Towards an Understanding of the New Charm and Charm-Strange Mesons

The observation of the D_{sJ}^*(2317), D_{sJ}(2460), and SELEX D^*_{sJ}(2632) states with properties differing considerably from what was expected has led to a renewed interest in hadron spectroscopy. In addition to these states, non-strange partners of the D_{sJ} states have also been observed. Understanding the D_0^* and D_1' states can provide important insights into the D_{sJ} states. In this contribution I examine quark model predictions for the D_0^* and D_1' states and discuss experimental measurements that can shed light on them. I find that these states are well described as the broad, j=1/2 non-strange charmed P-wave mesons. In the latter part of this writeup I discuss the c bar{s} possibilities for the SELEX D^*_{sJ}(2632) and measurements that can shed light on it.Comment: Talk presented at the 1st Meeting of the APS Topical Group on Hadronic Physics (Fermilab, Oct 24-26, 2004). 4 pages uses jpcon

Possible Interpretations of DsJ+(2632)D_{sJ}^+(2632) If It Really Exists

We analyze various possible interpretations of the narrow state $D_{sJ}^+(2632)$ observed by SELEX Collaboration recently, which lies above threshold and has abnormal decay pattern. These interpretations include: (1) several versions of tetraquarks; (2) conventional $c\bar s$ meson such as the first radial excitation of $D_s(2112)$ with abnormally large SU(3) symmetry breaking; (3) conventional $c\bar s$ meson with abnormally large $\eta_1$ coupling; (4) heavy hybrid meson. We discuss the physical implications of each interpretation. For example, if the existence of $D_{sJ}^+(2632)$ is confirmed as the first radial excitation of $D_s(2112)$ by other experiments, it will be helpful to look for (1) its SU(3) flavor partners $D_{J}^{0,+}(2530)$; (2) its B-meson analogues $B_{J}^{0,+}(5840), B_{sJ}^+(5940)$; (3) S-wave two pion decay modes

Nuclear dependence of charm production

Using data taken by SELEX during the 1996-1997 fixed target run at Fermilab, we study the production of charmed hadrons on copper and carbon targets with Sigma(-), p, pi(-), and pi(+) beams. Parametrizing the dependence of the inclusive production cross section on the atomic number A as A(alpha), we determine alpha for D(+), D(0), D(s)(+), D(+)(2010), Lambda(+)(c), and their respective anti-particles, as a function of their transverse momentum p(t) and scaled longitudinal momentum x(F). Within our statistics there is no dependence of alpha on x(F) for any charm species for the interval 0.1 < x(F) < 1.0. The average value of alpha for charm production by pion beams is alpha(meson) = 0.850 +/- 0.028. This is somewhat larger than the corresponding average alpha(baryon) = 0.755 +/- 0.016 for charm production by baryon beams (Sigma(-), p).Bundesministeriums für Bildung und Forschung (BMBF)Bundesministerium fur Bildung, Wissenschaft, Forschung und Technologie (BMBF)Consejo Nacional de Ciencia y Tecnología (CONACYT) - MéxicoConsejo Nacional de Ciencia y Tecnologia (CONACyT)CNPq Conselho Nacional de Desenvolvimento Cientifico e TecnologicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fondo de Apoyo a la Investigacion (UASLP)Fondo de Apoyo a la Investigacion (UASLP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Israel Academy of Sciences and HumanitiesIsrael Academy of Sciences and HumanitiesIstituto Nazionale di Fisica Nucleare (INFN)Istituto Nazionale di Fisica Nucleare (INFN)International Science Foundation (ISF)International Science Foundation (ISF)National Science Foundation (NSF)[9602178]U.S. National Science Foundation (NSF)NATONATO[CR6.941058-1360/94]Russian Academy of ScienceRussian Academy of SciencesRussian Ministry of Science and TechnologyRussian Ministry of Science and TechnologyRussian Foundation for Basic ResearchRussian Foundation for Basic Research[08-02-00657]Secretaria de Educacion Publica (Mexico)[2003-24-001-026]Secretaria de Educacion Publica (Mexico)Turkish Scientific and Technological Research Board (TUBITAK)Turkish Scientific and Technological Research Board (TUBITAK)U.S. Department of Energy (DOE)[DE-FG02-91ER40664]U.S. Department of Energy (DOE)U.S. Department of Energy (DOE)[DE-AC02-76CHO3000]U.S. Department of Energy (DOE

Observation of the Cabibbo-suppressed decay Xi(+)(c) -> pK(-)pi(+)

We report the first observation of the Cabibbo-suppressed charm baryon decay Xi(c)(+) --> pK(-)pi(+) We observe 150 +/- 22 +/- 5 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma(-) beam. The branching fractions of the decay relative to the Cabibbo-favored Xi(c)(+) --> Sigma(+)K(-)pi(+) and Xi(c)(+) --> Xi(-)pi(+)pi(+) are measured to be B(Xi(c)(+) --> pK(-)pi(+))/B(Xi(c)(+) --> Sigma(+)K(-)pi(+)) = 0.22 +/- 0.06 +/- 0.03 and B(Xi(c)(+) --> pK(-)pi(+))/B(Xi(c)(+) --> Xi(-)pi(+)pi(+)) = 0.20 +/- 0.04 +/- 0.02, respectively