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

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

Measurement of the form factors for the decay D(s)+ → phi mu+ nu

The fermilab high-energy photoproduction experiment E687 provides a sample of approximately 90 events of the decay mode D(s)+\u2192 phi mu+ nu. The ratios of the form factors governing the decay are measured to be Rv=1.8+-0.9+-0.2 and R2= 1.1+-0.8+-0.1, implying a polarization of G1/Gt=1.0+-0.5+-0.1 for the electron decay, consistent with our measurement of the form factor for the decay D+->anti(K0*) mu+ nu

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+

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

Search for the decay of D+ and Ds+ mesons to three charged kaons

We report the results of a search for the doubly Cabibbo suppressed decays D+ \u2192 K+K 12K+ and D+ \u2192 phi K+, and the singly Cabibbo suppressed decays Ds+ \u2192 K+K 12K+ and Ds+ \u2192 phi K+. Our measurements are all consistent with zero branching ratio, and we set 90% confidence level upper limits on the relative D+ branching ratios: BR(phi K+)/BR(phi pi+) < 0.021, BR(K+K-K+)/BR(phi pi+) < 0.025, and BR(K+K-K+)/BR(K-pi+pi+) < 0.0016, and the relative Ds+ branching ratios: BR(phi K+) / BR(phi pi+) < 0.013 and BR(K+K-K+)/BR(phi pi+) < 0.016. The data were accumulated by the Fermilab high energy photoproduction experiment E687

A MEASUREMENT OF GAMMA(DS+->PHI MU+NU) / GAMMA(DS+->PHI-PI+).

Fermilab high-energy photoproduction experiment E687 measures a branching ratio of Gamma (DS+ \u2192 phi mu+nu) /Gamma (DS+ \u2192 phi mu+) = 0.58 \ub1 0.17 (stat) \ub1 0.07 (sys). This branching ratio is combined with theoretical inputs to obtain a new measurement of the DS+ absolute branching ratio of Gamma (DS+ \u2192 phi mu+) / Gamma(DS+ \u2192 all) = 0.031 \ub1 0.009 (stat 0.005 (sys) \ub1 0.004 (theoretical)