bfys-physics

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520 discussions

[Bfys-physics] Fwd: [Theory-wide] Nikhef theory seminar -- Thursday 22nd @ 2pm
by Robert Fleischer 21 Mar '12

21 Mar '12

Dear Colleagues, please find appended below a seminar announcement. Best regards, Robert Begin forwarded message: > From: Damien George <dpgeorge(a)nikhef.nl> > Date: March 21, 2012 12:02:29 PM GMT+01:00 > To: theory-wide(a)nikhef.nl > Subject: [Theory-wide] Nikhef theory seminar -- Thursday 22nd @ 2pm > > Dear all, > > Tomorrow we have a theory seminar at 2pm in room H220 (note unusual > location). The speaker is Alexander Lenz from CERN, who will talk about > the latest results from LHCb. See below for details. > > Regards, > Damien George and Mert Aybat. > > ---- > > Date/place: Thursday 22nd March, 2pm, H220 > Speaker: Alexander Lenz (CERN) > Title: B mixing - What did we learn from LHCb in 2011? > > I will review the current status of standard model predictions for > B-mixing in the light of the most recent results of LHCb and TeVatron > presented at Moriond 2012. Conseuqences for new physics searches will > also be discussed. > _______________________________________________ > Theory-wide mailing list > Theory-wide(a)nikhef.nl > https://mailman.nikhef.nl/mailman/listinfo/theory-wide

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[Bfys-physics] Seminar of Vava on Monday
by Marcel Merk 21 Mar '12

21 Mar '12

Dear friends, On Monday (26/3) Vladimir Gligorov ("Vava") will be at Nikhef and give a talk at 14h00 on the physics of the decay Bs->Ds+ Ds-. The location will follow later. I hope you can come to the presentation. cheers, - Marcel

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[Bfys-physics] collected comments for the Bs->phi phi analysis
by Roel Aaij 08 Mar '12

