Search

The investigation of charm physics plays an important role in checking the Standard Model’s description of strong and weak interactions, validating its predictions for particle physics, and exploring new physics beyond the Standard Model. Using a large dataset from e+e− annihilation, BESIII has conducted comprehensive and extensive studies in the areas of hadronic, leptonic and semileptonic decays. This proceeding presents an overview of the recent researches and discoveries by BESIII on decays of charmed baryons, charmed mesons and charmonium states, highlighting their significance in advancing the understanding of new physics, experimental determination of physical parameters and improvement of measurement precision. [ABSTRACT FROM AUTHOR]

Accelerator searches for new resonances have a long-standing history of discoveries that have driven advances in our understanding of nature. Since 2010, the Large Hadron Collider (LHC) has probed previously inaccessible energy scales, enabling searches for new heavy resonances predicted by a wide range of theories beyond the Standard Model (BSM). In particular, resonance decays into fermionic final states are often seen as golden channels since they provide a clear signal—typically a peak in the invariant mass of the decay products over a smoothly falling background distribution. This review summarizes the key concepts of the experimental searches for new resonances decaying to fermions, in the context of the BSM theories that motivate them, and presents the latest results of the ATLAS and CMS experiments, focusing on the complete LHC Run 2 dataset. Future prospects at the High-Luminosity LHC and potential future colliders are also surveyed. [ABSTRACT FROM AUTHOR]

Experimental activities involving multi-TeV muon collisions are a relatively recent endeavor. The community has limited experience in designing detectors for lepton interactions at center-of-mass energies of 10 TeV and beyond. This review provides a short overview of the machine characteristics and outlines potential sources of beam-induced background that could affect the detector performance. The strategy for mitigating the effects of the beam-induced background on the detector at TeV is discussed with a focus on the machine–detector interface, detector design, and implementation of reconstruction algorithms. The physics potential at this center-of-mass energy is evaluated using a detailed detector simulation that incorporates the effects of the beam-induced background. This evaluation concerns the Higgs boson couplings and the Higgs field potential sensitivity, which then are used to obtain confidence on the expectations at 10 TeV. The physics and detector requirements for an experiment at TeV, outlined here, form the foundation for the initial detector concept at that center-of-mass energy. [ABSTRACT FROM AUTHOR]

Silk damping is well known in the study of cosmic microwave background (CMB) and accounts for suppression of the angular power spectrum of CMB on large angular multipoles. In this article, we study the effect of Silk damping on the scalar-induced gravitational waves (SIGWs). Resulting from the dissipation of cosmic fluid, the Silk damping notably suppresses the energy-density spectrum of SIGWs on scales comparable to a diffusion scale at the decoupling time of weakly-interacting particles. The effect offers a novel observable for probing the underlying particle interaction, especially for those mediated by heavy gauge bosons beyond the standard model of particles. We anticipate that pulsar timing arrays are sensitive to gauge bosons with mass ∼ 103–104 GeV, while space- and ground-based interferometers to those with mass ∼ 107–1012 GeV, leading to essential complements to on-going and future experiments of high-energy physics. [ABSTRACT FROM AUTHOR]

Heavy neutral gauge boson Z′ is proposed in many new physics models. It has rich phenomena at the future muon collider. We study the properties of Z′ boson with the process of and μ+μ− → W+W−. The discrepancy of Z′ coupling to different types of particles can be shown in the cross section distributions around the resonance peak of various decay modes. Angular distributions of the final quark or lepton in process are sensitive to the parameters such as mass of Z′ and the Z − Z′ mixing angle. The interaction of new gauge boson coupling to the standard model gauge particles and Higgs boson are also studied through and . The cross section and the final particles' angular distributions with the contribution of Z′ boson differ from those processes with only standard model particles. A forward-backward asymmetry defined by the angular distribution is provided to show the potential of searching for new physics at the muon collider. Especially, the beam polarization with certain value can effectively enlarge the forward-backward asymmetry. [ABSTRACT FROM AUTHOR]

