Wednesday, March 31, 2010

Mesin Kiamat Konon

Peristiwa bersejarah berlaku semalam di Large Hadron Collider (LHC) . Pelanggaran 7 TeV berlaku. Setakat ini, LHC masih belum ditelan lohong hitam !

Khabarnya dianggarkan terdapat 600000 collision events!

Tak sabar menantikan analisis fizik mengenainya ;-)

Monday, March 29, 2010

Publish Juga

Saya mendapat emel daripada kawan dari UTAR pagi tadi. Berita gembira, kertas penyelidikan yang saya tulis bersama rakan-rakan telah dipersetujui untuk di" publish "kan. Syaratnya, kena "present" dahulu di konferen tidak lama lagi.

Tapi oleh sebab ini, saya mewakilkan sahaja kepada seorang lagi sahabat. ;-)

Wednesday, March 24, 2010

Nota untuk diri

How do scientists know when their experimental results add up to a discovery?

  • sigma;the unit that describes how reliable a result is
  • Scientists refer to sigma as the "standard deviation." It is the decisive parameter of the Gaussian curve, a mathematical function that describes the distribution of data from many simple experiments. Citing a certain number of sigma directly translates into a probability. Three sigma, for example, is equivalent to a 99.75 percent chance that a future experiment will yield a compatible result
  • Identifying a new particle and determining the significance of its signal is quite different from rolling a pair of dice and calculating the probability of the score. Particle physicists have to study background events, which are created by other particles and leave similar signals.
  • Scientists need to know characteristic details of both signal and background events to filter the data and obtain a sharper image. If plenty of "photos" and good filtering techniques exist, physicists can reconstruct the "image" of a new particle.
  • Simulations are important in order to judge how much an anticipated signal could differ from the expected background noise.
  • To calculate the significance of a discovery, we actually simulate a large ensemble of pseudo experiments. For each pseudo experiment we generate a certain number of events that we would have seen in the detector
  • You have to understand exactly how your detector is working to determine the background with particular uncertainties