Search for the decay $B_s^0 \to D^{*\mp} \pi^\pm$

Information

LHCb-PAPER-2012-056
CERN-PH-EP-2013-025
arXiv:1302.6446 [PDF]

(Submitted on 26 Feb 2013)
Phys. Rev. D87 (2013) 071101(R)
Inspire 1221251

Tools

Abstract

A search for the decay Bs -> D*-+ \pi+- is presented using a data sample corresponding to an integrated luminosity of 1.0 fb-1 of pp collisions collected by LHCb. This decay is expected to be mediated by a W-exchange diagram, with little contribution from rescattering processes, and therefore a measurement of the branching fraction will help to understand the mechanism behind related decays such as Bs -> \pi+ \pi- and Bs -> D Dbar. Systematic uncertainties are minimised by using B0 -> D*-+ \pi+- as a normalisation channel. We find no evidence for a signal, and set an upper limit on the branching fraction of BR(Bs -> D*-+ \pi+-) < 6.1 (7.8) x10^(-6) at 90 (95) confidence level.

Figures and captions

Decay diagrams for (a) $ B ^0_ s \rightarrow D^{()+}D^{()-}$ via weak exchange, (b) $ B ^0_ s \rightarrow D^{()+}D^{()-}$ via penguin annihilation, (c) $ B ^0_ s \rightarrow D^{(*)-}\pi ^+ $ via weak exchange.	Fig1a.eps [17 KiB] HiDef png [47 KiB] Thumbnail [25 KiB] *.C file
	Fig1b.eps [18 KiB] HiDef png [64 KiB] Thumbnail [35 KiB] *.C file
	Fig1c.eps [17 KiB] HiDef png [45 KiB] Thumbnail [24 KiB] *.C file
Simultaneous fit to the full data sample in five bins of $\theta_{\rm bach}$: (a) 0--0.046, (b) 0.046--0.067, (c) 0.067--0.092, (d) 0.092--0.128 and (e) 0.128--0.4 $\rm rad$ . Note the $y$-axis scale is logarithmic and is the same for each bin. Data points are shown in black, the full PDF as a solid blue line and the component PDFs as: (red dot-dashed) partially reconstructed background, (magenta dashed) combinatorial background, (blue dashed) $ B ^0$ signal, (black dot-dashed) $ B ^0_ s $ signal and (green 3 dot-dashed) $ B ^0 \rightarrow D ^{*-} K ^+ $ background.	Fig2a.eps [56 KiB] HiDef png [256 KiB] Thumbnail [222 KiB] *.C file
	Fig2b.eps [55 KiB] HiDef png [252 KiB] Thumbnail [219 KiB] *.C file
	Fig2c.eps [54 KiB] HiDef png [255 KiB] Thumbnail [219 KiB] *.C file
	Fig2d.eps [54 KiB] HiDef png [252 KiB] Thumbnail [218 KiB] *.C file
	Fig2e.eps [55 KiB] HiDef png [252 KiB] Thumbnail [218 KiB] *.C file
	Fig2f.eps [27 KiB] HiDef png [120 KiB] Thumbnail [130 KiB] *.C file
Animated gif made out of all figures.	PAPER-2012-056.gif Thumbnail