The aim of the proposed CERN Gamma Factory is to produce ≈1017 photons per second with energies up to 400 MeV. The photon beam intensity is expected to be a factor of (Formula presented.) larger than that of the presently available photon beams in the MeV energy range. In this work, its potential to probe physics beyond the Standard Model is explored. In particular, searches for axion like particles (ALPs) with dominant couplings to photons are discussed and various production scenarios—fixed target, photon–photon collision, and conversion by a magnetic field—and detection schemes considered—via decay to photons or back-conversion. It is found that the Gamma Factory in a fixed target mode can probe ALPs with mass (Formula presented.) and decay constants larger than 107 GeV, improving by an order of magnitude the discovery potential of previous beam dump experiments.

In recent times, there have been several observations suggesting deviations from lepton universality in semileptonic decays of B mesons. These deviations have been noticed both in the neutral-current transitions (b → s l l) and charged-current transitions (b → c l ν ̄ l ). Motivated by these intriguing findings, we investigate the semileptonic decays involving the quark-level transitions of b → c l ν ̄ l . To explore the presence of new physics, we adopt a model-independent approach and analyze the processes Λ b → Λ c τ ν ̄ τ , B c + → η c τ + ν τ and B → D ∗ ∗ τ ν ̄ τ , where D ∗ ∗ = D 0 ∗ , D 1 ∗ , D 1 , D 2 ∗ represent the four lightest excited charm mesons. Considering a comprehensive effective Hamiltonian, we perform a global fit using various sets of new coefficients and incorporate measurements of R D , R D ∗ , R J ∕ ψ , P τ D ∗ , as well as the upper limit on the branching ratio of B c + → τ + ν τ . Subsequently, we examine the impact of constrained new couplings on the branching ratios, forward–backward asymmetry parameters, lepton nonuniversality (LNU) ratios, as well as lepton and hadron polarization asymmetries in these decay modes. [ABSTRACT FROM AUTHOR]

Lepton flavor universality exists in the Standard Model, and hence any observation of the violation of this universality will be a hint for new physics. Recent experimental searches for processes violating this symmetry have attracted much attention among theorists and experimentalists alike. In recent years, such hints have been observed in flavor changing neutral current weak processes such as b → s l l and charged current weak processes such as b → c l ν processes by collider experiments like Belle, Belle II, BaBar, LHCb, ATLAS, and CMS collaborations, where b , s , c are the bottom, strange, and charm quarks, respectively, and l , ν stand for lepton and the corresponding lepton neutrino, respectively. This article is a review of some of the interesting anomalies observed in the B-sector and includes decays of B s mesons. [ABSTRACT FROM AUTHOR]

The rare decays, K+→π+νν¯, B+→π+νν¯ and D+→π+νν¯, are investigated in the frame work of nonstandard neutrino interactions (NSI). It is claimed that NSI are arising due to non-universality of the leptons and bounds on NSI parameters ϵll‧uL are determined. For this purpose, the branching ratios (Br) of these processes with in the Standard Model (SM) and beyond the SM are calculated by applying the non-universality of the leptons. The NSI in K+→π+νν¯ and B+→π+νν¯ proceed with u quark in the loop while other two with d quark in the loop. Very stringent 1 σ level constrains on non-standard parameters (ϵττuL and ϵτl‧uL) are pointed out. [ABSTRACT FROM AUTHOR]

In this article, I review scenarios of physics beyond the Standard Model in which the top quark plays a special role. Models that aim at the stabilization of the weak scale are presented together with the specific phenomenology of partner states that are characteristic of this type of model. Further, I present models of flavor in which the top quark is singled out as a special flavor in the Standard Model. The flavor and collider phenomenology of these models is broadly presented. Finally, I discuss the possibility that dark matter interacts preferably with the top quark flavor and give an overview of the dark matter phenomenology of these scenarios, as well as collider and flavor signals. [ABSTRACT FROM AUTHOR]

