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Sep 22, 2013
09/13

by
Hai-Yang Cheng

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Cabibbo-allowed two-body hadronic weak decays of bottom baryons are analyzed. Contrary to the charmed baryon sector, many channels of bottom baryon decays proceed only through the external or internal W-emission diagrams. Moreover, W-exchange is likely to be suppressed in the bottom baryon sector. Consequently, the factorization approach suffices to describe most of the Cabibbo-allowed bottom baryon decays. We use the nonrelativistic quark model to evaluate heavy-to-heavy and heavy-to-light...

Source: http://arxiv.org/abs/hep-ph/9612223v2

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Sep 22, 2013
09/13

by
Hai-Yang Cheng

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Theoretical uncertainties with the time-dependent CP asymmetries $\Delta S$ and $A_{\rm CP}$ in $B^0\to K^+K^-K_S$, $K_SK_SK_S$ and $K_S\pi^0\pi^0$ decays are discussed. In order to have a reliable estimate of CP asymmetries, it is very crucial to understand the underlying mechanism for the nonresonant background which dominates the KKK modes.

Source: http://arxiv.org/abs/hep-ph/0702252v1

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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Nonfactorizable contributions to exclusive two-body nonleptonic weak decays of heavy mesons arising from color octet currents, characterized by the parameter $r_2$, are extracted from the data. It is found that $r_2$ is equal to $\sim -0.67\,$, $-(0.9\sim 1.1),~-(1.2\sim 1.3)$, $\sim 0.36$ respectively for $D\to \bar{K}\pi,~\bar{K}^*\pi,~\bar{K}^*\rho,~\bar{B}\to D\pi$ decays. As expected, soft-gluon effects become stronger when the decay particles are less energetic, allowing more time for...

Source: http://arxiv.org/abs/hep-ph/9406262v1

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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The proton spin puzzle inspired by the EMC experiment and its present status are closely examined. Recent experimental progress is reviewed. Various factorization schemes due to the ambiguity arising from the axial anomaly are discussed. Some misconceptions in the literature about the $\MS$ factorization scheme are clarified. It is stressed that the polarized nucleon structure function $g_1(x)$ is independent of the factorization scheme chosen in defining the quark spin density. Consequently,...

Source: http://arxiv.org/abs/hep-ph/0002157v2

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Sep 21, 2013
09/13

by
Hai-Yang Cheng

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The status of exclusive two-body and three-body baryonic B decays is reviewed. The threshold peaking effect in baryon pair invariant mass is stressed and explained. Weak radiative baryonic B decays mediated by the electromagnetic penguin process are discussed.

Source: http://arxiv.org/abs/hep-ph/0311035v1

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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Recent progress in exclusive charmless hadronic decays of the B meson is discussed.

Source: http://arxiv.org/abs/hep-ph/9712244v1

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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Since the x dependence of the axial-anomaly effect in inclusive polarized deep inelastic scattering is fixed, the transformation from the $\bar{MS}$ scheme to different factorization schemes are not arbitrary. If the quark spin distribution is demanded to be anomaly-free so that it does not evolve with $Q^2$ and hard gluons contribute to the first moment of $g_1(x)$, then all the moments of coefficient and splitting functions are fixed by perturbative QCD for a given $\gamma_5$ prescription,...

Source: http://arxiv.org/abs/hep-ph/9712473v3

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Sep 17, 2013
09/13

by
Hai-Yang Cheng

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Using two simple and robust inputs to constrain the mixing matrix of the isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$, we have shown that in the SU(3) symmetry limit, $f_0(1500)$ becomes a pure SU(3) octet and is degenerate with $a_0(1450)$, while $f_0(1370)$ is mainly an SU(3) singlet with a slight mixing with the scalar glueball which is the primary component of $f_0(1710)$. These features remain essentially unchanged even when SU(3) breaking is taken into account. We have...

