Hindawi Publishing Corporation Advances in High Energy Physics Volume 2016, Article ID 5071671, 11 pages http://dx.doi.org/10.1155/2016/5071671
Research Article Study of the π(1π, 2π) and ππ(1π, 2π) Weak Decays into π·π Junfeng Sun,1 Yueling Yang,1 Jinshu Huang,2 Lili Chen,1 and Qin Chang1 1
Institute of Particle and Nuclear Physics, Henan Normal University, Xinxiang 453007, China College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
2
Correspondence should be addressed to Yueling Yang;
[email protected] Received 20 October 2015; Revised 19 January 2016; Accepted 20 January 2016 Academic Editor: Sally Seidel Copyright Β© 2016 Junfeng Sun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The publication of this article was funded by SCOAP3 . Inspired by the recent measurements on the π½/π(1π) β π·π π, π·π’ πΎβ weak decays at BESIII and the potential prospects of charmonium at high-luminosity heavy-flavor experiments, we study π(1π, 2π) and ππ (1π, 2π) weak decays into final states including one charmed meson plus one light meson, considering QCD corrections to hadronic matrix elements with QCD factorization 0 β0 approach. It is found that the Cabibbo-favored π(1π, 2π) β π·π β π+ , π·π β π+ , π·π’ πΎ decays have large branching ratios β³ 10β10 , which might be accessible at future experiments.
1. Introduction More than forty years after the discovery of the π½/π(1π) meson, the properties of charmonium (bound state of ππ) continue to be the subject of intensive theoretical and experimental study. It is believed that charmonium, resembling bottomonium (bound state of ππ), plays the same role in exploring hadronic dynamics as positronium and/or the hydrogen atom in understanding the atomic physics. Charmonium and bottomonium are good objects to test the basic ideas of QCD [1]. There is a renewed interest in charmonium due to the plentiful dedicated investigation from BES, CLEOc, LHCb, and the studies via decays of the π΅ mesons at π΅ factories. The π(1π, 2π) and ππ (1π, 2π) mesons are π-wave charmonium states below open-charm kinematic threshold and have the well-established quantum numbers of πΌπΊπ½ππΆ = 0+ 1ββ and 0+ 0β+ , respectively. They decay mainly through the strong and electromagnetic interactions. Because the πΊparity conserving hadronic decays π(2π) β πππ½/π(1π), ππ½/π(1π) and ππ (2π) β ππππ (1π) are suppressed by the compact phase space of final states, and because the decays into light hadrons are suppressed by the phenomenological Okubo-Zweig-Iizuka (OZI) rules [2β4], the total widths of π(1π, 2π) and ππ (1π, 2π) are narrow (see Table 1), which
might render the charmonium weak decay as a necessary supplement. Here, we will concentrate on the π(1π, 2π) and ππ (1π, 2π) weak decays into π·π final states, where π denotes the low-lying ππ(3) pseudoscalar and vector meson nonet. Our motivation is listed as follows. From the experimental point of view, (1) some 109 π(1π, 2π) data samples have been collected by BESIII since 2009 [5]. It is inspiringly expected to have about 10 billion π½/π(1π) and 3 billion π(2π) events at BESIII experiment per year of data taking with the designed luminosity [6]: over 1010 π½/π(1π) at LHCb [7], ATLAS [8], and CMS [9] per fbβ1 data in ππ collisions. A large amount of data sample offers a realistic possibility to explore experimentally the charmonium weak decays. Correspondingly, theoretical study is very necessary to provide a ready reference. (2) Identification of the single π· meson would provide an unambiguous signature of the charmonium weak decay into π·π states. With the improvements of experimental instrumentation and particle identification techniques, accurate measurements on the nonleptonic charmonium weak decay might be feasible. Recently, a search for the π½/π(1π) β π·π π, π·π’ πΎβ decays has been performed at BESIII, although signals are unseen for the moment [10]. Of course, the branching ratios for the inclusive charmonium weak decay are tiny within the standard model,
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Advances in High Energy Physics Table 1: The properties of π(1π, 2π) and ππ (1π, 2π) mesons [12].
Meson π(1π) π(2π) ππ (1π) ππ (2π)
πΌπΊπ½ππΆ 0+ 1ββ 0+ 1ββ 0+ 0β+ 0+ 0β+
Mass (MeV) 3096.916 Β± 0.011 +0.012 3686.109β0.014 2983.6 Β± 0.7 3639.4 Β± 1.3
Width 92.9 Β± 2.8 keV 299 Β± 8 keV 32.2 Β± 0.9 MeV +3.2 11.3β2.9 MeV
about 2/(ππ·Ξπ ) βΌ 10β8 and 2/(ππ·Ξππ ) βΌ 10β10 , where π· denotes the neutral charmed meson [11] and Ξπ and Ξππ stand for the total widths of π(1π, 2π) and ππ (1π, 2π) resonances, respectively. Observation of an abnormally large production rate of single charmed mesons in the final state would be a hint of new physics beyond the standard model [11]. From the theoretical point of view, (1) the charm quark weak decay is more favorable than the bottom quark weak decay, because the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements obey |πππ | βͺ |πππ | [12]. Penguin and annihilation contributions to nonleptonic charm quark weak decay, being proportional to the CKM factor |πππ ππ’π | βΌ O(π5 ) with the Wolfenstein parameter π β 0.22 [12], are highly suppressed and hence negligible relative to tree contributions. Both π and π quarks in charmonium can decay individually, which provides a good place to investigate the dynamical mechanism of heavy-flavor weak decay and crosscheck model parameters obtained from the charmed hadron weak decays. (2) There are few works devoted to nonleptonic π½/π(1π) weak decays in the past, such as [13] with the covariant light-cone quark model, [14] with QCD sum rules, and [15β17] with the Wirbel-Stech-Bauer (WSB) model [18]. Moreover, previous works of [13β17] concern mainly the weak transition form factors between the π½/π(1π) and charmed mesons. Fewer papers have been devoted to nonleptonic π(2π) and ππ (1π, 2π) weak decays until now even though a rough estimate of branching ratios is unavailable. In this paper, we will estimate the branching ratios for nonleptonic two-body charmonium weak decay, taking the nonfactorizable contributions to hadronic matrix elements into account with the attractive QCD factorization (QCDF) approach [19]. This paper is organized as follows. In Section 2, we will present the theoretical framework and the amplitudes for π(1π, 2π), ππ (1π, 2π) β π·π decays. Section 3 is devoted to numerical results and discussion. Finally, Section 4 is our summation.