08 Mar '12

Dear All, We have collected the comments we received from everybody and have listed them below. Please check that your comments are included and that you are happy with the chosen wording. Best regards, Roel & Tjeerd General comments: - It seems that the time-dependent equations in Eq. (4) are not relevant. - We think that it would be much more informative to present the integrals of Eq. (5) including non-zero phi_s and the production asymmetry, but excluding detector dependent effects. Those should be easy to derive. Then it seems important to indicate early that the time integrated equations are only valid if you ignore the experimental acceptances and that ignoring those actually leads to non-negligible systematic uncertainties. Did you in the analysis correct these equations for the decay time acceptance? We think that it would be very informative to show how equation 5 changes if you introduce a lower cut off in the lifetime. In your analysis, it seems that this lower cut off is about 1ps, very large compared to the lifetimes. Could you explain how the described optimization procedure resulted in such a large cut? - Performing the time integration before folding in lifetime biasing effects, like cuts and the lifetime acceptance, is not correct. The lifetime component corresponding to A_0 and A_|| is tau_l, while for A_perp this is tau_h. Since a time acceptance has a different effect on these two components, it should be folded in before the integration over time is performed. This holds for both the lifetime bias introduced by the tight FD chi^2 cut and the detector time acceptance. Comments in detail: Abstract: Why do we quote three amplitudes squared if the sum is equal to unity? Like in the quoted B factory papers we can limit ourself to the first two. Lines 2-3: - FCNC is not used further and the abbreviation is superfluous. - A suggestion to replace "Studies ... tests" by "Triple product asymmetry studies in this decay mode provide a powerful test". Line 12: - Remove typing error 'of' in "V-A of structure". Consider "vector minus axial vector (V$-$A) structure", as we mention also vectors and pseudo scalars. Line 14: - Replace "roughly equal longitudinal and transverse components" by Longitudinal fractions of $f_L = |A_0|^2 \approx 0.5$ ". Line 17-19: - Replace 'predictions' by 'calculations' and "give ... 70%" by "allow for $f_L$ in the range of 0.4-0.7 [2,3]". Fig. 1, caption: - Replace "helicity frame" by "center-of-mass frame" and 'mode' to "decay mode". Lines 22-31: - I suppose that a reference here in stead of Eq.~(4) will be sufficient; we only consider the time integrated results. Lines 32-34: - Replace "If as in this Letter ... integrate to" by "In an ideal situation where we can integrate over the full time range with CP violating phase $\phi_s=0$ and an equal number of B0s and Bbar0s mesons are produced, the time integrals of the functions $K_i(t)$ are:" (Avoid "in this Letter". This is not the analysis that is integrated.) - It would be much more informative to present the integrals including non-zero phi_s and the production asymmetry, but excluding detector dependent effects. Those should be easy to derive. Lines 40-47: - The '$\pm$' sign in the definition of $V$ is not correct, because $\Phi$ is already negative or positive by definition in Eq.(6). - A rearrangement of the text arround Eq. (6) and the equation itself is suggested in the following changes: - Replace "due either to ... is violated" by "due either to final state interactions or to T violation, which with conservation of CPT also implies CP violation." - Move sentence "This approach ... is required" to line 47. - Replace "There are two ... triple products" by "There are two observables, triple products of unit vectors," and then start the equation directly with on the left sides in addition: "V =" and "U =". - Replace "These are proportional ..." by "From Fig. 1 it can be deduced that $V$ is positive if $cos\theta_1 \cos\theta_2 \gt 0$ and zero or negative otherwise. The T-odd variables $V$ and $U$ are proportional ..." It could help to draw $n_{V1}$, $n_{V2}$ and $p_{V1}$ vectors in Fig. 1 on the outer sides of the two decay planes. Lines 55-56: - If sample size the number should be larger than 801. If signal yiels they should have estimated uncertainties. - Avoid "In this Letter". Line 70: Remove "consisting of ... GEM)". (It is not clear if 'consisting' applies also to 'Hadron' and if 'distinguishes' applies to only 'Muon'.) Line 72: Add '(L0)' after 'triggering'. (L0 is used later without definition.) Line 76: Add "of various selection lines". (Lines are used later without description.) Line 83: We don't quite understand why you need to mention "s-plot" here. If you do, you need to mention what was used as separating variable. (In the end, it is just a fancy sideband subtraction. You wouldn't quote that you use sideband subtraction without explicitly mentioning which sideband.) Note that the optimization using splot explicitly relies on the fact that the signal and background shapes are independent of your cuts. For the background B mass shape that is almost guaranteed not to be the case. (For example, the background B mass slope will depend on pT cuts, and even on vertex chi2 cuts.) We wonder how you took this into account in the optimization. Line 87: Remove the sentence about the KL distance like in the table. This is just an artefact of our track finding. Table 1: - Replace "Cut" by "Selection variable". - Are the IP chi2 cut and FD chi2 cut per dof? What is the number of dofs for the FD cut? (if it is 3, that this quantity is different from what most people outside lhcb think that it is.) Lines 110-112: - Same remark as above about using 's-plot technique': you always should mention the separating variable. - Typing error "Fig. 3". - What function did you use for the two-body phase space component? How did you take the experimental resolution on the KK invariant mass into account? Line 128: - You say that you use the measurements of Gs and DGs from a different source, including their errors. However, doesn't one expect that the dominating effect is the decay time acceptance? Fig. 3, caption: - Remove spurious "is applied". - Add the separating variable used for making the s-plot. Line 142: - We are actually a bit surprised that the effect of ignoring the decay time acceptance is so small. Looking at your analysis note, the lifetime acceptance effectively introduces a cut off of about 1 ps, large compared to tau_l and tau_H. Why don't you see this directly in the amplitudes? Is it because dG/G is small and the sum of the amplitudes is normalized to 1? The analysis note is very brief here: It shows the final numbers but not actually the toy distributions. Fig. 4: - Are the fit projections corrected for the angular acceptance? This seems impossible to do with just the acceptance weights. If not, then that should be mentioned in the caption. Table 3: - Replace the '-' with '0.000'. (A dash makes it seem like you didn't compute it.) - We don't understand why you quote separate results and systematic uncertainties for A_par2. You require the sum of the 3 amplitudes to be unity. So, anything that affects two amplitudes, will also affect the 3rd. It seems better to skip A_par2 completely. For example, given equation 5, it seems hard to understand why A_par2 and A_02 have different sensitivity to the lifetime acceptance: they have roughly the same size, they appear with the same lifetime in your observables, so why do they not have the same sensitivity to the acceptance? Line 152: - Remove "This has been checked to be valid in simulation studies". Or explain why you would worry about this. Line 168: Remove sentence "Measurements ... A_0|^2$". The results do not differ so much from ~0.5 with the large spread the other values have. Lines 169-170: - Replace "in agreement with that" by "almost equal to that". - Replace "also in reasonable agreement" by "in agreement". 'Also' is not correct and 'reasonable' is not subjective. Line 175: - Replace 'hypothesis of no CP violation" by "hypothesis of CP conservation". -- Roel Aaij Nikhef, office N250 Tel: +31 (0)20 592 2069 Sciencepark 105 Mob: +31 (0)641 370 757 1098 XG Amsterdam +41 (0)799 272 882

