arXiv subjects

Ya Li

Publications and source records attributed to Ya Li.

At least 109 records · Page 6Linked to original sources

arXiv2019

On Better Exploring and Exploiting Task Relationships in Multi-Task Learning: Joint Model and Feature Learning

Multitask learning (MTL) aims to learn multiple tasks simultaneously through the interdependence between different tasks. The way to measure the relatedness between tasks is always a popular issue. There are mainly two ways to measure relatedness between tasks: common parameters sharing and common features sharing across different tasks. However, these two types of relatedness are mainly learned independently, leading to a loss of information. In this paper, we propose a new strategy to measure the relatedness that jointly learns shared parameters and shared feature representations. The objective of our proposed method is to transform the features from different tasks into a common feature space in which the tasks are closely related and the shared parameters can be better optimized. We give a detailed introduction to our proposed multitask learning method. Additionally, an alternating algorithm is introduced to optimize the nonconvex objection. A theoretical bound is given to demonstrate that the relatedness between tasks can be better measured by our proposed multitask learning algorithm. We conduct various experiments to verify the superiority of the proposed joint model and feature a multitask learning method.

cs.LG↗

arXiv2019

Learning Efficient Lexically-Constrained Neural Machine Translation with External Memory

Recent years has witnessed dramatic progress of neural machine translation (NMT), however, the method of manually guiding the translation procedure remains to be better explored. Previous works proposed to handle such problem through lexcially-constrained beam search in the decoding phase. Unfortunately, these lexically-constrained beam search methods suffer two fatal disadvantages: high computational complexity and hard beam search which generates unexpected translations. In this paper, we propose to learn the ability of lexically-constrained translation with external memory, which can overcome the above mentioned disadvantages. For the training process, automatically extracted phrase pairs are extracted from alignment and sentence parsing, then further be encoded into an external memory. This memory is then used to provide lexically-constrained information for training through a memory-attention machanism. Various experiments are conducted on WMT Chinese to English and English to German tasks. All the results can demonstrate the effectiveness of our method.

cs.CL↗

arXiv2019

Quasi-two-body decays $B_{(s)}\to K^*(892)h\to Kπh$ in perturbative QCD approach

We extend our recent works on the $P$-wave two-pion resonant contributions to the kaon-pion cases in the hadronic charmless $B$ meson decays by employing the perturbative QCD approach. The concerned decay modes are analysed in the quasi-two-body framework by parameterizing the kaon-pion distribution amplitude $Φ_{K π}^{\rm P}$, which contains the final state interactions between the kaon and pion in the resonant region. The relativistic Breit-Wigner formula for the $P$-wave resonant state $K^*(892)$ is adopted to parameterize the time-like form factor $F_{Kπ}$. We calculate the $CP$-averaged branching ratios and direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)}\to K^*(892) h\to Kπh$, with $h=(π, K)$, in this work. It is shown that the agreement of theoretical results with the experimental data can be achieved, through which Gegenbauer moments of the $P$-wave kaon-pion distribution amplitudes are determined. The predictions in this work will be tested by the precise data from the LHCb and the future Belle II experiments.

hep-ph↗

arXiv2018

$P$-wave contributions to $B\toψππ$ decays in perturbative QCD approach

We present the differential branching fractions for the $B\rightarrow ψππ$ decays with the charmonia $ψ=J/ψ,ψ(2S)$ in the invariant mass of the $P$-wave pion pairs in the perturbative QCD approach. The two-pion distribution amplitudes (DAs) corresponding to both longitudinal and transverse polarizations are constructed to capture important final state interactions in the processes. The time-like form factors, normalizing the two-pion DAs, contains contributions from the $ρ$ resonance and radial excitations fitted to the BaBar data. Given the hadronic parameters for the two-pion DAs associated with the longitudinal polarization which were determined in our previous study, and tuning those associated with the transverse polarization, we accommodate well the observed branching ratios and polarization fractions of the $B\rightarrow J/ψππ$ decays. Our predictions for the $B\rightarrow ψ(2S) ππ$ modes from the same set of parameters can be tested in future LHCb and BelleII experiments. We also investigate the sources of theoretical uncertainties in our calculation.

