First results at the lhc seen through the eyes of alice
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

First Results at the LHC seen through the eyes of ALICE PowerPoint PPT Presentation


  • 48 Views
  • Uploaded on
  • Presentation posted in: General

First Results at the LHC seen through the eyes of ALICE. Научный руководитель – . Курепин А.Б Координатор - Каравичева Т.Л. Коллектив участников : ЛМЯВ : Губер Ф.Ф. ,Карпечев Е.Н., Коневских А., Маевская А.И., Решетин А.И., Тифлов В.В.

Download Presentation

First Results at the LHC seen through the eyes of ALICE

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


First results at the lhc seen through the eyes of alice

First Results at the LHCseen through the eyes of ALICE

Научный руководитель – . Курепин А.Б

Координатор - Каравичева Т.Л.

Коллектив участников :

ЛМЯВ : Губер Ф.Ф. ,Карпечев Е.Н.,

Коневских А., Маевская А.И.,

Решетин А.И., Тифлов В.В.

КОРЭ: Аношко А.С., Веселовский А.В.,

Каравичев О.В., Курепин А.Н.,

Марин В.И.,Тихонов А.А.


First results at the lhc seen through the eyes of alice

T0 and V0

V0C

V0A

IP

RB26

RB24

T0-A

T0-C

T0-C


T0 detector

T0 detector

Precise start signal for TOF

  • (time resolution of about 50 ps)

    Trigger functions (on-line):

  • Rough vertex position

    position resolution (along the beam direction)  1 cm;

  • Rough multiplicity

  • vertex-independent interaction time

    “wake-up” signal to TRD

    The past-future protection

    Luminosity using T0


Some anxious minutes waiting for collisions

some anxious minutes waiting for collisions..

~ 16:35


The first event pops up in the acr

The first ‘event’ pops up in the ACR

.

~ 16:41

Fig. 1. The first pp collision candidate shown by the event display in the ALICE counting room (3D view, r-_ and r-z

projections), the dimensions are shown in cm. The dots correspond to hits in the silicon vertex detectors (SPD, SDD and SSD),

the lines correspond to tracks reconstructed using loose quality cuts. The ellipse drawn in the middle of the detector surrounds

the reconstructed event vertex


Interaction in vertex between t0 a and t0 c green integrated 60s interaction rate magenta

Trigger rate ~30 Hz

T0vx ~5.9 Hz ( ~19 %)

Simulation rate ~18,8 %

Interaction in vertex between T0_A and T0_C (green). Integrated (60s) interaction rate (magenta).

hit rates per second for each PMT

Total number of hits

for each PMT


First results at the lhc seen through the eyes of alice

RUN 104321

RAW+

slewing corr

RAW

CFDC1-CFDC2

Time resolution

(2.39/1.41) *24.4=42 ps


Physics exploitation of alice has started for good

»p

This is the first (and easiest) of

many numbers we need to (re)measure to

get confidence in our detectors, tune the

simulations, study background, ....

Phase 2 is still a long way to go..

last time measured at the ISR for pp

Physics exploitation of ALICE has started for good !

Phase 1: rediscovering the standard model

(QCD in the case of ALICE)

submitted to EPJC 28 Nov 2009

The average number of charged particles

created perpendicular to the beam

in pp collisions at 900 GeV is:

dN/dh = 3.10 ± 0.13 (stat) ± 0.22 (syst)


Particle identification

all plots:

preliminary calibration & alignment !

TOF

Protons

Kaons

Pions

TOF PID spectra

to study particle production

velocity v/c

Particle identification

On 6th December, ‘stable beams’

were declared & we could switch on

all ALICE detectors for the first time..

Total events collected: > 1 M

‘Good pp interactions’: 500 k

- 100 k : B = 0 (alignment)

- 10 k : B reversed (systematics)

- 30 k : √s = 2.36 TeV

ALICE special: Particle Identification

(very important for heavy ion physics later in 2010)


Tracking works beautifully

Beam spot at 2.36 TeV

SPD Vertex resolution versus # tracks

preliminary alignment !

Tracking works beautifully


Finally

LHC

Ös = 900 GeV

Finally…

Work in progress..

dN/dh at 2.36 TeV

statistical error negligible

final systematic error under evaluation

(still 7% for the time being)

LHC

Ös = 2.36 TeV


First results at the lhc seen through the eyes of alice

ALICE is a very happy (and busy) girl right now


  • Login