2. Theoretical Framework 2.1. The Effective Hamiltonian. Phenomenologically, the effective Hamiltonian responsible for charmonium weak decay into π·π final states can be written as follows [25]: Heff =
πΊπΉ β πβ π {πΆ (π) π1 (π) + πΆ2 (π) π2 (π)} β2 π1 ,π2 ππ1 π’π2 1 + H.c.,
(1)
where πΊπΉ = 1.166 Γ 10β5 GeVβ2 [12] is the Fermi coupling constant; πππβ 1 ππ’π2 is the CKM factor with π1,2 = π, π ; the Wilson coefficients πΆ1,2 (π), which are independent of one particular process, summarize the physical contributions above the scale of π. The expressions of the local tree fourquark operators are π1 = [π1,πΌ πΎπ (1 β πΎ5 ) ππΌ ] [π’π½ πΎπ (1 β πΎ5 ) π2,π½ ] , π2 = [π1,πΌ πΎπ (1 β πΎ5 ) ππ½ ] [π’π½ πΎπ (1 β πΎ5 ) π2,πΌ ] ,
(2)
where πΌ and π½ are color indices. It is well known that the Wilson coefficients πΆπ could be systematically calculated with perturbation theory and have properly been evaluated to the next-to-leading order (NLO). Their values at the scale of π βΌ O(ππ ) can be evaluated with the renormalization group (RG) equation [25]: πΆ1,2 (π) = π4 (π, ππ ) π5 (ππ , ππ) πΆ1,2 (ππ) ,
(3)
where ππ (ππ , ππ ) is the RG evolution matrix which transforms the Wilson coefficients from scale of ππ to ππ . The expression for ππ (ππ , ππ ) can be found in [25]. The numerical values of the leading-order (LO) and NLO πΆ1,2 in the naive dimensional regularization scheme are listed in Table 2. The values of coefficients πΆ1,2 in Table 2 agree well with those obtained with βeffectiveβ number of active flavors π = 4.15 [25] rather than formula (3). To obtain the decay amplitudes and branching ratios, the remaining works are to evaluate accurately the hadronic matrix elements (HME) where the local operators are sandwiched between the charmonium and final states, which is also the most intricate work in dealing with the weak decay of heavy hadrons by now. 2.2. Hadronic Matrix Elements. Analogous to the exclusive processes with perturbative QCD theory proposed by Lepage and Brodsky [26], the QCDF approach is developed by Beneke et al. [19] to deal with HME based on the collinear factorization approximation and power counting rules in the heavy quark limit and has been extensively used for π΅ meson decays. Using the QCDF master formula, HME of nonleptonic decays could be written as the convolution integrals of the process-dependent hard scattering kernels and universal light-cone distribution amplitudes (LCDA) of participating hadrons. The spectator quark is the heavy-flavor charm quark for charmonium weak decays into π·π final states. It is commonly assumed that the virtuality of the gluon connecting to the heavy spectator is of order Ξ2QCD , where Ξ QCD is the characteristic QCD scale. Hence, the transition form factors between charmonium and π· mesons are assumed to be dominated by the soft and nonperturbative contributions, and the amplitudes of the spectator rescattering subprocess are power-suppressed [19]. Taking ππ β π·π decays, for example, HME can be written as π βπ· σ΅¨ σ΅¨ β¨π·π σ΅¨σ΅¨σ΅¨π1,2 σ΅¨σ΅¨σ΅¨ ππ β© = βπΉπ π ππ β« π»π (π₯) Ξ¦π (π₯) ππ₯, π
(4)
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Table 2: Numerical values of the Wilson coefficients πΆ1,2 and parameters π1,2 for ππ β π·π decay with ππ = 1.275 GeV [12], where π1,2 in [20] is used in the π· meson weak decay. π 0.8ππ ππ 1.2ππ
LO πΆ1 1.335 1.276 1.240
NLO πΆ2 β0.589 β0.505 β0.450
πΆ1 1.275 1.222 1.190
πΆ2 β0.504 β0.425 β0.374
QCDF π1 β 1.275π+π4 +π3β 1.219π β 1.186π+π3
π βπ·
where πΉπ π is the weak transition form factor and ππ and Ξ¦π(π₯) are the decay constant and LCDA of the meson π, respectively. The leading twist LCDA for the pseudoscalar and longitudinally polarized vector mesons can be expressed in terms of Gegenbauer polynomials [23, 24]:
π2 β 0.503πβπ154 βπ154β 0.402π β 0.342πβπ154
(5)
π=0
where π₯ = 1 β π₯; πΆπ3/2 (π§) is the Gegenbauer polynomial,
σ΅¨ σ΅¨ βπ σ΅¨ σ΅¨ Hπ = β¨π σ΅¨σ΅¨σ΅¨π½π σ΅¨σ΅¨σ΅¨ 0β© β¨π· σ΅¨σ΅¨σ΅¨σ΅¨π½π σ΅¨σ΅¨σ΅¨σ΅¨ πβ© = ππ ππ] {πππ]
πΆ13/2 (π§) = 3π§, 3 (5π§2 β 1) , 2
+
π π (ππ + ππ·) ππ] ππ ππ
+
π½ ππ ππ]πΌπ½ πππΌ (ππ + ππ·) } . ππ ππ
H0 = βππ₯ β 2π (π₯2 β 1) , (6)
HΒ± = π Β± 2πβπ₯2 β 1,
.. .
π₯=
πππ is the Gegenbauer moment corresponding to the Gegenbauer polynomials πΆπ3/2 (π§); π0π β‘ 1 for the asymptotic form; and ππ = 0 for π = 1, 3, 5, . . . because of the πΊ-parity invariance of the π, π(σΈ ) , π, π, π meson distribution amplitudes. In this paper, to give a rough estimation, the contributions from higher-order π β₯ 3 Gegenbauer polynomials are not considered for the moment. Hard scattering function π»π (π₯) in (4) is, in principle, calculable order by order with the perturbative QCD theory. At the order of πΌπ 0 , π»π (π₯) = 1. This is the simplest scenario, and one goes back to the naive factorization where there is no information about the strong phases and the renormalization scale hidden in the HME. At the order of πΌπ and higher orders, the renormalization scale dependence of hadronic matrix elements could be recuperated to partly cancel the πdependence of the Wilson coefficients. In addition, part of the strong phases could be reproduced from nonfactorizable contributions. Within the QCDF framework, amplitudes for ππ β π·π decays can be expressed as σ΅¨ σ΅¨ A (ππ σ³¨β π·π) = β¨π·π σ΅¨σ΅¨σ΅¨Heff σ΅¨σ΅¨σ΅¨ ππ β© πΊ σ΅¨ σ΅¨ σ΅¨ σ΅¨ = πΉ πππβ 1 ππ’π2 ππ β¨π σ΅¨σ΅¨σ΅¨π½π σ΅¨σ΅¨σ΅¨ 0β© β¨π· σ΅¨σ΅¨σ΅¨σ΅¨π½π σ΅¨σ΅¨σ΅¨σ΅¨ ππ β© . β2
(8)
The relations among helicity amplitudes and invariant amplitudes π, π, π are
πΆ03/2 (π§) = 1,
πΆ23/2 (π§) =
Previous works π1 π2 1.26 β0.51 1.3 Β± 0.1 β0.55 Β± 0.10 1.274 β0.529
In addition, the HME for the π(1π, 2π) β π·π decays are conventionally expressed as the helicity amplitudes with the decomposition [27, 28],
β
Ξ¦π (π₯) = 6π₯π₯ β ππππΆπ3/2 (π₯ β π₯) ,
Ref. [14, 16, 17] [15] [20]
(7)
ππ β
ππ ππ ππ
=
ππ2
(9) β
2 ππ·
+
2 ππ
2ππ ππ
,
where three scalar amplitudes π, π, π describe π , π, π wave contributions, respectively. The effective coefficient ππ at the order of πΌπ can be expressed as [19] π1 = πΆ1NLO + π2 =
πΆ2NLO
1 NLO πΌπ πΆπΉ LO πΆ + πΆ V, ππ 2 4π ππ 2
1 NLO πΌπ πΆπΉ LO + πΆ + πΆ V, ππ 1 4π ππ 1
(10)
where the color factor πΆπΉ = 4/3; the color number ππ = 3. For the transversely polarized light vector meson, the factor V = 0 in the helicity HΒ± amplitudes beyond the leading twist contributions. With the leading twist LCDA for the pseudoscalar and longitudinally polarized vector mesons, the factor V is written as [19] V = 6 log (
ππ2 1 ) β 18 β ( + π3π) 2 π 2
21 11 + ( β π3π) π1π β π2π + β
β
β
. 2 20
(11)
From the numbers in Table 2, it is found that (1) the values of coefficients π1,2 agree generally with those used in previous works [14β17, 20], (2) the strong phases appear by taking
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nonfactorizable corrections into account, which is necessary for πΆπ violation, and (3) the strong phase of π1 is small due to the suppression of πΌπ and 1/ππ . The strong phase of π2 is large due to the enhancement from the large Wilson coefficients πΆ1 .
