arXiv subjects

Jong-Phil Lee

Publications and source records attributed to Jong-Phil Lee.

At least 19 recordsLinked to original sources

arXiv2026

$B$ anomalies and the tauphilic leptoquark model

We suggest three scalar leptoquarks, $S_1$, ${\tilde R}_2$, and $S_3$ which couple exclusively to the 3rd generation of leptons to explain the $B$ anomalies. The scalar singlet $S_1$ can explain $R(D^{(*)})$, while the doublet ${\tilde R}_2$ is needed to fit the branching ratio ${\rm Br}(B\to K^{(*)}ν{\barν})$ via the right-handed Wilson coefficients $C_R^ν$. A strong constraint from $Δm_{B_s}$ requires triplet $S_3$ where the mixing term between $S_1$ and $S_3$ is important. Our analysis suggests subdominant $C_{V_L}<0$ and dominant $C_{S_L} >0$ and lepton-flavor universality violating $C_9^{\rm LQ} \approx +1$. The masses are expected to be $M_{S_1}\sim M_{{\tilde R}_2} < M_{S_3} \lesssim 3$ TeV, which can be probed in future colliders.

hep-ph↗

arXiv2026

$Λ_b\toΛ^{(*)}ν{\barν}$ and $b\to s$ $B$ decays

The baryonic $b\to s$ transition $Λ_b\toΛ^{(*)}ν{\barν}$ is analyzed. We combine the mesonic counterpart $B^+\to K^+ν{\barν}$ and $B^0\to K^{*0}ν{\barν}$ as well as other observables involving $B$ mesons like $R(K^{(*)})$, ${\rm Br}(B_s\toμ^+μ^-)$, ${\rm Br}(B^+\to K^+μ^+μ^-)$, and $P_5'(B^+\to K^{*+}μ^+μ^-)$. Using the constraints from mesonic sector, we present predictions for the currently unobserved baryonic decay modes, which is very complementary to mesonic modes for probing new physics. We find that the new physics scale $M_{\rm NP}$ to be $2.04~{\rm TeV}\le M_{\rm NP} \le 11.76~{\rm TeV}$ (at $1σ$) for ordinary heavy new mediators. Our predictions for the branching ratios ${\rm Br}(Λ_b\toΛ^{(*)}ν{\barν})$ are $2.07 (1.07)$ times the standard model estimations, which could be verified at future colliders. We also find a sum rule for ${\rm Br}(Λ_b\toΛν{\barν})$ and ${\rm Br}(B\to K^{(*)}ν{\barν})$ that is very similar to that for $b\to c$ semi-leptonic decays.

hep-ph↗

arXiv2025

New physics effects in $R(K^{(*)})$, $B_s\toμ^+μ^-$, and $B^+\to K^+ν{\barν}$

We analyze possible new physics (NP) effects on $b\to s$ transition processes, $R(K^{(*)})$, $B_s\toμ^+μ^-$, and $B^+\to K^+ν{\barν}$ decays. Though recent data for $R(K^{(*)})$ and ${\rm Br}(B_s\toμ^+μ^-)$ are compatible with the standard model (SM), there are still rooms for NP beyond the SM. Especially ${\rm Br}(B^+\to K^+ν{\barν})$ is measured to exceed the theoretical predictions. We parameterize the NP effects in a generic way with explicit NP scale $M_{\rm NP}$ and some possible powers of it. For reasonable ranges of NP fermionic couplings we find a window of $3.17~{\rm TeV} \le M_{\rm NP}\le 14.9~{\rm TeV}$ for new particles. When including ${\rm Br}(B^+\to K^+μ^+μ^-)$ and the angular observable $P_5'(B^+\to K^{*+}μ^+μ^-)$ we have a wider range of the window. Implications of our analysis about specific NP models are discussed.

hep-ph↗

arXiv2025

New physics effects on $B\to D^{(*)}τν$ decays

We investigate new physics effects on $B\to D^{(*)}τν$ decays in a general and model-independent way. The $χ^2$ fits for fractions of the branching ratios $R(D^{(*)})$ and other polarization parameters are implemented. We parameterize the relevant Wilson coefficients with a new physics scale and its power together with combined fermionic couplings. Constraints from $B_c\toτν$ are imposed such that its branching ratio is less than 30%. For a moderate range of our parameters we find that the new physics scale goes up to $\lesssim 27$ TeV for ordinary new particle contributions. It turns out that the polarization asymmetry of $τ$ for $B\to D$ transition can be negative only for a few combinations of the new physics operators. We also discuss related processes $B_c\to J/Ψτν$ and $Λ_b\toΛ_cτν$ decays.

hep-ph↗

arXiv2023

Tree-level new physics in $R(K^{(*)})$

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 $B_s\toμ^+μ^-$ 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 $\sim 5~{\rm TeV}$. 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.

