Comments on: Spin-parity analysis of the X(3872) http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/ private thoughts of a physicist and chessplayer Thu, 24 Dec 2009 08:50:26 +0000 http://wordpress.com/ hourly 1 By: A new precise measurement of the X particle « A Quantum Diaries Survivor http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-99706 A new precise measurement of the X particle « A Quantum Diaries Survivor Thu, 14 Aug 2008 20:37:16 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-99706 [...] by dorigo in news, physics, science. Tags: BaBar, charmonium, X(3872) trackback Remember the X(3872) ? It is a new neutral particle decaying into a J/Psi meson and a pair of pions, which was [...] [...] by dorigo in news, physics, science. Tags: BaBar, charmonium, X(3872) trackback Remember the X(3872) ? It is a new neutral particle decaying into a J/Psi meson and a pair of pions, which was [...]

]]> By: dorigo http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-3680 dorigo Tue, 04 Jul 2006 18:10:11 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-3680 Hi Joachim, thanks! And yes, probability and certainty are two different things... And as far as penalties go, tonight Italy meets Germany and... Well, Italy is not better than England for penalty kicks! I hope the game ends sooner! Cheers, T. Hi Joachim,
thanks!
And yes, probability and certainty are two different things… And as far as penalties go, tonight Italy meets Germany and… Well, Italy is not better than England for penalty kicks! I hope the game ends sooner!
Cheers,
T.

]]> By: Joachim http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-3677 Joachim Tue, 04 Jul 2006 16:27:09 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-3677 Hi Alexey, Belle only considered angular distributions of 0++, 1++ and 2++, since only those fit into the description of a decay via a rho (e.g. C=+1) and in addition having a relative angular momentum of JPsi and rho L=0 (kicking 2-+, 1-+ and 0-+) which can be accessed by the the mass spectrum of the PiPi system. While this is clearly favored, also by CDF data, others (e.g. L=1) are not ruled out. This analysis takes all sensible JPC assumptions, without the knowledge of other experiments (e.g. also JP-) states were tested, which is in the meantime ruled out by Babar's and Belle's X->JPsi gamma. Cheers, Joachim PS: great post Tommaso! :-) PPS: in my opinion data also favors 1++, but there is still quite a way to go to prove that (it's different to say that England sucks in penalties from proving that they will lose every time :-) ) Hi Alexey,

Belle only considered angular distributions of 0++, 1++ and 2++, since only those fit into the description of a decay via a rho (e.g. C=+1) and in addition having a relative angular momentum of JPsi and rho L=0 (kicking 2-+, 1-+ and 0-+) which can be accessed by the the mass spectrum of the PiPi system.
While this is clearly favored, also by CDF data, others (e.g. L=1) are not ruled out. This analysis takes all sensible JPC assumptions, without the knowledge of other experiments (e.g. also JP-) states were tested, which is in the meantime ruled out by Babar’s and Belle’s X->JPsi gamma.

Cheers,
Joachim

PS: great post Tommaso! :-)
PPS: in my opinion data also favors 1++, but there is still quite a way to go to prove that (it’s different to say that England sucks in penalties from proving that they will lose every time :-) )

]]> By: dorigo http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-674 dorigo Wed, 14 Jun 2006 07:27:27 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-674 Hello Alexey, yes, Belle is consistent with the 1++ hypothesis, but AFAIK has not done a full-fledged test, which would be even easier with the polarized state of the produced X in B decays. The reason why a 2-+ case has been considered by CDF is that it is the most obvious thing to do with a potential ccbar bound state. And the data do not disprove that spin-parity assignment yet. However, I do believe in the explanation of the molecular D -D* state, it fits the bill and the charmonium hypothesis is instead contradictory. The matter will be settled in a few months, I think. Cheers, T. Hello Alexey,

yes, Belle is consistent with the 1++ hypothesis, but AFAIK has not done a full-fledged test, which would be even easier with the polarized state of the produced X in B decays.

The reason why a 2-+ case has been considered by CDF is that it is the most obvious thing to do with a potential ccbar bound state. And the data do not disprove that spin-parity assignment yet. However, I do believe in the explanation of the molecular D -D* state, it fits the bill and the charmonium hypothesis is instead contradictory.

