Analysis of angular observables of Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) decay in the standard and Z ' models
文献类型:期刊论文
作者 | Nasrullah, A; Aslam, MJ; Shafaq, S |
刊名 | PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
![]() |
出版日期 | 2018 |
期号 | 4页码:043B08 |
ISSN号 | 2050-3911 |
DOI | 10.1093/ptep/pty043 |
文献子类 | Article |
英文摘要 | In 2015, the LHCb collaboration measured the differential branching ratio dB/dq(2), the lepton- and hadron-side forward-backward asymmetries, denoted by A(FB)(l) and A(FB)(Lambda), respectively, in the range 15 < q(2)(= s) < 20 GeV2 with 3 fb(-1) of data. Motivated by these measurements, we perform an analysis of q(2)-dependent Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) angular observables at large-and low-recoil in the standard model ( SM) and in a family non-universal Z' model. The exclusive Lambda(b) -> Lambda transition is governed by the form factors, and in the present study we use the recently performed high-precision lattice QCD calculations that have well-controlled uncertainties, especially in the 15 < s < 20 GeV2 bin. Using the full four-folded angular distribution of Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) decay, first of all we focus on calculations of the experimentally measured dB/ds, A(FB)(l), and AFB(Lambda) in the SM and compare their numerical values with the measurements in appropriate bins of s. In case of a possible discrepancy between the SM prediction and the measurements, we try to see if these can be accommodated though the extra neutral Z' boson. We find that in the dimuon momentum range 15 < s < 20 GeV2 the value of dB/ds and central value of AFB(l) in the Z' model is compatible with the measured values. In addition, the fraction of longitudinal polarization of the dimuon F-L was measured to be 0.61(-0.14)(-0.11) +/- 0.03 in 15 < s < 20 GeV2 at the LHCb. We find that in this bin the value found in the Z' model is close to the observed values. After comparing the results of these observables, we have proposed other observables such as alpha(i) and alpha(('))(i) with i = theta(l), theta(Lambda), phi, L, U and coefficients of different foldings P-1,P-...,P-9 in different bins of s in the SM and Z' model. We illustrate that the experimental observations of the s-dependent angular observables calculated here in several bins of s can help to test the predictions of the SM and unravel new physics contributions arising due to the Z' model in Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) decays. |
WOS关键词 | CHANGING NEUTRAL CURRENTS ; DOUBLE-LEPTON POLARIZATION ; LAMBDA-L(+)L(-) DECAY ; B-S ; PENGUIN DECAYS ; LEPTOPHOBIC Z' ; HEAVY BARYONS ; K DECAYS ; FLAVOR ; CONSTRAINTS |
WOS研究方向 | Physics |
语种 | 英语 |
WOS记录号 | WOS:000431146800002 |
源URL | [http://ir.ihep.ac.cn/handle/311005/287023] ![]() |
专题 | 高能物理研究所_理论物理室 |
通讯作者 | Aslam, MJ |
作者单位 | 中国科学院高能物理研究所 |
推荐引用方式 GB/T 7714 | Nasrullah, A,Aslam, MJ,Shafaq, S. Analysis of angular observables of Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) decay in the standard and Z ' models[J]. PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS,2018(4):043B08. |
APA | Nasrullah, A,Aslam, MJ,&Shafaq, S.(2018).Analysis of angular observables of Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) decay in the standard and Z ' models.PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS(4),043B08. |
MLA | Nasrullah, A,et al."Analysis of angular observables of Lambda(b) -> Lambda (-> p pi) mu(+)mu(-) decay in the standard and Z ' models".PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS .4(2018):043B08. |
入库方式: OAI收割
来源:高能物理研究所
浏览0
下载0
收藏0
其他版本
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。