Search results for "semileptonic"

The Belle II Physics Book

2019

cd. autorów: L. Cao48,‡, G. Caria145,‡, G. Casarosa57,‡, C. Cecchi56,‡,D. Cˇ ervenkov10,‡,M.-C. Chang22,‡, P. Chang92,‡, R. Cheaib146,‡, V. Chekelian83,‡, Y. Chen154,‡, B. G. Cheon28,‡, K. Chilikin77,‡, K. Cho70,‡, J. Choi14,‡, S.-K. Choi27,‡, S. Choudhury35,‡, D. Cinabro170,‡, L. M. Cremaldi146,‡, D. Cuesta47,‡, S. Cunliffe16,‡, N. Dash33,‡, E. de la Cruz Burelo9,‡, E. de Lucia52,‡, G. De Nardo54,‡, †Editor. ‡Belle II Collaborator. §Theory or external contributing author. M. De Nuccio16,‡, G. De Pietro59,‡, A. De Yta Hernandez9,‡, B. Deschamps129,‡, M. Destefanis60,‡, S. Dey116,‡, F.Di Capua54,‡, S.Di Carlo75,‡, J. Dingfelder129,‡, Z. Doležal10,‡, I. Domínguez Jiménez125,‡, T.V. Dong30,26,…

Infinite momentum frame calculation of semileptonic heavyΛb→Λctransitions including HQET improvements

1997

We calculate the transition form factors that occur in heavy {Lambda}-type baryon semileptonic decays such as, e.g., in {Lambda}{sub b}{r_arrow}{Lambda}{sub c}{sup +}+l{sup {minus}}+{bar {nu}}{sub l}. We use Bauer-Stech-Wirbel-type infinite momentum frame wave functions for the heavy {Lambda}-type baryons which we assume to consist of a heavy quark and a light spin-isospin zero diquark system. The form factors at q{sup 2}=0 are calculated from the overlap integrals of the initial and final {Lambda}-type baryon states. To leading order in the heavy mass scale the structure of the form factors agrees with the HQET predictions including the normalization at zero recoil. The leading order {omeg…

$b\to c$ semileptonic decay of triply heavy baryons and $c\to s,d$ semileptonic decays of ground-state $cb$ baryons

2013

Systematic approach toβand2νββdecays of massA=100–136nuclei

2015

In this work we perform a systematic study of pairs of single-$\ensuremath{\beta}$-decaying nuclei in the mass region $A=100--136$ to extract information on the effective value of the axial-vector coupling constant ${g}_{\mathrm{A}}$. As the many-body framework we use the quasiparticle random-phase approximation (QRPA) and its proton-neutron variant (pnQRPA) in single-particle valence bases with Woods-Saxon-calculated single-particle energies. It is found that, to a reasonable approximation, ${g}_{\mathrm{A}}$ is a linear function of the mass number $A$, with a slightly different parametrization below and above the mass $A=121$. Using the values of ${g}_{\mathrm{A}}$ extracted from the line…

Observation of Photon Polarization in theb→sγTransition

2014

This Letter presents a study of the flavor-changing neutral current radiative $B^{\pm} \to K^{\pm}\pi^{\mp}\pi^{\pm}\gamma$ decays performed using data collected in proton-proton collisions with the LHCb detector at $7$ and $8\,$TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of $3\,\text{fb}^{-1}$, nearly $14\,000$ signal events are reconstructed and selected, containing all possible intermediate resonances with a $K^{\pm}\pi^{\mp}\pi^{\pm}$ final state in the $[1.1, 1.9]\,$GeV/$c^{2}$ mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in interva…

First experimental study of photon polarization in radiative B0s decays.

2017

The polarization of photons produced in radiative $B^{0}_{s}$ decays is studied for the first time. The data are recorded by the LHCb experiment in $pp$ collisions corresponding to an integrated luminosity of 3fb$^{-1}$ at center-of-mass energies of $7$ and $8$TeV. A time-dependent analysis of the $B^{0}_{s} \to \phi \gamma$ decay rate is conducted to determine the parameter ${\mathcal{A}}^\Delta$, which is related to the ratio of right- over left-handed photon polarization amplitudes in $b \to s \gamma$ transitions. A value of ${\mathcal{A}}^\Delta=-0.98^{\,+0.46\,+0.23}_{\,-0.52\,-0.20}$ is measured. This result is consistent with the Standard Model prediction within two standard deviatio…

Physics beyond colliders at CERN: beyond the Standard Model working group report

2019

The Physics Beyond Colliders initiative is an exploratory study aimed at exploiting the full scientific potential of the CERN's accelerator complex and scientific infrastructures through projects complementary to the LHC and other possible future colliders. These projects will target fundamental physics questions in modern particle physics. This document presents the status of the proposals presented in the framework of the Beyond Standard Model physics working group, and explore their physics reach and the impact that CERN could have in the next 10–20 years on the international landscape.

Measurement of the ratio ofBc+branching fractions toJ/ψπ+andJ/ψμ+νμfinal states

2014

The first measurement that relates semileptonic and hadronic decay rates of the B-c(+) meson is performed using proton-proton collision data corresponding to 1.0 fb(-1) of integrated luminosity collected with the LHCb detector. The measured value of the ratio of branching fractions, B(B-c(+) -> J/psi pi(+))/B(B-c(+) -> J/psi mu(+)nu(mu)) = 0.0469 +/- 0.0028(stat) +/- 0.0046(syst), is at the lower end of available theoretical predictions.

Precision measurement of D meson mass differences

2013

Using three- and four-body decays of D mesons produced in semileptonic b-hadron decays, precision measurements of D meson mass differences are made together with a measurement of the D-0 mass. The measurements are based on a dataset corresponding to an integrated luminosity of 1.0 fb(-1) collected in pp collisions at 7 TeV. Using the decay D-0 -> K+K-K-pi(+), the D-0 mass is measured to be M(D-0) = 1864.75 +/- 0.15 (stat) +/- 0.11 (syst) MeV/c(2). The mass differences M(D+) - M(D-0) = 4.76 +/- 0.12 (stat) +/- 0.07 (syst) MeV/c(2), M(D-s(+)) - M(D+) = 98.68 +/- 0.03 (stat) +/- 0.04 (syst) MeV/c(2) are measured using the D-0 -> K+K-pi(+)pi(-) and D-(s)(+) -> K+K-pi(+) modes.

Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

2019

Abstract The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ). In this view measurements of Heavy Ion (HI) induced Double Charge Exchange (DCE) reaction cross sections are performed with high-accuracy. In particular, the (18O,18Ne) and (20Ne,20O) reactions are used as tools for β+β+ and β-β- decays, respectively. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction ejectiles are detected the MAGNEX magnetic spectrometer. The measured cross sections are challe…