Can the X(3872) be a 1^{++} four-quark state?
| dc.creator | Matheus, R. D. | |
| dc.creator | Narison, S. | |
| dc.creator | Nielsen, M. | |
| dc.creator | Richard, J. M. | |
| dc.date | 2006-08-28 | |
| dc.date | 2006-12-08 | |
| dc.date.accessioned | 2026-07-07T11:05:36Z | |
| dc.date.available | 2026-07-07T11:05:36Z | |
| dc.description | We use QCD spectral sum rules to test the nature of the meson X(3872), assumed to be an exotic four-quark (c\bar{c}q\bar{q}) state with J^{PC}=1^{++}. For definiteness, we work with the current proposed recently by Maiani et al [1], at leading order in α_s, consider the contributions of higher dimension condensates and keep terms which are linear in the light quark mass m_q. We find M_X=(3925+- 127) MeV which is compatible, within the errors, with he experimental candidate X(3872), while the SU(3) breaking-terms lead to an unusual mass-splitting M_{X^{s}}-M_X=- (61+-30) MeV. The mass-difference between the neutral states due to isospin violation of about (2.6-3.9) MeV is much smaller than the value (8+-3) MeV proposed in [1]. For the b-quark, we predict M_{X_b}= (10144+-106) MeV for the X_b(b\bar{b}q \bar{q}), which is much below the {\bar B}B* threshold in contrast to the {\bar B}B* molecule prediction [2], and for the X_b^s(b\bar{b}s \bar{s}), a mass-splitting M_{X^s_{b}}-M_{X_b}=-(121+-182) MeV. Our analysis also indicates that the mass-splitting between the ground state and the radial excitation of about (225~250) MeV is much smaller than in the case of ordinary mesons and is (within the errors) flavour-independent. We also extract the decay constants, analogous to f_π, of such mesons, which are useful for further studies of their leptonic and hadronic decay widths. The uncertainties of our estimates are mainly due to the ones from the c and b quark masses. | |
| dc.description | 16 pages, 10 figures. Version to appear in Phys. Rev. D | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0608297 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0608297 | |
| dc.identifier | Phys.Rev.D75:014005,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.75.014005 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/189252 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | High Energy Physics - Experiment | |
| dc.subject | High Energy Physics - Lattice | |
| dc.subject | Nuclear Theory | |
| dc.title | Can the X(3872) be a 1^{++} four-quark state? | |
| dc.type | text |