Source: http://arxiv.org/abs/0912.3561v2

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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Various phenomenological studies indicate that the mixing angle $\theta_{K_1}$ of $K_{1A}$ and $K_{1B}$, the strange partners of the axial-vector mesons $a_1(1260)$ and $b_1(1235)$, respectively, lies in the vicinity of $35^\circ$ or $55^\circ$, but whether this angle is larger or smaller than $45^\circ$ still remains controversial. When the $f_1(1285)$-$f_1(1420)$ mixing angle $\theta_{^3P_1}$ and the $h_1(1170)$-$h_1(1380)$ mixing angle $\theta_{^1P_1}$ are determined from the mass relations,...

Source: http://arxiv.org/abs/1110.2249v1

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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The $K\to\pi\pi$ decay amplitudes are studied within the framework of generalized factorization in which the effective Wilson coefficients are gauge-invariant, renormalization-scale and -scheme independent while factorization is applied to the tree-level hadronic matrix elements. Nonfactorized contributions to the hadronic matrix elements of (V-A)(V-A) four-quark operators, which are needed to account for the suppression of the $\Delta I=3/2 K\to\pi\pi$ amplitude $A_2$ and the enhancement of...

Source: http://arxiv.org/abs/hep-ph/9906403v3

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Sep 22, 2013
09/13

by
Hai-Yang Cheng

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Hadronic charmless B decays and their nonfactorizable effects are reviewed.

Source: http://arxiv.org/abs/hep-ph/9807323v1

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Sep 20, 2013
09/13

by
Hai-Yang Cheng

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Final-state rescattering effects on direct CP violation in charmless hadronic B decays and on the polarization anomaly in $B\to\phi K^*$ are discussed.

Source: http://arxiv.org/abs/hep-ph/0410314v1

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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In pure chiral perturbation theory (ChPT) the couplings of higher order Lagrangian terms are running parameters and hence can be determined only empirically from various low-energy hadronic processes. While this scenario works well for strong interactions, it is unsatisfactory for nonleptonic and radiative nonleptonic weak interactions: It is impossible, from the outset, to determine all unknown higher-order chiral couplings by experiment; theory is tested only by certain chiral constraints...

Source: http://arxiv.org/abs/hep-ph/9210209v1

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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Contrary to what has been often claimed in the literature, we clarify that the hard photon-gluon cross section $\gg_{\rm hard}(x)$ in polarized deep inelastic scattering calculated in the gauge-invariant factorization scheme does {\it not} involve any soft contributions and hence it is genuinely {\it hard}. We show that the polarized proton structure function $g_1^p(x)$ up to the next-to-leading order of $\alpha_s$ is independent of the factorization convention, e.g., the gauge-invariant or...

Source: http://arxiv.org/abs/hep-ph/9512267v1

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Applications of QCD factorization to $B\to\phi K$, charmless $B\to VV$, $B\to J/\psi K(K^*)$ and semi-inclusive decays $B\to MX$ are discussed.

Source: http://arxiv.org/abs/hep-ph/0110026v1

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Sep 17, 2013
09/13

by
Hai-Yang Cheng

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Charmless 3-body decays of $B$ mesons are studied using a simple model based on the framework of the factorization approach. We have identified a large source of the nonresonant signal in the matrix elements of scalar densities, e.g. $$. This explains the dominance of the nonresonant background in $B\to KKK$ decays, the sizable nonresonant fraction of order $(35\sim 40)%$ in $K^-\pi^+\pi^-$ and $\bar K^0\pi^+\pi^-$ modes and the smallness of nonresonant rates in $B\to \pi\pi\pi$ decays. We have...

Source: http://arxiv.org/abs/0711.1416v2

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Charmed meson decays into a pseudoscalar meson P and a tensor meson T are studied. The charm to tensor meson transition form factors are evaluated in the Isgur-Scora-Grinstein-Wise (ISGW) quark model. It is shown that the Cabibbo-allowed decay $D_s^+\to f_2(1270)\pi^+$ is dominated by the W-annihilation contribution and has the largest branching ratio in $D\to TP$ decays. We argue that the Cabibbo-suppressed mode $D^+\to f_2(1270)\pi^+$ should be suppressed by one order of magnitude relative to...

