On the neutron-antineutron oscillations
L. B. Okun
这是我在2013年3月应Chris Quigg的要求为X项目撰写的关于$n\bar{n}$振荡早期历史的简要说明的草稿。
This is a draft of my brief note on the early history of $n\bar{n}$ oscillations written for the Project X at the request of Chris Quigg in March 2013.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
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An observation of neutron-antineutron oscillations ($ n-\bar{n}$), which violate both $B$ and $B-L$ conservation, would constitute a scientific discovery of fundamental importance to physics and cosmology. A stringent upper bound on its transition rate would make an important contribution to our understanding of the baryon asymmetry of the universe by eliminating the post-sphaleron baryogenesis scenario in the light quark sector. We show that one can design an experiment using slow neutrons that in principle can reach the required sensitivity of $τ_{n-\bar{n}}\sim 10^{10}s$ in the oscillation …
We summarize the current status of baryon number violation in supersymmetry and provide prospects for going beyond the present reach by means of a new search for neutron-antineutron oscillations. The main motivation is the recently proposed neutron-antineutron oscillation experiment at the European Spallation Source in Lund, Sweden, which is projected to be able to improve the current bound on the transition probability in the quasi-free regime by three orders of magnitude. We consider various processes involving superpartners that give rise to neutron-antineutron oscillations and extract the …
Coupling Unification, GUT-Scale Baryogenesis and Neutron-Antineutron Oscillation in SO(10)
我们证明了，如果色六重态标量场在TeV尺度下仍然存在，那么在一类一步破缺到标准模型的非超对称SO（10）模型中，三个规范场耦合的统一可以一致地实现.这样的标量，应该可以被LHC直接探测到，在SO（10）中自然产生，作为中微子质量的跷跷板机制的残余。这些标量的双夸克耦合导致了ΔB = 2重子数的破坏过程，如中子-反中子振荡。我们估计自由中子-反中子跃迁时间为τ_{n- \bar{n} } \approx（10 ^9 -10^{12}）秒，其在下一代n- \bar{n}振荡实验的感兴趣的范围内。这些模型也自然地实现了最近提出的（B-L）-违反GUT标度重子发生，生存到低温不受电弱sphaleron相互作用。
The values of the antineutron-nucleus scattering lengths, and in particular their imaginary parts, are needed to evaluate the feasibility of using neutron mirrors in laboratory experiments to search for neutron-antineutron oscillations. We analyze existing experimental and theoretical constraints on these values with emphasis on low $A$ nuclei and use the results to suggest materials for the neutron/antineutron guide and to evaluate the systematic uncertainties in estimating the neutron-antineutron oscillation time. As an example we discuss a scenario for a future neutron-antineutron oscillati…
Reason of Large Scale Difference of the Results in the Neutron- antineutron Oscillation Problem
我们揭示了介质中中子-反中子跃迁的标准模型中隐藏的一个严重缺陷。修正它，一个提高了31个数量级的自由空间中子反中子振荡时间的限制。
We study the systematic decomposition of the dimension nine neutron-antineutron oscillation operators at tree and one-loop levels. We discuss the topologies' generation and the assignment of the chiral quarks. The completed lists of the decompositions are provided. We furthermore show an example that the neutron-antineutron oscillation occurs at one-loop level, with the tiny neutrino mass being generated via the scotogenic model and proton decay being evaded.
A new high sensitivity search for neutron-antineutron oscillations at the ESS
对中子-反中子振荡的敏感研究可以为粒子物理学和宇宙学中的一些核心问题提供独特的探索：重子数破坏的能量尺度和机制，宇宙的重子-反重子不对称性的起源，以及中微子质量产生的机制。一个显着的机会已经出现了寻找这样的振荡与欧洲SpectrossSource（ESS）的建设。已经形成了一个合作，提出了一个搜索在ESS，这将提供一个灵敏度的振荡概率是三个数量级以上的ILL实验，在该实验中获得了目前最好的限制自由中子反中子振荡。
Transformation of neutron to antineutron is a small effect that has not yet been experimentally observed. %\cite{Phillips:2014fgb}. In principle, it can occur with free neutrons in the vacuum or with bound neutrons inside the nuclear environment different for neutrons and antineutrons and for that reason in the latter case it is heavily suppressed. Free neutron transformation also can be suppressed if environmental vector field exists destinguishing neutron from antineutron. We consider here the case of a vector field coupled to $B-L$ charge of the particles ($B-L$ photons) and study a possibi…
We construct the Chiral Perturbation Theory operators for neutron-antineutron oscillations and use these to estimate chiral and finite volume corrections at one-loop order.
