A model-independent measurement of the CKM angle $\gamma$ in partially reconstructed $B^{\pm} \to D^{*} h^{\pm}$ decays with $D \to K_{S}^{0} h^{+}h^{-}$ $(h=\pi, K)$

Information

LHCb-PAPER-2023-029
CERN-EP-2023-241
arXiv:2311.10434 [PDF]

(Submitted on 17 Nov 2023)
JHEP 02 (2024) 118
Inspire 2724083

Tools

Abstract

A measurement of $C P$ -violating observables in $B^{\pm} \to D^{*} K^{\pm}$ and $B^{\pm} \to D^{*} \pi^{\pm}$ decays is made where the photon or neutral pion from the $D^{*} \to D\gamma$ or $D^{*} \to D\pi^{0}$ decay is not reconstructed. The $D$ meson is reconstructed in the self-conjugate decay modes, $D \to K_{S}^{0} \pi^{+} \pi^{-}$ or $D \to K_{S}^{0} K^{+} K^{-}$ . The distribution of signal yields in the $D$ decay phase space is analysed in a model-independent way. The measurement uses a data sample collected in proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of approximately 9 fb $^{-1}$ . The $B^{\pm} \to D^{*} K^{\pm}$ and $B^{\pm} \to D^{*} \pi^{\pm}$ $C P$ -violating observables are interpreted in terms of hadronic parameters and the CKM angle $\gamma$ , resulting in a measurement of $\gamma = (92^{+21}_{-17})^{\circ}$ . The total uncertainty includes the statistical and systematic uncertainties, and the uncertainty due to external strong-phase inputs.

Figures and captions

Mass distributions for (left) $D K$ samples and (right) $D \pi$ samples, with $D \rightarrow K ^0_{\mathrm{S}} \pi ^+ \pi ^-$ decays reconstructed with a (top) downstream $K ^0_{\mathrm{S}}$ candidate and a (bottom) long $K ^0_{\mathrm{S}}$ candidate. The projections of the fit results are overlaid. In the legend, particles in square brackets are not reconstructed.	Fig1a.pdf [196 KiB] HiDef png [459 KiB] Thumbnail [214 KiB] *.C file
	Fig1b.pdf [194 KiB] HiDef png [404 KiB] Thumbnail [190 KiB] *.C file
	Fig1c.pdf [195 KiB] HiDef png [486 KiB] Thumbnail [221 KiB] *.C file
	Fig1d.pdf [194 KiB] HiDef png [415 KiB] Thumbnail [196 KiB] *.C file
Mass distributions for (left) $D K$ samples and (right) $D \pi$ samples, with $D \rightarrow K ^0_{\mathrm{S}} K ^+ K ^-$ decays reconstructed with a (top) downstream $K ^0_{\mathrm{S}}$ candidate and a (bottom) long $K ^0_{\mathrm{S}}$ candidate. The projections of the fit results are overlaid. In the legend, particles in square brackets are not reconstructed.	Fig2a.pdf [194 KiB] HiDef png [473 KiB] Thumbnail [218 KiB] *.C file
	Fig2b.pdf [194 KiB] HiDef png [427 KiB] Thumbnail [200 KiB] *.C file
	Fig2c.pdf [193 KiB] HiDef png [490 KiB] Thumbnail [231 KiB] *.C file
	Fig2d.pdf [193 KiB] HiDef png [431 KiB] Thumbnail [202 KiB] *.C file
Contours at 68.3% and 95.5% confidence levels indicated by the darker and lighter regions, respectively, for (left, red) $(x_{-}^{ D ^* K }, y_{-}^{ D ^* K })$ which is labelled $B ^-$ and (left, purple) $(x_{+}^{ D ^* K }, y_{+}^{ D ^* K })$ which is labelled $B ^+$ , and (right) $(\Re(\xi^{ D ^* \pi}), \Im(\xi^{ D ^* \pi}))$ , including only statistical uncertainty. The black points indicate the central values.	Fig3.pdf [196 KiB] HiDef png [248 KiB] Thumbnail [117 KiB] *.C file
Confidence intervals at 68.3% and 95.5% for the CKM angle $\gamma$ .	Fig4.pdf [14 KiB] HiDef png [208 KiB] Thumbnail [115 KiB] *.C file
Confidence regions at 68.3% and 95.5% indicated by the lighter and darker shades respectively, for (top, left) $\gamma$ vs. $r_{B}^{ D ^* K }$ , (top, right) $\gamma$ vs. $\delta_{B}^{ D ^* K }$ , (bottom left) $\gamma$ vs. $r_{B}^{ D ^* \pi}$ , and (bottom, right) $\gamma$ vs. $\delta_{B}^{ D ^* \pi}$ .	Fig5a.pdf [14 KiB] HiDef png [368 KiB] Thumbnail [184 KiB] *.C file
	Fig5b.pdf [14 KiB] HiDef png [357 KiB] Thumbnail [177 KiB] *.C file
	Fig5c.pdf [17 KiB] HiDef png [382 KiB] Thumbnail [194 KiB] *.C file
	Fig5d.pdf [19 KiB] HiDef png [547 KiB] Thumbnail [280 KiB] *.C file
Animated gif made out of all figures.	PAPER-2023-029.gif Thumbnail

