Measurement of the branching fraction and $$C\!P$$ C P asymmetry in $${{{B} ^+}} \!\rightarrow {{J /\psi }} {{\rho } ^+} $$ B + → J / ψ ρ + decays

Abstract

Abstract The branching fraction and direct

$$C\!P$$

C

P

asymmetry of the decay

$${{{B} ^+}} \!\rightarrow {{J /\psi }} {{\rho } ^+} $$

B

+

→

J / ψ

ρ

+

are measured using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to a total integrated luminosity of 3

$$\,\text{ fb }^{-1}$$

fb

- 1

. The following results are obtained:

$$\begin{aligned} \mathcal {B}({{B} ^+} \!\rightarrow {{J /\psi }} {{\rho } ^+} )&= (3.81^{+0.25}_{-0.24} \pm 0.35) \times 10^{-5},\\ \mathcal {A}^{{C\!P}} ({{B} ^+} \!\rightarrow {{J /\psi }} {{\rho } ^+} )&= -0.045^{+0.056}_{-0.057} \pm 0.008, \end{aligned}$$

B (

B

+

→

J / ψ

ρ

+

)

=

( 3 .

81

- 0.24

+ 0.25

± 0.35 )

×

10

- 5

,

A

C

P

(

B

+

→

J / ψ

ρ

+

)

= - 0 .

045

- 0.057

+ 0.056

± 0.008 ,

where the first uncertainties are statistical and the second systematic. Both measurements are the most precise to date.