Study of the reactions ?? p?K 0 ? and ?? p?K 0?0 at 3.95 GeV/c

Abstract

Treatment of N,N-diacetyl-o-toluidine with N-bromosuccinilllide followed by hydrolysis of the intermediate dibromo compound gave o-acetanlinobenzalde-hyde. The reaction was applied successfully to N,N-diacetyl-p-toluidine, N,N-diacetyl-4-chloro-o-toluidine, 2,4-bis(diacetamino)toluene, and 4-acetosy-N,N-diacetyl-o-toluidine. Both o-and p-acetaminobenzaldehyde were required for synthetic work in this laboratory. These compoullds have been prepared in the usual way b y the acetylation (6, 7) of o-and p-aminobenzaldehyde. However, the methods described in the literature for the preparation of o-aminobenzaldehyde by the reduction of o-nitrobenzaldehyde with ferrous sulplzate and ammonia (15) and for p-aminobenzaldehyde by the action of sodium polysulphide upon p-nitrotoluene (3) are tedious, and the products must be used immediately in order t o avoid self-condensation. A direct preparation of o-and p-acetaminobenzaldehyde was suggested b y the hydrolysis of N,N-diacetyl-p-toluidine (16) using aqueous sodium carbon-I ate which gave a quantitative yield of p-acetotoluidide, and also by the work of Brown and Newbold (2) who used N-bromosuccinimide to oxidize 4-I chloromethylmeco~~in(I) t o 3-formylopianic acid (11). I I CH?CI CHO I I1 We found that treatment of N,N-diacetyl-p-toluidine with two moles of N-bromosucciilimide in carbon tetrachloride, followed by aqueous sodium car-bonate hydrolysis without isolatioil of the intermediate bromo compound, gave p-acetaminobenzaldehyde in 70y0 yield. Similarly, N,N-diacetyl-o-toluidine (16) gave o-acetaminobenzaldehyde in 66% yield. The reaction was iilvestigated further with respect t o certain 4-substituted N,N-diacetyl-o-toluidiiles prepared by proloilged refluxing of the toluidine or its acetyl derivative in acetic anhydride. N,N-Diacet~l-4-chloro-o-toluidine, 2,4-bis(diacetamino)toluene, and 4-acetoxy-N,N-diacet~l-o-toluidine when 1 'Manz~script received Az~gust 29, 1955. Cotztrzbutzon from tibe

Scalar mesons and multichannel amplitudes

“…and use E max ≈ 1.1 GeV as a good representation of the upper experimental limit of the K 0 S K 0 S effective energy (see [21] for a discussion of experimental uncertainties). Experimental values of η av obtained in [21,22,23] are equal to 0.67±0.09, 0.78±0.03 and 0.81 +0.09 −0.04 respectively. Our calculations give lower values: 0.487, 0.496 and 0.494 for the solutions A, B and E, respectively.…”

Comparison of 20 exclusive reactions at larget

“…We have also compared the A results with lower energy data, using s-a scaling, although the lower energy results are not in the scaling region. Loverre et al[18] measuredT -p +A K O at 3.95 GeV/c and Bachman et al [19] at 3.15 GeV/c, both at 90' c.m. The Loverre result scales to 22% 7 nb/(GeV/c)' and the Bachman result scales to 19% 8 nb/(GeV/c)'; our upper limit is 5 nb/(GeV/c)'.…”

The positive-parity mesons

“…This analysis is model-dependent, but there is ample evidence for the dominance of OPEA, as demonstrated by the EMSA group itself and also by Gorlich et a1 (1980) and Loverre et a1 (1980). These last authors have compared the production of the K:K: system for D and S waves at various incident momenta (4, 6, 7 and 9 GeV/c).…”