Tables and captions

Signal and background yields from the global fit over the full mass range, ${4900\textendash5600\text{ Me V /}c^2 }$ . All yields and uncertainties are rounded to the nearest integer and uncertainties of 1 mean one or fewer. Backgrounds that are not written explicitly in this table are included in the `Other Backgrounds' component.	Table_1.pdf [101 KiB] HiDef png [83 KiB] Thumbnail [36 KiB] tex code
Summary of the systematic uncertainties. Values are expressed in units of $10 ^{-2}$ .	Table_2.pdf [121 KiB] HiDef png [123 KiB] Thumbnail [55 KiB] tex code
Statistical correlation matrix for the $C P$ -violating observables.	Table_3.pdf [113 KiB] HiDef png [51 KiB] Thumbnail [24 KiB] tex code
Correlation matrix associated with LHCb-related systematic uncertainties.	Table_4.pdf [112 KiB] HiDef png [50 KiB] Thumbnail [24 KiB] tex code
Correlation matrix associated with the strong-phase inputs.	Table_5.pdf [113 KiB] HiDef png [51 KiB] Thumbnail [24 KiB] tex code

Created on 04 April 2025.

The LHCb Public results

A model-independent measurement of the CKM angle $\gamma$ in partially reconstructed $B^{\pm} \to D^{*} h^{\pm}$ decays with $D \to K_{S}^{0} h^{+}h^{-}$ $(h=\pi, K)$

Information

LHCb-PAPER-2023-029

CERN-EP-2023-241

arXiv:2311.10434 [PDF]

(Submitted on 17 Nov 2023)

JHEP 02 (2024) 118

Inspire 2724083

Tools

Cited 8 times

Get BibTex

Abstract

Figures and captions

Tables and captions

The LHCb Public results

A model-independent measurement of the CKM angle γ\gamma in partially reconstructed B±→D∗h±B^{\pm} \to D^{*} h^{\pm} decays with D→K0Sh+h−D \to K_{S}^{0} h^{+}h^{-}(h=π,K)(h=\pi, K)

Information

LHCb-PAPER-2023-029

CERN-EP-2023-241

arXiv:2311.10434 [PDF]

(Submitted on 17 Nov 2023)

JHEP 02 (2024) 118

Inspire 2724083

Tools

Cited 8 times

Get BibTex

Abstract

Figures and captions

Tables and captions

A model-independent measurement of the CKM angle $\gamma$ in partially reconstructed $B^{\pm} \to D^{*} h^{\pm}$ decays with $D \to K_{S}^{0} h^{+}h^{-}$ $(h=\pi, K)$