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arXiv 0705.4547hep-ph
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中性B介子系统存在大寿命差的可能性

Possibility of large lifetime differences in neutral B meson systems

Amol Dighe, Anirban Kundu, Soumitra Nandi

备注：
20 pages, 9 eps figures, revtex4 format
发表信息：
Phys.Rev.D76:054005,2007
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摘要：

我们调查新的物理模型，可以增加寿命差异的$B_q$ - $\bar{B}_q$系统（$q = d,s$）高于他们的标准模型值。如果$B_q$和$\bar{B}_q$都可以通过依赖于味道的新物理相互作用衰减到最终状态，则可以避开所谓的格罗斯曼界限。作为例子，我们考虑标量轻夸克模型和$λ''$型R宇称破缺超对称性。我们发现，具有标量细夸克的模型可以将$ΔΓ_s/Γ_s$一直增强到其实验上限，并将$ΔΓ_d/Γ_d$增强到与$\sim 2.5%$一样多，同时允许CP违反相$β_s$在$- 45^\circ$和$20^\circ$之间变化。R-宇称破坏超对称模型不能显著提高寿命差异，但可以提高$β_s$的值高达$\sim \pm 20^\circ$。这可能使$ΔΓ_q/Γ_q$和$β_s$的值在$B$工厂和LHCb的测量能力范围内。我们还得到这些新的物理耦合的组合上的界限，并预测增强分支比的$B_{s/d} \to τ^+ τ^-$。

英文摘要：

We investigate new physics models that can increase the lifetime differences in the $B_q$--$\bar{B}_q$ systems ($q = d,s$) above their standard model values. If both $B_q$ as well as $\bar{B}_q$ can decay to a final state through flavour dependent new physics interactions, the so-called Grossman bound may be evaded. As examples, we consider the scalar leptoquark model and $λ''$-type R-parity violating supersymmetry. We find that models with a scalar leptoquark can enhance $ΔΓ_s/Γ_s$ all the way up to its experimental upper bound and $ΔΓ_d/Γ_d$ to as much as $\sim 2.5%$, at the same time allowing the CP violating phase $β_s$ to vary between $- 45^\circ$ and $20^\circ$. R-parity violating supersymmetry models cannot enhance the lifetime differences significantly, but can enhance the value of $β_s$ up to $\sim \pm 20^\circ$. This may bring the values of $ΔΓ_q/Γ_q$ as well as $β_s$ within the measurement capabilities of $B$ factories and LHCb. We also obtain bounds on combinations of these new physics couplings, and predict enhanced branching ratios of $B_{s/d} \to τ^+ τ^-$.

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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