Dear Patrick,

I also had a closer look at the paper. I have only a few issues:

l. 19: a la Niels I think having a figure here is indispensable. Because seeing why b->edubar and b->duubar should interfere is by no means obvious, even to fellow particle physicists.

l29-33: the link from T-violating to CP-violating observables is made without even mentioning the CPT theorem! That is of course VERY sloppy! What is defined in are really the T-odd and then P-odd or P-even observables. You need to ASSUME CPT-invariance to make that into a CP-violating observable.

l.36-39: there is such a thing as a strong-CP phase, which is connected to the so-called theta-bar term. I doubt it that this is what is meant here with “strong” phase. The whole argument here requires too much thought. Can it be made simpler so that it can be made clearer what the point actually is?

Greetings,

Gerco

On 21 Jul 2016, at 14:48, Niels Tuning h71@nikhef.nl wrote:

Hi Patrick,

Thanks for reminding me to read this historical paper. Please find my comments below.

Cheers, Niels

---

General

• Instead of "-CP-", I would write out "CP violation".
• Example diagrams of the interfering b->udu and b->duu amplitudes are

indispensable, for a Nature Physics paper aiming at a wider circle than flavour physicists.

Other

L.7 "virtual W boson with couplings whose phases can" -> "virtual W boson where the phases of the couplings can"

L.20-21 "CPV could arise from the interference of two amplitudes mainly due to the large phase of the CKM element Vub ..." [Strictly speaking this is not true. Other phase conventions have a vanishing phase for Vub. How about this: ] "CPV could arise from the interference of two amplitudes mainly due to the large phase difference if one of the amplitudes involves the CKM element Vub ..."

L.31 [Why does the T-operator get a hat, and the P-operator not?]

L.32 [Please could you insert the phrase time-reversal somewhere? Maybe here:] "where T is the operator... three-vectors [16,17]." -> "where T is the operator... three-vectors, also known as the time-reversal operator [16,17]."

L.45 ["localised CPV" sounds jargon. How about: ] "... to enhance sensitivity to CPV in specific parts of the phase space."

L.50 [Could you add a reference to the LHCb measurement of BR(Lb->Lcpi), \cite{LHCb-PAPER-2014-004}, which shows that these are indeed the most abundant decays? (And the reference gives also more details on the relative Lb production.)]

L.121 [The phrasing of the bins of scheme B, using the n,(n-1) interval, is complicated. How about simply: ] "Scheme B has 10 equidistant bins in |Phi|."

Fig.2 [The legend and Chi2 of Figs.c) and d) are smaller than the ones in a) and b).]

L.147. [My Chi2 calculator shows that Chi2/ndf=30.5/10 corresponds to a p-value of 7.1 x 10^-4 ? (and 21.1/12 becomes p=4.89 x 10^-2 ?]

---

On Thu, 21 Jul 2016, Patrick Koppenburg wrote:

...

Hi all, I was expecting no replies. Please read the paper and send me your comments. There's likely to be some noise about it, so you may get asked questions by your non-LHCb colleagues. The best way to be informed about (and influence) the content is to read it now. The next paper assigned to us will be that to be approved today https://indico.cern.ch/event/558480/ . It's tt, W+bb and W+cc cross-sections (to go to paper) but it will be followed by a CONF on Higgs->bb and Higgs->cc. I understand this will also be assigned to us. Cheers, Patrick On 07/18/2016 04:03 PM, Patrick Koppenburg wrote: Dear all,

 There's an important paper for us: The first evidence of CP violation in baryons. It would also be our 2nd paper going to Nature Physics.

 Anyone volunteering to collect comments?

 Thanks

 Patrick

 -------- Forwarded Message --------
 Subject:
 First circulation of publication draft for PAPER-2016-030, Probing matter-antimatter asymmetries in $\Lambda^0_b$-baryon decays
 Date:
 Mon, 18 Jul 2016 15:32:41 +0200
 From:
 Michael Schmelling <Michael.Schmelling@mpi-hd.mpg.de>
 To:
 LHCb General mailing list <lhcb-general@cern.ch>