π (0) =
2.3. Form Factors. The weak transition form factors between charmonium and a charmed meson are defined as follows [18]: σ΅¨ σ΅¨ β¨π· (π2 ) σ΅¨σ΅¨σ΅¨σ΅¨ππ β π΄ π σ΅¨σ΅¨σ΅¨σ΅¨ ππ (π1 )β©
β
= {(π1 + π2 )π β +
2 ππ2π β ππ·
π2
2 ππ2π β ππ·
π2
ππ } πΉ1 (π2 )
ππ πΉ0 (π2 ) ,
2ππ ππ β
π
βπ
π2
2
π (π )
π½
ππ + ππ·
(12)
ππ π΄ 0 (π2 )
β πππ,π (ππ + ππ·) π΄ 1 (π2 ) ππ β
π
βπ
ππ + ππ· 2ππ ππ β
π
+π
π2
(π1 + π2 )π π΄ 2 (π2 ) ππ π΄ 3 (π2 ) ,
1
πΌ = β2 β« β« {Ξ¦π (πβ β₯ , π₯, 1, β1) πππ¦ Ξ¦π· (πβ β₯ , π₯, 0, 0)} 0
1 ππ₯ ππβ β₯ , π₯ (14)
where ππ¦,π§ is the Pauli matrix acting on the spin indices of the decaying charm quark; π₯ and πβ β₯ denote the fraction of the longitudinal momentum and the transverse momentum of the nonspectator quark, respectively. With the separation of the spin and spatial variables, wave functions can be written as
2ππ π΄ 3 (π2 ) = (ππ + ππ·) π΄ 1 (π2 ) + (ππ β ππ·) π΄ 2 (π2 ) .
(13)
There are four independent transition form factors, πΉ0 (0), π΄ 0,1 (0), and π(0), at the pole of π2 = 0. They could be written as the overlap integrals of wave functions [18]:
β
ππ§ Ξ¦π· (πβ β₯ , π₯, 0, 0)} ππ₯ ππβ β₯ , π΄ 1 (0) =
ππ + ππ ππ + ππ·
πΌ,
2
2
(16)
where the parameter πΌ determines the average transverse 2 quark momentum, β¨π1π |πβ β₯ |π1π β© = πΌ2 . With the NRQCD power counting rules [29], |πβ β₯ | βΌ πV βΌ ππΌπ for heavy quarkonium. Hence, parameter πΌ is approximately taken as ππΌπ in our calculation. Using the substitution ansatz [33], 2 πβ σ³¨β
0
0
2
2 β π2π (π)β βΌ πβπ /2πΌ (2πβ β 3πΌ2 ) ,
πΉ0 (0) = β« β« {Ξ¦ππ (πβ β₯ , π₯, 0, 0)
1
β2
π1π (π)β βΌ πβπ /2πΌ ,
1
π΄ 0 (0) = β« β« {Ξ¦π (πβ β₯ , π₯, 1, 0)
(15)
where the total angular momentum πβ = πΏβ + π 1β + π 2β = π 1β + π 2β = π β because the orbital angular momentum between the valence quarks in π(1π, 2π), ππ (1π, 2π), π· mesons in question have πΏβ = 0; π 1,2 denote the spins of valence quarks in meson; π = 1 and 0 for the π and ππ mesons, respectively. The charm quark in the charmonium state is nearly nonrelativistic with an average velocity V βͺ 1 based on arguments of nonrelativistic quantum chromodynamics (NRQCD) [29β31]. For the π· meson, the valence quarks are also nonrelativistic due to ππ· β ππ + ππ , where the light quark mass ππ’ β ππ β 310 MeV and ππ β 510 MeV [32]. Here, we will take the solution of the SchrΒ¨odinger equation with a scalar harmonic oscillator potential as the wave functions of the charmonium and π· mesons:
where π = π1 β π2 ; ππ denotes the πβs polarization vector. The form factors πΉ0 (0) = πΉ1 (0) and π΄ 0 (0) = π΄ 3 (0) are required compulsorily to cancel singularities at the pole of π2 = 0. There is a relation among these form factors:
β
Ξ¦π· (πβ β₯ , π₯, 0, 0)} ππ₯ ππβ β₯ ,
πΌ,
σ΅¨ Ξ¦ (πβ β₯ , π₯, π, ππ§ ) = π (πβ β₯ , π₯) σ΅¨σ΅¨σ΅¨π , π π§ , π 1 , π 2 β© ,
σ΅¨ σ΅¨ β¨π· (π2 ) σ΅¨σ΅¨σ΅¨σ΅¨ππ β π΄ π σ΅¨σ΅¨σ΅¨σ΅¨ π (π1 , π)β© = βππ]πΌπ½ ππ] ππΌ (π1 + π2 )
ππ β ππ ππ β ππ·
2 πβ β₯ + π₯ππ2 + π₯ππ2
4π₯π₯
,
(17)
one can obtain 2 2 2 { πβ β₯ + π₯ππ + π₯ππ } β π1π (πβ₯ , π₯) = π΄ exp { }, β8πΌ2 π₯π₯ } { 2 2 2 { πβ β₯ + π₯ππ + π₯ππ } β β π2π (πβ₯ , π₯) = π΅π1π (πβ₯ , π₯) { β 1} , 2 6πΌ π₯π₯ { }
(18)
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Table 3: The numerical values of transition form factors at π2 = 0, where uncertainties of this work come from the charm quark mass. Transition
ππ (1π), π(1π) β π·π’,π
ππ (1π), π(1π) β π·π
ππ (2π), π(2π) β π·π’,π ππ (2π), π(2π) β π·π
Reference This work [13]a [21]b [15]c [17]d [17]e This work [13]a [21]b [15]c [17]d [17]e This work This work