hep-ph↗

arXiv2018

Quasi-two-body decays $B_{(s)}\to P f_2(1270)\to Pππ$ in the perturbative QCD approach

In this work, we calculate the $CP$-averaged branching ratios and direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)}\to P f_2(1270)\to Pππ$ with the two-pion distribution amplitude $Φ_{ππ}^{\rm D}$ by using the perturbative QCD factorization approach, where $P$ represents a light pseudoscalar meson $K, π, η$ and $η^{\prime}$. The relativistic Breit-Wigner formula for the $D$-wave resonance $f_2(1270)$ is adopted to parameterize the timelike form factor $F_π$, which contains the final state interactions between the pions in the resonant regions. The consistency of theoretical results with data can be achieved by determining the Gegenbauer moments of the $D$-wave two-pion distribution amplitudes. The decay rates for the considered decay modes are generally in the order of $10^{-9}$ to $ 10^{-6}$. The integrated direct $CP$ asymmetries for the charged modes agree with the {\it BABAR} and Belle measurements. As a by-product, we extract the branching ratios of $B_{(s)}\to Pf_2(1270)$ from the corresponding quasi-two-body decay modes, which still need experimental tests at the ongoing and forthcoming experiments.

hep-ph↗

arXiv2018

Investigation of Multimodal Features, Classifiers and Fusion Methods for Emotion Recognition

Automatic emotion recognition is a challenging task. In this paper, we present our effort for the audio-video based sub-challenge of the Emotion Recognition in the Wild (EmotiW) 2018 challenge, which requires participants to assign a single emotion label to the video clip from the six universal emotions (Anger, Disgust, Fear, Happiness, Sad and Surprise) and Neutral. The proposed multimodal emotion recognition system takes audio, video and text information into account. Except for handcraft features, we also extract bottleneck features from deep neutral networks (DNNs) via transfer learning. Both temporal classifiers and non-temporal classifiers are evaluated to obtain the best unimodal emotion classification result. Then possibilities are extracted and passed into the Beam Search Fusion (BS-Fusion). We test our method in the EmotiW 2018 challenge and we gain promising results. Compared with the baseline system, there is a significant improvement. We achieve 60.34% accuracy on the testing dataset, which is only 1.5% lower than the winner. It shows that our method is very competitive.

cs.CV↗

arXiv2018

Domain Generalization via Conditional Invariant Representation

Domain generalization aims to apply knowledge gained from multiple labeled source domains to unseen target domains. The main difficulty comes from the dataset bias: training data and test data have different distributions, and the training set contains heterogeneous samples from different distributions. Let $X$ denote the features, and $Y$ be the class labels. Existing domain generalization methods address the dataset bias problem by learning a domain-invariant representation $h(X)$ that has the same marginal distribution $\mathbb{P}(h(X))$ across multiple source domains. The functional relationship encoded in $\mathbb{P}(Y|X)$ is usually assumed to be stable across domains such that $\mathbb{P}(Y|h(X))$ is also invariant. However, it is unclear whether this assumption holds in practical problems. In this paper, we consider the general situation where both $\mathbb{P}(X)$ and $\mathbb{P}(Y|X)$ can change across all domains. We propose to learn a feature representation which has domain-invariant class conditional distributions $\mathbb{P}(h(X)|Y)$. With the conditional invariant representation, the invariance of the joint distribution $\mathbb{P}(h(X),Y)$ can be guaranteed if the class prior $\mathbb{P}(Y)$ does not change across training and test domains. Extensive experiments on both synthetic and real data demonstrate the effectiveness of the proposed method.

cs.LG↗

arXiv2017

Quasi-two-body decays $B_c \to D_{(s)} [ρ(770),ρ(1450),ρ(1700) \to ] ππ$ in the perturbative QCD factorization approach

