2024-03-28T15:10:17Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/234982017-01-20T08:15:36Zcom_10261_61com_10261_4col_10261_314
Semileptonic decays of light quarks beyond the Standard Model
González-Alonso, Martín
Jenkins, James P.
Cirigliano, Vincenzo
We describe non-standard contributions to semileptonic processes in a model independent way in terms of in SU(2)(L) x U(1)(Y) invariant effective lagrangian at the weak scale, front which we derive the low-energy effective lagrangian governing muon and beta decays. We find that the deviation from Cabibbo universality, Delta(CKM) equivalent to vertical bar V-ud vertical bar(2) + vertical bar V-us vertical bar(2) + vertical bar V-ub vertical bar(2) - 1, receives contributions from four effective operators. The phenomenological bound Delta(CKM) = (-1 +/- 6) x 10(-4) provides strong constraints on all four operators, corresponding to art effective scale Lambda > 11 TeV (90% CL). Depending on the operator, this constraint is at the same level or better then the Z pole observables. Conversely, precision electroweak constraints alone would allow universality violations as large as Delta(CKM) = -0.01 (90% CL). An observed Delta(CKM) not equal 0 at this level Could be explained in terms of a single four-fermion operator which is relatively poorly constrained by electroweak precision measurements.
We thank the Institute for Nuclear Theory at the University of Washington and the
Aspen Center for Physics for their hospitality during the completion of this work. We thank
Antonio Pich and Jorge Portolés for useful comments. M.G.-A. thanks A. Filipuzzi for useful
comments and discussions and the LANL T-2 Group for its hospitality and partial support.
This work has been supported in part by the EU RTN network FLAVIAnet [Contract No.
MRTN-CT-2006-035482], by MICINN, Spain [Grants FPU No. AP20050910, FPA2007-
60323 and Consolider-Ingenio 2010 Programme CSD2007-00042 -CPAN-] (M. G.-A.). This
work was performed under the auspices of the National Nuclear Security Administration
of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No.
DE-AC52-06NA25396, and was supported in part by the LANL LDRD program.
Peer reviewed
2010-04-26T10:53:46Z
2010-04-26T10:53:46Z
2010-05-01
artículo
http://purl.org/coar/resource_type/c_6501
Nuclear Physics - Section B 830 (1-2): 95-115 (2010)
0550-3213
http://hdl.handle.net/10261/23498
10.1016/j.nuclphysb.2009.12.020
en
http://dx.doi.org/ 10.1016/j.nuclphysb.2009.12.020
open
630090 bytes
application/pdf
Elsevier