Comments on: The Higgs almost excluded at 160 GeV!! http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/ private thoughts of a physicist and chessplayer Thu, 24 Dec 2009 08:50:26 +0000 http://wordpress.com/ hourly 1 By: 115 GeV Higgs: is evidence piling up ? « A Quantum Diaries Survivor http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-95642 115 GeV Higgs: is evidence piling up ? « A Quantum Diaries Survivor Sat, 29 Mar 2008 13:35:35 +0000 http://dorigo.wordpress.com/?p=1121#comment-95642 [...] the Tevatron Run II experiments have started to produce results of the search for a Standard Model Higgs boson, we have had a chance to compare observed and expected limits, and indulge in vacuous but [...] [...] the Tevatron Run II experiments have started to produce results of the search for a Standard Model Higgs boson, we have had a chance to compare observed and expected limits, and indulge in vacuous but [...]

]]> By: island http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93342 island Thu, 07 Feb 2008 20:19:51 +0000 http://dorigo.wordpress.com/?p=1121#comment-93342 <i>Island, sticks and stones</i>… might break your bones, but a null result is only a good thing... :) Island, sticks and stones… might break your bones, but a null result is only a good thing… :)

]]> By: dorigo http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93331 dorigo Thu, 07 Feb 2008 14:22:10 +0000 http://dorigo.wordpress.com/?p=1121#comment-93331 Island, sticks and stones... ;-) Jim, if we found the Higgs at, say, 300 GeV, that would really be a fly in the face of Supersymmetry. Instead, the SM could accommodate it with some stretch of one or two electroweak measurements, but it would also imply that the SM must break down at a relatively light energy scale (above a TeV), lest we conclude that we understand nothing at all about the theory. About light susy, yes, the LHC can in principle see it in a few days of running, for a particular combination of SUSY parameters. Not true for all cases though. Nature may have made it hard for us to find SUSY even if it is "light". As for dark matter, I think we understand too little about our cosmos yet. I do not believe in SUSY however, so whatever else fits the bill is ok for me :) Cheers, T. Island, sticks and stones… ;-)

Jim, if we found the Higgs at, say, 300 GeV, that would really be a fly in the face of Supersymmetry. Instead, the SM could accommodate it with some stretch of one or two electroweak measurements, but it would also imply that the SM must break down at a relatively light energy scale (above a TeV), lest we conclude that we understand nothing at all about the theory.

About light susy, yes, the LHC can in principle see it in a few days of running, for a particular combination of SUSY parameters. Not true for all cases though. Nature may have made it hard for us to find SUSY even if it is “light”.

As for dark matter, I think we understand too little about our cosmos yet. I do not believe in SUSY however, so whatever else fits the bill is ok for me :)

Cheers,
T.

]]> By: Jim Graber http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93327 Jim Graber Thu, 07 Feb 2008 11:19:51 +0000 http://dorigo.wordpress.com/?p=1121#comment-93327 Hi Tommaso, Thanks for your illuminating response. I will take your word that both SM and MSSM want the lightest possible Higgs, contrary to my previous understanding. But I am still a very confused football fan. First of all, what does it mean if we find a heavy Higgs instead of a light one? Another thing I have heard is that if low energy supersymmetry (LES) exists, LHC will see it faster than the Higgs, because the signatures are so much more obvious. Is that true? Maybe I will root for LES and a nice neutralino to match the dark matter. That used to be the mainstream favorite, did it not? But now I hear that the precision measurements disfavor LES. Is that true? Or maybe I will root for axions. I’d like to see them, not only for PQ, but also because it would be much easier to see them than to prove they don’t exist. Of course, this result comes not from LHC, if it comes at all. Who do you bet on in the dark matter game? Thanks again for your time and all the fun. Jim Graber Hi Tommaso,
Thanks for your illuminating response. I will take your word that both SM and MSSM want the lightest possible Higgs, contrary to my previous understanding. But I am still a very confused football fan. First of all, what does it mean if we find a heavy Higgs instead of a light one?
Another thing I have heard is that if low energy supersymmetry (LES) exists, LHC will see it faster than the Higgs, because the signatures are so much more obvious. Is that true?
Maybe I will root for LES and a nice neutralino to match the dark matter. That used to be the mainstream favorite, did it not? But now I hear that the precision measurements disfavor LES. Is that true?
Or maybe I will root for axions. I’d like to see them, not only for PQ, but also because it would be much easier to see them than to prove they don’t exist. Of course, this result comes not from LHC, if it comes at all.
Who do you bet on in the dark matter game?
Thanks again for your time and all the fun.
Jim Graber

]]> By: island http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93317 island Wed, 06 Feb 2008 20:35:34 +0000 http://dorigo.wordpress.com/?p=1121#comment-93317 <i>I am writing from the lobby of a hotel in Lisbon, to say thank you and …. I do believe in</i> ghosts, I do believe in ghosts, I do, I do, I do, I do, I DO believe in... ghosts.... ;) I am writing from the lobby of a hotel in Lisbon, to say thank you and …. I do believe in ghosts, I do believe in ghosts, I do, I do, I do, I do, I DO believe in… ghosts…. ;)