In this paper, we studied the quasi-two-body $B_c \to D_{(s)} [ ρ(770),ρ(1450),ρ(1700) \to ] ππ$ decays by employing the perturbative QCD (PQCD) factorization approach. The two-pion distribution amplitudes $Φ_{ππ}$ are applied to include the final-state interactions between the pion pair, while the time-like form factors $F_π(w^2)$ associated with the $P$-wave resonant states $ρ(770)$, $ρ(1450)$ and $ρ(1700)$ are extracted from the experimental data of the $e^+e^-$ annihilation. We found that: (a) the PQCD predictions for the branching ratios of the quasi-two-body $B_c \to D_{(s)} [ρ(770), ρ(1450), ρ(1700) \to ] ππ$ decays are in the order of $10^{-9}$ to $ 10^{-5}$ and the direct $CP$ violations around $(10-40)\%$ in magnitude; (b) the two sets of the large hierarchy $R_{1a,1b,1c}$ and $R_{2a,2b,2c}$ for the ratios of the branching ratios of the considered decays are defined and can be understood in the PQCD factorization approach, while the self-consistency between the quasi-two-body and two-body framework for $B_{c} \to D_{(s)} [ρ(770) \to ] ππ$ and $B_{c} \to D_{(s)} ρ(770)$ decays are confirmed by our numerical results; (c) taking currently known ${\cal B}(ρ(1450)\toππ)$ and ${\cal B}(ρ(1700) \to ππ)$ as input, we extracted the theoretical predictions for ${\cal B}(B_{c} \to D ρ(1450)) $ and ${\cal B}(B_{c} \to D ρ(1700))$ from the PQCD predictions for the decay rates of the quasi-two-body decays $B_{c} \to D [ρ(1450), ρ(1700) \to ] ππ$. All the PQCD predictions will be tested in the future experiments.

hep-ph↗

arXiv2017

Quasi-two-body decays $B_{(s)} \to D (ρ(1450),ρ(1700)) \to D ππ$ in the perturbative QCD factorization approach

By employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach, we calculate the branching ratios of the decays $B_{(s)} \to D (ρ(1450),ρ(1700))\to D ππ$ with $D=(D_{(s)}, \bar{D}_{(s)})$. The pion vector form factor $F_π$, acquired from a {\it BABAR} Collaboration analysis of $e^+ e^- \to π^+ π^-(γ)$ data, is involved in the two-pion distribution amplitudes $Φ^{I=1}_{ππ}$. The PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the range of $10^{-10} \sim 10^{-4}$. The PQCD predictions for ${\cal B}(B^0\to \bar{D}^0 (ρ^0(1450),ρ^0(1700)) \to \bar{D}^0 π^+π^-)$ agree well with the measured values as reported by LHCb if one takes still large theoretical errors into account. Unlike the traditional way of the PQCD approach, one can extract the decay rates for the two-body decays $B_{(s)} \to D (ρ(1450),ρ(1700))$ from the results of the corresponding quasi-two-body decays. The PQCD predictions for ${\cal B}(B_{(s)} \to D ρ(1450))$ and ${\cal B}(B_{(s)} \to D ρ(770))$ are similar in magnitude: an interesting relation to be tested by future experimental measurements.

hep-ph↗

arXiv2017

Quasi-two-body decays $B \to η_c {(1S ,2S)}\;[ρ(770),ρ(1450),ρ(1700) \to ]\; ππ$ in the perturbative QCD approach

In this paper, we calculated the branching ratios of the quasi-two-body decays $B \to η_c (1S ,2S)$ $[ρ(770), ρ(1450),ρ(1700)\to ] ππ$ by employing the perturbative QCD (PQCD) approach. The contributions from the $P$-wave resonances $ρ(770)$, $ρ(1450)$ and $ρ(1700)$ were taken into account. The two-pion distribution amplitude $Φ_{ππ}^{\rm P}$ is parameterized by the vector current time-like form factor $F_π$ to study the considered decay modes. We found that (a) the PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the order of $10^{-7} \sim 10^{-6}$, while the two-body decay rates ${\cal B}(B \to η_c{(1S,2S)} (ρ(1450),ρ(1700)))$ are extracted from those for the corresponding quasi-two-body decays; (b) the whole pattern of the pion form factor-squared $|F_π|^2$ measured by the BABAR Collaboration could be understood based on our theoretical results; (c) the general expectation based on the similarity between $B \to η_c ππ$ and $B \to J/ψππ$ decays are confirmed: $R_2(η_c)\approx 0.45$ is consistent with the measured $R_2(J/ψ)\approx 0.56\pm 0.09$ within errors; and (d) new ratios $R_3(η_c(1S))$ and $R_4(η_c(2S))$ among the branching ratios of the considered decay modes are defined and could be tested by future experiments.