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[Bfys-physics] LHCB-PAPER-2011-030-001-COMMENT-012
by Tjeerd Ketel 28 Feb '12

28 Feb '12

Dear all, The comments we posted at 8 February about LHCB-PAPER-2011-030 have been answered in detail by Valerie Gibson. - "Pseudo-decay time" is guide line from Editor Board. - "Mixed events" were tried for background. It turned out difficult to get the right mix of photons due to correlations. The background fitted well at low pT. - The Chigen authors did produce the specific predictions. - and more ... see http://cdsweb.cern.ch/record/1427716 Best regards, Tjeerd ---------- Forwarded message ---------- Date: Tue, 28 Feb 2012 13:57:21 +0100 From: CERN Document Server Submission Engine <cds.support(a)cern.ch> To: tjeerd(a)nikhef.nl Subject: LHCB-PAPER-2011-030-001-COMMENT-012 (a comment has been made on your comment) Dear LHCb Colleague, The comment (LHCB-PAPER-2011-030-001-COMMENT-006) that you made on LHCB-PAPER-2011-030-001 (entitled: 'Measurement of the cross-section ratio $\sigma(\chi_c \to J/\psi \gamma) / \sigma(J/\psi)$ for prompt $\chi_c$ and $J/\psi$ production at $\sqrt{s} = 7$ TeV') has itself been commented on by Tjeerd Ketel [CERN - PH/ULB] (tjeerd(a)nikhef.nl). This new comment (LHCB-PAPER-2011-030-001-COMMENT-012) may be seen at http://cdsweb.cern.ch/record/1427716 Best regards, The CERN Document Server Server support Team

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[Bfys-physics] Bfys Meeting at Friday 24 February 9:45 h in H331 and EVO
by Tjeerd Ketel 28 Feb '12

28 Feb '12

Bfys Meeting at Friday 24 February 9:45 h in H331 and EVO Dear Colleagues, I have booked a Bfys Meeting in H331 and EVO for Friday 24 February from 9:45 to 10:30 h: 9:45 h: "Introduction and short discussion of LHCb-PAPER-2012-004 on Polarization amplitudes and asymmetries in B0s -> phi phi" by Roel Aaij This paper can be found in https://cdsweb.cern.ch/record/1425079? and is assigned to Nikhef for comments. With this introduction by Roel I hope to stimulate you to read it and to send comments in the week before Wednesday next week. Best regards, Tjeerd =================================================================== Slides are already available at the Nikhef Calendar: http://agenda.nikhef.nl/conferenceDisplay.py?confId=1816 =================================================================== You have BOOKED a meeting in EVO (http://evo.caltech.edu). Title: Nikhef Description: Bfys Meeting 9:45 - 10:30 Community: LHCb Password: n328 Meeting Access Information: - Meeting URL http://evo.caltech.edu/evoNext/koala.jnlp?meeting=MeMMMu2v29DaDB9M9lDv9e - Password: n328 - Phone Bridge ID: 481 2676 Password: 6287 EVO Phone Bridge Telephone Numbers: --------------- - Switzerland (CERN, Geneva) +41 22 76 71400 - Netherlands (Nikhef, Amsterdam) +31 20 7165293 Dial '2' at the prompt - Skype (tm) (World-wide) evo.phone See: http://evo.caltech.edu/evoGate/Documentation/extclient/skype/skype.html ===================================================================

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[Bfys-physics] Conference report circulation: LHCb-CONF-2012-003 (fwd)
by Tjeerd Ketel 28 Feb '12

