Motivated by an anomaly in R(D(⁎))=BR(B¯→D(⁎)τ−ν¯)/BR(B¯→D(⁎)l−ν¯) reported BaBar, Belle and LHCb, we study R(D(⁎)) a general two Higgs doublet model (2HDM). Although it has been suggested that is difficult for the 2HDM to explain current world average R(D(⁎)), would be important clarify how large deviations from standard predictions are possible 2HDM. We investigate corrections taking into account various flavor physics constraints (such as Bc−→τ−ν¯, b→sγ, b→sl+l−, ΔmBd,s, Bs→μ+μ− τ+τ−,...

A bstract Polarization measurements in $$ \overline{B}\to {D}^{\left(\ast \right)}\tau \overline{\nu} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>D</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> <mml:mi>τ</mml:mi> <mml:mi>ν</mml:mi> </mml:math> are useful to check consistency new physics explanations for the R D and {R}_{D^{*}} <mml:msub> <mml:mi>R</mml:mi>...

Measurements of the branching ratios $B\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\tau}\overline{\ensuremath{\nu}}/B\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\ell}\overline{\ensuremath{\nu}}$ and ${B}_{c}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\tau}\overline{\ensuremath{\nu}}/{B}_{c}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\ell}\overline{\ensuremath{\nu}}$ by BABAR, Belle LHCb collaborations consistently point towards an abundance taus compared to channels...

Charge-parity (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi><a:mi>P</a:mi></a:math>) asymmetries in charm decays are extremely suppressed the Standard Model and may well be dominated by new-physics contributions. The LHCb Collaboration reported results of direct <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>C</c:mi><c:mi>P</c:mi></c:math> asymmetry measurements <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...

In this paper, we study the extended Standard Model (SM) with an extra Higgs doublet and right-handed neutrinos. If symmetry to distinguish two doublets is not assigned, flavor changing neutral currents (FCNCs) involving scalars are predicted even at tree level. We investigate constraints on FCNCs one-loop level, especially semileptonic $B$ meson decays, e.g. $B \to D^{(*)} \tau \nu$ K^{(*)} ll$ processes, where SM predictions more than $2 \sigma$ away from experimental results. also...

Recently, it was pointed out that the electron and muon g-2 discrepancies can be explained simultaneously by a flavor-violating axion-like particle (ALP). We show parameter regions favored are already excluded muonium-antimuonium oscillation bound. In contrast, those for consistent with this bound when ALP is heavier than 1.5 GeV. propose to search signature of same-sign same-flavor lepton pairs forward-backward asymmetry test model at Belle II experiment.

Abstract We investigate the current LHC bounds on New Physics (NP) that contributes to $${\bar{B}} \rightarrow {D^{(*)}}l{\bar{\nu }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mover> <mml:mi>B</mml:mi> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>D</mml:mi> <mml:mo>(</mml:mo> <mml:mrow /> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:msup> <mml:mi>l</mml:mi> <mml:mi>ν</mml:mi> </mml:math> for $$l = (e,\mu ,\tau )$$...

The two-Higgs-doublet model with a $U(1{)}_{H}$ gauge symmetry (N2HDM-$U(1)$) has several advantages compared to the ``standard'' ${Z}_{2}$ version (N2HDM-${Z}_{2}$): It is purely based on symmetries, involves only spontaneous breaking, and more predictive because it contains one parameter less in Higgs potential, which further ensures $CP$ conservation, i.e., avoiding stringent bounds from electric dipole moments. After pointing out that second, so far unknown of N2HDM-$U(1)$ exists, we...

Abstract The prospects are presented for precise measurements of the branching ratios purely leptonic $$B_c^+ \rightarrow \tau ^+ \nu _\tau $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>c</mml:mi> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>τ</mml:mi> </mml:msup> <mml:msub> <mml:mi>ν</mml:mi> </mml:msub> </mml:mrow> </mml:math> and $$B^+ decays at Future Circular Collider (FCC). This work is...

Recently, several new experimental results of the test lepton flavor universality (LFU) in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>B</a:mi><a:mo stretchy="false">→</a:mo><a:msup><a:mi>D</a:mi><a:mrow><a:mo stretchy="false">(</a:mo><a:mo>*</a:mo><a:mo stretchy="false">)</a:mo></a:mrow></a:msup></a:math> semileptonic decays were announced: first result <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"...

A bstract The discrepancy between the measured value and Standard Model pre- diction for muon anomalous magnetic moment is one of important issues in particle physics. In this paper, we consider a two Higgs doublet model (2HDM) where extra couples to tau lepton flavor violating (LFV) way one-loop correction involving scalars largely contributes moment. couplings should be sizable explain discrepancy, so that bosons would dominantly decay into μτ LFV modes, which makes testable at LHC through...

Motivated by the notorious anomaly in lepton flavor universality ratios $R_{D^{(*)}}$, we study sensitivity of Large Hadron Collider (LHC) to a low-mass charged Higgs boson $H^-$ lighter than $400\,$GeV generic two doublet model. A combination current constraints from $B_c\to\tau \nu$ decay, $B_{s}$ meson mixing data, tau sleptons and di-jet searches at LHC allows explain $R_{D^{(*)}}$ $1\,\sigma$ level Higgs. In this context, estimate reach an search for resonant production, where final...

Recently, the CMS collaboration has reported a di-tau excess with local significance of 2.6-3.1$\sigma$ where invariant mass is $m_{\tau\tau}=$95-100 GeV. This can be interpreted as light scalar boson that couples to third generation fermions, particularly top and $\tau$. Based on simplest model account for excess, we evaluate experimental sensitivities additional resonance, using results by ATLAS collaboration. We see search top-quark associated production SM Higgs decays into...

