arXiv subjects

Jong-Phil Lee

Publications and source records attributed to Jong-Phil Lee.

At least 55 records · Page 3Linked to original sources

arXiv2004

Soft Wilson lines in soft-collinear effective theory

The effects of the soft gluon emission in hard scattering processes at the phase boundary are resummed in the soft-collinear effective theory (SCET). In SCET, the soft gluon emission is decoupled from the energetic collinear part, and is obtained by the vacuum expectation value of the soft Wilson-line operator. The form of the soft Wilson lines is universal in deep inelastic scattering, in the Drell-Yan process, in the jet production from e+e- collisions, and in the gamma* gamma* -> pi0 process, but its analytic structure is slightly different in each process. The anomalous dimensions of the soft Wilson-line operators for these processes are computed along the light-like path at leading order in SCET and to first order in alpha_s, and the renormalization group behavior of the soft Wilson lines is discussed.

hep-ph↗

arXiv2004

Implications of the first observation of $B\to K_1γ$

Implications of the recent new measurements of $B\to K_1γ$ by Belle are examined. It is shown that the new branching ratio $\calB(B\to K_1(1270)γ)$ requires very large form factor compared to the theoretically predicted one. This is an opposite case to $B\to K^*γ$ where theory expected larger branching ratio. Possible origins of the discrepancy are discussed.

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arXiv2004

Radiative B decays to the axial $K$ mesons at next-to-leading order

We calculate the branching ratios of $B\to K_1γ$ at next-to-leading order (NLO) of $α_s$ where $K_1$ is the orbitally excited axial vector meson. The NLO decay amplitude is divided into the vertex correction and the hard spectator interaction part. The one is proportional to the weak form factor of $B\to K_1$ transition while the other is a convolution between light-cone distribution amplitudes and hard scattering kernel. Using the light-cone sum rule results for the form factor, we have $\calB(B^0\to K_1^0(1270)γ)=(0.828\pm0.335)\times 10^{-5}$ and $\calB(B^0\to K_1^0(1400)γ)=(0.393\pm0.151)\times 10^{-5}$.

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arXiv2003

Photon polarization in $B\to K_{\rm res}γ$

In this talk, I introduce recently proposed method for measuring the photon polarization in $B\to K_{\rm res}γ$. It is also shown that anomalous right-handed top couplings can severely affect the photon polarization without spoiling the well measured branching ratio of $B\to X_sγ$. Estimated number of $B$ mesons needed for measuring the photon polarization is already within the reach of current $B$ factories.

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arXiv2003

$B\Bbar$ mixing with the bulk fields in the Randall-Sundrum model

We calculate the $B\Bbar$ mixing in the Randall-Sundrum bulk model. In this model, all the Standard Model fields except the Higgs can reside in the bulk. Two suggestive models of "mixed" and "relaxed" scenarios are considered. We find that the enhancement of the loop function is 0.51% for the "relaxed" and 1.07% for the "mixed" scenario when the first 4th KK modes are included, for a bulk fermion mass parameter $ν=-0.3$.

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arXiv2003

Photon polarization with anomalous right-handed top couplings in $B\to K_{res}γ$

The effect of anomalous right-handed top couplings on the photon polarization in $B\to K_{\rm res}γ$ is investigated. It is recently reported that the photon polarization can be measured through the up-down asymmetry of the photon direction relative to the subsequent $K_{\rm res}$ decay plane. We find that the anomalous couplings can severely affect the photon polarization without spoiling the well measured branching ratio of $B\to X_sγ$. Different features from other scenarios are also discussed.

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arXiv2003

CP violation in $B \to ϕK$ decay and anomalous right-handed top quark couplings

We explore the CP violation in $B \to ϕK$ decay processes in the presence of the anomalous right-handed $\bar{t}sW$ and $\bar{t}bW$ couplings. The complex anomalous top coupling can be a source of the new CP violation and lead to a deviation of the observed weak phase in $B \to ϕK$ decays, which takes account for the present disagreement of the observed $\sin 2 β$ between $B \to J/ψK$ and $B \to ϕK$ decays. The direct CP violation is also predicted.