]]> By: dorigo http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93299 dorigo Wed, 06 Feb 2008 13:56:50 +0000 http://dorigo.wordpress.com/?p=1121#comment-93299 Hello Jim, let me try to shed some light. The SM prefers a Higgs boson as light as it can be, since global fits to electroweak observables indicate a mass lower than 80 GeV; albeit with a large error bar. The direct lower limit stands at 114.4 (LEP II), so 120 GeV are distinctly better than 170 for SM. The same thing basically goes with MSSM theories: although there are many different possibilities, a Higgs above 135 GeV is even less wanted there. Again, the lighter, the better. As for Altarelli's plot, the two asymmetries point to different values of the Higgs mass, but these determinations are imprecise enough that one should not give them too much weight (there are in fact a dozen more - and it is the combination of all that indicates a low Higgs mass). The error bars in the plot, as far as I understand it, represent one-sigma coverages, but no guarantee exists that they are gaussian in nature. Cheers, Jim Hello Jim,

let me try to shed some light. The SM prefers a Higgs boson as light as it can be, since global fits to electroweak observables indicate a mass lower than 80 GeV; albeit with a large error bar. The direct lower limit stands at 114.4 (LEP II), so 120 GeV are distinctly better than 170 for SM.

The same thing basically goes with MSSM theories: although there are many different possibilities, a Higgs above 135 GeV is even less wanted there. Again, the lighter, the better.

As for Altarelli’s plot, the two asymmetries point to different values of the Higgs mass, but these determinations are imprecise enough that one should not give them too much weight (there are in fact a dozen more – and it is the combination of all that indicates a low Higgs mass). The error bars in the plot, as far as I understand it, represent one-sigma coverages, but no guarantee exists that they are gaussian in nature.

Cheers,
Jim

]]> By: Jim Graber http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93271 Jim Graber Tue, 05 Feb 2008 22:53:10 +0000 http://dorigo.wordpress.com/?p=1121#comment-93271 Higgs bosons for football fans: I want to cheer for my favorite Higgs mass prediction team! As I understand it, the standard model team wants a Higgs near 170 GeV. The MSSM team prefers 130 GeV or thereabouts. Looking at your graph two posts back from Altarelli’s talk, it looks like the Lepton asymmetry team wants an already excluded Higgs near 50 Gev, but the Hadron asymmetry data favors a heavy Higgs centered on 400 GeV, but stretching from 200 to 800 GeV. The world average seems happy up to about 150 GeV. Are those vertical error bars one sigma? And what is the relation to the previous Higgs mass charts you have posted? Actually, I cheer most for the LHC team to get that monster up and working. Best, Jim Graber Higgs bosons for football fans: I want to cheer for my favorite Higgs mass prediction team!
As I understand it, the standard model team wants a Higgs near 170 GeV.
The MSSM team prefers 130 GeV or thereabouts.
Looking at your graph two posts back from Altarelli’s talk, it looks like the Lepton asymmetry team wants an already excluded Higgs near 50 Gev, but the Hadron asymmetry data favors a heavy Higgs centered on 400 GeV, but stretching from 200 to 800 GeV. The world average seems happy up to about 150 GeV.
Are those vertical error bars one sigma?
And what is the relation to the previous Higgs mass charts you have posted?
Actually, I cheer most for the LHC team to get that monster up and working.
Best,
Jim Graber

]]> By: dorigo http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93160 dorigo Sun, 03 Feb 2008 21:28:18 +0000 http://dorigo.wordpress.com/?p=1121#comment-93160 Hi Kea, I am writing from the lobby of a hotel in Lisbon, to say thank you and .... I do believe in the Higgs, as I think you know. So it will indeed be interesting to see what is going to happen in the next few years. And well, if the LHC discovers nothing at all, it will become useful in other ways, such as sterilizing biological fertilizers or doing radiation therapy. And the caverns will be great for long-term storage. Cheers, T. Hi Kea,
I am writing from the lobby of a hotel in Lisbon, to say thank you and …. I do believe in the Higgs, as I think you know. So it will indeed be interesting to see what is going to happen in the next few years. And well, if the LHC discovers nothing at all, it will become useful in other ways, such as sterilizing biological fertilizers or doing radiation therapy. And the caverns will be great for long-term storage.

Cheers,
T.

]]> By: Kea http://dorigo.wordpress.com/2008/02/02/the-higgs-almost-excluded-at-160-gev/#comment-93084 Kea Sat, 02 Feb 2008 17:15:06 +0000 http://dorigo.wordpress.com/?p=1121#comment-93084 Congratulations! Now that's what I call teamwork. Don't worry - the LHC will probably be useful for looking at other stuff, which actually exists. Congratulations! Now that’s what I call teamwork. Don’t worry – the LHC will probably be useful for looking at other stuff, which actually exists.

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