Comments on: Alexander Kusenko on sterile neutrinos, and the other afternoon talks http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/ private thoughts of a physicist and chessplayer Thu, 24 Dec 2009 08:50:26 +0000 http://wordpress.com/ hourly 1 By: dorigo http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/#comment-97510 dorigo Thu, 22 May 2008 19:58:30 +0000 http://dorigo.wordpress.com/?p=1256#comment-97510 carl, this puzzles me. electrons do not make it through a brick wall, let alone a star! You sure it wasn't electron <i> neutrinos</i> ? Cheers, T. carl, this puzzles me. electrons do not make it through a brick wall, let alone a star! You sure it wasn’t electron neutrinos ?

Cheers,
T.

]]> By: dorigo http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/#comment-97464 dorigo Wed, 21 May 2008 04:32:43 +0000 http://dorigo.wordpress.com/?p=1256#comment-97464 Hi Tripitaka, thank you... I will try to continue summarizing what I hear. Cheers, T. Hi Tripitaka, thank you… I will try to continue summarizing what I hear.

Cheers,
T.

]]> By: carlbrannen http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/#comment-97462 carlbrannen Wed, 21 May 2008 03:41:08 +0000 http://dorigo.wordpress.com/?p=1256#comment-97462 I was at the APSNW meeting in Portland on Saturday and there was a particle theory talk <a href="http://meetings.aps.org/Meeting/NWS08/Event/86727" rel="nofollow">Topological vector currents and neutron star kicks, James Charbonneau</a> on the problem of the velocities of pulsars. The author claimed that it is due to a jet of electrons exiting one end of the pulsar and not exiting the other end. He said that in addition to having velocity kicks, pulsars are oriented, that is, the excess velocity tends to be in the direction of their spin. I.e. these stars are handed. I was at the APSNW meeting in Portland on Saturday and there was a particle theory talk Topological vector currents and neutron star kicks, James Charbonneau on the problem of the velocities of pulsars. The author claimed that it is due to a jet of electrons exiting one end of the pulsar and not exiting the other end. He said that in addition to having velocity kicks, pulsars are oriented, that is, the excess velocity tends to be in the direction of their spin. I.e. these stars are handed.

]]> By: dorigo http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/#comment-97457 dorigo Tue, 20 May 2008 19:10:03 +0000 http://dorigo.wordpress.com/?p=1256#comment-97457 Good point DB. Indeed, 0v2B decay is something to watch for closely. Maybe sterile neutrinos are on shaky ground, but I found very compelling the model proposed by the speaker to explain the speed distribution in pulsars. The kind of order-of-magnitude, back-of-the-envelope arguments that I like because I can follow :) Cheers, T. Good point DB. Indeed, 0v2B decay is something to watch for closely. Maybe sterile neutrinos are on shaky ground, but I found very compelling the model proposed by the speaker to explain the speed distribution in pulsars. The kind of order-of-magnitude, back-of-the-envelope arguments that I like because I can follow :)

Cheers,
T.

]]> By: DB http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/#comment-97456 DB Tue, 20 May 2008 18:18:26 +0000 http://dorigo.wordpress.com/?p=1256#comment-97456 A very good test for sterile (Majorana) neutrinos would be the observation of neutrinoless double beta decay (violation of lepton number conservation) because no matter what mechanism gives rise to it, to occur it requires the existence of Majorana neutrinos. So far, no joy. Of course, non-observation of such a decay doesn't rule out sterile neutrinos, but their existence got dealt a bit of a blow when the analysis of solar neutrino oscillations showed that only three neutrinos were needed. The LSND experiment indicated the requirement for a fourth, sterile neutrino but Mini-Boone refuted this. So, all in all, sterile neutrinos are having some difficulty propagating :) A very good test for sterile (Majorana) neutrinos would be the observation of neutrinoless double beta decay (violation of lepton number conservation) because no matter what mechanism gives rise to it, to occur it requires the existence of Majorana neutrinos. So far, no joy.

Of course, non-observation of such a decay doesn’t rule out sterile neutrinos, but their existence got dealt a bit of a blow when the analysis of solar neutrino oscillations showed that only three neutrinos were needed. The LSND experiment indicated the requirement for a fourth, sterile neutrino but Mini-Boone refuted this. So, all in all, sterile neutrinos are having some difficulty propagating :)

]]> By: Tripitaka http://dorigo.wordpress.com/2008/05/20/alexander-kusenko-on-sterile-neutrinos-and-the-other-afternoon-talks/#comment-97442 Tripitaka Tue, 20 May 2008 11:57:04 +0000 http://dorigo.wordpress.com/?p=1256#comment-97442 Very nice summaries and suitable for the uninitiated like me who will never attend such conferences, thanks Very nice summaries and suitable for the uninitiated like me who will never attend such conferences, thanks

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