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MEASUREMENT OF PI- P ---> PI- PI+ N NEAR THRESHOLD AND CHIRAL SYMMETRY BREAKING

Bjork, C.W. ; Jones, S.E. ; King, T.R. ; et al.

Phys.Rev.Lett. 44 (1980) 62-65, 1980.

Inspire Record 157275 DOI 10.17182/hepdata.20699

d2σdΩdT for π+ mesons produced in π−p→π−π+n was measured at seven incident energies between 203 and 357 MeV and the integrated reaction cross section was calculated. The matrix element, when extrapolated to threshold and compared with soft-pion calculations, determined the chiral-symmetry-breaking parameter ξ=0.05±0.26, which is consistent with the Weinberg Lagrangian. The large hard-pion contributions at 203 MeV demonstrated the absolute necessity for comparing at threshold.

1 data table

Table 1

Axis error includes +- 0.0/0.0 contribution (?////).

Observation of Three Upsilon States

The CLEO collaboration Andrews, D. ; Berkelman, Karl ; Billing, M. ; et al.

Phys.Rev.Lett. 44 (1980) 1108, 1980.

Inspire Record 152393 DOI 10.17182/hepdata.20733

Three narrow resonances have been observed in e+e− annihilation into hadrons at total energies between 9.4 and 10.4 GeV. Measurements of mass spacing and ratios of lepton pair widths support the interpretation of these "ϒ" states as the lowest triplet-S levels of the bb¯ quark-antiquark system.

1 data table

Table 1

No description provided.

Observation of a Fourth Upsilon State in e+ e- Annihilations

The CLEO collaboration Andrews, D. ; Berkelman, Karl ; Cabenda, R. ; et al.

Phys.Rev.Lett. 45 (1980) 219, 1980.

Inspire Record 153182 DOI 10.17182/hepdata.20674

A fourth state in the upsilon energy region has been seen in e+e− collisions at the Cornell Electron Storage Ring. A resonance is observed with a mass 1112±5 MeV above the lowest upsilon state. The 9.6-MeV rms width is greater than the 4.6-MeV energy resolution of the e+e− beams. The observed characteristics of the new state make it a likely candidate for the 4S3 state of the bb¯ system, lying above the threshold for the production of B mesons.

1 data table

Table 1

NOT CORRECTED FOR TAU HEAVY LEPTON PRODUCTION NOR TWO-PHOTON COLLISIONS.

Inclusive Charged $D^*$ Production in $e^+ e^-$ Annihilations at $W=10$.4-{GeV}

The CLEO collaboration Bebek, C. ; Hassard, J. ; Hempstead, M. ; et al.

Phys.Rev.Lett. 49 (1982) 610, 1982.

Inspire Record 178490 DOI 10.17182/hepdata.20565

A measurement is presented of inclusive charged D*(2010) production from nonresonant e+e− annihilation in the center-of-mass energy (W) range 10.2 GeV<W<10.6 GeV. Charged D* mesons are identified by the decays D*+→D0π+→K−π+π+ and the charge conjugate mode. It is found that 40 ± 7 ± 13% of the charm quarks from the process e+e−→cc¯ result in D* mesons with z>0.7 (z=2EW, where E is the D* energy).

2 data tables

Table 1

No description provided.

Table 2

No description provided.

High Precision Measurement of the $\Upsilon$ Meson Mass

Artamonov, A.S. ; Baru, S.E. ; Blinov, A.E. ; et al.

Phys.Lett.B 118 (1982) 225, 1982.

Inspire Record 178785 DOI 10.17182/hepdata.37137

A high precision measurement of the υ-meson mass has been performed at the storage ring VEPP-4 using the MD-1 detector. The resonance depolarization method has been used for the absolute calibration of the beam energy that allowed to improve the accuracy of υ-mass measurement by a factor of ten. The following mass value has been obtained: M = 9459.7 ± 0.6 MeV.

1 data table

Table 1

No description provided.

rivet Analysis
A Measurement of the Branching Fraction of the Decay $\Upsilon$ (1s) $\to \tau^+ \tau^-$

The CLEO collaboration Giles, R. ; Hassard, J. ; Hempstead, M. ; et al.

Phys.Rev.Lett. 50 (1983) 877, 1983.

Inspire Record 188803 DOI 10.17182/hepdata.20525

The branching fraction for the decay of the ϒ(1S) into τ paris has been measured to be (3.4±0.4±0.4)%. This result agrees with the previously measured branching ratio of the decay into muon pairs.

2 data tables

Table 1

VISIBLE CROSS SECTIONS IN THE PEAK.

Table 2

No description provided.

Evidence for the F Meson at 1970-MeV

The CLEO collaboration Chen, A. ; Goldberg, M. ; Horwitz, N. ; et al.

Phys.Rev.Lett. 51 (1983) 634, 1983.

Inspire Record 190325 DOI 10.17182/hepdata.20490

Evidence is presented for a narrow meson resonance of mass 1970±5±5 MeV produced in continuum e+e− annihilations at s of 10.5 GeV, and decaying into a ϕ and a charged π.

1 data table

Table 1

CROSS SECTION OVER ALL F MOMENTA CALCULATED ASSUMING SPECTRUM BELOW 2.5 HAS SAME SHAPE AS D MESON PRODUCTION.

Production of Charmed Mesons in $e^+ e^-$ Annihilation at 10.5-{GeV}

The CLEO collaboration Avery, P. ; Bebek, C. ; Berkelman, Karl ; et al.

Phys.Rev.Lett. 51 (1983) 1139, 1983.

Inspire Record 191835 DOI 10.17182/hepdata.20524

A measurement is presented of the inclusive production of charged D* and neutral D mesons from nonresonant e+e− annihilation in the energy region near the ϒ(4S) resonance. The momentum distribution shows a large contribution at high momenta as expected for heavy quark production. Comparison of the spectrum with several phenomenological models is made. The relative yields of the D* and D mesons indicate that the charm cross section is dominated by the D* contribution.

2 data tables

Table 1

No description provided.

Table 2

No description provided.