Status of LHC, CMS & India in CMS A. Gurtu Tata Institute of Fundamental Research, Mumbai

Status of LHC, CMS &India in CMS

A. Gurtu

Tata Institute of Fundamental Research, Mumbai

A. Gurtu: Talk at "Workshop on LHC Physics", TIFR, Mumbai, 4-8 September 2006

LHC why, what, when ? The overall picture.

• Existing: Standard Model (SM) of particle physics

• Constituent particles:

Quarks (u,d) (c,s) (t,b)

Leptons (e, mu, tau) & their respective neutrinos

• Force carrying (gauge) particles

electroweak: photon, Z, W(+-)

strong: gluons (8)

• Remnant of Higgs field: Higgs

• Forces act through EXCHANGE of particles.

Excellent agreement of (almost) all data within framework of the standard model.

Exception is non-zero mass of neutrinos, deduced from study of solar, reactor based and atmospheric neutrinos.

AND,

Higgs remains to be discovered (mass > 114 GeV from LEP)


Need for LHC

• While very successful, SM can’t be the ultimate theory.

• Beyond SM (BSM) scenarios include Supersymmetry (SUSY) or technicolor, or, …, but most predict occurrence of new particles/ phenomena at the TeV scale.

• Earlier LEP II and now the current highest energy machine, Tevatron (Ecm 2 TeV) have failed to detect the Higgs or any BSM signal.

• Thus, to progress further in the understanding of particle physics and of the ubiquitous cosmological dark matter, it is crucial to extend the high energy frontier substantially.

• Hence LHC, the high luminosity proton-proton collider, at Ecm = 14 TeV.

• LHC would extend the search for the SM Higgs to 800 GeV or more (theoretical upper limit), and detect the predicted SUSY particles.


CERN Accelerator Complex


LHC Schedule (from June CMS Week)June 7 meeting between 4 LHC experiments, the Machine, the DDG Engelen and DG Aymar.

Experiments told to have beam pipe in place, connected and ready by 1st Sept instead of 1st July 2007. CMS 'Ready to Close' is then be set to 31 August 2007.

Schedule for the 2007 pilot run is: Date 1= 1 Sept (i-e 2 month delay wrt to official LHC

schedule): Expts ready to close with beam pipe installed.

Date 2= Date 1 + 6 weeks (?) = ~ 15 Oct: Expts closed ready for collisions.

Following June Scientific Policy Committee meeting it is decided that in the run of 2007 the LHC will start commissioning with collisions at injection energy (450 GeV). Discussions are ongoing on how much higher in energy the machine can go before the winter shutdown.




CMS detector ¼ Longitudinal View

HB

HEHF

HO


Post Physics-TDR: Start up PhysicsPTDR work was done with old software: OSCAR and ORCA.

Highest priority: Switch to CMSSW. Already planned: MTCC and CSA06.

In addition: Get prepared for first beam now at low energy: Detector startup procedures, Calibrations and Alignment with minimum bias, Trigger for start up, Jet/single muon/dimuons/W/Z cross sections.

Get prepared for 2008 physics run (several fb-1 at 14 TeV), HLT update, Trigger tables: from 1029 to 1033 …

Request from SC: Organise (before the Sept CMS Week) a general CMS-wide workshop to discuss the plans for first beam. Draw the lessons learnt from MTCC on detector startup procedures.

Sub-detector communities are already switching to commissioning mode and vertical integration (hardware, electronics, DAQ, trigger and CPT):

Tracker: Commissioning in TIF (Set up TK Analysis Centre, TAC) ECAL: Commissioning SMs with CosmicsHCAL and Muons: Commissioning with Cosmics at SX5MTCC: Combined system test.


MTCC- Magnet Test Cosmic Challenge (from June CMS Week)

MTCC Coordination objectives:

• To get together a team from all sub-detectors and central systems working together…• To put together some first manuals for CMS operation. The plan is to make available to all the collaboration: e-log, event display, basic DQM, page1, webcams. • Encourage remote participation (within constraints of the provisional setup) …

Written post-completion analysis of successes, failures, lessons learned will be made available.


Summary of Magnet tests as of 28 August 2006: 4 Tesla field reached !







Progress in CC till 28 August


Startup Workshop Guidelines from CMS-MB 28 Aug 06

For each individual sub-detector presentations:The startup procedure: what happens as soon as each sub-detector and its electronics are installed in the underground caverns, one month before the first beam, what happens with single beam, what happens with the first collisions in the detector. The detector synchronization should be addressed explicitly.The calibration and alignment roadmap: what are the assumed measurements prior to any in-situ procedures. The hardware elements that need to be ready prior to each step in the roadmap. The software and procedures necessary to carry out the calibration and alignment without and with beam. The dependence on other CMS detectors.The trigger roadmap for the detector. Inputs to the trigger, timing and cross-checks necessary.The quantities that will have to be monitored early-on to establish the correct functioning of the sub-detector.The datasets needed to perform the actions above.Experience gained from the MTCC. Lessons learned, especially in what concerns above points.


