Near-threshold DD¯$$ \mathrm{D}\overline{\mathrm{D}} $$ spectroscopy and observation of a new charmonium state
Abstract Using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector between 2011 and 2018, a new narrow charmonium state, the X(3842) resonance, is observed in the decay modes X3842→D0D¯0$$ \mathrm{X}(3842)\to {D}^0{\ove...
| Main Authors: | , , , , , , , , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer Berlin Heidelberg
2021
|
| Online Access: | https://hdl.handle.net/1721.1/131683 |
| Summary: | Abstract
Using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector between 2011 and 2018, a new narrow charmonium state, the X(3842) resonance, is observed in the decay modes X3842→D0D¯0$$ \mathrm{X}(3842)\to {D}^0{\overline{D}}^0 $$ and X(3842) → D+D−. The mass and the natural width of this state are measured to be
m
X
3842
=
3842.71
±
0.16
±
0.12
M
e
V
/
c
2
,
Γ
X
3842
=
2.79
±
0.51
±
0.35
M
e
V
,
$$ \begin{array}{l}{m}_{X(3842)}=3842.71\pm 0.16\pm 0.12\ MeV/{c}^2,\hfill \\ {}{\varGamma}_{X(3842)}=2.79\pm 0.51\pm 0.35\ MeV,\hfill \end{array} $$
where the first uncertainty is statistical and the second is systematic. The observed mass and narrow natural width suggest the interpretation of the new state as the unobserved (spin-3 ψ3 13D3) charmonium state.
In addition, prompt hadroproduction of the ψ(3770) and χ2(3930) states is observed for the first time, and the parameters of these states are measured to be
m
ψ
3770
=
3778.1
±
0.7
±
0.6
M
e
V
/
c
2
,
m
χ
2
3930
=
3921.9
±
0.6
±
0.2
M
e
V
/
c
2
,
Γ
χ
2
3930
=
36.6
±
1.9
±
0.9
M
e
V
,
$$ \begin{array}{l}{m}_{\psi (3770)}=3778.1\pm 0.7\pm 0.6\ MeV/{c}^2,\hfill \\ {}{m}_{\chi_2(3930)}=3921.9\pm 0.6\pm 0.2\ MeV/{c}^2,\hfill \\ {}{\varGamma}_{\chi_2(3930)}=36.6 \pm 1.9 \pm 0.9\ MeV,\hfill \end{array} $$
where the first uncertainty is statistical and the second is systematic. |
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