A bstract Motivated by the $$ b\to c\tau \overline{v} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>b</mml:mi> <mml:mo>→</mml:mo> <mml:mi>cτ</mml:mi> <mml:mover> <mml:mi>v</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> anomalies, we study non-resonant searches for new physics at large hadron collider (LHC) considering final states with an energetic and hadronically decaying τ lepton, a b -jet missing transverse momentum \left( pp\to...

We consider a general two Higgs doublet model which can simultaneously solve discrepancies in neutral B meson decay ($b\to s\ell \overline \ell$ distribution) and charged c\tau\overline\nu$) with Higgs. The contains additional scalars at the same mass scale predicts distinctive signals LHC. Based on recent same-sign top search by ATLAS collaboration, we found constraint scalar spectrum. To probe remaining window, propose novel $cg\to t\tau\overline\tau$ process

Lepton flavor universality violations in semileptonic $b \to c$ transitions have garnered attention over a decade. For $R_{H_c}={\rm{BR}}(H_b\to H_c \tau\bar\nu_\tau)/{\rm{BR}}(H_b\to \ell\bar\nu_\ell)$ with $\ell$ being $e,\, \mu$, sum rule among $R_{D}$ $R_{D^*}$ and $R_{\Lambda_c}$ was proposed to check consistency the experimental results independently of new physics models. We revisit this relation from perspective heavy quark symmetry. derive holding exactly limit clarify how...

There are discrepancies between the experimental results and Standard Model predictions, in lepton flavor universality of semileptonic $B$ decays: $B \to D^{(*)} \ell \nu$. As new physics interpretations, charged vector scalar fields, that dominantly couple to second third generations, have been widely discussed. In this paper, we study signals particles at LHC, test interpretations via direct search for resonances. particular, see $\tau \nu$ resonance LHC has already covered most parameter...

A bstract The discrepancy between the measured value and Standard Model prediction of muon anomalous magnetic moment is one most important issues in particle physics. It known that introducing a mediator boson X with μτ lepton flavor violating (LFV) couplings good solution to explain discrepancy, due τ mass enhancement one-loop correction. In this paper, we study signal model, i.e. same-sign leptons, Belle II experiment, assuming flavor-diagonal are suppressed. We show experiment highly...

Thanks to the recent careful revisit of theoretical prediction $B_c$ meson lifetime, conservative upper bound on branching ratio (BR) $\tau \nu$ mode is found be $\simeq 63\%$ due large charm quark mass uncertainty. Although it well known that a charged Higgs ($H^-$) interpretation $R_{D^{(*)}}$ anomaly excluded by previously proposed bounds, BR$(B_c\to\tau\nu)\le 30\%$ and $\le10\%$, $H^-$ can still explain within $1\sigma$ if we adopt 63$\%$ one. The scalar contribution also favored...

We examine the sensitivity of Large Hadron Collider (LHC) to light lepton portal dark matter with its mass below 10$\,$GeV. The model features an extra doublet scalar field and singlet Dirac matter, which have Yukawa interactions left-handed leptons. To correctly produce abundance via thermal freeze-out, a large splitting among scalars is required, thus providing neutral ${\cal O}(10)$GeV heavy charged at electroweak scale. In this paper, we focus on pair-production subsequent model-specific...

Form factors are a crucial theory input in order to extract $|{V}_{cb}|$ from $B\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\ell}\ensuremath{\nu}$ decays, calculate the Standard Model prediction for $\mathcal{R}({D}^{(*)})$ and assess impact of new physics. In this context, dispersive matrix approach, first-principle calculation form factors, using no experimental data but rather only lattice QCD results as input, was recently applied...

We investigate the di-Higgs production at Large Hadron Collider in two-Higgs doublet model (2HDM). In particular, we study of an extra neutral Higgs boson $\ensuremath{\phi}$ association with Standard Model (SM) $h$ alignment limit. analyze two scenarios where additional is a $CP$-even or -odd state large top-Yukawa interaction. The leading contribution this comes from top-quark loop-induced gluon-fusion channel $gg\ensuremath{\rightarrow}h\ensuremath{\phi}$. measurement $h\ensuremath{\phi}$...

Recently, the standard model predictions for $B$-meson hadronic decays, $\bar{B}^0 \to D^{(\ast)+}K^-$ and $\bar{B}^0_s D^{(\ast)+}_s \pi^-$, have been updated based on QCD factorization approach. This improvement sheds light a novel puzzle in decays: there are mild but universal tensions between data predicted branching ratios. Assuming higher-order corrections not huge enough to solve tension, we examine several new physics interpretations of this puzzle. We find that tension can be...

In this paper, we show an explicit way to realize a TeV-scale vector leptoquark from the Pati-Salam (PS) unification with extra vectorlike families. The mass is constrained be heavier than PeV-scale by measurement of flavor violating kaon decay, $K_L \to \mu e$, in conventional models. This strong constraint can avoided introducing families consistently quark and lepton masses CKM PMNS matrices. other processes are also suppressed. model, sufficiently light explain recent $b\to s\mu\mu$...

A bstract Motivated by the reported discrepancies between experimental data and Standard Model predictions for branching ratios of color-allowed decays $$ \overline{B} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> 0 → D (*)+ K − {\overline{B}}_s^0 <mml:msubsup> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> {D}_s^{\left(\ast \right)+}{\pi}^{-} <mml:mi>D</mml:mi> <mml:mrow> <mml:mfenced>...