Charm - Anticharm Asymmetries in High Energy Photoproduction

The E687 collaboration Frabetti, P.L. ; Cheung, H.W.K. ; Cumalat, John P. ; et al.
Phys.Lett.B 370 (1996) 222-232, 1996.
Inspire Record 415573 DOI 10.17182/hepdata.42320

We report measurements of charm particle production asymmetries from the Fermilab photoproduction experiment E687. An asymmetry in the rate of production of charm versus anticharm particles is expected to arise primarily from fragmentation effects. We observe statistically significant asymmetries in the photoproduction of D + , D ∗+ and D 0 mesons and find small (but statistically weak) asymmetries in the production of the D s + meson and the Λ c + baryon. Our inclusive photoproduction asymmetries are compared to predictions from nonperturbative models of charm quark fragmentation.

3 data tables

Production asymmetry. E-gamma = 200 GeV is mean energy. Only reactions for charm particle production are present in the table. SIG(C=ANTI-CHARM) denotes the reaction with anti-charm production.

Antiparticle/particle production ratio. E-gamma = 200 GeV is mean energy. Only reactions for charm particle production are present in the table. SIG(C=ANTI-CHARM) denotes the reaction with anti-charm production.

Production asymmetry for particles produced in association with a D*(2010)+-. E-gamma = 200 GeV is mean energy. Only reactions for charm particle production are present in the table.


Evidence of the Cabibbo Suppressed Decay $\Lambda_c^+ \to p K^- K^+$

The E687 collaboration Frabetti, P.L. ; Cheung, H.W.K. ; Cumalat, John P. ; et al.
Phys.Lett.B 314 (1993) 477-481, 1993.
Inspire Record 356600 DOI 10.17182/hepdata.42675

We report evidence for the Cabibbo-suppressed decay of the charm baryon Λ c + into the final state pK − K + . The analysis is performed on data collected by high energy photoproduction experiment E687 during the 1990–1991 Fermilab fixed target run. The branching ratio of the decay Λ c + → pK − K + relative to the non-suppressed Λ c + → pK − π + is measured to be BR( pK − K + / pK − π + ) = 0.096 ± 0.029 ± 0.010. The upper limit of the decay into pø relative to the inclusive pK − K + decay is measured to be BR( pø / pK − K + < 58% at the 90% confidence level.

2 data tables

Branching ratio of Cabibbo-suppressed and resolved modes.

No description provided.


Production and decay of the D(s1)+ (2536)

The CLEO collaboration Alexander, James P. ; Bebek, C. ; Berkelman, Karl ; et al.
Phys.Lett.B 303 (1993) 377-384, 1993.
Inspire Record 352823 DOI 10.17182/hepdata.47264

Using the CLEO-II detector at CESR, we have observed the D s 1 (2536) + in the decay modes D s1 + →D ∗0 K + and D ∗+ K S + , and measured its fragmentation and production ratios. Using the helicity angle distribution of the daugter D ∗0 , we obtain new evidence for the assignment of 1 + for the spin and parity of the D s 1 + . We also set upper limits on the decays D s1 + →D s ∗+ λ, D 0 K + and D + K s 0 .

2 data tables

No description provided.

No description provided.


Confirmation of the Existence of the Sigma(c)++ and Lambda(c)+ Charmed Baryons

Baltay, C. ; Caroumbalis, D. ; French, H. ; et al.
Phys.Rev.Lett. 42 (1979) 1721, 1979.
Inspire Record 140761 DOI 10.17182/hepdata.50280

In a broadband neutrino exposure of the Fermilab 15-ft bubble chamber, we observe the production of the Σc++(2426) charmed baryon followed by its decay to Λc+(2260) and π+. We find the mass of the Λc+ to be 2257±10 MeV and the m(Σc++)−m(Λc+) mass difference to be 168±3 MeV. Previously unseen two-body decay modes of the Λc+(2260) are observed.

1 data table

No description provided.