Neutron Electric Dipole Moment and Tensor Charges from Lattice QCD.

نویسندگان

  • Tanmoy Bhattacharya
  • Vincenzo Cirigliano
  • Rajan Gupta
  • Huey-Wen Lin
  • Boram Yoon
چکیده

We present lattice QCD results on the neutron tensor charges including, for the first time, a simultaneous extrapolation in the lattice spacing, volume, and light quark masses to the physical point in the continuum limit. We find that the "disconnected" contribution is smaller than the statistical error in the "connected" contribution. Our estimates in the modified minimal subtraction scheme at 2 GeV, including all systematics, are g_{T}^{d-u}=1.020(76), g_{T}^{d}=0.774(66), g_{T}^{u}=-0.233(28), and g_{T}^{s}=0.008(9). The flavor diagonal charges determine the size of the neutron electric dipole moment (EDM) induced by quark EDMs that are generated in many new scenarios of CP violation beyond the standard model. We use our results to derive model-independent bounds on the EDMs of light quarks and update the EDM phenomenology in split supersymmetry with gaugino mass unification, finding a stringent upper bound of d_{n}<4×10^{-28} e cm for the neutron EDM in this scenario.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Neutron electric dipole moment on the lattice

We carry out a feasibility study toward a lattice QCD calculation of the neutron electric dipole moment (NEDM) in the presence of the θ term using two different approaches. In the first method, we calculate the CP-odd electromagnetic form factor F3, which becomes the NEDM in the zero momentum transfer limit. At the first order in θ , we derive a formula connecting the lattice three-point functi...

متن کامل

Electric Dipole Moment of the Neutron from 2+1 Flavor Lattice QCD.

We compute the electric dipole moment d(n) of the neutron from a fully dynamical simulation of lattice QCD with 2+1 flavors of clover fermions and nonvanishing θ term. The latter is rotated into a pseudoscalar density in the fermionic action using the axial anomaly. To make the action real, the vacuum angle θ is taken to be purely imaginary. The physical value of dd(n) is obtained by analytic c...

متن کامل

The Neutron Electric Dipole Moment using Nf=2+1+1 twisted mass fermions

We evaluate the neutron electric dipole moment |~ dN | using lattice QCD techniques. The gauge configurations analyzed are produced by the European Twisted Mass Collaboration using Nf=2+1+1 twisted mass fermions at one value of the lattice spacing of a ≃ 0.082 fm and a light quark mass corresponding to mπ ≃ 373 MeV. Our approach to extract the neutron electric dipole moment is based on the calc...

متن کامل

Neutron electric dipole moment with two flavors of domain wall fermions∗

We present a study of the neutron electric dipole moment (~ dN) within the framework of lattice QCD with two flavors of light quarks. The dipole moment is sensitive to the topological structure of the gauge fields, so accuracy can only be achieved by using dynamical, or sea quark, calculations. The topological charge (distribution) evolves slowly in these calculations, leading to systematic unc...

متن کامل

An upper limit to the electric dipole moment of the neutron from lattice QCD

Presented the talk. is odd under both of them. This breaking can produce a nonzero value of dn, the electric dipole moment of the neutron [1], dn ≈ 8 · 10 θe · cm. The experimental upper limit is [2] dn|exp < 6 · 10e · cm which implies θ < ∼10. This is a small number and its smallness is not protected by any known symmetry. An alternative possibility for having dn 6= 0 could be a spontaneous br...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Physical review letters

دوره 115 21  شماره 

صفحات  -

تاریخ انتشار 2015