Measurement of CP observables in B-+/- -> DK +/- and B-+/- -> D pi(+/-) with D -> KS0<mml:msup>K +/-</mml:msup><mml:msup>pi -/+</mml:msup> decays

Measurements of $CP$ observables in $B^\pm \to D K^\pm$ and $B^\pm \to D \pi^\pm$ decays are presented, where $D$ represents a superposition of $D^0$ and $\bar{D}^0$ states. The $D$ meson is reconstructed in the three-body final state $K_{\rm{S}}^0K^\pm \pi^\mp$. The analysis uses samples of $B$ mesons produced in proton-proton collisions, corresponding to an integrated luminosity of 1.0, 2.0, and 6.0 fb$^{-1}$ collected with the LHCb detector at centre-of-mass energies of $\sqrt{s} =$ 7, 8, and 13 TeV, respectively. These measurements are the most precise to date, and provide important input for the determination of the CKM angle $\gamma$

Precision measurement of the Lambda(+)(c) baryon mass

A precision measurement of the $B_{c}^{+}$ meson mass is performed using proton-proton collision data collected with the LHCb experiment at centre-of-mass energies of $7, 8$ and $13$ TeV, corresponding to a total integrated luminosity of $9.0 \,{\rm fb}^{-1}$. The $B_{c}^{+}$ mesons are reconstructed via the decays $B_{c}^{+} \rightarrow J\mskip -3mu/\mskip -2mu\psi\mskip 2mu \pi^+$, $B_{c}^{+} \rightarrow J\mskip -3mu/\mskip -2mu\psi\mskip 2mu \pi^+ \pi^- \pi^+$, $B_{c}^{+} \rightarrow J\mskip -3mu/\mskip -2mu\psi\mskip 2mu p \bar{p} \pi^+$, $B_{c}^{+} \rightarrow J\mskip -3mu/\mskip -2mu\psi\mskip 2mu D_{s}^{+}$, $B_{c}^{+} \rightarrow J\mskip -3mu/\mskip -2mu\psi\mskip 2mu D^{0} K^{+}$ and $B_{c}^{+} \rightarrow B_{s}^{0} \pi^{+}$. Combining the results of the individual decay channels, the $B_{c}^{+}$ mass is measured to be $6274.47 \pm 0.27 \,({\rm stat}) \pm 0.17 \,({\rm syst}) \mathrm{\,Me\kern -0.1em V}/c^{2}$. This is the most precise measurement of the $B_{c}^{+}$ mass to date. The difference between the $B_{c}^{+}$ and $B_{s}^{0}$ meson masses is measured to be $907.75 \pm 0.37 \,({\rm stat}) \pm 0.27 \,({\rm syst}) \mathrm{\,Me\kern -0.1em V}/c^{2}$

Measurement of branching fraction ratios for B+ -> D*+D-K+, B+ -> D*-D+K+, and B-0 -> (D*-DK+)-K-0 decays

A measurement of four branching-fraction ratios for three-body decays of $B$ mesons involving two open-charm hadrons in the final state is presented. Run 1 and Run 2 $pp$ collision data are used, recorded by the LHCb experiment at centre-of-mass energies $7$, $8$, and $13$ TeV and corresponding to an integrated luminosity of $9$ fb$^{-1}$. The measured branching-fraction ratios are \begin{eqnarray} \frac{\mathcal{B} (B^+\to D^{*+}D^-K^+)}{\mathcal{B} (B^+\to \kern 0.2em\overline{\kern -0.2em D}{}^0 D^0 K^+)} &=& 0.517 \pm 0.015 \pm 0.013 \pm 0.011 , \\ \frac{\mathcal{B} (B^+\to D^{*-}D^+K^+)}{\mathcal{B} (B^+\to \kern 0.2em\overline{\kern -0.2em D}{}^0 D^0 K^+)} &=& 0.577 \pm 0.016 \pm 0.013 \pm 0.013 , \\ \frac{\mathcal{B} (B^0\to D^{*-}D^0K^+)}{\mathcal{B} (B^0\to D^- D^0 K^+)} &=& 1.754 \pm 0.028 \pm 0.016 \pm 0.035 , \\ \frac{\mathcal{B} (B^+\to D^{*+}D^-K^+)}{\mathcal{B} (B^+\to D^{*-}D^+K^+)} &=& 0.907 \pm 0.033 \pm 0.014 ,\end{eqnarray} where the first of the uncertainties is statistical, the second systematic, and the third is due to the uncertainties on the $D$-meson branching fractions. These are the most accurate measurements of these ratios to date

Measurement of the B ± production cross-section in pp collisions at √s = 7 TeV

The production of B ± mesons in proton-proton collisions at √s = 7TeVis studied using 35 pb -1 of data collected by the LHCb detector. The B ± mesons are reconstructed exclusively in the B ± → J/ΨK ± mode, with J/Ψ→μ +μ -. The differential production cross-section is measured as a function of the B ± transverse momentum in the ducial region 0 &lt; pT &lt; 40 GeV=c and with rapidity 2:0 &lt; y &lt; 4:5. The total cross-section, summing up B + and B -, is measured to be σ(pp → B ±X; 0 &lt; pT &lt; 40 GeV=c; 2:0 &lt; y &lt; 4:5) = 41:4 ± 1:5 (stat:) ± 3:1 (syst:) μb. Copyright CERN

