[Psqateic] [EXTERNAL] Re: PSQ at EIC White Paper

Wed Aug 17 16:00:09 EDT 2022

Dear Volker:

        In a simple scheme, the forward matrix elements are \bar{C}_q = 
1/4 (quark condensate - <x>_q (\mu) M)
and \bar{C}_g = 1/4 (trace anomaly - <x>_g (\mu) M). The \pi N sigma 
term can be obtained from \pi N scattering, the strangeness
sigma term can be obtained from the lattice. The momentum fractions can 
be obtained from global fitting of DIS. How to obtain
the trace anomaly experimentally is a challenge. All of them can be and 
have been obtained in lattice calculations. The current
challenge for lattice is to calculate their form factors including the 
quark and glue parts of B (t) and C(t). In other words, all the
gravitational FFs including \bar{C}.

Best,
Keh-Fei

On 8/17/22 6:59 AM, Volker Burkert wrote:
> Dear Keh-Fei and Oleg,
>
> I like the idea to acknowledge the existence of additional terms that 
> cancel when summing quarks and gluons, but don't discuss them in any 
> detail.
> I have not seen a description of how \bar{C} can be measured in 
> experiment, either for quarks or for gluons, separately. If there are 
> such proposals we could refer to them in the WP.
>  Perhaps we could mention that \bar{C} may be computed in LQCD and 
> then used as correction to the EMT for quarks and gluons separately?
>
> Volker
>
> ------------------------------------------------------------------------
> *From:* teryaev <teryaev at jinr.ru>
> *Sent:* Wednesday, August 17, 2022 4:16 AM
> *To:* Keh-Fei Liu <liu at g.uky.edu>
> *Cc:* Volker Burkert <burkert at jlab.org>; psqateic at jlab.org 
> <psqateic at jlab.org>
> *Subject:* Re: [Psqateic] [EXTERNAL] Re: PSQ at EIC White Paper
> Dear Keh-Fei,
>
>
> You are completely right, there are terms cancelling when the when quark
> and gluon contributions are summed (due to equivalence principle, whose
> extension may be used to explain their smallness even separately),
> including C\bar ("proton cosmological constant")  together with
> anomalous gravitomagnetic moment, and often forgotten gravitoelectric
> dipole moment. violating also CP. Indeed, C \bar is crucially important
> when (separate) traces are calculated.
>
> Maybe in the text one can add after (6) something like "There are also
> terms cancelling
> in the sum of quark and gluons due to conservation laws and equivalence
> principle"?
>
> best regards,
> Oleg
>
> Keh-Fei Liu писал(а) 2022-08-13 08:56:
> > Dear Volker:
> >
> >        Now that we agree that there are \bar{C} terms in Eq. (6), take
> > the trace of the GFF in the rest frame, one
> > has the expression <T_{\mu\mu}> = [(A_q(0) + A_g(0)]M + Tr-Anomaly +
> > chiral condensate - [(A_q(0) + A_g(0)]M = Tr-Anomaly
> > +chiral condensate which is the correct expression. The last three
> > terms come from \bar{C} which is zero (for a good reason because
> > it is the stability condition). If one drops them first, one ends up
> > with the expression of [(A_q(0) + A_g(0)]M. Please explain why
> > it is acceptable and not wrong with an expression where the trace of
> > EMT does not contain trace anomaly. \bar{C} exists in many
> > publications in the literature, I don't understand the rationale for
> > dropping it in this document. It leads to (unintended) consequences.
> >
> > Best,
> > Keh-Fei
> >
> > On 8/12/22 4:07 PM, Volker Burkert wrote:
> >
> >> Dear Keh-Fei,
> >>
> >> * There is agreement for eq.(6) which deals with quark and gluon
> >> EMT separately, and the \bar{C} is needed (with opposite sign for q
> >> and g).
> >> * For eq.(19), which deals with the full EMT (quark + gluons} the
> >> \bar{C} terms should cancel out to zero, and the term \bar{C} should
> >> not appear.
> >>
> >> *
> >>
> >> *
> >> * Volker
> >>
> >> *
> >>
> >> -------------------------
> >>
> >> From: Keh-Fei Liu <liu at g.uky.edu>
> >> Sent: Friday, August 5, 2022 8:35 AM
> >> To: Volker Burkert <burkert at jlab.org>; psqateic-request at jlab.org
> >> <psqateic-request at jlab.org>
> >> Cc: Lorcé Cédric (M.) <cedric.lorce at polytechnique.edu>
> >> Subject: [EXTERNAL] Re: [Psqateic] PSQ at EIC White Paper
> >>
> >> Dear Volker and Latifa:
> >>
> >> Thank you for your tremendous effort in organizing this
> >> valuable whitepaper for the community.
> >>
> >> I now have a firm argument to show that one cannot drop
> >> the \bar{C} term in Eqs. (6) and (19). Take the
> >> forward FF of the trace T_{\mu\mu}, they give (A_q(0) + A_g(0))M.
> >> This is a trivial and meaningless result. It relates
> >> the matrix element of the trace to the mass via a sum rule of
> >> traceless matrix elements. It does not have the anomaly.
> >> Only when the \bar{C} is retained, do you get the correct expression
> >> with the anomaly. We should put the \bar{C} term back
