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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…

高能物理 - 唯象学 · 物理学 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…

机器学习 · 统计学 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…

数值分析 · 数学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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,…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

统计理论 · 数学 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…

机器学习 · 统计学 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…

应用统计 · 统计学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

应用统计 · 统计学 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…

高能物理 - 唯象学 · 物理学 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…

高能物理 - 唯象学 · 物理学 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…

统计方法学 · 统计学 2010-08-30 Nicolas Dobigeon , Jean-Yves Tourneret