Bosted, P.E.
Strange production
[10.0, 100.0]
Max results
Sort by Reverse order

Showing 10 of 11 results

Asymmetries in the production of Lambda0 in 250-GeV/c pi+-, K+- and p nucleon interactions.

The E769 collaboration Alves, G.A ; Amato, S ; Anjos, J.C ; et al.
Phys.Lett.B 559 (2003) 179-186, 2003.
Inspire Record 615414 DOI 10.17182/hepdata.41928

Using data from Fermilab fixed-target experiment E769, we have measured particle-antiparticle production asymmetries for Lambda0 hyperons in 250 GeV/c pi+-, K+- and p -- nucleon interactions. The asymmetries are measured as functions of Feynman-x (x_F) and p_t^2 over the ranges -0.12<=x_F<=0.12 and 0<=p_t^2<=3 (GeV/c)^2 (for positive beam) and -0.12<=x_F<=0.4 and 0<=p_t^2<=10 (GeV/c)^2 (for negative beam). We find substantial asymmetries, even at x_F around zero. We also observe leading-particle-type asymmetries. These latter effects are qualitatively as expected from valence-quark content of the target and variety of projectiles studied.

4 data tables
Table 1

LAMBDA production asymmetries versus XL for the positive beams.

Table 2

LAMBDA production asymmetries versus PT**2 for the positive beams.

Table 3

LAMBDA production asymmetries versus XL for the negative beams.

More…

Forward cross-sections for production of D+, D0, D/s, D*+ and Lambda/c in 250-GeV pi+-, K+-, and p nucleon interactions.

The E769 collaboration Alves, G.A. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Rev.Lett. 77 (1996) 2388-2391, 1996.
Inspire Record 418771 DOI 10.17182/hepdata.42294

We measure forward cross sections for production of D+, D0, Ds, D*+, and Λc in collisions of π±, K±, and p on a nuclear target. Production induced by different beam particles is found to be the same within statistics. Strange and baryonic final states are seen to contribute appreciably to the total charm cross section, which our measurements indicate is larger than but consistent with QCD predictions. The energy dependence mapped out by these and previous measurements is consistent with theory. Leading-particle asymmetry measurements for K and p-induced charm production are also presented.

8 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Beam flavor dependence in the hadroproduction of D+- and D(s)+- mesons

The E769 collaboration Wallace, A. ; Alves, G.A. ; Amato, S. ; et al.
FERMILAB-CONF-94-184-E, 1994.
Inspire Record 375038 DOI 10.17182/hepdata.43049

None

10 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Production of $\Lambda(c$) With Large X(f) at the {ISR}

The R608 collaboration Chauvat, P. ; Cousins, R. ; Hayes, K. ; et al.
Phys.Lett.B 199 (1987) 304, 1987.
Inspire Record 250761 DOI 10.17182/hepdata.30058

We report results of an inclusive measurement of the charmed baryon, Λ c , in the forward direction of proton-proton interactions with s =63 GeV . The signal, seen in the final state Λ s π + π + π − , has 6.0 σ significance with about 620 events on a large background and corresponds to a cross section times branching ratio of 2.84±0.50±0.72 μ b for Feynman- x F > 0.5 in both hemispheres. Asymmetries are observed in the decay angular distributions which are characteristic of weak decays and have a combined 3.0 σ significance.

1 data table
Table 1

BR. RATIO WAS TAKEN TO BE 0.028+-0.007+-0.011.


$\Lambda^0$ 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.


Evidence for Pomeron Single Quark Interactions in Proton Diffraction at the {ISR}

The R608 collaboration Smith, A.M. ; Meritet, L. ; Reyrolle, M. ; et al.
Phys.Lett.B 163 (1985) 267-272, 1985.
Inspire Record 216801 DOI 10.17182/hepdata.30332

Measurements are presented of two exclusive diffractive reactions, pp → (Λ 0 φ 0 K + ) p and pp → (Λ 0 Λ 0 p)p , at √ s = 63 GeV . Pronounced correlations with the beam direction are observed (in the rest frame of the forward-going bracketed system) for those outgoing particles which contain the beam valence quarks. In each case there is a forward-Λ 0 in correlation with a backward K + or p, respectively. No such behavior is seen for the particles which do not contain beam valence quarks (φ 0 and Λ 0 , respectively) . Interpreted as examples of pomeron-proton scattering, these results constitute evidence that, for these final states, the pomeron interacts with a single valence quark and apparently back-scatters it. The subsequent hadronization leads to a longitudinal event structure.

3 data tables
Table 1

Cross sections for forward LAMBDA signal counting both arms of the p p interaction.

Table 2

Cross sections for forward LAMBDA signal counting both arms of the p p interaction.

Table 3

No description provided.


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).


OBSERVATION OF POLARIZATION IN DIFFRACTIVE DISSOCIATION p ---> LAMBDA0 K+ AT THE CERN ISR

Erhan, S. ; Hayes, K. ; Smith, A.M. ; et al.
62-65, 1984.
Inspire Record 202932 DOI 10.17182/hepdata.49652

None

1 data table
Table 1

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.


THE REACTIONS P P ---> P P PI+ PI-, K+ P ---> K+ P PI+ PI-, PI+ P ---> PI+ P PI+ PI- AND PI- P ---> PI- P PI+ PI- AT 147-GeV/c

Brick, D.H. ; Rudnicka, H. ; Shapiro, A.M. ; et al.
Z.Phys.C 19 (1983) 1-9, 1983.
Inspire Record 194363 DOI 10.17182/hepdata.16321

We have studied the reactionspp→ppπ+π-,K+p→K+pπ+π−π, π+p→ π+,pπ+π− and π−p →π+π− at 147 GeV/c using the 30-inch Fermilab hybrid system. All four reactions were detected with the same apparatus and analyzed in the same way. The energy dependence of the channel cross section was found to beAp−0.6+B for thepp reaction andAp−1+B for the other three. About 90% of the cross section at 147 GeV/c can be accounted for by either beam or target diffraction. Some of the remaining cross section may come from double Pomeron exchange reactions which we tried to isolate. We have tested the hypothesis of a factorizable Pomeron and our data indicates a violation of this hypothesis. We show that the 3π mass enhancement in the mass region 1.2–1.4 GeV is diffractively produced in the π± beam reactions. Fourprong, four-constraint and six-prong, four-constraint cross sections are reported.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

CROSS SECTIONS FOR DIFFRACTION DISSOCIATION OF BEAM. FEYNMAN X OF OUTGOING PROTON <-0.96.

More…