Asymptotic safety is a remarkable example when fruitful ideas borrowed from statistical physics proliferate to high-energy physics. The concept of asymptotic safety is tightly connected to fixed points (FPs) of the renormalization-group (RG) flow, and generalize well-known asymptotic freedom to a scale-invariant ultraviolet completion with non-vanishing interactions. In this review, we discuss the key ideas behind asymptotic safety, a mechanism for achieving it, and the conditions it imposes on general gauge–Yukawa field theories. We also pay special attention to possible phenomenological applications and provide an overview of standard model (SM) extensions potentially exhibiting asymptotic safety. [ABSTRACT FROM AUTHOR]

We implement the χ 2 fit for R (K (∗)) with possible tree-level new physics in a model-independent parametrization. Relevant Wilson coefficients are decomposed into the new physics scale, its power, and the fermionic couplings. Constraints from the branching ratio of B s → μ + μ − can be naturally incorporated with the scheme. For a reasonable set of the parameter ranges it is found that the new physics is less than ∼ 5 TeV. Some new physics models including the leptoquark, Z ′ , etc. can be embraced within our framework. We give comments on new LHCb data which are close to the standard model predictions. [ABSTRACT FROM AUTHOR]

This study aims to reveal that all religion-science debates, which deal with religion and science in a comparative way, present them as alternatives to each other and show the two sides as if they are in competition, are essentially fictional. This debate, which emerged as a reflex against the discourses produced about the religion-science relations in the Middle Ages after the scientific revolution and modern thought in the West, took place in different forms in the Islamic world. However, we observe that almost all of the discourses produced in this way take place in a way that accepts the authority of science and centers science by affirming all aspects. In other words, in the religion-science debate that took place after the aforementioned periods, science has always been defined as a legitimate field that is not open to discussion, and religious discourse has been compelled to act in accordance with the scientific data of the period. In such an approach, science is elevated to a position that expresses the absolute truth in every situation, and religion is forced to comply with this exemplary institution of truth. However, some changes in the world of science in the last century show that science does not actually provide us with the perfect truth, that scientific data is accepted according to periodic usefulness, and these acceptances are also affected by some personal and social factors. That is, science does not offer us objective reality, but the practical form in which reality is perceived in our minds. The most influential theory that reveals that science is not perfect and does not have absolute objectivity and certainty is Thomas S. Kuhn's theory of paradigms. With this theory, Kuhn revealed the invalidity of the claims of infallibility and immutability imposed on them, without devaluing scientific claims and without falling into a rigid subjectivism, and laid the foundations of a new view towards science, parallel to the shaking of the idea of unlimited trust in reason in philosophy. Some other developments in the world of science also show us that scientific data is always open to change. So, equating science with religion, which is a field of discourse that is open to being affected by periodic and personal conditions and therefore dependent on change, will be a problematic approach in terms of the universal claims of religion. In order to overcome this problem, the borders of religion and science should be well drawn, and the point at which these two fields can come together should be clearly revealed. As a result of this effort, it will be understood that religion and science are two different fields that do not aim to offer alternatives to each other. In other words, a scientific data should never be put into discussion with the data of religion. This situation does not seem possible from a theoretical and methodological point of view. For example, by combining the theory of evolution, which is a scientific claim, with religions' narratives of creation, to initiate a debate between religion and science, or to declare one of the two claims true and the other false; It will mean that religion, which aims to make a statement about the subject, is put into a fictional struggle. Or, by juxtaposing a narrative about the history of the prophets with the claims of the science of history, to seek support from the science of history or to conclude that there is an inconsistency between them would be to force two distant claims together. Religious texts are not the ground on which the accuracy of scientific claims about the formation of humanity will be checked. Or the narratives about the first man in religious texts should not be considered as the thesis or antithesis of a scientific claim. In this study, based on Thomas S. Kuhn's views on the extent to which scientific claims can represent absolute truth, we argue that the fact that religion and science, which have different goals, are presented in competition as alternatives to each other, is not actually compatible with the essence of both fields, that is, between religion and science. We aim to justify that the alleged debates or tensions are actually fictions that have no reality. [ABSTRACT FROM AUTHOR]