Dear Colleagues, A draft paper is available for your comments: Team leaders, please verify the author list and check for reading obligations of your group! Note that in view of ICHEP the circulation has been shortened from 2 weeks to 10 working days. Title : Probing matter-antimatter asymmetries in $\Lambda^0_b$-baryon decays Journal : Nature Physics Contact authors : Jinlin_Fu, Nicola_Neri, Maurizio_Martinelli, Andrea_Merli Reviewers : Steve_Playfer (chair), Mike_Sokoloff EB reviewer : Mat_Charles EB readers : Michael_Schmelling, Simon_Eidelman Analysis note : ANA-2014-077 Deadline : 29-Jul-2016 e-group : lhcb-paper-2016-030-reviewers Link : https://cds.cern.ch/record/2199884 Authors : LHCb Twiki : https://twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/LambdabTophhh The following institutes are requested to make institutional comments: NIKHEF__Amsterdam__The_Netherlands Edinburgh__United_Kingdom UFRJ__Rio_de_Janeiro__Brazil Bucharest-Magurele__Romania Padova__Italy PNPI__Gatchina__Russia Please send any comments via the CDS system. It is the responsibility of the contact authors to provide replies to all comments made. Subsequent modifications to the draft will be made in consultation with the reviewers and during the EB reading. Following this, there will be a final meeting of the editorial board, with contact authors and reviewers present, when final decisions will be made. As the last step, the collaboration will be given a final opportunity to comment during a “silent approval” period. You can find all paper and conference report drafts open for comments via the EB web-page, by clicking on Current Drafts: http://lhcb.web.cern.ch/lhcb/lhcb_page/collaboration/organization/editorial_... Best regards, Michael -- Michael Schmelling, MPI for Nuclear Physics Phone:+49-6221-516-511 Fax:+49-6221-516-603

---

Bfys-physics mailing list Bfys-physics@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics

- Gerco

Dr. C.J.G. Onderwater Van Swinderen Institute University of Groningen Nijenborgh 4 NL-9747 AG Groningen the Netherlands Tel. +31(0)50-3633557 / 8774

Dear all,

On occasion I may be slow, but this beats all. I have no clue where this one got stuck ...

Greetings,

-- Gerco

Dr. C.J.G. Onderwater van Swinderen Institute University of Groningen Nijenborgh 4 NL 9747 AG Groningen Netherlands Tel. +31(0)50-3633557 Fax. +31(0)50-3634003

On 22 jul. 2016, at 17:16, Gerco Onderwater gerco.onderwater@gmail.com wrote:

Dear Patrick,

I also had a closer look at the paper. I have only a few issues:

l. 19: a la Niels I think having a figure here is indispensable. Because seeing why b->edubar and b->duubar should interfere is by no means obvious, even to fellow particle physicists.

l29-33: the link from T-violating to CP-violating observables is made without even mentioning the CPT theorem! That is of course VERY sloppy! What is defined in are really the T-odd and then P-odd or P-even observables. You need to ASSUME CPT-invariance to make that into a CP-violating observable.

l.36-39: there is such a thing as a strong-CP phase, which is connected to the so-called theta-bar term. I doubt it that this is what is meant here with “strong” phase. The whole argument here requires too much thought. Can it be made simpler so that it can be made clearer what the point actually is?

Greetings,

Gerco

...

On 21 Jul 2016, at 14:48, Niels Tuning h71@nikhef.nl wrote:

Hi Patrick,

Thanks for reminding me to read this historical paper. Please find my comments below.

Cheers, Niels

---

General

• Instead of "-CP-", I would write out "CP violation".
• Example diagrams of the interfering b->udu and b->duu amplitudes are

indispensable, for a Nature Physics paper aiming at a wider circle than flavour physicists.

Other

L.7 "virtual W boson with couplings whose phases can" -> "virtual W boson where the phases of the couplings can"

L.20-21 "CPV could arise from the interference of two amplitudes mainly due to the large phase of the CKM element Vub ..." [Strictly speaking this is not true. Other phase conventions have a vanishing phase for Vub. How about this: ] "CPV could arise from the interference of two amplitudes mainly due to the large phase difference if one of the amplitudes involves the CKM element Vub ..."

L.31 [Why does the T-operator get a hat, and the P-operator not?]

L.32 [Please could you insert the phrase time-reversal somewhere? Maybe here:] "where T is the operator... three-vectors [16,17]." -> "where T is the operator... three-vectors, also known as the time-reversal operator [16,17]."

L.45 ["localised CPV" sounds jargon. How about: ] "... to enhance sensitivity to CPV in specific parts of the phase space."

L.50 [Could you add a reference to the LHCb measurement of BR(Lb->Lcpi), \cite{LHCb-PAPER-2014-004}, which shows that these are indeed the most abundant decays? (And the reference gives also more details on the relative Lb production.)]

