Measurement of orbitally excitedDmesons at CDF II

Abstract

Properties of the X(3872)Guillelmo IntroductionThe mesons containing one heavy quark are a useful laboratory to test QCD models. In the limit of heavy quark mass m Q → ∞, heavy mesons' properties are governed by the dynamics of the light quark. As such, these states become "hydrogen atoms" of hadron physics. In this Heavy Quark Symmetry approach (see References [1,2,3,4,5]) the quantum numbers of the heavy and light quarks are separately conserved by the strong interaction. For the charmed D-mesons the heavy charmed quark spin, s Q , couples with the light quark momentum j q = s q + L, where s q is the spin of the light quark and L is its angular momentum. Hence for P -wave (L = 1) mesons we obtain two j q = 3/2 + states, the J P = 2 + , 1 + states, and two j q = 1/2 + states, the J P = 0 + , 1 + states. In the Heavy Quark Symmetry limit, conservation of parity and j q requires that the strong decaysand again via D-wave. D 1 (J P = 1 + , j q = 1/2 + ) converts only into D * (J P = 1 − ) emitting a pseudoscalar π in S-wave, while D * 0 (J P = 0 + , j q = 1/2 + ) decays only to D(J P = 0 − )π(J P = 0 − ) and only in S-wave. States decaying via S-wave are expected to be broad while those decaying via D-wave are expected to be narrow.The first observation of excited charmed mesons was made by the ARGUS Collaboration (see References [6,7,8,9,10]) and immediately confirmed by CLEO [11] and the Tagged Photon Spectrometer (FNAL) [12] Collaborations. The states have also been studied at LEP [13,14,15]. A high statistics analysis has been done with the CLEO-II detector [16,17]. The most recent measurements by the CLEO-II [18], BELLE [19], and FOCUS [20,21] experiments have improved the previous ones and extracted the contributions of broad D 1 and D * 0 states.

Masses of excited heavy baryons in the relativistic quark–diquark picture

“…The obtained results were found to be in good agreement with experimental data [2]. Moreover, the predicted masses of the Ω * c and Σ b , Σ * b proved to be very close to the recently measured ones [3,4]. This gives us additional confidence in the reliability of the used quark-diquark approximation within our model.…”

“…The calculated values of the ground state and excited baryon masses are given in Tables III-VII in comparison with available experimental data [2,4,22,23,24,25,26]. In the first two columns we put the baryon quantum numbers and the state of the heavyquark-light-diquark bound system (in usual notations nL), while in the rest columns our predictions for the masses and experimental data are shown.…”

Bounding effective parameters in the chiral Lagrangian for excited heavy mesons

“…MeV) and with a recent measurement by CDF Collaboration [14], the width of D * 0 2 is larger than the PDG value (Γ(D 0 1 ) = 23 ± 5 MeV), while it is consistent with a Focus measurement: Γ(D * 0 2 ) = 38.7 ± 5.3 ± 2.9 MeV [5] and a CDF measurement: Γ(D * 0 2 ) = 49.2 ± 2.1 ± 1.2 MeV [14]. We use h = −0.56 [15].…”

Search for Pentaquarks with CLAS

“…Perhaps most importantly, several highenergy accelerator laboratories have been unable to observe any corroborating signal, even in cases with high statistical precision [15,16,17,18,19,20,21,22,23,24,25,26,27]. Perhaps most importantly, several highenergy accelerator laboratories have been unable to observe any corroborating signal, even in cases with high statistical precision [15,16,17,18,19,20,21,22,23,24,25,26,27].…”