Source: http://arxiv.org/abs/hep-ph/0303195v1

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Sep 20, 2013
09/13

by
Hai-Yang Cheng

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An overview of exclusive two-body and three-body baryonic B decays is given. The threshold enhancement effect in the dibaryon invariant mass and the angular distributions in the dibaryon rest frame are stressed and explained. Weak radiative baryonic B decays mediated by the electromagnetic penguin process $b\to s\gamma$ are discussed. Apart from the first observation of the radiative penguin decay $B^-\to\Lambda\bar p\gamma$ with the baryonic final state, the decay $B^-\to...

Source: http://arxiv.org/abs/hep-ph/0607061v1

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Sep 22, 2013
09/13

by
Hai-Yang Cheng

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The status of exclusive two-body and three-body baryonic B decays is reviewed. The threshold enhancement effect in the dibaryon invariant mass and the angular distributions in the dibaryon rest frame are stressed and explained. Weak radiative baryonic B decays mediated by the electromagnetic penguin process $b\to s\gamma$ are discussed. Puzzles with the correlation observed in $B^-\to p\bar pK^-$ decay and the unexpectedly large rate observed for $B\to\Lambda_c\bar\Lambda_cK$ are examined. The...

Source: http://arxiv.org/abs/hep-ph/0603003v1

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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The proton spin problem triggered by the EMC experiment and its present status are closely examined. Recent experimental and theoretical progresses and their implications are reviewed. It is pointed out that the sign of the sea-quark polarization generated perturbatively by hard gluons via the anomaly mechanism is predictable: It is negative if the gluon spin component is positive. We stress that the polarized nucleon structure function $g_1(x)$ is independent of the $k_\perp$-factorization...

Source: http://arxiv.org/abs/hep-ph/9607254v2

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Sep 19, 2013
09/13

by
Hai-Yang Cheng

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Implications of recent CLEO measurements of hadronic charmless B decays are discussed.

Source: http://arxiv.org/abs/hep-ph/9912372v1

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Sep 20, 2013
09/13

by
Hai-Yang Cheng

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Strong and weak decays of pentaquarks are studied in the framework of the light-front approach.

Source: http://arxiv.org/abs/hep-ph/0410315v1

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Sep 21, 2013
09/13

by
Hai-Yang Cheng

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Final-state rescattering effects on the hadronic B decays and their impact on direct and mixing-induced CP asymmetries are examined. Implications for some phenomenologies are briefly discussed.

Source: http://arxiv.org/abs/hep-ph/0508063v2

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Jun 28, 2018
06/18

by
Hai-Yang Cheng

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This is basically the update of [arXiv:0809.1869], a review on charmed baryon physics around 2007. Topics of this review include the spectroscopy, strong decays, lifetimes, nonleptonic and semileptonic weak decays, and electromagnetic decays of charmed baryons.

Topics: High Energy Physics - Phenomenology, Nuclear Theory, High Energy Physics - Lattice, High Energy...

Source: http://arxiv.org/abs/1508.07233

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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The U(1) Goldberger-Treiman (GT) relation for the axial charge $g_A^0$ is reexamined. It is stressed that the isosinglet GT relation in terms of the $\eta_0$ holds irrespective of the quark masses and the axial anomaly. We pointed out that the identification of the $\eta_0-N$ and $\dk-N$coupling terms with the quark and gluon spin components respectively in a proton is possible but valid only in the chiral-invariant factorization scheme. In general, the two-component U(1) GT relation can be...

Source: http://arxiv.org/abs/hep-ph/9510280v1

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Sep 19, 2013
09/13

by
Hai-Yang Cheng

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The $\Delta I=1/2$ rule and direct CP violation $\epsilon'/\epsilon$ in kaon decays are studied within the framework of the effective Hamiltonian approach in conjunction with generalized factorization for hadronic matrix elements. We identify two principal sources responsible for the enhancement of A0/A_2: the vertex-type as well as penguin-type corrections to the matrix elements of four-quark operators, which render the physical amplitude renormalization-scale and -scheme independent, and the...