πΉ0 (0) 0.85 Β± 0.01 β
β
β
β
β
β
β
β
β
β
β
β
β
β
β
0.90 Β± 0.01 β
β
β
β
β
β
β
β
β
β
β
β
β
β
β
0.62 Β± 0.01 0.65 Β± 0.01
π΄ 0 (0) 0.85 Β± 0.01 0.68 Β± 0.01 +0.02 0.27β0.03 0.40 (0.61) 0.55 Β± 0.02 0.54 0.90 Β± 0.01 0.68 Β± 0.01 0.37 Β± 0.02 0.47 (0.66) 0.71+0.04 β0.02 0.69 0.61 Β± 0.01 0.64 Β± 0.01
π΄ 1 (0) 0.72 Β± 0.01 0.68 Β± 0.01 +0.03 0.27β0.02 0.44 (0.68) +0.09 0.77β0.07 0.80 0.81 Β± 0.01 0.68 Β± 0.01 0.38+0.02 β0.01 0.55 (0.78) 0.94 Β± 0.07 0.96 0.54 Β± 0.01 0.59 Β± 0.02
π(0) 1.76 Β± 0.03 1.6 Β± 0.1 0.81+0.12 β0.08 1.17 (1.82) +0.15 2.14β0.11 2.21 1.55 Β± 0.04 1.8 +0.05 1.07β0.02 1.25 (1.80) 2.30+0.09 β0.06 2.36 1.00 Β± 0.04 0.83 Β± 0.04
a
The form factors are computed with the covariant light-front quark model, where uncertainties come from the decay constant of charmed meson. The form factors are computed with QCD sum rules, where uncertainties are from the Borel parameters. c The form factors are computed with parameter π = 0.4 (0.5) GeV using the WSB model. d The form factors are computed with flavor dependent parameter π using the WSB model. e The form factors are computed with parameter π = ππΌπ using the WSB model. b
where the parameters π΄ and π΅ are the normalization coefficients satisfying the normalization condition, 1 σ΅¨ σ΅¨2 β« β« σ΅¨σ΅¨σ΅¨σ΅¨π (πβ β₯ , π₯)σ΅¨σ΅¨σ΅¨σ΅¨ ππ₯ ππβ β₯ = 1. 0
(19) 2
The numerical values of transition form factors at π = 0 are listed in Table 3. It is found that (1) the model dependence of form factors is large; (2) isospin-breaking effects are negligible and flavor breaking effects are small; and (3) as stated in [18] πΉ0 β π΄ 0 holds within collinear symmetry.
the mixing of pseudoscalar π and πσΈ meson, we will adopt the quark-flavor basis description proposed in [22] and neglect the contributions from possible gluonium compositions; that is, π ππ cos π β sin π )( ), ( σΈ ) = ( sin π cos π ππ π
where ππ = (π’π’ + ππ)/β2 and ππ = π π ; the mixing angle π = (39.3 Β± 1.0)β [22]. The mass relations are ππ2π = ππ2 cos2 π + ππ2σΈ sin2 π
3. Numerical Results and Discussion In the charmonium center-of-mass frame, the branching ratio for the charmonium weak decay can be written as Bπ (ππ σ³¨β π·π) = Bπ (π σ³¨β π·π) =
πcm σ΅¨σ΅¨ σ΅¨2 σ΅¨A (ππ σ³¨β π·π)σ΅¨σ΅¨σ΅¨ , 4πππ2π Ξππ σ΅¨
(20)
πcm σ΅¨σ΅¨ σ΅¨2 σ΅¨A (π σ³¨β π·π)σ΅¨σ΅¨σ΅¨ , 12πππ2 Ξπ σ΅¨
πcm β[ππ2 ,π β (ππ· + ππ)2 ] [ππ2 ,π β (ππ· β ππ)2 ] π
π
2πππ ,π
β
β2ππ
π
πππ
(ππ2σΈ β ππ2 ) cos π sin π,
ππ2π = ππ2 sin2 π + ππ2σΈ cos2 π β
πππ β2ππ
(23)
(ππ2σΈ β ππ2 ) cos π sin π.
π
where the common momentum of final states is
=
(22)
(21) .
The decay amplitudes for A(π β π·π) and A(ππ β π·π) are collected in Appendices A and B, respectively. In our calculation, we assume that the light vector mesons are ideally mixed; that is, π = (π’π’ + ππ)/β2 and π = π π . For
The input parameters, including the CKM Wolfenstein parameters, decay constants, and Gegenbauer moments, are collected in Table 4. If not specified explicitly, we will take their central values as the default inputs. Our numerical results on branching ratios for the nonleptonic two-body π(1π, 2π), ππ (1π, 2π) β π·π weak decays are displayed in Tables 5 and 6, where the uncertainties of this work come from the CKM parameters, the renormalization scale π = (1Β± 0.2)ππ , and hadronic parameters including decay constants and Gegenbauer moments, respectively. For comparison, previous results on π½/π(1π) weak decays [14, 16, 17] with parameters π1 = 1.26 and π2 = β0.51 are also listed in Table 5. The following are some comments.
