E. Dimovasili

Proton-proton elastic scattering at the LHC energy of \chem{\sqrt{s} = 7\,TeV}

Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at √ s = 7 TeV in dedicated runs with the Roman Pot detectors placed as close as seven times the transverse beam size (σbeam) from the outgoing beams. After careful study of the accelerator optics and the detector alignment, |t|, the square of four-momentum transferred in the elastic scattering process, has been determined with an uncertainty of δt = 0.1 GeV p |t|. In this letter, first results of the differential cross-section are presented covering a |t|-range from 0.36 to 2.5 GeV 2 . The differential cross-section in the range 0.36 < |t| < 0.47 GeV 2 is described by an exponential with a slope parameter B =( 23.6 ± 0.5 stat ± 0.4 syst )G eV −2 , followed by a significant diffractive minimum at |t| =( 0.53 ± 0.01 stat ± 0.01 syst )G eV 2 .F or|t|-values larger than ∼ 1. 5G eV 2 , the cross-section exhibits a power law behaviour with an exponent of −7.8 ± 0.3 stat ± 0.1 syst . When compared to predictions based on the different available models, the data show a strong discriminative power despite the small t-range covered. open access Copyright c EPLA, 2011

Elastic Scattering and Total Cross-Section in p+p Reactions As Measured by the LHC Experiment TOTEM at √ s =7 TeV

Tamas Csorgő4 for the TOTEM Collaboration: G. Antchev,∗) P. Aspell,8 I. Atanassov,8,∗)V. Avati,8 J. Baechler,8 V. Berardi,5b,5a M. Berretti,7b E. Bossini,7b M. Bozzo,6b,6a P. Brogi,7b E. Brucken,3a,3b A. Buzzo,6a F. S. Cafagna,5a M. Calicchio,5b,5a M. G. Catanesi,5a C. Covault,9 M. Csanad,4,∗∗) M. Deile,8 E. Dimovasili,8 M. Doubek,1b K. Eggert,9 V. Eremin,∗∗∗) R. Ferretti,6a,6b F. Ferro,6a A. Fiergolski,†) F. Garcia,3a S. Giani,8 V. Greco,7b,8 L. Grzanka,8,††) J. Heino,3a T. Hilden,3a,3b M. R. Intonti,5a M. Janda,1b J. Kaspar,1a,8 J. Kopal,1a,8 V. Kundrat,1a K. Kurvinen,3a S. Lami,7a G. Latino,7b R. Lauhakangas,3a T. Leszko,† E. Lippmaa,2 M. Lokajicek,1a M. Lo Vetere,6b,6a F. Lucas Rodŕiguez,8 M. Macŕi,6a L. Magaletti,5b,5a G. Magazzu,7a A. Mercadante,5b,5a M. Meucci,7b S. Minutoli,6a F. Nemes,4,∗∗) H. Niewiadomski,8 E. Noschis,8 T. Novak,4,† † †) E. Oliveri,7b F. Oljemark,3a,3b R. Orava,3a,3b M. Oriunno,8,‡) K. Osterberg,3a,3b P. Palazzi,7b A.-L. Perrot,8 E. Pedreschi,7a J. Petajajarvi,3a J. Prochazka,1a M. Quinto,5a E. Radermacher,8 E. Radicioni,5a F. Ravotti,8 E. Robutti,6a L. Ropelewski,8 G. Ruggiero,8 H. Saarikko,3a,3b G. Sanguinetti,7a A. Santroni,6b,6a A. Scribano,7b G. Sette,6b,6a W. Snoeys,8 F. Spinella,7a J. Sziklai,4 C. Taylor,9 N. Turini,7b V. Vacek,1b M. Vitek,1b J. Welti,3a,b J. Whitmore10

Diffraction at TOTEM

The TOTEM experiment at the LHC measures the total proton-proton cross section with the luminosity-independent method and the elastic proton-proton cross-section over a wide |t|-range. It also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage of the large common rapidity coverage for charged and neutral particle detection and the large variety of trigger possibilities even at large luminosities. TOTEM will take data under all LHC beam conditions including standard high luminosity runs to maximize its physics reach. This contribution describes the main features of the TOTEM physics programme including measurements to be made in the early LHC runs. In addition, a novel scheme to extend the diffractive proton acceptance for high luminosity runs by installing proton detectors at IP3 is described.