TOTEM Status Report Hubert Niewiadomski on behalf of the TOTEM Collaboration

TOTEM Status Report
Hubert Niewiadomski
on behalf of the TOTEM Collaboration
LHCC Open Session, 19 November 2014
TOTEM APPARATUS
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
2
September 2014
TOTEM timing TDR
CT-PPS TDR
DP Si operation
& RP movement &
calibration & interlock LHC
LHC LS1 access for RP installation
Hubert Niewiadomski
November 2014
January 2014
CMS-TOTEM
MoU
components
integrated into LHC
Cooling & vacuum
tests
RP operation with DAQ
March 2015
Restart LHC
Run 2
Commissioning
ongoing
June 2013
consolidation
& upgrade
August 2014
March 2013
LHCC
ROMAN POT: Milestones during LS1
RP operation from CCC
Timing detector R&D
Test beams at CERN & PSI
3
RP installation in LHC tunnel completed
Upgraded Roman Pot System
Existing RP220
(vertical + horizontal RPs)
RP147 relocated to 203-214m
(vertical + horizontal RPs)
November 2014
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
4
T1 & T2 (integrated in CMS)
T1 telescope
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



T2 telescope
Maintenance is over
Commissioning done at surface
Ready to be installed
Integrated in the CMS installation schedule
Installation probably in February 2015
Hubert Niewiadomski
 Service work done
 Installed in CMS
LHCC Open Session, 19 November 2014
5
TOTEM diamond timing detectors R&D
Objective:
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•
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4 timing detectors per arm in vertical RPs
Installation by mid 2016
50 ps resolution per arm (100 ps per detector)
R&D:
•
•
Several test beams with different hardware setup (June – Oct. 2014)
Optimisations (connection capacitance, amplifier bandwidth, rise time, S/N…)
Common test configuration:
particle
Offline waveform analysis
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
6
Timing detectors test beams
July 2014 (PS, T9):
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•
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Diamonds & charge sensitive amplifiers from CIVIDEC
Diamonds 4mm  4mm, 500 μm thick
Large sensor-amplifier connection capacitance (15 pF)
(t)=280 ps
August 2014 (PS, T9):
•
•
•
Diamonds & charge sensitive amplifiers from CIVIDEC
PCB connection length reduced (5 pF achieved)
Slight improvement: (t)=200 ps
October 2014 (SPS, H8)
•
CIVIDEC diamonds with 2 types of TOTEM amplifiers:
•
•
(t)=200–250 ps
Important experience gained
(1ns rise time and low S/N; 3 ns rise time and high S/N 15)
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
7
November 2014 (SPS, H8, parasitic)
• Test of diamonds detectors from GSI with associated hybrids
J. Pietraszko, L. Fabbietti, W. Koenig, M. Weberc for the HADES Collaboration
NIM A 618 (2010) 121-123
• (t)  80 ps per detector obtained with MIPs
• Production of a TOTEM-hybrid based on the GSI design is ongoing
Time difference between the 2 detectors
VERY PRELIMINARY
𝜎Δ𝑡 = 116 ps
timing resolution:
𝜎∆𝑡
= 82 ps
2
2 diamond
detectors
∆t (ns)
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
8
Timing detectors: plans
18-22 November 2014 (SPS, H8)
•
•
•
Confirmation of the results
Further tests: dependence on charge release, efficiency, possibility of time walk,
correction procedure.
