The probability density function (PDF) is constructed from the time distributions of signal and backgrounds and the relations among time, time uncertainty, mass, and mass difference variables.

根据信号、本底的时间分布以及时间、时间误差、质量、质量差等变量之间的关系，构建概率密度函数。

youdao

How could one explain this difference in mass?

那么要如何解释质量上的这个差异呢？

youdao

I am using fancy words today. And the moment of inertia — the difference with a mass is that the moment of inertia is defined about some axis.You choose an axis.

我今天措辞别致，转动惯量就是——，与质量不同，转动惯量的定义跟旋转轴有关，选定一个旋转轴。

youdao

The difference in speed also means a difference in mass of 50%.

VOA: special.2009.01.20

The frequency at which it happens is related to a small but significant difference between the mass of the particle and its antiparticle.

ECONOMIST: Cosmology and particle physics

To assess the contribution from melting ice sheets, scientists try to measure "mass balance, " which is the difference between the annual snow that falls on the permanent ice sheets each year, and the total mass of ice that melts or breaks off the sheets.

WSJ: Polar Ice Sheets Melt at Faster Pace

On average, men have 40% more fat-free mass than women, which is similar to the difference in gorillas, a species in which males unquestionably compete with other males for exclusive sexual access to females.

ECONOMIST: Masculine traits