All Results

Reanalysis of the Four-Quark Operators Relevant to #3;b Lifetime from QCD Sum Rule

Chao-Shang Huang; Chun Liu; Shi-Lin ZhuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Λb matrix element of four-quark operator relevant to its lifetime is reanalyzed by QCD sum rule. The new ingredients introduced are that (1) more vacuum condensates are considered; (2) different quark-hadron duality is adopted; and (3) the possible deviation from the vacuum saturation assumption for the four quark condensates is considered. With κ1 = 4 the related hadronic parameter r is calculated to be (3.6 ± 0.9), and the lifetime ratio τ (Λb)/τ (B0) = (0.83 ± 0.04), which is consistent with the experimental data. |

Decay Widths of Excited Heavy Mesons From QCD Sum Rules at the Leading Order of HQET

Yuan-Ben Dai; Chao-Shang Huang; Ming-Qiu Huang; Hong-Ying Jin; Chun LiuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

The widths for pionic decays of lowest two excited doublets (0+, 1+) and(1+, 2+) of heavy mesons are studied with QCD sum rules in the leading order of heavy quark effective theory. The ambiguity due to presence of two distinct 1+ states are solved. The soft pion approximation is not used. |

Q C D Sum R ules for M asses ofExcited H eavy M esons

Yuan-Ben Dai; Chao-Shang Huang; Ming-Qiu Huang; Chun LiuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

The m asses of excited heavy m esons are studied with sum rules in the heavy quark e#11;ective theory.A setofinterpolating currentscreating (annihilating) excited heavy m esonswith arbitrary spin and parity are proposed and their propertiesarediscussed.Num ericalresultsattheleading orderofthe O (1=m Q ) expansion are obtained for the lowest doublets (0+ ;1+ ) and(1+ ;2+ ). |

Embedding Flipped SU(5) into SO(10)

Chao-Shang Huang; Tianjun Li; Chun Liu; Jonathan P. Shock; Feng Wu; Yue-Liang WuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

We embed the flipped SU(5) models into the SO(10) models. After the SO(10) gauge symmetry is broken down to the flipped SU(5)譛(1)X gauge symmetry, we can split the five/one-plets and ten-plets in the spinor 16 and 16 Higgs fields via the stable sliding singlet mechanism. As in the flipped SU(5) models, these ten-plet Higgs fields can break the flipped SU(5) gauge symmetry down to the Standard Model gauge symmetry. The doublet-triplet splitting problem can be solved naturally by the missing partner mechanism, and the Higgsino-exchange mediated proton decay can be suppressed elegantly. Moreover, we show that there exists one pair of the light Higgs doublets for the electroweak gauge symmetry breaking. Because there exist two pairs of additional vector-like particles with similar intermediate-scale masses, the SU(5) and U(1)X gauge couplings can be unified at the GUT scale which is reasonably (about one or two orders) higher than the SU(2)L ?SU(3)C unification scale. Furthermore, we briefly discuss the simplest SO(10) model with flipped SU(5) embedding, and point out that it can not work without fine-tuning. |

Ds(2317) and Ds(2457) from HQET Sum Rules

Yuan-Ben Dai; Chao-Shang Huang; Chun Liu ; Shi-Lin ZhuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Within the framework of the heavy quark effective theory, QCD sum rules are used to calculate the masses of p-wave ?cs states. The results for 0+ and 1+ states with the angular momentum of the light component jl = 1/2 are consistent with the experimental values for Ds(2317) and Ds(2457), respectively. |

Understanding the D+ sJ(2317) and D+ sJ(2460) with Sum Rules in HQET

Yuan-Ben Dai; Chao-Shang Huang; Chun Liu; Shi-Lin ZhuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

In the framework of heavy quark effective theory we use QCD sum rules to calculate the masses of the ?cs (0+, 1+) and (1+, 2+) excited states. The results are consistent with that the states DsJ (2317) and DsJ (2460) observed by BABAR and CLEO are the 0+ and 1+ states in the jl =12+doublet. |

NON-UNIVERSAL GAUGINO MASSES IN SUPERSYMMETRIC SO(10)

Nidal Chamoun; Chao-Shang Huang; Chun Liu; Xiao-Hong WuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

We consider SUSY SO(10) models in which SUSY breaking occurs via an F-term which does not transform as an SO(10) singlet. This results in non-universal GUT-scale gaugino masses leading to a different pattern of sparticle masses from what is expected in the minimal supergravity model (mSUGRA).We study three breaking chains of SO(10) down to the standard model through SU(4)×SU(2)×SU(2), SU(2)×SO(7) and ‘flipped’ SU(5) achieved by the representations 54 and 210 which appear in the symmetric product of two SO(10) adjoints. We examine the phenomenological implications of the different boundary conditions corresponding to the different breaking chainsand present the sparticle spectrum. |

1/mQ Corrections to the Heavy-to-Light-Vector Transitions in the HQET

Chao-Shang Huang; Chun Liu; Chi-Tau YanSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Within the HQET, the heavy to light vector meson transitions are systematically analyzed to the order of 1/mQ. Besides the four universal functions at the leading order, there are twenty-two independent universal form factors at the order of 1/mQ. Both the semileptonic decay B → #26; which is relevant to the |Vub| extraction, and the penguin induced decay B → K? which is important to new physics discovering, depend on these form factors.Phenomenological implications are discussed. |

[1 Pages/ 8 Totals]