Speaker
Mate Csanad
(for the TOTEM Collaboration)
Description
The TOTEM experiment at LHC measured the differential cross-section of elastic p+p scattering at 7 TeV, with the help of Roman Pot detectors placed as close as seven times the transverse beam size from the outgoing beams [1]. Results indicate an initial exponential decrease of dsigma/dt, followed by a significant diffractive minimum at |t| = (0.53 +- 0.01(stat) +- 0.01(syst)) GeV**2. For large |t| values, the cross-section exhibits a power law behavior.
By extrapolation of measured elastic p+p cross sections to |t| = 0, TOTEM obtained a total elastic scattering cross-section of 24.8 +- 0.2(stat) +- 1.2(syst)) mb [2]. Applying the optical theorem and using the luminosity measurement from CMS, a total proton-proton cross-section of (98.3 +- 0.2(stat) +- 2.8(syst)) mb was deduced.
TOTEM also measured the charged particle pseudorapidity density dN/deta in p+p collisions at 7 TeV, in the pseudorapidity range 5.3 < |eta| < 6.4 [3]. This measurement extends the analogous measurements performed by the other LHC experiments to the so far unexplored forward eta range.
References:
[1] "Proton-proton elastic scattering at the LHC energy of sqrt(s)=7TeV"
The TOTEM Collaboration (G. Antchev et al.), Europhys. Lett., 95 (2011) 41001
[2] "First measurement of the total proton-proton
cross-section at the LHC energy of sqrt(s) = 7 TeV"
The TOTEM Collaboration (G. Antchev et al.), Europhys. Lett., 96 (2011) 21002
[3] "Measurement of the forward charged particle pseudorapidity density in pp collisions at sqrt(s) = 7 TeV with the TOTEM experiment"
The TOTEM Collaboration (G. Antchev et al.), CERN-PH-EP-2012-106
Primary author
Mate Csanad
(for the TOTEM Collaboration)