Measurement of the D+/- production asymmetry in 7 TeV pp collisions

The asymmetry in the production cross-section σ of D± mesons,AP=σ(D+)-σ(D-)σ(D+)+σ(D-), is measured in bins of pseudorapidity η and transverse momentum p<inf>T</inf> within the acceptance of the LHCb detector. The result is obtained with a sample of D+→KS0π+ decays corresponding to an integrated luminosity of 1.0 fb-1, collected in pp collisions at a centre of mass energy of 7 TeV at the Large Hadron Collider. When integrated over the kinematic range 2.0<p<inf>T</inf><18.0 GeV/c and 2.20<η<4.75, the production asymmetry is A<inf>P</inf>=(-0.96±0.26±0.18)%. The uncertainties quoted are statistical and systematic, respectively. The result assumes that any direct CP violation in the D+→KS0π+ decay is negligible. No significant dependence on η or p<inf>T</inf> is observed. © 2012 CERN

Measurement of the shape of the Bs0→Ds∗−μ+νμ differential decay rate

The shape of the B-s(0) -&gt; D-s*mu(+)nu(mu) differential decay rate is obtained as a function of the hadron recoil parameter using proton-proton collision data at a centreof-mass energy of 13TeV, corresponding to an integrated luminosity of 1.7 fb(-1) collected by the LHCb detector. The B-s(0) -&gt; D-s*(-)mu(+)nu(mu) decay is reconstructed through the decays D-s*(-) up arrow D-s(-) gamma and D-s(-) -&gt; K-K+pi(-). The differential decay rate is fitted with the CapriniLellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted

Measurement of branching fraction ratios for B+ → D*+D−K+, B+ → D*−D+K+, and B0 → D*−D0K+ decays

A measurement of four branching-fraction ratios for three-body decays of B mesons involving two open-charm hadrons in the final state is presented. Run 1 and Run 2 pp collision data are used, recorded by the LHCb experiment at centre-of-mass energies 7, 8, and 13 TeV and corresponding to an integrated luminosity of 9 fb(-1). The measured branching-fraction ratios areBB+-&gt; D+D-K+BB+-&gt; D0D0K+=0.5170.0150.013 +/- 0.011,BB+-&gt; D-D+K+BB+-&gt; D0D0K+=0.577 +/- 0.016 +/- 0.013 +/- 0.013,BB0 -&gt; D-D0K+BB0 -&gt; D-D0K+=1.754 +/- 0.028 +/- 0.016 +/- 0.035,BB+-&gt; D+D-K+BB+-&gt; D-D+K+=0.907 +/- 0.033+/- 0.014,where the first of the uncertainties is statistical, the second systematic, and the third is due to the uncertainties on the D-meson branching fractions. These are the most accurate measurements of these ratios to date

Measurement of CP-Averaged Observables in the B-0 -> K-star 0 mu(+)mu(-) Decay

An angular analysis of the B-0 -&gt; K-0 (-&gt; K+pi(-))mu(+)mu(-) decay is presented using a dataset corresponding to an integrated luminosity of 4.7 fb(-1) of pp collision data collected with the LHCb experiment. The full set of CP-averaged observables are determined in bins of the invariant mass squared of the dimuon system. Contamination from decays with the K+ pi(-) system in an S-wave configuration is taken into account. The tension seen between the previous LHCb results and the standard model predictions persists with the new data. The precise value of the significance of this tension depends on the choice of theory nuisance parameters

Searches for 25 rare and forbidden decays of D + and Ds+ mesons

A search is performed for rare and forbidden charm decays of the form D(s)+→h±ℓ+ℓ(′)∓, where h± is a pion or kaon and ℓ(′)± is an electron or muon. The measurements are performed using proton-proton collision data, corresponding to an integrated luminosity of 1.6 fb−1, collected by the LHCb experiment in 2016. No evidence is observed for the 25 decay modes that are investigated and 90 % confidence level limits on the branching fractions are set between 1.4 × 10−8 and 6.4 × 10−6. In most cases, these results represent an improvement on existing limits by one to two orders of magnitude. [Figure not available: see fulltext.

Road map for selected key measurements from LHCb

Six of the key physics measurements that will be made by the LHCb experiment, concerning CP asymmetries and rare B decays, are discussed in detail. The "road map" towards the precision measurements is presented, including the use of control channels and other techniques to understand the performance of the detector with the first data from the LHC.Six of the key physics measurements that will be made by the LHCb experiment, concerning CP asymmetries and rare B decays, are discussed in detail. The 'road map' towards the precision measurements is presented, including the use of control channels and other techniques to understand the performance of the detector with the first data from the LHC