Post-hoc interpretability approaches have been proven to be powerful tools to generate explanations for the predictions made by a trained black-box model. However, they create the risk of having explanations that are a result of some artifacts learned by the model instead of actual knowledge from the data. This paper focuses on the case of counterfactual explanations and asks whether the generated instances can be justified, i.e. continuously connected to some ground-truth data. We evaluate the risk of generating unjustified counterfactual examples by investigating the local neighborhoods of instances whose predictions are to be explained and show that this risk is quite high for several datasets. Furthermore, we show that most state of the art approaches do not differentiate justified from unjustified counterfactual examples, leading to less useful explanations.

Model checking of temporal logics in a well established technique to verify and validate properties of multi-agent systems (MAS). However, practical model checking requires input models of manageable size. In this paper, we extend the model reduction method by variable-based abstraction, proposed recently by Jamroga and Kim, to the verification of real-time systems and properties. To this end, we define a real-time extension of MAS graphs, extend the abstraction procedure, and prove its correctness for the universal fragment of Timed Computation Tree Logic (TCTL). Besides estimating the theoretical complexity gains, we present an experimental evaluation for a simplified model of the Estonian voting system and verification using the Uppaal model checker.

Heavy-flavour physics is an essential component of the particle-physics programme, offering critical tests of the Standard Model and far-reaching sensitivity to physics beyond it. Experiments such as LHCb, Belle II, and BESIII drive progress in the field, along with contributions from ATLAS and CMS. The LHCb Upgrade II and upgraded Belle II experiments will provide unique and highly sensitive measurements for decades, playing a key role in the searches for new physics. Future facilities with significant heavy-flavour capabilities will further expand these opportunities. We advocate for a European Strategy that fully supports Upgrade II of LHCb and an upgrade of Belle II, along with their subsequent exploitation. Additionally, we support a long-term plan that fully integrates flavour physics in an $e^+e^-$ collider to run as a $Z$ factory.

Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ ($\ell=e,\mu$) are predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb$^{-1}$, is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions, $\mathcal{B}(\tau^{\pm}\rightarrow \mu^{\pm}\gamma)$ $\leq$ $4.2\times10^{-8}$ and $\mathcal{B}(\tau^{\pm}\rightarrow e^{\pm}\gamma)$ $\leq$ $5.6\times10^{-8}$, are set at 90\% confidence level.

We search for $CP$ violation in the charged charm meson decay $D^{+}\to\pi^{+}\pi^{0}$, based on a data sample corresponding to an integrated luminosity of $\rm 921~fb^{-1}$ collected by the Belle experiment at the KEKB $e^{+}e^{-}$ asymmetric-energy collider. The measured $CP$ violating asymmetry is $[+2.31\pm1.24({\rm stat})\pm0.23({\rm syst})]\%$, which is consistent with the standard model prediction and has a significantly improved precision compared to previous results.

We report a high-statistics measurement of the branching fraction for tau^- --> pi^- pi^0 nu_tau and the invariant mass spectrum of the produced pi^- pi^0 system using 72.2 fb^-1 of data recorded with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. The branching fraction obtained is (25.24 +/- 0.01 +/- 0.39)%, where the first error is statistical and the second is systematic. The unfolded pi^- pi^0 mass spectrum is used to determine resonance parameters for the rho(770), rho'(1450), and rho"(1700) mesons. We also use this spectrum to estimate the hadronic (2pi) contribution to the anomalous magnetic moment of the muon (a_{mu}^{pipi}). Our result for a_{mu}^{pipi} integrated over the mass range sqrt{s} = 2m_{pi} - 1.8 GeV/c^2 is a_{mu}^{pipi} = (523.5 +/- 1.5 (exp) +/- 2.6 (Br) +/- 2.5 (isospin))x 10^{-10}, where the first error is due to the experimental uncertainties, the second is due to the uncertainties in the branching fractions and the third is due to the uncertainties in the isospin-violating corrections.