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Advances in High Energy Physics Table 4: Numerical values of input parameters. +0.023 π΄ = 0.814β0.024 [12] π = 0.353 Β± 0.013 [12] ππ·π’ = 1864.84 Β± 0.07 MeV [12] ππ·π = 1968.30 Β± 0.11 MeV [12] ππΎ = 156.2 Β± 0.7 MeV [12] πππ = (1.34 Β± 0.06) ππ [22]
π = 0.22537 Β± 0.00061 [12] π = 0.117 Β± 0.021 [12] ππ = 1.275 Β± 0.025 GeV [12] ππ·π = 1869.61 Β± 0.10 MeV [12] ππ = 130.41 Β± 0.20 MeV [12] πππ = (1.07 Β± 0.02) ππ [22] ππ = 216 Β± 3 MeV [23] ππ = 215 Β± 5 MeV [23] π π π2π = π2 π = π2 π = 0.25 Β± 0.15 [24] π1πΎ = βπ1πΎ = 0.06 Β± 0.03 [24] β β π1πΎ = βπ1πΎ = 0.03 Β± 0.02 [23] π π π1π = π1 = π1π = π1 = 0
ππ = 187 Β± 5 MeV [23] ππΎβ = 220 Β± 5 MeV [23] π π2 = π2π = 0.15 Β± 0.07 [23] π2πΎ = π2πΎ = 0.25 Β± 0.15 [24] β β π2πΎ = π2πΎ = 0.11 Β± 0.09 [23] π π2 = 0.18 Β± 0.08 [23]
Table 5: Branching ratios for the nonleptonic two-body π½/π(1π) weak decays, where the uncertainties of this work come from the CKM parameters, the renormalization scale π = (1 Β± 0.2)ππ , and hadronic parameters including decay constants and Gegenbauer moments, respectively. The results of [14, 16, 17] are calculated with π1 = 1.26 and π2 = β0.51. The results of [14] are based on QCD sum rules. The numbers in columns of βA,β βB,β βC,β and βDβ are based on the WSB model with flavor dependent π, QCD inspired π = πΌπ π, and universal π = 0.4 GeV and 0.5 GeV, respectively. Final states π·π β π+ π·π β πΎ+ π·πβ π+ π·πβ πΎ+ 0 π· π’ π0 0 π·π’ πΎ0 0 0 π·π’ πΎ 0 π·π’ π 0 π·π’ πσΈ β + π·π π π·π β πΎβ+ π·πβ π+ π·πβ πΎβ+ 0 π· π’ π0 0 π·π’ π 0 π·π’ π 0 π·π’ πΎβ0 0 β0 π·π’ πΎ
Case
Reference [14]
1-a 1-b 1-b 1-c 2-b 2-c 2-a
2.0 Γ 10β10 1.6 Γ 10β11 0.8 Γ 10β11 β
β
β
β
β
β
β
β
β
3.6 Γ 10β11 β
β
β
β
β
β
1.26 Γ 10β9 0.82 Γ 10β10 0.42 Γ 10β10 β
β
β
β
β
β
β
β
β
β
β
β
β
β
β
1.54 Γ 10β10
1-a 1-b 1-b 1-c 2-b 2-b 2-b 2-c 2-a
A 7.41 Γ 10β10 5.3 Γ 10β11 2.9 Γ 10β11 2.3 Γ 10β12 2.4 Γ 10β12 4.0 Γ 10β13 1.39 Γ 10β10 7.0 Γ 10β12 4.0 Γ 10β13 5.11 Γ 10β9 2.82 Γ 10β10 2.16 Γ 10β10 1.3 Γ 10β11 1.8 Γ 10β11 1.6 Γ 10β11 4.2 Γ 10β11 2.1 Γ 10β12 7.61 Γ 10β10
Reference [17] B 7.13 Γ 10β10 5.2 Γ 10β11 2.8 Γ 10β11 2.2 Γ 10β12 2.3 Γ 10β12 4.0 Γ 10β13 1.34 Γ 10β10 6.7 Γ 10β12 4.0 Γ 10β13 5.32 Γ 10β9 2.96 Γ 10β10 2.28 Γ 10β10 1.3 Γ 10β11 1.9 Γ 10β11 1.7 Γ 10β11 4.4 Γ 10β11 2.2 Γ 10β12 8.12 Γ 10β10
(1) There are some differences among the estimates of branching ratios for π½/π(1π) β π·π weak decays (see the numbers in Table 5). These inconsistencies among previous works, although the same values of parameters π1,2 are used, come principally from different values of form factors. Our results are generally in line with the numbers in columns βAβ and βBβ which are favored by [17]. (2) Branching ratios for π½/π(1π) weak decay are about two or more times as large as those for π(2π) decay into the same final states, because the decay width of π(2π) is about three times as large as that of π½/π(1π).
C 3.32 Γ 10β10 2.4 Γ 10β11 1.5 Γ 10β11 1.2 Γ 10β12 1.2 Γ 10β12 2.0 Γ 10β13 7.2 Γ 10β11 3.6 Γ 10β12 2.0 Γ 10β13 1.77 Γ 10β9 0.97 Γ 10β10 0.72 Γ 10β10 4.2 Γ 10β12 6.0 Γ 10β12 5.0 Γ 10β12 1.4 Γ 10β11 7.0 Γ 10β13 2.51 Γ 10β10
Reference [16] D 8.74 Γ 10β10 5.5 Γ 10β11 5.5 Γ 10β11 β
β
β
5.5 Γ 10β12 β
β
β
2.8 Γ 10β10 1.6 Γ 10β12 3.0 Γ 10β13 3.63 Γ 10β9 2.12 Γ 10β10 2.20 Γ 10β10 β
β
β
2.2 Γ 10β11 1.8 Γ 10β11 6.5 Γ 10β11 β
β
β
1.03 Γ 10β9
This work +0.01+0.10+0.01 (1.09β0.01β0.06β0.01 ) Γ 10β9 +0.03+0.59+0.08 (6.18β0.03β0.33β0.08 ) Γ 10β11 +0.03+0.60+0.03 (6.37β0.03β0.34β0.03 ) Γ 10β11 +0.04+0.36+0.05 (3.79β0.04β0.20β0.05 ) Γ 10β12 β12 (3.50+0.02+1.98+0.06 β0.02β0.97β0.06 ) Γ 10 +0.04+2.35+0.11 (4.16β0.04β1.15β0.10 ) Γ 10β13 +0.01+0.81+0.03 (1.44β0.01β0.40β0.03 ) Γ 10β10 +0.01+0.58+0.10 (1.03β0.01β0.28β0.10 ) Γ 10β11 +0.03+3.29+1.72 (5.83β0.03β1.61β1.50 ) Γ 10β13 β9 (3.82+0.01+0.36+0.11 β0.01β0.20β0.11 ) Γ 10 β10 (2.00+0.01+0.19+0.10 β0.01β0.11β0.09 ) Γ 10 +0.01+0.20+0.06 (2.12β0.01β0.11β0.06 ) Γ 10β10 +0.01+0.11+0.06 (1.14β0.01β0.06β0.05 ) Γ 10β11 +0.01+0.61+0.04 (1.08β0.01β0.30β0.04 ) Γ 10β11 β12 (8.10+0.04+4.56+0.50 β0.04β2.25β0.48 ) Γ 10 β11 (1.92+0.01+1.08+0.10 β0.01β0.53β0.10 ) Γ 10 +0.01+0.67+0.07 (1.19β0.01β0.33β0.07 ) Γ 10β12 +0.01+2.30+0.24 (4.09β0.01β1.14β0.23 ) Γ 10β10
(3) Due to the relatively small decay width and relatively large space phases for ππ (2π) decay, branching ratios for ππ (2π) weak decay are some five (ten) or more times as large as those for ππ (1π) weak decay into the same π·π (π·π) final states. (4) Among π(1π, 2π) and ππ (1π, 2π) mesons, ππ (1π) has a maximal decay width and a minimal mass resulting in a small phase space, while π½/π(1π) has a minimal decay width. These facts lead to the smallest [or the largest] branching ratio for ππ (1π) [or π½/π(1π)] weak decay among π(1π, 2π), ππ (1π, 2π) weak decays into the same final states.
Advances in High Energy Physics
7
Table 6: Branching ratios for the nonleptonic two-body π(2π), ππ (1π), and ππ (2π) weak decays, where the uncertainties come from the CKM parameters, the renormalization scale π = (1 Β± 0.2)ππ , and hadronic parameters including decay constants and Gegenbauer moments, respectively. Case 1-a 1-b 1-b 1-c 2-b 2-c 2-a
1-a 1-b 1-b 1-c 2-b 2-b 2-b 2-c 2-a
Final states π·π β π+ π·π β πΎ+ π·πβ π+ π·πβ πΎ+ 0 π·π’ π0 0 0 π·π’ πΎ 0 0 π·π’ πΎ 0 π·π’ π 0 σΈ π·π’ π π·π β π+ π·π β πΎβ+ π·πβ π+ π·πβ πΎβ+ 0 π·π’ π0 0 π·π’ π 0 π·π’ π 0 β0 π·π’ πΎ 0 β0 π·π’ πΎ
π(2π) decay +0.01+0.48+0.03 (5.07β0.01β0.27β0.02 ) Γ 10β10 +0.02+0.33+0.04 (3.43β0.02β0.18β0.04 ) Γ 10β11 +0.01+0.26+0.01 (2.76β0.01β0.15β0.01 ) Γ 10β11 +0.02+0.18+0.02 (1.90β0.02β0.10β0.02 ) Γ 10β12 β12 (1.51+0.01+0.85+0.02 β0.01β0.42β0.02 ) Γ 10 +0.02+1.17+0.05 (2.07β0.02β0.57β0.05 ) Γ 10β13 +0.01+4.04+0.17 (7.15β0.01β1.98β0.16 ) Γ 10β11 +0.03+3.02+0.54 (5.35β0.03β1.48β0.50 ) Γ 10β12 +0.03+3.18+1.68 (5.63β0.03β1.56β1.46 ) Γ 10β13 +0.01+0.15+0.05 (1.67β0.01β0.09β0.05 ) Γ 10β9 +0.05+0.89+0.46 (9.59β0.05β0.50β0.45 ) Γ 10β11 +0.05+0.83+0.26 (8.99β0.05β0.47β0.26 ) Γ 10β11 +0.06+0.48+0.25 (5.15β0.05β0.27β0.24 ) Γ 10β12 +0.02+2.44+0.15 (4.36β0.02β1.21β0.15 ) Γ 10β12 +0.02+1.84+0.20 (3.28β0.02β0.91β0.19 ) Γ 10β12 β12 (9.40+0.05+5.28+0.52 β0.05β2.61β0.50 ) Γ 10 +0.05+2.86+0.31 (5.09β0.05β1.42β0.30 ) Γ 10β13 +0.01+0.98+0.11 (1.74β0.01β0.49β0.10 ) Γ 10β10
Table 7: Classification of the nonleptonic charmonium weak decays. Case 1-a 1-b 1-c 2-a 2-b 2-c
Parameter π1 π1 π1 π2 π2 π2
CKM factor |ππ’π πππ β | βΌ 1 β |ππ’π πππ |, |ππ’π πππ β | βΌ π β |ππ’π πππ | βΌ π2 β |ππ’π πππ | βΌ 1 β |ππ’π πππ |, |ππ’π πππ β | βΌ π β |ππ’π πππ | βΌ π2
(5) Compared with π(1π, 2π) β π·π decays, the corresponding π(1π, 2π) β π·π decays, where π and π have the same flavor structures, are suppressed by the orbital angular momentum and so have relatively small branching ratios. There are some approximative relations Bπ(π½/π(1π) β π·π) β 3Bπ(π½/π(1π) β π·π) and Bπ(π(2π) β π·π) β 3Bπ(π(2π) β π·π). (6) According to the CKM factors and parameters π1,2 , nonleptonic charmonium weak decays could be subdivided into six cases (see Table 7). Case βi-aβ is the Cabibbo-favored one, so it generally has large branching ratios relative to cases βi-bβ and βi-c.β The π2 dominated charmonium weak decays are suppressed by a color factor relative to π1 -dominated ones. Hence, the charmonium weak decays into π·π π and π·π π final states belonging to case β1-aβ usually have relatively large branching ratios; the charmonium weak decays 0 into the π·π’ πΎβ0 final states belonging to case β2cβ usually have relatively small branching ratios. In
ππ (1π) decay +0.01+0.69+0.04 (7.35β0.01β0.39β0.04 ) Γ 10β12 +0.03+0.48+0.06 (4.97β0.03β0.27β0.06 ) Γ 10β13 +0.02+0.41+0.02 (4.39β0.02β0.23β0.02 ) Γ 10β13 +0.03+0.29+0.04 (3.04β0.03β0.16β0.04 ) Γ 10β14 β14 (2.41+0.01+1.36+0.04 β0.01β0.67β0.04 ) Γ 10 +0.04+1.89+0.09 (3.35β0.04β0.93β0.08 ) Γ 10β15 +0.01+0.65+0.03 (1.16β0.01β0.32β0.03 ) Γ 10β12 +0.04+4.89+0.88 (8.66β0.04β2.40β0.82 ) Γ 10β14 +0.04+4.32+2.28 (7.66β0.04β2.12β1.98 ) Γ 10β15 β12 (5.28+0.01+0.50+0.15 β0.01β0.28β0.15 ) Γ 10 +0.01+0.11+0.06 (1.18β0.01β0.06β0.06 ) Γ 10β13 β13 (4.32+0.02+0.41+0.12 β0.02β0.23β0.12 ) Γ 10 +0.01+0.13+0.07 (1.38β0.01β0.07β0.07 ) Γ 10β14 β14 (2.38+0.01+1.35+0.08 β0.01β0.66β0.08 ) Γ 10 +0.01+0.98+0.11 (1.74β0.01β0.48β0.10 ) Γ 10β14 +0.04+4.84+0.47 (8.57β0.04β2.38β0.45 ) Γ 10β15 +0.02+0.85+0.08 (1.50β0.02β0.42β0.08 ) Γ 10β15 β13 (5.20+0.01+2.94+0.29 β0.01β1.44β0.28 ) Γ 10
ππ (2π) decay β11 (3.90+0.01+0.37+0.02 β0.01β0.21β0.02 ) Γ 10 +0.01+0.27+0.04 (2.87β0.01β0.15β0.04 ) Γ 10β12 +0.01+0.20+0.01 (2.13β0.01β0.11β0.01 ) Γ 10β12 +0.02+0.15+0.02 (1.58β0.02β0.08β0.02 ) Γ 10β13 +0.01+0.66+0.02 (1.16β0.01β0.32β0.02 ) Γ 10β13 +0.02+0.97+0.04 (1.73β0.02β0.48β0.04 ) Γ 10β14 +0.01+3.37+0.14 (5.96β0.01β1.65β0.14 ) Γ 10β12 +0.02+2.57+0.46 (4.55β0.02β1.26β0.43 ) Γ 10β13 +0.03+3.40+1.79 (6.02β0.03β1.67β1.56 ) Γ 10β14 +0.01+0.68+0.21 (7.24β0.01β0.38β0.21 ) Γ 10β11 +0.02+0.33+0.17 (3.47β0.02β0.18β0.16 ) Γ 10β12 +0.02+0.39+0.12 (4.13β0.02β0.22β0.12 ) Γ 10β12 +0.02+0.19+0.10 (2.02β0.02β0.11β0.10 ) Γ 10β13 +0.01+1.27+0.08 (2.24β0.01β0.62β0.08 ) Γ 10β13 +0.01+0.94+0.10 (1.67β0.01β0.46β0.10 ) Γ 10β13 β13 (3.28+0.02+1.85+0.18 β0.02β0.91β0.17 ) Γ 10 +0.02+1.23+0.12 (2.18β0.02β0.60β0.12 ) Γ 10β14 +0.01+4.27+0.42 (7.57β0.01β2.10β0.40 ) Γ 10β12
addition, the branching ratio of case β2-aβ (or β2-bβ) is usually larger than that of case β1-bβ (or β1-cβ) due to |π2 /π1 | β₯ π. (7) Branching ratios for the Cabibbo-favored π(1π, 0 β0 2π) β π·π β π+ , π·π β π+ , π·π’ πΎ decays can reach up to 10β10 , which might be measurable in the forthcoming days. For example, π½/π(1π) production cross section can reach up to a few ππ with the LHCb and ALICE detectors at LHC [7, 8]. Therefore, over 1012 π½/π(1π) samples are in principle available per 100 fbβ1 data collected by LHCb and ALICE, corresponding to a 0 β0 few tens of π½/π(1π) β π·π β π+ , π·π β π+ , π·π’ πΎ events for about 10% reconstruction efficiency. (8) There is a large cancellation between the CKM factors β and ππ’π πππ β , which results in a very small ππ’π πππ branching ratio for charmonium weak decays into π·π’ πσΈ state. (9) There are many uncertainties in our results. The first uncertainty from the CKM factors is small due to high precision on the Wolfenstein parameter π with only 0.3% relative errors now [12]. The second uncertainty from the renormalization scale π could, in principle, be reduced by the inclusion of higher order πΌπ corrections. For example, it has been shown [34] that tree amplitudes incorporating with the NNLO corrections are relatively less sensitive to the renormalization scale than the NLO amplitudes. The third uncertainty comes from hadronic parameters, which is expected to be cancelled or reduced with the relative ratio of branching ratios.
