We have searched for exclusive production of exotic charmonia in the reaction μ+N → μ+( J/ψπ+π−)π±N using COMPASS data collected with incoming muons of 160 GeV/c and 200 GeV/c momentum. In the J/ψπ+π− mass distribution we observe a signal with a statistical significance of 4.1 σ. Its mass and width are consistent with those of the X(3872). The shape of the π+π− mass distribution from the observed decay into J/ψπ+π− shows disagreement with previous observations for X(3872). The observed signal may be interpreted as a possible evidence of a new charmonium state. It could be associated with a neutral partner of X(3872) with C = −1 predicted by a tetraquark model. The product of cross section and branching fraction of the decay of the observed state into J/ψπ+π− is determined to be 71±28(stat)±39(syst) pb
Titolo: | Search for muoproduction of X (3872) at COMPASS and indication of a new state X˜(3872) |
Autori: | |
Data di pubblicazione: | 2018 |
Stato di pubblicazione: | Pubblicato |
Rivista: | |
Abstract: | We have searched for exclusive production of exotic charmonia in the reaction μ+N → μ+( J/ψπ+π−)π±N using COMPASS data collected with incoming muons of 160 GeV/c and 200 GeV/c momentum. In the J/ψπ+π− mass distribution we observe a signal with a statistical significance of 4.1 σ. Its mass and width are consistent with those of the X(3872). The shape of the π+π− mass distribution from the observed decay into J/ψπ+π− shows disagreement with previous observations for X(3872). The observed signal may be interpreted as a possible evidence of a new charmonium state. It could be associated with a neutral partner of X(3872) with C = −1 predicted by a tetraquark model. The product of cross section and branching fraction of the decay of the observed state into J/ψπ+π− is determined to be 71±28(stat)±39(syst) pb |
Handle: | http://hdl.handle.net/11368/2927771 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.physletb.2018.07.008 |
URL: | https://www.sciencedirect.com/science/article/pii/S037026931830546X |
Appare nelle tipologie: | 1.1 Articolo in Rivista |
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