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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





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:
•
•
•
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):
•
•
•
•
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)
•
•
•
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
–
–
–
–
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
–
–
–
–
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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–
–
–
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
•
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
•
Evidence for Non-Exponential Elastic Differential Cross-Section at Low t
and 𝑠= 8 TeV by TOTEM at the CERN LHC, internal review
•
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
•
Joint CMS-TOTEM note on low-mass resonances detected in common
June 2012 run, in progress
•
Addendum to the TOTEM TDR, CERN-LHCC-2014-024
Thank you.