Search results for "Charm"
showing 10 items of 390 documents
Detecting the long-distance structure of the $$X(3872)$$ X ( 3872 )
2014
We study the X(3872)-->D^0 \bar D^0 \pi^0 decay within a D \bar D^* molecular picture for the X(3872) state. This decay mode is more sensitive to the long-distance structure of the X(3872) resonance than its J/\psi\pi\pi and J/\psi3\pi decays, which are mainly controlled by the details of the X(3872) wave function at short distances. We show that the D^0 \bar D^0 final state interaction can be important, and that a precise measurement of this partial decay width can provide valuable information on the interaction strength between the D^{(*)} \bar D^{(*)} charm mesons.
Exclusive non-leptonic charm baryon decays
1992
We present a spectator quark model calculation of the Cabibbo-enhanced non-leptonic decays of the lowest lying charm baryons Λc, Ξc and Ωc decaying into non-charm ground state baryons and mesons. We employ covariant quark model wave functions to describe the ground state baryons and mesons. They are obtained by boosting rest frame wave functions to equal velocity frames. The non-leptonic decay amplitudes are then obtained in terms of two wave function overlap parameters which we fit to the experimental data. We discuss general features of the flavour and helicity composition of the final states in the quark model approach. We emphasize thatW-exchange contributions are of crucial importance …
Semi-leptonic charm baryon decays in the relativistic spectator quark model
1991
We calculate the exclusive semi-leptonic charm baryon decays of the lowest lying charm baryon states into the ground state strangeness baryons using the covariant spectator quark model approach. We present results on rates,q 2- andE l -spectra as well as on the angular decay distribution in the cascade decay $$\Omega _c \to \Omega ( \to \Xi \pi ,\Lambda {\rm K})$$ .
J/ψSuppression at Forward Rapidity in Pb-Pb Collisions atsNN=2.76 TeV
2012
The ALICE experiment has measured the inclusive J/psi production in Pb-Pb collisions at root s(NN) = 2.76 TeV down to zero transverse momentum in the rapidity range 2.5 < y < 4. A suppression of the inclusive J/psi yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%-80% most central collisions, is 0.545 +/- 0.032(stat) +/- 0.083dsyst_ and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/psi production from charm quarks in…
The Barrel DIRC of PANDA
2012
Cooled antiproton beams of unprecedented intensities in the momentum range of 1.5-15 GeV/c will be used for the PANDA experiment at FAIR to perform high precision experiments in the charmed quark sector. The PANDA detector will investigate antiproton annihilations with beams in the momentum range of 1.5 GeV/c to 15 GeV/c on a fixed target. An almost 4π acceptance double spectrometer is divided in a forward spectrometer and a target spectrometer. The charged particle identification in the latter is performed by ring imaging Cherenkov counters employing the DIRC principle.
Traces of the hidden-charm S=−1 pentaquark in the Λb→J/ΨηΛ decay
2017
The hidden charm pentaquark state Pc (4450), observed recently by the LHCb collaboration in the Λb →J/ψK − p decay, may be of molecular nature, as advocated by some unitary approaches that also predict pentaquark partners in the strangeness S=−1 sector. In this work we argue that a hidden-charm strange pentaquark could also be seen in the decay of theΛb , but through the J/ψη Λ decay mode, by studying the invariant mass spectrum of J/ψ Λ pairs.In our model we assume a standard weak decay topology, then incorporate the hadronization process and final state interaction effects, and we find that the J/ψη Λ final state is populated with the strength similar to that of the J/ψK− p . We have stud…
QCD duality and the mass of the Charm Quark
2001
The mass of the charm quark is analyzed in the context of QCD finite energy sum rules using recent BESII e+e- annihilation data and a large momentum expansion of the QCD correlator which incorporates terms to order (alpha_s)^2 (m_c^2/q^2)^6. Using various versions of duality, we obtain the consistent result m_c(m_c)=(1.37 +- 0.09)GeV. Our result is quite independent of the ones based on the inverse moment analysis.
Prediction of hidden charm strange molecular baryon states with heavy quark spin symmetry
2019
We have studied the meson-baryon $S-$wave interaction, using coupled channels, in the isoscalar hidden-charm strange sector and $J^P = 1/2^-,3/2^-$ and $5/2^-$. We impose constraints of heavy quark spin symmetry in the interaction and obtain the non vanishing matrix elements from an extension of the local hidden gauge approach to the charm sector. The ultraviolet divergences are renormalized using the same meson-baryon-loops regulator previously employed in the non-strange hidden charm sector, where a good reproduction of the properties of the newly discovered pentaquark states is obtained. We obtain five states of $1/2^-$, four of $3/2^-$ and one of $5/2^-$, which could be compared in the …
Charm and bottom baryon decays in the Bethe-Salpeter approach: Heavy to heavy semileptonic transitions
1998
Charm and bottom baryons and mesons are studied within the framework of a relativistically covariant 3D reduction of the Bethe-Salpeter equation. We carry out an analysis of semileptonic decays of heavy hadrons within this framework using explicit oscillator-type wave functions where we calculate Isgur-Wise functions, decay rates and asymmetry parameters. Within this model we also study the effect of interactions between the light quarks inside the heavy baryon and how they affect the values of the computed heavy baryon observables. We also elaborate on the role of relativistic effects in the calculation of the heavy baryon Isgur-Wise function.
Magnetic moments of heavy baryons
2000
6 páginas, 2 figuras, 4 tablas.-- PACS number(s): 12.39.Fe, 12.39.Hg, 14.20.Lq, 14.20.Mr