Update README.md

Exercise-01/README.md

@@ -115,11 +115,11 @@ root shms_replay_production_0XXXX_5000.root
 T->Draw("", "P.cal.etottracknorm > 0.8 && P.cal.etottracknorm < 2 && P.ngcer.npeSum > .5 && P.gtr.dp > -10 && P.gtr.dp < 24")
 ```
 * This command will print out a number as `(long long) YYY`
-* **This number YYY is the "solution" to this exercise. Please email your answer to Sylvester (sjoosten@anl.gov)**.
+* **This number YYY is the "solution" to this exercise. If you like you can contact Sylvester on the Hall C Slack (hallc.slack.com) to check your answer.**.
 * Note that the (very rough) cut we do for good electrons in this example is the following:
     * Calorimeter E/P larger than 0.8 (most energy deposited in Calorimeter, electrons undergo an electromagnetic shower in the calorimeter and therefore leave behind more energy than pions.)
     * Calorimeter E/P smaller than 2 (remove unreasonable values)
     * Number of photo-electrons in the Noble Gas Cherenkov larger than 0.5 (Electrons emit Cherenkov radiation in the Noble Gas Cherenkov with N2 at this energy, pions don't.)
     * dp between -10% and 24%: Only use particles with a momentum fraction that is in the region where we understand the spectrometer optics
     * *In principle we should also make sure the particle comes from the target, but for this exercise this is unnecessary.*
-* *Contact Sylvester on the hallc Slack (hallc.slack.com) if you encounter any issues, or have any questions.*
+* *Contact Sylvester on the Hall C Slack (hallc.slack.com) if you encounter any issues, or have any questions.*