Search for the decay Aaij, R; Adeva, B; Adinolfi, M ...
The journal of high energy physics,
08/2015, Letnik:
2015, Številka:
8
Journal Article
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(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).A search for ... decays is performed using 3.0 fb super(1-) of pp collision data recorded by the LHCb experiment during ...2011 and 2012. The f sub(0)(980) meson is reconstructed through its decay to the pi super(+) pi super(-) final state in the mass window 900 MeV/c super(2) < m( pi super(+) pi super(-)) < 1080 MeV/c super(2). No significant signal is observed. The first upper limits on the branching fraction of ... are set at 90 % (95 %) confidence level. Figure not available: see fulltext.
A measurement of the CP asymmetry in B(+)→K(+)μ(+)μ(-) decays is presented using pp collision data, corresponding to an integrated luminosity of 1.0 fb(-1), recorded by the LHCb experiment during ...2011 at a center-of-mass energy of 7 TeV. The measurement is performed in seven bins of μ(+)μ(-) invariant mass squared in the range 0.05<q2<22.00 GeV2/c4, excluding the J/ψ and ψ(2S) resonance regions. Production and detection asymmetries are corrected for using the B(+)→J/ψK(+) decay as a control mode. Averaged over all the bins, the CP asymmetry is found to be A(CP)=0.000±0.033 (stat)±0.005 (syst)±0.007 (J/ψK), where the third uncertainty is due to the CP asymmetry of the control mode. This is consistent with the standard model prediction.
Abstract A combination of measurements sensitive to the CKM angle γ from LHCb is performed. The inputs are from analyses of time-integrated B + arrow right DK +, B 0 arrow right DK 0, B 0 arrow right ...DK +pi- and B + arrow right DK +pi+pi- tree-level decays. In addition, results from a time-dependent analysis of B s 0 arrow rightD s K ± decays are included. The combination yields γ=(72.2 -7.3 +6.8 )°, where the uncertainty includes systematic effects. The 95.5% confidence level interval is determined to be γ 55.9, 85.2°. A second combination is investigated, also including measurements from B + arrow right Dpi+ and B + arrow right Dpi+pi-pi+ decays, which yields compatible results. Figure not available: see fulltext.
Two narrow resonant states are observed in the Λ_{b}^{0}K^{-}π^{+} mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment ...and corresponding to an integrated luminosity of 6 fb^{-1}. The minimal quark content of the Λ_{b}^{0}K^{-}π^{+} system indicates that these are excited Ξ_{b}^{0} baryons. The masses of the Ξ_{b}(6327)^{0} and Ξ_{b}(6333)^{0} states are mΞ_{b}(6327)^{0}=6327.28_{-0.21}^{+0.23}±0.12±0.24 and mΞ_{b}(6333)^{0}=6332.69_{-0.18}^{+0.17}±0.03±0.22 MeV, respectively, with a mass splitting of Δm=5.41_{-0.27}^{+0.26}±0.12 MeV, where the uncertainties are statistical, systematic, and due to the Λ_{b}^{0} mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of ΓΞ_{b}(6327)^{0}<2.20(2.56) and ΓΞ_{b}(6333)^{0}<1.60(1.92) MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξ_{b}^{0} resonances.
A search for the decay
is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of
, collected by the LHCb experiment at centre-of-mass energies of ...7 and 8
. The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of
at
confidence level. This result improves the previous upper limit on the branching fraction by an order of magnitude.
Two new algorithms for use in the analysis of Formula: see text collision are developed to identify the flavour of Formula: see text mesons at production using pions and protons from the ...hadronization process. The algorithms are optimized and calibrated on data, using Formula: see text decays from Formula: see text collision data collected by LHCb at centre-of-mass energies of 7 and 8 TeV . The tagging power of the new pion algorithm is 60% greater than the previously available one; the algorithm using protons to identify the flavour of a Formula: see text meson is the first of its kind.
Using decays to
-meson pairs, the inclusive production of charmonium states in
-hadron decays is studied with
collision data corresponding to an integrated luminosity of
, collected by the LHCb ...experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by
the inclusive branching fraction of a
hadron to a charmonium state
that decays into a pair of
mesons, ratios
are determined as
,
,
,
,
and
. Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of
(3872),
(3915) and
states are obtained as
,
and
. Differential cross-sections as a function of transverse momentum are measured for the
and
states. The branching fraction of the decay
is measured for the first time,
. Here the third uncertainty is due to the branching fraction of the decay
, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse
polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the
decays to
and
as
.
The decays Formula: see text and Formula: see text are observed for the first time using a data sample corresponding to an integrated luminosity of 3.0 fbFormula: see text, collected by the LHCb ...experiment in proton-proton collisions at the centre-of-mass energies of 7 and 8Formula: see text. The branching fractions relative to that of Formula: see text are measured to be Formula: see textwhere the first uncertainties are statistical and the second are systematic.
An amplitude analysis of flavor-untagged B_{s}^{0}→J/ψppover ¯ decays is performed using a sample of 797±31 decays reconstructed with the LHCb detector. The data, collected in proton-proton ...collisions between 2011 and 2018, correspond to an integrated luminosity of 9 fb^{-1}. Evidence for a new structure in the J/ψp and J/ψpover ¯ systems with a mass of 4337_{-4}^{+7} _{-2}^{+2} MeV and a width of 29_{-12}^{+26} _{-14}^{+14} MeV is found, where the first uncertainty is statistical and the second systematic, with a significance in the range of 3.1 to 3.7σ, depending on the assigned J^{P} hypothesis.
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