Speaker
Dr.
Andry Rakotozafindrabe
(CEA Saclay, IRFU, France)
Description
If used in the fixed-target mode, the multi-TeV LHC beams will allow the most energetic fixed-target experiments ever performed, including studies of high precision pp, pd and pA collisions at sqrt(s_NN) ~ 115 GeV as well as Pb-p and PbA collisions at sqrt(s_NN) ~ 72 GeV. In particular, AFTER@LHC -- for A Fixed-Target ExperRiment -- can greatly complement [1] existing collider experiments, in particular that of Brookhaven's Relativistic Heavy Ion Collider (RHIC) and the proposed electron-ion colliders (EIC).
We thus discuss the conception of a multi-purpose fixed-target experiment with the proton or lead-ion LHC beams extracted by a bent crystal. This mature extraction technique, which is being studied as a smart collimator solution for the LHC [2], offers an ideal way to obtain a clean and very collimated high-energy beam, without altering the performance of the LHC [2-4].
We have shown that the instantaneous luminosity achievable with AFTER using typical targets would surpass that of RHIC by more than 3 orders of magnitude. This provides a quarkonium, prompt photon and heavy-flavour observatory [1, 5] in pp and pA collisions where, by instrumenting the target-rapidity region, gluon and heavy-quark distributions of the proton, the neutron and the nuclei can be accessed at large x and even at x larger than unity in the nuclear case. In addition, the fixed-target mode has the advantage to allow for spin measurements with a polarized target [6] and for access over the full backward rapidity domain up to x_F close to (-1) [7]. The nuclear target-species versatility provides a unique opportunity to study the nuclear matter versus the hot and dense matter formed in heavy-ion collisions. Modern detection technology will allow for the study of quarkonium excited states, in particular chi_c and chi_b resonances as well as exotic states such as the Z^c pentaquark and double-charmed baryons thanks to the boost of the fixed-target mode [8].
In this talk, we will also show the results of the first fast simulations based on a LHCb-like detector used in the fixed-target mode at LHC. We will also discuss the connection with existing and future data from the LHCb SMOG runs, which can be considered as a low-density internal gas target.
References
[1] S. J. Brodsky, F. Fleuret, C. Hadjidakis and J. P. Lansberg, Phys. Rept. 108 522 (2013) 239.
[2] W. Scandale, et al. [LUA9 Collaboration], CERN-LHCC-2011-007, 2011.
[3] E. Uggerhoj, U. I. Uggerhoj, Nucl. Instr. Meth. B 234 (2005) 31.
[4] W. Scandale, it et al., Phys. Lett. B 703 (2011) 547-551.
[5] J. P. Lansberg, S. J. Brodsky, F. Fleuret and C. Hadjidakis, Few Body Syst. 53 (2012) 11.
[6] A. Rakotozafindrabe, et al., Phy. Part. Nucl. 45 (2014) 336 [arXiv:1301.5739 [hep-ex]].
[7] J. P. Lansberg, et al., EPJ Web Conf. 66 (2014) 11023 [arXiv:1308.5806 [hep-ex]].
[8] A. Rakotozafindrabe, et al., Nucl. Phys. A 904-905 (2013) 957c [arXiv:1211.1294 [nucl-ex]].
Primary author
Dr.
Andry Rakotozafindrabe
(CEA Saclay, IRFU, France)
Co-authors
Dr.
B. Genolini
(IPNO, Université Paris-Sud, CNRS/IN2P3, F-91406, Orsay, France)
Dr.
C. Hadjidakis
(IPNO, Université Paris-Sud, CNRS/IN2P3, F-91406, Orsay, France)
Dr.
C. Lorcé
(IPNO, Université Paris-Sud, CNRS/IN2P3, F-91406, Orsay, France; and IFPA, AGO Department, Université de Liège, Sart-Tilman, 4000 Liège, Belgium)
Dr.
E. Scomparin
(Dip. di Fisica and INFN Sez. Torino, Via P. Giuria 1, I-10125, Torino, Italy)
Dr.
Elena Gonzalez Ferreiro
(Universidade de Santiago de Compostela)
Dr.
F. Fleuret
(Laboratoire Leprince Ringuet, École Polytechnique, CNRS/IN2P3, 91128 Palaiseau, France)
Dr.
Ingo Schienbein
(LPSC)
Dr.
J.P. Didelez
(IPNO, Université Paris-Sud, CNRS/IN2P3, F-91406, Orsay, France)
Dr.
Jean-Philippe Lansberg
(IPN Orsay - Paris-Sud U - CNRS/IN2P3)
Dr.
M. Anselmino
(Dip. di Fisica and INFN Sez. Torino, Via P. Giuria 1, I-10125, Torino, Italy)
Dr.
P. Rosier
(IPNO, Université Paris-Sud, CNRS/IN2P3, F-91406, Orsay, France)
Dr.
R. Arnaldi
(Dip. di Fisica and INFN Sez. Torino, Via P. Giuria 1, I-10125, Torino, Italy)
Mr.
R. Mikkelsen
(Department of Physics and Astronomy, University of Aarhus, Denmark)
Dr.
R. Ulrich
(Karlsruhe Institute of Technology, Germany)
Dr.
S.J. Brodsky
(SLAC National Accelerator Lab., Theoretical Physics, Stanford University, Menlo Park, CA 94025, USA)
Dr.
U.I. Uggerhøj
(Department of Physics and Astronomy, University of Aarhus, Denmark)
Dr.
V. Chambert
(IPNO, Université Paris-Sud, CNRS/IN2P3, F-91406, Orsay, France)
Prof.
Y. Gao
(Center for High Energy Physics, Tsinghua University, Beijing 100084, China)
Dr.
Z. Yang
(Center for High Energy Physics, Tsinghua University, Beijing 100084, China)