Neutron-Antineutron transitions from exotic instantons: how fast they might be and further implications
讨论了开弦论在B-破坏低能物理中的应用。特别地，奇异瞬子可以动态地产生有效的六夸克算符，导致中子-反中子跃迁。质子不稳定，并且风味改变中性电流在控制之下。
Neutron-antineutron transition as a test-bed for dynamical CPT violations
我们显示了一个简单的机制，在中子部门的动态CPT违反。特别是，我们显示了{\it CPT违反跷跷板机制}，产生马约拉纳质量和CPT违反质量的中子。违反CPT的跷跷板涉及中子的无菌伙伴，生活在一个隐藏的部门，其中CPT自发破裂。特别是，中子（反中子）可以通过称为{\it奇异瞬子}的非微扰量子引力效应与隐藏扇区通信。奇异瞬子动态地打破R宇称，在中子和它的不育伙伴之间产生一个有效顶点。通过这种方式，我们展示了一个小CPT违反中子的质量项是如何自然产生的。这个模型可以在下一代的中子-反中子物理实验中得到检验。这强烈地激发了在中子-反中子物理中CPT破坏效应的研究，作为SM中动态CPT破坏的实验平台。
Neutron-Antineutron Oscillation as a Signal of CP Violation
假设洛伦兹和CPT不变性，我们表明，中子反中子振荡意味着打破CP随着重子数破坏-即两个萨哈罗夫条件的重子生成。振荡是由有效哈密顿量中的唯一算子产生的。这个混合了中子和反中子的算符保留了电荷共轭C，并破坏了P和T。外部磁场总是导致振荡抑制。它的存在不会导致任何新的算子混合中子和反中子。
Effects of Neutron-Antineutron Transitions in Neutron Stars
本文分析中子星内中子-反中子跃迁对冷却、自转速率和双星脉冲星轨道周期的影响，发现这些效应均可忽略。
We consider the possibility of neutron-antineutron ($n-\bar n$) conversion, in which the change of a neutron into an antineutron is mediated by an external source, as can occur in a scattering process. We develop the connections between $n-{\bar n}$ conversion and $n-{\bar n}$ oscillation, in which a neutron spontaneously tranforms into an antineutron, noting that if $n-{\bar n}$ oscillation occurs in a theory with B-L violation, then $n-{\bar n}$ conversion can occur also. We show how an experimental limit on $n-{\bar n}$ conversion could connect concretely to a limit on $n-{\bar n}$ oscillat…
Coherent forward neutron propagation in gas is discussed as a new approach to search for neutron-antineutron oscillations ($ n-\bar{n}$), which violate both $B$ and $B-L$ conservation. We show that one can increase the probability of neutron - antineutron transitions to essentially the free neutron oscillation rate in the presence of a nonzero external magnetic field by tuning the density of an appropriate mixture of gases so that the neutron optical potential of the gas cancels that from an external magnetic field.
The scotogenic mechanism for radiative neutrino mass is generalized to include neutron-antineutron oscillation as well as proton decay. Dark matter is stabilized by extending the notion of lepton parity to matter parity. Leptogenesis is also a possible byproduct. This framework unifies the description of all these important, but seemingly unrelated, topics in physics beyond the standard model of particle interactions.
