polarized protons at 200-GeV/c.

The E704 collaboration Bravar, A. ; Adams, D.L. ; Akchurin, N. ; et al.
Phys.Rev.Lett. 78 (1997) 4003-4006, 1997.
Inspire Record 449327 DOI 10.17182/hepdata.19560

Surprisingly large polarizations in hyperon production by unpolarized protons have been known for a long time. The spin dynamics of the production process can be further investigated with polarized beams. Recently, a negative asymmetry AN was found in inclusive Λ0 production with a 200GeV/c transversely polarized proton beam. The depolarization DNN in p↑+p→Λ0+X has been measured with the same beam over a wide xF range and at moderate pT. DNN reaches positive values of about 30% at high xF and pT∼1.0GeV/c. This result shows a sizable spin transfer from the incident polarized proton to the outgoing Λ0.

6 data tables
Table 1

Errors are statistical only. The systematic errors are estimated to be negligible.

Table 2

Errors are statistical only. The systematic errors are estimated to be negligible.

Table 3

Errors are statistical only. The systematic errors are estimated to be negligible.

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Test of {CP} Invariance in $\Lambda^0$ Decay

The R608 collaboration Chauvat, P. ; Erhan, S. ; Hayes, K. ; et al.
Phys.Lett.B 163 (1985) 273-276, 1985.
Inspire Record 216802 DOI 10.17182/hepdata.49640

In an experiment at the CERN intersecting storage rings with √ s = 31 GeV, we have measured αP , the product of asymmetry parameter and polarization, for Λ 0 's and Λ 0 's produced in p p and pp interactions, respectively. The ratio, (αP) Λ /(αP Λ = −1.04±0.29 , is consistent with the value −1, and constitutes the first test of CP invariance in Λ decay.

1 data table
Table 1

The ratio CONST/CONST is obtained under assumption of POL(LAMBDA) = POL(LAMBDABAR).


Analyzing power measurement in inclusive Lambda0 production with a 200-GeV/c polarized proton beam

The E704 collaboration Bravar, A. ; Adams, D.L. ; Akchurin, N. ; et al.
Phys.Rev.Lett. 75 (1995) 3073-3077, 1995.
Inspire Record 406598 DOI 10.17182/hepdata.19610

The considerable polarization of hyperons produced at high xF has been known for a long time and has been interpreted with various theoretical models in terms of the constituents' spin. Recently, the analyzing power in inclusive Λ0 hyperon production has also been measured using the 200GeV/c Fermilab polarized proton beam. The covered kinematic range is 0.2≤xF≤1.0 and 0.1≤pT≤1.5GeV/c. The data indicate a negative asymmetry at large xF and moderate pT. These results can further test the current ideas on the underlying mechanisms for hyperon polarization.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Analysis of Transverse Momentum Distributions for $p p$ Interactions at 360-{GeV}/$c$ in the Framework of a Quark - Diquark Fragmentation Model

The EHS-RCBC collaboration Bailly, J.L. ; Bruyant, F. ; Buschbeck, B. ; et al.
Z.Phys.C 35 (1987) 295, 1987.
Inspire Record 245106 DOI 10.17182/hepdata.15802

Using a quark-diquark fragmentation model, in which either the Field-Feynman or the Lund model is coupled with a quark-diquark distribution function, we study transverse momentum distributions,pT, for the inclusive reactionspp→hadron +anything at 360 GeV/c. We find that a primordial mean transverse momentum 〈kT〉≃0.4 GeV/c can well reproduce thepT2 distributions of charged hadrons, π0,Ks0, Λ0,K* and Σ* and the Feynmanx−pT correlations. We confirm that a diquark in a proton plays an important rôle in reproducing thex−pT correlation of Λ0.

1 data table
Table 1

No description provided.


Inclusive $K^0_S$, $\Lambda$ and $\bar{\Lambda}$ Production in 360-{GeV}/$c p p$ Interactions Using the European Hybrid Spectrometer

The EHS-RCBC & Bombay-CERN-Genoa-Innsbruck-Japan-Madrid-Mons-Rutgers-Serpukhov-Tennessee-Vienna collaborations Asai, M. ; Bailly, J.L. ; Banerjee, S. ; et al.
Z.Phys.C 27 (1985) 11, 1985.
Inspire Record 202938 DOI 10.17182/hepdata.16100

Results on cross sections, longitudinal and transverse momentum distributions forKs/0, Λ and\(\bar \Lambda \) production in 360GeV/cpp interactions are presented as obtained from EHS equipped with the Rapid Cycling Bubble Chamber (RCBC). The Λ and\(\bar \Lambda \) polarizations are measured. The cross section for the diffractive components is given using the recoil spectrum. The data are discussed with respect to charm production.

1 data table
Table 1

No description provided.


$\Lambda^0$ Polarization in Proton Proton Interactions From $sqrt{s} = 31$-{GeV} to 62-{GeV}

The R608 collaboration Smith, A.M. ; Bonino, R. ; Castellina, A. ; et al.
Phys.Lett.B 185 (1987) 209, 1987.
Inspire Record 235588 DOI 10.17182/hepdata.30196

We report Λ 0 -hyperon polarization measurements at the CERN intersecting storage rings from √ s of 31 to 62 GeV. P Λ 0 changes insignificantly, +(0.8±1.7)%, over this range of √ s . However, P Λ 0 is observed to grow with Feynman- x F and with transverse momentum. At an average p t of 1.1 GeV/ c , P Λ 0 depends linearly on x F and approaches −40% at x F =0.8.

1 data table
Table 1

No description provided.


K0 and Lambda Production at the CERN ISR

Busser, F.W. ; Camilleri, L. ; Di Lella, L. ; et al.
Phys.Lett.B 61 (1976) 309-312, 1976.
Inspire Record 101076 DOI 10.17182/hepdata.5534

Transverse momentum distributions of λ o , λ o , and K o , produced in pp collisions at x = 0, have obtained at the CERN ISR. The K o yield is in agreement with published K + , K − results, obtained at this centre-of-mass energy (√ s ≈44 GeV). The results on λ o and λ o production obtained in this experiment are compared with results obtained at lower centre-of-mass energies.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Differences in Leading Baryon Production From $p \bar{p}$ and $p p$ Collisions With $\sqrt{s}=31$-{GeV} at the {CERN} {ISR}

Chauvat, P. ; Cousins, R.D. ; Erhan, S. ; et al.
Phys.Lett.B 127 (1983) 384-388, 1983.
Inspire Record 190333 DOI 10.17182/hepdata.30717

Significant differences are observed between forward-produced Δ ++ (1232) and Λ 0 's in pp interactions and their corresponding anti-particles in p p interactions, as expected from quark counting and single q q annihilation. A possible relationship between these results and the p p -pp total cross section difference is discussed.

2 data tables
Table 1

No description provided.

Table 2

No description provided.