Draft Agenda Startup Workshop (1)Wednesday 20th September (5h)

14:00-14:10 Introduction and goals of the meeting

14:10-14:30 LHC machine Plans

14:40-15:10 Overview of MTCC, Installation Schedule in 2007

15:20-15:50 Tracker

16:00-16:30 ECAL

16:40-17:00 Break

17:00-17:20 Drift Tubes

17:30-17:50 CSC’s

18:00-18:20 RPC’s

18:30-18:50 Alignment


Draft Agenda Startup Workshop (2)Thursday 21st September (4h)

08:30-09:00 HCAL (30’)

09:10-09:30 Luminosity, forward region, etc* (20’)

09:40-10:00 Trigger* (20’)

10:10-10:30 DAQ (20’)

10:40-11:00 Break (20’)

11:00-11:20 Trigger MTCC experience (20’)

11:30-11:50 DAQ MTCC experience (20’)

12:00-12:15 Conclusions and Future Outlook (TSV, 15’)

12:30 Close

* should include scintillator hodoscopes


CMS schedule v35.0

magnet test complete: end Oct 06

central wheel (YB0) lowering: Dec 06

tracker installation: Apr 07

“ready to close” 31 Aug 07

5 task sequences under detailed study.


India in LHC

• It is for the first time that India is participating in a comprehensive and well coordinated fashion in a large international frontier science program, thanks to the encouragement and financial support of the funding agencies.

• Indian accelerator research labs, led by RRCAT, Indore, and BARC, Mumbai, have contributed substantially, in kind, towards the LHC machine.

• Indian scientists/software personnel are also contributing in-kind to the development of GRID software.

• In addition to the India-CMS collaboration, there is also an India-ALICE collaboration which is also contributing to all aspects of the ALICE experiment.


India-CMS Collaboration

• Panjab U, Delhi U, BARC, TIFR (2 groups), and recently, Visva-Bharati U

• Hardware responsibilities:

- Outer hadron calorimeter.

Physics necessity: ensure more hermetic detector to look for missing energy signals of LSP/ other new physics.

- Silicon Pre-shower Detector.

Physics necessity: discriminate between photon/pi0 to detect the Higgs 2 photon decay mode (for low mass Higgs favored by existing data)


CMS detector ¼ Longitudinal View

HB

HEHF

HO


HO basic design

• Detector element is a plastic scintillator tile which produces light when charged particles pass through it

• This light is collected by embedded WLS fibers (4 sigma grooves/tile)

• Light is transported to HPD detector via clear optical fibers spliced to WLS fibers

• Size and placement of the tiles is matched to geometric towers in the CMS calorimeters

• Tiles are grouped together and packed in “trays” for ease of handling, and 6 trays in each phi sector are in turn inserted inside aluminum honeycomb housings.


Design Consideration

• Basic Detector Elements should map the barrel hadron Calorimeter ( HB) towers of granularity 0.087 X 0.087 in and

• Should be able to see MIPS.

10 mm thick Bicron BC408 scintillatorto be used as the active element.

Use 0.94 mm dia WLS Kuraray double clad fibers ( in shapped grooves), splicedto clear fibers to carry light to HPDs locatedon the outer edge of the muon system.


HO Tray Design• All the tiles in the

same slice of a ring will be packed as a single mechanical unit called the “tray”.

• It will cover the entire length of a muon ring along Z.

• Along , it will only be one tile wide ( 50)


Tile, Tray (one of 432 trays)

PPP tile with 4 grooves visible

Pigtail with connector

Finished

Tray


HO hardware status/plans

• Fabrication of detectors done at TIFR and Panjab University.

• Honeycomb panels from Bangalore; assembled in Mumbai industry.

• By April 2004 all 432 trays & 72 housings for HO detectors had been sent to CERN.

• In 2005-06: installation and cabling being carried out.

• Testing of read-out boxes, cable routing, cable lengths, cable fabrication carried out.

• R+2 done; R0 (2 layers); R+1, R-1 by X-mas 2006

• R-2 and all 3 & 9 o’clock positions in 2007.


Installation of one HO housing containing 6 trays in CMS magnet


HO installation, RBX etc


10 Sectors (out of 12) installed in 2 rings (out of 6)


ECAL 1 Crystal BARREL (EB) 2 Crystal ENDCAPS (EE) 2 Preshower ENDCAPS (SE)

Coverage Behind the Tracker and in front of EE

1.653 < |η| < 2.6


Si-PSD hardware

• To fabricate 1000 Silicon strip detectors for the pre-shower end-cap of the CMS detector (~25% of total).

