Related papers: Angular distribution of polarised $\Lambda_b$ bary…

Rare decays are flavour changing neutral current processes that are loop-suppressed in the Standard Model (SM). New particles in SM extensions can therefore give significant contributions, modifying branching fractions and angular…

We study the decays of $\Lambda_b \to \Lambda(\to p \pi^-) \ell ^+ \ell^-$ with $\ell = (e, \mu, \tau)$. In particular, we examine the full angular distributions with polarized $\Lambda_b$ and identify the time-reversal asymmetries or T-odd…

In 2015, the LHCb collaboration has measured $\frac{d{\mathcal{B}}}{dq^2}$, the lepton- and hadron-side forward-backward asymmetries, denoted by $A^\ell_{FB}$ and $A^{\Lambda}_{FB}$, respectively in the range $15 < q^2(=s) < 20$ GeV$^2$…

In new-physics processes that produce b or c jets, a measurement of the initial b or c-quark polarization could provide crucial information about the structure of the new physics. In the heavy-quark limit, the b and c-quark polarizations…

An analysis of the decay $\Lambda_b \to J/\psi(\to\mu^+\mu^-)\Lambda(\to p \pi^-)$ decay is performed to measure the $\Lambda_b$ polarization and three angular parameters in data from pp collisions at $\sqrt{s} =$ 7 and 8 TeV, collected by…

We report the observation of the baryonic decay $\bar{B}^0 \to \Lambda^+_c \bar{p} K^- K^+$ using a data sample of $471 \times 10^6$ $B\bar{B}$ pairs produced in $e^+e^-$ annihilations at $\sqrt{s}=10.58 \mathrm{\,GeV}$. This data sample…

A search for the rare decay $B^{+} \to \bar \Lambda p \mu^{+} \mu^{-}$ is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of $\sqrt{s}= 13$ TeV, corresponding to an integrated…

A study of the angular distributions of the processes $\Lambda_b \to {\Lambda} V(1^-)$ with $V ({J/\Psi,\rho}^0)$ is performed. Emphasis is put on the initial $\Lambda_b$ polarization and the polarization density-matrices are derived to…

We investigate the ten independent local form-factors relevant to the $b$-baryon decay $\Lambda_b \to \Lambda \ell^+\ell^-$, combining information of lattice QCD and dispersive bounds. We propose a novel parametrization of the form factors…

Recently hints of lepton flavor non-universality emerged when the BaBar Collaboration observed deviations from the standard model predictions in $R(D^{(*)}) \equiv {\cal B}({\bar B} \to D^{(*)+} \tau^- {\bar\nu}_\tau) / {\cal B}({\bar B}…

We study the decays of $\Lambda_b \to \Lambda_c(\to B_n f) \ell ^- \overline{\nu}$ with $\ell = e, \mu, \tau$, where $B_n$ and $f$ are the daughter baryons and the rest of the particles in $\Lambda_c$ cascade decays, respectively. In…

A complete study of teh angualr distributions of the process Lambda_b to Lambda V(1-) with lambda to p pi- and V(J/Psi) to l+l- or V(rho0,omega, phi) to pi+ pi-, K+K- is performed. Emphasis is put on the initial Lambda-b polarization…

The LHCb experiment, bolstered up by the 10^12 b-hadrons to be produced yearly in its interaction region, is an excellent place to study rare B decays. Flavor-changing neutral currents are forbidden at tree level in the Standard Model. They…

A selection of recent heavy-flavor results from OPAL using the LEP1 data sample are presented. The average polarization of b baryons in hadronic Z^0 decay has been measured to be -0.56^{+0.20}_{-0.13} (stat.) +- 0.09(syst.) using…

We present the first measurement of the angular distribution for the exclusive process $\bar p p \to \psi(2S)\to e^+e^-$ based on a sample of 6844 events collected by the Fermilab E835 experiment. We find that the angular distribution is…

A search for the charmless baryonic decay $B^+\to \bar{\Lambda} p\bar{p}p$ is performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 5.4~$\text{fb}^{-1}$. The branching…

A search is performed for the as yet unobserved baryonic $\Lambda_b \rightarrow \Lambda \eta^\prime$ and $\Lambda_b \rightarrow \Lambda \eta$ decays with 3$fb^{-1}$ of proton-proton collision data recorded by the LHCb experiment. The $B^0…

We propose two different and complementary observables for singling out possible signals of physics beyond the standard model in the semi-leptonic decays $\Lambda_b \to \Lambda_c \ell{\bar \nu}_{\ell}$, both with the $\tau$ lepton and with…

An angular analysis of the rare decay $B^0_s\rightarrow\phi\mu^+\mu^-$ is presented, using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of $7$, $8$ and $13~\rm{TeV}$, corresponding to an…

A search for the rare two-body charmless baryonic decay $B^+ \to p \bar\Lambda$ is performed with $pp$ collision data, corresponding to an integrated luminosity of $3\,\mbox{fb}^{-1}$, collected by the LHCb experiment at centre-of-mass…