28 Feb '12

Dear colleagues, The comments on "Measurement of the differential branching fraction ratio B(B0s->phi mu mu)/B(B0s-> J\psi phi)" have been posted as comment 4 at: https://cdsweb.cern.ch/record/1424683 Best regards, Maurizio and Tjeerd ---------- Forwarded message ---------- Date: Thu, 23 Feb 2012 11:30:05 +0100 From: Maurizio Martinelli <martinel(a)nikhef.nl> To: Tjeerd Ketel <tjeerd(a)nikhef.nl> Subject: Re: [Bfys-physics] Reminder: Conference report circulation: LHCb-CONF-2012-003 (fwd) Dear Tjeerd, I received comments only from you and Patrick. I merged them, added some of my comments and posted to the CDS. Cheers, Maurizio -- Maurizio Martinelli LHCb Nikhef CERN, office 13-1-26 CH-1211 Genève Tel: +41 (0)227676309 On Feb 23, 2012, at 11:26 AM, Tjeerd Ketel wrote: Dear Maurizio, Did you get other comments? Best regards, Tjeerd ---------- Forwarded message ---------- Date: Tue, 21 Feb 2012 15:45:10 +0100 (MET) From: Tjeerd Ketel <tjeerd(a)nikhef.nl> To: bfys-physics(a)nikhef.nl Subject: [Bfys-physics] Reminder: Conference report circulation: LHCb-CONF-2012-003 Please comment today, or let Maurizio know that your comments are still coming tomorrow. Tjeerd On Thu, 16 Feb 2012, Tjeerd Ketel wrote: Dear colleagues, Marcel suggested that we do not discuss this CONF-report in a Bfys Meeting as the time is short. It is a nice and short report for Moriond. Please, read it and send your comments before Wednesday 22 to Maurizio, martinel(a)nikhef.nl He will collect, select and send around the comments on Wednesday. And then post the comments on Thursday 23 (the deadline). Best regards, Tjeerd ---------- Forwarded message ---------- Date: Thu, 16 Feb 2012 09:30:01 +0000 From: Raluca Muresan <raluca.muresan(a)cern.ch> To: "lhcb-general (LHCb General mailing list)" <lhcb-general(a)cern.ch> Subject: Conference report circulation: Measurement of the differential branching fraction ratio B(B0s→ϕμμ)/B(B0s→J/ψϕ) Dear Colleagues, A conference report is available for your comments: Title : Measurement of the differential branching fraction ratio B(B0s→ϕμμ)/B(B0s→J/ψϕ) Contact authors: Paul Schaack, Andrei Golutvin Referees : Benoit Viaud (chair), Bernardo Adeva, Joerg Marks (EB) Institutes : NIKHEF, Netherlands. Ferrara, Italy Conference note: LHCb-2012-003 Analysis note : ANA-2011-051 Deadline : 23.02.2012 e-group : lhcb-conf-2012-003-reviewers Link : https://cdsweb.cern.ch/record/1424683 Twiki : https://twiki.cern.ch/twiki/bin/view/LHCbPhysics/Bs2PhiMuMu Please send any comments via the CDS system. If you wish to receive notification of comments as they come in, then subscribe yourself to the e-group. After the deadline, the referees are charged with approving the report for public release, once they are satisfied that any comments have been taken into account. You can find all reports open for comments via the EB web-page, by clicking on Current Drafts. http://lhcb.web.cern.ch/lhcb/edboard/EditorialBoard.html All the best, Raluca Muresan on behalf the EB _______________________________________________ Bfys-physics mailing list Bfys-physics(a)nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics

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[Bfys-physics] Conference report circulation: LHCb-CONF-2012-003
by Tjeerd Ketel 21 Feb '12

21 Feb '12

Dear colleagues, Marcel suggested that we do not discuss this CONF-report in a Bfys Meeting as the time is short. It is a nice and short report for Moriond. Please, read it and send your comments before Wednesday 22 to Maurizio, martinel(a)nikhef.nl He will collect, select and send around the comments on Wednesday. And then post the comments on Thursday 23 (the deadline). Best regards, Tjeerd ---------- Forwarded message ---------- Date: Thu, 16 Feb 2012 09:30:01 +0000 From: Raluca Muresan <raluca.muresan(a)cern.ch> To: "lhcb-general (LHCb General mailing list)" <lhcb-general(a)cern.ch> Subject: Conference report circulation: Measurement of the differential branching fraction ratio B(B0s→ϕμμ)/B(B0s→J/ψϕ) Dear Colleagues, A conference report is available for your comments: Title : Measurement of the differential branching fraction ratio B(B0s→ϕμμ)/B(B0s→J/ψϕ) Contact authors: Paul Schaack, Andrei Golutvin Referees : Benoit Viaud (chair), Bernardo Adeva, Joerg Marks (EB) Institutes : NIKHEF, Netherlands. Ferrara, Italy Conference note: LHCb-2012-003 Analysis note : ANA-2011-051 Deadline : 23.02.2012 e-group : lhcb-conf-2012-003-reviewers Link : https://cdsweb.cern.ch/record/1424683 Twiki : https://twiki.cern.ch/twiki/bin/view/LHCbPhysics/Bs2PhiMuMu Please send any comments via the CDS system. If you wish to receive notification of comments as they come in, then subscribe yourself to the e-group. After the deadline, the referees are charged with approving the report for public release, once they are satisfied that any comments have been taken into account. You can find all reports open for comments via the EB web-page, by clicking on Current Drafts. http://lhcb.web.cern.ch/lhcb/edboard/EditorialBoard.html All the best, Raluca Muresan on behalf the EB

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[Bfys-physics] Reminder Bfys Meeting at Wednesday 15 February 11:00 h
by Tjeerd Ketel 14 Feb '12