We present measurements of B+ -> Dbar*0 tau+ nu_tau and B+ -> Dbar^0 tau+ nu_tau decays in a data sample of 657 x 10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find 446^{+58}_{-56} events of the decay B+ -> Dbar*0 tau+ nu_tau with a significance of 8.1 standard deviations, and 146^{+42}_{-41} events of the decay B+ -> Dbar0 tau+ nu_tau with a significance of 3.5 standard deviations. The latter signal provides the first evidence for this decay mode. The measured branching fractions are B(B+ -> Dbar*0 tau+ nu_tau)=(2.12^{+0.28}_{-0.27} (stat) +- 0.29 (syst)) % and B(B+ -> Dbar0 tau+ nu_tau)=(0.77 +- 0.22 (stat) +- 0.12 (syst)) %.

The dark photon, $A^\prime$, and the dark Higgs boson, $h^\prime$, are hypothetical constituents featured in a number of recently proposed Dark Sector Models. Assuming prompt decays of both dark particles, we search for their production in the so-called Higgs-strahlung channel, $e^+e^- \rightarrow A^\prime h'$, with $h^\prime \rightarrow A^\prime A^\prime$. We investigate ten exclusive final-states with $A^\prime \rightarrow e^+e^-$, $\mu^+\mu^-$, or $\pi^+\pi^-$, in the mass ranges $0.1$~GeV/$c^2$~< m_{A^\prime} < 3.5~GeV/$c^2$ and $0.2$~GeV/$c^2$~< m_{h'} < 10.5~GeV/$c^2$. We also investigate three inclusive final-states, $2(e^+e^-)X$, $2(\mu^+\mu^-)X$, and $(e^+e^-)(\mu^+\mu^-)X$, where $X$ denotes a dark photon candidate detected via missing mass, in the mass ranges $1.1$~GeV/$c^2$~< m_{A^\prime} < 3.5~GeV/$c^2$ and $2.2$~GeV/$c^2$~< m_{h'} < 10.5~GeV/$c^2$. Using the entire $977\,\mathrm{fb}^{-1}$ data set collected by Belle, we observe no significant signal. We obtain individual and combined 90$\%$ confidence level upper limits on the branching fraction times the Born cross section, $\cal B \times \sigma_{\mathrm{Born}}$, on the Born cross section, $\sigma_{\mathrm{Born}}$, and on the dark photon coupling to the dark Higgs boson times the kinetic mixing between the Standard Model photon and the dark photon, $\alpha_D \times \epsilon^2$. These limits improve upon and cover wider mass ranges than previous experiments. The limits from the final-states $3(\pi^+\pi^-)$ and $2(e^+e^-)X$ are the first placed by any experiment. For $\alpha_D$ equal to 1/137, m_{h'}< 8 GeV/$c^2$, and m_{A^\prime}< 1 GeV/$c^2$, we exclude values of the mixing parameter, $\epsilon$, above $\sim 8 \times 10^{-4}$.

Polarization effects in the production of antiprotons at the CERN PS beam line T11 at 3.5 GeV/c have been investigated within the P371 experiment. These effects, if found to be significant could provide a simple method to generate polarized antiproton beams with existing facilities. First precursor measurements were carried out by the P349 collaboration, though the available statistics were insufficient for a quantitative conclusion. With an upgraded detector setup and extended beam time, the experiment aims at determining whether a measurable degree of antiproton polarization exists.

We report the observation of two narrow structures in the mass spectra of the pi+-Y(nS) (n=1,2,3) and pi+-hb(mP)(m$ (m=1,2) pairs that are produced in association with a single charged pion in Y(5S) decays. The measured masses and widths of the two structures averaged over the five final states are M_1=(10607.2+-2.0) MeV/c2, Gamma_1=(18.4+-2.4) MeV and M_2=(10652.2+-1.5) MeV/c2, Gamma_2=(11.5+-2.2) MeV. The results are obtained with a 121.4 1/fb data sample collected with the Belle detector in the vicinity of the Y(5S) resonance at the KEKB asymmetric-energy e+e- collider.

The Silicon Vertex Detector of Belle II is a state-of-the-art tracking and vertexing system based on double-sided silicon strip sensors, designed and fabricated by a large international collaboration in the period 2012--2018. Since 2019 it has been in operation providing high quality data with a small number of defective channels (<1%), a large hit-finding efficiency (>99%), a good signal-to-noise ratio (well in excess of 10 for all sensor configurations and tracks). Together with the good control over the alignment, these are all essential factors to achieve good tracking reconstruction and physics performance. In this extended paper we try to document all the aspects of the SVD challenges and achievements, in the spirit of providing information to the broader community and help the development of high quality detector systems, which are fundamental tools to carry out physics research.