hep-ph↗

arXiv2017

The quasi-two-body decays $B_{(s)} \to (D_{(s)},\bar{D}_{(s)}) ρ\to (D_{(s)}, \bar{D}_{(s)})ππ$ in the perturbative QCD factorization approach

In this paper, we studied the $B_{(s)} \to (D_{(s)},\bar{D}_{(s)}) ρ\to (D_{(s)}, \bar{D}_{(s)})ππ$ decays by employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach. We use the two-pion distribution amplitudes $Φ_{ππ}$, which contains both resonant and nonresonant contributions from the pion pair, to describe the final state interactions (FSIs) between the pions in the resonant region. We found that (a) for all considered decays, the PQCD predictions for their branching ratios based on the quasi-two-body and the two-body framework agree well with each other due to ${\cal B}(ρ\to ππ) \approx 100\%$; For $B^+\to \bar{D^0}ρ^+\to \bar{D^0}π^+ π^0$ and other four considered decay modes, the PQCD predictions do agree well with the measured values within errors; (b) the great difference between the PQCD predictions for ${\cal B}(B\to \bar{D} ρ\to \bar{D} ππ)$ and ${\cal B}(B\to D ρ\to D ππ)$ can be understood by the strong CKM suppression factor $ R_{\rm CKM} \approx 3 \times 10^{-4}$; (c) for the $B_s\to D ρ\to D ππ$ and $B_s\to \bar{D} ρ\to \bar{D} ππ$ decays, however, the PQCD predictions of $R_{\rm s1}\approx 0.13$ and $R_{\rm s2}\approx 0.14$ do agree very well with the moderate CKM suppression factor $R^s_{\rm CKM}\approx 0.14$; and (d) the PQCD predictions for the ratios $R_{Dρ}$ and the strong phase difference $\cosδ_{Dρ}$ of the three $B \to \bar{D} ρ$ decay modes agree well with the LHCb measurements within one standard deviation.

hep-ph↗

arXiv2017

Quasi-two-body decays $B_{(s)}\to Pρ^\prime(1450), Pρ^{\prime\prime}(1700)\to Pππ$ in the perturbative QCD approach

In this work, we calculate the $CP$-averaged branching ratios and direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)}\to P ρ^\prime(1450), Pρ^{\prime\prime}(1700)\to P ππ$ by employing the perturbative QCD (PQCD) factorization approach, where $P$ is a light pseudoscalar meson $K, π, η$ and $η^{\prime}$. The considered decay modes are studied in the quasi-two-body framework by parameterizing the two-pion distribution amplitude $Φ_{ππ}^{\rm P}$. The $P$-wave time-like form factor $F_π$ in the resonant regions associated with the $ρ^\prime(1450)$ and $ρ^{\prime\prime}(1700)$ is estimated based on available experimental data. The PQCD predictions for the $CP$-averaged branching ratios of the decays $B_{(s)}\to Pρ^\prime(1450), Pρ^{\prime\prime}(1700)\to Pππ$ are in the order of $10^{-7} \sim 10^{-9}$. The branching ratios of the two-body decays $B_{(s)}\to Pρ^\prime(1450), Pρ^{\prime\prime}(1700)$ are extracted from the corresponding quasi-two-body decay modes. The whole pattern of the pion form factor-squared $|F_π|^2$ measured by {\it BABAR} Collaboration could also be understood based on our studies. Our PQCD predictions will be tested by the precise data from the LHCb and the future Belle II experiments.

hep-ph↗

arXiv2017

Branching ratios, $CP$ asymmetries and polarizations of $B\rightarrow ψ(2S) V$ decays

