1. Request and expectations from the experiments J. Boyd, C. Schwick (LPC) Chamonix LHC workshop 27/1/2016 1Experiment requests - Chamonix 2016 Many thanks to the experiment LPC contacts, and to Benedetto and Emilio (ex-LPC) for their valuable input for this talk!

2. Overview A brief Introduction to the new LPC 2015 running High lumi pp running in 2016 Special runs – VdM – very high β* Heavy Ion running 2Experiment requests - Chamonix 2016

3. Quick Introduction I am the new LHC Programme Coordinator (LPC) for 2016/2017 with Christoph Schwick as deputy, taking over as coordinator for 2018 – In general I will be the main contact, and will have the final say in decision making – but during some weekends, holidays Christoph will be the contact, and will have the authority to make decisions when required. There is a common LPC phone (x79977) that will be routed to the ‘LPC on call’ – We aim to work closely together and in general to speak with one voice We are excited to take on this challenging and interesting role, but since we are new to this please excuse our ignorance (we hope we can learn soon!) We are currently: – updating LPC webpage: http://lpc.web.cern.ch/lpc/ (now contains link to minutes of LPC meetings)http://lpc.web.cern.ch/lpc/ – updating the experiment luminosity files/plots for 2015 data, and will push this to be up and running during the 2016 run Many thanks to Benedetto and Emilio (outgoing LPCs) for their work over the last years, and with their help getting us up to speed in many areas! 3Experiment requests - Chamonix 2016

4. Updated Mandate Previous mandate >10 years old Updated mandate follows the same spirit as the old one, but with some clarifications and updates based on operational experience Now available through LPC webpage 4

5. 2015 running 2015 was a year for commissioning 13 TeV and 25 ns running After a challenging start the machine performed well, and this bodes well for 2016 running We believe the programme, including: – 4/fb of delivered 13 TeV data – data taking with special optics for LHCf (19m β*), TOTEM (90m β*) – VdM scans (2 at 13 TeV), as well as for Pb-Pb and p-p reference run – ~0.7/nb of delivered Pb-Pb data (exceeding design luminosity!) – 30/pb of p-p 5 TeV reference data was well planned and executed especially considering the initial delays Many thanks from all the experiments to the LHC! We believe this sets us up well for a productive 2016 run 5Experiment requests - Chamonix 2016

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8. 2016 requests/expectations - summary Lots of 13 TeV p-p data for ATLAS/CMS (~30/fb @ 25 ns): – Experiments will exceed the sensitivity of Run-1 data in many physics channels – 40cm β* (approximately twice the luminosity/pileup of 2015) – Hope to exceed design luminosity of 1e34 – Leveling LHCb/ALICE in same way as 2015 In addition to high intensity p-p we foresee the following: – One early VdM scan (with possibility of another depending on analysis) – A high β* (~2.5km) running period (few days + setup) (for TOTEM/ALFA) (no 90m β* run is foreseen in 2016) – 4 week Heavy Ion period, details still under discussion – LHCf do not foresee taking data in 2016 except in a possible 8 TeV p-Pb run 8Experiment requests - Chamonix 2016

9. Beam Energy The experiments would like to keep running at 13 TeV for 2016 – Gives consistent 2015/6 dataset (avoids re-making Monte Carlo simulation samples) – Avoids delays due to magnet training – The experiments prefer a large increase in energy (e.g. 0.5 TeV) and for any change to happen in a YETS – It would be nice to reduce the uncertainty on the beam energy as this affects precision measurements (e.g. top production cross section) not a request for MD time on this 9Experiment requests - Chamonix 2016

10. Pileup As previously stated ATLAS/CMS set a maximum pileup of 50 (for the beginning of the fill, less as an average) – Beyond this the sensitivity for some important physics analyses become significantly degraded – and leveling would be needed (details of this would need to be discussed further) – For luminous region length of >5cm the pileup density (with μ<50) is not considered a problem shrinking beam length as in 2015 not a problem for this as luminosity also falls during the fill All experiments support running with 25 ns bunch spacing 10Experiment requests - Chamonix 2016

11. Configuration during nominal running ATLAS/CMS: – β*=40cm (or lowest achievable) LHCb: – Same as in 2015 – (β*=3m, leveling at =1.1, as many colliding bunches as possible, regular flipping of dipole polarity) ALICE: – Mostly the same as in 2015 (β*=10 m) – Leveled (beam separation) to 5e30 ( =0.01) – New for 2016: regular flipping of magnet polarity (increased crossing angle of 240 μrad) Experiments support having non-colliding bunches (similar to 2015) as long as these do not cause instabilities 11Experiment requests - Chamonix 2016

12. Changes in beam spot size / position In 2015 running the longitudinal beam spot size shrank by ~20% during a fill – This is somewhat problematic for LHCb and ALICE as reconstruction efficiency depends on this – Request to reduce this effect (if possible without effecting luminosity production) LHCb/ALICE also observed movements of ~20mm in z-position of beam spot – Again problematic for physics analysis, and should be reduced if possible without affecting luminosity production All experiments would prefer the luminous centroid to be as close as possible to 0,0,0 – and for CMS a 1mm shift in x/y (as seen in 2015) is at the limit of affecting physics 12Experiment requests - Chamonix 2016 plot from LHCb

