Polarised data

[enocera]

This is a list of inclusive DIS data to be implemented and included in a fit.

Experiment	Reference	hepdata
EMC	Nucl.Phys. B328 (1989) 1	https://hepdata.net/record/ins280143
SMC	Phys.Rev. D58 (1998) 112001	https://hepdata.net/record/ins471981
SMClowx	Phys.Rev. D60 (1999) 072004	n/a (from paper)
E142	Phys.Rev. D54 (1996) 6620	https://hepdata.net/record/ins424108
E143	Phys.Rev. D58(1998)112003	https://hepdata.net/record/ins467140
E154	Phys.Rev.Lett. 79 (1997) 26	https://hepdata.net/record/ins443170
	Phys.Lett. B405 (1997) 180	https://hepdata.net/record/ins443186
E155	Phys.Lett. B493 (2000) 19	https://hepdata.net/record/ins530798
COMPASS_P	Phys.Lett. B690 (2010) 466	https://hepdata.net/record/ins843494
COMPASS_D	Phys.Lett. B647 (2007) 8	https://hepdata.net/record/ins726688
COMPASS_P15	Phys.Lett. B753 (2016) 18	https://hepdata.net/record/ins1357198
COMPASS_D15	Phys.Lett. B769 (2017) 34	https://hepdata.net/record/ins1501480
HERMES97	Phys.Lett.B404(1997)383	https://www.hepdata.net/record/ins440904
HERMES	Phys.Rev. D75 (2007) 012007	https://hepdata.net/record/ins726689
JLAB-E06-014	Phys.Lett. B744 (2015) 309	n/a (from paper)
JLAB-E97-103	Phys.Rev.Lett. 95 (2005) 142002	https://hepdata.net/record/ins684137
JLAB-E99-117	Phys.Rev. C70 (2004) 065207	https://hepdata.net/record/ins650244
JLAB-EG1-DVCS	Phys.Rev. C90 (2014) 025212	https://hepdata.net/record/ins1292133
JLAB-E93-009	Phys.Lett. B641 (2006) 11	https://hepdata.net/record/ins717523

Whenever data are available for both the virtual photon asymmetry (A₁) and the longitudinal structure function (g₁), they should be implemented both. If the longitudinal spin asymmetry is provided (A_||), it should be implemented as well. The transverse spin asymmetry (A_ᅩ and/or A₂) and the transverse structure function (g₂) should not be implemented. As far as I recollect, the full experimental covariance matrix is provided only for the HERMES experiment, but htis must be checked.

[tgiani]

Great, thanks!

[juanrojochacon]

Just for my curiosity @enocera @tgiani are you guys trying to resurrect the NNPDFpol fits with the new code? That would be really great! Or perhaps this is an exercise related to the lattice workshop whitepaper?

[enocera]

Both things.

[juanrojochacon]

Thanks for the confirmation, sounds very interesting.

[juanrojochacon]

Indeed for the polarised case we know that lattice calculations should have an impact more easily than in the better known unpolarised case

[tgiani]

I ve implemented COMPASS_P and COMPASS_P15.
They are in the branch called "polarized", all the data in the table above are going to be implemented in this same branch.
Some doubts:

1. On hepdata the data are delivered both as (x,Q^2) bins and in x bins averaged over Q^2. I ve implemented the first case, (x,Q^2) bins, is it fine?
2. For these data as far as I can tell it is provided just one total systematic, so I m implementing it as UNCORR

[tgiani]

Concerning point 1) the answer is probably "no" (at least looking at the old DIS fit paper, where I can see only 15 points for COMPASS, against the 44 I have from the table with (x,Q^2) bins)

[enocera]

1. On hepdata the data are delivered both as (x,Q^2) bins and in x bins averaged over Q^2. I ve implemented the first case, (x,Q^2) bins, is it fine?

Yes, please forget about the other format.

2. For these data as far as I can tell it is provided just one total systematic, so I m implementing it as UNCORR

Yes. As you'll notice, 95% of the data comes with one uncorrelated total systematic.

[tgiani]

another question: when implementing a DIS experiment in buildmaster, according to the documentation the third kinematic variable should be y whose textbook definition is
y= (p\cdot q) / (k\cdot p) where p, q, k are the 4 momentum of the target, of the intermediate vector boson and of the incoming particle respectively. Then in the rest frame of the target one should have
y = Q^2/(2x m k_0) whereQ^2 is the virtuality of the intermediate vector boson, x is the bjorken variable, m is the target mass and k_0 is the energy of the incoming beam. Is this what I m supposed to assign to kin[3]?

[enocera]

Yes, it is. As far as I can tell kin[3] (in DIS) is used for plotting purposes only, it's not crucial e.g. for FK table generation or elsewhere in the fit.

[tgiani]

Also, regarding JLAB-E93-009 on hep data there are 306 tables, with data corresponding to g1 and A1 for proton and deuteron targets, with beam energies of 1.6 and 5.7 GeV, given at a lot of different values of the final state invariant mass W (up to 3 GeV). Again in total there are 306 tables..which ones should I be looking at? Just the ones with the higher values of W?

[enocera]

You can ignore all the tables with Q^2<1 GeV^2 and with W<2 GeV. But please implement both p and d (and both g1 and F1).

[tgiani]

Ok, so just to be sure I m getting this right:
as for JLAB-E93-009 there are data for A1 and the ratio g1/A1 for both proton and deuteron targets. There are 306 tables in total, each of them given at a fixed value of W.
For p target, the tables with W>2GeV and Q2>1GeV are Tabs. 46, ..., 67 for a total od 22 tables, while for deut target we have Tabs. 227, ..., 296 for a total of 80 tables. Can you please confirm you want me to implement the data from this 80 + 22 tables?
Also, how should I do the implementation? Should I consider a single dataset for all the proton tables (so a single dataset containing 22 different W values) and another one for all the deut data (so another single dataset containing 80 different W values)? Or should I implement 80 + 22 different dataset, each one with a sopecific W value? Thanks

[enocera]

Ok, so just to be sure I m getting this right:
as for JLAB-E93-009 there are data for A1 and the ratio g1/A1

isn't it the ratio g1/F1?

for both proton and deuteron targets. There are 306 tables in total, each of them given at a fixed
value of W.
For p target, the tables with W>2GeV and Q2>1GeV are Tabs. 46, ..., 67 for a total od 22 tables, while for deut target we have Tabs. 227, ..., 296 for a total of 80 tables. Can you please confirm you want me to implement the data from this 80 + 22 tables?

Yes. Most of these data will be possibly removed by our default kinematic cuts; however, since we are revisiting everything, it'd be better to have all these tables implemented for future studies, when we might want to investigate the dependence upon the W cut.

Also, how should I do the implementation? Should I consider a single dataset for all the proton tables (so a single dataset containing 22 different W values) and another one for all the deut data (so another single dataset containing 80 different W values)? Or should I implement 80 + 22 different dataset, each one with a sopecific W value? Thanks

You should just have two datasets (one for the proton and one for the deuteron).