The Ricochet reactor neutrino observatory is planned to be installed at Institut Laue–Langevin starting in mid-2022. The scientific goal of the Ricochet collaboration is to perform a low-energy and percentage precision CENNS measurement in order to explore exotic physics scenarios beyond the standard model. To that end, Ricochet will host two cryogenic detector arrays: the CryoCube (Ge target) and the Q-ARRAY (Zn target), both with unprecedented sensitivity to O (10) eV nuclear recoils. The CryoCube will be composed of 27 Ge crystals of 38 g instrumented with NTD-Ge thermal sensor as well as aluminum electrodes operated at 10 mK in order to measure both the ionization and the heat energies arising from a particle interaction. To be a competitive CENNS detector, the CryoCube array is designed with the following specifications: a low-energy threshold ( ∼ 50 eV), the ability to identify and reject with a high efficiency the overwhelming electromagnetic backgrounds (gamma, beta, and X-rays), and a sufficient payload ( ∼ 1 kg). After a brief introduction of the future Ricochet experiment and its CryoCube, the current works and first performance results on the optimization of the heat channel, and the electrode designs will be presented. We conclude with a preliminary estimation of the CryoCube sensitivity to the CENNS signal within Ricochet. [ABSTRACT FROM AUTHOR]

Behind succeeding measurements of anomalies in semileptonic decays at LHCb and several collider experiments hinting at the possible violation of lepton flavor universality, we undertake a concise review of theoretical foundations of the tree- and loop-level b-hadron decays, b → c l ν l and b → s l + l − along with experimental environments. We revisit the world averages for R D (D *) , R K (K *) , R J / ψ , and R η c , for the semileptonic transitions and provide results within the framework of the relativistic independent quark model in addition to the results from model-independent studies. If the ongoing evaluation of the data of LHC Run 2 confirms the measurements of Run 1, then the statistical significance of the effect in each decay channel is likely to reach 5 σ. A confirmation of these measurements would soon turn out to be the first remarkable observation of physics beyond the Standard Model, providing a wider outlook on the understanding of new physics. [ABSTRACT FROM AUTHOR]

We propose a new model independent technique for constructing background data templates for use in searches for new physics processes at the LHC. This method, called Curtains, uses invertible neural networks to parameterise the distribution of side band data as a function of the resonant observable. The network learns a transformation to map any data point from its value of the resonant observable to another chosen value. Using Curtains, a template for the background data in the signal window is constructed by mapping the data from the side-bands into the signal region. We perform anomaly detection using the Curtains background template to enhance the sensitivity to new physics in a bump hunt. We demonstrate its performance in a sliding window search across a wide range of mass values. Using the LHC Olympics dataset, we demonstrate that Curtains matches the performance of other leading approaches which aim to improve the sensitivity of bump hunts, can be trained on a much smaller range of the invariant mass, and is fully data driven.

We propose to investigate the effects of new physics in the semi-leptonic sequential decay Λ b → Λ c (→ Λ π) τ ν ̄ τ . First, we write the general, model-independent, non-covariant expression of the differential decay width of the process. Then, we calculate that observable according to three different types of new physics interactions, which might explain the tension of data with the Standard Model predictions. We find that some coefficients of the differential decay width are sensitive to the kind of interaction that is assumed. The measurements that we suggest seem to be feasible. [ABSTRACT FROM AUTHOR]

Construction of future Muon Collier (or dedicated μ -ring) tangential to the energy frontier h h colliders will give opportunity to realize μ p and μ A collisions at multi-TeV center-of-mass energies with sufficiently high luminosities. Obviously, such colliders will essentially enlarge the physics search potential of corresponding muon and hadron colliders for both the SM (especially for clarifying QCD basics and confinement hypothesis) and BSM phenomena. In addition, they will provide parton distribution functions for adequate interpretation of energy frontier h h colliders' and cosmic ray experiments data. This paper is devoted to review of main parameters of μ h colliders proposed until now. [ABSTRACT FROM AUTHOR]

Lepton flavor universality exists in the Standard Model, and hence any observation of the violation of this universality will be a hint for new physics. Recent experimental searches for processes violating this symmetry have attracted much attention among theorists and experimentalists alike. In recent years, such hints have been observed in flavor changing neutral current weak processes such as b→sll and charged current weak processes such as b→clν processes by collider experiments like Belle, Belle II, BaBar, LHCb, ATLAS, and CMS collaborations, where b,s,c are the bottom, strange, and charm quarks, respectively, and l,ν stand for lepton and the corresponding lepton neutrino, respectively. This article is a review of some of the interesting anomalies observed in the B-sector and includes decays of Bs mesons.

