{
  "id": 16755,
  "title": "A picture for explaining dira, IP and flight distance",
  "url": "/competitions/flavours-of-physics/discussion/16755",
  "author_name": "",
  "post_date": "2015-10-01T18:06:09.720Z",
  "votes": 7,
  "comment_count": 6,
  "views": 839,
  "content": "<p>Just realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from <a href=\"https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/\">https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/</a> (good to read about the background of this LFV search)\n<img src=\"https://dl.dropboxusercontent.com/u/10652630/kaggle/tau-3mu.png\" alt=\"enter image description here\" title></p>",
  "messages": [
    {
      "id": "93812",
      "postDate": "10/01/2015 18:06:09",
      "content": "<p>Just realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from <a href=\"https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/\">https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/</a> (good to read about the background of this LFV search)\n<img src=\"https://dl.dropboxusercontent.com/u/10652630/kaggle/tau-3mu.png\" alt=\"enter image description here\" title></p>",
      "rawMarkdown": "Just realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/ (good to read about the background of this LFV search)\r\n![enter image description here][1]\r\n\r\n\r\n  [1]: https://dl.dropboxusercontent.com/u/10652630/kaggle/tau-3mu.png",
      "votes": null
    },
    {
      "id": "93863",
      "postDate": "10/02/2015 10:34:00",
      "content": "<p>[quote=phunter;93812]</p>\n\n<p>Just realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from <a href=\"https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/\">https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/</a> (good to read about the background of this LFV search)\n![enter image description here][1]\n[/quote]</p>\n\n<p>phunter thank you, I can say, you are a real researcher, who really want to get the best answer to the questions at (almost) whatever cost and makes real effort to reach the best solution here.\nCould you please mention something about the flight distance error too or some link?</p>",
      "rawMarkdown": "[quote=phunter;93812]\r\n\r\nJust realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/ (good to read about the background of this LFV search)\r\n![enter image description here][1]\r\n[/quote]\r\n\r\nphunter thank you, I can say, you are a real researcher, who really want to get the best answer to the questions at (almost) whatever cost and makes real effort to reach the best solution here.\r\nCould you please mention something about the flight distance error too or some link?",
      "votes": null
    },
    {
      "id": "93899",
      "postDate": "10/02/2015 15:45:54",
      "content": "<p>flight distance error is the measurement error of flight distance: it comes from the position error of primary vertex and the position error of the tau vertex where Ds becomes tau. IP also has errors but the data provides the significance of IP measurement (<a href=\"https://en.wikipedia.org/wiki/Statistical_significance\">https://en.wikipedia.org/wiki/Statistical_significance</a>)</p>\n\n<p>Plus, you might also want to check the invariant mass of Ds vs Tau, which can give a hint of your feature engineering on the kinematic features.</p>",
      "rawMarkdown": "flight distance error is the measurement error of flight distance: it comes from the position error of primary vertex and the position error of the tau vertex where Ds becomes tau. IP also has errors but the data provides the significance of IP measurement (https://en.wikipedia.org/wiki/Statistical_significance)\r\n\r\nPlus, you might also want to check the invariant mass of Ds vs Tau, which can give a hint of your feature engineering on the kinematic features.",
      "votes": null
    },
    {
      "id": "93926",
      "postDate": "10/02/2015 20:39:34",
      "content": "<p>Thank you very much, Sir!</p>",
      "rawMarkdown": "Thank you very much, Sir!",
      "votes": null
    },
    {
      "id": "95090",
      "postDate": "10/04/2015 23:42:41",
      "content": "<p>[quote=George Solymosi;93926]</p>\n\n<p>Thank you very much, Sir!</p>\n\n<p>[/quote]\nSee your recent giant leap on the LB, nice, you must have found some very nice features.</p>",
      "rawMarkdown": "[quote=George Solymosi;93926]\r\n\r\nThank you very much, Sir!\r\n\r\n[/quote]\r\nSee your recent giant leap on the LB, nice, you must have found some very nice features.",
      "votes": null
    },
    {
      "id": "95144",
      "postDate": "10/05/2015 13:44:30",
      "content": "<p>[quote]\nSee your recent giant leap on the LB, nice, you must have found some very nice features.</p>\n\n<p>[/quote]</p>\n\n<p>I wish I could be, but still working on it. As I am newbie in datascience my first purpose  was to align my CV with LB as you maybe saw. Though I'm quite happy that I found it out, unfortunately I struggled and waisted  a lot of time with this phase instead of found some magic feature. Thus I have a bit few time to the end of this competition, so for a new sensation of mine for physics perhaps I have to wait till the next CERN competition. This result is just a kind of fillip (still). :)\nThough - as I mentioned - continuously working on the features.</p>",
      "rawMarkdown": "[quote]\r\nSee your recent giant leap on the LB, nice, you must have found some very nice features.\r\n\r\n[/quote]\r\n\r\nI wish I could be, but still working on it. As I am newbie in datascience my first purpose  was to align my CV with LB as you maybe saw. Though I'm quite happy that I found it out, unfortunately I struggled and waisted  a lot of time with this phase instead of found some magic feature. Thus I have a bit few time to the end of this competition, so for a new sensation of mine for physics perhaps I have to wait till the next CERN competition. This result is just a kind of fillip (still). :)\r\nThough - as I mentioned - continuously working on the features.",