Signal sampling with the SAMPIC chip (CEA/Saclay, up to 10Gs/s, 16 channels)
8-15 December 2014 (SPS, H8)
•
•
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Hybrids tests as soon as they are ready
Influence of pixel capacitance, diamond purity
Efficiency studies, tests of different second stage amplifiers
2015 test beams requested
• Characterization of first prototypes and final detectors and complete system
LHC timing infrastructure installation by the end of LS1
• First timing detectors may appear in LHC by September 2015
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
9
ADDENDUM TO THE TIMING TDR
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
10
Pileup suppression, timing detectors
applicability
Proton tags – direct signature of CD
radical enhancement compared to a rapidity gap trigger
– (pTx,CMS – pTx,TOTEM)  50 MeV
– (pTy,CMS – pTy,TOTEM)  20 MeV
High proton
kinematic
resolution
Vertical timing detectors
– T = 50 ps (baseline):
– T = 100 ps :
– No timing detectors:
impurity of 5%
impurity of 8.5%
impurity of 22%
T2 veto (5.3<|η|<6.5)
inclusive searches
pT CMS-TOTEM agreement (at 𝑠 = 13TeV):
exclusive searches
Proton based transverse vertex reconstruction: (x1*-x2*)=10μm
Soft DPE MC sample,
no other cuts applied
μ=0.5, β*=90m
– 10% impurity if T2 cut applied alone
– 1% together with baseline timing detectors
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
11
Glueballs in CD: motivation
Pomeron  colourless gluon pair/ladder  Pomeron fusion likely to produce glueballs
• f0(1500) & f0(1710) 0++ glueball candidates
• Lattice QCD [1]: m(0++) glueball  1700 (100) MeV  favours f0(1710)
• Show glueball mass hierarchy (uu, dd, ss, gg)  precise branching ratios (Br)
Open questions:
• f0(1500) mass, yields, decay channels and Br’s well measured, f0(1710) not
• Previous measurements (WA102 and predecessors) disfavoured f0(1710),
claiming Br(f0(1710)  KK) > Br(f0(1710)  ) & no f0(1710)  00
• Observation & measurement of f0(1710)  00 + new measurements of
Br(f0(1710)  KK) and Br(f0(1710)  ) would bring new knowledge
Limitations previous experiments:
• invariant mass / final state reach / purity/ mass resolution / assumptions
[1] Y. Chen et al., PRD73 (2006) 014516; C. J. Morningstar et al., PRD60 (1999) 034509
Low-mass spectroscopy
Integrated luminosity requirements
1. Sensitivity to the invariant mass
• Assuming a few events of f0(1710)4 in 2012 data (CMS-TOTEM run)
•  background simulated with DIME (large uncertainties) + CMS acceptance
MC, f0(1710)
MC, f0(1710)
MC, f0(1710)
–– sig.
–– bkg.
–– sig.
–– bkg.
–– sig.
–– bkg.
< 5 sign.
0.03pb-1
M [GeV]
X (unsatisfactory)
large background uncertainties
7 sign.
0.06pb-1
 (feasible)
M [GeV]
9 sign.
0.1pb-1
 (optimal)
M [GeV]
• Similar requirements from f0(1500)KK (well known channel)
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
13
Low-mass spectroscopy
Integrated luminosity requirements
2. Decay characterisation / calibration
• According to previous measurements f0(1710) should decay to KK as well
• Sensitivity to KK invariant mass (f0(1500)KK)
• Branching ratios for a low mass resonance differ by an order of magnitude
(e.g. for f0(1500) ΓKK = 9%, Γηη = 5%, Γ4π= 50%)
• At least a factor of 10 of int. luminosity increase is required to get access to
all decay modes
• With 1 pb-1 the coupling of glueballs to quarks could be fully studied:
glueballs may be confirmed or excluded
In total:
L = 0.3 pb-1
L = 0.6 pb-1
L = 1 pb-1
X (unsatisfactory)
 (feasible)
 (optimal)
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
14
Glueball searches, χc
3. Spin analysis requirements
• f2+2, acceptance modelled
• 𝐽 = 0 generated, 𝐽 = 0 and 𝐽 = 2 fitted
Azimuth angle difference Δϕ between 𝜋 + 𝜋 − pairs
–– J=0 gen.
–– J=0 fit
–– J=2 fit
200 events
2.3 rejection
Δ𝜑𝜚1𝜚2 [rad]
X (unsatisfactory)
–– J=0 gen.
–– J=0 fit
–– J=2 fit
300 events
5 rejection
Δ𝜑𝜚1𝜚2 [rad]
 (feasible)
–– J=0 gen.
–– J=0 fit
–– J=2 fit
400 events
6 rejection
Δ𝜑𝜚1𝜚2 [rad]
 (optimal)
Similar result for polar angle difference Δθ between 𝜋 + 𝜋 − pairs
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
15
Glueball searches, χc
• Purity of signal selection has to be verified with spin analysis
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–
–
–
Background (ρρ, ρππ, 4π)
Adjacent states compatible with exclusive CD: f2(1640), f2(1810)
Contamination by inclusive signal
Resonance coupling constants may change as a function of mass
• Individual contributions can be disentangled with an angular momentum
analysis as a function of M
• Small steps of a fraction of resonance widths’ allowed by mass resolution
of 30 MeV in the range of 1.3 GeV < M < 4 GeV (90 bins) required
In total:
40 bins  200 ev. = 8k ev.