13. Special requests for commissioning & ramp-up 1 ATLAS/CMS request splash events ~10/side – if not big impact on schedule For all experiments it would be useful to have stable beam collisions with pilots/nominal bunches as early as possible for detector commissioning (some upgraded detectors / trigger systems need commissioning with data) As in 2015 request to perform TOTEM/CT-PPS alignment and loss maps for Roman Pots as part of the initial commissioning 13Experiment requests - Chamonix 2016

14. Special requests for commissioning & ramp-up 2 It would be useful for experiments to know the ramp-up configuration (filling schemes) ahead of time to plan trigger setups (for LPC!) It would be beneficial for ATLAS to have bunches spread out as much as possible (i.e. shorter trains) during the ramp-up to avoid large dead-time from fixed frequency veto’s related to the IBL CMS interested in a special run early in the year (with single/few bunches) with as high of pileup as possible (~50?) in order to help commission the trigger, in view of the expected increase in pileup during the next couple of years – Assuming this doesn’t not have a big effect on the schedule 14Experiment requests - Chamonix 2016

15. Miscellaneous items - 1 ATLAS/CMS will likely request some periods of low/medium pileup running (separation leveling) transparent to other experiments – e.g. ATLAS request: µ ~ 0.5, ~1 pb-1 -> 1.5h @ 2500 bunches Experiments request an ‘after glow calibration’ run – 4 well spaced bunches, high intensity, nominal optics, need detectors operating normally for this ATLAS/CMS would like isolated bunches in filling scheme during the ramp-up for ‘out of time pileup’ studies. When the number of bunches is high this will be requested occasionally (~one fill per two weeks) As always, CMS will need stops for regeneration of the magnet cryogenic system every ~12 weeks 15Experiment requests - Chamonix 2016

16. Miscellaneous items - 2 ATLAS/CMS will install ZDC (& CASTOR for CMS) during TS3 (just before the Heavy Ion period) ATLAS Forward Physics (AFP) detector may request commissioning with beam (alignment) during 2016 – Hopefully mostly parasitic to normal LHC operation Extra 12 bunch injection used for beam transfer steering may cause significant loss of colliding bunches with full machine – Need to balance benefits versus loss of integrated luminosity 16Experiment requests - Chamonix 2016

17. VdM scans Experiments request one early VdM scan to allow preliminary luminosity calibration for summer conferences – Preferred date with current schedule is during week 20 – Need time before scan for detector commissioning, and pumping of luminometers (need 10/pb of high lumi running directly before scan – implies validation of VdM optics ahead of time, not directly before the scan) If problems observed with scan data, or significant drifting of luminometers, then possibility to request a second scan later in the year VdM setup similar to that used in 2015: – β* ~ 19 m (IP1 & 5), 24m IP8 – ε ~ 3 µm, – θXing = 0 (large at IP8) and (βx =βy) – Request also a length scale calibration (same optics as VdM) LHCb may take SMOG ‘fixed target’ Heavy Ion data during VdM fills (transparent to LHC and other experiments) – SMOG system will anyway be used for luminosity measurements during VdMs 17Experiment requests - Chamonix 2016

18. Beam settings: β* as high as possible (β*> 2 km). Total intensity below the SETUP BEAM limit => 3 (reduced) nominal bunches with 2 bunches colliding in IP1 and IP5. As low emittance as possible. Likely repetitive collimator scrapings (like in 2012 for β* = 1 km), but an optimized solution will be found in collaboration between LHC collimation, ATLAS-ALFA and TOTEM. Data taking in ADJUST mode (no STABLE BEAMS). Vertical Roman Pots positioned at 3 σ nominal or closer. Scheduling: 1 day of final setup and 3 days of data taking in the autumn (several fills needed and maybe different collimator settings to control background). Optics commissioning needs to be early in the year and well separated in time. Goal: Measure elastic proton-proton scattering in the Coulomb-nuclear interference region and potentially measure the luminosity independent of VdM scan Zero crossing-angle. Experiment requests - Chamonix 201618 Very High β* running

19. Beam settings: - β* as high as possible (β*> 2 km) - Zero crossing-angle - Total intensity below the SETUP BEAM limit => 3 (reduced) nominal bunches with 2 bunches colliding in IP1 and IP5 - As low emittance as possible - Vertical Roman Pots positioned at 3 σ nominal or closer - Likely repetitive collimator scrapings (like in 2012 for β* = 1 km), but an optimized solution will be found in collaboration between LHC collimation, ATLAS-ALFA and TOTEM - Data taking in ADJUST mode (no STABLE BEAMS) Scheduling: 1 day of final setup and 3 days of data taking in the autumn (several fills needed and maybe different collimator settings to control background). Optics commissioning needs to be early in the year and well separated in time. Experiment requests - Chamonix 201619 Measure elastic proton-proton scattering in the Coulomb-nuclear interference region and potentially measure the luminosity independent of VdM scan. Goal: Very High β* running