Limiting Lorentz Violation from Neutron--Antineutron Oscillation
我们指出，如果在自由中子振荡实验中观察到中子-反中子振荡，就会将中子违反洛伦兹不变性（LIV）质量算符的强度上限限制在$10^{-23}$ GeV左右的水平上，这将是最严格的LIV限制。我们还研究了$ΔB=2$ LIV运营商的约束，并发现，对于一个特定的运营商消磁是没有必要获得可见的信号。我们还注意到，在核子衰变搜索实验中，由于中子和反中子之间的核电势差将掩盖任何洛伦兹破坏效应，因此在涉及核的核子衰变搜索实验中观察到的$n-\bar{n}$振荡信号不会导致对LIV算符的任何限制。
We propose a new scenario for predicting a one-loop neutron-antineutron oscillation at a testable level, meanwhile, realizing a thermal or inflationary baryogenesis at a very high scale. Besides the standard model content, this scenario involves two real singlet scalars with very heavy masses, two color-triplet and iso-singlet scalars at the TeV scale, as well as a Majorana singlet fermion for a dark matter candidate.
On the "Field-Theoretical Approach" to the Neutron-Antineutron Oscillations in Nuclei
本文认为，在正确处理跃迁振幅的分析性质，特别是原子核中$n - \bar n$跃迁的二阶极结构，某些文献中讨论的“红外发散”并不出现。借助于图解法的显式计算表明，与真空中的振荡相比，在氘核中以及在任意核中，中子-反中子振荡都受到强烈的抑制。
We propose a new approach based on the Lindblad and Bloch equations for the density matrix to the problem of a neutron into an antineutron conversion. We consider three strategies to search for conversion: experiments with trapped neutrons, oscillations in nuclei, and quasi-free propagation. We draw a distinction between $n\bar{n}$ oscillations in which the probability that a neutron transforms into an antineutron depends on time according to the sine-square law and the non-oscillatory overdamped $n\bar{n}$ conversion. We show that in all three cases decoherence due to the interaction with the…
Neutron-antineutron Oscillation and Baryonic Majoron: Low Scale Spontaneous Baryon Violation
讨论了重子数$B$在MeV量级甚至更小的低尺度下自发破缺的可能性，从而在实验可及的水平上诱发中子-反中子振荡.一种相关的戈德斯通粒子，重子强子，可以在原子核或致密核物质中的中子到反中子跃迁中产生可观察到的效应。通过将重子数推广到$B-L$对称性，重子-重子可以等同于轻子数自发破缺所伴随的普通重子，而由于重子发射等原因，重子-重子可以等同于无中微子的$2β$.我们还讨论了重子数可能由QCD自身通过六夸克凝聚自发破缺的假说.
Baryogenesis by R-parity violating top quark decays and neutron-antineutron oscillations
研究了R宇称破缺和低尺度引力作用下超对称模型中重子不对称性的产生。该模型允许长寿命甚至稳定的质子和可观察到的中子-反中子振荡。
Comment to "On the field-theoretical approach to the neutron-antineutron oscillations in nuclei"
我们简要概述了目前的状态的$n\bar{n}$过渡问题和分析最近的手稿弗拉基米尔Kopeliovich（arXiv：0912.5065）。
Realistic calculations of nuclear disappearance lifetimes induced by neutron-antineutron oscillations
现实的计算核消失寿命的中子-反中子振荡引起的氧和铁的报告，使用反中子核势来自最近的反质子原子X射线和放射化学数据的综合分析。中子-反中子振荡时间的下限为3.3 × 10 E8秒，这是从Super-Kamiokande I的氧中子寿命的新下限1.77 × 10 E32年推导出来的。在碳和镍中的反中子散射长度，需要在陷阱实验中使用超冷中子，计算更新的反核子光学势在阈值，结果显示在很大程度上是模型独立的。
Neutron-antineutron oscillation and parity and CP symmetries
结果表明，中子-反中子振荡本身并不一定意味着CP破坏在一个有效的本地洛伦兹不变描述的中子，保留CPT，相反，最近在文献中的分析。CP和重子数破坏项可以转化为CP守恒项，从而使CP破坏成为虚假的，例如在重子生成的分析中无法使用。它还表明，在一个$ΔB=2$，洛伦兹和CPT不变的相互作用的中子-反中子振荡可以发生只有当宇称被违反，无论CP属性;当宇称是保守的，它是普通的量子跃迁从中子到反中子发生。通过明确分析P、C和CP破坏或其守恒的所有可能组合，证明了这些陈述。此外，在本模型中，一个适当的组合的P=奇数和P=偶数$ΔB=2$的相互作用被证明会产生CP保持质量项的右手中微子，如果一个取代的中子的中微子，加强的结论。
We examine what role do collisions with the wall play in neutron-antineutron transitions. The collision time for $n$ and $\bar{n}$ and the phase difference between reflected $n$ and $\bar{n}$ waves are calculated. It is shown that transitions inside the wall are negligible.