8
Advances in High Energy Physics (10) The numbers in Tables 5 and 6 just provide an order of magnitude estimate. Many other factors, such as the final state interactions and π2 dependence of form factors, which are not considered here, deserve many dedicated studies.
0
A (π σ³¨β π·π’ ππ ) = πΊπΉ ππ (ππ β
πππ ) πβπ·π’
β
πππ π΄ 0
0
A (π σ³¨β π·π’ ππ ) = β2πΊπΉ ππ (ππ β
πππ ) πβπ·π’
β
πππ π΄ 0
4. Summary With the anticipation of abundant data samples on charmonium at high-luminosity heavy-flavor experiments, we studied the nonleptonic two-body π(1π, 2π) and ππ (1π, 2π) weak decays into one ground-state charmed meson plus one ground-state light meson based on the low energy effective Hamiltonian. By considering QCD radiative corrections to hadronic matrix elements of tree operators, we got the effective coefficients π1,2 containing partial information of strong phases. The magnitude of π1,2 agrees comfortably with those used in previous works [14β17]. The transition form factors between the charmonium and charmed meson are calculated by using the nonrelativistic wave functions with isotropic harmonic oscillator potential. Branching ratios for π(1π, 2π), ππ (1π, 2π) β π·π decays are estimated roughly. It is found that the Cabibbo-favored π(1π, 2π) β π·π β π+ , π·π β π+ , 0 β0 π·π’ πΎ
β10
decays have large branching ratios β³ 10 promisingly detected in the forthcoming years.
, which are
β πππ ππ’π π2 ,
πππ β ππ’π π2 ,
0
0
A (π σ³¨β π·π’ π) = cos πA (π σ³¨β π·π’ ππ ) β sin π 0
β
A (π σ³¨β π·π’ ππ ) , 0
0
A (π σ³¨β π·π’ πσΈ ) = sin πA (π σ³¨β π·π’ ππ ) + cos π 0
β
A (π σ³¨β π·π’ ππ ) , A (π σ³¨β π·π β π+ ) = βπ
πΊπΉ π π πβ π π {(ππβ β
ππ ) β2 π π ππ π’π 1
πβπ·π
πβπ·
β
2π΄ 2 π 2ππβπ·π β πππ]πΌπ½ ππβπ ππ] πππΌ πππ½ }, ππ + ππ·π ππ + ππ·π
A (π σ³¨β π·π β πΎβ+ ) = βπ
Appendices A. The Amplitudes for π β π·π Decays
+ (ππβ β
ππ ) (ππ β
ππ )
β
(ππ + ππ·π ) π΄ 1
πΊπΉ β2 πβπ·π
β β
ππΎβ ππΎβ πππ β ππ’π π1 {(ππΎ β β
ππ ) (ππ + ππ· ) π΄ 1 π
Consider A (π σ³¨β π·π β π+ ) = β2πΊπΉ ππ (ππ β
ππ ) πβπ·π
β
ππ π΄ 0 A (π σ³¨β
πππ β ππ’π π1 ,
π·π β πΎ+ )
πβπ·π
π·πβ π+ )
πβπ·π
β
ππ π΄ 0
= β2πΊπΉ ππ (ππ β
ππΎ )
πππ β ππ’π π1 ,
β
ππΎ π΄ 0 A (π σ³¨β
= β2πΊπΉ ππ (ππ β
ππ )
β πππ ππ’π π1 ,
A (π σ³¨β π·πβ πΎ+ ) = β2πΊπΉ ππ (ππ β
ππΎ ) πβπ·π
β
ππΎ π΄ 0
β πππ ππ’π π1 ,
0
A (π σ³¨β π·π’ π0 ) = βπΊπΉ ππ (ππ β
ππ ) πβπ·π’
β
ππ π΄ 0
A (π σ³¨β
β πππ ππ’π π2 ,
0 π·π’ πΎ 0 )
πβπ·π’
β
ππΎ π΄ 0
0
= β2πΊπΉ ππ (ππ β
ππΎ )
β πππ ππ’π π2 ,
πβπ·π’
βπ
πΌ π½ β πππ]πΌπ½ ππΎβ ππ] ππΎ β ππ
A (π σ³¨β π·πβ π+ ) = βπ
πππ β ππ’π π2 ,
πβπ·
2π΄ 2 π ππ + ππ·π
2ππβπ·π }, ππ + ππ·π
πΊπΉ π π πβ π π {(ππβ β
ππ ) β2 π π ππ π’π 1
πβπ·π
β
(ππ + ππ·π ) π΄ 1
+ (ππβ β
ππ ) (ππ β
ππ )
πβπ·
β
2π΄ 2 π 2ππβπ·π β πππ]πΌπ½ ππβπ ππ] πππΌ πππ½ }, ππ + ππ·π ππ + ππ·π
A (π σ³¨β π·πβ πΎβ+ ) = βπ
πΊπΉ β2 πβπ·π
β β ππ’π π1 {(ππΎ β
ππΎβ ππΎβ πππ β β
ππ ) (ππ + ππ· ) π΄ 1 π
β + (ππΎ β β
ππ ) (ππ β
ππΎβ )
0
A (π σ³¨β π·π’ πΎ ) = β2πΊπΉ ππ (ππ β
ππΎ ) β
ππΎ π΄ 0
β + (ππΎ β β
ππ ) (ππ β
ππΎβ )
βπ
πΌ π½ β πππ]πΌπ½ ππΎβ ππ] ππΎ β ππ
πβπ·
2π΄ 2 π ππ + ππ·π
2ππβπ·π }, ππ + ππ·π
Advances in High Energy Physics 0
A (π σ³¨β π·π’ π0 ) = +π
πβπ·π’
β
ππ + ππ·π’ 0
=π
+ (ππβ β