L.121 [The phrasing of the bins of scheme B, using the n,(n-1) interval, is complicated. How about simply: ] "Scheme B has 10 equidistant bins in |Phi|."

Fig.2 [The legend and Chi2 of Figs.c) and d) are smaller than the ones in a) and b).]

L.147. [My Chi2 calculator shows that Chi2/ndf=30.5/10 corresponds to a p-value of 7.1 x 10^-4 ? (and 21.1/12 becomes p=4.89 x 10^-2 ?]

---

...

On Thu, 21 Jul 2016, Patrick Koppenburg wrote:

Hi all, I was expecting no replies. Please read the paper and send me your comments. There's likely to be some noise about it, so you may get asked questions by your non-LHCb colleagues. The best way to be informed about (and influence) the content is to read it now. The next paper assigned to us will be that to be approved today https://indico.cern.ch/event/558480/ . It's tt, W+bb and W+cc cross-sections (to go to paper) but it will be followed by a CONF on Higgs->bb and Higgs->cc. I understand this will also be assigned to us. Cheers, Patrick On 07/18/2016 04:03 PM, Patrick Koppenburg wrote: Dear all,

 There's an important paper for us: The first evidence of CP violation in baryons. It would also be our 2nd paper going to Nature Physics.

 Anyone volunteering to collect comments?

 Thanks

 Patrick

 -------- Forwarded Message --------
 Subject:
 First circulation of publication draft for PAPER-2016-030, Probing matter-antimatter asymmetries in $\Lambda^0_b$-baryon decays
 Date:
 Mon, 18 Jul 2016 15:32:41 +0200
 From:
 Michael Schmelling <Michael.Schmelling@mpi-hd.mpg.de>
 To:
 LHCb General mailing list <lhcb-general@cern.ch>

Dear Colleagues, A draft paper is available for your comments: Team leaders, please verify the author list and check for reading obligations of your group! Note that in view of ICHEP the circulation has been shortened from 2 weeks to 10 working days. Title : Probing matter-antimatter asymmetries in $\Lambda^0_b$-baryon decays Journal : Nature Physics Contact authors : Jinlin_Fu, Nicola_Neri, Maurizio_Martinelli, Andrea_Merli Reviewers : Steve_Playfer (chair), Mike_Sokoloff EB reviewer : Mat_Charles EB readers : Michael_Schmelling, Simon_Eidelman Analysis note : ANA-2014-077 Deadline : 29-Jul-2016 e-group : lhcb-paper-2016-030-reviewers Link : https://cds.cern.ch/record/2199884 Authors : LHCb Twiki : https://twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/LambdabTophhh The following institutes are requested to make institutional comments: NIKHEF__Amsterdam__The_Netherlands Edinburgh__United_Kingdom UFRJ__Rio_de_Janeiro__Brazil Bucharest-Magurele__Romania Padova__Italy PNPI__Gatchina__Russia Please send any comments via the CDS system. It is the responsibility of the contact authors to provide replies to all comments made. Subsequent modifications to the draft will be made in consultation with the reviewers and during the EB reading. Following this, there will be a final meeting of the editorial board, with contact authors and reviewers present, when final decisions will be made. As the last step, the collaboration will be given a final opportunity to comment during a “silent approval” period. You can find all paper and conference report drafts open for comments via the EB web-page, by clicking on Current Drafts: http://lhcb.web.cern.ch/lhcb/lhcb_page/collaboration/organization/editorial_... Best regards, Michael -- Michael Schmelling, MPI for Nuclear Physics Phone:+49-6221-516-511 Fax:+49-6221-516-603

---

Bfys-physics mailing list Bfys-physics@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics

• Gerco

Dr. C.J.G. Onderwater Van Swinderen Institute University of Groningen Nijenborgh 4 NL-9747 AG Groningen the Netherlands Tel. +31(0)50-3633557 / 8774

---

Bfys-physics mailing list Bfys-physics@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics

Hi, here are my comments to the baryon asymmetry paper.

First of all a great result that indeed deserves attention.

However, perhaps it is due to the fact that I have been on holidays, but I find the language in the paper far too technical for Nature. I think it is not written with a reader of Nature in mind. It is often small things that we take for granted in eg a PRL paper, but that should be done a bit more carefully for nature. eg: "the sum of two Crystal Ball functions[ref]" is not a format of language I would use in Nature.

clearly some illustations would help, eg Feynman diagrams and the event planes defining the angle Phi and the triple products.

