Evidence for a narrow dip structure at 1.9 GeV/c2^2 in 3π+3π−3\pi^+ 3\pi^- diffractive photoproduction

A narrow dip structure has been observed at 1.9 GeV/c$^2$ in a study of diffractive photoproduction of the $~3\pi^+3\pi^-$ final state performed by the Fermilab experiment E687.Comment: The data of Figure 6 can be obtained by downloading the raw data file e687_6pi.txt. v5 (2nov2018): added Fig. 7, the 6 pion energy distribution as requested by a reade

Study of charged hadronic five-body decays of the D+ and Ds+ mesons

Charged hadronic five-body decays of D+ and Ds+ mesons have been studied in the E687 photoproduction experiment at Fermilab. We report the first compelling evidence of the decay mode D+, Ds+ \u2192 pi 12pi 12pi+pi+pi+ and the measurements of the decays D+ \u2192 K 12pi 12pi+pi+pi+, Ds+ \u2192 K 12K+pi 12pi+pi+ and Ds+ \u2192 phi pi 12pi+pi+. An analysis of the D+ \u2192 K 12pi 12pi+pi+pi+ resonance structure is also presente

Observation and mass measurement of Omega(c)0 -> Sigma+ K- K- pi+

We present evidence for the Omega(c)0 in a new decay mode Omega(c)0 -> Sigma+ K- K- pi+, for which we find 42.5 +- 8.8 events with a mass of 2699.9+-1.5+-2.5 MeV/c2. The data are from Fermilab high energy photoproduction experiment E68

Observation of an excited state of the Lambda(c)+ baryon

An observation of an excited Lambda(c)+* baryon decaying to Lambda(c)+pi+pi-, with Lambda(c)+\u2192pK-pi+, is presented. We reconstruct 39.7+-8.7 Lambda(c)+* baryons with a mass of 340.4+-0.6+-0.3 MeV/c2 above the Lambda(c)+ mass. The upper limit on the resonant branching ratio is B(Lambda(c)+*\u2192Sigma(c)pi\ub1)/B(Lambda(c)+*\u2192Lambda(c)+ pi+pi-)<36% at the 90% confidence level

Measurment of the masses and widths of L=1 charmed mesons

We report the measurement of masses and widths of the following L=1 charm mesons by the E687 Collaboration at Fermilab: a D(2)*0 state of mass (width) 2453+-3+-2 (25+-10+-5) MeV/c2 decaying to D+pi-, a D(2)*+ state of mass (width) 2453+-3+-2 (23+-9+-5) MeV/c2 decaying to D0pi+, a D(1)0 state of mass (width) 2422+-2+-2 (15+-8+-4) MeV/c2 decaying to D*+pi-, and a D(s1)+ state of mass 2535.0+-0.6+-1.0 MeV/c2 and width <3.2 MeV/c2 at 90% confidence level, decaying to D*+Ks0 and D(*0)K+