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Related papers: Dispersive bounds for local form factors in $\Lamb…

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We calculate the form factors for the $B \to D^*\ell\nu_\ell$ decay in 2+1 flavor lattice QCD. For all quark flavors, we employ the M\"obius domain-wall action, which preserves chiral symmetry to a good precision. Our gauge ensembles are…

High Energy Physics - Lattice · Physics 2024-06-05 Y. Aoki , B. Colquhoun , H. Fukaya , S. Hashimoto , T. Kaneko , R. Kellermann , J. Koponen , E. Kou

Recently, Stech found form factor relations for heavy to light transitions based on two simple dynamical assumptions for spectator partical. In this work we generalize his approach to the case of baryons and find that for…

High Energy Physics - Phenomenology · Physics 2016-09-06 X. -H. Guo , T. Hunag , Z. -H. Li

We analyze the tauonic semileptonic baryon decays $\Lambda^0_b \to \Lambda^+_c + \tau^{-} +\bar \nu_{\tau}$ with particular emphasis on the lepton helicity flip contributions which vanish for zero lepton masses. We calculate the total rate,…

High Energy Physics - Phenomenology · Physics 2015-12-09 Nurgul Habyl , Thomas Gutsche , Mikhail A. Ivanov , Jürgen G. Körner , Valery E. Lyubovitskij , Pietro Santorelli

We present a unified method for analysing form factors in B -> pi l nu-bar_l and B -> K* gamma decays. The analysis provides consistency checks on the q^2 and 1/M extrapolations necessary to obtain the physical decay rates. For the first…

High Energy Physics - Lattice · Physics 2010-11-01 UKQCD Collaboration , D. R. Burford , H. D. Duong , J. M. Flynn , B. J. Gough , N. M. Hazel , J. Nieves , H. P. Shanahan

The covariant Faddeev approach which describes baryons as relativistic three-quark bound states and is based on the Dyson-Schwinger and Bethe-Salpeter equations of QCD is briefly reviewed. All elements, including especially the baryons'…

High Energy Physics - Phenomenology · Physics 2018-08-01 Reinhard Alkofer , Christian S. Fischer , Helios Sanchis-Alepuz

We introduce a new parameterization of $B\rightarrow D \pi \ell \nu$ form factors using a partial-wave expansion and derive bounds on the series coefficients using analyticity and unitarity. This is the first generalization of the…

High Energy Physics - Phenomenology · Physics 2024-10-22 Erik J. Gustafson , Florian Herren , Ruth S. Van de Water , Raynette van Tonder , Michael L. Wagman

Branching ratios, lepton forward-backward asymmetries, and lepton polarization asymmetries for the flavor-changing neutral current (FCNC) dileptonic decays of the $\Lambda_b$ baryon to the ground state and a number of excited state…

Nuclear Theory · Physics 2015-10-28 L. Mott , W. Roberts

I discuss recent progress in lattice calculations of $B \to D^{(*)} \ell \nu$ form factors, important for the precision determination of $|V_{cb}|$ in the Standard Model (SM), and for testing SM expectations of lepton flavor universality in…

High Energy Physics - Lattice · Physics 2020-04-22 Andrew Lytle

In this work we discuss in detail the non-perturbative determination of the momentum dependence of the form factors entering in semileptonic decays using unitarity and analyticity constraints. The method contains several new elements with…

High Energy Physics - Lattice · Physics 2021-09-15 M. Di Carlo , G. Martinelli , M. Naviglio , F. Sanfilippo , S. Simula , L. Vittorio

The experimental uncertainty on the branching fraction $\b(\Lambda_c \to p K^- \pi^+) = (5.0 \pm 1.3)%$ has not decreased since 1998, despite a much larger data sample. Uncertainty in this quantity dominates that in many other quantities,…

High Energy Physics - Phenomenology · Physics 2013-05-30 Jonathan L. Rosner

We propose a method to determine the CKM matrix element $|V_{ub}|$ using the global $q^2$ dependence of the dispersive bound on the form factors for $B\to \pi l\nu$ decay. Since the lattice calculation of the $B\to \pi l\nu$ form factor is…

High Energy Physics - Lattice · Physics 2009-11-10 Masaru Fukunaga , Tetsuya Onogi

The form factors of the $\Lambda_{b} \to N^\ast \ell^+ \ell^-$ decay are calculated in the framework of the light cone QCD sum rules. In the calculations the contribution of the negative parity $\Lambda_b^\ast$ baryon is eliminated by…

High Energy Physics - Phenomenology · Physics 2019-05-22 T. M. Aliev , T. Barakat , M. Savci

The photoleptonic decay $B^-\to \gamma \ell^-\bar{\nu}$ is the simplest low-energy process that probes the substructure of the $B$ meson, making it an excellent candidate to determine the parameters of $B$-meson light-cone distribution…

High Energy Physics - Phenomenology · Physics 2026-02-10 Aoife Bharucha , Danny van Dyk , Eduardo Velásquez

We compute the order 1/m_b^3 nonperturbative contributions to the inclusive differential B\to X_c\ell\bar\nu decay rate. They are parametrized by the expectation values of two local and four nonlocal dimension-six operators. We use our…

High Energy Physics - Phenomenology · Physics 2011-01-27 Martin Gremm , Anton Kapustin

We present results of the first lattice QCD calculations of the weak matrix elements for the decays $B_c^+ \to D^0 \ell^+ \nu_{\ell}$, $B_c^+ \to D_s^+ \ell^+ \ell^-$ and $B_c^+ \to D_s^+ \nu \overline{\nu}$. Form factors across the entire…

High Energy Physics - Lattice · Physics 2021-11-15 Laurence Cooper , Christine Davies , Matthew Wingate

Following our earlier work we establish kinematic endpoint relations for baryon decays using the Wigner-Eckart theorem and apply them to $\frac{1}{2} \to \frac{1}{2}$ and $\frac{1}{2} \to \frac{3}{2}$ baryon transitions. We provide angular…

High Energy Physics - Phenomenology · Physics 2021-11-24 Gudrun Hiller , Roman Zwicky

We present a new method aiming at a non-perturbative, model-independent determination of the momentum dependence of the form factors entering semileptonic decays using unitarity and analyticity constraints. We extend the original proposal…

High Energy Physics - Lattice · Physics 2021-11-30 Matteo Di Carlo , Guido Martinelli , Manuel Naviglio , Francesco Sanfilippo , Silvano Simula , Ludovico Vittorio

We compute radiative corrections to $\Lambda_b \to \Lambda$ from factors, at next-to-leading logarithmic accuracy, from QCD light-cone sum rules with $\Lambda_b$-baryon distribution amplitudes. Employing the diagrammatic approach…

High Energy Physics - Phenomenology · Physics 2016-03-23 Yu-Ming Wang , Yue-Long Shen

We apply the strategy proposed in the companion paper [1] for dealing with multiple dispersive bounds, to the case of sub-threshold branch-cuts, which is a topic addressed extensively in the literature (see, e.g., Refs. [2-8]). We consider…

High Energy Physics - Phenomenology · Physics 2026-03-25 Silvano Simula , Ludovico Vittorio

The rare decays mediated by flavor-changing neutral current processes, such as $b \to s \ell^{+}\ell^{-}$, provide powerful probes of the Standard Model and potential windows into new physics. Particularly, the angular observables in these…

High Energy Physics - Phenomenology · Physics 2026-01-27 Rana Khan , Faisal Munir Bhutta , Ishtiaq Ahmed , M. Jamil Aslam