作者机构：
[Wang, Chao; Wang, Zhen-Yang; Guo, Xin-Heng] Beijing Normal Univ, Coll Nucl Sci & Technol, Beijing 100875, Peoples R China.;[Zhang, Zhen-Hua] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Wang, Chao] Northwestern Polytech Univ, Ctr Ecol & Environm Sci, Xian 710072, Shaanxi, Peoples R China.
通讯机构：
[Guo, Xin-Heng] B;Beijing Normal Univ, Coll Nucl Sci & Technol, Beijing 100875, Peoples R China.
摘要：
We study the localized direct CP violation in the hadronic decays B±→ρ0(ω)π±→π+π−π±, including the effect caused by an interesting mechanism involving the charge symmetry violating mixing between ρ0 and ω in the QCD factorization approach. We find that ρ−ω mixing makes the localized integrated CP asymmetry move toward the negative direction when the low invariant mass of π+π− [ m(π+π−)low] is near ρ0(770). The localized integrated direct CP violation obtained in the QCD factorization approach varies from −0.0724 to −0.0389 in the ranges of parameters when 0.750<m(π+π−)low<0.800 GeV. This result, especially the sign, agrees with the experimental data. We also calculate the localized integrated direct CP violating asymmetries in the QCD factorization approach in the regions 0.470<m(π+π−)low<0.770 GeV and 0.770<m(π+π−)low<0.920 GeV. We find that these results agree with the experimental data and are more accurate than the results obtained through the naive factorization approach. It is more clear that ρ−ω mixing contributes to the sign change in these two regions.
作者机构：
[Zhang, Zhen-Hua] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Zhang, Zhen-Hua] Univ South China, Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Hunan, Peoples R China.;[Wang, Chao; Guo, Xin-Heng] Beijing Normal Univ, Coll Nucl Sci & Technol, Beijing 100875, Peoples R China.
通讯机构：
[Zhang, Zhen-Hua] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
关键词：
CP violation;Heavy baryon;Bottom quark
摘要：
We propose a new mechanism which can introduce large CP asymmetries in the phase spaces of three-body decays of heavy baryons. In this mechanism, a large CP asymmetry is induced by the interference of two intermediate resonances, which subsequently decay into two different combinations of final particles. We apply this mechanism to the decay channel Lambda(0)(b) -> p pi(0)pi(-), and find that the differential CP asymmetry can reach as large as 50%, while the regional CP asymmetry can reach as large as 16% in the interference region of the phase space. (C) 2015 The Authors. Published by Elsevier B.V.
作者机构：
[Zhang Zhen-Hua] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Zhang Zhen-Hua; Lu, Gang] Univ South China, Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Peoples R China.;[Wei Ke-Wei; Lu, Gang] Henan Univ Technol, Coll Sci, Zhengzhou 450001, Peoples R China.;[Wei Ke-Wei] Anyang Normal Univ, Coll Phys & Elect Engn, Anyang 455002, Peoples R China.
通讯机构：
[Zhang Zhen-Hua] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
X(3872);mass degeneracy;B meson
摘要：
The spin is an important property of a particle. Although it is unlikely, there is still a possibility that two particles with different spins share similar masses. In this paper, we propose a method to probe this kind of mass degeneracy of particles with different spins. We use the cascade decay B+→X(3872)K+, X(3872)→D+D- to illustrate our method. It can be seen that the possible mass degeneracy of X(3872) can lead to interesting behavior in the corresponding cascade decay.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2015年75(11):1-11 ISSN：1434-6044
通讯作者：
Wang, Chao
作者机构：
[Wang, Chao; Wang, Zhen-Yang; Guo, Xin-Heng] Beijing Normal Univ, Coll Nucl Sci & Technol, Beijing 100875, Peoples R China.;[Zhang, Zhen-Hua] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, Chao] B;Beijing Normal Univ, Coll Nucl Sci & Technol, Beijing 100875, Peoples R China.
摘要：
We study the localized direct CP violation in the hadronic decays
$$B^\pm \rightarrow \rho ^0 (\omega )\pi ^\pm \rightarrow \pi ^+ \pi ^-\pi ^\pm $$
, including the effect caused by an interesting mechanism involving the charge symmetry violating mixing between
$$\rho ^0$$
and
$$\omega $$
. We calculate the localized integrated direct CP violation when the low invariant mass of
$$\pi ^+\pi ^-$$
[
$$m(\pi ^+\pi ^-)_{\mathrm{low}}$$
] is near
$$\rho ^0(770)$$
. For the five models of form factors investigated, we find that the localized integrated direct CP violation varies from
$$-0.0752$$
to
$$-0.0290$$
in the ranges of parameters in our model when
$$0.750<m(\pi ^+\pi ^-)_{\mathrm{low}}<0.800$$
GeV. This result, especially the sign, agrees with the experimental data and is independent of the form factor models. The new experimental data shows that the signs of the localized integrated CP asymmetries in the regions
$$0.470<m(\pi ^+\pi ^-)_{\mathrm{low}}<0.770$$
and
$$0.770<m(\pi ^+\pi ^-)_{\mathrm{low}}<0.920$$
GeV are positive and negative, respectively. We find that
$$\rho $$
–
$$\omega $$
mixing makes the localized integrated CP asymmetry move toward the negative direction, and therefore contributes to the sign change in those two regions. This behavior is also independent of the form factor models. We also calculate the localized integrated direct CP violating asymmetries in the regions
$$0.470<m(\pi ^+\pi ^-)_{\mathrm{low}}<0.770$$
,
$$0.770<m(\pi ^+\pi ^-)_{\mathrm{low}}<0.920$$
and the whole region
$$0.470<m(\pi ^+\pi ^-)_{\mathrm{low}}<0.920$$
GeV and find that they agree with the experimental data in some models of the form factors.
摘要：
In the framework of QCD factorization we study the direct CP violation in B→ρ0(ω)V→π+π−V ( V is a vector meson) via the ρ−ω mixing mechanism. We find that the CP violation can be enhanced by ρ−ω mixing when the masses of the π+π− pairs are in the vicinity of the ω resonance. For the decay channel of B−→ρ0(ω)ρ−→π+π−ρ−, the maximum CP violation can reach 18%. We also discuss the possibility to observe the CP violation at the LHC.
摘要：
In the perturbative QCD (PQCD) approach, we study the direct CP violation in B-0,B-+/- --> rho(0)(omega)pi(0,+/-) --> pi(+)pi(-)pi(0,+/-) via the rho-omega mixing mechanism. We find that the CP violation can be enhanced due to a large strong phase difference when the masses of the pi(+)pi(-) pairs are in the vicinity of the omega resonance. Taking into account the rho-omega mixing, we also compare the CP violation from the naive factorization approach, QCD factorization approach, and PQCD approach. Based on the B-0(B) over bar (0) mixing, we discuss the effects of (B) over bar B-0(0) mixing for the total CP violation of B-0 --> rho(0)(omega)pi(0) --> pi(+)pi(-)pi(0), which is time dependent.
