Observation of the Annihilation Decay Mode B0→K+K−

Abstract

A search for the B 0 → K þ K − decay is performed using pp-collision data collected by LHCb. The data set corresponds to integrated luminosities of 1.0 and 2.0 fb −1 at center-of-mass energies of 7 and 8 TeV, respectively. This decay is observed for the first time, with a significance of more than 5 standard deviations. The analysis also results in an improved measurement of the branching fraction for the B . The first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the B 0 → K þ π − branching fraction used as a normalization. For the B 0 s mode, the fourth accounts for the uncertainty on the ratio of the probabilities for b quarks to hadronize into B 0 s and B 0 mesons.

Anatomy of B → PP decays and effects of the next-to-leading order contributions in the perturbative QCD approach

“…During the past three decades, the two-body charmless hadronic B s → P P decays ( P refers to the light pseudoscalar mesons π, K, η (′) ) have been studied intensively by many authors for example in Refs. [1][2][3][4][5][6][7][8][9][10][11][12][13] and measured by CDF, Belle and LHCb Collaborations [14][15][16][17][18][19][20][21][22][23][24][25][26]. The studies for these decays can offer us good opportunities to test the Standard Model (SM) and to search for the new physics (NP) beyond the SM.…”

Charmless two- and four-body b-hadron decays at LHCb

“…The B 0 → K + K − decay is the rarest fully hadronic b meson decay ever observed [2]. The measurement of the branching fraction of its U-spin partner, the B 0 s → π + π − , has been updated by the LHCb collaboration, achieving an unprecedented precision.…”

“…The understanding of the dynamics governing the decays of heavy-flavoured hadrons is factorization (QCDF) [1][2][3], perturbative QCD (pQCD) [4,5] and soft collinear e↵ective 9 theory (SCET) [6]. Despite the general progress in the field, calculations for a specific tool to improve our understanding of QCD in this field.…”

“…⇡ + ⇡ signal has already been established by LHCb [7], the is defined as the distance between the reconstructed trajectory of a particle and a given factorization (QCDF) [1][2][3], perturbative QCD (pQCD) [4,5] and soft collinear e↵ective 9 theory (SCET) [6]. Despite the general progress in the field, calculations for a specific in order to compute for each B candidate its likelihood for being signal or background.…”

Results from LHCb in charmless (quasi)-two body B meson decays

“…The B 0 → K + K − decay is the rarest mode in the family B → hh (with h = π, K) and the rarest fully hadronic B-meson decay ever observed [3]. In the SM, this rare mode, together with B 0 s → π + π − , proceeds predominantly through weak annihilation transitions.…”