14 Feb '12

Bfys Meeting at Wednesday 15 February 11:00 h in N328 and EVO Dear Colleagues, I have booked a Bfys Meeting in N328 and EVO for Wednesday 15 February 11:00 h 11:00 Practise lecture for Lake Louise Winter Institute 19-25 February by Rob Lambert on: "Heavy Flavour Physics an introduction and review" Best regards, Tjeerd =================================================================== Slides are already available at the Nikhef Calendar: http://agenda.nikhef.nl/conferenceDisplay.py?confId=1807 =================================================================== You have BOOKED a meeting in EVO (http://evo.caltech.edu). Title: Nikhef Description: Bfys Meeting 11:00 - 12:00 Community: LHCb Password: n328 Meeting Access Information: - Meeting URL http://evo.caltech.edu/evoNext/koala.jnlp?meeting=MsMiMI2t22DsDa9l9vDt9s - Password: n328 - Phone Bridge ID: 473 5344 Password: 6287 EVO Phone Bridge Telephone Numbers: --------------- - Switzerland (CERN, Geneva) +41 22 76 71400 - Netherlands (Nikhef, Amsterdam) +31 20 7165293 Dial '2' at the prompt - Skype (tm) (World-wide) evo.phone See: http://evo.caltech.edu/evoGate/Documentation/extclient/skype/skype.html ===================================================================

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[Bfys-physics] Reminder Meeting at Friday 10 February 9:30 h in H331
by Tjeerd Ketel 10 Feb '12

10 Feb '12

This is an early reminder of the analysis presentation by Rob Lambert. Please, note the colloquium room H331 at Nikhef AND a room at CERN to join the meeting !!! Bfys Meeting at Friday 10 February 9:30 h in H331, 14-4-030 and EVO Dear Colleagues, I have booked a Bfys Meeting in H331 and EVO for Friday 10 February 9:30 h: At Nikhef room H331 and at CERN room 14-4-030: 9:30 News by Marcel Merk. 9:45 Analysis presentation on the delta m_s and delta m_d measurement in semileptonics, presented by Rob Lambert. 10:45 End. The room is reserved for the Nikhef colloquium. Best regards, Tjeerd =================================================================== Nikhef Calendar: http://agenda.nikhef.nl/conferenceDisplay.py?confId=1795 =================================================================== You have BOOKED a meeting in EVO (http://evo.caltech.edu). Title: Nikhef Description: Bfys Meeting 9:30-10:45 Community: LHCb Password: n328 Meeting Access Information: - Meeting URL http://evo.caltech.edu/evoNext/koala.jnlp?meeting=MaMDMt2I2BD2DB9i9tDI9a - Password: n328 - Phone Bridge ID: 467 0960 Password: 6287 EVO Phone Bridge Telephone Numbers: --------------- - Switzerland (CERN, Geneva) +41 22 76 71400 - Netherlands (Nikhef, Amsterdam) +31 20 7165293 Dial '2' at the prompt - Skype (tm) (World-wide) evo.phone See: http://evo.caltech.edu/evoGate/Documentation/extclient/skype/skype.html ===================================================================

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[Bfys-physics] Bfys Meeting at Wednesday 15 February 11:00 h
by Tjeerd Ketel 08 Feb '12

08 Feb '12

Bfys Meeting at Wednesday 15 February 11:00 h in N328 and EVO Dear Colleagues, I have booked a Bfys Meeting in N328 and EVO for Wednesday 15 February 11:00 h 11:00 Practise talks for Lake Louise Winter Institute 19-25 February by Rob Lambert on: "A pedagogical introduction to heavy flavour" and "Recent flavour physics results from the LHC" Best regards, Tjeerd =================================================================== Nikhef Calendar: http://agenda.nikhef.nl/conferenceDisplay.py?confId=1807 =================================================================== You have BOOKED a meeting in EVO (http://evo.caltech.edu). Title: Nikhef Description: Bfys Meeting 11:00 - 12:00 Community: LHCb Password: n328 Meeting Access Information: - Meeting URL http://evo.caltech.edu/evoNext/koala.jnlp?meeting=MsMiMI2t22DsDa9l9vDt9s - Password: n328 - Phone Bridge ID: 473 5344 Password: 6287 EVO Phone Bridge Telephone Numbers: --------------- - Switzerland (CERN, Geneva) +41 22 76 71400 - Netherlands (Nikhef, Amsterdam) +31 20 7165293 Dial '2' at the prompt - Skype (tm) (World-wide) evo.phone See: http://evo.caltech.edu/evoGate/Documentation/extclient/skype/skype.html ===================================================================

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