[SLAC] [SLAC Pubs and Reports]

Right-Handed Currents in B Decay Revisited


We critically re-examine the case for and against a sizeable right-handed component in the $b\to c$ charged current coupling with a strength $\xi$ relative to the conventional left-handed current. Using data from CLEO on the decay $B\to D^*\ell \nu$, as well as our knowledge of $V_{cb}$ extracted from both inclusive and exclusive processes, we are able to determine the presently allowed parameter space for $\xi$ via HQET. We then identify several observables which could be measured at $B$ factories to either strengthen these constraints or otherwise observe right-handed currents. This parameter space region is found to be consistent with the low degree of $\Lambda_b$ polarization as determined by ALEPH as well as the measurements of the charged lepton and neutrino energy spectra from $b$ decay made by L3. We discuss how future measurements of semileptonic decay distributions may distinguish between exotic $\Lambda_b$ depolarization mechanisms and the existence of right-handed currents. Within the parameter space allowed by CLEO, using the Left-Right Symmetric Model as a guide, we perform a detailed search for specific sub-regions which can lead to a reduction in both the $B$ semileptonic branching fraction as well as the the average yield of charmed quarks in $B$ decay. The results provide a concrete realization of an earlier suggestion by Voloshin but may lead to potential difficulties with certain penguin mediated decay processes.

(Equations render on Windows, Mac OS, AIX, Linux, Solaris, and IRIX with the techexplorer plug-in.)

Full Text


Compressed PostScript


The PDF version of this document was distilled from a PostScript file most likely created from LaTeX source which used Type 3 fonts. The resultant PDF may be unreadable on the screen at the default viewing magnification (fonts will appear bitmapped, jagged), though the type will be legible at higher magnifications.

Despite the cosmetic problems resulting from the use Type 3 fonts in the original source file, such PDF files print without problems; likewise, the onscreen text is searchable and selectable.

More Information

Full bibliographic data for this document, including its complete author list, is (or soon will be) available from SLAC's SPIRES-HEP Database.

Please report problems with this file to posting@slac.stanford.edu. The SLAC preprint inventory is provided by the SLAC Technical Publications Department.
Page generated 04 Apr 2001 @ 15:10 PDT by htmlme.pl