ππ ) (ππ β
ππ )
β πππ]πΌπ½ ππβπ ππ] πππΌ πππ½
A (π σ³¨β π·π’ π) = βπ
A (ππ σ³¨β π·π β πΎ+ )
πΊπΉ π π πβ π π {(ππβ β
ππ ) 2 π π ππ π’π 2
β
(ππ + ππ·π’ ) π΄ 1 πβπ· 2π΄ 2 π’
9
A (ππ σ³¨β π·πβ π+ )
πβπ·π’
2π }, ππ + ππ·π’
=π
πΊπΉ π π πβ π π {(ππβ β
ππ ) 2 π π ππ π’π 2
πβπ·π’
β
(ππ + ππ·π’ ) π΄ 1
=π
+ (ππβ β
ππ ) (ππ β
ππ )
πβπ·
A (π σ³¨β
πβπ·π’
0
= βπ
0
+ (ππβ β
ππ ) (ππ β
ππ )
=π
2π΄ 2 π’ 2ππβπ·π’ βπ β πππ]πΌπ½ ππ ππ] πππΌ πππ½ }, ππ + ππ·π’ ππ + ππ·π’ 0
A (π σ³¨β π·π’ πΎβ0 ) = βπ
0
πΊπΉ β2
=π
πβπ·
βπ
=π
0
β0
0
2π }, ππ + ππ·π’
=π
πΊπΉ β2
0
0
= cos πA (ππ σ³¨β π·π’ ππ )
πβπ·π’
0
β sin πA (ππ σ³¨β π·π’ ππ ) ,
πβπ·
2π΄ 2 π’ β
ππ ) (ππ β
ππΎβ ) ππ + ππ·π’ βπ
πΌ π½ β πππ]πΌπ½ ππΎβ ππ] ππΎ β ππ
πΊπΉ π βπ· 2 (ππ2π β ππ· ) πππ πΉ0 π π’ ππ’π πππ β π2 , π’ β2
A (ππ σ³¨β π·π’ π)
β β
ππΎβ ππΎβ πππ β ππ’π π2 {(ππΎ β β
ππ ) (ππ + ππ· ) π΄ 1 π’
β + (ππΎ β
πΊπΉ π βπ· 2 β ) πππ πΉ0 π π’ ππ’π πππ π2 , (ππ2π β ππ· π’ 2
A (ππ σ³¨β π·π’ ππ )
πβπ·π’
A (π σ³¨β π·π’ πΎ ) = βπ
πΊπΉ π βπ· 2 (ππ2π β ππ· ) ππΎ πΉ0 π π’ ππ’π πππ β π2 , π’ β2
A (ππ σ³¨β π·π’ ππ )
2π΄ 2 π’ β
ππ ) (ππ β
ππΎβ ) ππ + ππ·π’
πΌ π½ β πππ]πΌπ½ ππΎβ ππ] ππΎ β ππ
0
0
πβπ·π’
+
πΊπΉ π βπ· 2 β (ππ2π β ππ· ) ππΎ πΉ0 π π’ ππ’π πππ π2 , π’ β2
A (ππ σ³¨β π·π’ πΎ )
β β β
ππΎβ ππΎβ πππ ππ’π π2 {(ππΎ β β
ππ ) (ππ + ππ· ) π΄ 1 π’
β (ππΎ β
πΊπΉ π βπ· 2 β ) ππ πΉ0 π π’ ππ’π πππ π2 , (ππ2π β ππ· π’ 2
A (ππ σ³¨β π·π’ πΎ0 )
πβπ·
β
πΊπΉ π βπ· 2 β (ππ2π β ππ· ) ππΎ πΉ0 π π ππ’π πππ π1 , π β2
A (ππ σ³¨β π·π’ π0 )
πΊ = βπ πΉ ππ ππ πππ β ππ’π π2 {(ππβ β
ππ ) β2
β
(ππ + ππ·π’ ) π΄ 1
πΊπΉ π βπ· 2 β (ππ2π β ππ· ) ππ πΉ0 π π ππ’π πππ π1 , π β2
A (ππ σ³¨β π·πβ πΎ+ )
2π΄ 2 π’ 2ππβπ·π’ β
β πππ]πΌπ½ ππβπ ππ] πππΌ πππ½ }, ππ + ππ·π’ ππ + ππ·π’ 0 π·π’ π)
πΊπΉ π βπ· 2 (ππ2π β ππ· ) ππΎ πΉ0 π π ππ’π πππ β π1 , π β2
0
A (ππ σ³¨β π·π’ πσΈ )
2ππβπ·π’ }. ππ + ππ·π’
0
= sin πA (ππ σ³¨β π·π’ ππ ) (A.1)
B. The Amplitudes for the ππ β π·π Decays
0
+ cos πA (ππ σ³¨β π·π’ ππ ) , A (ππ σ³¨β π·π β π+ ) π βπ·π
Consider A (ππ σ³¨β π·π β π+ ) =π
πΊπΉ π βπ· 2 (ππ2π β ππ· ) ππ πΉ0 π π ππ’π πππ β π1 , π β2
= β2πΊπΉ ππ (ππβ β
πππ ) ππ πΉ1 π
ππ’π πππ β π1 ,
A (ππ σ³¨β π·π β πΎβ+ ) π βπ·π
β π = β2πΊπΉ ππΎβ (ππΎ β β
ππ ) ππΎβ πΉ 1 π
ππ’π πππ β π1 ,
10
Advances in High Energy Physics A (ππ σ³¨β π·πβ π+ ) π βπ·π
= β2πΊπΉ ππ (ππβ β
πππ ) ππ πΉ1 π
β ππ’π πππ π1 ,
A (ππ σ³¨β π·πβ πΎβ+ ) π βπ·π
β π = β2πΊπΉ ππΎβ (ππΎ β β
ππ ) ππΎβ πΉ 1 π
β ππ’π πππ π1 ,
0
A (ππ σ³¨β π·π’ π0 ) π βπ·π’
= βπΊπΉ ππ (ππβ β
πππ ) ππ πΉ1 π
β ππ’π πππ π2 ,
0
A (ππ σ³¨β π·π’ π) π βπ·π’
= πΊπΉ ππ (ππβ β
πππ ) ππ πΉ1 π
β ππ’π πππ π2 ,
0
A (ππ σ³¨β π·π’ π) π βπ·π’
= β2πΊπΉ ππ (ππβ β
πππ ) ππ πΉ1 π
ππ’π πππ β π2 ,
0
A (ππ σ³¨β π·π’ πΎβ0 ) π βπ·π’
β ππ’π πππ π2 ,
π βπ·π’
ππ’π πππ β π2 .
β π = β2πΊπΉ ππΎβ (ππΎ β β
ππ ) ππΎβ πΉ 1 π 0
β0
A (ππ σ³¨β π·π’ πΎ ) β π = β2πΊπΉ ππΎβ (ππΎ β β
ππ ) ππΎβ πΉ 1 π
(B.1)
Conflict of Interests The authors declare that there is no conflict of interests regarding the publication of this paper.
Acknowledgment The work is supported by the National Natural Science Foundation of China (Grants nos. 11547014, 11275057, 11475055, U1232101, and U1332103).
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