We search for lepton-flavor-violating tau-> ell V^0 decays, where ell is an electron or muon and V^0 is one of the vector mesons rho^0, phi, omega, K*0 and K*0-bar. We use 854 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. No evidence for a signal is found in any decay mode, and we obtain 90% confidence level upper limits on the individual branching fractions in the range (1.2-8.4)*10^{-8}.

We report measurements of branching fractions of $\tau$ lepton decays to final states with a $K^{0}_{S}$ meson using a 669 fb$^{-1}$ data sample accumulated with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. The inclusive branching fraction is measured to be $\mathcal{B}(\tau^{-} \to K^{0}_{S}\ X^{-} \nu_{\tau})=(9.15 \pm 0.01 \pm 0.15) \times 10^{-3}$, where $X^{-}$ can be anything; the exclusive branching fractions are $\mathcal{B}(\tau^{-} \to \pi^{-} K^{0}_{S} \nu_{\tau}) = (4.16 \pm 0.01 \pm 0.08) \times 10^{-3}$, $\mathcal{B}(\tau^{-} \to K^{-} K^{0}_{S} \nu_{\tau}) = (7.40 \pm 0.07 \pm 0.27) \times 10^{-4}$, $\mathcal{B}(\tau^{-} \to \pi^{-} K^{0}_{S} \pi^{0} \nu_{\tau}) = (1.93 \pm 0.02 \pm 0.07) \times 10^{-3}$, $\mathcal{B}(\tau^{-} \to K^{-} K^{0}_{S} \pi^{0} \nu_{\tau}) = (7.48 \pm 0.10 \pm 0.37)\times 10^{-4}$, $\mathcal{B}(\tau^{-} \to \pi^{-} K^{0}_{S} K^{0}_{S} \nu_{\tau}) = (2.33 \pm 0.03 \pm 0.09) \times 10^{-4}$, $\mathcal{B}(\tau^{-} \to \pi^{-} K^{0}_{S} K^{0}_{S} \pi^{0} \nu_{\tau}) = (2.00 \pm 0.22 \pm 0.20) \times 10^{-5}$, where the first uncertainty is statistical and the second is systematic. For each mode, the accuracy is improved over that of pre-$B$-factory measurements by a factor ranging from five to ten. In $\tau^{-} \to \pi^{-} K^0_S K^0_S \pi^{0} \nu_{\tau}$ decays, clear signals for the intermediate states $\tau^{-} \to \pi^- f_{1}(1285)\nu_{\tau}$ and $\tau^{-} \to K^{*-}K^{0}_{S} \pi^{0} \nu_{\tau}$ are observed.

We report measurements of the branching fractions for $B^0\to\pi^+\pi^-$, $K^+\pi^-$, $K^+K^-$ and $K^0\pi^0$, and $B^+\to\pi^+\pi^0$, $K^+\pi^0$, $K^0\pi^+$ and $K^+\bar{K}{}^0$. The results are based on 10.4 fb$^{-1}$ of data collected on the $\Upsilon$(4S) resonance at the KEKB $e^+e^-$ storage ring with the Belle detector, equipped with a high momentum particle identification system for clear separation of charged $\pi$ and $K$ mesons. We find ${\cal B}(B^0\to\pi^+\pi^-) =(0.56^{+0.23}_{-0.20}\pm 0.04)\times 10^{-5}$,${\cal B}(B^0\to K^+\pi^-) =(1.93^{+0.34 +0.15}_{-0.32 -0.06})\times 10^{-5}$,${\cal B}(B^+\to K^+\pi^0) =(1.63^{+0.35 +0.16}_{-0.33 -0.18})\times 10^{-5}$,${\cal B}(B^+\to K^0\pi^+) =(1.37^{+0.57 +0.19}_{-0.48 -0.18})\times 10^{-5}$, and${\cal B}(B^0\to K^0\pi^0) =(1.60^{+0.72 +0.25}_{-0.59 -0.27})\times 10^{-5}$, where the first and second errors are statistical and systematic. We also set upper limits of ${\cal B}(B^+\to\pi^+\pi^0)<1.34\times 10^{-5}$,${\cal B}(B^0\to K^+K^-)<0.27\times 10^{-5}$, and${\cal B}(B^+\to K^+\bar{K}{}^0)<0.50\times 10^{-5}$ at the 90% confidence level.

