Bin Number

Mean Decay Length (s)

Mean Decay Time (s)

t (s)

1

5.25320 E12

5.26699 E12

3.8086 E13

2

1.19318 E11

1.19523 E11

6.9891 E13

3

1.11187 E11

1.11317 E11

5.3804 E13

4

1.15704 E11

1.15802 E11

4.7608 E13

5

1.39178 E11

1.39267 E11

4.9883 E13

6

1.36513 E11

1.36582 E11

4.3569 E13

7

1.69185 E11

1.69254 E11

4.8160 E13

8

1.49663 E11

1.49713 E11

3.8846 E13

9

1.58498 E11

1.58543 E11

3.7587 E13

10

2.00322 E11

2.00369 E11

4.3423 E13

11

1.34427 E11

1.34454 E11

2.7074 E13

12

1.86430 E11

1.86463 E11

3.4965 E13

13

1.89248 E11

1.89277 E11

3.3128 E13

14

1.56065 E11

1.56086 E11

2.5604 E13

15

2.04128 E11

2.04153 E11

3.2064 E13

16

2.51898 E11

2.51925 E11

3.7223 E13

17

3.89694 E11

3.89732 E11

5.4373 E13

18

2.52780 E11

2.52802 E11

3.3479 E13


This should make a bit of sense. All of these events are productions and
decays of the charmed meson. The time between creation and decay of a
particle is called the lifetime. Because the lifetime of a type of
particle is an identifying characteristic, all of these events have that
one thing in common; the lifetime.
What is the average
value of t?
t = 4.1598x10^{13} ± 1.1014x10^{13}
s
This value should look familiar; it is the accepted value for the lifetime
of the charmed meson! Do you recall using it earlier to predict decay
lengths?
Actually the accepted value for the lifetime is
4.15x10^{13} ±
0.04x10^{13} seconds. The uncertainty in this
number is much better than yours. The most important difference is the
size of the dataset. The accepted value is based on thousands of data
points; your value, only 18. More data yield more precise answers with
smaller uncertainties.
So . . . now
what?
