cern.ch

Study of $D^{(*)+}_{sJ}$ mesons decaying to $D^{*+} K^0_{\rm S}$ and $D^{*0} K^+$ final states

[to restricted-access page]

Information

Tools

Abstract

A search is performed for $D^{(*)+}_{sJ}$ mesons in the reactions $pp \to D^{*+} K^0_{\rm S} X$ and $pp \to D^{*0} K^+ X$ using data collected at centre-of-mass energies of 7 and 8 TeV with the LHCb detector. For the $D^{*+} K^0_{\rm S}$ final state, the decays $D^{*+} \to D^0 \pi^+$ with $D^0 \to K^- \pi^+$ and $D^0 \to K^- \pi^+ \pi^+ \pi^-$ are used. For $D^{*0} K^+$, the decay $D^{*0} \to D^0 \pi^0$ with $D^0 \to K^- \pi^+$ is used. A prominent $D_{s1}(2536)^+$ signal is observed in both $D^{*+} K^0_{\rm S}$ and $D^{*0} K^+$ final states. The resonances $D^*_{s1}(2700)^+$ and $D^*_{s3}(2860)^+$ are also observed, yielding information on their properties, including spin-parity assignments. The decay $D^*_{s2}(2573)^+ \to D^{*+} K^0_{\rm S}$ is observed for the first time, at a significance of 6.9 $\sigma$, and its branching fraction relative to the $D^*_{s2}(2573)^+ \to D^+ K^0_{\rm S}$ decay mode is measured.

Figures and captions

Distributions of $ D ^0 \pi ^+ $ invariant mass for (a) $ D ^0 \rightarrow K ^- \pi ^+ $ and (b) $ D ^0 \rightarrow K ^- \pi ^+ \pi ^+ \pi ^- $ . $\pi ^+ \pi ^- $ mass spectrum for (c) long and (d) downstream $ K ^0_{\mathrm{ \scriptscriptstyle S}}$ . The full (red) lines describe the fitting function. The dashed lines show the background contributions and the vertical dotted lines indicate the signal regions.

 fig1a.pdf [20 KiB]
HiDef png [219 KiB]
Thumbnail [179 KiB]
*.C file
fig1a.pdf
fig1b.pdf [20 KiB]
HiDef png [212 KiB]
Thumbnail [173 KiB]
*.C file
fig1b.pdf
fig1c.pdf [17 KiB]
HiDef png [186 KiB]
Thumbnail [151 KiB]
*.C file
fig1c.pdf
fig1d.pdf [19 KiB]
HiDef png [204 KiB]
Thumbnail [169 KiB]
*.C file
fig1d.pdf

Distribution of $\Delta m( D ^0 \pi ^0 )$ invariant mass. The full (red) line describes the fitting function. The dashed line shows the background contribution and the dotted vertical lines define the $D^{*0}$ signal region.

 fig2.pdf [16 KiB]
HiDef png [165 KiB]
Thumbnail [138 KiB]
*.C file
fig2.pdf

Distribution of the $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ invariant mass for $ D ^0 \rightarrow K ^- \pi ^+ $ decay. The full (red) line describes the fitting function. The dashed line displays the fitted background and the dotted lines the $ D_{s1}(2536)^{+}$ , $ D^*_{s2}(2573)^{+}$ , $ D^*_{s1}(2700)^+$ , $ D_{sJ}^{*}(2860)^+$ and $ D_{sJ}(3040)^+$ contributions. The inset displays the $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ mass spectrum after subtracting the fitted background.

 fig3.pdf [40 KiB]
HiDef png [287 KiB]
Thumbnail [229 KiB]
*.C file
fig3.pdf

Mass spectrum of $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ candidates for $ D ^0 \rightarrow K ^- \pi ^+ $ in (a) the NP sample, and (b) the UP sample. The full (red) lines describe the fitting function. The dashed lines show the fitted background and the dotted lines the $ D^*_{s2}(2573)^{+}$ , $ D^*_{s1}(2700)^+$ , $ D_{sJ}^{*}(2860)^+$ and $ D_{sJ}(3040)^+$ contributions. The insets display the $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ mass spectrum after subtracting the fitted background.

 fig4a.pdf [44 KiB]
HiDef png [305 KiB]
Thumbnail [243 KiB]
*.C file
fig4a.pdf
fig4b.pdf [43 KiB]
HiDef png [287 KiB]
Thumbnail [238 KiB]
*.C file
fig4b.pdf

Mass spectrum of (a) $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ candidates for $ D ^0 \rightarrow K ^- \pi ^+ \pi ^+ \pi ^- $ , and (b) $ D ^{*0} K ^+ $ candidates for the NP sample. The full (red) lines describe the fitting function. The dashed lines show the fitted background and the dotted lines the $ D^*_{s2}(2573)^{+}$ , $ D^*_{s1}(2700)^+$ , $ D_{sJ}^{*}(2860)^+$ and $ D_{sJ}(3040)^+$ contributions. The insets display the $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ and $ D ^{*0} K ^+ $ mass spectra after subtracting the fitted background.

 fig5a.pdf [45 KiB]
HiDef png [340 KiB]
Thumbnail [293 KiB]
*.C file
fig5a.pdf
fig5b.pdf [43 KiB]
HiDef png [323 KiB]
Thumbnail [276 KiB]
*.C file
fig5b.pdf