Abstract Dielectric metamaterials based on ceramics have attracted considerable interest in the past few years owing to their low dielectric loss, simple structure, excellent multifield tunability, and good environmental adaptability. They are considered to be promising alternative to metal‐based metamaterials and can lead to a new strategy for the development of passive devices. In this review, the recent progress of ceramic‐based dielectric metamaterials in electromagnetic applications, energy applications, non‐Hermitian systems, and natural materials with near‐zero or negative refraction are summarized. The design principle and mechanism, as well as manufacturing technologies, are also introduced, and the current development trend of ceramic‐based dielectric metamaterials are proposed.

We present an overview of searches for violation of lepton flavor universality with a focus on low energy precision probes using π, K, τ, and nuclear beta decays. We review the current experimental results, summarize the theoretical status within the context of the Standard Model, and discuss future prospects (both experimental and theoretical). We review the implications of these measurements for physics beyond the Standard Model by performing a global model-independent fit to modified W couplings to leptons and four-fermion operators. We also discuss new physics in the context of simplified models and review Standard Model extensions with a focus on those that can explain a possible deviation from unitarity of the Cabibbo–Kobayashi–Maskawa quark mixing matrix. [ABSTRACT FROM AUTHOR]

At the present time (2022), there are discrepancies with the predictions of the Standard Model in several observables involving b → sℓ+ℓ− and decays. These are the B flavor anomalies. In this review, we summarize the data as of Moriond 2021 and present theoretical new physics explanations from both a model-independent effective field theory point of view and through the building of explicit models. Throughout, we stress the complementarity of these two approaches. In addition, we discuss combined explanations of both B anomalies and present models that also explain other problems, such as dark matter, (g − 2)μ, neutrino properties, and hadronic anomalies. [ABSTRACT FROM AUTHOR]

In the past decade, electroweak penguin decays have provided a number of precision measurements and have become one of the most competitive ways to search for New Physics describing phenomena beyond the Standard Model. An overview of the measurements made at the B factories and hadron colliders is given, and the experimental methods are presented. Experimental measurements required to provide further insight into present indications of New Physics are discussed. [ABSTRACT FROM AUTHOR]

The very precise measurement of the anomalous magnetic moment of the muon, recently released by the Muon g-2 experiment at Fermilab, can serve to set stringent constraints on new particles. If the observed 4σ discrepancy from the Standard Model value is indeed real, it will set a tight margin on the scale of the masses and couplings of these particles. Instead, if the discrepancy is simply a result of additional theoretical and experimental uncertainties to be included, strong constraints can be put on their parameters. In this mini-review, we summarize the impact of the latest muon g-2 measurement on new fermions that are predicted by a wide range of new physics models and with exotic quantum numbers and interactions. We will particularly discuss the case of vector-like leptons, excited leptons, and supersymmetric fermions, as well as spin-3/2 isosinglet fermions, which have been advocated recently.

Asymptotic safety is a remarkable example when fruitful ideas borrowed from statistical physics proliferate to high-energy physics. The concept of asymptotic safety is tightly connected to fixed points (FPs) of the renormalization-group (RG) flow, and generalize well-known asymptotic freedom to a scale-invariant ultraviolet completion with non-vanishing interactions. In this review, we discuss the key ideas behind asymptotic safety, a mechanism for achieving it, and the conditions it imposes on general gauge–Yukawa field theories. We also pay special attention to possible phenomenological applications and provide an overview of standard model (SM) extensions potentially exhibiting asymptotic safety.