      "votes": null
    },
    {
      "id": "95145",
      "postDate": "10/05/2015 14:03:31",
      "content": "",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 93863,
      "author_name": "",
      "author_url": "",
      "post_date": "10/02/2015 10:34:00",
      "content": "<p>[quote=phunter;93812]</p>\n\n<p>Just realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from <a href=\"https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/\">https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/</a> (good to read about the background of this LFV search)\n![enter image description here][1]\n[/quote]</p>\n\n<p>phunter thank you, I can say, you are a real researcher, who really want to get the best answer to the questions at (almost) whatever cost and makes real effort to reach the best solution here.\nCould you please mention something about the flight distance error too or some link?</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 93899,
      "author_name": "phunter",
      "author_url": "",
      "post_date": "10/02/2015 15:45:54",
      "content": "<p>flight distance error is the measurement error of flight distance: it comes from the position error of primary vertex and the position error of the tau vertex where Ds becomes tau. IP also has errors but the data provides the significance of IP measurement (<a href=\"https://en.wikipedia.org/wiki/Statistical_significance\">https://en.wikipedia.org/wiki/Statistical_significance</a>)</p>\n\n<p>Plus, you might also want to check the invariant mass of Ds vs Tau, which can give a hint of your feature engineering on the kinematic features.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 93926,
      "author_name": "",
      "author_url": "",
      "post_date": "10/02/2015 20:39:34",
      "content": "<p>Thank you very much, Sir!</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 95090,
      "author_name": "phunter",
      "author_url": "",
      "post_date": "10/04/2015 23:42:41",
      "content": "<p>[quote=George Solymosi;93926]</p>\n\n<p>Thank you very much, Sir!</p>\n\n<p>[/quote]\nSee your recent giant leap on the LB, nice, you must have found some very nice features.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 95144,
      "author_name": "",
      "author_url": "",
      "post_date": "10/05/2015 13:44:30",
      "content": "<p>[quote]\nSee your recent giant leap on the LB, nice, you must have found some very nice features.</p>\n\n<p>[/quote]</p>\n\n<p>I wish I could be, but still working on it. As I am newbie in datascience my first purpose  was to align my CV with LB as you maybe saw. Though I'm quite happy that I found it out, unfortunately I struggled and waisted  a lot of time with this phase instead of found some magic feature. Thus I have a bit few time to the end of this competition, so for a new sensation of mine for physics perhaps I have to wait till the next CERN competition. This result is just a kind of fillip (still). :)\nThough - as I mentioned - continuously working on the features.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 95145,
      "author_name": "",
      "author_url": "",
      "post_date": "10/05/2015 14:03:31",
      "content": "",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "93812": "Just realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/ (good to read about the background of this LFV search)\r\n![enter image description here][1]\r\n\r\n\r\n  [1]: https://dl.dropboxusercontent.com/u/10652630/kaggle/tau-3mu.png",
    "93863": "[quote=phunter;93812]\r\n\r\nJust realized this problem from my teammates about understanding these kinematic variables, so I draw this picture and marked these features on the picture so other competitors may get some ideas of feature engineering. Please correct me if I understood it wrong. The original picture comes from https://muon.wordpress.com/2014/10/04/lhcb-searches-for-lfv-in-tau-decays/ (good to read about the background of this LFV search)\r\n![enter image description here][1]\r\n[/quote]\r\n\r\nphunter thank you, I can say, you are a real researcher, who really want to get the best answer to the questions at (almost) whatever cost and makes real effort to reach the best solution here.\r\nCould you please mention something about the flight distance error too or some link?",
    "93899": "flight distance error is the measurement error of flight distance: it comes from the position error of primary vertex and the position error of the tau vertex where Ds becomes tau. IP also has errors but the data provides the significance of IP measurement (https://en.wikipedia.org/wiki/Statistical_significance)\r\n\r\nPlus, you might also want to check the invariant mass of Ds vs Tau, which can give a hint of your feature engineering on the kinematic features.",
    "93926": "Thank you very much, Sir!",
    "95090": "[quote=George Solymosi;93926]\r\n\r\nThank you very much, Sir!\r\n\r\n[/quote]\r\nSee your recent giant leap on the LB, nice, you must have found some very nice features.",
    "95144": "[quote]\r\nSee your recent giant leap on the LB, nice, you must have found some very nice features.\r\n\r\n[/quote]\r\n\r\nI wish I could be, but still working on it. As I am newbie in datascience my first purpose  was to align my CV with LB as you maybe saw. Though I'm quite happy that I found it out, unfortunately I struggled and waisted  a lot of time with this phase instead of found some magic feature. Thus I have a bit few time to the end of this competition, so for a new sensation of mine for physics perhaps I have to wait till the next CERN competition. This result is just a kind of fillip (still). :)\r\nThough - as I mentioned - continuously working on the features.",
    "95145": ""
  },
  "source": "meta"
}