As usual we describe the selection process, the precise definitions of observables and all details, but we could also chose to describe things one abstraction level higher and leave out some details that matter less for nature. And add some explanations of the ideas behind.

Examples: - line 32 eq (3): it is not a priory clear why A_T + A_T-bar is P-violating,while A_T - A_T-bar is CP violating. I find it very difficult to "see through" the triple product definitions and interpret that. Perhaps this can be explained a bit more.

- line 35: I also doubt that Nature readers appreciate the rich resonant substructure of the three particle phase space.

- line 38: Same comment for the "nonvanishing difference in CP invariant phase".

- line 45: what are "localised CPV effects". (Dalitz phase space is behind)

- lines 119 - 125 are "dense" to read.

On the two binning schemes: Scheme A is mainly resonance contributions while scheme B exploits interferences. So what? What is the idea behind? p-value A = 4.9 x 10^-2 (2 sigma) p-value B = 7.1 x 10^-4 (3.4 sigma) --> Do we expect such a behaviour? Yes, becaus of interferences, but no text is spend on this.

Why is the product of the two p-values of the binning schemes the best thing to look at (3.3 sigma) and not just scheme B? And forget abut scheme A?

I realize that I would have a hard time "explaining" this people to outsiders...

cheers, - Marcel

On 21 July 2016 at 03:35, Patrick Koppenburg Patrick.Koppenburg@cern.ch wrote:

Hi all,

I was expecting no replies. Please read the paper and send me your comments. There's likely to be some noise about it, so you may get asked questions by your non-LHCb colleagues. The best way to be informed about (and influence) the content is to read it now.

The next paper assigned to us will be that to be approved today https://indico.cern.ch/event/558480/ . It's tt, W+bb and W+cc cross-sections (to go to paper) but it will be followed by a CONF on Higgs->bb and Higgs->cc. I understand this will also be assigned to us.

Cheers,

Patrick

On 07/18/2016 04:03 PM, Patrick Koppenburg wrote:

Dear all,

There's an important paper for us: The first evidence of CP violation in baryons. It would also be our 2nd paper going to Nature Physics.

Anyone volunteering to collect comments?

Thanks

Patrick

-------- Forwarded Message -------- Subject: First circulation of publication draft for PAPER-2016-030, Probing matter-antimatter asymmetries in $\Lambda^0_b$-baryon decays Date: Mon, 18 Jul 2016 15:32:41 +0200 From: Michael Schmelling Michael.Schmelling@mpi-hd.mpg.de Michael.Schmelling@mpi-hd.mpg.de To: LHCb General mailing list lhcb-general@cern.ch lhcb-general@cern.ch

Dear Colleagues,

A draft paper is available for your comments:

Team leaders, please verify the author list and check for reading obligations of your group!

Note that in view of ICHEP the circulation has been shortened from 2 weeks to 10 working days.

Title : Probing matter-antimatter asymmetries in $\Lambda^0_b$-baryon decays

Journal : Nature Physics Contact authors : Jinlin_Fu, Nicola_Neri, Maurizio_Martinelli, Andrea_Merli Reviewers : Steve_Playfer (chair), Mike_Sokoloff EB reviewer : Mat_Charles EB readers : Michael_Schmelling, Simon_Eidelman Analysis note : ANA-2014-077 Deadline : 29-Jul-2016 e-group : lhcb-paper-2016-030-reviewers Link : https://cds.cern.ch/record/2199884 Authors : LHCb Twiki : https://twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/LambdabTophhh

The following institutes are requested to make institutional comments: NIKHEF__Amsterdam__The_Netherlands Edinburgh__United_Kingdom UFRJ__Rio_de_Janeiro__Brazil Bucharest-Magurele__Romania Padova__Italy PNPI__Gatchina__Russia

Please send any comments via the CDS system. It is the responsibility of the contact authors to provide replies to all comments made. Subsequent modifications to the draft will be made in consultation with the reviewers and during the EB reading. Following this, there will be a final meeting of the editorial board, with contact authors and reviewers present, when final decisions will be made. As the last step, the collaboration will be given a final opportunity to comment during a “silent approval” period.

You can find all paper and conference report drafts open for comments via the EB web-page, by clicking on Current Drafts: http://lhcb.web.cern.ch/lhcb/lhcb_page/collaboration/organization/editorial_...

Best regards, Michael

-- Michael Schmelling, MPI for Nuclear Physics Phone:+49-6221-516-511 Fax:+49-6221-516-603

--

Patrick Koppenburg Nikhef, Amsterdam http://www.koppenburg.org/address.html

---

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