HAL Id: jpa-00221858
https://hal.archives-ouvertes.fr/jpa-00221858
Submitted on 1 Jan 1982
HAL
is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire
HAL, estdestinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
RESULTS ON HADRON PRODUCTION AT CESR
F. Pipkin
To cite this version:
F. Pipkin. RESULTS ON HADRON PRODUCTION AT CESR. Journal de Physique Colloques,
1982, 43 (C3), pp.C3-40-C3-41. �10.1051/jphyscol:1982305�. �jpa-00221858�
JOURNAL DE PHYSIQUE
CoZZoque C3, suppte'ment au n o 12, Tome 43, de'cembre 1982 page c3-40
R E S U L T S ON HADRON PRODUCTION A T CESR
Presented b y F.M. Pipkin
Department o f P h y s i c s , Harvard U n i v e r s i t y , Cambridge, MA 021 38, U. S .A.
I.
CUSB
(Columbia, Stonybrook, Louisiana State, Munich, Cornell)The CUSB detector was used to search for new narrow resonances in the c.m. regions below the T (3s) [lo. 24 GeV
-
10.3 G~v], between the T(3S) and the T(4S), and above the T(4S) [up to 10.6 G~v]. The upper limits on the leptonic widths of such states are, respectively, 25 eV, 20 eV, and 200 eV. The average value of R increased by 0.31'0.06 across the flavor threshold near the T(4S).11.
-
CLEO (Cornell, Harvard, Ohio State, Rochester, Rutgers, Syracuse, Vanderbilt)Inclusive charged D*(2010) production from non-resonant e+e- annihilation was mea- sured in the center-of-mass energy range 10.2 GeV<W<10.6 GeV. Charged D* mesons were identified through the cascade D*++DoT+-+K-T+~- and the charge conjugate mode.
All KTI and KITIT mass combinations were formed; each detected charged particle entered under both K and IT mass hypotheses. Figure 1 shows the observed (KITIT)-(KIT) mass difference (A) for D*'s with z = (2EIW)zO. 7 when the KIT mass is within +45 M ~ V / C ~ of the Do mass together with the background determined from the neighboring inter- vals of KIT mass. To identify a D*+ it was required that the K-a+ mass be within '45 M ~ V / C ~ of the DO mass and that A be within +1.5 M ~ V / C ~ of the D*+-DO mass dif- ference. Figure 2 shows the charged D* differential cross section w2do/dz. The charmed D* cross section is 1.1?0.3+0.4 nb for z>0.5 and 0.6kO.lf0.2 nb for z>0.7 where the errors are statistical and systematic respectively.
Fig. 1 - Measured KITIT-KIT mass difference Fig. 2 - Differential cross sections for z>0.7 and KIT within 245 MeV/c for D*', D' and Do.
of Do mass.
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1982305
F.M. Pipkin
&
The cross sections for inclusive production of Kf,
p,
KO, KO, A, $I, K*' and K*' hadrons were measured on the T(lS), T(3S), T(4S) and the continium near the T(4S).The time-of-flight and dE/dx systems were used to identify kaons in the momentum range 0.45 GeVfc-< pK < 1.0 GeVfc and protons in the range 0.65 GeV/c < pp < 1.45 GeVfc. The KO, KO, A, $, and K*'S were identified through mass plots. Figure 3 shows the scaling cross sections on the T(1S) and the continium for the kaons, anti- protons, and lambdas. The cross sections for the T(3S) were similar to those for the T(1S). The Lund Monte Carlo was used to extrapolate the data outside the ob- served momentum range and determine the number of hadrons per event. Table I sum- marizes the results of this calculation. The most striking feature is the difference in the number of baryons produced on the T(1S) or T(3S) and the continium. The ratio of the number of A's to the number of KO's increases with momentum more rapidly on the T(1S) and T(3S) than on the continium. The T(4S) is distinctive in that there are more kaons per event and there is little evidence for baryon production.
CONTINUUM
.
n0 d x 2 8 0 I*
- +
Fig. 3 - Scaling cross sections for A, 2p, K-, and KO
Table I. Corrected number of hadrons per event Particle
K+
KO,
KO
Continium 0.90(04) 0.89(04) 0.08 (01) 0.27(02) 0.11 (04) 0.43(13) 0.55(15)
3) Measurement of Charged Pion Fraction at
...
W = 10.5 GeVTwo high pressure threshold gas Cerenkov Counters were used to extend the momentum range in which pions could be identified up to 4 GeV. The charged pion fraction was measured to be 0.574+0.059 for hadrons with 1.5 GeV/c < p < 4.0 GeV/c. These data indicate that for fragmentation into high momentum hadrons the probability of picking up a strange quark from the sea is greater than the u:d:s ratio .45:.45:.10 used in some models.