We analyzed the nonleptonic decays $B/B_s\to ψ(2S) V $ with $V=(ρ, ω, K^{*}, ϕ)$ by employing the perturbative QCD (PQCD) factorization approach. Here the branching ratios, the $CP$ asymmetries and the complete set of polarization observables are investigated systematically. Besides the traditional contributions from the factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order (NLO) vertex corrections could also provide considerable contributions. The PQCD predictions for the branching ratios of the $B_{(s)}\to ψ(2S)K^{*}, ψ(2S) ϕ$ decays are consistent with the measured values within errors. As for $B\to ψ(2S) ρ, ψ(2S) ω$ decays, the branching ratios can reach the order of $10^{-5}$ and could be measured in the LHCb and Belle-II experiments. The numerical results show that the direct $CP$ asymmetries of the considered decays are very small. Thus the observation of any large direct $CP$ asymmetry for these decays will be a signal for new physics. The mixing induced $CP$ asymmetries in the neutral modes are very close to $\sin 2β_{(s)}$, which suggests that these channels can give a cross-check on the measurement of the Cabbibo-Kobayashi-Maskawa (CKM) angle $β$ and $β_s$. We found that the longitudinal polarization fractions $f_0$ are suppressed to $\sim 50\%$ due to the large nonfactorizable contributions. The magnitudes and phases of the two transverse amplitudes $\mathcal {A}_{\parallel}$ and $\mathcal {A}_{\perp}$ are roughly equal, which is an indication for the approximate light quark helicity conservation in these decays. The overall polarization observables of $B\to ψ(2S) K^{*0}$ and $B_s\to ψ(2S) ϕ$ channels are also in good agreement with the experimental measurements as reported by LHCb and BaBar. Other results can also be tested by the LHCb and Belle-II experiments.

hep-ph↗

arXiv2017

$S$-wave resonance contributions to the $B^0_{(s)}\to η_c{(2S)}π^+π^-$ in the perturbative QCD factorization approach

By employing the perturbative QCD (PQCD) factorization approach, we study the quasi-two-body $B^0_{(s)}\to η_c{(2S)}π^+π^-$ decays, where the pion pair comes from the $S$-wave resonance $f_0(X)$. The Breit$-$Wigner formula for the $f_0(500)$ and $f_0(1500)$ resonances, and the Flatté model for the $f_0(980)$ resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes. As a comparison, Bugg's model is also used for the wide $f_0(500)$ in this work. For decay rates, we found the following PQCD predictions: (a) $ {\cal B}(B^0_s\to η_c(2S) f_0(X)[π^+π^-]_s )=\left ( 2.67^{+1.78}_{-1.08} \right )\times 10^{-5}$ when the contributions from $f_0(980)$ and $f_0(1500)$ are all taken into account; (b) ${\cal B}(B^0\to η_c(2S) f_0(500)[π^+π^-]_s)= \left ( 1.40 ^{+0.92}_{-0.56} \right ) \times 10^{-6}$ in the Breit-Wigner model and $ \left ( 1.53 ^{+0.97}_{-0.61} \right ) \times 10^{-6}$ in the Bugg's model.

hep-ph↗

arXiv2017

The S-wave resonance contributions in the $B^0_s$ decays into $ ψ(2S,3S)$ plus pion pair

The three-body decays $B^0_s \rightarrow ψ(2S,3S) π^+ π^-$ are studied based on the perturbative QCD approach. With the help of the nonperturbative two-pion distribution amplitudes, the analysis is simplified into the quasi-two-body processes. Besides the traditional factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order vertex corrections are also included to cancel the scale dependence. The $f_0(980)$, $f_0(1500)$ resonance contributions as well as the nonresonant contributions are taken into account using the presently known $ππ$ time-like scalar form factor for the $s\bar{s}$ component. It is found that the predicted $B^0_s \rightarrow ψ(2S) π^+ π^-$ decay spectra in the pion pair invariant mass shows a similar behavior as the experiment. The calculated S-wave contributions to the branching ratio of $B^0_s \rightarrow ψ(2S) π^+ π^-$ is $6.0\times 10^{-5}$, which is in agreement with the LHCb data $\mathcal {B}(B^0_s \rightarrow ψ(2S) π^+ π^-)=(7.2\pm 1.2)\times 10^{-5} $ within errors. The estimate of $\mathcal {B}(B^0_s \rightarrow ψ(3S) π^+ π^-)$ can reach the order of $10^{-5}$, pending for the corresponding measurements.