Inflationary baryogenesis with low reheating temperature and testable neutron-antineutron oscillation
最近我们用四个TeV尺度的场（包括一个单重态费米子、一个等三重态和两个等单重态双夸克标量）扩展了标准模型，产生了具有可观测到的中子-反中子振荡的宇宙学重子不对称性.我们现在超对称化我们的模型，但不限制它在TeV尺度。单态费米子的超伴子可以作为暴胀子场。它的三体衰变，介导的等单重双夸克和他们的超伙伴，可以同时提供一个低的再加热温度和相当大的CP不对称性。因此，我们可以实现一个非热重子生成没有引力子的问题。同时，当等重态双夸克处于TeV量级时，一个等重态双夸克和两个等重态双夸克的交换可以产生可测的中子-反中子振荡。
SUPPRESSION OF THE NEUTRON-ANTINEUTRON OSCILLATION IN NUCLEI
本文在光势模型下，用场论S矩阵方法分析了由中子-反中子振荡引起的核衰变问题。在场论S-矩阵方法中重新推导了光学势模型的结果。原子核中的中子-反中子振荡被大大抑制.我们讨论了一个例子的自旋旋进的原子中，类似的抑制发生由于透明的物理原因。
Observable Neutron Antineutron Oscillation in High Scale Seesaw Models
讨论了一个基于规范群$SU(2)_L\times SU(2)_R\times SU(4)_c$的高尺度（$v_{BL}\sim 10^{12}$ GeV）超对称跷跷板模型，在该模型中中子-反中子振荡可以以可观测的速率发生.这与朴素的维数论证相反，该论证认为$τ_{N-\bar{N}}\propto v_{BL}^5$是不可观测的，如果跷跷板尺度为$v_{BL}\geq 10^{5}$ GeV。在我们的模型中，增强速率的两个原因是：（i）偶然的全局对称性，使一些双夸克希格斯质量保持在弱标度;（ii）来自低维算子的新的超对称贡献。最终结果是$τ_{N-\bar{N}}\propto v_{BL}^2 v^3_{wk}$而不是$v^5_{BL}$，导致增强。该模型也可以解释物质的起源通过leptogenesis，并在LHC中可以测试，轻双夸克态可以产生。
Degeneracy Enhancement of Neutron-Antineutron Oscillation in Neutron Star
本文提出简并环境中的费米子振荡会因泡利阻塞而产生方向性增强，并据此利用中子星加热对中子-反中子交叉质量项施加严格约束。
We analyze status of ${\bf C}$, ${\bf P}$ and ${\bf T}$ discrete symmetries in application to neutron-antineutron transitions breaking conservation of baryon charge ${\cal B}$ by two units. At the level of free particles all these symmetries are preserved. This includes ${\bf P}$ reflection in spite of the opposite internal parities usually ascribed to neutron and antineutron. Explanation, which goes back to the 1937 papers by E. Majorana and by G. Racah, is based on a definition of parity satisfying ${\bf P}^{2}=-1$, instead of ${\bf P}^{2}=1$, and ascribing $ {\bf P}=i$ to both, neutron and …
In the analysis of neutron-antineutron oscillations, it has been recently argued in the literature that the use of the $iγ^{0}$ parity $n^{p}(t,-\vec{x})=iγ^{0}n(t,-\vec{x})$ which is consistent with the Majorana condition is mandatory and that the ordinary parity transformation of the neutron field $n^{p}(t,-\vec{x}) = γ^{0}n(t,-\vec{x})$ has a difficulty. We show that a careful treatment of the ordinary parity transformation of the neutron works in the analysis of neutron-antineutron oscillations. Technically, the CP symmetry in the mass diagonalization procedure is important and the two par…