Source: http://arxiv.org/abs/hep-ph/9911202v1

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Sep 21, 2013
09/13

by
Hai-Yang Cheng

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Owing to a different treatment of the vacuum alignment, the strong CP-violating Lagrangian obtained by Di Vecchia, Veneziano and Witten (DVW) 3 decades ago do not look quite the same as the one originally derived by Baluni at the quark or hadron level. We show that they are consistent with each other and emphasize that, within the DVW approach, the $\theta G\tilde G$ term is not entirely removed away after the vacuum is rotated from the CP-odd state to the CP-even one; strong CP violation...

Source: http://arxiv.org/abs/1008.4409v2

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Implications of recent measurements of hadronic charmless B decays are discussed.

Source: http://arxiv.org/abs/hep-ph/0008285v1

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Based on SU(3) flavor symmetry, many of the quark-graph amplitudes in two-body nonleptonic decays of charmed mesons can be extracted from experiment, which enable us to see the relevance and importance of weak annihilation topologies and to determine the complex parameters $a_1$ and $a_2$ to test the factorization approach. It is found that $a_2$ in $D\to \bar K^*\pi$ and $D\to \bar K\rho$ can be different by a factor of 2, indicating that nonfactorizable corrections to the latter are far more...

Source: http://arxiv.org/abs/hep-ph/0202254v2

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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The long distance vector-meson-dominance (VMD) effects on the weak radiative decays $\bb\to\rho\gamma$ and $\bb^0\to D^{*0}\gamma$ are studied. For $\bb\to\rho\gamma$ decays, the VMD contribution is $(10-20)\%$ of the short-distance penguin amplitude. The pole effect is as important as the VMD one in the decay $B^-\to\rho^-\gamma$, but it is suppressed in $\bb^0\to \rho^0\gamma$. The branching ratio of $\bb\to\rho\gamma$, estimated to be of order $10^{-6}$, strongly depends on the sign of the...

Source: http://arxiv.org/abs/hep-ph/9411330v1

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Sep 22, 2013
09/13

by
Hai-Yang Cheng

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Hadronic B decays containing an parity-even charmed meson in the final state are studied. Specifically we focus on the Cabibbo-allowed decays $\bar B\to D^{**} \pi(\rho), D^{**}\bar D_s^{(*)}, \bar D^{**}_sD^{(*)}$ and $\bar B_s\to D_s^{**}\pi(\rho)$, where $D^{**}$ denotes generically a p-wave charmed meson. The $B\to D^{**}$ transition form factors are studied in the improved version of the Isgur-Scora-Grinstein-Wise quark model. We apply heavy quark effective theory and chiral symmetry to...

Source: http://arxiv.org/abs/hep-ph/0307168v3

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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Final-state rescattering effects on the hadronic B decays and their impact on direct CP violation are examined. The phenomenology of the polarization anomaly in $B\to\phi K^*$ decays is discussed.

Source: http://arxiv.org/abs/hep-ph/0411340v1

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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The isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$ and their mixing are studied. Two recent lattice results are employed as the starting point; one is the approximate SU(3) symmetry in the scalar sector above 1 GeV for the connected insertion part without $q\bar q$ annihilation, and the other is the scalar glueball mass at 1710 MeV in the quenched approximation. In the SU(3) symmetry limit, $f_0(1500)$ becomes a pure SU(3) octet and is degenerate with $a_0(1450)$, while...

Source: http://arxiv.org/abs/hep-ph/0609229v1

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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Form factors for $P\to P$ and $P\to V$ transitions due to the valence-quark configuration are calculated directly in the physical time-like range of momentum transfer within the light-front quark model. It is pointed out that the Bauer-Stech-Wirbel type of light-front wave function fails to give a correct normalization for the Isgur-Wise function at zero recoil in $P\to V$ transition. Some of the $P\to V$ form factors are found to depend on the recoiling direction of the daughter mesons...

Source: http://arxiv.org/abs/hep-ph/9608446v1

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Sep 20, 2013
09/13

by
Hai-Yang Cheng

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Cabibbo-allowed charmed meson decays into a pseudoscalar meson and an axial-vector meson are studied. The charm to axial-vector meson transition form factors are evaluated in the Isgur-Scora-Grinstein-Wise quark model. The dipole momentum dependence of the $D\to K$ transition form factor and the presence of a sizable long-distance $W$-exchange are the two key ingredients for understanding the data of $D\to \bar Ka_1$. The $K_{1A}-K_{1B}$ mixing angle of the strange axial-vector mesons is found...

