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Title: Probing CP violation in $$h\rightarrow\gamma\gamma$$ with converted photons

We study Higgs diphoton decays, in which both photons undergo nuclear conversion to electron- positron pairs. The kinematic distribution of the two electron-positron pairs may be used to probe the CP violating (CPV) coupling of the Higgs to photons, that may be produced by new physics. Detecting CPV in this manner requires interference between the spin-polarized helicity amplitudes for both conversions. We derive leading order, analytic forms for these amplitudes. In turn, we obtain compact, leading-order expressions for the full process rate. While performing experiments involving photon conversions may be challenging, we use the results of our analysis to construct experimental cuts on certain observables that may enhance sensitivity to CPV. We show that there exist regions of phase space on which sensitivity to CPV is of order unity. As a result, the statistical sensitivity of these cuts are verified numerically, using dedicated Monte-Carlo simulations.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Univ. of Cincinnati, Cincinnati, OH (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  2. Cornell Univ., Ithaca, NY (United States)
  3. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  4. Chinese Academy of Sciences (CAS), Beijing (China); Univ. of California, Berkeley, CA (United States)
  5. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  6. Univ. of Cincinnati, Cincinnati, OH (United States)
Publication Date:
OSTI Identifier:
1156494
Report Number(s):
FERMILAB-PUB--13-540-T
Journal ID: ISSN 1029-8479; arXiv eprint number arXiv:1312.2955
Grant/Contract Number:
AC02-07CH11359
Type:
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2014; Journal Issue: 4; Journal ID: ISSN 1029-8479
Publisher:
Springer Berlin
Research Org:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS Higgs physics; Beyond Standard Model; CP violation