论文标题
大型强子对撞机的遥远中微子
Far-forward neutrinos at the Large Hadron Collider
论文作者
论文摘要
我们提出了从大型强子对撞机(LHC)产生的魅力和底部黑龙的衰减中高能中微子的能量分布的新计算。在非常远期速度的运动区域中,重量培养和衰减是tau中微子的来源,它导致成千上万的{带电电流} tau中微子事件在1 m长,1 m半径的铅中微子探测器的距离为480 m的距离为480 m的距离。在我们的计算中,在生产横截面中考虑了近代领先的QCD辐射校正。简单的现象学模型引入了Parton分布函数的高斯$ k_t $ - 令人震惊的简单现象学模型来近似非扰动的内在 - $ k_t $效应,这可能还会模仿由于多个初始状态软性luon的排放而导致的扰动效应。现象学碎片化函数描述了从党派到辐射状态的过渡。为了研究各种输入参数的效果,将$ d_s^\ pm $产生的理论预测与横向动量和速度的双分化横截面的LHCB数据进行了比较。讨论了与输入参数值选择有关的不确定性,最终会影响Tau Neutmino事件分布的预测。我们考虑一个3+1个中微子混合方案,以说明中微子实验使用Tau中微子和抗肿瘤限制3+1参数空间的潜力。我们在远方区域的中微子通量的预测中发现了较大的理论不确定性。将tau中微子振荡的影响解散为无菌中微子,并区分3+1场景与具有三种活性中微子口味的标准情况,由于QCD的理论不确定性很大,将具有挑战性。
We present a new calculation of the energy distribution of high-energy neutrinos from the decay of charm and bottom hadrons produced at the Large Hadron Collider (LHC). In the kinematical region of very forward rapidities, heavy-flavor production and decay is a source of tau neutrinos that leads to thousands of { charged-current} tau neutrino events in a 1 m long, 1 m radius lead neutrino detector at a distance of 480 m from the interaction region. In our computation, next-to-leading order QCD radiative corrections are accounted for in the production cross-sections. Non-perturbative intrinsic-$k_T$ effects are approximated by a simple phenomenological model introducing a Gaussian $k_T$-smearing of the parton distribution functions, which might also mimic perturbative effects due to multiple initial-state soft-gluon emissions. The transition from partonic to hadronic states is described by phenomenological fragmentation functions. To study the effect of various input parameters, theoretical predictions for $D_s^\pm$ production are compared with LHCb data on double-differential cross-sections in transverse momentum and rapidity. The uncertainties related to the choice of the input parameter values, ultimately affecting the predictions of the tau neutrino event distributions, are discussed. We consider a 3+1 neutrino mixing scenario to illustrate the potential for a neutrino experiment to constrain the 3+1 parameter space using tau neutrinos and antineutrinos. We find large theoretical uncertainties in the predictions of the neutrino fluxes in the far-forward region. Untangling the effects of tau neutrino oscillations into sterile neutrinos and distinguishing a 3+1 scenario from the standard scenario with three active neutrino flavours, will be challenging due to the large theoretical uncertainties from QCD.