ΔM = 70 MeV
L = 2 pb-1
65bins  300 ev. = 20k ev.
ΔM = 40 MeV
L = 4.8 pb-1
90 bins  400 ev. = 36k ev.
ΔM = 30 MeV
L = 10 pb-1
X (unsatisfactory)
 (feasible)
 (optimal)
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
16
Missing mass searches, ∫𝐿𝑑𝑡= 100pb-1
•
•
•
Large 𝑠, MCMS, MTOTEM= 𝑠𝜉1 𝜉2
|η|<6.5 covered by CMS tracker + CMS calorimeters + T1 + T2
Rapidity gaps protect from particles flowing into un-instrumented η-range
For ξ1,2<5%
•
•
Exclusive missing mass search (100 GeV scale pair of BSM particles):
– CMS+TOTEM empty + protective rapidity gaps + 2 non-elastic RP protons
Inclusive missing mass search (Mmissinga few 100GeV range)
𝑞 -𝑞 , with 𝑞 → 𝑞 + 𝜒 01 , with 𝜒 01 as LSP
Inclusive diffractive cross-section might be O(pb),
Characterised by large missing pT and jets
CMS-TOTEM could check current exclusion limits on (mgluino/squark  mLSP) for
gluinos/squarks in 150-250 GeV mass range
– No tight cuts on the momentum of the jets
– Exploration of (mgluino/squark  mLSP)  40 GeV
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–
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Running conditions
Ideal luminosity requirement : O(10 pb-1)
1 – 5 pb-1 will already produce physics results
Available beam conditions:
• 100 ns bunch spacing  702 bunches
• β*=90 m optics with crossing angle (±50 μrad)
• εN=2-3 μmrad, N < 1.51011
One week β*=90m (including setup), N=0.71011 (μ=0.13)
• Running scenario supported by experience from 2012 runs
• Agreed 2+1 days of setup & 1+1 day of physics in a single shot
(in calendar week foreseen by machine)
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
18
CMS-TOTEM
PRECISION PROTON SPECTROMETER
Detailed presentation by Joao Varela
LHCC CT PPS REFEREES SESSION
November 18, 2014
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
19
CT-PPS: Answers to referee’s questions
• Beam impedance
– Impedance budget for 4 horizontal RPs was validated by RF group (E. Metral) at
the beginning of the RP upgrade
– Observations done with non-optimised RPs in the past low-β* runs showed no
impact on beam stability
– RP impedance importantly improved (e.g. a factor of 6 lower heat intake)
– Wire tests of the final RP
– Beam stability to be rechecked in the 2015 exploratory phase
• Timing detector baseline solution is well defined
– Cherenkov L-bar Quartic detector
– (t) = 22 ps per arm target in the exploratory phase
• Preliminary timing and pixel detector schedules defined
• Physics programme: QCD, missing mass
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–
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Exclusive di-jets: quark-suppression rules tests
Inclusive di-jets: gluon distributions g(x,Q2) in pomeron
4-jet events: pomeron internal structure
The unexpected: M(X) > 250 GeV, M(JJ) spectrum in p + JJ + p
Hubert Niewiadomski
LHCC Open Session, 19 November 2014
20
Publications
•
Measurement of pseudorapidity distributions of charged particles in
proton–proton collisions at 𝑠 = 8 TeV by the CMS and TOTEM
experiments
Published, Eur. Phys. J. C (2014) 74:3053
•
LHC optics measurement with proton tracks detected by the Roman pots
of the TOTEM experiment
Published, New J. Phys. 16 (2014) 103041
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Measurement of the forward charged particle pseudorapidity density in pp
collisions at 𝑠 = 8 TeV using a displaced interaction point
CERN-PH-EP-2014-260, arXiv:1411.4963 [hep-ex], submitted to EPJC
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Evidence for Non-Exponential Elastic Differential Cross-Section at Low t
and 𝑠= 8 TeV by TOTEM at the CERN LHC, internal review
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Measurement of Elastic pp Scattering at 𝑠 = 8 TeV in the CoulombNuclear Interference Region by the TOTEM Experiment at the CERN LHC,
advanced, in progress
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Joint CMS-TOTEM note on low-mass resonances detected in common
June 2012 run, in progress
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Addendum to the TOTEM TDR, CERN-LHCC-2014-024
Thank you.