hep-ph↗

arXiv2023

$R(K^{(*)})$ with vector unparticles

We analyze the unparticle effects on the lepton flavor universality violating ratios in $b\to s$ transition, $R(K^{(*)})$. We concentrate on the vector unparticles which contribute to the relevant Wilson coefficients $C_{9,10}$. New effects appear in the form of some powers of the momentum transfer squared, which is a different feature from other new physics models like leptoquarks or $Z'$. Constraints from $B_s$-${\bar B}_s$ mixing, $B_s\toμ^+μ^-$, and the electron/muon anomalous magnetic moments are considered. It is found that the vector unparticles successfully explain $R(K^{(*)})$ with moderate values of model parameters.

hep-ph↗

arXiv2021

Model-independent analysis on $R(K^{(*)})$

We analyze the lepton-universality violating $B\to K^{(*)}\ell^+\ell^-$ puzzle $R(K^{(*)})$ in a model-independent way. The branching ratio ${\rm Br}(B_s\toμ^+μ^-)$ is also considered as a main constraint. We show how the branching ratio restricts the allowed region of the parameter space, and investigate new physics effects on the electronic as well as muonic sector in $R(K^{(*)})$. Within a reasonable range of parameters we find that the new physics scale goes up to $\sim 5$ TeV, and the new physics effects on the Wilson coefficient is $-1\lesssim C_{9NP}^μ\lesssim 0$.

hep-ph↗

arXiv2020

$B$ anomalies with unparticles

We analyze the $B$ anomalies associated with the $B\to D^{(*)}τν$ decays in the unparticle model. The fraction of the branching ratios $R(D^{(*)})$ and other parameters related to the polarization are fitted to the experimental data by minimizing $χ^2$. The best-fit values are $R(D)_{\rm best}=0.371$ and $R(D^*)_{\rm best}=0.266$ which are still larger than the standard model predictions. We find that our results safely render the branching ratio ${\rm Br}(B_c\toτν)$ below $10\%$.

hep-ph↗

arXiv2019

$B$ anomalies in the nonminimal universal extra dimension model

We investigate the $B$ anomalies in the framework of the nonminimal universal extra dimension models. Newly measured polarization parameters in $B\to D^{(*)}τν$, $P_τ(D^{(*)})$ and $F_L(D^*)$ as well as the ratios $R(D^{(*)})$ are considered altogether. The Kaluza-Klein modes of the $W$-boson and charged scalar contributes as the new physics effects. We find that the model parameters fit the global data very well with the minimum $χ^2/{\rm d.o.f.}$ near unity, rendering $B_c\toτν$ branching ratios to be a few percents. The best-fit values of $R(D)$ and $R(D^*)$ are still far from ($\gtrsim 2σ$) the standard model predictions.

hep-ph↗

arXiv2018

Unparticle effects on $B\to D^{(*)}τν$

We examine the possible unparticle effects on $R(D^{(*)})$ associated with $B\to D^{(*)}τν$ decays by minimum-$χ^2$ fitting. Recent measurements from Belle and LHCb are included in this analysis. While it is true that the new experimental results of $R(D^{(*)})$ get closer to the standard model predictions, there are still rooms for new physics and unparticles are also one possibility. Our best-fit values are $R(D)=0.456$ and $R(D^*)=0.270$, which are still far from the standard model values by more than ($R(D)$) or almost ($R(D^*)$) $2σ$. We also find that the unparticle effects are quite safe to render the branching ratio ${\rm Br}(B_c\toτν)$ less than 10\%.

hep-ph↗

arXiv2017

$B\to D^{(*)}τν_τ$ in the 2HDM with an anomalous $τ$ coupling

The puzzle of $R(D^{(*)})$ associated with $B\to D^{(*)}τν$ decay is addressed in the two-HIggs-doublet model. An anomalous coupling of $τ$ to the charged Higgs is introduced to fit the data from BaBar, Belle, and LHCb. It is shown that all of the four types of the model yield similar values of the minimum $χ^2$. Also shown is that the newly normalized $R(D^{(*)})$ with the branching ratio of $B\toτν$ decay exhibits much smaller minimum $χ^2$.

hep-ph↗

arXiv2017

$B_s \to μτ$ and $h \to μτ$ decays in the general two Higgs doublet model

Inspired by the recent measurement of the $h \to μτ$ decays by the CMS collaboration at the LHC, we study the lepton flavour-violating (LFV) $B_s \to μτ$ decays in the general two Higgs doublet model. Those LFV interactions could accommodate the present deviation of the muon anomalous magnetic moment and also predict the LFV $τ$ decay processes such as $τ\to μμμ$ and $τ\to μγ$. We find that the $B_s \to μτ$ decay rates should be sizable with above experimental conditions in the framework of our model. These processes are expected to be observed at the colliders such as LHCb and Belle-II in the future.