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arXiv2003

Nonleptonic B decays into a charmed tensor meson

In the framework of the factorization and the heavy quark effective theory, $B\to D_2^*π$ modes are analyzed. We adopt the result from the QCD sum rule calculation for the hadronic matrix elements at leading order of $Λ_{\rm QCD}/m_Q$ and $α_s$. The QCD sum rule results are well compatible with the current data, with the prediction on the branching ratios $\calB(\Bbar^0\to D_2^{*+}π^-)=8.94\times 10^{-4}$ and $\calB(B^-\to D_2^{*0}π^-)=9.53\times 10^{-4}$ for $N_C^{\rm eff}=2$. We give constraints on the interception $τ(1)$ and the slope parameter $ρ^2$ of the leading Isgur-Wise function from the experimental bounds. It is argued that the observation of nonzero $\calB(\Bbar^0\to D_2^{*0}π^0)$ directly measures the nonfactorizable effets.

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arXiv2003

Heavy-to-light form factors of B decays at large recoil

The form factors of $B\toπ(ρ)$ decays are analyzed using the light-cone sum rules in the framework of the soft-collinear effective theory (SCET). We establish the sum rules for the leading and the next-to-leading order (NLO) nonperturbative functions of the SCET. Explicit calculation shows that (leading)+(NLO) $\sim 1/E^2+1/E^3$, where $E$ is the large recoiling energy. The results are compatible with the literatures. Also the validity of this hybrid formalism is discussed.

hep-ph↗

arXiv2002

Nonleptonic two-body charmless B decays involving a tensor meson in ISGW2 model

Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic uncertainties and ambiguities of the form factors which appear in the literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to evaluate the relevant hadronic matrix elements. We calculate the branching ratios and CP asymmetries for various $B\to P(V)T$ decay processes. With the ISGW2 model, the branching ratios are enhanced by about an order of magnitude compared to the previous estimates. We show that the ratios $\calB(B\to VT)/\calB(B\to PT)$ for some strangeness-changing processes are very sensitive to the CKM angle $γ$ ($ϕ_3$).

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arXiv2002

Hadronic decays of B involving a tensor meson through a $b \to c$ transition

We re-analyze hadronic decays of B mesons to a pseudoscalar (P) and a tensor meson (T), or a vector meson (V) and a tensor meson, through a $b \to c$ transition. We discuss possible large uncertainties to branching ratios (BR's) of the relevant modes, mainly arising from uncertainties to the hadronic form factors for the $B \to T$ transition. The BR's and CP asymmetries for $B \to PT$ and VT decays are then calculated by using the form factors given in the ISGW2 model (the improved version of the original Isgur-Scora-Grinstein-Wise (ISGW) model). We find that the estimated BR's of many modes are increased by an order of magnitude, compared to the previous results calculated within the ISGW model.

hep-ph↗

arXiv2002

Subleading Isgur-Wise Function of $Λ_b\toΛ_{c1}$ using QCD sum rules

Subleading Isgur-Wise form factor $τ(v\cdot v')$ at ${\cal O}(1/m_Q)$ for $Λ_b\toΛ_{c1}^{1/2,3/2}$ weak transition is calculated by using the QCD sum rules in the framework of the heavy quark effective theory (HQET), where $Λ^{1/2}_{c1}$ and $Λ^{3/2}_{c1}$ are the orbitally excited charmed baryon doublet with $J^P=(1^-/2,3^-/2)$. We consider the subleading contributions from the weak current matching in the HQET. The interpolating currents with transverse covariant derivative are adopted for $Λ^{1/2}_{c1}$ and $Λ^{3/2}_{c1}$ in the analysis. The slope parameter $ρ^2$ in linear approximation of $τ$ is obtained to be $ρ^2=2.76$ and the interception to be $τ(1)=-1.27$ GeV.

hep-ph↗

arXiv2001

CP violating transverse lepton polarizaion in $B\to D^{(*)}\ell\barν$ including tensor interactions

We give a model-independent analysis of CP violating lepton polarization in the exclusive semileptonic B decay of $B\to D^{(*)}\ell\barν$ including dimension six four-fermion tensor interactions at the heavy quark limit. It is shown that the tensor interactions should not be neglected if the associated couplings are comparable to others. The effect of tensor interactions on the transverse lepton polarization appears more dramatically in $B\to D$ than in $B\to D^*$. In the leptoquark model, the average transverse lepton polarization is estimated to be $|\bar{P^\perp_D}|\simeq 0.26$ and $|\bar{P^\perp_{D^*}}|\simeq 0.076$ with commonly used model parameters.

