Branching fraction and \textbf{\textit{CP}} asymmetry of the decays $B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+$ and $B^+ \to K_{\rm \scriptscriptstyle S}^0 K^+$
R. Aaij
,
Y. Amhis
(1)
,
S. Barsuk
(1)
,
O. Callot
(1)
,
J. He
(1)
,
O. Kochebina
(1)
,
J. Lefrançois
(1)
,
F. Machefert
(1)
,
A. Martin Sanchez
(1)
,
Marie Nicol
(1)
,
P. Robbe
(1)
,
M.-H. Schune
(1)
,
M. Teklishyn
(1)
,
A. Vallier
(1)
,
B. Viaud
(1)
,
E. Ben-Haim
(2)
,
M. Benayoun
(2)
,
P. David
(2)
,
L. del Buono
(2)
,
A. Martens
(2)
,
D.A. Milanes
(2)
,
F. Polci
(2)
,
C. Adrover
(3)
,
E. Aslanides
(3)
,
J. Cogan
(3)
,
W. Kanso
(3)
,
R. Legac
(3)
,
O. Leroy
(3)
,
G. Mancinelli
(3)
,
E. Maurice
(3)
,
A. Mordà
(3)
,
M. Perrin-Terrin
(3)
,
M. Sapunov
(3)
,
J. Serrano
(3)
,
A. Tsaregorodtsev
(3)
,
I. de Bonis
(4)
,
D. Decamp
(4)
,
N. Déléage
(4)
,
Ph. Ghez
(4)
,
P. Hopchev
(4)
,
J.-P. Lees
(4)
,
I.V. Machikhiliyan
(4)
,
M.-N. Minard
(4)
,
B. Pietrzyk
(4)
,
W. Qian
(4)
,
S. t'Jampens
(4)
,
V. Tisserand
(4)
,
E. Tournefier
(4)
,
Ziad Zj Ajaltouni
(5)
,
M. Baalouch
(5)
,
E. Cogneras
(5)
,
O. Deschamps
(5)
,
I. El Rifai
(5)
,
M. Grabalosa Gándara
(5)
,
Pierre Henrard
(5)
,
M. Hoballah
(5)
,
R. Lefèvre
(5)
,
L. Li Gioi
(5)
,
J. Maratas
(5)
,
S. Monteil
(5)
,
V. Niess
(5)
,
Pascal Perret
(5)
,
Diego Alejandro Roa Romero
(5)
R. Aaij
- Function : Author
J. He
- Function : Author
- PersonId : 756138
- ORCID : 0000-0001-8179-417X
L. del Buono
- Function : Author
- PersonId : 742055
- IdHAL : luigi-del-buono
- IdRef : 253135834
A. Martens
- Function : Author
- PersonId : 738690
- IdHAL : aurelien-martens
J. Cogan
- Function : Author
- PersonId : 750510
- IdHAL : julien-cogan
- ORCID : 0000-0001-7194-7566
- IdRef : 078779014
O. Leroy
- Function : Author
- PersonId : 171866
- IdHAL : olivier-leroy
- ORCID : 0000-0002-2589-240X
- IdRef : 169871835
M. Perrin-Terrin
- Function : Author
- PersonId : 741779
- IdHAL : perrin-terrin
- ORCID : 0000-0002-3568-1956
- IdRef : 179269666
J. Serrano
- Function : Author
- PersonId : 175327
- IdHAL : justine-serrano
- ORCID : 0000-0003-2489-7812
- IdRef : 127525521
S. t'Jampens
- Function : Author
- PersonId : 736045
- IdHAL : stephane-tjampens
- ORCID : 0000-0003-4249-6641
Ziad Zj Ajaltouni
- Function : Author
- PersonId : 903794
E. Cogneras
- Function : Author
- PersonId : 743220
- IdHAL : eric-cogneras
- ORCID : 0000-0002-8933-9427
O. Deschamps
- Function : Author
- PersonId : 12089
- IdHAL : olivier-deschamps
- ORCID : 0000-0002-7047-6042
- IdRef : 161447368
Pierre Henrard
- Function : Author
- PersonId : 829303
M. Hoballah
- Function : Author
- PersonId : 1174785
- IdHAL : mostafa-adam-hoballah-hobart
Pascal Perret
- Function : Author
- PersonId : 739797
- IdHAL : pascal-perret
- ORCID : 0000-0002-5732-4343
Diego Alejandro Roa Romero
- Function : Author
- PersonId : 769524
- IdRef : 172096839
Abstract
An analysis of $B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+$ and $B^+ \to K_{\rm \scriptscriptstyle S}^0 K^+$ decays is performed with the LHCb experiment. The $pp$ collision data used correspond to integrated luminosities of $1{\,fb}^{-1}$ and $2{\,fb}^{-1}$ collected at centre-of-mass energies of $\sqrt{s}=7\mathrm{\,Te\kern -0.1em V}$ and $\sqrt{s}=8\mathrm{\,Te\kern -0.1em V}$, respectively. The ratio of branching fractions and the direct {\it CP} asymmetries are measured to be $\mathcal{B}(B^+ \to K_{\rm \scriptscriptstyle S}^0 K^+)/\mathcal{B}(B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+) = 0.064 \pm 0.009\textrm{(stat.)} \pm 0.004\textrm{(syst.)}$, $\mathcal{A}^{\it CP}(B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+) = -0.022 \pm 0.025\textrm{(stat.)} \pm 0.010\textrm{(syst.)}$ and $\mathcal{A}^{\it CP}(B^+ \to K_{\rm \scriptscriptstyle S}^0 K^+) = -0.21 \pm 0.14\textrm{(stat.)} \pm 0.01\textrm{(syst.)}$. The data sample taken at $\sqrt{s}=7\mathrm{\,Te\kern -0.1em V}$ is used to search for $B_c^+ \to K_{\rm \scriptscriptstyle S}^0 K^+$ decays and results in the upper limit $(f_c\cdot\mathcal{B}(B_c^+ \to K_{\rm \scriptscriptstyle S}^0 K^+))/(f_u\cdot\mathcal{B}(B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+)) < 5.8\times10^{-2}\textrm{at 90% confidence level}$, where $f_c$ and $f_u$ denote the hadronisation fractions of a $\bar{b}$ quark into a $B_c^+$ or a $B^+$ meson, respectively.