hep-ph↗

arXiv2017

Quasi-two-body decays $B_{(s)}\to Pρ\to Pππ$ in perturbative QCD approach

In this work, we calculate the $CP$-averaged branching ratios and the direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)} \to P (ρ\to) ππ$ by employing the perturbative QCD (PQCD) approach (here $P$ stands for a light pseudoscalar meson $π, K, η$ or $η^{\prime}$). The vector current time-like form factor $F_π$, which contains the final state interactions between the pion pair in the resonant region associated with the $P$-wave states $ρ(770)$ along with the two-pion distribution amplitudes, are employed to describe the interactions between the $ρ$ and the pion pair under the hypothesis of the conserved vector current. We found that (a) the PQCD predictions for the branching ratios and the direct $CP$-violating asymmetries for most considered $B_{(s)} \to P (ρ\to) ππ$ decays agree with currently available data within errors; (b) for ${\cal B}(B \to π^0 ρ^0 \to π^0(π^+ π^-)$, the PQCD prediction is much smaller than the measured one; and (c) for $B^+ \to π^+(ρ^0\to)π^+ π^-$ decay mode, we found a negative $CP$ asymmetry $(-27.5^{+3.0}_{-3.7})\%$, which agrees with other theoretical predictions but different in sign from those as reported by BaBar and LHCb Collaboration.

hep-ph↗

arXiv2017

Cost-Effective Active Learning for Deep Image Classification

Recent successes in learning-based image classification, however, heavily rely on the large number of annotated training samples, which may require considerable human efforts. In this paper, we propose a novel active learning framework, which is capable of building a competitive classifier with optimal feature representation via a limited amount of labeled training instances in an incremental learning manner. Our approach advances the existing active learning methods in two aspects. First, we incorporate deep convolutional neural networks into active learning. Through the properly designed framework, the feature representation and the classifier can be simultaneously updated with progressively annotated informative samples. Second, we present a cost-effective sample selection strategy to improve the classification performance with less manual annotations. Unlike traditional methods focusing on only the uncertain samples of low prediction confidence, we especially discover the large amount of high confidence samples from the unlabeled set for feature learning. Specifically, these high confidence samples are automatically selected and iteratively assigned pseudo-labels. We thus call our framework "Cost-Effective Active Learning" (CEAL) standing for the two advantages.Extensive experiments demonstrate that the proposed CEAL framework can achieve promising results on two challenging image classification datasets, i.e., face recognition on CACD database [1] and object categorization on Caltech-256 [2].

cs.CV↗

arXiv2016

The $S$-wave resonance contributions to the three-body decays $B^0_{(s)}\to η_c f_0(X)\to η_cπ^+π^-$ in perturbative QCD approach

In this paper, we study the three-body decays $B^0/B^0_s \to η_c f_0(X)\to η_c π^+π^-$ by employing the perturbative QCD (PQCD) factorization approach. We evaluate the $S$-wave resonance contributions by using the two-pion distribution amplitude $Φ_{ππ}^{\rm S}$. The Breit-Wigner formula for the $f_0(500)$, $f_0(1500)$, and $f_0(1790)$ resonances and the Flatté model for the $f_0(980)$ resonance are adopted to parameterize the time-like scalar form factors $F_{s}(ω^2)$. We also use the D.~V.~Bugg model to parameterize the $f_0(500)$ and compare the relevant theoretical predictions from different models. We found the following results: (a) the PQCD predictions for the branching ratios are ${\cal B}(B^0\to η_c f_0(500)[π^+π^-])= \left ( 1.53 ^{+0.76}_{-0.35} \right ) \times 10^{-6}$ for Breit-Wigner model and ${\cal B}(B^0\to η_c f_0(500)[π^+π^-])= \left ( 2.31 ^{+0.96}_{-0.48} \right ) \times 10^{-6}$ for D.~V.~Bugg model; (b) $ {\cal B}(B_s\to η_c f_0(X)[π^+π^-] ) =\left ( 5.02^{+1.49}_{-1.08} \right )\times 10^{-5}$ when the contributions from $f_0(X)=(f_0(980),f_0(1500),f_0(1790))$ are all taken into account; and (c) The considered decays could be measured at the ongoing LHCb experiment, consequently, the formalism of two-hadron distribution amplitudes could also be tested by such experiments.

hep-ph↗