Missing beauty of proton-proton interactions Iakov Aizenberg Alexander Milov Department of Physics and Astrophysics Weizmann Institute of Science

2025-05-02 0 0 1.24MB 6 页 10玖币

侵权投诉

Missing beauty of proton-proton interactions ∗

Iakov Aizenberg, Alexander Milov

Department of Physics and Astrophysics, Weizmann Institute of Science,

Rehovot, 761001, Israel

Zvi Citron

Department of Physics, Ben Gurion University of the Negev, Beer Sheva,

8410501, Israel

Received October 21, 2022

From ﬁrst principles, particles with the same quark content and sim-

ilar masses should have similar kinematic distributions. Transverse mass

scaling may be employed to estimate possible diﬀerences in the momentum

distribution of such particles. Based on this scaling the excited bottomo-

nium states measured at the LHC are found to be signiﬁcantly diﬀerent

from Υ(1S) to the extent that the integrated yield of Υ(2S) is 1.6 times

less and Υ(3S) 2.4 times less than would be explained by the mass diﬀer-

ence. This proceeding explains how the estimate is worked out and relates

it to other measurements performed at the LHC.

Recent measurements conducted by the ATLAS [1], CMS [2, 3] and

LHCb [4] experiments show that in proton-proton (pp) collisions the yield

of excited quarkonia states, (q¯q)?, with respect to the ground state, q¯q, di-

minishes with the event multiplicity. The magnitude of the eﬀect increases

at low transverse momentum (pT) of the particle. This eﬀect should have

an impact on the pTdistribution of the (q¯q)?which can be measured in

an independent analysis. An approach to do that can be based on the as-

sumption that particles with the same quark content and close mass should

have similar momentum distributions. This assumption is appropriate for

the Υ-meson family, in which the masses of the Υ(2S) and Υ(3S) are larger

than the mass of Υ(1S) by 6% 9.5%, respectively.

In a broader sense, this assumption is the basis of the transverse mass

(mT) scaling, stating that particles produced in pp collisions have the same

∗Presented at the XIVth International Conference on Beauty, Charm and Hyperon

Hadrons, June 5-11, 2022, Krak´ow, Poland by Alexander Milov

(1)

arXiv:2210.11026v1 [hep-ph] 20 Oct 2022

2mtproc printed on October 21, 2022

mT-distribution, where mT=qp2

T+m2and mis the particle rest mass.

The mT-scaling is widely exploited in many phenomenological studies [5–9]

and is often used in the form

dσ

dmT∝1 + mT

nT −n.(1)

The mT-scaling phenomenon is equivalent to the fact that the exponent n

and parameter Tare universal for all particles, although diﬀerent for mesons

and baryons (e.g. [8] and references therein). This analysis considers only

mesons. The scaling behavior of heavy mesons is studied in comparison to

light quark species and is used to understand the ratios between excited and

ground quarkonia states measured in experiments.

A comprehensive study of the mTdistributions of the mesons at three

LHC energies √s= 7,8, and 13 TeV is performed in [10]. It uses 72 data

samples of 18 mesons and their isospin partners. Figure 1 shows the param-

eter nobtained in ﬁts of individual data samples. When ﬁtting data with

0 2 4 6 8 10

[GeV]

u,d,s

c||

)*cc(b||

)*bb(

= 7, 8, 13 TeVspp, ALICE

ATLAS

CMS

LHCb

Fig. 1. Measured nfor diﬀerent species. Colors correspond to collision energies,

symbol shapes denote experiments. Error bars are uncertainties of the ﬁts. Circled

points are used for common ﬁts of the u,d,s and q¯qmesons. Results of the ﬁts are

shown by horizontal lines. From reference [10].

the form of Eq. 1, parameters nand Tare strongly correlated, therefore T

is ﬁxed to 254 MeV. This value is similar to many other studies conducted

at LHC energies and it can be somewhat diﬀerent at diﬀerent energies. It

is shown later that the derived conclusions are indiﬀerent to the exact value

of T, which is also checked by varying it by ±50 MeV in the analysis.

Several trends are visible in Figure 1. Particles produced in collisions

with higher √shave harder spectra (lower n). The magnitude of ndepends

文档加载中……请稍候！
如果长时间未打开，您也可以点击刷新试试。

下载文档到电脑，查找使用更方便

10 玖币 0人已下载

立即下载

摘要：

Missingbeautyofproton-protoninteractionsIakovAizenberg,AlexanderMilovDepartmentofPhysicsandAstrophysics,WeizmannInstituteofScience,Rehovot,761001,IsraelZviCitronDepartmentofPhysics,BenGurionUniversityoftheNegev,BeerSheva,8410501,IsraelReceivedOctober21,2022Fromrstprinciples,particleswiththesamequa...

展开>> 收起<<

Missing beauty of proton-proton interactions Iakov Aizenberg Alexander Milov Department of Physics and Astrophysics Weizmann Institute of Science.pdf

共6页,预览2页

还剩页未读，继续阅读

声明：本站为文档C2C交易模式，即用户上传的文档直接被用户下载，本站只是中间服务平台，本站所有文档下载所得的收益归上传人(含作者)所有。玖贝云文库仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对上载内容本身不做任何修改或编辑。若文档所含内容侵犯了您的版权或隐私，请立即通知玖贝云文库，我们立即给予删除！

Missing beauty of proton-proton interactions Iakov Aizenberg Alexander Milov Department of Physics and Astrophysics Weizmann Institute of Science

相关推荐

开通VIP享超值会员特权

作者详情

相关内容

热门标签

举报选择: