TheX(3872) as a charmonium state plus an extra component due to continuum coupling effects

Abstract

Abstract. We discuss the results of an unquenched quark model (UQM) calculation of the self energy corrections to charmonium spectrum due to the coupling to the meson-meson continuum. In our approach, the effects of quark-antiquark pairs are introduced explicitly into the QM through a 3 P 0 quark-antiquark pair-creation mechanism. Our results are fitted to the experimental data, so that the sum of the bare and self energies gives the values of the physical masses of the states of interest. Our results for the charmonium spectrum are used to discuss the nature of the X(3872) resonance.

Charmonium spectrum with a Dirac potential model in the momentum space

“…The semirelativistic calculations in [30,93], that employ a vector and a scalar interaction, obtain a mass of 3912 MeV for the 2 3 P 1 state. The UQM obtains a mass value around 3908 MeV [41,42,70,95]. A calculation in the coordinate space with a screened potential has also given a good result of 3901 MeV [64].…”

Symmetry in Particle Physics

“…The lattice study [97] found an explanation for X(3872) in both the molecular and tetraquark scenario. An important group of analyses focused on charmonium [98][99][100] or mixed charmonium [101][102][103][104] explanations. Further arguments in favor of a charmonium structure followed from the Flatté analysis performed in [105], and both molecular and charmonium hypotheses were discussed in [106].…”

“…Both CDF and D0 collaborations performed the full set of measurements in both +jets and dilepton channels with full Run II statistics [72,[97][98][99][100][101][102][103]. Moreover, there was performed the combination of the CDF and D0 measurements [49].…”

“…The forward-backward asymmetry as a function of |Δy| (left) and m tt (right) with a best-fit line superimposed. The shaded region represents the theoretical uncertainty on the slope of the prediction [97].D0 measured the t t asymmetry in the +jets channel using full Run II statistics of 9.7 fb −1[102]. The inclusive asymmetry is measured A t t FB = (10.6 ± 3.0)%.…”

$χ_{c1}(2p)$: an overshadowed charmoniumlike resonance

“…In this approach, quarkoniumlike mesons with quantum numbers J P C are described through the solutions of a multichannel Schrödinger equation for Q Q and open-flavor meson-meson components, where the form of the potential incorporates string breaking as observed in lattice QCD. This is a major difference with quantum mechanical phenomenological analyses based on the same degrees of freedom [8][9][10][11][12][13][14][15][16][17], but where the Q Q-meson-meson interaction lacks a connection to QCD.…”