We study a simple TeV-scale model of baryon number violation which explains the observed proximity of the dark matter and baryon abundances. The model has constraints arising from both low and high-energy processes, and in particular, predicts a sizable rate for the neutron-antineutron ($n-\bar{n}$) oscillation at low energy and the monojet signal at the LHC. We find an interesting complementarity among the constraints arising from the observed baryon asymmetry, ratio of dark matter and baryon abundances, $n-\bar{n}$ oscillation lifetime and the LHC monojet signal. There are regions in the par…
Neutron--Antineutron Oscillations at the Surface of Nuclei
本文讨论了原子核中可能的中子-反中子振荡的某些方面。这种现象主要发生在原子核的表面，因此{ \sl i）}对介质修正不太敏感，{ \sl ii）}利用了欧洲核子研究中心实验探测的区域中的反核子-原子核相互作用。
Limits on the neutron-antineutron oscillation time from the stability of nuclei
我们驳斥了Nazaruk最近的一项主张，即对自由空间中子反中子振荡时间$τ_{n\bar n}$的限制相对于估计值$τ_{n\bar n}>2(T_0/Γ)^{1/2}$可以提高许多数量级，其中$T_0$是一个测量到的核湮灭寿命的限制，$Γ\sim 100$ MeV是一个典型的反中子核湮灭宽度。
We formulate the quantum field theory description of neutron-antineutron oscillations in the framework of canonical quantization, in analogy with the Bardeen--Cooper--Schrieffer (BCS) theory and the Nambu--Jona-Lasinio model. The physical vacuum of the theory is a condensate of pairs of {\it would-be neutrons and antineutrons} in the absence of the baryon-number violating interaction. The quantization procedure defines uniquely the mixing of massive Bogoliubov quasiparticle states which represent the neutron. In spite of not being mass eigenstates, neutron and antineutron states are defined on…
R-parity and baryon number violating operators can be allowed in the Supersymmetric Standard Model and thus lead to interesting baryon number violating processes such as neutron-antineutron oscillations and baryogenesis of the Universe via the decay of the lightest supersymmetric particle (LSP). Adopting the LSP baryogenesis mechanism realized by the late decay of the axino, we identify a single coupling lambda''_313 as a common origin for the matter-antimatter asymmetry of the Universe as well as potentially observable neutron-antineutron oscillation rates. From this, rather strong constraint…
Post-Sphaleron Baryogenesis and an Upper Limit on the Neutron-Antineutron Oscillation Time
本文讨论了最近提出的一种重子生成的方案，称为后球化子重子生成（PSB），它是在多TeV尺度下实现的基于规范对称性SU（2）_LxSU（2）_RxSU（4）_c的夸克-轻子统一框架下进行的.在这个模型中，宇宙的重子不对称性是在电弱相变温度以下，在球对称子与哈勃膨胀退耦之后产生的。这些模型嵌入自然的中微子质量的跷跷板机制，并预测色六重标量粒子在TeV范围内，这可能是访问的LHC实验。这种情况的必然结果是中子-反中子（n- \bar{n}）振荡的重子数破坏ΔB=2过程。在本文中，我们表明，PSB的限制，当结合中微子振荡数据和限制从味道改变中性电流介导的有色标量意味着上限的n- \bar{n}振荡时间为5 × 10^{10}秒。不管夸克-轻子统一尺度如何。如果该尺度相对较低，在（200-250）TeV范围内，τ_{n- \bar{n} }被预测为小于10^{10}秒，这对于下一代的实验来说是可行的。
On the critical examination of the "field-theoretical approach" to the neutron-antineutron oscillations in nuclei
本文简要介绍了原子核中$n\bar{n}$跃迁的模型，并分析了1992年发表的一个著名的基于图解技术的计算，该计算最近被V. Kopeliovich和I.钾
