Abstract
In proton-proton collisions at LHC energies, Z 0 and low mass Higgs bosons would be produced with high and predominantly longitudinal boost with respect to the beam axis. This note describes a new analysis tool devised to handle this situation in cases when such bosons decay to a pair of τ -leptons. The tool reconstructs the rest frame of the τ + τ − pair by finding the boost that minimises the acollinearity between the visible τ decay products. In most cases this gives a reasonable approximation to the rest frame of the decaying boson. It is shown how the reconstructed rest frame allows for a new method of mass estimation. Also a considerable gain in sensitivity to helicity correlations is obtained by analysing the τ -jets in the reconstructed frame instead of using the laboratory momenta and energies, particularly when both τ -leptons decay hadronically.
Article PDF
Similar content being viewed by others
References
Particle Data Group collaboration, K. Nakamura et al., Review of particle physics, J. Phys. G. 37 (2010) 075021.
D0 collaboration, V. Abazov et al., Search for the standard model Higgs boson in τ final states, Phys. Rev. Lett. 102 (2009) 251801 [arXiv:0903.4800] [INSPIRE].
ATLAS collaboration, ATLAS sensitivity prospects for 1 Higgs boson production at the LHC running at 7, 8 or 9 TeV, PHYS-PUB-2010-015 (2010).
J. Baglio and A. Djouadi, Implications of the ATLAS and CMS searches in the channel pp → Higgs → τ + τ − for the MSSM and SM Higgs bosons, arXiv:1103.6247 [INSPIRE].
T. Pierzchala, E. Richter-Was, Z. Was and M. Worek, Spin effects in τ lepton pair production at LHC, Acta Phys. Polon. B 32 (2001) 1277 [hep-ph/0101311] [INSPIRE].
R. Ellis, I. Hinchliffe, M. Soldate and J. van der Bij, Higgs decay to τ + τ − a possible signature of intermediate mass Higgs bosons at the SSC, Nucl. Phys. B 297 (1988) 221 [INSPIRE].
A. Elagin, P. Murat, A. Pranko and A. Safonov, A new mass reconstruction technique for resonances decaying to τ τ , Nulc. Inst. Meth. in Phys. Res. A 654 (2011) 481.
T. Sjöstrand, S. Mrenna and P.Z. Skands, A brief introduction to PYTHIA 8.1, Comput. Phys. Commun. 178 (2008) 852 [arXiv:0710.3820] [INSPIRE].
N. Davidson, G. Nanava, T. Przedzinski, E. Richter-Was and Z. Was, Universal interface of TAUOLA technical and physics documentation, arXiv:1002.0543 [INSPIRE].
B. Mellado, W. Quayle and S.L. Wu, Prospects for the observation of a Higgs boson with H → τ + τ − → ℓ + ℓ − p-slash(t) associated with one jet at the LHC,Phys. Lett. B 611 (2005) 60 [hep-ph/0406095] [INSPIRE].
A. Aasvold, A study of mass reconstruction in Z 0 → τ + τ −, Master’s thesis, University of Bergen, Bergen Norway (2010).
CMS collaboration, S. Chatrchyan et al., Search for neutral MSSM Higgs bosons decaying to tau pairs in pp collisions at \( \sqrt {s} = {7}\;TeV \), Phys. Rev. Lett. 106 (2011) 231801 [arXiv:1104.1619] [INSPIRE].
ATLAS collaboration, Search for neutral MSSM Higgs bosons decaying to tau + τ − pairs in proton-proton collisions at \( \sqrt {s} = 7\;TeV \) with the ATLAS detector, ATLAS-CONF-2011-132 (2011).
CMS collaboration, Search for neutral Higgs bosons decaying to τ pairs in pp collisions at \( \sqrt {s} = {7}\;TeV \), PAS-HIG-11-020.
M. Davier, L. Duflot, F. Le Diberder and A. Rouge, The optimal method for the measurement of τ polarization, Phys. Lett. B 306 (1993) 411 [INSPIRE].
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1105.6003
Rights and permissions
Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License ( https://creativecommons.org/licenses/by-nc/2.0 ), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
About this article
Cite this article
Rosendahl, P.L., Burgess, T. & Stugu, B. A method to estimate the boson mass and to optimise sensitivity to helicity correlations of τ + τ − final states. J. High Energ. Phys. 2012, 43 (2012). https://doi.org/10.1007/JHEP01(2012)043
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP01(2012)043