> >> in these equations.
> >>
> >> Best,
> >> Keh-Fei
> >>
> >> On 8/3/22 4:33 PM, Volker Burkert wrote:
> >>
> >>> Dear Colleagues,
> >>>
> >>> We are sending you this email because you have registered to
> >>> participate in at least one of the workshops presented below,
> >>> which were held on December 15-16, 2020, March 17-19, 2021, and
> >>> July 19-23, 2021.
> >>>
> >>> One of the main goals of these workshops was to develop a white
> >>> paper focused on high-impact science requiring high integrated
> >>> luminosity at the low-to-medium center-of-mass energy of the U.S.
> >>> Electron-Ion Collider project.
> >>>
> >>> This white paper is ready to be submitted for publication. As a
> >>> participant in the workshop series, we invite you to become a
> >>> co-author of this white paper, which can be found at this link:
> >>>
> >>
> > 
> https://www.femtocenter.org/sites/default/files/docs/PSQ_EIC_White_Paper.pdf
> >>> [1]
> >>>
> >>> Please visit this link and review the scope and content of the
> >>> white paper. If you decide to co-author the WP, please send an
> >>> email to burkert at jlab.org no later than August 12.  You may also
> >>> suggest minor changes to the text, acknowledgements, and
> >>> references, or make comments that would improve the WP.
> >>>
> >>> We have an agreement with a journal to publish the paper and we
> >>> need to submit the final version by August 20.
> >>>
> >>> With best regards,
> >>>
> >>> Volker & Latifa
> >>>
> >>> 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_9794&d=DwIDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=Qy-CQv_msBooo8cd6Jy97FsQwD8soQkuCbKcwOzXyRURXIXufQPQRH2VFLMnTGww&s=S77fnwvL0qr9S0UjhFrOn1UKkpBtmyd0ngSd30jkvnM&e= 
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_9794&d=DwIDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=Qy-CQv_msBooo8cd6Jy97FsQwD8soQkuCbKcwOzXyRURXIXufQPQRH2VFLMnTGww&s=S77fnwvL0qr9S0UjhFrOn1UKkpBtmyd0ngSd30jkvnM&e=> 
> [2]
> >>>
> >>> 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_10677&d=DwIDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=Qy-CQv_msBooo8cd6Jy97FsQwD8soQkuCbKcwOzXyRURXIXufQPQRH2VFLMnTGww&s=fKbED_GbnFDO9bFXhGMzRrvCfcXJWfnRR1S8j0R6yhM&e= 
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_10677&d=DwIDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=Qy-CQv_msBooo8cd6Jy97FsQwD8soQkuCbKcwOzXyRURXIXufQPQRH2VFLMnTGww&s=fKbED_GbnFDO9bFXhGMzRrvCfcXJWfnRR1S8j0R6yhM&e=> 
> [3]
> >>>
> >>> 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_11669&d=DwIDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=Qy-CQv_msBooo8cd6Jy97FsQwD8soQkuCbKcwOzXyRURXIXufQPQRH2VFLMnTGww&s=Qcy4YcgzWFq0QuKBEPSZwhN7LZBCAp-YbjHSGZmhWH8&e= 
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_11669&d=DwIDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=Qy-CQv_msBooo8cd6Jy97FsQwD8soQkuCbKcwOzXyRURXIXufQPQRH2VFLMnTGww&s=Qcy4YcgzWFq0QuKBEPSZwhN7LZBCAp-YbjHSGZmhWH8&e=> 
> [4]
> >>>
> >>> _______________________________________________
> >>> Psqateic mailing list
> >>> Psqateic at jlab.org
> >>> https://mailman.jlab.org/mailman/listinfo/psqateic
> >
> >
> >
> > Links:
> > ------
> > [1]
> > 
> https://www.femtocenter.org/sites/default/files/docs/PSQ_EIC_White_Paper.pdf
> > [2]
> > 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_9794&d=DwMDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=5AYW9vwxxp8DN9axYcgThaO2tDVhNhrtj-XHvMm22kfS_MbCzGceMTTjt26SJakY&s=4daDQQx1-C0DPsG0iFTkbWjsPATQb5ZddY_N9OGquj0&e= 
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_9794&d=DwMDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=5AYW9vwxxp8DN9axYcgThaO2tDVhNhrtj-XHvMm22kfS_MbCzGceMTTjt26SJakY&s=4daDQQx1-C0DPsG0iFTkbWjsPATQb5ZddY_N9OGquj0&e=>
> > [3]
> > 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_10677&d=DwMDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=5AYW9vwxxp8DN9axYcgThaO2tDVhNhrtj-XHvMm22kfS_MbCzGceMTTjt26SJakY&s=vIOR4EUCQxbO8iay3K1a8zheeXLc26lrKytTPA4AF_U&e= 
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_10677&d=DwMDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=5AYW9vwxxp8DN9axYcgThaO2tDVhNhrtj-XHvMm22kfS_MbCzGceMTTjt26SJakY&s=vIOR4EUCQxbO8iay3K1a8zheeXLc26lrKytTPA4AF_U&e=>
> > [4]
> > 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_11669&d=DwMDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=5AYW9vwxxp8DN9axYcgThaO2tDVhNhrtj-XHvMm22kfS_MbCzGceMTTjt26SJakY&s=ULJyvLIlwTDZWjvQsqoes6fwCcIVQE67gO8XWJup3aI&e= 
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_11669&d=DwMDaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=vVqGQabj76hiyFv-SdFNhS9JnbDxELkn2szNoXMYQyo&m=5AYW9vwxxp8DN9axYcgThaO2tDVhNhrtj-XHvMm22kfS_MbCzGceMTTjt26SJakY&s=ULJyvLIlwTDZWjvQsqoes6fwCcIVQE67gO8XWJup3aI&e=>
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