Observation of a dimuon resonance at 9.5-GeV in 400-GeV proton - nucleus collisions

The E288 collaboration Herb, S.W. ; Hom, D.C. ; Lederman, L.M. ; et al.
Phys.Rev.Lett. 39 (1977) 252-255, 1977.
Inspire Record 120368 DOI 10.17182/hepdata.42613

Dimuon production is studied in 400-GeV proton-nucleus collisions. A strong enhancement is observed at 9.5 GeV mass in a sample of 9000 dimuon events with a mass $m_{\mu^+\mu^-} \to$ 5 GeV.

1 data table

Two peaks were observed. Mass spectrum was fitted to one and two resonance hypothesis.


The Reactions K+ p --> Lambda x++ and K+ p --> anti-Lambda x++ at Incident Momenta of 8.2-GeV/c and 16.0-GeV/c

Chliapnikov, P.V. ; Ciapetti, G. ; Dunwoodie, W. ; et al.
Nucl.Phys.B 112 (1976) 1-51, 1976.
Inspire Record 109100 DOI 10.17182/hepdata.35646

Inclusive production of Λ and Λ in K + p interactions is studied at incident momenta of 8.2 and 16.0 GeV/ c . Cross sections and single-particle distributions are presented, the correlation between longitudinal and transverse momentum is investigated, and the dependence of average charge multiplicity on missing mass measured. For Λ production, early scaling is observed in the target fragmentation region when the data are presented in terms of ( M 2 - M th 2 )/ s and t , where M th is the threshold value of the missing mass M . Furthermore, a triple-Regge analysis in these variable yields an effective exchange trajectory which passes through the K, Q and L mesons. There is evidence for beam fragmentation in Λ and Λ production, but the contributions seem not to be dominant in the fragmentation region. Nevertheless, the parameter values in a triple-Regge description are estimated, and together with those for target fragmentation in Λ production, provide a complete description of the fragmentation contributions to the two reactions. Integration of the resultant distribution functions over the complete Chew-Low plot yields fragmentation cross sections increasing approximately as log s ; in addition the observed features of the x , p L and p T 2 projections and of the p L - p T correlation are well-described in the fragmentation regions. Central production contributions are isolated by subtracting the calculated fragmentation distributions

20 data tables

No description provided.

No description provided.

No description provided.

More…

Production of $\psi$ (3100) and $\psi^{\prime}$ (3700) in p-Be Collisions at 400 GeV

Snyder, H.D. ; Hom, D.C. ; Lederman, L.M. ; et al.
Phys.Rev.Lett. 36 (1976) 1415, 1976.
Inspire Record 108462 DOI 10.17182/hepdata.21117

We report preliminary results on the production of electron-positron pairs in the mass range 2.5 to 4 GeV in 400-GeV p-Be interactions. Production cross sections of the ψ(3100) near x=0 as a function of pt, x, and the decay angle are presented and implications of these new data for single direct leptons are discussed. A ψ′(3700) signal is observed at a level corresponding to σ(ψ′)σ(ψ)=(10±3)%.

1 data table

No description provided.