• Being carried out at BEL. Yield (around 50%) and production rate quite satisfactory.

• Currently: 900 detectors satisfying all specs are ready. Expect the remainder to be finished within a few months.

• Next step is to mount them on ceramic supports and then on aluminum plates to complete the module production process in India. Readout chips bonding and other electronics mounting on these will be completed at CERN.

• Received 10 sets of ceramic & aluminum tiles. These prototypes were assembled at BEL where full job will be carried out. Tests show mounting was OK.


Reverse IV characteristics of all 32 strips of a sensor

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

0.0 50.0 100.0 150.0 200.0 250.0 300.0

Bias Voltage (Volts)

Revers

e c

urr

en

t (M

icro

am

ps)


Reverse CV characteristics of all 32 strips of a sensor

0.0E+00

2.0E-11

4.0E-11

6.0E-11

8.0E-11

1.0E-10

1.2E-10

1.4E-10

1.6E-10

1.8E-10

0.0 50.0 100.0 150.0 200.0

Bias Voltage (Volts)

Cap

acit

an

ce (

Fara

ds)

*Prototype detectors with high energy resolution of 18keV

developed at BEL for DAE applications


Silicon detector micro-module made at CERN

Detector mounted on ceramic & Al tile

Hybrid with front endElectronics-PACE chip


Current at 300V for 32 strips of the detector 33304010000120

0.00E+00

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

6.00E-08

7.00E-08

8.00E-08

9.00E-08

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

STRIP NO.

CU

RR

EN

T (

A)

Initial

after Ceramic

after Al tile


Results of Micro Module assembly

• There is no degradation of leakage current during assembly.

• There is no mechanical damage to the detector (i.e chipping etc.)

• For all ten prototype modules the total detector current is almost the same before and after assembly.


Production plan

• The silicon detector production is being continued at BEL to reach the target of 1000 NOs of detectors + 10% spare – expected to complete within few months with a target of processing 150 wafers per month

• The final design for the micro-module (being) finalized. Right now Anna-Piesert from CERN is in India (BARC + BEL, Bangalore) to help initiate micro-module production.


India-CMS: to Physics TDR

• Mid 2006: CMS Physics TDR (Technical Design Report)

• India-CMS has contributed towards this within a collaborative CMS framework

• Various members were in contact with their respective CMS physics topics team leaders to participate in this effort.

1. W + jets2. Si-PSD related: Transverse

shaping of Pb absorber3. Direct photon and photon + 1

jet studies4. Search for Invisible Higgs5. Search for SUSY in high tan

beta region with tri-leptons6. High E_T jets in 2->2 hard

processes7. Higgs to di-muon decay8. QCD alpha_s, Top quark9. Heavy Ion studies


GRID project, Tier-2/3 CMS centers at TIFR/other institutions



India-CMS Tier-2 Centre at TIFR

• A prototype of a Tier-2 centre was set up at TIFR and is currently under upgradation, to around 20% of nominal capacity

• Bandwidth is 34 Mbps 1:1 point-to-point line. Expected to be enhanced to 622 Mbps within a year.

• Connectivity will be provided from this Tier-2 centre to the other India-CMS institutions (BARC-Mumbai, Delhi, PU-Chandigarh, VBU-Santiniketan).


Summary

• Thus, preparations for LHC start-up, operation of CMS and participation of India in the next particle physics era is well underway.

• The new energy frontier would be crossed in 2008 and preliminary results on Higgs and new particle searches would start coming soon after that.

• A lot of these issues will be taken up at this workshop.


Thank you


LHCC Feedback (from June CMS Week)

ConclusionsFor the first time, all major detector systems are in full production, and the strong QC culture should minimise future surprises... Recent milestones are being met, and CMS can now make realistic schedule extrapolations and optimisations.

Nevertheless the schedule to be ready by July 31 is highly aggressive, and must survive the “phase shift” from surface to underground work…

A reasonable contingency (~2 mo) is highly appropriate for planning, even if it is not “PC (politically correct)” at this time to say so.

Actually DONE now.


CMS & new LHC Schedule (from June CMSWeek)

Additional 2 months now included in the new CMS master schedule Version35.

Reminder of our primary goals for the initial detector: EB + silicon strip TK for pilot run. Low luminosity detector: EE + pixels

Given the new date for CMS ready to close of 31st August and the lower energy in 2007, consider the possibility of:

Installation of the full pixel system already for the pilot run. This would have the great benefit of having the full tracker system aligned with tracks and commissioned for physics.

Preparation and installation of one Dee of the ECAL EndCap (EE) for the pilot run.

Trigger tables and simulations should then be prepared for the new beam conditions : 0.9 to 2? TeV collisions at ~1030 and the new initial detector.

Details still to be clarified.

Documents

Status of LHC, CMS & India in CMS A. Gurtu Tata Institute of Fundamental Research, Mumbai