We consider extensions of the standard model (SM) with neutral scalars in multiplets of SU (2) larger than doublets. When those scalars acquire vacuum expectation values, the resulting masses of the gauge bosons W ± and Z 0 are not related by m W = m Z  cos  θ W . In those extensions of the SM the oblique parameters S and U, when computed at the one-loop level, turn out to be either gauge-dependent or divergent. We show that one may eliminate this problem by modifying the Feynman rules of the SM for some vertices containing the Higgs boson; the modifying factors are equal to 1 in the limit m W = m Z  cos  θ W . We give the result for S in a model with arbitrary numbers of scalar SU (2) triplets with weak hypercharges either 0 or 1. [ABSTRACT FROM AUTHOR]

We consider extensions of the standard model (SM) with neutral scalars in multiplets of SU (2) larger than doublets. When those scalars acquire vacuum expectation values, the resulting masses of the gauge bosons W ± and Z 0 are not related by m W = m Z  cos  θ W . In those extensions of the SM the oblique parameters S and U, when computed at the one-loop level, turn out to be either gauge-dependent or divergent. We show that one may eliminate this problem by modifying the Feynman rules of the SM for some vertices containing the Higgs boson; the modifying factors are equal to 1 in the limit m W = m Z  cos  θ W . We give the result for S in a model with arbitrary numbers of scalar SU (2) triplets with weak hypercharges either 0 or 1. [ABSTRACT FROM AUTHOR]

The Forward Physics Facility (FPF) is a proposal to create a cavern with the space and infrastructure to support a suite of far-forward experiments at the Large Hadron Collider during the High Luminosity era. Located along the beam collision axis and shielded from the interaction point by at least 100 m of concrete and rock, the FPF will house experiments that will detect particles outside the acceptance of the existing large LHC experiments and will observe rare and exotic processes in an extremely low-background environment. In this work, we summarize the current status of plans for the FPF, including recent progress in civil engineering in identifying promising sites for the FPF and the experiments currently envisioned to realize the FPF's physics potential. We then review the many Standard Model and new physics topics that will be advanced by the FPF, including searches for long-lived particles, probes of dark matter and dark sectors, high-statistics studies of TeV neutrinos of all three flavors, aspects of perturbative and non-perturbative QCD, and high-energy astroparticle physics. [ABSTRACT FROM AUTHOR]

We study the effect of non-universal Z′ boson on the rare leponic decay modes of B s ∗ mesons, mediated by b → sll quark transition. Rare B decays are sensitive to various new physics operators. As B mesons are composite particles, such decay modes of the excited states are ideal for probing new physics beyond the standard model. We have constrained our model parameters from B s , d − B ¯ s , d mixing data to predict the lepton polarization asymmetry of B s , d ∗ → μ + μ − channel. It is found that this asymmetry deviates from its SM prediction along with the Z′ effect. [ABSTRACT FROM AUTHOR]

Behind succeeding measurements of anomalies in semileptonic decays at LHCb and several collider experiments hinting at the possible violation of lepton flavor universality, we undertake a concise review of theoretical foundations of the tree- and loop-level b-hadron decays, b→clνl and b→sl+l− along with experimental environments. We revisit the world averages for RD(D*), RK(K*), RJ/ψ, and Rηc, for the semileptonic transitions and provide results within the framework of the relativistic independent quark model in addition to the results from model-independent studies. If the ongoing evaluation of the data of LHC Run 2 confirms the measurements of Run 1, then the statistical significance of the effect in each decay channel is likely to reach 5 σ. A confirmation of these measurements would soon turn out to be the first remarkable observation of physics beyond the Standard Model, providing a wider outlook on the understanding of new physics.

