S波重夸克族的超前扭曲parton分布幅度资源-CSDN文库

Open

Access

91 浏览量 2020-04-04 08:36:33 上传评论收藏 440KB PDF 举报

资源推荐

资源详情

资源评论

Physics Letters B 753 (2016) 330–335

Contents lists available at ScienceDirect

Physics Letters B

www.elsevier.com/locate/physletb

Leading-twist parton distribution amplitudes of S-wave

heavy-quarkonia

Minghui Ding

a,b

, Fei Gao

a,b

, Lei Chang

, Yu-Xin Liu

a,b,d,∗

, Craig D. Roberts

e,∗

Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China

Collaborative Innovation Center of Quantum Matter, Beijing 100871, China

School of Physics, Nankai University, Tianjin 300071, China

Center for High Energy Physics, Peking University, Beijing 100871, China

Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA

a r t i c l e i n f o a b s t r a c t

Article history:

Received

17 November 2015

Accepted

30 November 2015

Available

online 8 December 2015

Editor:

A. Ringwald

Keywords:

Heavy

quarkonia

Hard

exclusive processes

Parton

distribution amplitudes

Dyson–Schwinger

equations

Conﬁnement

Non-relativistic

quantum chromodynamics

The leading-twist parton distribution amplitudes (PDAs) of ground-state

and

c-and b

quarkonia

are calculated using a symmetry-preserving continuum treatment of the meson bound-state

problem which uniﬁes the properties of these heavy-quark systems with those of light-quark bound-

states,

including QCD’s Goldstone modes. Analysing the evolution of

and

PDAs with current-quark

mass,

, increasing away from the chiral limit, it is found that in all cases there is a value of

for which the PDA matches the asymptotic form appropriate to QCD’s conformal limit and hence is

insensitive to changes in renormalisation scale, ζ . This mass lies just above that associated with the

s-quark. At current-quark masses associated with heavy-quarkonia, on the other hand, the PDAs are

piecewise convex–concave–convex. They are much narrower than the asymptotic distribution on a large

domain of ζ ; but nonetheless deviate noticeably from ϕ

(x) = δ(x − 1/2), which is the result in the

static-quark limit. There are also material differences between

and

PDAs, and between the PDAs

for different vector-meson polarisations, which vanish slowly with increasing ζ . An analysis of moments

of the root-mean-square relative-velocity, v

, in

and

systems reveals that v

-contributions

may be needed in order to obtain a reliable estimate of matrix elements using such an expansion,

especially for processes involving heavy pseudoscalar quarkonia.

Elsevier B.V. This is an open access article under the CC BY license

(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP

1. Introduction

In studying hard exclusive processes within the Standard Model

there are many instances in which one may appeal to factorisa-

tion

theorems so that, at leading-order in a systematic expansion,

the amplitude involved can be written as a convolution of a hard-

scattering

kernel, calculable in perturbation theory, and the so-

called

leading-twist PDA of the hadron involved, ϕ(x), where x is

the light-front fraction of the hadron’s total momentum carried by

the struck parton. Well known examples are formulae for the large

momentum-transfer (asymptotic) behaviour of the electromagnetic

charged-pion elastic and neutral-pion transition form factors [1–4].

For

mesons, the PDA is a light-front projection of the system’s

Bethe–Salpeter wave-function onto the light-front. It is therefore

process independent and hence plays a crucial role in explaining

Corresponding authors.

E-mail

addresses: yxliu@pku.edu.cn (Y.-X. Liu), cdroberts@anl.gov (C.D. Roberts).

and understanding a wide range of a given meson’s properties and

interactions. The PDA is also essentially nonperturbative, i.e. it can-

not

be calculated using perturbation theory. The last two decades

have witnessed signiﬁcant progress toward the computation of re-

alistic

meson Bethe–Salpeter amplitudes [5–8]; and, critically, the

last two years have seen the development of novel techniques

which enable the reliable calculation of meson PDAs from such

Bethe–Salpeter amplitudes [9,10]. Predictions are now available for

the (leading) twist-two PDAs of the π -, K -, ρ- and φ-mesons

[11–13], and for twist-three pion and kaon PDAs [14,15].

Given

that the last ﬁfteen years have seen a dramatic expan-

sion

of interest in heavy-quark systems, owing to advances in both

theoretical methods, and experimental activity and discoveries [16,

17],

it is an opportune moment to use the continuum approach in-

dicated

above in order to compute the twist-two PDAs of S-wave

heavy-quarkonia. The theoretical interest is plain: one thereby ar-

rives

at a uniﬁed description and explanation of the leading-twist

PDAs for almost all empirically accessible pseudoscalar and vec-

tor

mesons. This means, e.g. that one simultaneously obtains an

http://dx.doi.org/10.1016/j.physletb.2015.11.075

0370-2693/

BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP

本内容试读结束，登录后可阅读更多

下载后可阅读完整内容，剩余5页未读，立即下载

评论收藏

内容反馈

weixin_38678057

粉丝: 6
资源: 870

S波重夸克族的超前扭曲parton分布幅度

S波和P波B c介子的超前扭曲光锥分布幅度

D-介子超前扭曲分布幅度引起的B→D过渡形状因子的不确定性

QCD理论中背景场中的重伪标量超前扭曲分布幅度

对S波B c介子和重夸克族的光锥分布幅度的相对论校正

风味对称性破坏了kaon parton分布幅度

光子-夸克异常耦合引起的Parton分布和cos2ϕh不对称

关于Pretzelosity TMD parton分布的注释

完全协变成分夸克模型中的Pion广义parton分布

介子价夸克parton分布函数

关联各种parton分布的横向结构

绘制介子的价夸克广义parton分布示意图

S波重夸克尼亚的独家电生产中的理论不确定性

通过Wilson线重归一化改善准Parton分布

格子上Parton拟分布函数的非局部夸克双线性非扰动重整化

重夸克族与等矢量四夸克态之间的辐射跃迁和ρ跃迁

重夸克对称性导致重双重子的简并性

强子量子涨落的核子parton分布

通过独家制造具有大不变质量的γπ±对来探测轴向夸克广义parton分布

电磁对parton分布中电荷对称性违反的贡献

光前模型中的扭曲三分布（，）

基于格QCD的Pion广义parton分布

用高扭曲方法重新研究核中夸克的辐射能损失

LHCb实验测得的重口味产品横截面对低x时parton分布函数的影响

夸克横向自旋轨道的相关性

Spin-1目标的广义parton分布的多项式和规则

恢复夸克对生产中的速度分布

具有指数型约束势的光前夸克模型中Twist-2伪标量和矢量介子分布幅度

最新资源