Neutron-antineutron transitions
我们确认了我们以前关于自由空间中子-反中子振荡时间t>4.7*10**31 y的极限。通过精确可解模型的实例验证了该方法的有效性。我们还讨论了所有现有的评论。有限时间区间的方法包括势模型作为一个极其简化的特殊情况。结果表明，势模型不适用于这个问题，因为对于反中子核衰变几率，势模型给出W=2。特别是，我们清楚地表明，这个“衰减定律”（归一化因子2）是由多佛，加尔和理查德用于反驳我们的结果。
On neutron-antineutron oscillation processes in solar cosmic-rays and the possibility of their observation
中子-反中子振荡的实验观测是基本粒子物理学中最古老的问题之一。然而，在地球上的实验室中对这些过程的研究迄今没有取得任何结果。本文考虑在耀斑增强时太阳宇宙射线中发现$n - \tilde n$振荡的可能性。有两个论点支持这种方法来解决这个问题：中子运行的距离很长，太阳宇宙射线环境中的磁场很弱。因此，太阳宇宙射线中反核子的存在可能是$n - \tilde n$振荡存在的一个证据。发现地球附近的$\tilde n$和$\tilde p$通量的预期强度。
Neutron-antineutron Oscillations in the Trapping Box
本文重新研究了阱中超冷中子的$n-\bar n$振荡问题。我们已经表明，$\bar n$分量随时间的增长是一个不错的精度由$P(\bar n)= ε^2_{n\bar n} t_Lt,$给出，其中$ε_{n\bar n}$是混合参数，$t_L\sim 1 $秒的中子传播时间之间的后续碰撞的陷阱壁。可能的更正，这部法律和开放的问题进行了讨论。
Baryogenesis and neutron-antineutron oscillation at TeV
我们提出了一个TeV的标准模型的扩展，以产生一个可观察到的中子-反中子振荡的宇宙学重子不对称性。新的场包括一个单重态费米子、一个等三重态和两个等单重态双夸克标量。虽然单重态费米子的马约拉纳质量以及一个等单重态双夸克和两个等三重态双夸克之间的三线性耦合会使重子数轻微地突破两个单位，但不会有质子衰变。等单线态双夸克耦合到两个右手下型夸克或一个右手上型夸克和一个单线态费米子，而等三线态双夸克耦合到两个左手夸克。等单重态双夸克介导了单重态费米子的三体衰变，实现了TeV的重子生成，而无需微调共振效应。通过一个单重态费米子和两个等单重态双夸克以及一个等单重态双夸克和两个等三重态双夸克的交换，可以在以后的实验中验证中子-反中子振荡。
Damping and Decoherence in Neutron Oscillations
分析了气体环境在中子-镜像中子和中子-反中子振荡中的作用。在第一个过程中，与周围介质的相互作用引起折射能移，其起到额外磁场的作用。在第二个过程中，反中子湮灭在实践中可能会导致强烈的退相干，这应该考虑到在实验中寻找中子到反中子的转换与自由中子。
Neutron-Antineutron Oscillations in a Warped Extra Dimension
我们研究了Randall-Sundrum扭曲的额外维度的情况下的中子-反中子振荡。计算了诱导振荡的相关算符的四维有效强度，以及由于QCD单圈运行效应引起的相应增强。我们发现，$ΔB = 2$运营商可以几何抑制没有微调到目前的实验范围内的翘曲下来的四维质量尺度，可以低至一个TeV的分数。
Fundamental symmetry tests of baryon number violation in low-energy experiments can probe beyond the Standard Model (BSM) explanations of the matter-antimatter asymmetry of the universe. Neutron-antineutron oscillations are predicted to be a signature of many baryogenesis mechanisms involving low-scale baryon number violation. This work presents first-principles calculations of neutron-antineutron matrix elements needed to accurately connect measurements of the neutron-antineutron oscillation rate to constraints on $|ΔB|=2$ baryon number violation in BSM theories. Several important systematic …
Dark-matter induced neutron-antineutron oscillations
本研究探讨携带2个重子数的轻暗物质诱导中子-反中子振荡的可能性，分析轴子实现方案后发现真实QCD轴子模型无法产生该效应，需普通标量或类轴子暗物质背景，且其对应实验特征值得探索。
Baryonic Axion in neutron-antineutron oscillation
研究轴子等暗物质候选者如何通过最一般耦合框架参与 $Δ\mathcal{B} = 2$ 的中子-反中子振荡，发现 ALPs 模型存在不受限的 Rabi 共振，而 QCD 轴子的 Goldstone 特性可排除大部分情景。
A Constraint to the Parity-Conserving Parameter of the Neutron-Antineutron Oscillations