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arXiv2001

Non-factorizable effects on $\Bbar^0\to D^{(*)0}π^0$

Non-factorizable effects on the color-suppressed $B\to D^{(*)}π$ decay modes are analyzed. Recent observations of $\Bbar^0\to D^{(*)0}π^0$ by Belle and CLEO strongly suggest that there exists a non-zero strong phase difference between color-allowed and color-suppressed decay modes, and the factorization parameter $a_2$ associated with the color-suppressed decay mode is process dependent. In the heavy quark limit where $b$ and $c$ are heavy, the process dependence of $a_2(Dπ,D^*π)$ is due to the different configuration of the heavy quark spin relative to the light degrees of freedom. From the experimental data, the heavy quark spin symmetry breaking contributions to the non-fatorizable effects are estimated to be $23-28%$.

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arXiv2000

Leading Isgur-Wise form factor of $Λ_b\toΛ_{c1}$ transition using QCD sum rules

The leading Isgur-Wise form factor $ξ(y)$ parametrizing the semileptonic transitions $Λ_b\toΛ^{1/2}_{c1}\ell\barν$ and $Λ_b\toΛ^{3/2}_{c1}\ell\barν$ is calculated by using the QCD sum rules in the framework of heavy quark effective theory, where $Λ^{1/2}_{c1}$ and $Λ^{3/2}_{c1}$ is the orbitally excited charmed baryon doublet with $J^P=(1^-/2,3^-/2)$. The interpolating currents with transverse covariant derivative are adopted for $Λ^{1/2}_{c1}$ and $Λ^{3/2}_{c1}$ in the analysis. The slope parameter $ρ^2$ in linear approximation of the Isgur-Wise function is obtained to be $ρ^2=2.01$, and the interception to be $ξ(1)=0.29$. The decay branching ratios are estimated.

hep-ph↗

arXiv2000

Excited Heavy Baryon Masses from the 1/N_c Expansion of HQET

The mass spectra of the L=1 orbitally excited heavy baryons with light quarks in both the spin-flavor symmetric and the mixed representations are studied by the $1/N_c$ expansion method in the framework of the heavy quark effective theory. The mixing effect between the baryons in the two representations is also considered. The general pattern of the spectrum is predicted which will be verified by the experiments in the near future.

hep-ph↗

arXiv2000

$1/m_Q$ and $1/N_c$ Expansions for Excited Heavy Baryons with Light Quarks in the Spin-Flavor Symmetric Representation

The mass spectrum of the L=1 orbitally excited heavy baryons with light quarks in the spin-flavor symmetric representation is studied by the $1/N_c$ expansion method in the framework of the heavy quark effective theory. The mixing effect from the baryons in the mixed representation is considered. The general pattern of the spectrum is predicted which will be verified by the experiments in the near future. The $1/m_Q$ and SU(3) corrections are also considered. Mass relations for the baryons $Λ_{c1}^{(*)}$, $Σ_{c1}^{(*)}$, $Ξ_{c1}^{(')(*)}$, and $Ω_{c1}^{(*)}$ are derived.

hep-ph↗

arXiv2000

QCD sum rule analysis of excited $Λ_c$ mass parameter

The mass parameter of orbitally excited $Λ_c$ baryons is calculated by using QCD sum rule in the framework of heavy quark effective theory. Two kinds of interpolating current for the excited heavy baryons are introduced. It is obtained that $\barΛ=1.08^{+0.095}_{-0.104}$ GeV for the non-derivative current and $\barΛ=1.06^{+0.090}_{-0.107}$ GeV for the current with derivative. These results are consistent with experimental data.

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