Source: http://arxiv.org/abs/hep-ph/0301198v1

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Sep 19, 2013
09/13

by
Hai-Yang Cheng

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Armed with the information on the form factor $\fdpi(0)$ inferred from recent CLEO measurements of SU(3)-breaking effects in charmed meson decays, we have studied the form factor $\fbpi$. In the heavy quark limit, $\fbpi(q^2)$ is related to $\fdpi(q^2)$ in the kinematic region close to zero recoil. Assuming pole dominance for its $q^2$ dependence, $\fbpi(0)$ is estimated to be $\approx 0.39\,.$ If the requirement of heavy quark symmetry is relaxed so that it applies only to soft pion emissions...

Source: http://arxiv.org/abs/hep-ph/9405226v1

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Sep 19, 2013
09/13

by
Hai-Yang Cheng

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Status of nonfactorizable effects in exclusive hadronic weak decays of $D$ and $B$ mesons is reviewed.

Source: http://arxiv.org/abs/hep-ph/9506340v1

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Sep 22, 2013
09/13

by
Hai-Yang Cheng

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A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find that bottom-baryon lifetimes follow the pattern $\tau(\Omega_b)\simeq\tau(\Xi_b^-)>\tau(\Lambda_b)\simeq\tau(\Xi_b^0)$. However, neither the lifetime ratio $\tau(\Lambda_b)/\tau( B_d)$ nor the absolute decay rates of the $\Lambda_b$ baryon and $B$ mesons...

Source: http://arxiv.org/abs/hep-ph/9704260v2

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Based on the measurements of $(D_s^+,D^+)\to f_0(1370)\pi^+$ we determine, in a model independent way, the allowed $s\bar s$ content in the scalar meson $f_0(1370)$. We find that, on the one hand, if this isoscalar resonance is a pure $n\bar n$ state [ $n\bar n\equiv(u\bar u+d\bar d)/\sqrt{2} ]$, a very large $W$-annihilation term will be needed to accommodate $D_s^+\to f_0(1370)\pi^+$. On the other hand, the $s\bar s$ component of $f_0(1370)$ should be small enough to avoid excessive $D_s^+\to...

Source: http://arxiv.org/abs/hep-ph/0212361v1

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Sep 21, 2013
09/13

by
Hai-Yang Cheng

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CP violation due to interference between $K_L$ and $K_S$ decays into $\pi ^+\pi^-\gamma$ is analyzed in the Standard Model. The CP-violating parameter $\epsilon'_{+- \gamma}$, which is the difference between $\eta_{+-\gamma}$ and $\eta_{+-}$, receives dominant contributions from $K^0-\bar{K}^0$ mixing and the gluon penguin diagram; its magnitude is calculated to be $10^{-2}\epsilon$ at a typical region of the Dalitz plot. Genuine direct CP violation in $K_L\to\pi^+ \pi^-\gamma$ decay...

Source: http://arxiv.org/abs/hep-ph/9305324v1

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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The $\Delta I=1/2$ rule and direct CP violation $\epsilon'/\epsilon$ in kaon decays are studied within the framework of the effective Hamiltonian approach in conjunction with generalized factorization for hadronic matrix elements.

Source: http://arxiv.org/abs/hep-ph/0008284v1

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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We have systematically investigated the semi-inclusive B decays $B\to MX$, which are manifestations of the quark decay $b \to Mq$, within a framework inspired by QCD-improved factorization. These decays are theoretically clean and have distinctive experimental signatures. We focus on a class of these that do not require any form factor information and therefore may be especially suitable for extracting information on the angles $\alpha$ and $\gamma$ of the unitarity triangle. The strong phase...