将中微子振荡的唯象推广到大统一理论预言的中子-反中子振荡。一般有六个参数描述单味振荡：两个真正的马约拉纳质量（相反的符号），三个欧拉角，和一个相位乘数“chi”。马约拉纳质量之和作为一个小的宇称破坏参数“A”，诱导出核衰变（A，Z）->（A-2，Z），决定了真空中中子的振荡率。我们推导出一个小的宇称守恒参数“ε素”表示两个欧拉角的组合的约束。该参数对真空中的中子振荡率没有显著贡献，但对核衰变率有贡献。核稳定性意味着“epsilon-prime”< 1/年。真空中子振荡的不存在和核衰变的存在（A，Z）->（A-2，Z）将成为“epsilon-prime”=/ 0的最简单表现。
Observable Neutron-Antineutron Oscillations in Seesaw Models of Neutrino Mass
我们发现，在一个大类的超对称模型自发破缺的B-L对称，中子-反中子振荡发生在一个可观察的水平，即使B-L破缺的规模是非常高的，v_{B-L} ~ 2 × 10^{16} GeV，建议的规范耦合统一和中微子质量。我们说明了这种现象的上下文中最近提出的一类跷跷板模型，解决了强CP问题和超对称相位问题，使用奇偶对称。在这些模型中，我们得到了N- \bar{N}振荡时间的一个上限，τ_{N- \bar{N} } < 10^{9}-10 10}秒。这表明，如果将目前τ_{N- \bar{N} }的极限提高到0.86 × 10 ^8秒，那么，要么会导致N- \bar{N}振荡的发现，要么会大大限制一类有趣的中微子质量模型的允许参数空间。
We point out that if the baryon number violating neutron-antineutron oscillation is discovered, it would impose strong limits on the departure from Einstein's equivalence principle at a level of one part in $10^{19}$. If this departure owes its origin to the existence of long-range forces coupled to baryon number $B$ (or $B-L$), it would imply very stringent constraints on the strength of gauge bosons coupling to baryon number current. For instance, if the force mediating baryon number has strength $α_B$ and its range is larger than a megaparsec, we find the limit to be $α_B \leq 2\times 10^{-…
Neutron-antineutron ($n-\bar n$) oscillations in the deuteron are considered. Specifically, the deuteron lifetime is calculated in terms of the free-space $n-\bar n$ oscillation time $τ_{n-\bar n}$ based on $NN$ and $\bar NN$ interactions derived within chiral effective field theory (EFT). This results in $(2.6\pm 0.1) \times 10^{22}\,τ^2_{n-\bar n}$ s, which is close to the value obtained by Dover and collaborators more than three decades ago, but disagrees with recent EFT calculations that were performed within the perturbative scheme proposed by Kaplan, Savage, and Wise. Possible reasons fo…
In companion papers \cite{Addazi:2015pia,Addazi:2016rgo}, we have discussed current bounds of a new super-light baryo-photon, associated to a $U(1)_{B-L}$ gauged, from neutron-antineutron current data, which are competitive with Eötvös type experiments. Here, we discuss the implications of a possible baryo-photon detection in string theory and quantum gravity. The discovery of a very light gauge boson should imply the violation of the Weak Gravity Conjecture, carrying deep consequences in our understanding of holography, quantum gravity and black holes. On the other hand, we show how the detec…