The matter will be settled in a few months, I think.

Cheers,
T.

]]> By: Alexey Petrov http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-670 Alexey Petrov Wed, 14 Jun 2006 03:24:25 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-670 Hmm.. I thought Belle's angular analysis was only consistent with 1++ quantum numbers, which is good for molecular interpretation. Is there a reason for CDF to leave 2-+ as a viable interpretation? Is that because Belle has all X's come from B-decays and CDF doing inclusive analysis? Hmm.. I thought Belle’s angular analysis was only consistent with 1++ quantum numbers, which is good for molecular interpretation. Is there a reason for CDF to leave 2-+ as a viable interpretation? Is that because Belle has all X’s come from B-decays and CDF doing inclusive analysis?

]]> By: Collider Blog » Tommaso’s Tips http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-654 Collider Blog » Tommaso’s Tips Sun, 11 Jun 2006 21:34:03 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-654 [...] First, he described with wonderful clarity and simplicity the analysis of the angular decay distributions of the X(3872). This is a very nice result coming from CDF which helps identify the nature of this peculiar object. See his post for the discussion, to which I would add that this kind of physics is rich and interesting, if not the most popular in HEP. However, if you want really to know what’s going on, you need to pay attention - if new particles are found at the LHC then the same kinds of analyses will be needed to identify them. Also, I agree that it is slightly embarassing that CDF had a nice signal in the data but did not spot this until after Belle did. We are not being vigilant enough, perhaps… [...] [...] First, he described with wonderful clarity and simplicity the analysis of the angular decay distributions of the X(3872). This is a very nice result coming from CDF which helps identify the nature of this peculiar object. See his post for the discussion, to which I would add that this kind of physics is rich and interesting, if not the most popular in HEP. However, if you want really to know what’s going on, you need to pay attention – if new particles are found at the LHC then the same kinds of analyses will be needed to identify them. Also, I agree that it is slightly embarassing that CDF had a nice signal in the data but did not spot this until after Belle did. We are not being vigilant enough, perhaps… [...]

]]> By: dorigo http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-649 dorigo Sun, 11 Jun 2006 19:58:07 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-649 That is right, there is a lot to learn in low energy QCD and things such as the X may be places where real discoveries are made. If - as Belle first claimed without too much emphasis nor investigation, and as CDF data seem to favor - the X is a 1++ state, a whole new chapter opens in the understanding of "not-so-elementary" particles. Complex objects, that is. Just imagine, a whole new Mendelejev table to fill up ! Cheers, T. That is right, there is a lot to learn in low energy QCD and things such as the X may be places where real discoveries are made. If – as Belle first claimed without too much emphasis nor investigation, and as CDF data seem to favor – the X is a 1++ state, a whole new chapter opens in the understanding of “not-so-elementary” particles. Complex objects, that is. Just imagine, a whole new Mendelejev table to fill up !
Cheers,
T.

]]> By: Michael Schmitt http://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-644 Michael Schmitt Sun, 11 Jun 2006 17:29:09 +0000 https://dorigo.wordpress.com/2006/06/09/spin-parity-analysis-of-the-x3872/#comment-644 Ciao Tommaso, this is a very nice explanation of a relatively difficult analysis. And I agree this is quite interesting and relevant for non-perturbative QCD. We have a professor here at Northwestern who knows a lot about the charm system to we have often discussed whether these meson "molecules" really might exist, or not. It seems like the experts have a wide range of opinions, which helps make this area of investigation more fun! Certainly it is not as cut-and-dried as things like electroweak symmetry breaking... warm regards, Michael Ciao Tommaso,

this is a very nice explanation of a relatively difficult analysis. And I agree this is quite interesting and relevant for non-perturbative QCD. We have a professor here at Northwestern who knows a lot about the charm system to we have often discussed whether these meson “molecules” really might exist, or not. It seems like the experts have a wide range of opinions, which helps make this area of investigation more fun! Certainly it is not as cut-and-dried as things like electroweak symmetry breaking…

warm regards,
Michael

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