hep-ph↗

arXiv2016

Higgs potential and hidden light Higgs scenario in two Higgs doublet models

In two Higgs doublet models (2HDM), there exists an interesting possibility, the hidden light Higgs scenario, that the discovered SM-like Higgs boson is the heavier \textit{CP}-even Higgs boson $H^0$ and the lighter \textit{CP}-even $h^0$ has not been observed yet in any experiment. We study the current status of this scenario in Types I, II, X, and Y, through the scans of the 2HDM parameters with all relevant theoretical and experimental constraints. We employ not only the most up-to-date Higgs signal strength measurements with the feed-down effects, but also all the available LHC exclusion limits from heavy Higgs searches. Adjusting the heavier $H^0$ to the 125 GeV state while hiding the lighter $h^0$ from the LEP Higgs search prohibits the extreme decoupling limit: there exist upper bounds on the masses of the pseudoscalar $A^0$ and the charged Higgs $H^\pm$ below about 600 GeV. In addition, the $Z_2$ symmetry is shown to be a good approximate symmetry since the soft $Z_2$ symmetry breaking parameter $m_{12}^2$ should be less than about (45 GeV)$^2$. Most interestingly, a few parameters in the Higgs potential and the related Higgs triple and quartic couplings are shown to be meaningfully constrained by the current data. The double Higgs-strahlung process at an $e^+ e^-$ collider is also studied.

hep-ph↗

arXiv2014

Two Higgs doublet models for the LHC Higgs boson data at $\sqrt{s}=$ 7 and 8 TeV

Updated LHC data on the new 126 GeV boson during the 7 and 8 TeV runnings strengthen the standard model Higgs boson interpretation further. Through the global $χ^2$ analysis, we investigate whether the new particle could be one of the scalar particles in two Higgs doublet models. Four types (Type I, II, X and Y) are comprehensively studied. Taking the recent analysis on the spin-parity of the new boson, we consider two scenarios: the new boson is either the light CP-even one ($h^0$) or the heavy CP-even one ($H^0$). It is found that both scenarios are consistent with the new data, not only in the parameter regions near the decoupling limit but also in other regions far from the decoupling limit. In addition, the current data are compatible with the possibility that the light Higgs boson $h^0$ is hidden in the mass window of 90-100 GeV. The diphoton or $ττ$ channel can provide a probe of this possibility by the enhanced signal rates.

hep-ph↗

arXiv2014

New Physics in $B_{d,s}$-$\Bbar_{d,s}$ mixings and $B_{d,s}\toμ^+μ^-$ decays

A new way of probing new physics in the $B$ meson system is provided. We define double ratios for the observables of $B_{d,s}$-$\Bbar_{d,s}$ mixings and $B_{d,s}\toμ^+μ^-$ decays, and find simple relations between the observables. By using the relations we predict the yet-to-be measured branching ratio of $B_d\toμ^+μ^-$ to be $(0.809\sim1.03)\times 10^{-10}$, up to the new physics models.

hep-ph↗

arXiv2013

Constraints on Unparticles from $B_s\toμ^+μ^-$

Unparticle contributions to the recently measured decay mode $B_s\toμ^+μ^-$ are analyzed. We consider only the scalar unparticles because vector unparticles are expected to provide negligible contributions. Assuming that the relevant coupling constants are real, we present allowed regions of coupling constants and the scaling dimension of the scalar unparticle. While the measured value of the branching ratio is very close to the standard model predictions, one cannot exclude the possible contributions from unparticles.

hep-ph↗

arXiv2012

Comprehensive study of two Higgs doublet model in light of the new boson with mass around 125 GeV

The recent discovery of a new boson of mass roughly 125 GeV has been reported by the ATLAS and CMS collaborations. Although its signals in various decay modes resemble those of the standard model (SM) Higgs boson, observed are the combinations of entangled information about the production, decay rates and total decay width of the new boson. In addition, some decay channels show non-negligible deviation from the SM expectation, such as the $2σ$ excess in the diphoton channel. In the four types (I, II, X and Y) of two Higgs doublet models, we perform the global $χ^2$ fit in three scenarios: (i) the new boson is the light CP-even Higgs boson $h^0$; (ii) it is the heavy CP-even Higgs boson $H^0$; (iii) the signals are from degenerate $h^0$ and the pseudoscalar $A^0$. Considering other phenomenological constraints such as flavor physics, electroweak precision data, and the LEP search for the Higgs boson, we find that the the first scenarios in Type II and Type Y models actually provide better or similarly good fit to the data than the SM. All the other models are excluded at 95% C.L..

hep-ph↗

arXiv2012

Quantization of $D$-dimensional noncommutative black holes

Noncommutative black holes in higher dimensions are investigated in the context of holographic principle. Quantization rules for the discrete mass spectrum are derived and compared with the continuous spectrum in the literature. Because of the noncommutative nature of background geometry the minimum mass to form a noncommutative black hole is very large (it becomes larger for discrete spectra), so the current LHC search results for mini black holes cannot exclude the possibility of quantum gravity in higher dimensions.

gr-qc↗