Source: http://arxiv.org/abs/hep-ph/0109259v1

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Sep 23, 2013
09/13

by
Hai-Yang Cheng

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Weak current-induced baryonic form factors at zero recoil are evaluated in the rest frame of the heavy parent baryon using the nonrelativistic quark model. Contrary to previous similar work in the literature, our quark model results do satisfy the constraints imposed by heavy quark symmetry for heavy-heavy baryon transitions. Assuming a dipole $q^2$ behavior, we have applied the quark model form factors to nonleptonic, semileptonic and weak radiative decays of the heavy baryons.

Source: http://arxiv.org/abs/hep-ph/9608445v1

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Status of nonfactorizable effects in hadronic charmless B decays is reviewed. Implications of new CLEO measurements on $B^0\to\pi^+\pi^-$ and $B\to\eta' K$ are discussed. Nonfactorizable effects due to color ocet 4-quark operators are calculated using renormalization group improved QCD sum rules. The resultant B-meson lifetime ratio $\tau(B^-)/\tau(B_d)$ agrees with experiment.

Source: http://arxiv.org/abs/hep-ph/9809284v1

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Jul 20, 2013
07/13

by
Hai-Yang Cheng

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A way of circumventing the gauge and infrared problems with effective Wilson coefficients is shown. Implications of experimentally measured charmless $B$ decays are discussed.

Source: http://arxiv.org/abs/hep-ph/9902378v1

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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The nonleptonic weak decays of charmed mesons into a scalar meson and a pseudoscalar meson are studied. The scalar mesons under consideration are $\sigma$ [or $f_0(600)$], $\kappa$, $f_0(980)$, $a_0(980)$ and $K^*_0(1430)$. A consistent picture provided by the data implies that the light scalars below or near 1 GeV form an SU(3) flavor nonet and are predominately the $q^2\bar q^2$ states, while the scalar mesons above 1 GeV can be described as a $q\bar q$ nonet. Hence, we designate $q^2\bar...

Source: http://arxiv.org/abs/hep-ph/0212117v3

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Sep 21, 2013
09/13

by
Hai-Yang Cheng

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We employ two simple and robust results to constrain the mixing matrix of the isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$: one is the approximate SU(3) symmetry empirically observed in the scalar sector above 1 GeV and confirmed by lattice QCD, and the other is the scalar glueball mass at 1710 MeV in the quenched approximation. In the SU(3) symmetry limit, $f_0(1500)$ becomes a pure SU(3) octet and is degenerate with $a_0(1450)$, while $f_0(1370)$ is mainly an SU(3) singlet...

Source: http://arxiv.org/abs/0901.0741v1

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Sep 21, 2013
09/13

by
Hai-Yang Cheng

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A brief review on the theoretical status of hadronic charm decays is presented. We emphasize the analyses based on the diagrammatic approach and the connection of weak annihilation with final-state rescattering. The topics on the $D^0$-$\bar D^0$ mixing and the baryonic charm decay $D_s^+\to p\bar n$ are sketched.

Source: http://arxiv.org/abs/1011.0790v3

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Sep 18, 2013
09/13

by
Hai-Yang Cheng

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Charmless 3-body decays of B mesons are studied in a simple model based on the factorization approach. We have identified two distinct sources of nonresonant contributions: a small contribution from the tree transition and a large source of the nonresonant signal in the matrix elements of scalar densities, e.g., $$, induced from the penguin transition. This explains the dominance of the nonresonant background in $B\to KKK$ decays, the sizable nonresonant fraction in $K^-\pi^+\pi^-$ and $\bar...

Source: http://arxiv.org/abs/0806.2895v2

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75

Sep 17, 2013
09/13

by
Hai-Yang Cheng

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The recent measurements of the color-suppressed modes $\bar B^0\to D^{(*)0}\pi^0$ imply non-vanishing relative final-state interaction (FSI) phases among various $\bar B\to D\pi$ decay amplitudes. Depending on whether or not FSIs are implemented in the topological quark-diagram amplitudes, two solutions for the parameters $a_1$ and $a_2$ are extracted from data using various form-factor models. It is found that $a_2$ is not universal: $|a_2(D\pi)|= 0.40-0.55$ and $|a_2(D^*\pi)|= 0.25-0.35$ with...

Source: http://arxiv.org/abs/hep-ph/0108096v3