20. Experiment requests - Chamonix 201620 Measure elastic proton-proton scattering in the Coulomb-nuclear interference region and potentially measure the luminosity independent of VdM scan. Goal: Very High β* running Scheduling: - Optics commissioning needs to be early in the year and well separated in time - TOTEM request: 1 day of final setup and 3 days of data taking in the autumn (several fills needed and maybe different collimator settings to control background) - ATLAS/ALFA – request slightly less time for data-taking - Exact details to be discussed (both requests are for 24hrs of actual data-taking) - ALICE interested in taking data ‘parasitically’ in such a run assuming this is not problematic

21. Beam settings: - β* as high as possible (β*> 2 km) - Zero crossing-angle - Total intensity below the SETUP BEAM limit => 3 (reduced) nominal bunches with 2 bunches colliding in IP1 and IP5 - As low emittance as possible - Vertical Roman Pots positioned at 3 σ nominal or closer - Likely repetitive collimator scrapings (like in 2012 for β* = 1 km), but an optimized solution will be found in collaboration between LHC collimation, ATLAS-ALFA and TOTEM - Data taking in ADJUST mode (no STABLE BEAMS) Experiment requests - Chamonix 201621 Measure elastic proton-proton scattering in the Coulomb-nuclear interference region and potentially measure the luminosity independent of VdM scan. Goal: Very High β* running Scheduling: - Optics commissioning needs to be early in the year and well separated in time - TOTEM request: 1 day of final setup and 3 days of data taking in the autumn (several fills needed and maybe different collimator settings to control background) - ATLAS/ALFA – request slightly less time for data-taking - Exact details to be discussed (both requests are for 24hrs of actual data-taking) - ALICE interested in taking data ‘parasitically’ in such a run assuming this is not problematic LPC support this challenging special running period in 2016 - but we need to minimize the cost to high intensity running (from preparation time and data taking)

22. Heavy Ion running Significantly different requests from experiments on the Heavy Ion configuration Still under discussion, plan to converge on strategy before the March LHCC The current options available: 20162018 Ap-Pb @ 5 TeVPb-Pb @ 5 TeV Bp-Pb @ 8 TeVPb-Pb @ 5 TeV C remarks: A- favoured by ALICE, LHCb – dis-favoured by ATLAS/CMS B- favoured by ATLAS/CMS, LHCb, (LHCf would take data in such a run) – dis-favoured by ALICE C- favoured by ATLAS/CMS – but ALICE/LHCb favour having p-Pb in Run-2 Strong constraint from LHC to turn protons off before the Heavy Ion period in 2018 22Experiment requests - Chamonix 2016

23. Heavy Ion running Significantly different requests from experiments on the Heavy Ion configuration Still under discussion, plan to converge on strategy before the March LHCC The current options available: 20162018 Ap-Pb @ 5 TeVPb-Pb @ 5 TeV Bp-Pb @ 8 TeVPb-Pb @ 5 TeV C remarks: A- favoured by ALICE, LHCb – dis-favoured by ATLAS/CMS B- favoured by ATLAS/CMS, LHCb, (LHCf would take data in such a run) – dis-favoured by ALICE C- favoured by ATLAS/CMS – but ALICE/LHCb favour having p-Pb in Run-2 Strong constraint from LHC to turn protons off before the Heavy Ion period in 2018 Experiments would like a 5 TeV p-p reference run but there are differing requests on if this would be included in the Heavy Ion period or not. One option could be to take this during 2017, when no Heavy Ion run is foreseen (e.g. during ramp-up or at the end of year). 23Experiment requests - Chamonix 2016

24. 24 Draft schedule for 2016 (Jan-June) Proposed ~1 day Operational development for 2.5km β* Proposed ~2 day slot for VdM scans (optics to be setup ~2 weeks before) with LPC preliminary suggested updates Experiment requests - Chamonix 2016

25. 25 Draft schedule for 2016 (July-Dec) Proposed ~1 day Operational development for 2.5km β* Proposed few days 2.5km β* data-taking (details to be discussed) Configuration to be decided next month with LPC preliminary suggested updates Experiment requests - Chamonix 2016

26. 2016 requests/expectations - summary Lots of 13 TeV p-p data for ATLAS/CMS (~30/fb @ 25 ns): – Experiments will exceed the sensitivity of Run-1 data in many physics channels – 40cm β* (approximately twice the luminosity/pileup of 2015) – Hope to exceed design luminosity of 1e34 – Leveling LHCb/ALICE in same way as 2015 In addition to high intensity p-p we foresee the following: – One early VdM scan (with possibility of another depending on analysis) – A high β* (~2.5km) running period (few days + setup) (for TOTEM/ALFA) (no 90m β* run is foreseen in 2016) – 4 week Heavy Ion period, details still under discussion – LHCf do not foresee taking data in 2016 except in a possible 8 TeV p-Pb run 26Experiment requests - Chamonix 2016

27. 27 AFP – ATLAS Forward Physics / CT-PPS – CMS TOTEM Proton Precision Spectrometer: Installed ~220/210m from IP Designed to study diffractive physics, and anomalous coupling of W,Z to photon