totem experiment status report - indico...edoardo bossini (on behalf of the totem collaboration)...

Totem Experiment Status Report

Edoardo Bossini

(on behalf of the TOTEM collaboration)

131st LHCC meeting

1

Outline

CT-PPS layout and acceptance Running operation Detector commissioning CT-PPS analysis status TOTEM: analysis status Future special runs

2 LHCC Open Session, 13 September 2017

LHCC Open Session, 13 September 2017

CT-PPS layout

CT-PPS currently running with all subdetectors installed. Four sensor technologies currently employed: • For Tracking Pixel and Strip silicon detectors • For timing sCVD diamond and UFSD. Timing technologies hosted in the same RP!

RP station involved: 210 far 220 far Timing RP

Also vertical (strip) used for alignment (see next slides)

3

4

CT-PPS acceptance

343 2353

437


5

TS1 operation

Replacement of 2 digitizer boards, new firmware for high trigger rates, replacement of cables Vertical lifting timng RP by 2.0 mm in sector 4/5 and 5/6

Vertical lifting has reestablished the acceptance of the timing detector after LHC beam optics changes in ip5

Continuous insertions of RPs were performed. All modifications approved by LHC MPP.

Temperature settings and cooling performance optimized

Exchange of Wiener Power supplies in sector 4/5 and 5/6 Service on cooling system – temperature regulation

Spurious beam dump by movement

interlock before TS1: Software update LVDT -> successful test of RP movement system

Timing detector consolidation


6

Delivered luminosity to CTPPS (11/9) ~ 17.5 /fb

RPs not inserted for

~ 1 week before

TS1 (~2.8 /fb lost)

Not official (till 29/8) :

LHC delivered ~ 19.5/fb

CMS recorded ~ 16.8/fb

After TS1 and after the LHC luminosity ramp-up, RP are inserted at each fill

LHC Delivered luminosity &

RP inserted ~13.5 /fb

Collected luminosity

+ 15 /fb of 2016


7

CT-PPS timing commissioning

• Due to the large data acquisition window for each trigger

(125 ns integration over 5 bunches) • Larger in UFSD (~6%) than in

diamond sensors (~4%) • Reduction to 50 ns leads to better

result, but still non negligible (~2 %) inefficiency is present

Relevant inefficiency (>5%) for multiple hits in the same channel

UFSD Diamond

To shrink to 25 ns time alignment of all channels needed

Performed at hardware level by tuning each channel


Multiple hit probability(%)

8



Multiple hit probability(%)

9

Correlation between strips and timing sensors demonstrated: • Search for hit in timing sensor • Reconstruct track in strip (if any) • Check if track point to the

expected timing pixel Diamond well centered w.r.t beam

Signal Time Over Threshold in the expected range, can be used for time walk correction


10

Tracker detector

Tracking detector hit map from may 2017 alignment run

11

Alignment data

Vertical RP (strip detector) needed for relative and global alignment: Vertical beam axis through

elastic hit distribution Relative alignment with

tracks in the overlap region

Horizontal beam axis through hit distribution on horizontal sensors (strip and pixel)


12

LHC clock is derived from CMS TCDS (Timing Control Distribution System)

System delay changes over optical path is constantly monitored -> 1 measurement every 10min.

Data stored to files in csv format file rotation system -> 1 file per day.

Clock jitter measured at RP receiver ~2ps

Clock system

New clock source based on Silicon Lab 5344 chip: • Zero delay mode constant phase delay

between input and output • Clock phase will be tuneable in ~18ps steps.


CT-PPS ongoing analysis

Dilepton (semi-)exclusive production:

• ~ 9.4 fb-1 of pre-TS2 (2016) data analyzed

• Single-arm matching between ξ(ll) and ξ(RP)

• μ+μ- channel: CMS-TOTEM Physics Analysis Summary

• e+e- channel: Ready for review

Search for exclusive di-photon production with sensitivity to four photon quartic anomalous couplings:

• Extraction of upper limits on the 𝛾𝛾 → 𝛾𝛾 production cross section at 13 TeV

• Translating into tight constraints on anomalous 4-𝛾 coupling

Exclusive 𝑊+𝑊−/𝑍𝑍 , missing mass & momentum...

13 LHCC Open Session, 13 September 2017

14

CT-PPS first physics results

Proof of operation at high luminosity with proton tagging

First CT-PPS physics outcome: high significance for di-lepton observation from 𝛾𝛾 process at this energy scale


TOTEM analysis

15

Run 1 analysis to be finalized / on-going: Single diffractive jets at 8 TeV – with CMS (being reviewed) Soft single diffraction @ 7 TeV Run 2 on-going analysis: Low mass resonances & glueballs - with CMS Exclusive charmonia– with CMS Single diffractive J/𝜓 & jets– with CMS Elastic scattering down to very low |t| (𝛽∗ = 2.5 km data) Luminosity independent 𝜎𝑡𝑜𝑡, 𝜎𝑖𝑛𝑒𝑙 , 𝜎𝑒𝑙 at 13 Tev

(more on that in next slides)


98.0 2.5 mb

98.6 2.2 mb

95.35 1.36 mb

96.07 0.92 mb

101.5 2.1 mb

102.9 2.3 mb


TOTEM total cross section measurements

Selection of

TOTEM

measurements with

different energies,

methodologies,

systematics and

data samples.

7 8 2.76 0.9 TeV

TOTEM

Upcoming results and low energy run

13

Analyses well advanced with b*=2.5 km and b*=90m. Same steps as in 8 TeV publication

Upcoming results and low energy run

18

Low energy run (900 GeV), where no pp data are available, will greatly improve our understanding of the energy dependence

High precision (±0.01) 𝜌 measurement ongoing at 13 TeV


19

Conclusion/outlook

All technologies working, RP are inserted at each fill.

TS1 operations greatly improve system performance and stability.

Timing sensors under commissioning. Correlation with strip tracking detector confirmed. TOT in the expected range.

All tracker detector fully integrated in CMS. Relative and global alignment performed

Optical clock source improved with constant phase pll. Measured Jitter at RP location ~2 ps.

Analyses are ongoing both in CT-PPS and TOTEM. 1° paper from CT-PPS

Future low energy run will help to understand the 𝜌 behavior w.r.t. energy (as well the cross section)


22

( 210-N)

210-F

220-C

B1 B2

220-F safety limit

( ) not used

X

a/2 = 150 mrad 100 mrad

X X

ATS “option 3bis”

b* = 0.40 m,

dRP = 12 s + 0.3 mm

b* = 0.30 m, a/2 = 175 mrad,

dRP = 11.5 s + 0.3 mm

b* = 0.30 m, a/2 = 175 mrad,

dRP = 10.5 s + 0.3 mm

23 Synch with triggered bunch

Channel by channel calibration at hardware level performed: Data alignment before event

building Bunch structure visible Possible to select a 25 ns

acquisition window

Signal time (ns) Signal time (ns)

Signal time (ns)


Optical clock commissioning

– Check of fibers attenuation 3-4dB

– RMS jitter at source ~1ps

– RMS jitter at receivers ~2ps

24

CMS USC55

LHC- sector 56

Jitter measurement

LHC- sector 45

totem experiment status report - indico...edoardo bossini (on behalf of the totem collaboration)...

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