Test of quantum nonlocality via vector meson decays to KSKS Pei-Cheng Jiang Xuan Wangand Da-Yong Wang School of Physics and State Key Laboratory of Nuclear Physics and Technology

2025-05-02 0 0 387.21KB 7 页 10玖币

侵权投诉

Test of quantum nonlocality via vector meson decays to KSKS

Pei-Cheng Jiang∗*, Xuan Wang†*and Da-Yong Wang‡*

*School of Physics and State Key Laboratory of Nuclear Physics and Technology

Peking University, Beijing 100871, China

Abstract

In the system of a pair of quantum-entangled neutral kaons from meson decays, when

one kaon collapses into the KSstate, the other will collapse instantaneously into the

KLstate due to entanglement and nonlocality. However, if the alternative hypothesis is

correct and there’s a time window during which one kaon is unaware that the other has

decayed, some quantum mechanically prohibited KSKSdecays may occur. We calculate

the branching ratios of KSKSin vector meson decays under the locality hypothesis and

compare them with experimental results. We show that the branching ratio of J/ψ →

KSKSunder locality assumption is already excluded by the BESIII experimental upper

limit. Additional experimental results are proposed to perform this test in the future.

1 Introduction

In 1935, Einstein, Podolsky, and Rosen (EPR) posed the question of whether or not quantum

mechanics oﬀers a complete description of reality [1]. They assumed the locality principle,

which states that interference eﬀects should travel at the speed of light or slower between two

objects. While in quantum mechanics, the measurement of one particle in an entangled system

has an instantaneous eﬀect on the other due to explicit nonlocality. Quantum-mechanics

nonlocality tests have been extensively carried out in optics and atomic physics studies [2–4].

All of the results are consistent with quantum mechanical predictions. High-energy physics

measurements may also reveal the incompatibility of quantum physics with local realism [5].

Noninstantaneous interaction in the neutral kaon system is sensitive to testing the nonlo-

cality of quantum mechanics. Under Einstein’s assumption of locality, the neutral kaon system

must produce some KSKSdecays in the space-like region, despite the fact that quantum me-

chanics prohibits this process [6].

In this paper, we calculate the branching ratios of vector meson decays to KSKSunder the

locality assumption and compare them with experimental results in order to test for nonlocal

phenomena in neutral kaon systems. Additional experimental measurements of such channels

are proposed to perform this test in the future.

2 Entangled neutral kaons system

We discuss the test in the reaction

V→K0¯

K0,(1)

where V is a vector meson (φ,J/ψ, Υ...) with quantum numbers JP C = 1−−. For the

entangled system of two neutral kaons, immediately after the decay (at time zero), the quan-

tum–mechanical state could be depicted as

∗jiangpc@stu.pku.edu.cn

†wangxuan15@pku.edu.cn

‡dayong.wang@pku.edu.cn

arXiv:2210.04125v2 [hep-ph] 7 Nov 2022

|φ(0)i=1

√2

K0a

¯

K0b−

¯

K0a

K0b

√2{|KSia|KLib− |KLia|KSib},

(2)

where aand bdenote the two kaons’ opposing directions of motion. When the eﬀect of

CP violation is ignored, the CP eigenstates are identical to KSand KL, which are short-lived

and long-lived neutral kaons, respectively. Thus there is no KSKScomponent in the decay

products.

The time evolution of states KSand KLis given by

|KS(t)i=|KSiexp (−αst),|KL(t)i=|KLiexp (−αLt) (3)

respectively, where tis the particle proper time and

αs=1

2Γs+ims, αL=1

2ΓL+imL.(4)

In Eq. (4), ΓS(ΓL) and mS(mL) are the decay rates and masses for KS(KL), respectively.

According to quantum mechanics, the decay amplitude of the two kaons’ states into ﬁnal states

faand fbat proper times taand tbcan be written as [7]:

A(fa, ta;fb, tb) = 1

√2[hfa|T|KS(ta)ihfb|T|KL(tb)i

− hfa|T|KL(ta)ihfb|T|KS(tb)i]

√2[hfa|T|KSihfb|T|KLie−iαStae−iαLtb

− hfa|T|KLihfb|T|KSie−iαLtae−iαStb],

(5)

where Tis the transition operator from the two kaons’ states to the ﬁnal states.

Up to the moment of the ﬁrst kaon decay, the two kaons are entangled and the decay rate

for K0¯

K0→anything can be computed from equation (5), using the deﬁnition of (3) and (4):

Γent (ta, tb) =NΣfa,fb|A(fa, ta;fb, tb)|2

2ΓLΓS{e−ΓSta−ΓLtb+e−ΓStb−ΓLta

−2 cos [∆ (tb−ta)] e−1

2(tb+ta)(ΓS+ΓL)},

(6)

where ∆ = mL−mSand normalization factor N ≈1 + 2 (ΓL/ΓS)≈1.0035 guarantees the

integral of Γent to be 1.

After the decay of the ﬁrst kaon, the quantum interference between the two kaons disap-

pears and the decay rate becomes

Γnon ent (ta, tb) = 1

2ΓLΓSe−ΓSta−ΓLtb+e−ΓStb−ΓLta.(7)

The decay rate at time taof kaon acan be expressed as

Γa(ta) = Zta

dtbΓnon ent (ta, tb) + Z+∞

dtbΓent (ta, tb).(8)

Similarly, the decay rate at time tbof kaon bis given by Eq. (8) with the replacement

a↔b.

Combining the contributions of kaon aand kaon b, the decay rate of the ﬁrst decay at

time t1is

Γ1(t1)=2Z+∞

dt2Γent (t1, t2),(9)

文档加载中……请稍候！
如果长时间未打开，您也可以点击刷新试试。

下载文档到电脑，查找使用更方便

10 玖币 0人已下载

立即下载

摘要：

TestofquantumnonlocalityviavectormesondecaystoKSKSPei-ChengJiang**,XuanWang*andDa-YongWang**SchoolofPhysicsandStateKeyLaboratoryofNuclearPhysicsandTechnologyPekingUniversity,Beijing100871,ChinaAbstractInthesystemofapairofquantum-entangledneutralkaonsfrommesondecays,whenonekaoncollapsesintotheKSsta...

展开>> 收起<<

Test of quantum nonlocality via vector meson decays to KSKS Pei-Cheng Jiang Xuan Wangand Da-Yong Wang School of Physics and State Key Laboratory of Nuclear Physics and Technology.pdf

共7页,预览2页

还剩页未读，继续阅读

声明：本站为文档C2C交易模式，即用户上传的文档直接被用户下载，本站只是中间服务平台，本站所有文档下载所得的收益归上传人(含作者)所有。玖贝云文库仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对上载内容本身不做任何修改或编辑。若文档所含内容侵犯了您的版权或隐私，请立即通知玖贝云文库，我们立即给予删除！

Test of quantum nonlocality via vector meson decays to KSKS Pei-Cheng Jiang Xuan Wangand Da-Yong Wang School of Physics and State Key Laboratory of Nuclear Physics and Technology

相关推荐

开通VIP享超值会员特权

作者详情

相关内容

热门标签

举报选择: