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Applying an operator product expansion approach we update the Standard Model prediction of the $B_c$ lifetime from over 20 years ago. The non-perturbative velocity expansion is carried out up to third order in the relative velocity of the…

High Energy Physics - Phenomenology · Physics 2021-08-04 Jason Aebischer , Benjamín Grinstein

Reliable predictive uncertainty estimation plays an important role in enabling the deployment of neural networks to safety-critical settings. A popular approach for estimating the predictive uncertainty of neural networks is to define a…

Machine Learning · Statistics 2023-12-29 Tim G. J. Rudner , Zonghao Chen , Yee Whye Teh , Yarin Gal

We develop fast and memory efficient numerical methods for learning functions of many variables that admit sparse representations in terms of general bounded orthonormal tensor product bases. Such functions appear in many applications…

Numerical Analysis · Mathematics 2020-05-11 Bosu Choi , Mark Iwen , Felix Krahmer

The structure function of a heavy quark in a heavy hadron in electroproduction is calculated from QCD. Its deviation from the parton model prediction (a delta function) is shown to be governed by a shape function, similar to the one…

High Energy Physics - Phenomenology · Physics 2009-09-25 D. Pirjol

An analytic result for the O(alpha_s corrections to the triple differential B -> X_u l nu decay rate is presented, to leading order in the heavy-quark expansion. This is relevant for computing partially integrated decay distributions with…

High Energy Physics - Phenomenology · Physics 2015-06-25 F. De Fazio , M. Neubert

Standard parton distribution function sets do not have rigorously quantified uncertainties. In recent years it has become apparent that these uncertainties play an important role in the interpretation of hadron collider data. In this paper,…

High Energy Physics - Phenomenology · Physics 2009-10-31 Walter T. Giele , Stephane Keller

We present expressions for shape variables of B decay distributions in several different mass schemes, to order $\alpha_s^2\beta_0$ and (Lambda_{QCD}/mb)^3. Such observables are sensitive to the b quark mass and matrix elements in the heavy…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christian W. Bauer , Zoltan Ligeti , Michael Luke , Aneesh V. Manohar

In this paper, we observe a fixed number of unknown $2\pi$-periodic functions differing from each other by both phases and amplitude. This semiparametric model appears in literature under the name "shape invariant model." While the common…

Statistics Theory · Mathematics 2010-10-06 Myriam Vimond

The shape of an object is an important characteristic for many vision problems such as segmentation, detection and tracking. Being independent of appearance, it is possible to generalize to a large range of objects from only small amounts…

Machine Learning · Statistics 2018-12-14 Alessandro Di Martino , Erik Bodin , Carl Henrik Ek , Neill D. F. Campbell

In this second part of our two-part paper, we provide a detailed, frequentist framework for propagating uncertainties within our multivariate linear least squares model. This permits us to quantify the impact of uncertainties in…

Applications · Statistics 2019-08-09 Pranay Seshadri , Andrew Duncan , Duncan Simpson , George Thorne , Geoffrey Parks

We propose determining |V_{ub}| from inclusive semileptonic B decay using combined cuts on the leptonic and hadronic invariant masses to eliminate the b->c background. Compared to a pure dilepton invariant mass cut, the uncertainty from…

High Energy Physics - Phenomenology · Physics 2010-05-28 Christian W. Bauer , Zoltan Ligeti , Michael Luke

We point out that current experimental data for partial B --> pi l nu branching fractions reduce the theoretical input required for a precise extraction of |V_ub| to the form factor normalization at a single value of the pion energy. We…

High Energy Physics - Phenomenology · Physics 2010-04-05 Thomas Becher , Richard J. Hill

We reduce the perturbative uncertainty in the determination of |V_{ub}| from inclusive semileptonic B decays by calculating the rate of B -> X_u l nu events with dilepton invariant mass q^2>(M_B-M_D)^2 at subleading order in the hybrid…

High Energy Physics - Phenomenology · Physics 2014-11-17 Matthias Neubert , Thomas Becher

We present a QCD-based approach to the endpoint region of the lepton spectrum in $\bar B\to X_u\,\ell\,\bar\nu$ decays. We introduce a genuinely nonperturbative form factor, the shape function, which describes the fall-off of the spectrum…

High Energy Physics - Phenomenology · Physics 2010-11-01 Matthias Neubert

The polarization of $\Lambda_b$ baryon has been measured in ALEPH, OPAL and DELPHI experiments. A significant loss on the transfer of the $b$ quark polarization to the $\Lambda_b$ baryon polarization has been noticed. This implies that the…

High Energy Physics - Phenomenology · Physics 2011-01-25 Tsung-Wen Yeh

The alternative to the standard formulation of QPM in the infinite momentum frame is suggested. The proposed approach does not require any extra assumptions in addition, consistently takes into account the parton transversal momenta and…

High Energy Physics - Phenomenology · Physics 2016-08-24 P. Zavada

The high energy physics unfolding problem is an important statistical inverse problem in data analysis at the Large Hadron Collider (LHC) at CERN. The goal of unfolding is to make nonparametric inferences about a particle spectrum from…

Applications · Statistics 2017-06-09 Mikael Kuusela , Philip B. Stark

We present a systematic study of the shape function for inclusive B-meson decays in the heavy-quark limit, which is based on the QCD equations of motion and heavy-quark symmetry, and takes into account the cusp divergence due to radiative…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hiroyuki Kawamura , Jiro Kodaira , Kazuhiro Tanaka

In order to extract some information on the CKM matrix element |Vcb|, we have to determine form factors in B decays. For this, we show that it is relevant to consider the non-forward amplitude between the heavy-light B and D mesons within…

High Energy Physics - Phenomenology · Physics 2007-05-23 F. Jugeau

This paper addresses the problem of identifying a lower dimensional space where observed data can be sparsely represented. This under-complete dictionary learning task can be formulated as a blind separation problem of sparse sources…

Methodology · Statistics 2010-08-30 Nicolas Dobigeon , Jean-Yves Tourneret