[Hadstruct] [EXTERNAL] Re: GEVP

[Dutrieux, Herve]

Hmmm... so does it mean we have to turn to the 9 ops? I thought I heard you say it did not make a big difference compared to the 3 ops (for the ground state?).
Is there any chance anyone has an extraction of the Z factors and energies of this group of 4 excited states for the phased D0J0? Even if it does not come with the proper cfg by cfg statistical fluctuation, that would be an interesting quantity.

Cheers,
Hervé

________________________________
From: Hadstruct <hadstruct-bounces at jlab.org> on behalf of Orginos, Konstantinos via Hadstruct <hadstruct at jlab.org>
Sent: Wednesday, March 26, 2025 11:50:22 AM
To: Joseph Karpie via Hadstruct <hadstruct at jlab.org>
Subject: [Hadstruct] [EXTERNAL] GEVP

Hi everybody,

 I finally resolved the issue I had. My ordering of the operators caused me to compare the ground state principal correlator effective mass with that of a non-D0J0 ops. As a result the single operator was showing stronger excited state contamination. These are the plots that Herve saw sometime ago that got us excited about a possible improvement of our spectrum and matrix elements calculations at large momentum.

After fixing this problem my results are in line with Chris’ (and the rumored Robert’s results). The 3 operator GEVP gives no advantage over the single (D0J0) operator.

As I said on the call, given that the excited state nucleon spectrum has several  (N>2) nearly degenerate states close by a 3 operator basis is not expected to solve any problems.
This is the P=0,0,5 plot

Cheers,

K.

[cid:415c1b08-93ea-4ffc-93b8-1b31d8a92d76 at namprd05.prod.outlook.com]
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