| 2010-10-21 12:47:23 |
First scientific publication from LHC 7 TeV run appears in Phys. Rev. Letters!
Since 1995 group from Yerevan Physics Institute headed by Albert
Sirunyan participates in the preparation of the Compact Muon Solenoid
(CMS ) experiment.
YerPhI group was involved in the detectors design and construction, data
analysis software development as well as in test beam data taking &
analysis. Now the group actively participate in the ongoing LHC physics
program ( shifts , data taking and analysis ).
After the successful start of the CMS experiment in December 2009, the
first results collected at 0.9 and 2.36 TeV already indicated something
surprising: the number of created particles grew faster with collision
energy than expected.
On 30th of March, the CMS collaboration was excited to see the first
proton-proton collisions at 7 TeV, celebrating the new world record of
center-of-mass energy.
The data for this study are drawn from an integrated luminosity of 1.1
μb-1 recorded with the CMS experiment on 30 March 2010, during the first
hour of the LHC operation at √s =7 TeV.
Figure 1.Article header
Figure 2. Pseudorapidity distributions of charged particles compared with earlier measurements at 0.9 and 2.36 TeV.
It was found that the number of charged particles emitted in a given
direction has increased by about 66% compared to the data taken at 0.9
TeV. That exceeds the predictions of many Monte-Carlo simulations and
phenomenological models available by 40%, thus starting an activity
geared to refine these models.
These studies are the first steps in the exploration of particle
production at the new center-of-mass energy frontier, and contribute to
the understanding of the dynamics in soft hadronic interactions.
Thanks to financial support of Ministry of Economy RA for possibility
of visits young scientists to CERN and inclusion members of armenian
group ( V.Khachatryan, A.Sirunyan, A.Tumasyan) in authors list of
this important paper.