Distribution of the invariant mass of $ D ^+ K ^0_{\mathrm{ \scriptscriptstyle S}} $ candidates from Ref. [10]. The full (red) line is the result from the fit described in the text. The dashed line indicates the fitted background and the dotted line shows the fitted $ D^*_{s2}(2573)^{+}$ contribution.

 fig6.pdf [28 KiB]
HiDef png [208 KiB]
Thumbnail [156 KiB]
*.C file
fig6.pdf

Mass spectra, in the $ D_{s1}(2536)^{+}$ mass region, for the NP sample of (a) $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ with $ D ^0 \rightarrow K ^- \pi ^+ $ , (b) $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ with $ D ^0 \rightarrow K ^- \pi ^+ \pi ^+ \pi ^- $ , and (c) $ D ^{*0} K ^+ $ final states. The full (red) lines describe the fitting function. The dashed lines show the fitted background and the dotted lines the $ D^*_{s2}(2573)^{+}$ contributions. The insets display the $ D ^* K$ mass spectra after subtracting the fitted background.

 fig7a.pdf [25 KiB]
HiDef png [228 KiB]
Thumbnail [186 KiB]
*.C file
fig7a.pdf
fig7b.pdf [26 KiB]
HiDef png [235 KiB]
Thumbnail [192 KiB]
*.C file
fig7b.pdf
fig7c.pdf [24 KiB]
HiDef png [215 KiB]
Thumbnail [174 KiB]
*.C file
fig7c.pdf

Distributions of the measured signal yields for (a) $ D_{s1}(2536)^{+}$ and (b) $ D^*_{s2}(2573)^{+}$ as a function of the helicity angle $\cos\theta_{\rm H}$ . The distributions are fitted with UP (a) and NP (b) functions.

 fig8a.pdf [14 KiB]
HiDef png [156 KiB]
Thumbnail [136 KiB]
*.C file
fig8a.pdf
fig8b.pdf [14 KiB]
HiDef png [163 KiB]
Thumbnail [143 KiB]
*.C file
fig8b.pdf

Distributions of the measured signal yields for (a) $ D^*_{s1}(2700)^+$ , (b) $ D_{sJ}^{*}(2860)^+$ and (c) $ D_{sJ}(3040)^+$ as a function of the helicity angle $\cos\theta_{\rm H}$ . The distributions are fitted with NP (a,b) and UP (c) functions.

 fig9a.pdf [15 KiB]
HiDef png [171 KiB]
Thumbnail [153 KiB]
*.C file
fig9a.pdf
fig9b.pdf [15 KiB]
HiDef png [187 KiB]
Thumbnail [174 KiB]
*.C file
fig9b.pdf
fig9c.pdf [15 KiB]
HiDef png [162 KiB]
Thumbnail [143 KiB]
*.C file
fig9c.pdf

Animated gif made out of all figures.

 PAPER-2015-052.gif
Thumbnail
thumbnail_PAPER-2015-052.gif

Tables and captions

Results from the fits to the $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ and $ D ^{*0} K ^+ $ mass spectra. Resonances parameters are expressed in $\mathrm{ Me V}$ . When two uncertainties are presented, the first is statistical and the second systematic. The symbol ndf indicates the number of degrees of freedom.

 Table_1.pdf [63 KiB]
HiDef png [137 KiB]
Thumbnail [64 KiB]
tex code 		Table_1.pdf

Contributions (in $\mathrm{ Me V}$ ) to the systematic uncertainties on the $ D^*_{s1}(2700)^+ $ and $ D_{sJ}^{*}(2860)^+ $ resonances parameters.

 Table_2.pdf [46 KiB]
HiDef png [37 KiB]
Thumbnail [16 KiB]
tex code 		Table_2.pdf

Results from the fits to the $ D ^+ K ^0_{\mathrm{ \scriptscriptstyle S}} $ and $ D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ mass spectra for the evaluation of the $ D^*_{s2}(2573)^{+} \rightarrow D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} $ relative branching fraction.

 Table_3.pdf [62 KiB]
HiDef png [68 KiB]
Thumbnail [32 KiB]
tex code 		Table_3.pdf

Measurements used to evaluate the $ D^*_{s2}(2573)^{+}$ relative branching fraction $\cal B ( D^*_{s2}(2573)^{+} \rightarrow D ^{*+} K ^0_{\mathrm{ \scriptscriptstyle S}} )/\cal B ( D^*_{s2}(2573)^{+} \rightarrow D ^+ K ^0_{\mathrm{ \scriptscriptstyle S}} )$.

 Table_4.pdf [61 KiB]
HiDef png [36 KiB]
Thumbnail [14 KiB]
tex code 		Table_4.pdf

Relative systematic uncertainties in the evaluation of the ratio of branching fractions $\cal R$ .

 Table_5.pdf [47 KiB]
HiDef png [53 KiB]
Thumbnail [23 KiB]
tex code 		Table_5.pdf

Values of $\chi^2/{\rm ndf}$ from the fits to the helicity angles distributions.

 Table_6.pdf [46 KiB]
HiDef png [86 KiB]
Thumbnail [41 KiB]
tex code 		Table_6.pdf

Created on 27 April 2024.