The differential cross sections for the process $\gamma \gamma \to \pi^0 \pi^0$have been measured in the kinematic range 0.6 GeV$< W < 4.1$ GeV, |\cos \theta^*|&lt;0.8 in energy and pion scattering angle, respectively, in the $\gamma\gamma$ center-of-mass system. The results are based on a 223 fb$^{-1}$ data sample collected with the Belle detector at the KEKB $e^+ e^-$ collider. The differential cross sections are fitted in the energy region 1.7 GeV &lt; W &lt; 2.5 GeV to confirm the two-photon production of two pions in the G wave. In the higher energy region, we observe production of the $\chi_{c0}$ charmonium state and obtain the product of its two-photon decay width and branching fraction to $\pi^0\pi^0$. We also compare the observed angular dependence and ratios of cross sections for neutral-pion and charged-pion pair production to QCD models. The energy and angular dependence above 3.1 GeV are compatible with those measured in the $\pi^+\pi^-$ channel, and in addition we find that the cross section ratio, $\sigma(\pi^0\pi^0)/\sigma(\pi^+\pi^-)$, is $0.32 \pm 0.03 \pm 0.05$ on average in the 3.1-4.1 GeV region.

Gateway Servers for the Internet of Vehicles (IoV) must meet stringent Security and Quality of Service (QoS) requirements, including cyberattack protection, low delays and minimal packet loss, to offer secure real-time data exchange for human and vehicle safety and efficient road traffic management. Therefore, it is vital to protect these systems from cyberattacks with adequate Attack Detection (AD) and Mitigation mechanisms. Such attacks often include packet Floods that impair the QoS of the networks and Gateways and even impede the Gateways capability to carry out AD. Thus, this paper first evaluates these effects using system measurements during Flood attacks. It then demonstrates how a Smart Quasi-Deterministic Policy Forwarder (SQF) at the entrance of the Gateway can regulate the incoming traffic to ensure that the Gateway supports the AD to operate promptly during an attack. Since Flood attacks create substantial packet backlogs, we propose a novel Adaptive Attack Mitigation (AAM) system that is activated after an attack is detected to dynamically sample the incoming packet stream, determine whether the attack is continuing, and also drop batches of packets at the input to reduce the effects of the attack. The AAM is designed to minimize a cost function that includes the sampling overhead and the cost of lost benign packets. We show experimentally that the Optimum AAM approach is effective in mitigating attacks and present theoretical and experimental results that validate the proposed approach.

As Machine Learning (ML) models achieve unprecedented levels of performance, the XAI domain aims at making these models understandable by presenting end-users with intelligible explanations. Yet, some existing XAI approaches fail to meet expectations: several issues have been reported in the literature, generally pointing out either technical limitations or misinterpretations by users. In this paper, we argue that the resulting harms arise from a complex overlap of multiple failures in XAI, which existing ad-hoc studies fail to capture. This work therefore advocates for a holistic perspective, presenting a systematic investigation of limitations of current XAI methods and their impact on the interpretation of explanations. By distinguishing between system-specific and user-specific failures, we propose a typological framework that helps revealing the nuanced complexities of explanation failures. Leveraging this typology, we also discuss some research directions to help AI practitioners better understand the limitations of XAI systems and enhance the quality of ML explanations.

We report the first observation of the charmless vector-vector decay process B+ ->rho+ rho0. The measurement uses a 78 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric e+e- collider operating at the Upsilon(4S) resonance. We obtain a branching fraction of Br(B+ ->rho+ rho0)=(31.7+-7.1(stat.)+3.8-6.7(sys.))*10^{-6}. An analysis of the rho helicity-angle distributions gives a longitudinal polarization of Gamma_{L}/Gamma=(94.8+-10.6(stat.)+-2.1(sys.))%.