HEPData Search

Showing 6 of 46 results

Coupled channel analysis of anti-p p annihilation into pi0 pi0 pi0, pi0 eta eta and pi0 pi0 eta

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Baker, C.A. ; et al.

Phys.Lett.B 355 (1995) 425-432, 1995.

Inspire Record 406130 DOI 10.17182/hepdata.28523

We confirm the existence of the two I G ( J PC ) = 0 + (0 ++ ) resonances f 0 (1370) and f 0 (1500) reported by us in earlier analyses. The analysis presented here couples the final states π 0 π 0 π 0 , π 0 π 0 η and π 0 ηη of p p annihilation at rest. It is based on a 3 × 3 K -matrix. We find masses and widths of M = (1390±30) MeV, Γ = (380±80) MeV; and M = (1500±10) MeV, Γ = (154 ± 30) MeV, respectively. The product branching ratios for the production and decay into π 0 π 0 and ηη of the f 0 (1500) are (1.27 ± 0.33) · 10 −3 and (0.60 ± 0.17) · 10 −3 , respectively.

1 data table

Table 1

No description provided.

E decay to eta pi pi in anti-p p annihilation at rest

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Baker, C.A. ; et al.

Phys.Lett.B 358 (1995) 389-398, 1995.

Inspire Record 407517 DOI 10.17182/hepdata.28511

We have observed the ηπ + π − and ηπ 0 π 0 decay modes of the E meson in p p annihilation at rest into π + π − π 0 π 0 η . The mass and width of the E meson are 1409 ± 3 and 86 ± 10 MeV. The production and decay branching ratio is B( p p → Eππ)B(E → ηππ) = (3.3 ± 1.0) × 10 −3 . With a spin-parity analysis we determine that J P = 0 − . The observation of the ηπ 0 π 0 decay mode establishes that E is isoscalar ( C = +1). We find that E decays to η ( ππ ) s (where ( ππ ) s is an S-wave dipion) and πa 0 (980)(→ πη ) with a relative branching ratio of (78 ± 16) %. Using the K K π production and decay branching ratio measured earlier we determine that B[E → K K π] B[E → ηππ] = 0.61 ± 0.19 . A comparison with observations in radiative J Ψ decays suggests that E and ι η (1416) are identical.

1 data table

Table 1

Unobserved channels (E --> ETA 2PI0)2PI0 and (E --> ETA PI+ PI-)PI+PI- was taken into account.

Observation of radiative anti-p p annihilation into a phi meson

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Augustin, I. ; et al.

Phys.Lett.B 346 (1995) 363-370, 1995.

Inspire Record 401140 DOI 10.17182/hepdata.28709

The annihilation p p → Φγ has been investigated with the Crystal Barrel detector at LEAR for antiprotons stopped in liquid hydrogen. The observed branching ratio BR ( p p → Φγ = (1.7 ± 0.4) · 10 −5 is almost two orders of magnitude higher than expected from the OZI-rule. As a by-product, the branching ratios BR ( p p → K L K S ) = (9.0 ± 0.6) · 10 −4 and BR ( p p → Φπ 0 ) = (5.5 ± 0.7) · 10 −4 have been measured.

1 data table

Table 1

No description provided.

RESULTS FOR NEUTRAL TO CHARGED CURRENT CROSS-SECTION RATIOS FROM neutrino AND anti-neutrino NUCLEUS INTERACTIONS BELOW 30-GeV

Ammosov, V.V. ; Baranov, D.S. ; Ermolaev, V.I. ; et al.

Z.Phys.C 30 (1986) 569, 1986.

Inspire Record 215972 DOI 10.17182/hepdata.15876

Using the freon filled bubble chamber SKAT in the (anti)neutrino wide band beam of the Serpukhov accelerator we determine the neutral to charged current cross section ratios for neutrinos and antineutrinos below 30GeV. From these ratios we calculate in leading order a mixing parameter of the standard model of Θw=0.215±0.029.

3 data tables

Table 1

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

Table 2

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

Table 3

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