Rare decays of hyperons involving di-neutrinos in the final state Λ → n ν ̄ ν , Σ + → p ν ̄ ν , Ξ 0 → Λ ν ̄ ν , Ξ 0 → Σ 0 ν ̄ ν , Ξ − → Σ − ν ̄ ν , Ω − → Ξ − ν ̄ ν in the Standard Model and beyond are studied. It is claimed that the branching ratios (Brs) calculated in this work are larger than the previously calculated values. For the search of NP the nonstandard neutrino interactions (NSI) are explored and constrains on NSI free parameters τ τ u L are found. Stringent bounds on τ τ u L of O (1 0 − 2) are obtained. It is shown that Brs could be closed to BES-III, if the constraints are O (0. 3). We predict that these reactions with the current value of parameter of O (1) will be in sensitivity of BES-III. To check the validity of our approach we also calculate Brs of these reactions by using 331 model and finding them consistent with previously available values of the same model. [ABSTRACT FROM AUTHOR]

The existence of the Higgs boson was postulated more than 50 years ago, without any indication of its mass. The quest that followed, with several generations of particle physics experiments, culminated with the recent discovery of a new particle with a mass of 125 GeV. At least another half-century will be needed to map the properties of this particle with sufficient precision to understand its deepest origin.

We review and discuss recent work exploring the implications of the Higgs field for early universe cosmology, and vice versa. Depending on the model under consideration, the Higgs may be one of a few scalar fields determining the evolution and fate of the Universe, or the Higgs field may be connected to a rich sector of scalar moduli with complicated dynamics. In particular, we look at the potential consequences of the Higgs field for inflation and its predictions, for the (meta)stability of the Standard Model vacuum, and for the existence of dynamical selection mechanisms in the landscape.

The standard model (SM) of particle physics, comprised of the unified electroweak and quantum chromodynamic theories, accurately explains almost all experimental results related to the micro-world, and has made a number of predictions for previously unseen particles, most notably the Higgs scalar boson, that were subsequently discovered. As a result, the SM is currently universally accepted as the theory of the fundamental particles and their interactions. However, in spite of its numerous successes, the SM has a number of apparent shortcomings, including: many free parameters that must be supplied by experimental measurements; no mechanism to produce the dominance of matter over antimatter in the universe; and no explanations for gravity, the dark matter in the universe, neutrino masses, the number of particle generations, etc. Because of these shortcomings, there is considerable incentive to search for evidence for new, non-SM physics phenomena that might provide important clues about what a new, beyond the SM theory (BSM) might look like. Although the center-of-mass energies that BESIII can access are far below the energy frontier, searches for new, BSM physics are an important component of its research program. This report reviews some of the highlights from BESIII's searches for signs of new, BSM physics by: measuring rates for processes that the SM predicts to be forbidden or very rare; searching for non-SM particles such as dark photons; performing precision tests of SM predictions; and looking for violations of the discrete symmetries C and CP in processes for which the SM expectations are immeasurably small. [ABSTRACT FROM AUTHOR]

In the context of precise measurements in some of the CKM elements and angles of the unitarity triangle coupled with latest theoretical improvements of lattice QCD calculations of "hadronic factors," we have explored the implication of these and unitarity on some of the CKM parameters which are ridden with ambiguities. In particular, we have undertaken a thorough scrutiny of the implications of the precise measurements of the angles of the unitarity triangle along with the element | V u s | , on the | V u b | , | V t d | , | V t s | , as well as the CP violating parameter K . Interestingly, we find a unitarity-based analysis while unambiguously favoring | V u b | exclusive-over-inclusive value which is also in agreement with the present data pertaining to K , | V t d | , | V t s | , Δ M d / Δ M s , etc. The present analysis also shows that the presence of NP in K − K ̄ and B d − B d ¯ systems, if any, would be less than a few percent only. [ABSTRACT FROM AUTHOR]

Recently, many discrepancies between the Standard Model (SM) predictions and experimental results have been found in b → c l − v ̄ l quark transitions. Motivated by these discrepancies, we investigated the semileptonic B c → η c τ − v ̄ τ decay in W ′ model. In this paper, we have estimated different decay observables such as branching ratio, lepton flavor universality (LFU) ratio R η c and forward–backward asymmetry in the SM as well as in the W ′ model. In W ′ model, we find significant deviations from the SM for the observables except for the forward–backward asymmetry. This deviation gives us a possible indication of new physics (NP). [ABSTRACT FROM AUTHOR]