Future neutron-antineutron ($n$-$\bar n$) oscillation experiments, such as at the European Spallation Source and the Deep Underground Neutrino Experiment, aim to find first evidence of baryon number violation. We investigate implications of an improved $n$-$\bar n$ oscillation search for baryogenesis via interactions of $n$-$\bar n$ mediators, parameterized by an effective field theory (EFT). We find that even in a minimal EFT setup, there is overlap between the parameter space probed by $n$-$\bar n$ oscillation and the region that can realize the observed baryon asymmetry of the universe. The…
With the imminent construction of the Deep Underground Neutrino Experiment (DUNE) and Hyper-Kamiokande, nucleon decay searches as a means to constrain beyond Standard Model (BSM) extensions are once again at the forefront of fundamental physics. Abundant neutrons within these large experimental volumes, along with future high-intensity neutron beams such as the European Spallation Source, offer a powerful, high-precision portal onto this physics through searches for $\mathcal{B}$ and $\mathcal{B}-\mathcal{L}$ violating processes such as neutron--antineutron transformations ($n\rightarrow\bar{n…
Critical Examination of the "Field-Theoretical Approach" to the Neutron-Antineutron Oscillations in Nuclei
我们证明，所谓的“红外发散”，已在一些出版物中讨论了几年，不出现在正确的处理的分析性质的过渡振幅，特别是，二阶极结构的振幅描述的$n - \bar n$过渡的核。显式计算的帮助下的Feynman图技术表明，中子-反中子振荡强烈抑制在氘核，以及在较重的核，在真空中的振荡相比。以宇称破坏的$np\to dγ$俘获振幅为例，指出了场论方法在核理论中应用的一般优点和某些困难。
Reason for the large scale differences in the results for the neutron-antineutron oscillation problem
结果表明，在介质中混合$n\bar {n}$的标准模型中存在重复计算，导致前导项完全抵消。直接计算了$n\bar{n}$跃迁后的湮没过程。自由空间$n\bar{n}$振荡时间的下限是$τ_{n\bar{n}} \sim T_{n\bar{n}}>10^{16}y$，其中$T_{n\bar{n}}$是束缚在核中的中子的寿命。这一限度超过了以前的16个数量级。
Supersymmetric $SU(2)_L\times SU(2)_R \times SU(4)_c$ and observable neutron-antineutron oscillation
我们证明了在一大类具有中微子质量的跷跷板机制和R宇称守恒真空的超对称$SU(2)_L\times SU(2)_R\times SU(4)_c$模型中，尽管$SU(2)_R\times SU(4)_c$对称性破缺的尺度在$10^{10}$ GeV附近，但仍存在质量接近弱尺度的双夸克希格斯玻色子（$M_{qq}$）.这是因为这些质量（$M_{qq}$）来自于稳定模型中电荷守恒真空所需的高维算符。这一特征有一个有趣的含义，即$ΔB=2$过程，如中子-反中子振荡，可以有可观测的速率，同时产生中微子质量在当前感兴趣的范围内。
Neutron-Antineutron Operator Renormalization
在质子衰变率被抑制的标准模型之外的重子数对称性破坏理论可以通过中子-反中子跃迁率的实验数据来约束。为了应用这个限制，在各种模型中的中子-反中子跃迁率的理论预测必须可用于比较。强子态之间跃迁速率的可靠预测必须包括非微扰量子色动力学效应。这些可以通过用晶格量子色动力学计算六夸克算符矩阵元以模型无关的方式计算。初步晶格计算已经进行，但运营商重整化效应必须包括为了匹配超出标准模型计算进行$\overline{MS}$重整化微扰理论与晶格正则化矩阵元素的结果。特别是，微扰计算的两个循环的异常尺寸和一个循环的重整化方案匹配系数，这些六夸克运营商是必要的，以确定领先的顺序在晶格匹配尺度的修正。这描述了我们正在进行的这些微扰算子重整化效应的计算。
Restriction on the Neutron-Antineutron Oscillations from the SNO Data on the Deuteron Stability
根据SNO关于氘稳定性的最新数据，$τ_D\,>\,3.01^.10^{31}$年，得到了真空中中子-反中子振荡时间的限制。在基于量子场论的图技术内进行的计算满意地再现了先前开发的势方法的结果。讨论了所得到的限制对湮灭$N\bar N$系统总自旋和氘核波函数修正的依赖性。
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